diff --git "a/fypmc20277423/training.txt" "b/fypmc20277423/training.txt" deleted file mode 100644--- "a/fypmc20277423/training.txt" +++ /dev/null @@ -1,32912 +0,0 @@ -Book1: -benefits and risks associated with physical activity r e t p a h c 1 introduction th e purpose of this chapter is to provide current information on the bene ts and risks of physical activity (pa) and/or exercise. -for clari cation purposes, key terms used throughout the guidelines related to pa and tness are de ned in this chapter. -additional information speci c to a disease, disability, or health condi- tion are explained within the context of the chapter in which they are discussed in the guidelines . -pa continues to take on an increasingly important role in the prevention and treatment of multiple chronic diseases, health conditions, and their associated risk factors. -th erefore, chapter 1 focuses on the public health per- spective that forms the basis for the current pa recommendations ( 5 , 26 , 34 , 70 , 93 ). -chapter 1 concludes with recommendations for reducing the incidence and severity of exercise-related complications for primary and secondary prevention programs. -physical activity and fitness terminology pa and exercise are oft en used interchangeably, but these terms are not synon- ymous. -pa is de ned as any bodily movement produced by the contraction of skeletal muscles that results in a substantial increase in caloric requirements over resting energy expenditure ( 14 , 78 ). -exercise is a type of pa consisting of planned, structured, and repetitive bodily movement done to improve and/or maintain one or more components of physical tness ( 14 ). -physical tness has been de ned in several ways, but the generally accepted de nition is the ability to carry out daily tasks with vigor and alertness, without undue fatigue, and with ample energy to enjoy leisure-time pursuits and meet unforeseen emergencies ( 76 ). -physical tness is composed of various elements that can be further grouped into health-related and skill-related components which are de ned in box 1.1 . -in addition to de ning pa, exercise, and physical tness, it is important to clearly de ne the wide range of intensities associated with pa (see table 6.1 ). -methods for quantifying the relative intensity of pa include specifying a percentage 1 2 guidelines for exercise testing (cid:129) www.acsm.org box 1.1 health-related and skill-related components of physical fitness health-related physical fitness components cardiorespiratory endurance: the ability of the circulatory and respiratory system to supply oxygen during sustained physical activity body composition: the relative amounts of muscle, fat, bone, and other vital parts of the body muscular strength: the ability of muscle to exert force muscular endurance: the ability of muscle to continue to perform without fatigue flexibility: the range of motion available at a joint skill-related physical fitness components agility: the ability to change the position of the body in space with speed and accuracy coordination: the ability to use the senses, such as sight and hearing, together with body parts in performing tasks smoothly and accurately balance: the maintenance of equilibrium while stationary or moving power: the ability or rate at which one can perform work reaction time: the time elapsed between stimulation and the beginning of the reaction to it speed: the ability to perform a movement within a short period of time adapted from ( 96 ). -available from http://www.fitness.gov/digest_mar2000.htm o 2 r), heart rate reserve (hrr), oxygen consumption of oxygen uptake reserve (v (v o 2 ), heart rate (hr), or metabolic equivalents (mets) (see box 6.2 ). -each of these methods for describing the intensity of pa has strengths and limitations. -although determining the most appropriate method is left to the exercise profes- sional, chapter 6 provides the methodology and guidelines for selecting a suitable method. -mets are a useful, convenient, and standardized way to describe the absolute intensity of a variety of physical activities. -light intensity pa is de ned as requir- ing 2.0 2.9 mets, moderate as 3.0 5.9 mets, and vigorous as (cid:2)6.0 mets ( 26 ). -table 1.1 gives speci c examples of activities in mets for each of the intensity ranges. -a complete list of physical activities and their associated estimates of en- ergy expenditure can be found elsewhere ( 2 ). -maximal aerobic capacity usually declines with age ( 26 ). -for this reason, when older and younger individuals work at the same met level, the relative exercise in- o 2max ) will usually be di erent (see chapter 6 ). -in other words, the tensity ( e.g. -, %v older individual will be working at a greater relative percentage of maximal oxygen o 2max ) than their younger counterparts. -nonetheless, physically consumption (v active older adults may have aerobic capacities comparable to or greater than those of physically inactive younger adults. -chapter 1 bene ts and risks associated with physical activity 3 table 1.1 metabolic equivalents (mets) values of common physical activities classified as light, moderate, or vigorous intensity very light/light ((cid:2)3.0 mets) moderate (3.0 5.9 mets) vigorous ((cid:3)6.0 mets) walking walking slowly around home, store, or of ce (cid:3) 2.0a household and occupation standing performing light work, such as making bed, washing dishes, ironing, preparing food, or store clerk (cid:3) 2.0 2.5 leisure time and sports arts and crafts, playing cards (cid:3) 1.5 billiards (cid:3) 2.5 boating power (cid:3) 2.5 croquet (cid:3) 2.5 darts (cid:3) 2.5 fishing sitting (cid:3) 2.5 playing most musical instru- ments (cid:3) 2.0 2.5 walking walking 3.0 mi (cid:2) h(cid:4)1 (cid:3) 3.0a walking at very brisk pace (4 mi (cid:2) h(cid:4)1) (cid:3) 5.0a household and occupation cleaning, heavy washing windows, car, clean garage (cid:3) 3.0 sweeping oors or carpet, vacuuming, mopping (cid:3) 3.0 3.5 carpentry general (cid:3) 3.6 carrying and stacking wood (cid:3) 5.5 walking, jogging, and running walking at very, very brisk pace (4.5 mi (cid:2) h(cid:4)1) (cid:3) 6.3a walking/hiking at moderate pace and grade with no or light pack ((cid:5)10 lb) (cid:3) 7.0 hiking at steep grades and pack 10 42 lb (cid:3) 7.5 9.0 jogging at 5 mi (cid:2) h(cid:4)1 (cid:3) 8.0a jogging at 6 mi (cid:2) h(cid:4)1 (cid:3) 10.0a running at 7 mi (cid:2) h(cid:4)1 (cid:3) 11.5a household and occupation shoveling sand, coal, etc. -(cid:3) 7.0 mowing lawn walk power carrying heavy loads, such mower (cid:3) 5.5 leisure time and sports badminton recreational (cid:3) 4.5 basketball shooting around (cid:3) 4.5 dancing ballroom slow (cid:3) 3.0; ballroom fast (cid:3) 4.5 fishing from riverbank and walking (cid:3) 4.0 golf walking, pulling clubs (cid:3) 4.3 sailing boat, wind sur ng (cid:3) 3.0 table tennis (cid:3) 4.0 tennis doubles (cid:3) 5.0 volleyball noncompetitive (cid:3) 3.0 4.0 as bricks (cid:3) 7.5 heavy farming, such as bailing hay (cid:3) 8.0 shoveling, digging ditches (cid:3) 8.5 leisure time and sports bicycling on at light effort (10 12 mi (cid:2) h(cid:4)1) (cid:3) 6.0 basketball game (cid:3) 8.0 bicycling on at moderate effort (12 14 mi (cid:2) h(cid:4)1) (cid:3) 8.0; fast (14 16 mi (cid:2) h(cid:4)1) (cid:3) 10.0 skiing cross-country slow (2.5 mi (cid:2) h(cid:4)1) (cid:3) 7.0; fast (5.0 7.9 mi (cid:2) h(cid:4)1) (cid:3) 9.0 soccer casual (cid:3) 7.0; competitive (cid:3) 10.0 swimming leisurely (cid:3) 6.0b; swimming moderate/ hard (cid:3) 8.0 11.0b tennis singles (cid:3) 8.0 volleyball competitive at gym or beach (cid:3) 8.0 a on at, hard surface. -b met values can vary substantially from individual to individual during swimming as a result of differ- ent strokes and skill levels. -adapted from ( 2 ). -4 guidelines for exercise testing (cid:129) www.acsm.org public health perspective for current recommendations over 20 yr ago, the american college of sports medicine (acsm) in conjunc- tion with the centers for disease control and prevention (cdc) ( 73 ), the u.s. surgeon general ( 93 ), and the national institutes of health ( 75 ) issued landmark publications on pa and health. -an important goal of these reports was to clarify for exercise professionals and the public the amount and intensity of pa needed to improve health, lower susceptibility to disease (morbidity), and decrease premature mortality ( 73 , 75 , 93 ). -in addition, these reports documented the dose-response re- lationship between pa and health ( i.e. -, some activity is better than none, and more activity, up to a point, is better than less). -in 1995, the cdc and acsm recommended that every u.s. adult should accumulate 30 min or more of moderate pa on most, preferably all, days of the week ( 73 ). -th e intent of this statement was to increase public awareness of the importance of the health-related bene ts of moderate intensity pa. as a result of an increasing awareness of the adverse health e ects of physical inactivity and because of some confusion and misinterpretation of the original pa recom- mendations, the acsm and american heart association (aha) issued updated recommendations for pa and health in 2007 ( box 1.2 ) ( 34 ). -more recently, the federal government convened an expert panel, the 2008 physical activity guidelines advisory committee, to review the scienti c ev- idence on pa and health published since the 1996 u.s. surgeon general s report ( 76 ). -th is committee found compelling evidence regarding the bene ts of pa for health as well as the presence of a dose-response relationship for many dis- eases and health conditions. -two important conclusions from the physical activity box 1.2 the acsm-aha primary physical activity (pa) recommendations ( 33 ) all healthy adults aged 18 65 yr should participate in moderate intensity aer- obic pa for a minimum of 30 min on 5 d (cid:2) wk (cid:4)1 or vigorous intensity aerobic activity for a minimum of 20 min on 3 d (cid:2) wk (cid:4)1 . -combinations of moderate and vigorous intensity exercise can be performed to meet this recommendation. -moderate intensity aerobic activity can be accumulated to total the 30 min minimum by performing bouts each lasting (cid:2)10 min. -every adult should perform activities that maintain or increase muscular strength and endurance for a minimum of 2 d (cid:2) wk (cid:4)1 . -because of the dose-response relationship between pa and health, individuals who wish to further improve their fitness, reduce their risk for chronic diseases and disabilities, and/or prevent unhealthy weight gain may benefit by exceed- ing the minimum recommended amounts of pa. acsm, american college of sports medicine; aha, american heart association. -chapter 1 bene ts and risks associated with physical activity 5 guidelines advisory committee report that in uenced the development of the pa recommendations are the following: important health bene ts can be obtained by performing a moderate amount of pa on most, if not all, days of the week. -additional health bene ts result from greater amounts of pa. individuals who maintain a regular program of pa that is longer in duration, of greater intensity, or both are likely to derive greater bene t than those who engage in lesser amounts. -similar recommendations have been made in the 2008 federal pa guidelines ( http://www.health.gov/paguidelines ) ( 93 ) based on the 2008 physical activity guidelines advisory committee report ( 76 ) ( box 1.3 ). -since the release of the u.s. surgeon general s report in 1996 ( 93 ), several reports have advocated pa levels above the minimum cdc-acsm pa recommendations ( 22 , 26 , 80 , 92 ). -th ese guidelines and recommendations primarily refer to the volume of pa required to prevent weight gain and/or obesity and should not be viewed as contradictory. -in other words, pa that is su cient to reduce the risk of developing chronic diseases and delaying mortality may be insu cient to prevent or reverse weight gain and/or obesity given the typical american lifestyle. -pa beyond the min- imum recommendations combined with proper nutrition is likely needed in many individuals to manage and/or prevent weight gain and obesity ( 22 , 42 ). -several large-scale epidemiology studies have been performed that docu- ment the dose-response relationship between pa and cardiovascular disease (cvd) and premature mortality ( 52 , 57 , 72 , 79 , 88 , 107 ). -williams ( 104 ) performed a meta-analysis of 23 sex-speci c cohorts reporting varying levels of pa or cardio- respiratory tness (crf) representing 1,325,004 individual-years of follow-up and showed a dose-response relationship between pa or crf and the risks of coronary artery disease (cad) and cvd ( figure 1.1 ). -it is clear that greater amounts of pa or increased crf levels provide additional health bene ts. -table 1.2 provides the box 1.3 the primary physical activity recommendations from the 2008 physical activity guidelines advisory committee report ( 93 ) all americans should participate in an amount of energy expenditure equivalent to 150 min (cid:2) wk (cid:4)1 of moderate intensity aerobic activity, 75 min (cid:2) wk (cid:4)1 of vigorous intensity aerobic activity, or a combination of both that generates energy equivalency to either regimen for substantial health benefits. -these guidelines further specify a dose-response relationship, indicating addi- tional health benefits are obtained with 300 min (cid:2) wk (cid:4)1 or more of moderate inten- sity aerobic activity, 150 min (cid:2) wk (cid:4)1 or more of vigorous intensity aerobic activity, or an equivalent combination of moderate and vigorous intensity aerobic activity. -adults should do muscle strengthening activities that are moderate or high intensity and involve all major muscle groups in (cid:2)2 d (cid:2) wk (cid:4)1 because these activities provide additional health benefits. -6 guidelines for exercise testing (cid:129) www.acsm.org 1 0.8 0.6 0.4 k s i r e v i t a l e r 0.2 0 physical activity physical fitness 25 50 75 100 percentage figure 1.1 estimated dose-response curve for the relative risk of atherosclerotic cardio- vascular disease by sample percentages of tness and physical activity. -studies weighted by individual-years of experience. -used with permission from ( 104 ). -strength of evidence for the dose-response relationships among pa and numerous health outcomes. -th e acsm and aha have also released two publications examining the relationship between pa and public health in older adults ( 5 , 70 ). -in general, these publications o ered some recommendations that are similar to the updated guide- lines for adults ( 26,34 ), but the recommended intensity of aerobic activity re ected in these guidelines is related to the older adult s crf level. -in addition, age-speci c recommendations are made concerning the importance of exibility, neuromotor, and muscle strengthening activities. -th e 2008 physical activity guidelines for amer- icans made age-speci c recommendations targeted at adults (18 64 yr) and older adults ((cid:2)65 yr) as well as children and adolescents (6 17 yr) ( http://www.health.gov/ paguidelines ) ( 93 ) that are similar to recommendations by the acsm and aha. -despite the well-known health bene ts, physical inactivity is a global pandemic that has been identi ed as one of the four leading contributors to premature mortal- ity ( 30 , 50 ). -globally, 31.1% of adults are physically inactive ( 30 ). -in the united states, 51.6% of adults meet aerobic activity guidelines, 29.3% meet muscle strengthening guidelines, and 20.6% meet both the aerobic and muscle strengthening guidelines ( 15 ). -sedentary behavior and health prolonged periods of sitting or sedentary behavior are associated with deleterious health consequences (see chapter 6 ) ( 35 , 36 , 44 , 47 ) independent of pa levels ( 8 , 51 , 63 , 82 ). -th is is concerning from a public health perspective because population-based studies have demonstrated that more than 50% of an average person s waking day in- volves activities associated with prolonged sitting such as television viewing and com- puter use ( 62 ). -a recent meta-analysis demonstrated that aft er statistical adjustment chapter 1 bene ts and risks associated with physical activity 7 table 1.2 evidence for dose-response relationship between physical activity and health outcome variable all-cause mortality cardiorespiratory health metabolic health energy balance: weight maintenance weight loss weight maintenance following weight loss abdominal obesity musculoskeletal health: bone joint muscular functional health colon and breast cancers mental health: depression and distress well-being: evidence for a dose- response relationship strength of evidencea yes yes yes insuf cient data yes yes yes yes yes yes yes yes yes strong strong moderate weak strong moderate moderate moderate strong strong moderate moderate moderate anxiety, cognitive health, and sleep insuf cient data weak a strength of the evidence was classi ed as follows: strong strong, consistent across studies and populations moderate moderate or reasonable, reasonably consistent weak weak or limited, inconsistent across studies and populations adapted from ( 76 ). -for pa, sedentary time was independently associated with a greater risk for all-cause mortality, cvd incidence or mortality, cancer incidence or mortality (breast, colon, colorectal, endometrial, and epithelial ovarian), and type 2 diabetes mellitus (t2dm) in adults ( 8 ). -however, sedentary time was associated with a 30% lower relative risk for all-cause mortality among those with high levels of pa as compared with those with low levels of pa, suggesting that the adverse outcomes associated with sedentary time decrease in magnitude among persons who are more physically active ( 8 ). -health benefits of regular physical activity and exercise evidence to support the inverse relationship between regular pa and/or exercise and premature mortality, cvd/cad, hypertension, stroke, osteoporosis, t2dm, 8 guidelines for exercise testing (cid:129) www.acsm.org metabolic syndrome (metsyn), obesity, 13 cancers (breast, bladder, rectal, head and neck, colon, myeloma, myeloid leukemia, endometrial, gastric cardia, kid- ney, lung, liver, esophageal adenocarcinoma), depression, functional health, falls, and cognitive function continues to accumulate ( 26 , 67 , 76 ). -for many of these diseases and health conditions, there is also strong evidence of a dose-response relationship with pa (see table 1.2 ). -th is evidence has resulted from clinical intervention studies as well as large-scale, population-based, observational studies ( 26 , 34 , 37 , 45 , 54 , 69 , 94 , 100 , 103 ). -several large-scale epidemiology studies have clearly documented a dose- response relationship between pa and risk of cvd and premature mortality in men and women and in ethnically diverse participants ( 52 , 57 , 69 , 71 , 76 , 88 , 107 ). -it is also important to note that aerobic capacity ( i.e. -, crf) has an inverse relation- ship with risk of premature death from all causes and speci cally from cvd, and higher levels of crf are associated with higher levels of habitual pa, which in turn are associated with many health bene ts ( 10 , 11 , 26 , 49 , 84 , 99 , 103 ). -box 1.4 summa- rizes the bene ts of regular pa and/or exercise. -health benefits of improving muscular fitness th e health bene ts of enhancing muscular tness ( i.e. -, the functional parameters of muscle strength, endurance, and power) are well established ( 26 , 93 , 102 ). -higher levels of muscular strength are associated with a signi cantly better cardiometabolic risk factor pro le, lower risk of all-cause mortality, fewer cvd events, lower risk of developing physical function limitations, and lower risk for nonfatal disease ( 26 ). -th ere is an impressive array of changes in health-related biomarkers that can be derived from regular participation in resistance training including improvements in body composition, blood glucose levels, insulin sensitivity, and blood pressure in individuals with mild or moderate hypertension ( 17 , 26 , 74 ). -recent evidence suggests that resistance training is as e ective as aerobic training in the manage- ment and treatment of t2dm ( 106 ) and in improving the blood lipid pro les of individuals who are overweight/obese ( 83 ). -resistance training positively af- fects walking distance and velocity in those with peripheral artery disease (pad) ( 6 , 106 ). -further health bene ts attributed to resistance training were con rmed by a recent meta-analysis of published reports which revealed that regimens featuring mild-to-moderate intensity isometric muscle actions were more e ective in reduc- ing blood pressure in both normotensive and hypertensive people than aerobic training or dynamic resistance training ( 13 ). -accordingly, resistance training may be e ective for preventing and treating the dangerous constellation of conditions referred to as metsyn ( 26 ) (see chapter 10 ). -exercise that enhances muscle strength and mass also increases bone mass ( i.e. -, bone mineral density and content) and bone strength of the speci c bones stressed and may serve as a valuable measure to prevent, slow, or reverse the loss of bone mass in individuals with osteoporosis ( 5 , 26 , 93 ) (see chapter 11 ). -resistance training can reduce pain and disability in individuals with osteoarthritis ( 26 , 65 ) and has been shown to be e ective in the treatment of chronic back pain ( 57 , 97 ). -chapter 1 bene ts and risks associated with physical activity 9 box 1.4 benefits of regular physical activity and/or exercise improvement in cardiovascular and respiratory function increased maximal oxygen uptake resulting from both central and peripheral adaptations decreased minute ventilation at a given absolute submaximal intensity decreased myocardial oxygen cost for a given absolute submaximal intensity decreased heart rate and blood pressure at a given submaximal intensity increased capillary density in skeletal muscle increased exercise threshold for the accumulation of lactate in the blood increased exercise threshold for the onset of disease signs or symptoms ( e.g. -, angina pectoris, ischemic st-segment depression, claudication) reduction in cardiovascular disease risk factors reduced resting systolic/diastolic pressure increased serum high-density lipoprotein cholesterol and decreased serum triglycerides reduced total body fat, reduced intra-abdominal fat reduced insulin needs, improved glucose tolerance reduced blood platelet adhesiveness and aggregation reduced inflammation decreased morbidity and mortality primary prevention ( i.e. -, interventions to prevent the initial occurrence) higher activity and/or fitness levels are associated with lower death rates from cad higher activity and/or fitness levels are associated with lower incidence rates for cvd, cad, stroke, type 2 diabetes mellitus, metabolic syndrome, osteo- porotic fractures, cancer of the colon and breast, and gallbladder disease secondary prevention ( i.e. -, interventions after a cardiac event to prevent another) based on meta-analyses ( i.e. -, pooled data across studies), cardiovascular and all-cause mortality are reduced in patients with post-myocardial infarc- tion (mi) who participate in cardiac rehabilitation exercise training, especially as a component of multifactorial risk factor reduction (note: randomized controlled trials of cardiac rehabilitation exercise training involving patients with post-mi do not support a reduction in the rate of nonfatal reinfarction). -other benefits decreased anxiety and depression improved cognitive function enhanced physical function and independent living in older individuals enhanced feelings of well-being enhanced performance of work, recreational, and sport activities reduced risk of falls and injuries from falls in older individuals prevention or mitigation of functional limitations in older adults effective therapy for many chronic diseases in older adults cad, coronary artery disease; cvd, cardiovascular disease. -adapted from ( 45 , 70 , 94 ). -10 guidelines for exercise testing (cid:129) www.acsm.org preliminary work suggests that resistance exercise may prevent and improve depression and anxiety, increase vigor, and reduce fatigue ( 26 , 86 ). -risks associated with physical activity and exercise although the bene ts of regular pa are well established, participation in exercise is associated with an increased risk for musculoskeletal injury (msi) and cardiovas- cular complications ( 26 ). -msi is the most common exercise-related complication and is oft en associated with exercise intensity, the nature of the activity, preexisting conditions, and musculoskeletal anomalies. -adverse cardiovascular events such as sudden cardiac death (scd) and acute myocardial infarction (ami) are usually associated with vigorous intensity exercise ( 3 , 66 , 93 ). -scd and ami are much less common than msi but may lead to long-term morbidity and mortality ( 4 ). -exercise-related musculoskeletal injury participation in exercise and pa increases the risk of msi ( 68 , 76 ). -th e intensity and type of exercise may be the most important factors related to the incidence of injury ( 26 ). -walking and moderate intensity physical activities are associated with a very low risk of msi, whereas jogging, running, and competitive sports are associated with an increased risk of injury ( 26 , 39 , 40 ). -th e risk of msi is higher in activities where there is direct contact between participants or with the ground ( e.g. -, football, wrestling) versus activities where the contact between participants or with the ground is minimal or nonexistent ( i.e ., baseball, running, walking) ( 38 , 76 ). -in 2012, over 6 million americans received medical attention for sport-related injuries, with the highest rates found in children between the ages of 12 and 17 yr (91.34 injury episodes per 1,000 population) and children younger than the age of 12 yr (20.03 injury episodes per 1,000 population) ( 1 ). -th e most common anatomical sites for msi are the lower extremities with higher rates in the knees followed by the foot and ankle ( 39 , 40 ). -th e literature on injury consequences of pa participation oft en focuses on men from nonrepresentative populations ( e.g. -, military personnel, athletes) ( 43 ). -a prospective study of community-dwelling women found that meeting the national guidelines of (cid:2)150 min (cid:2) wk (cid:4)1 of moderate-to-vigorous intensity pa resulted in a modest increase in pa-related msi compared to women not meeting the pa guidelines ( 68 ). -however, the risk for developing msi is inversely related to physical tness level ( 76 ). -for any given dose of pa, individuals who are physically inactive are more likely to experience msi when compared to their more active counterparts ( 76 ). -commonly used methods to reduce msi ( e.g. -, stretching, warm-up, cool-down, and gradual progression of exercise intensity and volume) may be helpful in some situations; however, there is a lack of controlled studies con rming the e ective- ness of these methods ( 26 ). -a comprehensive list of strategies that may prevent msi can be found elsewhere ( 12 , 28 ). -chapter 1 bene ts and risks associated with physical activity 11 sudden cardiac death among young individuals th e cardiovascular causes of exercise-related sudden death in young athletes are shown in table 1.3 ( 4 ). -it is clear from these data that the most common causes of scd in young individuals are congenital and hereditary abnormalities including table 1.3 cardiovascular causes of exercise-related sudden death in young athletesa van camp et al. -(n (cid:4) 100)b (95) maron et al. -(n (cid:4) 134) (60) corrado et al. -(n (cid:4) 55)c (18) hypertrophic cm probable hypertrophic cm coronary anomalies valvular and subvalvular aortic stenosis possible myocarditis dilated and nonspeci c cm atherosclerotic cvd aortic dissection/rupture arrhythmogenic right ventricular cm myocardial scarring mitral valve prolapse other congenital abnormalities long qt syndrome wolff-parkinson-white syndrome cardiac conduction disease cardiac sarcoidosis coronary artery aneurysm normal heart at necropsy pulmonary thromboembolism 51 5 18 8 7 7 3 2 1 0 1 0 0 1 0 0 1 7 0 36 10 23 4 3 3 2 5 3 3 2 1.5 0.5 0 0 0.5 0 2 0 1 0 9 0 5 1 10 1 11 0 6 0 0 1 3 0 0 1 1 a ages ranged from 13 to 24 yr ( 95 ), 12 to 40 yr ( 60 ), and 12 to 35 yr ( 18 ). -references ( 95 ) and ( 60 ) used the same database and include many of the same athletes. -all ( 95 ), 90% ( 60 ), and 89% ( 18 ) had symptom onset during or within an hour of training or competition. -b total exceeds 100% because several athletes had multiple abnormalities. -c includes some athletes whose deaths were not associated with recent exertion. -includes aberrant artery origin and course, tunneled arteries, and other abnormalities. -cm, cardiomyopathy; cvd, cardiovascular disease. -used with permission from ( 4 ). -12 guidelines for exercise testing (cid:129) www.acsm.org hypertrophic cardiomyopathy, coronary artery abnormalities, and aortic stenosis. -th e absolute annual risk of exercise-related death among high school and college athletes is 1 per 133,000 men and 769,000 women ( 95 ). -it should be noted that these rates, although low, include all sports-related nontraumatic deaths. -of the 136 total identi able causes of death, 100 were caused by cvd. -a more recent estimate places the annual incidence of cardiovascular deaths among young competitive athletes in the united states as 1 death per 185,000 men and 1.5 million women. -( 58 ). -some experts, however, believe the incidence of exercise-related sudden death in young sports participants is higher, ranging between 1 per 40,000 and 1 per 80,000 athletes per year ( 32 ). -furthermore, death rates seem to be higher in african american male athletes and basketball players ( 32 , 59 ). -experts debate on why estimates of the in- cidence of exercise-related sudden deaths vary among studies. -th ese variances are likely due to di erences in (a) the populations studied, (b) estimation of the number of sport participants, and (c) subject and/or incident case assignment. -in an e ort to reduce the risk of scd incidence in young individuals, well-recognized organi- zations such as the international olympic committee and aha have endorsed the practice of preparticipation cardiovascular screening ( 19 , 53 , 61 ). -th e recent position stand by the american medical society for sports medicine presents the latest evi- dence based research on cardiovascular preparticipation screening in athletes ( 23 ). -exercise-related cardiac events in adults in general, exercise does not provoke cardiovascular events in healthy individu- als with normal cardiovascular systems. -th e risk of scd and ami is very low in apparently healthy individuals performing moderate intensity pa ( 76 , 101 ). -th ere is an acute and transient increase in the risk of scd and ami in individuals per- forming vigorous intensity exercise, particularly in sedentary men and women with diagnosed or occult cvd ( 3 , 4 , 29 , 66 , 85 , 90 , 105 ). -however, this risk decreases with increasing volumes of regular exercise ( 89 ). -chapter 2 includes an exercise preparticipation health screening algorithm to help identify individuals who may be at risk for exercise-related cardiovascular events. -it is well established that the transient risks of scd and ami are substan- tially higher during acute vigorous physical exertion as compared with rest ( 29 , 66 , 85 , 91 , 105 ). -a recent meta-analysis reported a vefold increased risk of scd and 3.5-fold increased risk of ami during or shortly aft er vigorous intensity pa ( 20 ). -th e risk of scd or ami is higher in middle-aged and older adults than in younger individuals due to the higher prevalence of cvd in the older population. -th e rates of scd and ami are disproportionately higher in the most sedentary individu- als when they perform unaccustomed or infrequent exercise ( 4 ). -for example, the onset study ( 65 ) showed that the risk of ami during or immediately following vig- orous intensity exercise was 50 times higher for the habitually sedentary compared to individuals who exercised vigorously for 1-h sessions (cid:2)5 d (cid:2) wk (cid:4)1 ( figure 1.2 ). -although the relative risks of scd and ami are higher during sudden vig- orous physical exertion versus rest, the absolute risk of these events is very low. -chapter 1 bene ts and risks associated with physical activity 13 i m a f o k s i r e v i t a l e r 200 100 50 30 10 8 4 2 1 0.5 0 * active subject sedentary subject *vigorous exercise bout * * * baseline risk 0 1-2 3-4 5+ (days/week) habitual frequency of vigorous physical activity figure 1.2 the relationship between habitual frequency of vigorous physical activity and the relative risk of acute myocardial infarction (ami). -used with permission from ( 24 ). -prospective evidence from the physicians health study and nurses health study suggests that scd occurs every 1.5 million episodes of vigorous physical exertion in men ( 3 ) and every 36.5 million h of moderate-to-vigorous exertion in women ( 101 ). -retrospective analyses also support the rarity of these events. -th ompson et al. -( 90 ) reported 1 death per 396,000 h of jogging. -an analysis of exercise-related cardiovascular events among participants at ymca sports centers found 1 death per 2,897,057 person-hours, although exercise intensity was not documented ( 55 ). -kim et al. -( 46 ) studied over 10 million marathon and half-marathon runners and identi ed an overall cardiac arrest incidence rate of 1 per 184,000 runners and an scd incidence rate of 1 per 256,000 runners, which translates to 0.20 cardiac arrests and 0.14 scds per 100,000 estimated runner-hours. -although the risk is extremely low, vigorous intensity exercise has a small but measurable acute risk of cvd complications; therefore, mitigating this risk in sus- ceptible individuals is important (see chapter 2 ). -th e exact mechanism of scd during vigorous intensity exercise with asymptomatic adults is not completely understood. -however, evidence exists that the increased frequency of cardiac con- traction and excursion of the coronary arteries produces bending and exing of the coronary arteries may be the underlying cause. -th is response may cause crack- ing of the atherosclerotic plaque with resulting platelet aggregation and possible acute thrombosis and has been documented angiographically in individuals with exercise-induced cardiac events ( 9 , 16 , 31 ). -14 guidelines for exercise testing (cid:129) www.acsm.org exercise testing and the risk of cardiac events as with vigorous intensity exercise, the risk of cardiac events during exercise test- ing varies directly with the prevalence of diagnosed or occult cvd in the study population. -several studies have documented these risks during exercise testing ( 7 , 27 , 41 , 48 , 64 , 78 , 87 ). -table 1.4 summarizes the risks of various cardiac events in- cluding ami, ventricular fi brillation, hospitalization, and death. -th ese data indi- cate in a mixed population the risk of exercise testing is low with approximately six cardiac events per 10,000 tests. -one of these studies includes data for which the exercise testing was supervised by nonphysicians ( 48 ). -in addition, the majority of these studies used symptom-limited maximal exercise tests. -th erefore, it would be expected that the risk of submaximal testing in a similar population would be lower. -table 1.4 cardiac complications during exercise testinga reference year site rochmis and blackburn (78) 1971 73 u.s. centers no. -of tests mi vf death hospitalization comment 170,000 na na 1 3 34% of tests were symptom limited; 50% of deaths in 8 h; 50% over the next 4 d vf includes other dysrhyth- mias requiring treatment. -only 4% of men and 2% of women had cvd. -irving et al. -(41) 1977 15 seattle facilities 10,700 na 4.67 1977 hospital 12,000 0 0 0 0 1979 20 swedish 50,000 0.8 0.8 0.4 centers 1980 1,375 u.s. 518,448 3.58 4.78 0.5 centers mchenry (64) atterh g et al. -(7) stuart and ellestad (87) nr 0 5.2 nr gibbons et al. -(27) 1989 cooper clinic 71,914 0.56 0.29 0 nr knight et al. -1995 geisinger 28,133 1.42 1.77 0 nr 25% were (48) cardiology service inpatient tests supervised by non-mds. -a events are per 10,000 tests. -cvd, cardiovascular disease; md, medical doctor; mi, myocardial infarction; na, not applicable; nr, not reported; vf, ventricular brillation. -chapter 1 bene ts and risks associated with physical activity 15 table 1.5 summary of contemporary exercise-based cardiac rehabilitation program complication rates investigator year patient exercise hours cardiac arrest myocardial infarction fatal events major complicationsa van camp and peterson (96) 1980 1984 2,351,916 1/111,996b 1/293,990 1/783,972 1/81,101 digenio et al. -(21) 1982 1988 vongvanich et al. -1986 1995 480,000 1/120,000c 268,503 1/89,501d 1/160,000 1/120,000 1/268,503d 0/268,503 1/67,126 (98) franklin et al. -(25) 1982 1998 292,254 1/146,127d 1/97,418d 0/292,254 1/58,451 average 1/116,906 1/219,970 1/752,365 1/81,670 a myocardial infarction and cardiac arrest. -b fatal 14%. -c fatal 75%. -d fatal 0%. -used with permission from ( 4 ). -risks of cardiac events during cardiac rehabilitation th e highest risk of cardiovascular events occurs in those individuals with di- agnosed cad. -in one survey, there was one nonfatal complication per 34,673 h and one fatal cardiovascular complication per 116,402 h of cardiac rehabilita- tion ( 33 ). -other studies have found a lower rate: one cardiac arrest per 116,906 patient-hours, one ami per 219,970 patient-hours, one fatality per 752,365 pa- tient-hours, and one major complication per 81,670 patient-hours ( 21 , 25 , 96 , 98 ). -th ese studies are presented in table 1.5 ( 4 ). -a more recent study demonstrated an even lower rate of cardiovascular complications during cardiac rehabilitation with one cardiac arrest per 169,344 patient-hours, no ami per 338,638 patient-hours, and one fatality per 338,638 patient-hours ( 81 ). -although these complication rates are low, it should be noted that patients were screened and exercised in medically supervised settings equipped to handle cardiac emergencies. -th e mortality rate appears to be six times higher when patients exercised in facilities without the ability to successfully manage cardiac arrest ( 4 , 21 , 25 , 96 , 98 ). -interestingly, how- ever, a review of home-based cardiac rehabilitation programs found no increase in cardiovascular complications versus formal center-based exercise programs ( 100 ). -prevention of exercise-related cardiac events because of the low incidence of cardiac events related to vigorous intensity exercise, it is very di cult to test the e ectiveness of strategies to reduce the occurrence of 16 guidelines for exercise testing (cid:129) www.acsm.org these events. -according to a recent statement by the acsm and aha ( 4 ), physi- cians should not overestimate the risks of exercise because the bene ts of habitual physical activity substantially outweigh the risks. -th is report also recommends sev- eral strategies to reduce these cardiac events during vigorous intensity exercise ( 4 ): health care professionals should know the pathologic conditions associated with exercise-related events so that physically active children and adults can be appropriately evaluated. -physically active individuals should know the nature of cardiac prodromal symptoms ( e.g. -, excessive, unusual fatigue and pain in the chest and/or upper back) and seek prompt medical care if such symptoms develop (see table 2.1 ). -high school and college athletes should undergo preparticipation screening by quali ed professionals. -athletes with known cardiac conditions or a family history should be evaluated prior to competition using established guidelines. -health care facilities should ensure their sta is trained in managing cardiac emergencies and have a speci ed plan and appropriate resuscitation equipment (see appendix b ). -physically active individuals should modify their exercise program in response to variations in their exercise capacity, habitual activity level, and the environ- ment (see chapters 6 and 8 ). -although strategies for reducing the number of cardiovascular events during vigorous intensity exercise have not been systematically studied, it is incumbent on the exercise professional to take reasonable precautions when working with individuals who wish to become more physically active/ t and/or increase their pa/ tness levels. -th ese precautions are particularly true when the exercise pro- gram will be of vigorous intensity. -although many sedentary individuals can safely begin a light-to-moderate intensity exercise program, all individuals should par- ticipate in the exercise preparticipation screening process to determine the need for medical clearance (see chapter 2 ). -exercise professionals who supervise exercise and tness programs should have current training in basic and/or advanced cardiac life support and emer- gency procedures. -th ese emergency procedures should be reviewed and practiced at regular intervals (see appendix b ). -finally, individuals should be educated on the signs and symptoms of cvd and should be referred to a physician for further evaluation should these symptoms occur. -o n l i n e r e s o u r c e s american college of sports medicine position stand on the quantity and quality of exercise: http://www.acsm.org 2008 physical activity guidelines for americans: http://www.health.gov/paguidelines chapter 1 bene ts and 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15 ): 1383 5 . -wang cy , haskell wl , farrell sw , et al. -cardiorespiratory tness levels among us adults 20-49 years of age: ndings from the 1999-2004 national health and nutrition examination survey . -am j epidemiol . -2010 ; 171 ( 4 ): 426 35 . -wenger nk , froelicher es , smith lk , et al. -cardiac rehabilitation as secondary prevention . -agency for health care policy and research and national heart, lung, and blood institute . -clin pract guidel quick ref guide clin . -1995 ;( 17 ): 1 23 . -whang w , manson je , hu fb , et al. -physical exertion, exercise, and sudden cardiac death in women . -jama . -2006 ; 295 ( 12 ): 1399 403 . -williams ma , haskell wl , ades pa , et al. -resistance exercise in individuals with and without cardiovascular disease: 2007 update: a scienti c statement from the american heart associa- tion council on clinical cardiology and council on nutrition, physical activity, and metabo- lism . -circulation . -2007 ; 116 ( 5 ): 572 84 . -williams pt . -dose-response relationship of physical activity to premature and total all-cause and cardiovascular disease mortality in walkers . -plos one . -2013 ; 8 ( 11 ): e78777 . -williams pt . -physical tness and activity as separate heart disease risk factors: a meta-analysis . -med sci sports exerc . -2001 ; 33 ( 5 ): 754 61 . -willich sn , lewis m , l wel h , arntz hr , schubert f , schr der r . -physical exertion as a trig- ger of acute myocardial infarction . -triggers and mechanisms of myocardial infarction study group . -n engl j med . -1993 ; 329 ( 23 ): 1684 90 . -yang z , scott ca , mao c , tang j , farmer aj . -resistance exercise versus aerobic exercise for type 2 diabetes: a systematic review and meta-analysis . -sports med . -2014 ; 44 ( 4 ): 487 99 . -yu s , yarnell jw , sweetnam pm , murray l . -what level of physical activity protects against premature cardiovascular death? -th e caerphilly study . -heart . -2003 ; 89 ( 5 ): 502 6 . - - -Book 2: - -the introduction to yoga philosophy alone is worth the price of the book. -anyone wishing to know the techniques of yoga from a master should study this book." --astral p r ojection "600 pictures and an incredible amount of detailed descriptive text as well as philosophy .... fully revised and photographs illustrating the exercises appear right next to the descriptions (in the earlier edition the photographs were appended). -we highly recommend this book." --well ness light on yoga 50 years of publishing 1945-1995 yoga dipika b. k. s. iyengar foreword by yehudi menuhin revised edition schocken books new 1:'0rk by schocken books 1966 first published revised edition published paperback revised edition published copyright 1966, 1968, 1976 by george allen & unwin (publishers) by schocken books 1979 by schocken books 1977 ltd. all rights reserved conventions. -published new york. -distributed house, inc., new york. -under international and pan-american copyright in the united states by schocken books inc., by pantheon books, a division of random library of congress cataloging data in publication iyengar, b.k.s. -1918- light on yoga. -1. yoga, hatha. -i. title. -ra 781.7.194 1977 613.7 76-48857 isbn 0-8052-1031-8 manufactured c987654321 in the united states of america dedicated to my revered guruji ' samkya-yoga- nyayacharya> sikhamar;i mimamsa-ratna> mimamsa-thrrtha >. -veda-kesari >. -vedantavag'isa >. -professor, sriman, t. krishnamacharya of mysore (south india), india . -, pray.er 'i bow before the noble t: who brought serenity of speech by his work on grammar and purity of body by his work on medicine., of sages, patanjali, of mind by his work on yoga, clarity 'i salute adfsvara (the primeval lord siva) who taught first the science of ha!ha yoga-a science that stands out as a ladder for those who wish to scale the heights of raja yoga., i foreword by yehudi menuhin of yoga induces a primary sense of measure and proportion. -the practice reduced to our own body, our first instrument, drawing from it maximum resonance patience attack, frustration we refine and animate and liberating unlocking and death. -and harmony. -with unflagging every cell as we return daily to the capacities otherwise condemned to we learn to play it, each unfulfilled area of tissue and nerve, of brain or lung, is a or otherwise or of wimessing the precision, to our will and integrity, of frustratkm mr i yen gar's a source of receiving refinement and beauty of his to that vision of perfection and innocence which is challenge and death. -whoever has had the privilege attention, art, is introduced man as first created-unarmed, unashamed, -in the garden of eden. -the tree of knowledge fruit of great variety, bitter, our use of it. -but is it not more imperative the tree, that we nourish its roots? -and furthermore how dangerous would rather that knowledge apply it to the manipulation improvement has indeed wholesome according than ever that we cultivate to those who, ill at ease with themselves, of other people and things than to the son of god, lord of creation of their own persons. -sweet, poisonous, much to yielded is the practice of yoga over the past fifteen years has convinced to life have their physical me that counterparts must begin with the align to a degree at which even finer of will will cause us to start by the top of the head in defiance of and might begin with the sense of weight attitudes and ambition and criticism and right sides are feasible: or strength the body from the toes to most of our fundamental in the body. -thus comparison ment of our own left adjustments stretching gravity. -impetus speed that comes with free-swinging of prolonged is gained by stretching while calmness comes with quiet, consistent sion of the lungs. -the knowledge eternal cycle, wave or vibration umverse. -continuity of the inevitable rhythms of which each inhalation alternation among the countless and a sense of the universal of tension and breathing and the expan come with relaxation constitutes in one myriads which are the and exhalation balance on foot, feet or hands, which gives poise. -limbs, instead of with the control tenacity in various yoga postures for minutes at a time, 12 foreword coronary cripples thwarted, criticisin attitudes, g the upright, what is the alternative? -the warped people condemning autocrats slumped in of people working out the tragic spectacle order of things, expectant their own imbalance yoga, as practised a man who brings himself focussed in attention and will, offering in simplicity a burnt sacrifice, but simply himself raised to his own highest potential. -is the dedicated alone and clean in body and mind, not and innocence and frustration on others. -by mr iyengar, to the altar, votive offering of it is a technique ideally suited to prevent physical and mental illness and to protect reliance with universal pensable and firmness the body generally, developing an inevitable sense of self and assurance. -by its very nature it is laws: for respect for life, truth, and patience inextricably are all associated indis factors in the drawing of a quiet breath, in calmness of mind of will. -in this lie the moral virtues inherent in yoga. -for these reasons it and forming the whole demands a complete and total effort, involving human being. -no mechanical as in the case of good resolutions it is each time and every moment is involved or formal prayers. -a living act. -repetition and no lip-service by its very nature mr iyengar's light on yoga will, i hope, enable many to follow his example and to become the teachers if this book practised at having shared in its presentation. -will serve to spread this basic art and will ensure that it is grateful for the highest level, i shall feel more than ever whom mankind so sorely needs. -preface it is only thanks to the persistent and pupils that this repeatedly english language but because i would have buoyant support not only because of and assurance. -faltered book is now achieved-for alone i would have command of the my inadequate encouragement of my devoted friends their lost heart without yoga is a timeless pragmatic science evolved over thousands with the physical, moral, mental and spiritual of years of man well-being dealing as a whole. -was the classic treatise this practice of patafljali the first book to systematise most of the books published the dating from 200 bc. -u nfor on yoga in our day have been as they are asked by yoga sutras (or aphorisms) tunately unworthy of both the subject superficial, their readers whether i can drink acid, chew glass, walk through fire, make myself invisible or perform other magical acts. -scholarly expositions reliable in most languages-but the practice municate than a purely literary and texts already of an art is more difficult to com popular and at times misleading. -and its first great exponent, of the religious and or philosophical philosophical i have even been concept. -exist the title of this book is light on yoga (yoga di'pika in sanskrit), as the asanas (postures) (breathing as simply as possible disciplines) and its requirements. -given in great detail and are based on my purpose is to describe and pranayamas its knowledge are therefore over twenty-seven complete asanas can be mastered : and it also covers bandha, kriya and pranayama with a further 5 photographs. -for years in many parts of the world. -it contains the of zoo asanas with 592 photographs from which the in the new light of our own era, on asana and pranayama my experience instructions technique the western reader may be surprised to at the recurring and even to philosophical reference and moral spirit, to mythology he must not forget that in ancient times all the higher the universal principles. -of man, in knowledge, art achievements and were assumed to belong to god and to his priestly earth. -the catholic ledge and power in the west. -but formerly, even in the western world, as wars, music, painting, on of divine know pope is the last such embodiment and power, were part of religion servants architecture, philosophy and medicine, as well 14 preface of god. -it is only very recently have begun to be emancipated in india that from the divine for the emancipation of man's from will, as distinct sciences were always in the service these arts and but with due respect, the divine will, we in india continue the humility long bondage to god. -i consider the reader should legends included ancient commentaries all the direction know the origin of asanas, handed down by practising of discipline and the selflessness on yoga have stressed of a guru (master), it important to value the purity of purpose, that are the legacy of our as well as interesting that yogis and sages. -and i have, therefore, to work under the experience humility a correct proves the wisdom of this rule, i have endeavoured in this book to guide the reader- and safe method of mastering these both teacher asanas and prai].ayamas. -that it is essential my and although with all and student-to in appendix i , i have introduced the asanas stage by a 300 weeks' course for the intense to their stage according grouping practitioner, structure. -in appendix and curative value. -i i, i have arranged groups of asanas for their therapeutic study in detail the hints and cautions before attempting the asana and pranayama techniques. -i am sincerely grateful to my esteemed friend and pupil mr yehudi menuhin for his foreword and immeasurable support. -i am indebted to my pupil mr b. i . -taraporewala for his collabora tion in the preparation of this book. -i thank messrs allen and unwin for their gesture in publishing this exhaustively public, and eilean pearcey for providing the drawings. -illustrated book and presenting my work to a world-wide i express my sincere to messrs g. g. welling of poona for their personal (india), photographs disposal. -for me and for placing gratitude supervision and interest the resources in taking innumerable of their studio at my the author wishes to express his gratitude the care with which he dealt with the editing subsequent proof correction. -to mr gerald yorke for and of the typescript b. k. s. iyengar contents foreword by yehudi menuhin preface page i i 13 part i i n t r o d u c t i o n what is yoga? -17 19 part ii yogasanas, bandha and kriya 55 57 yogasanas 57 bandha and kriya part iii pranayama hints and cautions technique and effects of pra ayama pra ayamas appendix/: asana courses 429 431 441 449 appendix ii: curative asanas for various diseases table to correlate the asanas etc. -with the plates which illustrate them glossary index 537 part i introduction what is yoga? -the word yoga is derived from the sanskrit join, attach and yoke, to direct and concentrate use and apply. -it also means union or communion. -of our will with the will of god. -'it thus means,' says mahadev in his introduction the powers the intellect, supposes; in all its aspects of the will, which that yoga l?re it means a poise of the soul which enables one to look at life root yuj meaning to bind, on, to one's attention union it is the true desai to gandhi, 'the yoking of all of body, mind and soul to god; it means the disciplining the mind, the emotions, to the gita according evenly.' -co-ordinated it was yoga is one of the six orthodox systems of indian philosophy. -in his classical and systematised in indian which consists collated, work, the yoga sutras, thought, everything (paramatma or god) part. -the system of yoga is so called because it teaches the means by which the j1vatma can be united to, or be in paramatma, is permeated by the supreme universal is a of which by pataiijihi of 185 terse aphorisms. -and so secure liberation communion with the the individual human spirit (j1vatma) (mok a). -spirit one who follows the path of yoga is a yogi or yogin. -in the sixth chapter of the bhagavad gita, which is sri krishna explains on yoga philosophy, authority ing of yoga as a deliverance from contact with to arjuna the mean pain and sorrow. -it is said: the most important freed desire, within, are under control, a man becomes so that they rest in the spirit and self (aharilkara) and self, being absorbed in the spirit within him. -when the and self 'when his mind, intellect from restless a yukta-one in communion with god. -a lamp does not flicker place where no winds blow; so it is with a yogi, who controls his intellect restlessness of the mind, intellect of yoga, the yogi by the grace ment. -then he knows the joy eternal which is beyond the pale of senses which his reason cannot grasp. -he abides in this reality he has found the treasure not therefrom. -nothing higher than this. -he who has achieved the greatest from contact with pain and sorrow.' -of the spirit within himself finds fulfil the and moves above all others. -there is it, shall not be moved by meaning of yoga- a deliverance sorrow. -this is the real in a mind, through the is stilled practice 20 light on yoga as a well cut diamond has many facets, each reflecting colour of light, so does the word yoga, each facet reflecting shade of meaning and revealing human endeavour to win inner peace and happiness. -different aspects of the entire range of a different a different the bhagavad gztii also gives other explanations of the term yoga and lays stress upon karma yoga (yoga by action). -it is said: is your privilege, never the be your motive; and abandoning equipoise never cease to work. -work in the name of the lord, this be not affected by success or failure. -never let the fruits of action selfish desires. -fruits thereof. -is called yoga.' -'work alone yoga has also been described as wisdom in work or skilful living harmony and moderation. -amongst activities, 'yoga is not for him who gorges too much, himself. -awake. -by moderation and by concordance sorrow.' -in sleeping it is not for him who sleeps too much, nor for him who stays in working in eating and in resting, by regulation and waking, yoga destroys all pain and nor for him who starves the kathopanishad describes yoga thus: 'when the senses are stilled, when the mind is at rest, when the intellect highest wise, is reached the mind has been defined as yoga. -he who attains stage. -this steady wavers not-then, say the and control of the senses it is free from delusion.' -in the second aphorism of the first chapter of the yoga sutras, describes (nirodhah) v tti nirodhah'. -of mental (chitta) of the fluctuations the word chitta denotes trans this may be (v tti) modifications yoga as 'chitta (nirodhah) patafi.jali lated as the restraint or as suppression (chitta). -as being composed of three categories: (a) mind (manas, that is, the and individual rejection; ligence the distinction between 1-maker, mind having the it is the oscillating (buddhi, power and faculty indecisive selection of the mind); (b) intel state which determines the mind in its total or that is, the decisive of attention, that 'i know'). -sense collective or reason (vrtti) faculty the state which ascertains the word v tti is derived from the sanskrit root v t meaning to turn, of consciousness things) and (c) ego (aharilkara, literally the to roll on. -it thus means course of action, mode behaviour, state. -yoga is the method by which the mind is calmed and the energy directed when properly of water, prevents harnessed into constructive by dams famine and pro or mental to revolve, of being, condition restless channels. -and canals, vides abundant power for industry; provides uplift. -as a mighty river which a vast reservoir a reservoir creates of peace and generates so also the mind, when controlled, abundant energy for human the problem of controlling as borne out by the follow ng bhagavad gfta. -arjuna asks sri krishna: the mind is not capable of easy solution, dialogue in the sixth chapter of the lntroduct on 21 you have told me of yoga as a communion with brahman (the spirit), which is ever one. -but how can this be permanent, and inconsistent? -the mind is impetuo s mind is so restless 'krishna, universal since the and stubborn, strong and wilful, krishna replies: 'undoubtedly, but it can be trained by constant from desire (vairagya). -difficult to attain this can attain it if he tries divine communion; hard and directs as difficult to harness as the wind.' -sri the mind is restless practice a man who cannot control his (abhyasa) and hard to control. -and by freedom mind will find it lled man but the self-contro his energy by the right means.' -the stages of yoga these means as the eight limbs or stages of yoga for the as the end in view. -pataiijali the right means are just as enumerates quest of the soul. -they are: i. yama (universal important !.lloral commandments); 2. niyama (self purifica ; 3 asana (posture); 4 prat:j.ayama (rhythmic control (withdrawal of the senses and exterior and emancipation of the mind 6. dharat:j.a objects); 5 pratyahara tion by discipline) of the breath); from the domination (concentra super-consciousness the individual meditation- aspirant tion); 7 dhyana (meditatio n) and 8. samadhi (a state of brought about by profound meditation, in which becomes one with the object of his (sadhaka) paramatma or the universal spirit). -yama and niyama control the yogi's passions him in harmony with his fellow man. -asanas keep the strong and in harmony with nature. -finally, body consciousness. -for the soul. -the first three stages are the outward quests (bahiranga sadhana). -h e conquers the body and renders it a fit vehicle and emotions and keep body healthy and the yogi becomes free of the next two stages, prat:j.ayama and pracyahara, the breathing, and to regulate free the senses from the thraldom of the objects stages of yoga are known as the inner quests thereby control the mind. -(antaranga of desire. -sadhana). -these two dharana, dhyana and samadhi take the yogi into the innermost of his soul. -the yogi does not look heavenward to find god. -teach the aspirant this helps to recesses he knows that he is within, self). -maker. -these stages are soul. -the last three stages keep him in harmony with himself and his sadhana, the quest of the called antaratma being known as the antaratma (the inner 22 light on yoga by profound meditation, the knower, the knowledge and the known existence it is like a great musician becoming one with his no separate become one. -the seer, the sight and the seen have from each other. -instrument in his own nature and realises himself. -soul within and the music that comes from it. -then, the yogi stands his self (atman), the part of the supreme his own divinity there are different paths (margas) by which a man travels man finds realisation man finds it through bhakti marga, where there maker. -the active which a man realises emotional tion through devotion to man pursues jiiana marga, where realisation comes follows yoga marga, and the meditative own divinity through karma marga, in the through work and duty. -is realisa and love of a personal or reflective man through control of the mind. -realises to his through knowledge. -his god. -the intellectual the real from the and the good from the pleasant is he who knows true love by happy is the man who knows how to distinguish from the transient and wisdom. -twice blessed unreal, the eternal his discrimination and can love all god's creatures. -of others with love in his heart is thrice blessed. -knowledge, combines within his mortal frame is holy and becomes a place of pilgrimage, rivers ganga, saraswati calm and purified. -and jam una. -those who meet him become love and selfless like the confluence service of the he who works selflessly for the welfare but the man who mind is the king of the senses. -one who has conquered his mind, senses, passions, raja yoga, the royal union with the universal light. -thought and reason is a king among men. -he is fit for spirit. -he has inner he who has conquered a king. -the expression self. -though pataiiiali where states in his aphorisms a ailga mastery of the self one may call it the science yoga or the eight stages (limbs) his mind is a raja yogi. -the word raja means raja yoga implies a complete mastery of the explains the ways to control the mind, he no that this science is raja yoga, but calls it of yoga. -as it implies of raja yoga. -complete swatmarama, the author of the hatha yoga pradzpika effort) called the same path hatha yoga because it (hatha =force or determined demanded rigorous it is generally discipline. -believed that raja yoga and ha ha yoga are entirely deal with spiritual different and opposed distinct, pataiijali pradfpika of swatmarama deals solely with physical so, for ha ha yoga and raja yoga complement single approach towards liberation. -ropes and crampons as well as physical to each other, that discipline the yoga sutras of and that the hatha yoga it is not discipline. -to climb fitness and discipline as a mountaineer each other and form a needs ladders, peaks of the himalayas, the icy ledge and discipline heights of raja yoga dealt with by pataiijali. -so does the of the ha ha yoga of swatmarama to reach the yoga aspirant need the know introduction 23 this path of yoga is the fountain and tranquillity and prepares calmness self-surrender for the other three paths. -it brings the mind for absolute unqualified to god, in which all these four paths merge into one. -chitta v tti (causesfor the modification of the mind) in his yoga sutras pataiijali pleasure and pain. -these are: lists five classes of chitta vrtti which create or ideal), (a standard 1. pramax:ta by the mind or known, which men accept upon (a) direct evidence as perception the word of an acceptable been checked as reliable such or when the source of knowledge has (b) inference authority by which things or values are measured and trustworthy (anumana) and (pratyak a), (c) testimony (agama). -(a mistaken 2. viparyaya a faulty held theory in astronomy examples of viparyaya. -medical diagnosis view which is observed based on wrong hypotheses, that the sun rotates round the to be such after study). -or the formerly earth, are 3 vikalpa (fancy or imagination, without any factual himself spending millions. -himself in the belief that he is poor. -basis). -resting merely on verbal expression a beggar may feel happy when a rich miser, on the other hand, may starve he imagines where there is the absence of ideas and experiences. -4 nidra (sleep), when a man is sleeping soundly, status, his knowledge forgets himself in sleep, he wakes up refreshed. -thought creeps into his mind when he properly. -he does not recall or wisdom, or even his own existence. -when a man but, if a disturbing is dropping off, he will not rest his name, family or 5 smrti (memory, the holding fast of the impressions one has experienced). -ences, even though memories keep fetters. -them chained to the past and they the past is beyond recall. -there are people who live in their past experi their sad or happy cannot break their of objects that pataiijali enumerates five causes of chitta vrtti creating pain (klesa). -these are: 1. avidya (ignorance duality which which may be physical, limits a person and distinguishes mental, intellectual him from a group and or emotional); (3) raga or nescience); (2) asmita (the feeling of indivi 24 light on yoga or passion); (4) dve8a (aversion (love of or thirst for life, the instinctive or revulsion) clinging and (5) to worldly from all and the fear that one may be cut off (attachment abhinivesa life and bodily enjoyment this by death). -the sadhaka (the aspirant ing their heads in the polar seas. -so long as they are not studiously controlled can be no peace. -the yogi learns to forget the past and takes no thought for the morrow. -he lives in the eternal these causes of pain remain submerged in the mind of barely show and eradicated, there they are like icebergs or seeker). -present. -as a breeze ruffles the surface of a lake and therein, reflected the still waters of is still, the beauty mind by constant stages of yoga teach him the way. -the images so also the chitta v tti disturb the peace of the mind. -a lake reflect of the self is seen reflected study and by freeing himself from desires. -the beauty around it. -when the mind his in it. -the yogi stills distorts the eight chitta vik epa (distractions and obstacles) the distractions yoga are: and obstacles which hinder the aspirant's practice of the physical which disturbs i. vyadhi-sickness equilibrium 2. styana -languor or lack of mental disposition for work 3 sarilsaya-doubt or indecision 4 pramada-indifference 5 . -alasya -laziness 6. a virati-sensuality, the rousing of desire when sensory or insensibility objects possess the mind 1 bhranti darsana- false or invalid 8. alabdha bhumikatva-failure knowledge, or illusion to attain continuity of thought or con so that reality centration 9 anavasthitattva been attained -instability after long practice. -cannot be seen in holding on to concentration which has there are, however, four more distractions: (3) ailgamejayatva- ( i ) dul:tkha-pain or of unsteadiness misery, (2) daurmansya-despair, the body and (4) svasa-prasvas a -unsteady a general surveys the terrain respiration. -way the yogi plans and the enemy and plans the conquest of the to win a battle, counter-measures. -self. -in a similar vyadhi: it will be noticed that the very first obstacle sickness. -if his vehicle broken by ill-health, breaks down, the traveller the aspirant body is the prime instrument can achieve little. -to the yogi his is ill-health of attainment. -or cannot go far. -if the body is health is physical important for mental development, as normally the mind functions through the nervous system. -when the body is sick or the nervous system is affected, the mind becomes restless centration n become impossible. -or dull and inert or meditatio and con introduction 25 styiina: a person suffering and no enthusiasm. -and their faculties but water in listless a ditch stagnates from languor has no goal, no path to follow his mind and intellect rust. -constant flow keeps a mountain stream become dull due to inactivity pure, person is like a living corpse and nothing good can flourish in it. -a for he can concentrate on nothing. -and the doubter destroy themselves. -the unwise, the faithless samsaya: how can they enjoy this world or the next or have any happiness? -seeker should have faith that god is ever springs up in the heart it dries out lust, ill-will, pride and doubt, and the heart free from these hindrances serene and in himself and his master. -he should have faith as faith by his side and that no evil can touch him. -untroubled. -becomes mental sloth, spiritual the and believes pramada: a person suffering from pramada is full of self-importance, lacks any humility what is right or wrong, but he persists and chooses what is of personal everyone and deaf to his words. -in his indifference his selfish and without scruple sacrifice such a person is blind to god's glory to the right and dreams glory, he will deliberately who stands in his way. -is wise. -no doubt he that he alone pleasant. -to gratify passions knows of laziness, is needed. -the attitude alasya: to remove the obstacle (v'frya) hope yearning should be his shield and courage his sword. -he should be free from hate and sorrow. -with faith and enthusiasm he should overcome the inertia is like that of a lover ever giving way to despair. -unflagging enthusiasm of the body and the mind. -beloved but never of the aspirant to meet the craving for sensory objects after they consciously this is the tremendous avirati: have been to the objects out being attached with the aid of the senses which are completely the practice emancipation of pratyahara from desire and becomes which is so hard to restrain. -with them by and he wins freedom from attachment content and tranquil. -abandoned, under his control. -of sense, the yogi learns to enjoy bhranti dar5ana: a person afflicted by delusion and believes that he alone has seen the true light. -he has a false knowledge suffers from 26 light on yoga powerful intellect remaining sets his foot firmly on the right path and overcomes and makes a show of great souls and through their guidance he his weakness. -in the company of but lacks humility wisdom. -by so also a person who cannot overcome the inability alabdha bhumikatva: as a mountain for lack of stamina, to concentrate reality divine music in a dream, but who is unable to recall it moments and cannot he might have had glimpses who has heard in his waking but he cannot see dearly. -he is like a musician repeat the dream. -seek reality. -falls to-reach is unable to the summit climber of has by hard a person affected with anavasthitattva achievements and has come to happy and proud of his (sadhana). -anavasthitattva: work come within sight of reality. -he becomes slack in his practice power of concentration even at this last stage continuous pursue the path with infinite must never sho slackness realization. -ka!hopanishad: been said in the and instruction, nor by subtlety him who longs for him, by the one only by being.' -such a one the self reveals his true and to win unalloyed divine grace descends 'the self is of intellect, which hampers progress he must wait until and determined endeavour patience the final cross-roads he has purity and great of his quest. -he has to and is essential and perseverance on the path of god upon him. -it by study has not to be realised nor by much learning, but whom he chooses. -verily to happiness, pataiijali the best of these is the fourfold karm:ta (compassion), mudita (delight) remedy of and to overcome offered several maitri (friendliness), upeksa (disregard). -the obstacles remedies. -friendliness of her children success maitri is the object of at the patafijali recommends cultivates friends, bearing malice towards none. -not merely friendliness, (atmlyata). -but also a feeling of onen,ess with a mother feels intense because of atmlyata, maitri for sukha (happiness happiness a feeling of oneness. -or virtue). -the yogi turns enemies into maitri and atmlyata for the good and karut:a is not merely showing pity .or compassion and shedding of others. -it is compassion the misery of the afflicted. -economic, mental or moral-to alleviate the yogi uses the tears coupled at the misery (dulfkha) of despair with devoted action to relieve all his resources-physical, pain and suffering of others. -they become strong. -they become brave by his example. -of the fittest', a shelter to one and all. -mudita is a feeling of delight he shares his strength he shares his courage with with the weak until timid until those that are he denies the maxim of the 'survival but makes the weak strong enough to survive. -he becomes at the good work (punya) done by introduction 27 another, himself jealousy has failed even though he may be a rival. -from much heart-burning for another by not showing anger, hatred or the desired through mudita, who has reached goal which he himself the yogi saves to achieve. -upek a: it is not merely a feeling of disdain or contempt for the or one of indifference self-examination to find out him. -it is a searching person who has fallen into vice (apul?-ya) uperiority towards how one would have behaved it is also an examination into which the unfortunate to put him on the right path. -the yogi understands studying by seeing and to all. -to be charitable when faced with the same to see how far one is responsible one has fallen and the attempt this self-study in himself. -them first the faults of others teaches temptations. -for the state thereafter him or the deeper significance of the fourfold remedy of maitri, karuna, cannot be felt by an unquiet mudita and upek a ordinary for an has led me to conclude that munity of the world, the way to achieve a determination pataiijali, man or woman quiet mind is to work with on two of the eight stages of yoga mentioned mind. -my experience in any com pra1).ayama. -asana and namely, by the mind (manas) activity and the hence pataiijali achieving and the breath (pra1).a) activity or the cessation of pral?-ayama recommended are intimately of one affects the other. -control) (rhythmic breath connected for mental equipoise and inner peace . -sisya and guru (a pupil and a master) sadhakas they are (1) m.fdu (feeble), the siva samhitii divides classes. -adhimatra last, world. -(superior) the highest, is and (4) adhimatratama (pupils or aspirants) (2) madhyama (average), (3) (the supreme one). -the into four alone able to cross beyond the ocean of the manifest are those who lack enthusiasm, inclined to bad action, ill, dependent, the guru (teacher eat much, speak harshly, or master) power have weak guides such are in the their criticise the feeble seekers in the path of mantra yoga only. -are rapacious, cowardly, and lack virility. -teachers, of women, unstable, characters seekers can reach enlightenment years. -in twelve from the root 'man', meaning to think. -thought it takes a mind of a feeble sadhaka to be repeated years, long time, perhaps or prayer and still longer with much effort, the sadhaka mantra is derived (the word a sacred mantra thus means of its meaning. -with full understanding for a mantra to take firm root in the for it to bear fruit.) -of even mind, capable of bearing work, speaking gently, moderate hardship, to perfect wishing the such is the in all circumstances, 28 light on yoga seeker. -average yoga, which gives l iberation. -dissolution.) -recognising these qualities, the guru teaches (laya means devotion, him laya absorption or of stable mind, capable truthful, merciful, forgiving, on the practice intent teacher, can reach enlightenment this forceful man in ha ha yoga. -of laya yoga, virile, young, respectf independent, noble, ul, worshipping brave, of yoga, such is a superior seeker. -the guru instructs after six years of practice. -his he of great virility and enthusiasm, good looking, sane of mind, not melancholy, courageous, keeping learned young, studious, in food, with his senses helpful generous, in scriptures, regular skilful, of good character, a supreme ment in three seeker, years. -under control, free from fear, clean, to all, firm, intelligent, independent, forgiving, of gentle speech and worshipping fit for all forms of yoga. -he can reach enlighten his guru, such is although the siva samhita and the hafha yoga pradipika mention lays down required to unite of time within which success the time the period nowhere the divine universal soul. -according to him abhyasa (constant and determined make the mind calm and tranquil. -without foundation. -might be achieved, the individual pataiijali soul with he defines abhyasa as performed with devotion, effort of long duration, (freedom from desires) interruption, a firm which creates and vairagya practice) a way of life, and not merely how to earn a livelihood. -teacher he is a spiritual the study of degree by someone desiring yoga is not like work for a diploma favourable results and tribulations or a university time. -in a stipulated can be of yoga in the path gu with the help of a guru. -(the syllable he alone is a guru who removes conception enlightenment.) -the of a guru is deep and brings and ru means light. -the obstacles, trials removed to a large extent means darkness darkness and significant. -who teaches of the spirit he transmits knowledge knowledge a disciple. -is a si ya, between the relationship he is not an ordinary guide. -one, a guru and a si ya is a very special wife or husband and he devotedly leads his sisya egotism. -that between parent and child, a guru is free from the ultimate transcending friends. -goal without towards shows the path of god and watches path. -he inspires him along that confidence, understanding through and illumination the guru strains hard to see that he absorbs the ages him to ask questions analysis. -any attraction the progress for fame or gain. -he of his disciple, guiding deep discipline, devotion, love. -with faith in his pupil, teaching. -he encour and to know the truth by question and and one who receives such introduction 29 a si ya should possess the necessary he must have confidence, devotion and qualifications of higher a mind, their perfect examples and development. -between of the relationship (the god of death) and nachiketa and arjuna in the enlightenment realisation love for his guru. -the guru and a sisya are those of yama in the ka hopani ad and of sri krishna gftii. -nachiketa and arjuna obtained one-pointed eagerness should hunger for knowledge and have the verance out of curiosity. -not be discouraged pected. -which is coloured by accumulated if he cannot reach the had ex tremendous innumerable thoughts of past to the words of the and questioning spirit guru merely and should faith) (dynamic goal in the time he bhagavad their the si ya patience to calm the past experiences and restless mind (the samskara guru does not enable the sisya of purpose. -he and actions). -merely listening should not go to the he should possess perse of humility, and tenacity it requires residue spirit. -through sraddha whereas virochana to the same prince, a demon obtained brahma to obtain know is borne out by the story of lndra and and faith which he had for his teacher. -preceptor virochana, indra, the to their spiritual and by the love enlightenment, king of gods, and memory was developed their guru. -indra to absorb the teaching. -this virochana. -went together ledge of the supreme self. -both stayed and listened words of did not. -indra's taught a feeling of oneness success. -he had no devotion he remained a doubter. -indra had pride and imagined lectual to brahma. -the approach virochana wanted the practical him later to with his guru. -these were the reasons virochana's memory was developed either that it was condescending of lndra was devotional what he originally intellectual was, an intellectual which he believed was practical. -was motivated for the subject humility, taught or only through knowledge virochana win power. -the subject by his devotion to _ he had for his on his part to go while that of and by curiosity would be useful to his intellect. -for his preceptor. -he returned giant. -while virochana had intel the si ya should above all treasure love, moderation creates moderation love begets courage, generates power. -courage moderation breeds arrogance about a power which will never leave him as he returns primeval without love and decay. -si ya learns from his guru to the leads to over-indulgence abundance power without one, the source of his being. -and tyranny. -is brutish. -abundance the true and humility. -and humility without humility scidhana (a key to freedom) all the important abhyasa (constant texts on yoga lay great emphasis practice). -or on sadhana study sadhana is not just a theoretical 30 light on yoga of yoga texts. -it is a spiritual to yield oil. -wood must be heated to ignite it and bring out the fire within. -must by constant light the in the same way, the sadhaka divine flame within himself. -endeavour. -oil seeds must be pressed hidden practice 'the young, the old, the extremely aged, in yoga by constant not him who practises not. -success in yoga even the sick and the in practice. -success will firm obtain perfection follow him who practises, obtained is not is not obtained nor by talking verily, verses 64-6.) -about it. -constant there is no doubt of this.' -'as by learning the alphabet by the mere theoretical by wearing the dress of a yogi or a sanyasi (a of sacred reading texts. -success recluse), practice - (ha!ha yoga pradipikii, alone is the secret of success. -chapter i , so by thoroughly the sciences, acquires of truth (tattva of the human soul as being identical ing the universe. -'- the knowledge a samhitii, (gherarj4 jna11a), that is the real nature with the supreme spirit pervad chapter i, verse 5 . ) -one can, through practice, practising rnaster all training first physical one it is by the co-ordinated and concentrated efforts of his body, senses, the prize of inner peace and mind, reason and self that a man obtains fulfils the quest of his soul to meet his maker. -the supreme adventure in a man's life is his journey back he needs well developed senses, in his adventure. -kafhopani seeker nachiketa of the first part of the this yoga to the ad, yama (the god of death) explains reach the goal of his body, mind, reason and self. -in the third valli to his creator. -to and co-ordinated by way of the parable of the individual functioning (chapter) in a chariot. -i f the effort is not co-ordinated, he fails 'know the atman (self) as the lord in a chariot, reason as the they say, are the horses, the self, when united of desire are the pastures. -senses, and mind as the reins. -the senses and the can never a charioteer. -charioteer and their objects with the undiscriminating horses of vicious mind ; his senses are like disciplined becomes unmindful, ing from one body to ever pure; he reaches a discriminating journey- the supreme abode 'the senses are more powerful ever impure; another. -the goal charioteer mind, the wise call the enjoyer (bhokt ). -the rein in his mind; his senses are like the his the discriminating ever controls horses. -the undiscriminating he does not reach the goal, wander the discriminating becomes mindful, and is never reborn. -the man who has of the the end to rein in his mind reaches of the everlasting spirit.' -than the objects of desire. -greater than the senses is the mind, higher than superior self and destroy your deceptive (bhagavad gzta, chapter iii, verses 42-3.) -the mind is the reason and by the desire.' -enemy in the shape of to reason is h e -the spirit in all. -discipline yourself introduction 3 1 to realise this not regards only constant practice the questio renunciation, world, for that the yogi does not renounce the n arises is demanded but as to what also renunciation. -as one should renounce. -would mean renouncing takes him away from the lord. -he renounces that all inspiration those who oppose the work ideas and who merely the creator. -talk of moral values and right action come from the lord. -he renounces of the lord, those who spread demonic but do not practise them. -the yogi renounces his own desires, all that knowing the yogi does not renounce self to his actions humanity. -he has no right to the by dedicating that it is fruits he believes of his actions. -action. -he their fruits his privilege cuts the bonds that tie him to the lord or to either to do his duty and that are asleep when duty calls and wake up only to claim while others their rights, rights. -and tranquil the yogi is fully awake to his duty, but asleep over his beings the disciplined hence it is said that man wakes to the light. -in the night of all astiiizga yoga-the eight limbs of yoga the yoga sutra of pataiijali first deals with samadhi, yoga, the third enumerates achieve comes across in his quest, and the (kaivalya). -is divided pada. -the into four chapters or to the second with the means (sadhana) the powers (vibhiiti) that the yogi fourth deals with absolution in the second chapter. -the first ) -the great commandments creed, country, age and time. -they are: ahimsa (non asteya (non-stealing), (non-coveting). -these commandments brahmacharya are disciplines yama the eight limbs of yoga are described of these is yam a (ethical transcending violence), (continence) the rules of morality violence, bring chaos, the roots of these evils are the emotions ment, which and ignorance. -pataiijali the direction satya (truth), and aparigraha for society untruth, and the stealing, thinking of one's may be mild, medium or excessive. -strikes at individual, which if not obeyed dissipation of greed, desire and attach and covetousness. -they only bring pain the root of these evils by changing of yama. -along the five principles ahimsa is made up ahimsii. -the word and the noun himsa meaning killing negative command not to kill, this love embraces father-the lord. -the yogi believes being is to insult particle 'a' meaning of the is more than a or violence. -it meaning, love. -same of the a thing or all children that to kill or to destroy for it has a wider positive kill for food or to protect for we are all creation its creator. -men either 'not' 32 light on yoga from danger. -but merely because a man is a vegetarian, themselves it does not necessarily or that he is a yogi, though a practice is a state of mind, not of diet. -it resides instrument stab an enemy. -the fault is not in the instrument, follow that he is non-violent vegetarian diet in a man's mind and not in the he holds in his hand. -one can use a knife to pare fruit or to is a necessity may be vegetarians, of yoga. -blood-thirsty tyrants but in the user. -to protect their own interests- their own men take to violence for the but violence by temperament bodies, their loved rely upon himself he can do so is wrong. -a man must rely upon god, who is the source of all strength. -ones, their property alone to protect but a man cannot or dignity. -or others. -himself the belief that violence then he will fear no evil. -arises out of fear, weakness, ignorance needed is freedom from fear. -to gain this or restlessness. -to curb it what is most freedom, what is required tion of the mind. -violence their faith upon reality and supposition. -outlook on life and reorienta is a change of decline is bound to when men learn to base rather than upon ignorance investigation and that every creature that he is born to help others and he looks upon has as much right to live the yogi believes as he has. -he believes creation with eyes of love. -he ably with that of others and he rejoices he puts the of joy to all who meet him. -as parents encourage unfortunate first steps, he encourages makes them fit for those more survival. -happiness knows that his life is linked inextric if he can help them to be happy. -of others before his own and becomes a source a baby to walk the than himself and for a wrong done by others, men they plead mercy and demand ;ustice; while for that forgiveness. -the yogi on there should that for a wrong done by himself, while for that done ! -:>y another there should be forgiveness. -others how to live. -always striving to perfect how to improve he shows them by his love and compassion done by themselves the other hand, believes be justice, he knows and teaches himself, themselves. -the yogi opposes the evil in the wrong-doer, but not the wrong wife whilst loving him may still oppose his habit. -opposi for a wrong done. -opposi can live side by side. -a doer. -he prescribes penance not punishment tion to evil and love for the wrong-doer drunkard's tion without love leads to violence; opposing evil in him is the right course that to love a person whilst fighting the a loving to follow. -the battle is won because he fights it with love. -mother will sometimes same way a true follower the evil in him is folly and leads to misery. -beat her child to cure it of a bad habit; in the of ahimsa loves his opponent. -loving the wrong-doer the yogi knows without along with ahimsa go abhaya (freedom from fear) and akrodha introduction 33 only to those who man and paralyses (freedom from anger). -freedom from fear comes lead a pure life. -the yogi fears none and none need fear him, because he is purified by the study of the self. -fear grips a him. -he is afraid of the future, the unknown and the unseen. -he is afraid that he may lose his means of livelihood, but the greatest fear is that of different from his body, which is a temporary house for his spirit. -he sees all beings in the self and the self in all beings and therefore he loses all fear. -though the body is subject to sickness, and death, the spirit that adds zest to life. -he has dedicated his mind, his reason and his whole life to the lord. -when he has linked his entire being to the lord, what shall he then fear? -age, decay remains unaffected. -to the yogi death is the sauce death. -the yogi knows that he is wealth or reputation. -there are two types of anger (krodha), one of which debases the of the first is the mind defective. -in perspective growth. -the root this prevents and makes one's judgement mind while the other leads to spiritual pride, which makes one angry when slighted. -from seeing things the yogi, on the other hand, is angry with himself when his mind fail to stop him stoops low or when all his learning from folly. -he is stern with himself when he deals with his but gentle with the of a yogi, whose heart melts at and firmness for himself go hand in hand, and in his presence all hostilities in him gentleness and experience faults of others. -all suffering. -gentleness are given up. -of mind is an attribute own faults, for others satya. -satya or truth is the highest rule of conduct or morality. -mahatma gandhi said: 'truth is god and god is truth. -impurities burns up the dross in him. -and refines gold, so the fire of truth cleanses as fire burns the yogi and , if the mind thinks thoughts of truth, if the tongue speaks words reality in its based upon truth, then if the whole life is. -infinite. -of truth and for union with the and truth and expresses life must conform strictly ahimsa, which is essentially supposes perfect truthfulness ness in any form puts the sadhaka out of harmony with mental law of truth. -based on love, is enjoined. -in thought, fundamental these two aspects. -to these two facets of reality. -itself through that is why satya pre one becomes fit the funda nature is love word and deed. -untruthful the yogi's truth is not limited abuse and obscenity, and lastly ridiculing is more poisonous to speech alone. -there dealing in falsehoods, are four sins of speech: calumny or telling tales what others hold to be sacred. -the tale bearer than a snake. -the control of speech leads to the 34 light on yoga out of malice. -rooting filled with charity has attained speaks he will be heard with respect remembered towards self-control when the mind bears malice towards to control all. -he who has learnt in a great measure. -none, it is his tongue when such a person his words will be , for they will be good and true. -and attention. -when one who is established in truth prays with a pure heart, then needs come to him when they are really things he really does not have to run after them. -the man firmly established gets the fruit of his actions doing anything. -the source of all truth, his needs and looks after his welfare. -a! -'parently supplies without in truth needed: he god, to possess and enjoy what another has, spring the urge to steal and from this desire a drives covet. -asteya (a= not, steya=stealing), or non-stealing to another what belongs for a different or purpose by its owner. -it thus includes misappropria and misuse. -without to that intended, permission, mismanagement the yogi reduces things that if he gathers needs to the minimum, need, he is a thief. -believing while other men crave for wealth, not only taking asteya. -the desire person to do evil deeds. -the urge to includes but also using something beyond the time permitted tion, breach of trust, his physical he does not really power, fame or enjoyment, the lord. -freedom tions. -muddies and vile and cripples shalt not steal, becomes craving the yogi has one craving and that is to adore from craving enables the stream of one to ward off great tempta tranquillity. -it makes men base them. -he who obeys the commandment of all treasures. -repository a trusted thou that a sweet smell. -of semen the yogi's body develops according religious to the dictionary brahmacharya study and of semen leads to death and its retention there is no fear of death. -hence the injunction means the it is thought self-restraint. -to life. -by the so long that it by concentrated is not one of negation, to sankaracharya, is a man who is engrossed brahmacharya. -life of celibacy, the loss preservation as it is retained, should be preserved of brahmacharya tion. -according brahmacharya) vedic lore, brahman. -brahmacharl. -speech and mind. -this does not mean that the philosophy meant only for celibates. -a bachelor one is has to translate it is not necessary forced austerity (one who study of the constantly in other wor pataiijali, in the and knows that all exists in all is a of the body, of yoga is effort of the mind. -the concept and prohibi observes sacred in the higher aspects ds, one who sees divinity moves in brahman to do with whether a brahmachar1 on continence or married however, lays stress brahmacharya and living has little the life of a householder. -in one's daily living. -for one's salvation to stay unmarried and of brahmacharya without one introduction 35 without experiencing to know divine love. -a house. -on the contrary, all the sm tls (codes of law) recommend human love and happiness, it is not marriage. -almost all the yogis and sages of old in possible india were married men with families of their own. -they shirk their social or moral responsibilities. -are no bar to the knowledge the supreme soul. -did not and parenthood and union with of divine love, happiness marriage dealing with the position of an aspirant who is a householder, free from the company of men in the he should remain in the duties caste or rank; but let him perform these as an instru profession, the sake of place. -for appearances, but not have his heart in it. -he should not renounce siva samhita says: let him practise a retired society, of his ment of the lord, without any thought of the results. -yoga; there is no doubt of by following wisely the method of ing in the midst of the family, holder, his senses, touched by virtue or vice; if to protect he is not polluted by it. -(chapter v, verses 234-8.) -the householder always doing the salvation. -attains practising sin, mankind he commits any yoga is not he who is free from merits and demerits and it. -remain the house has restrained he succeeds duties of a fund of one develops mind and a powerful intellect so in brahmacharya, when one is established vitality and energy, a courageous that one can fight any type of injustice. -forces he the physical the work of the lord, the mental for the spread of intellectual that sparks the torch of wisdom. -for the growth of he will utilise spiritual generates wisely: life. -brahmacharya will use the ones for doing culture and is the battery the the brahmacharl need, means hoarding or collecting. -hoard or collect not really im to be free from it is thus but another facet of asteya (non parigraha is aparigraha. -just as one should not take things one does aparigraha. -hoarding stealing). -so one should not one take anything mediately. -neither should or as a favour from another, yogi feels that the to provide for his faith in god and in himself by keeping before him the image of the moon. -during the dark half the month, the moon rises late when most men are asleep and do not appreciate its beauty. -from its path and is indifferent it has faith that it will be full again when it faces the sun and then men will eagerly things one does not require without working for it poverty of spirit. -the a lack of for this indicates or hoarding to man's lack of appreciation. -wanes but it does not stray future. -he keeps faith await its glorious of things implies its splendour collection rising. -of so by the observance of aparigraha, the yogi makes simple his life as as possible and trains his mind not to feel the loss or the lack of any- 36 light on yoga needs will come to him by itself at the he really the sadhaka thing. -then everything proper time. -the life of an ordinary and frustrations of disturbances series thus there is hardly any possibility has developed equilibrium. -with whatever him beyond is saturated. -in the ninth me alone every moment, i bring shall protect happens to him. -thus he obtains the realms of illusion he recalls the promise chapter devotion, with single-minded full security. -them for ever.' -with an unending man is filled and with his reactions of keeping the mind the capacity to them. -in a state to remain satisfied of takes the peace which and misery with which our world , given by sri krishna to arjuna of the bhagavad gita: 'to those who worship who are in harmony with me i shall supply all their wants and niyama niyama are the rules of conduct that apply to individual while yama are by pataiijali or austerity), (dedicatio universal are: saucha (purity) in their application. -(contentment), discipline, listed tapas (ardour (study of the self) and isvara pranidhana the five niyama n to the lord). -svadhyaya , santo a body is essential purify the body externally, the practice good habits for well-being. -while cleanse asana and prii!.fiiyama of asanas tones the entire body and removes caused by over-indulgence. -prii!.fiiyama the the blood and purifies of the body like hatred, cleansing emotions than the of the mind of its disturbing the lungs, oxygenates physical and pride. -still more important the (buddhi) of impure thoughts. -of the mind are washed off in the waters of bhakti of the intellect the impurities or reason are burned off and joy. -it brings benevolence (saumanasya) and (study of the self). -this internal cleansing banishes saucha. -purity of like bathing it internally. -the toxins and impurities and aerates cleanses but more important nerves. -is the cleansing greed, delusion passion, anger, lust, the intellect is the cleansing of impurities (adoration). -in the fire of svadhyaya gives radiance mental pain, dejection, one sees the virtues is benevolent, the respect which one respecting as ficulties. -(ekagra). -(indriya-jaya). -and see his besides then one is ready to sorrow and despair when one ( daurmanasya). -in others and not merely their faults. -shows for another's virtues, makes him self well and helps him to fight his own sorrows and dif when the mind is lucid, it is easy to make it one-pointed with concentration, one obtains mastery over the senses enter the temple of his own body real self in the mirror of his mind. -sary. -apart from cleanliness purity of body, thought and word, pure food is also neces of food it is also in the preparation necessary it. -to observe purity m the means by which one procures introduction 37 food, the supporting yet consuming as a phase of brahman. -i t should be each morsel one can gain strength becomes pure. -whether or not to be a vegetarian by the tradition matter as each person is influenced bred. -but, in course country in which he was born and vegetarian practitioner one-pointed evolution. -substance of all life, is regarded eaten with th.e feeling that with then food to serve the lord. -is a purely personal of yoga has to adopt a and spiritual attention and habits of the of time, the diet, in order to attain food should be taken to promote health, juicy and burning, nourishing, pungent, i t should be simple, are sour, bitter, unclean. -salty, strength, energy and life. -soothing. -avoid foods which stale, tasteless, heavy and character is moulded by the type of food we take and by how we eat it. -men are the only creatures generally live to eat rather than eat to live. -if we eat for flavours the tongue, we over-eat throw our systems out of gear. -the eats for the sake of sustenance little. -guards himself that eat when not hungry and of which disorders only. -h e does not eat too much or too of his spirit and he looks upon his body as the rest-house and so suffer from digestive yogi believes in harmony, so he against over-indulgenc food, the place is also important e. besides for spiritual practices. -(away from home), in a forest, one should choose a place it is in a distant country difficult to practise in a crowded city, or where it is noisy. -where food is easily procurable, from the elements protected of a lake or river or the sea-shore are hard to in one's room available pest-free. -for practice a place which is free from insects, the banks and with pleasing surroundings. -are ideal. -such quiet ideal places find in modern times; but one can at least make a corner and keep it clean, airy, dry and santosa or contentment has to be cultivated. -a mind that is the yogi feels the lack of nothing and . -. -cannot concentrate. -santosa. -not content so he is naturally yogi. -a contented lord and has done his duty. -and joy. -content. -man is complete contentment to the gives bliss unsurpassed for he has known the love of the he is blessed for he has known truth contentment and tranquillity are states of mind. -differences arise among men because of race, creed, wealth and create discord distract (ekagra) and and there arise conscious is robbed of and perplex its peace. -there is contentment or unconscious learning. -differences which conflicts one. -then the mind cannot become one-pointed and tranquillity 38 light on yoga when the flame of the spirit the sadhaka does not seek the in god. -of one whose reason is firmly established does not waver empty peace of the dead, but the peace in the wind of desire. -from the root 'tap' meaning to blaze, bum, consume by heat. -it therefore means a burning tapas. -tapas is derived shine, suffer pain or effort under purification, acter building all circumstances self-discipline to achieve and austerity. -as a practice may be regarded a definite goal in life. -it involves the whole science of char of tapas. -tapas is the conscious up all desires with the effort to achieve ultimate union this goal. -in the way of without such pure and divine. -which stand makes life illumined, action and prayer have no value. -life without love. -without tapas, the mind cannot reach up to the without tapas, is like divine and to burn a worthy aim an aim, a heart lord. -of three types. -it may relate to the body (kayika), or to mind (manasika). -(ahimsa) (brahmacharya) are tapas of the body. -using words which do not continence to speech and non tapas is (vachika) violence offend, reciting oneself for the consequences to of speech. -developing a mental and balanced in the mind. -the glory of joy and sorrow god, speaking the truth without regard ill of others are tapas and not speaking attitude whereby one remains tranquil and retains self-control are tapas of it is tapas when one works without any selfish motive or hope of reward and move without his will. -with an unshakable faith that not even a blade of grass can by tapas the yogi develops strength in body, mind and character. -he gains courage and wisdom, simplicity. -integrity, straightforwardness and svadhyaya. -sva means self and adhyaya means study or drawing out of the education svadhyaya, svadhyaya is the therefore, is different best that is within a person. -of the self. -is the education from mere instruction education. -when people meet for svadhyaya, parades his own learning where the lecturer his audience. -are of one mind and ing and one heart from svadhyaya they become a part of one's life and being. -have mutual love and respect. -ennobling there is no sermonis speaks to another. -the thoughts are, so to speak, taken into one's bloodstream that arise so that like attending a before the ignorance lecture of and listener the speaker the person practising svadhyaya reads same time that he life. -he look on starts to realise writes and revises his own book of life, at the it. -there is a change in his out is meant for bhakti that all creation introduction 39 (rdoration) divinity that there is divine, moves him is the same that rather than for bhoga (enjoyment), within himself and that moves the entire universe. -of the bhoodan move which is the basis or root rest, but which to sri vinoba bhave (the leader creation the energy which upon which the others is the study of one subject according that all ment), svadhyaya of all other subjects itself does not rest or actions, upon anything. -is to study it is essential to make life healthy, happy divine literature in and peaceful, ignorance bring knowledge. -a pure place. -this study of the sacred will enable the sadhaka to concentrate upon and they arise. -it will put an end a beginning the sadhaka understands regularly books of the world solve the difficult problems of life when to ignorance and it has an end. -there is svadhyaya the sacred books of the world are for all communion with the divine. -to read. -they are not meant for the members of one particular faith alone. -as bees savour the nectar in various flowers, absorbs things in other own faith better. -philology so the sadhaka faiths which will enable him to appreciate is not a language but the science but no end to knowledge. -by of languages, the study his the nature of his soul and gains has no beginning, but of which will enable the student to learn his own language better. -similarly, the study of which will enable a sadhaka the better to appreciate own faith. -of religions, his yoga is not a religion it is the science by itself. -- . -creation purposes; to the lord of are made to flow through the he who knows that all or drunk with power. -he will his head will bow only in worship. -he who has faith in god does not despair. -of the mind, the result is mental power and spiritual one's actions and will is he has belongs to the /svara pranidhiina. -dedication isvara praj?.idhana. -illumination (tejas). -lord will not be puffed up with pride not stoop for selfish when the waters of bhakti (adoration) turbines tion. -while mere physical adoration without strength destroys pleasures senses as they run (greed) for their repetition. -is soka (sorrow). -they have ance; but to control the mind is more difficult. -one's own resources and still not succeeded, help for he is the source of all power. -it is at this stage that bhakti begins. -in bhakti, to the lord and the sadhaka prays: 'i do not know addiction both power and glory. -from the gratification and lobha after pleasures arise then, there illumina strength without bhakti is lethal, mere to of the if the senses are not gratified, to be curbed with knowledge the mind, the intellect moha (attachment) one turns to the lord for is like an opiate. -of character what is good for and forbear after one has exhausted and the will are surrendered 40 light on yoga me. -thy will be done.' -or accomplished. -'mine'. -soul has reached full growth. -others pray to have their own desires gratified in bhakti or true love there is no place for ' i ' and when the feeling of 'i' and 'mine' disappears, the individual when the mind has been emptied of desires of personal of the lord. -in the mind after the objects be filled with thoughts of personal gratification, there is tion, it should with thoughts dragging bhakti without emptying the with wet fuel. -it makes a lot the person who builds it and of those around him. -a mind with desires does not ignite touched with ti e fire of knowledge. -danger of the senses attempts to is like building brings tears to the eyes of practise a fire and glow, nor does it generate when light and warmth mind of desires of smoke and of desire. -gratifica a mind filled the name of the lord is like the sun, dispelling (piir ata) moon is full when it faces the sun. -the individual when it faces the lord. -fullness comes between the full moon and the sun feeling of 'i' and 'mine' casts its shadow ness, all efforts of the sadhaka to gain if the shadow of the earth there is an eclipse. -if the of full upon the experience peace are futile. -all darkness. -the soul experiences actions mirror a man's personality better than his words. -the yogi has learnt the art of dedicating all his actions they reflect the divinity within him. -to the lord and so asana brings steadiness, po ture produces of limb. -a steady and pleasant fickleness of and prevents a sana the third limb of yoga is asana or posture. -health and lightness mental equilibrium merely gymnastic needs a clean airy place, a blanket one needs systems of physical training equipment. -vide the necessary on develops endurance agility, exercises; they are postures. -asanas can be done alone, as the limbs of the body pro weights and counter-weights. -by practising them balance, asanas have been evolved over the centuries vitality. -so as to exercise and great every mind. -asanas are not to perform them one and determination, while for other large playing fields and costly muscle, nerve and gland in the body. -they secure a fine physique, which is strong and elastic the body free from disease. -but their real importance mind. -without being muscle-bound they reduce fatigue and soothe the nerves. -lies in the way they train and discipline and they keep the many actors, acrobats, men also possess they lack control body, but hence they are in disharmony superb physiques athletes, dancers, and have great control over the mind, the intellect and sports over the and the self. -musicians with themselves and one rarely comes introduction 41 across a balanced personality above all else. -though the yogi not think merely of its perfection but of his soul. -among them. -they does not underrate often put the body his body, he mind, intellect does and senses, the yogi conquers the body by the practice of asanas and makes it for the spirit. -he knows that it is a necessary a soul without a body is like a bird deprived of its vehicle a fit vehicle for the spirit. -power to fly. -the yogi he knows that childhood but the soul is not subject garments worn-out aside worn-out casting the yogi believes does not fear death, for time must take its toll of all flesh. -the body is constantly changing and is affected by , youth and old age. -birth and death are natural phenomena takes on new ones, so the to birth and death. -as a man casting the body bodies enters into others that are new. -dweller within off that his body alone, but also for the service has been given to him by the lord not for enjoyment of his fellow men it his during every wakeful moment of his life. -he does not consider who has given him his body will one property. -day take it away. -he knows that the lord by performing asanas, the sadhaka first gains health, which is not which can be purchased with i t is not a commodity be gained by of body, mind and spirit. -sheer hard work. -it is a state of of is health. -and mental distractions the yogi forgetfulness frees himself asanas. -by practising disabilities and mental consciousness mere existence. -money. -it is an asset to complete equilibrium physical from physical he surrenders of the world. -his actions and their fruits to the lord in the service the yogi realises that his life and all its activities and operating are part of the of his pulse and the rhythm of his respiration, or to deny the manifesting in the form of man. -and the throbbing the flow of the seasons divine action in nature, in the beating recognises his body is a temple which houses the divine spark. -he feels that to neglect thing not divine, is a part. -the needs of the body are the needs of the divine spirit which lives through the body. -the yogi does not look heaven-ward to find god for he knows that he is within, antaratma without and finds being known as the (the inner self). -he feels the kingdom of god within and needs of the body and and deny the that heaven lies in himself. -of universal is to neglect universal life of which it life. -he to think of it as some where does the body spirit and but different mind end and the inter-related consciousness. -end and the mind begin? -where does the begin? -they cannot be divided as they are aspects of the same all-pervading divine 42 light on yoga the yogi never neglects or mortifies the body or the mind, but both. -to him the body is not an impediment nor is it the cause of its fall, but is an instrument cherishes liberation ment. -he seeks a body strong as a thunderbolt, healthy suffering so as to dedicate intended. -attained an aim. -just as an unbaked earthen pot dissolves decays. -so bake it hard in the fire of yogic discipline strengthen of the lord as pointed out in the mu1j4akopani ad and free from for which it is the self cannot be nor through heedlessness, by one without strength, it in the service and purify it. -in order to to his spiritual of attain in water the body nor without soon l.ike the locust (salabha) and the the names of the asanas are significant and illustrate like the the principle like (nakra). -(vrschika) are named tree (vrk a) and frog (bheka or (kiirma), the after vegetation ; some after aquatic animals and amphibians tortoise there are asanas called after birds like the max:>-9iika) or cock the heron (baka), the peacock (mayiira) and the swan of evolution. -some the lotus (padma); some after insects scorpion the fish (matsya), the the crocodile (kukku a), (harilsa). -they are also named after quadrupeds the horse (vatayana), that crawl like human embryonic after legendary 'ages like bharadvaja, y having asanas ods of the hindu pantheon and some recall the avataras, .ons of divine power. -whilst performing asanas the yogi's body named overlooked. -asanas are and hanuman, son of the wind. -like the dog (svana), creatures heroes like vfrabhadra kapila, the serpent (bhujailga) are not forgotten, nor is the are also called after or incarna named after them. -some asanas and the lion (sirilha). -state (garbha-pinda) the camel (u ra) are remembered vasigha and visvamitra creation, a variety of creatures. -many forms resembling for he knows that throughout assum..!s trained not to despise any creature, whole gamut of insect to the most perfect which assumes innumer sage, there breathes able forms. -he knows that the highest form is that of the formless. -he finds unity in universality. -of brahman flows effortlessly sadhaka. -is that in which the thought through the mind of the his mind is the the same universal and incessantly from the lowliest true asana spirit, dualities like gain and loss, victory and defeat, fame and shame, prfu}ayama, and soul vanish through mastery of the asanas, body and mind, mind and the sadhaka then passes on to path of yoga. -in prfu}ayama practices the windpipe, membranes, parts of the body which are actively full impact of the force of prax:>-a, seek to master prax:>-ayama in by its improper practice respiratory diseases the fourth stage in the and nasal passages the nostrils, only the lungs and the diaphragm are the feel the these alone the breath of life. -therefore, a hurry, as you are playing with life itself. -will arise and the involved. -nervous do p.ot introduction 43 system will be shattered. -diseases. -is essential physical limitations of to have the never attempt to practise personal supervision his pupil. -by its proper practice one is freed pra ayama alone by yourself. -for from most it of a guru who knows the prarjayama i t stretching or restraint. -life, vitality, wind, breaths. -ayama means length, pral).ayama thus connotes extension just as the word yoga is one of wide import, so also is praj).a. -pral).a energy or strength. -means breath, respiration, also connotes the soul as opposed to the body. -the word is generally used in the plural to indicate vital expansion, of breath and its control. -this control breathing, piiraka (filling (emptying the lungs), and (3) retention where there is no inhalation kumbhaka. -in ha ha yoga texts kumbhaka is also used generic sense to include all the three tion, exhalation which is called rechaka or holding the breath, a state which is termed in a loose namely, (i) inhalation up); ( 2) exhalation is over all the functions of or inspiration, or exhalation, processes of inhala or expiration, and retention. -which is termed respiratory a kumbha is a pitcher, water pot, jar or chalice. -a water pot may with water, or it may be with air. -similarly, (the lungs be emptied of all air and filled completely emptied of all water and filled completely there are two states of kumbhaka namely (i) when breathing is suspended after full inhalation being completely filled with life giving air), and (2) when breathing is suspended after full exhalation (the lungs being emptied of all noxious air). -the first of these states, but before exhalation where breath is held after a full inhalation, gins, is known as antara kumbhaka. -the second, where breath is held after a full exhalation, is known as bahya while bahya means outer or kumbhaka. -antara means inner exterior. -full inhalation tion and inhalation suspended and restrained. -the interval time between (an tara kumbhaka) or between full exhala breathing is thus, kumbhaka is and exhalation (bahya kumbhaka). -in both these types but before inhalation begins or intermediate or interior, be pral).ayama is thus the science of breath. -it is 'as lions, elephants the hub round which and tigers are tamed very the wheel of life revolves. -slowly and cautiously, slowly in gradation so should pr a be brought under control very measured according to one's capacity and physical limitations. -yoga pradipika (chapter i i , verse i6). -otherwise it will kill the practitioner,' warns the hafha the yogi's life is not measured by the number of his days but by the number of his breaths. -therefore, he follows the proper rhythmic patterns of slow deep breathing. -these rhythmic patterns strengthen of prat;tayama. -is the true rechaka is the true piiraka 44 light on yoga system, soothe the nervous system and reduce craving. -cravings diminish, the respiratory as desires and fit vehicle for concentration. -wind, into his system like hiccough, pupil introduces asthma, cough, catarrh, pains in the head, eyes and ears and nervous steady and proper irritation. -i t takes a long time to learn slow, deep, the mind is set free and becomes by improper practice of several disorders pra:r:tayama the a inhalations and exhalations. -master this before attempting kumbhaka. -as a fire blazes brightly when the covering of ash over it is scattered by the wind, the divine fire within the body shines in all its majesty when the ashes of desire are scattered by the practice 'the emptying the mind of the whole 9f its illusion the realisation (exhalation). -and the steady sustenance (inhalation). -is the true kumbhaka (retention). ' -that " i am atma (spirit), of the mind on this conviction this is true pranayama,' says . -sankaracharya. -every living creature unconsciously breathes the prayer 'so'ham' am i ) with each inward (s = he: aham= i -he, the immortal spirit, breath. -so also with each outgoing breath each creature prays ( i am he). -this ajapa-mantra (unconscious for ever within each living creature throughout life. -the yogi fully realises from all the fetters that bind his to the lord as a sacrifice and receives the breath of life from the lord as his blessing. -the significance of this ajapa-mantra soul. -he offers up the very and so is released breath of his being repetitive prayer) goes on 'harilsaj:l' pra:r:ta in the body of the individual (j1vatma) is part of the cosmic breath of the universal spirit (paramatma). -an attempt is made to harmonise the individual (brahma:r:t9a-pra:r:ta) breath (pi:t:j. a-pra:r:ta) of pra:t:j.ayama. -with the cosmic through the practice breath i t has been said by kariba ekken, a seventeenth-century mystic ; 'if for when you would foster a calm spirit, that is under control, the heart any before attempting spasmodic, thing, first regulate your breathing on which your temper will be softened, first regulate your breathing; will be at peace; but when breathing is then it will be troubled. -your spirit calmed.' -therefore, the chitta (mind, reason and ego) is like a chariot yoked to a team of the chariot moves in the direction powerful horses. -one of them is pra:r:ta (breath), (desire). -animal. -if breath prevails, in check and the mind is and the mind is agitated science of breath and by the stilled. -and troubled. -regulation if desire prevails, therefore, the desires are controlled, the other is vasana of the more powerful the senses are held breath is the yogi masters the in disarray and control of breath, he controls the mind and stills the eyes are its constant movement. -in the practice kept shut to prevent the mind from wandering. -of pra:r:tayama 'when the introduction 4 5 praj?a and the manas (mind) have been absorbed, ensues.' -(hafha yoga pradfpikii, chapter iv, verse 30.) -affects the rate of breathing; an undefinable joy equally, as the very object mind, the yogi first learns pranayama excitement. -deliberate excitement emotional of breathing regulation of yoga is to control and still the to master the breath. -reach the stage of pratyahara. -concentration (dhyana). -checks emotional this will enable him to control the senses and so only then will the mind be ready for the mind is said to be twofold-pure and impure. -it is pure when it and impure when it is in union with and freeing it from sloth and which is is not lunacy (amanaska), this state of mindlessness state of the mind when it is free from one reaches the state of mindlessness free from desires by making the mind motionless is completely desires. -distractions, the supreme state of samadhi. -or idiocy but the conscious there is a vital difference thoughts lunatic on the one hand, and a yogi striving to ness on the other. -the former is careless ; the carefree. -and the abandonment designated it is the oneness of the of all conditions and desires. -yoga. -breath and mind and so also of the senses of existence and thought that is achieve a state of mindless latter attempts to be between an idiot or a in five main to the various functions the function of eliminating the human body is classified forms of energy is air. -this vital are termed vayu (wind) and the five (here the generic term is used to designate the in the region of the heart and controls in the ha ha yoga texts according energy. -these priirja viiyu. -one of the most subtle energy which also pervades categories performed by the main divisions are: prat:ta particular), which moves tion; apana, which moves in the sphere of the lower abdomen and controls stokes the gastric fires cavity and controls thoracic pervades and breath. -relieves movements of the eyelids entering nasal passages and for the intake of extra oxygen in a tired body devadatta, by causing a yawn, and lastly dhanariljaya, which remains in the body even after death and sometimes air and food; and vyana, which the energy derived from food vayiis. -these are: naga, which the by belching; kiirma, which controls to prevent foreign matter or too bright a light passing up the down the throat by making one sneeze or cough; the eyes; k kara, which prevents udana, which dwells there are also five subsidiary urine and faeces; samana, which the entire body to aid digestion; and distributes the intake of bloats up a corpse. -which provides substances abdominal pressure respira in the pracyahara if a man's reason succumbs to the pull of his senses he is lost. -on the 46 light on yoga other hand, if there is rhythmic control of breath, the senses instead of running after external objects of desire turn inwards, and man is set free from their tyranny. -this is the fifth stage of yoga, namely, pratyahara, control. -where the senses are brought under is reached, the sadhaka self by recalling when this stage adoration (bhakti) he needs the insulation of goes through to overcome the deadly but attractive a searching examination. -spell of sensual objects, to his needs mind the creator who made the objects of his desire. -he also the lamp of knowledge of his divine heritage. -the mankind the cause of bondage and bound to the objects of desire and there is bondage when the mind craves, something. -the mind becomes pure when all desires and both the good and the pleasant present themselves annihilated. -and prompt them to action. -the others driven by their desires, the very mind, in truth, is for it brings bondage if it is when it is free from objects. -grieves or is unhappy over fears are to men prefer the purpose of life. -the yogi feels joy in what he is. -he knows how yogi prefers the good to the pleasant. -pleasant to the good and miss liberation; liberation lives in peace. -at to stop and, therefore, bitter as poison, but he perseveres the end it will become as sweet as nectar. -others hankering for the union of their senses with the objects of their prefer that which at first seems sweet as as poison. -first he prefers that which is in his practice knowing well that in nectar, but do not know that in the end it desires, will be as bitter the yogi knows that the path towards satisfaction sensual desires is broad, but that it leads to destruction the sharp edge of a are many who follow it. -the path of yoga is like razor, narrow and difficult to tread, and there are few who find it. -the lie within himself. -yogi knows that the paths of ruin or of salvation of the senses by and that there according to hindu philosophy, consciousness manifests in three for man, his life different qualities. -the entire cosmos are the emanations of one and the same prakrti (cosmic matter or substance)-emanations that differ in designation through the predominance attributes) of one of the gu!fas. -these gu!fas (qualities and his consciousness, together with are: or illuminating, pure or good quality), 1 . -sattva (the and mental serenity. -2. rajas (the quality of mobility active and energetic, tense and 3 tamas (the dark and restraining counteracts the tendency of rajas to work and or activity), quality), wilful, and which obstructs and of sattva to reveal. -which makes a person which leads to clarity tamas is a quality of delusion, obscurity, person in whom it predominates is inert and inertia and ignorance. -plunged in a state of torpor. -a the quality of sattva leads towards the divine and tamas demonic, while in between these two stands rajas. -towards the introduction- 4 7 the sacrifices gifts given by each performed, the individual vary in the faith held, the food consumed, austerities accordance undergone and the with his predominating g a. he that is born with tendencies and self-control truthful he is generous is non-violent, his labour, with malice towards none and charity craving. -resolute, he is gentle, modest and steady. -being free from perfidy and pride. -led. -he towards the divine is fearless and pure. -the study of the self. -he the fruits of working only for the sake of work. -he has a tranquil pursues and free from anger. -he renounces mind, towards all, for he is free from he is illumined, clement and a man in whom raj6-gur:ta predominates as he is passionate and covetous, desires envy and deceit, his easily distracted as affectionate. -of lust and hatred, unsteady, tive. -he seeks the patronage from unpleasant and his stomach greedy. -fickle and of friends things and clings well as ambitious are insatiable. -he is and acquisi he shrinks and has family pride. -is sour ones. -his speech to pleasant he hurts others. -being full has inner thirst and is he that is born with demonic tendencies is wrath, cruelty he is full of conceited. -there is neither purity, nor right passions. -delusion, by numerous desires, of sensual the working of the mind of persons with different bewildered these addicts pleasures fall into hell. -conduct, and ignorance. -deceitful, insolent in such people their gratify caught in the web of nor truth. -they and predominating towards a man in whom should not it thus : 'others type is interpret commandment ways of approach them.' -the raj6-guna predominates might by their different like 'thou shalt not covet.' -a gunas may be illustrated universal tam6-gur:ta covet what is mine, no matter how i obtained it. -destroy who would construe others' as a matter of policy, principle. -and the spirit as a matter righteousness punishment to keep him honest. -the commandment as goods lest they covet mine.' -he will follow the letter but not the true spirit a person of sattvika of the precept of eternal value. -he will be righteous not because there is a a calculating temperament alone, and of the law of the law as a matter of will follow both the letter if they do, i shall person self-interested meaning: 'i will not covet for the sake of human law imposing as a matter of principle and not of policy, and disciplined the yogi who is also human is affected by these three constant study (abhyasa) which his senses tend to pursue, he actions are effort he weeds out and eradicates learns which thoughts, by rajas. -prompted by tamas and which such thoughts of himself words and with unceasing and of the objects as are prompted by gur:tas. -by his 48 light on yoga tamas and he works to achieve a sattvika sattva-gu! -:fa towards the ultimate alone remains, goal. -the human soul has advanced a frame of mind. -when the long way like unto the pull of gravity is the pull of the gunas. -as intensive discipline are needed to experience the wonder of and rigorous research weightlessness discipline fur'lished with the creator in space, so also a searching self-examination and the by yoga is needed by a sadhaka to experience union of space when he is freed from the pull of the gu!:fas. -or of the and he looks at once the sadhaka has experienced the fullness of creation (vairagya). -his thirst ctr j:fa) for objects of sense vanishes he experiences honour or dishonour creator, them ever after with dispassion in heat or cold, in pain or pleasure, in virtue or vice. -he treats the two imposters- triumph and disaster-with equanimity. -he has passed beyond the pull of the gunas and has become a gunat'ita (one who has transcended death, from pain and sorrow and becomes immortal. -identity a man, scorning as he lives experiencing nothing, he has no self soul. -such the gu!:fas). -he is then free from birth and leads all things to the path of the fullness of the universal he has emancipated perfection. -no disquiet and in himself from these pairs of opposites. -. -. -dharana . -has been tempered by asanas, when the mind has been when the body of pra! -:fayama refined by the fire under control by pratyahara, dhara!:fa. -in which he to achieve this state of complete the mind is an instrument is completely here he is concentrated and when the senses have been brought the sadhaka reaches the sixth stage called engrossed. -wholly on a single the mind has point or on a task in order to be stilled absorption. -which classifies, judges and co-ordinates the impressions oneself. -from the outside world and those that arise within mind is the product of thoughts which are difficult to restrain for to get the best out of an instrument, mind is the instrument they are subtle and fickle. -a thought which is well guarded by a con trolled mind brings happiness. -one must know how it works. -the and it is therefore necessary to consider in five groups. -the are classified the mental forces are scattered, neglect. -dominant. -and distracted. -but the desires state the mind is foolish, dull and stupid. -to know what it first of these is the k ipta being in disarray the second is the vik ipta a capacity here there is are not marshalled here the mind hankers after objects, and in a state of the rago-guj;ia wants and here the tamo-guna state, where the to enjoy the fruits of one's efforts, for thinking mental states state, where then in the miidha loss and at a and controlled. -predominates. -how it functions. -it is confounded the fourth mind is agitated being introduction 49 and the mental faculties are concentrated state of the mind is the ekagra (eka= one; agra= foremost) state, where the mind is closely attentive on a single object or focussed on one point only, with the sattva-g a prevailing. -the knows exactly what he wants, so purpose. -at times the ruthless of the cost to others, can create great misery, and it often happens that even if the desired object is achieved it leaves behind a bitter ekagra person has superior intellectual powers pursuit of the desired object, irrespective he uses all his powers to achieve his and taste. -provides us arjuna, the mighty bowman of the epic mahabharata, by dharapa. -once dro a, called upon one by one to describe the target, which the preceptor with an example of what is meant of the royal princes, organised an archery contest to test their ficiency. -they were was pointed out to them. -i t was a nesting bird. -some princes tree or the bough on which the the grove of trees, others the particular first the bird. -then nest stood. -when arjuna's tum came, he described he saw only its head, and lastly he could see nothing but the shining eye of the bird, which was the centre of the target chosen by dro a. described pro where the senses start roaming unchecked, there is danger, however, of an ekagra person becoming supremely the mind follows egotistical. -suit. -they cloud a man's judgement and set him adrift like a battered ship on a storm-tossed even keel and the helmsman needs a star to steer her person needs bhakti (adoration divinity the right direction. -and 'mine' disappears. -on so that he goes on always in sea. -a ship needs ballast to keep her on an of the lord) and concentration he will not know happiness to keep his mental equilibrium until the sense of 'i' by. -the ekagra the last mental state is that of niruddha, where the mind (manas), are all restrained (buddhi) and ego (aharilkara) intellect faculties are offered to the lord for his use and in his service. -here there is no feeling of ' i ' and 'mine'. -as a lens becomes more luminous when great light is tinguishable intellect thinks of nothing but him, who is the creator of thought. -thrown upon it and seems to be all light and undis from it, so also the sadhaka who has given up his mind, and ego to the lord, becomes one with him, for the sadhaka and all these without ekagrata or concentration one can master nothing. -without which shapes and controls the universe, one man. -within oneself or become a universal concentration on divinity, cannot unlock the divinity to achieve this concentration, abhyasa or study of the single element that of all beings, who converts his one form into many. -the sadhaka, upon aum, which is his symbol, to achieve therefore, ekagrata. -what is recommended is eka-tattva pervades all, the inmost concentrates self 50 light on yoga aum: according to sri vinoba bhave, the latin word omne and the word aum are both derived from the same root meaning all and sanskrit both words convey the concepts of omniscience, and omnipresence another word for aum is pra ava, which is derived from omnipotence. -the root nu meaning to praise, to which is added the superiority. -prefix pra denoting means the best praise or the best prayer. -the word, therefore, the symbol aum is composed of three syllables, namely the letters a, u, m, and when written has a of the various interpretations given to convey its meaning. -it may be mentioned here to crescent and dot on its top. -a few instances the letter a symbolises the conscious or waking state (jagrata sleep state (su upta-avastha) the letter u the dream state (svapna-avastha) and the letter m avastha), the the dreamless of the mind and spirit. -entire symbol, together with the crescent and the dot, stands for the , which combines all these states and fourth state (turiya-avastha) transcends them. -this is the state of samadhi. -the letters a, u and m symbolise respectively speech (vak), the mind (manas) and the breath the living spirit, which is but a portion of the divine spirit. -oflife (pr a), while the entire symbol stands for the three letters also represent the dimensions depth, while the entire symbol represents limitations of shape and form. -of length, breadth and which is beyond the divinity, the three letters a, u and m symbolise the absence of desire, fear and anger, while the whole symbol stands prajfia), one whose wisdom is firmly established the three genders, masculine, they represent for the perfect man (a sthita in the divine. -feminine and neuter, together with the creator. -while the entire symbol represents all creation they stand for the three gu as or qualities of sattva, rajas and tamas, while the whole symbol represents and gone beyond the pull of the gu as. -correspond the letters to the three tenses-past, present and future a gu afita, one who has transcended the while the entire symbol stands for the creator, who transcends limitations of time. -they also stand for the teaching imparted by the mother, the father and the guru respectively. -the knowledge of the self, the teaching which is imperishable. -the a, u and m depict the three stages of yogic discipline, the entire symbol represents brahma vidya, namely, samadhi, as ana, pra ayama the goal for which the three stages are the steps. -and pra tyahara. -the en tire symbol represents they represent the triad of divinity, namely, brahma-the creator, vi u-the maintainer, whole symbol is said to represent brahman from which the universe emanates, has its growth and fruition and siva-the destroyer of the universe. -the and into which it merges in the end. -i t does not grow or change. -many change and pass, but is the one that ever remains unchanged. -brahman introduction 5 1 the letters a, u and m also stand for the mantra 'tat twam asi' ('that thou art'), the realisation entire symbol stands-for from the confines of his body, mind, intellect the importance of man's divinity which liberates this realisation, after realising and ego. -within himself. -the the human spirit of aum, the yogi focusses his attention on his beloved deity adding aum to the name of the lord. -the word aum being too vast and too abstract, mind and reason by focussing on the name of the lord and word aum with one pointed devotion and so experiences meaning of the mantra. -the yogi recalls adding the the feeling and he unifies his senses, will, intellect, the mu1jcfakopanifad : 'taking as a bow the verses of the great weapon of the upani ad, one should put upon it an arrow to the sharpened by meditation. -essence of that, penetrate mystic syllable aum is the bow. -the arrow is the self (atma). -brahman is the target. -by the undistracted to be in it, as the arrow in the mark.' -it with a thought directed as the mark1 my friend. -the stretching the imperishable man is it penetrated. -one should come dhyana as water takes the shape of its container, an object is transformed thinks of the all-pervading through long-continued divinity. -divinity into the shape of that object. -the mind which devotion transformed which it worships, is ultimately into the likeness of that the mind when it contemplates when oil is poured from one vessel to another, one can observe the uninterrupted, as the filament in an electric flow. -when the flow of concentration is is a regular uninterrupted when there the yogi's mind will be illumined steady constant the state that arises is dhyana (meditation). -bulb glows and illumines of electricity, breath, senses, mind, reason his contemplation-the universal spirit. -sciousness there is no other feeling except a state of supreme bliss. -like a streak of lightning the light that shines beyond the earth and the heavens. -he sees yogi sees the light that shines in his own heart. -he becomes a light unto himself and others. -and ego are all integrated which has no qualification he remains in a state of con by dhyana. -his body, whatsoever. -in the object of current the signs of progress on the path clearness of yoga are health, a sense of of countenance steadiness, physical lightness, he has of odour of the body and freedom voice, sweetness a balanced, serene and a tranquil mind. -he is the very symbol of all his actions to the lord and taking refuge in humility. -from craving. -he dedicates and a beautiful 52 light on yoga him, frees himself from the bondage of karma (action) ]ivana mukta (a liberated soul). -and becomes a 'what becomes of him who strives and fails to reach the end of yoga, who has faith, but wh_ose mind wanders away from yoga?' -to this query of arjuna, the lord sri krishna replied: of the pure yogis; but man. -he dwells long years in the heaven 'no evil can befall a righteous of those who did good, and then he is reborn in the house and the great. -he may even be born in a family of illumined to be born in such a family is most difficult in this world. -he will regain the wisdom attained in his former life and strives ever for perfection. -because of his former study, practice onwards, the yogi ever strives with a soul cleansed of sin, attains perfection goes beyond those who only follow the path of austerity, service. -he who adores me with faith and whose heart gita, chapter vi, verses 38 to 47.) -supreme goal. -the yogi knowledge or arjuna, be thou a yogi. -the greatest of all yogis is lives and reaches the which drive him ever through many and struggle therefore, abides in me.' -(bhagavad samadhi samadhi is the end of the sadhaka's quest. -at the peak of his meditation, state of samadhi, where his body and senses are at rest he passes into the as if he is asleep, his faculties of mind and reason are alert as if he is awake, yet he has gone beyond consciousne ss. -the person in a state of samadhi is fully conscious and alert. -all creation is brahman. -the sadhaka is tranquil and worships it as that from which he came forth, as that in which he breathes, as that smaller into this the soul within the heart is than the sky, containing into which he will be dissolved. -than the smallest seed, yet greater all works, all the sadhaka enters. -then there remains no sense of 'i' desires. -mind and the intellect or 'mine' as the working of the body, the have stopped as if one is in deep sleep. -the sadhaka has attained true yoga; truth and unutterable there is only the experience joy. -the mind cannot find there is a peace that passeth all understanding. -words to describe the state and the tongue fails to utter them. -com paring the experience say: 'neti! -neti ! ' --' i t is not this! -i t is not this! ' -the state can only be expressed world and is merged in the eternal. -there is then no duality between the knower and the known for they are merged like flame. -with other experiences, of consciousness, by profound silence. -camphor and the the yogi has of samadhi the sages departed from the material there wells , sung by sankaracharya up from within the heart of the in his atma $afkam. -yogi the song of the soul. -- song of the soul introduction 53 i am neither ego nor reason, i cannot be heard nor cast into words, in light and wind i am not found, nor yet in earth and sky am i. consciousness bliss of the blissful and joy incarnate, i am neither mind nor thought, caught: nor by smell nor sight ever i have no name, i have no life, i breathe no vital air, no elements have mo lded me, no i have no speech, no hands and feet, nor means of evolution consciousness bodily sheath and joy am i, and bliss in dissolution. -is my lair: i cast aside hatred and passion, no touch of pride caressed me, so envy never did breed: beyond all faiths, consciousness and joy am i, and bliss is my attire. -i conquered delusion and greed; past reach of wealth, past freedom, past desire, vice, or pleasure and pain are virtue and nor sacred texts, nor offerings, nor prayer, nor pilgrimage: i am neither food, nor eating, nor yet the eater am i consciousness bliss of the blissful and joy incarnate, not my heritage, am i. of death, no chasms of race divide me, i have no misgiving no parent ever called me child, no bond i am neither disciple consciousness and joy am i, and nor master, i have no kin, no friend merging in bliss is my end. -ofbirth ever tied me: neither knowable, knowledge, i dwell within the senses but they are not my home: ever serenely consciousness and joy am i, and bliss is i am neither free nor bound balanced, where i am found. -nor knower am i, formless is my form, part ii yogasanas_, bandha and kriya hints, cautions, technique and effects indicate these of the asana; the lower (after the name of each asana, there is a number with an asterisk. -numbers before an asterisk the intensity the number, the easier the asana, the higher the number, the more diffi cult the asana. -the easiest is num bered 'one*', the most difficult 'sixty*'.) -yogasanas hints and cautions asanas for t he practice of the requ sites 1 . -without firm foundations a house cannot stand. -of the principles for building of asanas without without the practice of yama and niyama, which lay down firm foundations practice the backing of yama and niyama is mere acrobatics. -there cannot be an integrated personality. -character, 2. the qualities and perseverance demanded from an aspirant are discipline, without interruptions. -faith, enaci ty to practise regularly cleanliness andfood 3 before starting the bowels evacuated. -student is constipated to practise topsy-turvy or it is not possible asanas, the bladder should be emptied and poses help bowel movements. -i f the of asanas, start with slr asana and sarvangasana to evacuate the bowels before and their the practice variations. -advanced asanas attempt other asanas only never practise without having first evacuated after evacuation. -the bowels. -bath 4. asanas come easier after taking a bath. -after doing them, the body feels sticky due to perspiration and it is minutes later. -taking a bath or a shower both before and after practising asanas refreshes to bathe some fifteen the body and mind. -desirable food 5 asanas should preferably be done on an empty stomach. -if this is difficult, a cup of tea or coffee, cocoa or milk may be taken before doing them. -they may be practised one hour : fter a very light meal. -allow starting the asanas. -at least four hours to elapse after a heavy meal before food may be taken half an hour after completing without discomfort the practice. -t me 6. the best time to practise evening. -i n the morning asanas do not come easily as the body is stiff. -the mind, however, is still fresh but its alertness and is either early in the morning or late in the determination 58 light on yoga asanas well. -in the evening, is able to do the with greater ease. -diminish as time goes by. -the stiffness of the body is conquered by regular practice and one the body moves more freely than in the mornings, and the asanas come practice in the morning makes one work better and better in one's vocation. -i n the evening it removes the fatigue of the day's strain and makes one fresh and calm. -difficult asanas should, be done in the morning when one has more determination therefore, variations stimulative asanas (like paschjmottanasana) should be practised sarvangasana in the evening. -sir asana, and their and and ' sun 7. do not practise asanas after being out in the hot sun for several hours. -place 8. they should be done in a clean airy place, free from insects and noise. -9 do not do them on the bare floor or folded blanket laid on a level floor. -on an uneven place, but on a cautions io. -no undue strain should be felt in the facial muscles, ears and eyes or in breathing during the practice. -keep the eyes open. -then you will know what closing of the eyes i i . -i n the beginning, you are doing and where you go wrong. -if you shut your not be in a position to watch the requisite the direction closed only when you are perfect in a particular you be able to adjust the even in which you are doing the pose. -you can keep your eyes will eyes you will movements of the body or bodily movements and feel the correct stretches. -asana for only then mirror i2. -if you are doing the asanas in front of a mirror, keep it perpendicular to the floor and come down to ground level, for otherwise the poses let it will look slanting due to the angle of the mirror. -you will not be able to observe the movements or placing of the head and shoulders in the topsy-turvy poses unless the mirror reaches down to the floor. -the brain i3. -during the practice of asanas, it is the body alone which should be active while the watchful and alert. -if brain should remain passive, they are done with the brain, then you will not be able to see your own mistakes. -y ogasanas, bandha and kriya 59 breathing i4. -in all the asanas, the breathing only and not through the mouth. -should be done through the nostrils i 5 do not restrain staying in it. -follow the technique sections while the breath while in the process of the asana or in the regarding breathing given instructions of the various asanas as described hereafter. ' -savas ana i 6. after completing for at least io to i5 minutes, as this will the practice remove fatigue. -of asanas always lie down in savas ana asanas and pr0.1jo.y0.ma the hints and cautions for the practice (see part ill). -pranayama may be done either very 1 7 . -read carefully before attempting it early in the morning before the asanas or in the evening after completing them. -i f early in the morning, minutes: then a few minutes of to elapse, during asanas. -if, however, these are done in the evening, allow at least half hour to elapse pranayama may be done first for i 5 to 30 s vasana, and after allowing some time which one may be engaged in normal activities, practise an before sitting for praj;j.ayama. -of pranayama for persons provisions special i 8. do not start with s'ir asana dizziness or uttanasana, and adhomukha ' suffering from dizziness or blood pressure and sarvangasana if you suffer from high blood pres ure. -first practise paschimottanasana svanasana before attempting topsy-turvy poses like s1r asana paschimottanasana, order. -and sarvangasa a and after doing these poses repeat adhomukha svanasana and uttanasana in that i 9 all forward bending poses are beneficial either high or low blood pressure. -for persons suffering from special warning for persons affected by pus in the ears or displaced retina 20. those suffering from pus in the ears or displacement should not attempt topsy-turvy poses. -of the retina special provisions for women : avoid asanas during the menstrual period. -but if the 21. menstruation flow is in excess of normal, u pavistha konasana, baddha konasana, v1rasana, janu performed with beneficial effect. -on no account stand on your head during the menstrual period. -paschimottanasana and uttanasana may be s1r asana, it , 6o light on yoga pregnancy poses and the forward during the first three months of bending asanas may the spine should be made for at this time and no pressure 22. all the asanas can be practised all the standing pregnancy. -be done with mild movements, elastic strong and baddha kol)asana out pregnancy bending immediately the pelvic muscles considerably throughout during labour. -. -pr3j)3yarna pregnancy, without as regular and the small and upavigha kol)asana should be felt on the abdomen. -may be practised after meals) as these two asanas through forward will strengthen labour pains may be practised help considerably of the back and also reduce retention deep breathing will (kurnbhaka) at any time of the day (even after meals, but not after delivery 23. no asanas should thereafter as mentioned be practised in appendix with comfort. -be done during the first month after delivery. -they may be practised mildly. -gradually increase the course i . -three months after delivery all asanas may effects of asanas causes discomfort 24. faulty practice this is sufficient the fault for yourself, well and get his guidance. -it is better to approach to show that one is going wrong. -if you c mnot nne and uneasiness within a few days. -a person who h::ts practis r: 25. the right method of doing asanas brings lightness ing feeling in the body as well as in the mind and a body, mind and soul. -feeling of oneness of and an exhilarat 26. continuous will discipline become a new man. -practice will change the outlook himself in food, sex, cleanliness of the practiser. -he and character and will an asana, i t comes with effortless movements 27. when one has mastered causes no discomfort. -performing asanas, found in creation- he learns that in all spirit presence render unto the the bodily. -the student's from the lowliest these there breathes within himself of god in different asanas feet of the lord. -of god. -he looks insect sage-and to the most perfect spiri t -the the same universal and feels the while practising which he does with a sense of sur ease and while become graceful. -numerous forms of life body assumes yogasanas, bandha and kriya 61 a san as i . -tacfasana (also called samasthiti) ta9a means a mountain. -is standing still, stands firm and erect as ta9asana a mountain. -steadiness. -one* (plate 1) therefore this is the basic a pose where one standing pose. -implies sarna means upright, straight, unmoved. -sthiti technique i i . -stand erect with the feet together, each other. -rest the heads toes flat on the floor. -of metatarsals the heels and big toes touching on the floor and stretch all the 2. tighten the knees and pull the knee-caps pull up the muscles at the back of the thighs. -up, contract the hips and 3 keep the stomach in, chest forward, spine stretched straight. -up and the neck 4 do not bear the weight but distribute it evenly on them both. -of the body either on the heels or the toes, 5 ideally the sake of convenience, arms are stretched out over the head, one can place them by the side of the thighs. -in tadasana the but for 62 light on yoga each of the standing starting the thighs. -with the pupil poses described below can then in tadasana with palms by the side of be followed easily, standing effects of the feet. -this can be noticed by watching owing to our faulty the body weight evenly on the to the correct some method of standing. -with one leg on one leg, or others bear all the weight on the heels, or specific sideways. -heels of the shoes wear out. -and not distributing people do not pay attention stand with the body weight thrown only turned completely on the inner or outer edges where the soles and method of standing feet, we acquire even if the line parallel the hips are contracted, forward. -one feels light in stand with the body weight thrown only on changing; hangs back and the spine feels the strain fatigued and the mind becomes dull. -it is therefore the art of standing feet are kept apart, it to the median plane and the abdomen is better to correctly. -the heels, is pulled in body and the mind acquires keep the heel and toe in a not at an angle. -by this method, and the chest is brought the hips become loose, the abdomen protrudes, the body and consequently we soon feel agility. -we feel the gravity if we essential to master deformities which hamper spinal elasticity. -2. vrk asana one* (plate v rksa means a tree. -2) technique 1. stand in tac;iasana. -1) (plate 2. bend the right leg at the knee and place the left thigh. -rest the foot on the left thigh, toes pointing the right heel at the root of downwards. -3 balance on the left leg, join the palms and raise over the head. -(plate 2) the arms straight 4 stay for a few seconds in the pose breathing deeply. -arms and tadasana . -the right leg and the palms, straighten separate stand again in then lower the . -5 repeat the pose, standing root of the right thigh. -stay for the same length of time on both sides, come back on the right leg, placing to tac;iasana (plate i) and relax. -the left heel at the effects the pose tones the leg muscles and gives one a sense of balance and p01se. -yogasanas, bandha and kriya 63 3 2 3 uttihita trikorjiisana three* (plates 4 and 5) uttihita is a triangle. -means extended, this standing stretched. -asana is the extended triangle pose. -trikona (tri = three; kona = angle) . -. -technique i . -stand in ta asana. -(plate 1 ) 2. inhale deeply and with a jump spread apart the legs sideways 3 to 3! -feet. -raise the arms sideways, palms facing down. -keep the in line with the shoulders, the floor. -(plate 3) arms parallel to 3 turn the right foot sideways to the right, foot slightly knee. -and tightened at the 90 degrees to the right. -keeping the left leg stretched turn the left from the inside 4. exhale, bend the trunk sideways near the right ankle. -if possible, on the floor. -(plates 4 and 5) to the right, bringing the right palm palm should rest completely the right the left arm up (as in the illustration), bringing 5 stretch the right shoulder of the chest and the it in line with and extend the trunk. -the back of the legs, the back in a line. -hips should be gaze at the thumb of the 64 light on yoga 4 5 outstretched the knee-cap and keep the right knee facing the toes. -left hand. -keep the right knee locked tight by pulling up 6. remain in this deeply and evenly. -then lift return to position 2 above. -position from half a minute to a minute, breathing the right palm from the floor. -inhale and 7 now, turn the left foot foot slightly to 2 to 6, reversing posture for the same length of time on the left the left, keep both knees all processes. -sideways 90 degrees to the left, turn the right from position tight and continue inhale and come to position 2. hold the side. -8 . -exhale, and jump, coming back to ta asana. -(plate i) effects this asana tones up the leg muscles, removes stiffness in the legs and any minor deformity in the hips, corrects backaches and neck sprains, evenly. -i t relieves and develops the legs and allows them to develop the ankles strengthens chest. -4 parivr:tta trikorjasana five* (plates 6 and 7) pariv tta this is the revolving trikoj:?.asana. -(plate 4) means revolved, turned round or back. -trikoifa is a triangle. -triangle posture. -i t is a counter pose to uttihita technique y ogasanas, bandha and kriya 65 1 . -stand in ta<;fasana. -spread the legs line with the shoulders, apart sideways (plate 1 . ) -take a deep inhalation 3 to 3! -feet. -raise the arms sideways, and with a jump in palms facing down. -(plate 3) 2. tum the right foot sideways foot 6o degrees to the right, keeping the left tightened at the knee. -90 degrees to the right. -turn the left leg stretched out and 3 exhale, tion (to the right) side of the right foot. -rotate the trunk along with the left so as to bring the left palm on the floor near leg in the opposite direc the outer 4 stretch the at the right thumb. -(plates 6 and 7) right arm up, bringing it in line with the left arm. -gaze 7 5 keep the knees tight. -floor. -remember to rest do not lift the toes of the outer side the right of the left foot well on the floor. -foot from the 6 . -stretch both the shoulders and shoulder-blades. -7. stay in this pose for half a minute with normal breathing. -8. inhale, original lift the left hand from the floor, rotate the trunk back to its position and come back to position 1 . -66 light on yoga 9 exhale, repeat the pose on the left side by turning ways 90 degrees to the left and the right place the right palm on the floor near the outer side of the left foot side foot 6o degrees to the left and the left foot. -10. stay in the pose on both sides for the same length of time, which can be adjusted by doing, say, three to four deep respirations on each side. -i r. after completing position, the time, inhale, raise the trunk back to its original bring the toes to the front and keep the arms as in position 1 . -12. exhale and jump back to tacjasana. -(plate 1.) -this completes the as ana. -effects this asana tones the thigh, calf and hamstring muscles. -the spine and muscles of the back increases the chest is expanded fully. -the pose relieves organs and strengthens vigorates pains in the hip muscles. -are also made to function properly, the abdominal the back, in as the pose the blood supply round the lower part of the spinal region. -5 utthita padvakorjasana four* (plates 8 and 9) parsva means side or angle pose. -flank. -ko a is an angle. -this is the extended lateral technique 1. stand in tacjasana. -(plate 1 . ) -take a deep inhalation and with spread the legs apart sideways 4 to 4i feet. -raise the arms sideways, line with the shoulders, palms facing down. -(plate 3) a jump jn 2. while exhaling slowly, tum the right foot sideways 90 degrees right, and the left foot slightly out and tightened at the knee. -bend the right thigh and the calf form a right angle and the floor. -leg at the knee until the to the to the right, keeping the right thigh is parallel to the left leg stretched 3 place the right palm on the floor by the side of the right foot, the right armpit covering and touching the the left arm out over the left ear. -keep the head up. -(plates 8 and 9) outer side of the right knee. -stretch hamstrings. -4 tighten the loins and stretch the the legs should be in a line and in order to achieve this, move the chest up and back. -stretch every part of the body, concentrating portion of the whole body, specially all the vertebrae is being stretched and ribs move and there is a feeling that even the skin the chest, the hips and and pulled. -on the back the spine. -stretch tbe spine until y ogasanas, bandha and kriya 67 8 9 5 remain in this pose from and evenly. -half a minute to a minute, inhale and lift the right palm from the floor. -breathing deeply 6. inhale, straighten the right leg and raise the arms as in position i. -7 continue cesses, on the left side. -with exhalation as in positions 2 all pro to 5, reversing 8. exhale and jump back to ta9asana. -(plate i ) effects this asana tones up the ankles, in the calves and thighs, waist and hips and relieves peristaltic creases activity develops knees and thighs. -i t corrects defects the chest and reduces fat round the sciatic and arthritic and aids elimination. -pains. -i t also in 68 light on yoga 6. parivrtta piir5vakorjiisana eight* (plates 1 0 and i 1 ) pariyrtta flank. -kox:ta is an angle. -this means revolved, side or turned round or back. -parsva means is the revolving lateral angle posture. -technique 1 . -stand in ta<;iasana. -(plate i) 2. take a deep inhalation, sideways 4 to 4! -feet. -raise the arms sideways in line with the shoulders, and with a jump spread the legs apart palms down. -(plate 3) 3 tum the right foot sideways foot 6o degrees to the right, keeping the left tightened at the knee. -bend the right leg and the calf form a right angle and the right thigh is parallel floor. -90 degrees to the right and the left leg stretched until the thigh at the knee out and to the 10 i i y ogasanas, bandha and kriya 69 4 exhale, and rotate the left arm over the of the right knee, and place the left side of the right foot. -(plates 10 and 1 1 ) trunk and the right knee. -rest the left armpit on the outer side by the outer palm on the floor left leg so as to bring the 5 give a good twist to the spine (to the right), bring the right arm over the right ear (as in the illustrations) gaze up at the outstretched throughout. -trunk and and right arm. -keep the left knee tight turn the 6. hold this pose from half a minute to a minute, breathing and evenly. -trunk and come the arms. -raising the left palm from the floor. -raise the and 2, by straightening back to position and lift inhale, deeply the right leg 7 continue reversing all processes. -with exhalation 3 to 5, on the left side, as in positions 8. in all cases where then on the other the time taken should be this general rule applies here. -the movements are done first on one side and the same in each case. -effects as much as in pariv na one than parivrtta effect. -the hamstrings, trikol)asana. -and that aids digestion. -this pose being a more intensified (plate 6), has a greater stretched are more contracted well round the abdominal thus rejuvenated. -colon without strain. -spinal column, and they are the asana helps to remove waste matter from the organs and the . -. -however, are not the abdominal organs the blood circulates trikonasana ' . -sat! -nor her husband siva, the chief 14) great sacrifice, i three* (plate but he did not invite his of the gods. -threw herself into the fire and but being greatly perished. -tore a hair from his matted locks and 7-virabhad'riisana daksa once celebrated a daughter however, went to the sacrifice, insulted this he was gravely threw it to the ground. -and awaited his orders. -daksa and in the midst of dak a's s.acrifice, routed the other siva in grief for sat! -withdrew sat! -was born again as u:ma in the house of himalaya. -once more for the love of siva and ultimately sat!, and humi iated when siva heard and destroyed and beheaded dak a. destroy his sacrifice. -hero named vlrabhadra gods and priests like a hurricane a powerful vlrabhadra provoked, assembly she strove the and his army appeared won his heart. -the story to kaihis and plunged into meditation. -rose up ' he was told to lead siva's army against l 70 lt"ght on yoga is told by kalidasa of the war-lord). -in his great poem kumiira sambhava (the birth ' this asana is dedicated to the powerful hero created by siva from his matted hair. -technt"que i. stand in ta<;fasana. -(plate i ) 2. raise both arms above the head; stretch (plate i2) up and join the palms. -3 take a deep inhalation ways 4 to 4 feet. -and with a jump spread the legs apart side 4 exhale, turn to the right. -simultaneously 90 degrees to the right and the left foot slightly i 3 ) flex the right knee till the right thigh is parallel the right shin perpendicular to between the right extend beyond the ankle, but should be in line with the heel. -turn the right foot to the right. -(plate to the floor and forming a right angle thigh and the right calf. -the bent knee should not the floor, 1 2 1 3 y ogasanas, bandha and kriya 71 5 stretch out the left leg and tighten at the knee. -6. the face, chest and right knee should face the same right foot, as illustrated. -the coccyx and gaze throw the head up, stretch at the joined palms. -(plate 14) the spine from way as the 14 7 hold the pose breathing. -from 20 seconds to half a minute with normal 8. repeat on the left side as in positions 4 to 6, reversing all processes. -9 exhale and jump ***all standing back to ta<;fasana. -(plate 1 ) poses are strenuous, it should not be tried by persons with a weak heart. -even people who are fairly strong should not stay long in this asana. -this pose in particular. -effects in this pose the it relieves knees and hips. -chest is fully expanded and this helps deep breathing. -stiffness .in shoulders cures stiffness and back, tones up the ankles and of the neck. -it also reduces fat round the 72 light on yoga 8. vfrabhadriisana i 5) i i one* (plate technique r. stand in ta 431 29 301 dro a 49, 251 duj:lkha 24, 26 diirvisisana duty 22, 31, 35f. -dve a 24 495 dysentery 495 dyspepsia ego 20, 44, 49, 51, 438 eka-tattvibhyisa ekigra 36f., 49 ekigrata 49 49 dwi hasta 279 eka hasta 278-9 blood pressure 490 body 19, 21, 24-5> 30, 33f., 36, 38, 4<>- 43, 48, 51f., 58, 1 17f., 434 '. -brahmi 29, so, 135, 159, 237, 302-3 brahma-vidyi brahmacharya brahman 21, 34, 42, 5<>-i, 52, ii7f., 50 31, 34-5, 38, 166, 170 1 30, 189 brahmil].<;ta-prij. -?a brain 490-1 breadnung 21, 24, 27, 36, 44 41-6, 51, 59, 132, 423f., 432ff. -; see also pril].iyima 491 breathlessness bronchitis 491 broncho-pneumonia 491-2 buddhisana 295-6 buddhi 20,36,49,438 34-5 celibacy chakorisana 298-9 chakras 130, 37 8o, 416, 436, 439 chandrasana ardha 74-6 chest 492 chill 492 chitta 20, 44 '., 438 chitta-vik epa 24-6 20, 23-4 chitta-vrtti cleanliness 36, 57, 431 coccyx, pain and displacement 492-3 cold 493 colic 493 colitis 493 compassion concentration 21, 24ff., 36, 45, 48-9, 26ff. -51, i i8f., 436, 461 index 539 head-.stand pose 179-84; see also ek padasana 93-4 urdhva prasarita emotions i9,2 1 , 3 i , 36,45,47, 5 1 ,292, 377. -388, 436 energy 2of.,...35, 37, 39, 43, 45f., i i7, 130, 425, 436, 439 27, 29 enlightenment epilepsy 495 ethics 21, 31, 57 eyes 495 sfrsasana . -headache 498 health 24-5, 37, 5 1 heart 494, 498 heels 498 hernia 498--9 hunch-back 499 hydrocele 499 fatigue 496 fiat-foot 496 496 flatulence food 31-2, 36-7, 47, 57, i i6-17, 431 galavasana 32 5-7 eka pada 327--9 gall bladder 496 gandhi 19, 33 garbha-p ga 141 garudasana 97 496 gastritis gherat:lgasana gher gasana i i 405-8 497 giddiness god 14, 19, 22f., 25f., 30ff., 34ff., 44, 46, 48ff., 6o, 373, 436, 438 i 403-5 r 42 gomukhasana i i 4-16 goraksasana gout 497 as 46-8,50 gut:latita 48, 50 guru 27ff., 43, 50, 437f., 448 halas ana 2 r 6-i 9 parsva 222-3 497 halitosis 'ha.rhsah' 44 haj'!lsasana 284-5 hamstring muscles 497 hanuman 42, 352 hanumanasana 352-4 hastasana pada 91-2 259 ha ha-vidya ha a-yoga 22f., 28, 43, 45 92, 362, 365, 431, 2 3 48, 1 18, 288 iga 273, 439, 443 imagination immortality impotence 499 499-500 indigestion individuality indriya-jaya insomnia 500 intellect 23, 44, 5 1 36 5 1 , 438 501 ntestines isvara-prat:1idhana 36, 39-40 19f., 22, 26, 29, 35f., 39f., 49, 50 jagrata-avastha janaka 276 japa 436 jaya 441 jivana-mukta 52 1 1 8 ]lvana-mukti jivatma 19, 44 450 pranayama 450 kaivalya 3 1 kama 295, 439 kama-n1pa 439 kandasana 348-52 kapalabhati kapalabhati kapila 42 296 kapilasana kapinjalasana kapotasana 367-72 karma 52 karma-marga 22 karma-yoga 20 220-i kart:iapidasana kartikeya 158, 294 karuna 26f. -kasyapa 311-12, 356 408--9 540 index 20, 26, 29f. -3ii-i3 kasyapasana kap:topani ad kidneys soo klesa 23 knees 500-i konasana baddha i28--9, 432 supta 22i-2 upavi a i63-5 3 30 kow:<;iinya kow:c_tinyasana dwi pada 33o-2 eka pada i 332-4 eka pada ii 334-{) 19, 2i, 29, 36, 52 krislu)a k kara 45 krounchasana ksipta 48 kukku!asana arsva 322-5 urdhva 32o-2 i4o-i i 5 8---9 kumbhaka 43-4, ii8, 432, 435-{), 437, 447f. -an tara 43,435,437, 442, 444f., 447f., 452ff., 456f., 459, 46i bahya 43, 435, 437, 442, 447, 453f., 46i kevala 46i kw:<;ialini kiirmasana 288--9i i30, 273, 439-40 supta 29i-2 439 madhyama 27 maitri 26f. -i oo makarasana malasana i 262-{) malasana ii 266-7 manas 20, 27, 45, 49f., ii8, 424, 438f. -manas-chakra mai:t<;ialasana 38i-4 mat?ipiiraka-chakra man omani i i 8 mantra-yoga mar1chyasana marichyasana marichyasana marichyasana i 38-40 matsyasana 259 matsyendra matsyendrasana 27 i 15 i ii 161-2 iii 254-7 iv 2 57-9 380, 439 ardha i 25 2 ardha ii 27o-i ardha iii 271-3 paripiir a 273-{) 282-4 mayiirasana eka pada uttana 229-30 padma 284 pincha 285-7 uttana 227---9 u ttana padma 2 3 i -4 meditation 21f., 25, 5 1-2, 120, 129f., 46i memory 49i menstrual meruda <;ta migraine 502 mind 19f., 27f., 30, 33f., 38ff., 44ff., disorders 437, 439 502 48f., s8, 93, u8-i9, 292, 377f., 403, 422ff., 434f., 438 439 372-3 see nauli labour pain soi laghuvajrasana laksmi288 lala;a-chakra lauliki, laya u 8 laya-yoga legs 50 i , 504-5; deformity in 494 liver 496, 501 lobha 39 lola sana i i 6 lotus posture 129-30; 28 see also padm asana lumbago 501 lungs 501 45 mindlessness moderation 20, 27, 29 moha 39 mok a i9, 423-4 morality 3 1, 33 mrdu 27 miidha 48 mudita 26f. -mudra asvini 438 jiiana 433, 441, 456, 458 khecharl i i 8-i 9 maha i47-8 parailgmukhi sanmukhl i32-3 yoni i32 mudrasana yoga i44 i 32 mukhottanasana tiriang 4i8-i9 4i6, 439 miiladhara-chakra . -. -prar:aayama nada n8-i9 nadr u7, 273, 38o, 436, 439, 445 432, 445-8 na41 sodhana naga 45 nakrasana ios-7 names, sacred 436 nasal catarrh 502 natarajasana 4i9-22 nauli 426-8 navasana ardha i i 2-i 4 paripiirna 502 i 11-12 nervous debility 'neti neti' 52 nirailjana nirodha 20 niruddha 49 niyama 2i, 36, 57, 1 1 6 31-2, 38, 47 non-violence 1 1 8 obesity 502 89-90 padangu !hasana supta 244--6 utthita hasta 76-8 padasana a 409-ii 240-2 urdhva prasarita u ttana 248-9 padmasana i29-32, 432 baddha i42-4 padmottanasana ardha baddha 94-7 padottanasana prasarita prasarita i 8i-4 i i 84-5 pain 23f., 26, 3 i , 36, 38, 48 index 541 502-3 palpitation pancreas soi paralysis 503 paramapada i 1 8 paramatma 19, 2 i , 44 parighasana parivartanasana 8 5-7 ja hara 237-40 parsvakonasana . -68-9 pariv tta utthita 66-7, 76 78-8o parsvottanasana parvati 259 i25--6 paryankasana pasasana 267-70 paschimottanasana i 5 3--6 i66-7o ardha baddha padma parivrtta i7o-3 triang mukhaikapada l.jrdhva mukha i 173-4 urdhva mukha i i i74--6 uttanasana 59 156-7 pataftjali 19ff.,, 26ff., 3 i , 34, 36, 46i peace 20, 27, 30, 36, 37-8, 44, 52, 133, 436 piles 503 p c;ia-pra a 44 pindasana garbha 14i-2 pitigala 273, 439, 443 23 pleasure 503 pleurisy pneumonia 503 polio 503 posture 2 1 , 36, 40-3, 432f. -; see also as ana practice 2 i , 26, 28ff., s8, 6o, 432, 3i2 434f. -prajapati prakrti 46 prarnada 28f. -prama a 23 pr a 27, 42f., 44f., so, 118, 130, 423-4. -425, 436f., 443, 461 45 prana-vayu pra va 50 59, pranayama 2 i , 27, 36,43-5,48, so, 43i--61 120, i29, 542 index pratiloma pral)ayama 458-61 pracyahara 21, 25, 45-8, so, 133, 292, 436 pratyaksa 23 prayer 27, 38, 44 prostates pw;tya 26 puraka 44, 434-f., 437, 441, 444, 446, 503-4 453f. -piirnata 40 r 76-7 piirvottanasana raga 23 raja-yoga 22f., i r8 rajakapotasana 397--9 eka pada i 389--9i eka pada ii 392-3 eka pada iii 393-4 eka pada iv 394-5 eka pada setu bandha 229-30 niralamba i 2i4-15 niralamba ii 2is-i6 parsva 226-7 parsva pindasana in 2 34-5 parsva urdhva padmasana in 23i, 236 parsvaika pad a 22 5-6 pin<;iasana in 234 salamba i 205-i3 salamba ii 2 i4 setu bandha 227-30 urdhva padmasana in 23o-i ' sati 69, 420 sat tva 46-7, 50 sattva- a 48f. -savasana 59, 422-4, 435 sayanasana 286f. -504 sciatica . -50 rajas 46f., rajo-guna 47f. -rama 352 reason 2o, 22, 30, 33, 44f., 5if. -rebirth 30 rechaka 44, 435, 437, 442, 444, 446, self zotf., 24, z6f., 29f., 33, 36, 38 , 40, 49f., i i 7f. -23, 3 i self-surrender senses zotf., 25, 28, 30, 36,39-40, 44ff., 5 1 , 1 18, i33, 292, 423, 433-4, 436 453f. -relaxation 422-3, 432 renunciation 3 i , 35 rheumatic pains 504 ruchikasana 30i-2 sacred words 436 sadhana 26, 29-30, 3 i sahajavastha i i 8 380, 439 sahasrara-chakra sahita pranayama 461 salabhasaria 99-ioo vipari:ta 4i6-i8 354-6 samadhi 2i, 3 i , 52, i i7f., 436 samakol)asana samana 45 sambhava i 32 sarhsaya 24f. -29 sarhskara sankaracharya 44 santosa 36, 37-8 sarvangasana eka pada 223-5 57ff., 205-20 ' . -siddha 1 r6-i8 siddhasana 1 16-zo, 432 sil!lhasana i i 35-6 simhasana ii i 37-8 sir asana 57ff., 1 79-205 baddha hasta 193-5 dwi pada 307-8 eka pada i99-201, 292-4 janu 148-5i mukta hasta i95-7 parivrtta janu pariv naikapada 198--9 parsva i 97-8 parsva d rdhva padmasana in 203 parsvaika pada 202-3 pindasana in 205 salamba i 179-84 salamba ii 1 2 salamba iii 192-3 urdhva padmasana in 203 151-3 srta 276, 352 sitakarr pranayama 452-3 sitait priil)iiyama 451-2 siva so, 69-70, 132,259,294-5, 296f., turiyavastha so, i 17f. -index 543 ' 294-5 346, 419-20 skandasana 'so'ham' soka 39 soul 19, 21, 30, 39f., 42f., 52f., 1 1 7-18, 423-4, 440; conditions of 1 17-18 44 ' 504 of 495 sound, inner 1 1 9 spermatorrhoea spinal discs, displacement spleen 501 sraddha 29 sterility 504 so, 292 sthita-prajiia tumour of 505 stomach, styana 24-f. sunyasiinya 1 1 8 siirya 1 59, 3 1 2 siirya bhedana pr ayama 443-5 siirya-chakra 439 siirya-na i su umr;ta na i 130, 437, 439 su upti-avastha svadhi hana-chakra svadhyaya svanasana 380, 416, 439 36, 38-9 so, 1 1 7 443 adho mukha 59, 1 1o-1 1 urdhva mukha 108-9 so svapnavastha svasa-prasvasa 24 tadasana 61-2 tamas 46f., so tamo-glll)a 47f. -tapas 36, 38 'tat twam asi' 51 30 tattva-jiiana tittibhasana 308-9 tolasana 134-5 505 tonsillitis trikonasana 65-6 parivrtta utthita . -63-5 t rivikramasana supta 356-7 tr r;ta 48 tuberculosis 505 441-3 5 1 , 1 1 8 udana 45 ujjayi 441 ujjayi prar;tayama ulcers 505 upani ads upek a 26f. -iirdhva-retus urine sos-6 u asana 87-8 uterus, 88-9 utka asana 92-3 uttanasana 438 displacement of 494-5 vachika 38 vairagya vajrasana 21, 28, 48 supta 146-7 veins so6 391-2 i 346-7 ii 347-8 valakhilyasana vamadevasana vamadevasana vamana 356 varicose vasanta 295 vasigha 42, 309-io, 313, 330 309-1 i vasi ;hasana vatayanasana 98-9 vayu 45, 437 vegetarianism vibhiiti-pada vikalpa 23 viloma prar;tayama viparyaya i 69-71 virabhadrasana i i 7 1 -3 virabhadrasana iii 73-4 virabhadrasana i 302-4 viranchyasana ii 304 viranchyasana 1 2o-3, 432 virasana 32, 37 3 1 455-7 23 supta 1 23-5 virtue 26-7, 35 virya 25 visnu so, 135, 138, 158, 237, 246-7, 288, 301, 305, 352, 356 visuddha-chakra visvamitra 42, 310, 313, 325 313-15 visvamitrasana 380, 416, 439 544 index vrk asana 62 adho mukha 287 i 386 vrschikasana v rschikasana ii 3 86-8 vrtti 20 vrtti pra ayama sarna 453-4 vi ama 454-5 vyana 45 will 14, 39-40, 5 1 work 22 yama 2 1 , 3 1 , 36, 57, n6 yoga siitra i 9f., 22, 3 i 340-3 yogadandasana y oganidrasana 304-7 yukta 19 . -. ) -( ) c ;\ i i i e " lt i i $ i 8 . -o o light on yc>ga has become the bible for hundreds of thousands of people who practic'e yoga daily with the iyengar method, for ex< rcisr, medita tion. -or simpl) rrlaxation. -with more than 600 photographs depicting all the postures and breathing exercises, it remains the fullc t, most practical, and most profusely illustrated guide by the world's foremost yoga teacher. -light on yoga is a comprehensive and definitiv e source book for the initiated, as well as the best introduetion for tlw novice who seeks tht' healthful benefits of yoga for mind, body, and sou i. -"[yoga] is a technique ideally sui ted to prevent physical and mental illi1ess and to protect the body generally . -. -. -. -by its very nature it is inex tricably associated with universal la\\is: for respect for l i fe, truth, and patience are all indispensable factors in the dra\\-ing of a quiet breath, in calmness of mind and firmnes of will. -this book '"ill serve to spread this basic art and will ensure that it is practiced at its highe t level." --yehudi menuhin b.k.s. -iyengar, for whom h undreds of iyengar lnstitutes all over the world arc named, heads his own institute in i ndia. -cm en des i(,;\ m c.\l\ l'i chl 'cuo<: <..e'\ books. -:\ t:w 't ork ,;95 pnu\teo 111, the l a. c, 199-1 r-\1\ oom house. -be. -i s b n 0 - 8 0 5 2 - 1 0 3 1 - 8. - -Book3: -perspective the energy balance model of obesity: beyond calories in, calories out kevin d hall,1 i sadaf farooqi,2 jeffery m friedman,3 samuel klein,4 ruth jf loos,4,5 david j mangelsdorf,6 stephen o rahilly,2 eric ravussin,7 leanne m redman,7 donna h ryan,7 john r speakman,8 and deirdre k tobias9 1national institute of diabetes and digestive and kidney diseases, national institutes of health; 2wellcome-mrc institute of metabolic science, university of cambridge; 3the rockefeller university; 4washington university school of medicine in st louis; 5novo nordisk foundation center for basic metabolic research, university of copenhagen; 6university of texas southwestern medical center; 7pennington biomedical research center; 8shenzhen institutes of advanced technology, chinese academy of sciences, shenzen, china, and the university of aberdeen, aberdeen, united kingdom; and 9brigham and women s hospital and harvard medical school abstract a recent perspective article described the carbohydrate-insulin model (cim) of obesity, asserting that it better reflects knowledge on the biology of weight control as compared with what was described as the dominant energy balance model (ebm), which fails to consider biological mechanisms that promote weight gain. -unfortunately, the perspective conflated and confused the principle of energy balance, a law of physics that is agnostic as to obesity mechanisms, with the ebm as a theoretical model of obesity that is firmly based on biology. -in doing so, the authors presented a false choice between the cim and a caricature of the ebm that does not reflect modern obesity science. -here, we present a more accurate description of the ebm where the brain is the primary organ responsible for body weight regulation operating mainly below our conscious awareness via complex endocrine, metabolic, and nervous system signals to control food intake in response to the body s dynamic energy needs as well as environmental influences. -we also describe the recent history of the cim and show how the latest most comprehensive formulation abandons a formerly central feature that required fat accumulation in adipose tissue to be the primary driver of positive energy balance. -as such, the new cim can be considered a special case of the more comprehensive ebm but with a narrower focus on diets high in glycemic load as the primary factor responsible for common obesity. -we review data from a wide variety of studies that address the validity of each model and demonstrate that the ebm am j clin nutr is a more robust theory of obesity than the cim. -2022;115:1243 1254. keywords: obesity, food intake, energy balance, carbohydrates, insulin introduction theoretical models of the pathogenesis of obesity can help organize and synthesize observations to form hypotheses for experimental interrogation. -the results of such experiments can be used to refine or refute models, thereby leading to a better understanding of the mechanistic drivers of common obesity. -therefore, an evidence-based model that increases our understanding of the factors responsible for obesity can be used to design more effective interventions for obesity prevention and therapy. -two important questions regarding human obesity should be addressed by a successful model. -first, what explains between- person variability in adiposity in a population? -second, what explains the global shifts in the population prevalence of obesity over the past several decades? -as a partial answer to the first question, bmi is highly heritable and genetic differences explain 75% of bmi variability among individuals (1, 2). -regarding the second question, although changes in occupational physical activity and the built environment might have contributed to obesity by reducing overall physical activity (3), changes in the food environment are likely the primary driver of the increased obesity prevalence in recent decades (4). -however, the specific aspects of the food environment that are most obesogenic and how they interact with the genetics of susceptible individuals to cause obesity are topics that are hotly debated, and competing theoretical models implicate different mechanisms. -a recent perspective article described the theoretical (cim) of obesity, asserting carbohydrate-insulin model this work was supported by the intramural research program of the national institutes of health, national institute of diabetes and digestive and kidney diseases. -dkt is the academic editor for the american journal of clinical nutrition but played no role in the evaluation of this manuscript. -address correspondence to kdh (e-mail: kevin.hall@nih.gov). -peptide; cim, agrp, abbreviations balance model; fto, glucagon-like carbohydrate-insulin model; ebm, fat mass obesity-associated peptide 1. agouti-related energy gene; glp-1, used: and received december 13, 2021. accepted for publication february 2, 2022. first published online february 4, 2022; doi: https://doi.org/10.1093/ ajcn/nqac031. -am j clin nutr 2022;115:1243 1254. printed in usa. -published by oxford university press on behalf of the american society for nutrition 2022. this work 1243 is written by (a) us government employee(s) and is in the public domain in the us. -1244 hall et al. -that it better reflects knowledge on the biology of weight control as compared with what the authors described as the dominant energy balance model (ebm), which was claimed to conceptualize obesity without considering the biological mechanisms promoting weight gain (5). -in doing so, the authors presented a false choice between the cim and a caricature of the ebm as a theory of obesity that does not reflect modern obesity science. -indeed, the recent perspective conflated and confused the principle of energy balance, a law of physics that is agnostic to obesity mechanisms, with the ebm as a theoretical model of obesity. -the perspective described the ebm as an inherent tautology that considers all calories to be metabolically alike for all practical purposes (5). -these statements more aptly refer to the law of physics and not the ebm as a theoretical model that is firmly based on biological mechanisms. -to be clear, all theoretical models of obesity, including the cim, must satisfy the principle of energy balance to avoid violating the laws of physics. -the perspective also described a straw-man version of the theoretical ebm postulating that energy-dense, tasty, modern processed foods drive a positive energy balance through increased intake under conscious control (5). -however, this is an inaccurate description of the ebm, which we clarify below. -we also describe the recent history of the cim and show how its latest most comprehensive formulation (5) constitutes abandonment of its formerly central feature (6 9) and can be considered as a special case of the ebm that focuses on diets with high glycemic load as the primary factor responsible for obesity. -we review data from a wide variety of studies that address the validity of each model and demonstrate that the ebm is a more robust theory of obesity than the cim. -the ebm of obesity the ebm proposes that the brain is the primary organ responsible for body weight regulation via integration of external signals from the food environment along with internal signals from peripheral organs to control food intake (figure 1) (10). -specific brain regions, such as the hypothalamus, basal ganglia, and the brainstem modulate food intake below our conscious awareness via complex endocrine, metabolic, and nervous system signals (11 13) acting in response to the body s dynamic energy needs as well as environmental influences (14, 15). -the orchestration of energy homeostasis occurs through short-term signals [e.g., ghrelin, peptide yy, glucagon-like peptide 1 (glp-1), vagal afferents] controlling meal patterns (i.e., the initiation and cessation of feeding) and long-term signals (e.g., leptin) that modulate the activity of the short-term system thereby increasing or decreasing overall energy intake. -thus, whereas day-to-day energy intake and energy balance of an individual can be highly variable, neural regulation of energy balance is generally achieved over prolonged time scales (16 19). -the ebm proposes that the increasing population prevalence of obesity in recent decades is primarily due to changes in the food environment, including increased availability and marketing of a wide variety of inexpensive, convenient, energy-dense, ultraprocessed foods that are high in portion size, fat, and sugar, and low in protein and fiber. -the cim perspective downplayed the potential role of conscious liking or palatability of food in driving obesity (5). -however, palatability is only 1 dimension of the multifaceted concept of food reward that involves incentive salience, wanting, and motivation that primarily operate below our conscious awareness (11). -brain circuits controlling energy intake respond to a changing food environment in ways that are beginning to be elucidated, especially in mouse models (20, 21). -for example, a bidirectional circuit was recently identified between hypothalamic neurons expressing agouti-related peptide (agrp) that control homeo- static hunger and the midbrain dopamine system influencing food reward (22). -exposure to a high-fat diet alters the activity of this bidirectional circuit and results in excess energy intake, development of obesity, and devaluation of a low-fat diet that does not induce obesity (23). -distinct gut-brain pathways have been identified for sensing dietary fat and carbohydrate thereby modulating hypothalamic agrp neuronal activity (24) and striatal dopamine release (11). -therefore, the ebm is consistent with the idea that diet composition, not simply its caloric content, could be an important factor in the central nervous system control of food intake. -the physical principle of energy balance does not specify the biological mechanisms determining how energy imbalances are partitioned within the body to result primarily in changes in adipose tissue fat stores compared with changes in energy stored or utilized in other body compartments a fact that has been recently misinterpreted as being a deficiency in the ebm (25). -however, based on extensive studies of human macronutrient balance in response to various dietary interventions (26 34), the ebm incorporates physiological mechanisms underlying energy partitioning whereby diet composition and amount affect whole- body net oxidation rates of carbohydrate, fat, and protein such that overall energy imbalances are primarily reflected as fat imbalances regardless of the composition of the diet (35 37). -this regulation of macronutrient metabolism is the consequence of coordinated control of multiorgan metabolic fluxes by a variety of hormones, including but not limited to insulin, such imbalances end up primarily reflected that whole-body fat as changes in adipose tissue fat storage (38 40). -the ebm therefore conceptualizes adipose tissue as an active endocrine organ evolved to dynamically coordinate the efficient storage and mobilization of energy (i.e., triglycerides) in response to energy surplus and deficit, respectively. -the ebm recognizes that individual differences in energy partitioning can result in different degrees of adiposity, even when energy intake is not different (41, 42). -this can happen, in part, because accretion of lean body mass results in greater energy expenditure as compared with accumulation of body fat mass. -indeed, energy partitioning differences explain why females accumulate greater body fat than males during growth and development despite consuming fewer total calories (43). -also, body fat mass can be relatively constant or even decrease during periods of rapid growth when positive energy balance corresponds to increasing lean body mass (44). -furthermore, subtle differences in adipose tissue dynamics may affect energy partitioning and fuel utilization thereby influencing body compo- sition over the long term (45 49), but the extent of such influences on common obesity are currently unclear. -the ebm allows for a role of decreased physical activity in the development of obesity, although not necessarily because of energy balance model of obesity 1245 figure 1 the energy balance model of obesity posits that body weight is regulated by the brain in response to external signals from the food environment that are integrated with internal signals to control food intake below our conscious awareness. -increased prevalence of obesity has resulted from changes in the food environment leading to increased food intake and circulating fuels. -hormones, including insulin, respond to nutrient intake and absorption to direct the flow of metabolic fluxes into and out of various organs and provide signals to the brain that control food intake. -energy supply to organs such as liver and muscle increases, which supports their increased growth during the development of obesity and can result in ectopic lipid accumulation. -signals indicating the energy status of various organs are sensed by the brain to control food intake by mechanisms that remain to be fully elucidated. -oxidation of carbohydrate, fat, and protein provides the body with its energy needs, which increase as obesity develops. -adaptations of metabolic fuel selection as well as changes in the endocrine milieu ensure that partitioning of overall energy imbalances are primarily reflected as changes in adipose tissue triglyceride storage regardless of diet composition. -inherited variation in the operation of these processes, particularly those in the brain, are responsible for a substantial proportion of the interindividual difference in susceptibility or resistance to developing obesity in a particular environment. -thick blue arrows indicate the flow of energy. -gi, gastrointestinal. -decreased energy expenditure per se but rather due to decreased precision of energy intake control (3, 50, 51). -furthermore, other factors can also play a role in the development of obesity within the ebm framework (52). -the above description of the ebm is inconsistent with the characterization by ludwig et al. -(5) in their perspective and the biological elsewhere (7) as a theoretical model that essentially disregards influences on fat storage, knowledge about proposing that obesity results from conscious control of behaviors affecting energy intake or expenditure. -indeed, the ebm emphasizes that powerful internal and external signals influence the neural regulation of energy balance below our 1246 hall et al. -conscious awareness and explains why simple advice to eat less and move more is ineffective for sustained weight loss. -the cim of obesity the cim presented in the recent perspective (5) is substantially different from its previous iterations (6 9). -box 1 provides a brief history of related theoretical concepts leading to taubes 2007 proposal (9) of the adipocentric cim whereby obesity results from increased dietary carbohydrates driving excess insulin secretion causing adipose tissue to accumulate and trap fat thereby starving nonadipose tissues of fuel. -thus, by driving fat accumulation, carbohydrates also increase hunger and decrease the amount of energy we expend in metabolism and physical activity (9) thereby resulting in positive energy balance with energy intake exceeding expenditure. -taubes justified his adipocentric cim by asserting that by the mid-1960s four facts had been established beyond reasonable doubt: 1) carbohydrates are singularly responsible for prompting insulin secretion; 2) insulin is singularly responsible for inducing fat accumulation; 3) dietary carbohydrates are required for excess fat accumulation; and 4) both type 2 diabetics and the obese have abnormally elevated concentrations of circulating insulin [emphasis added] (9). -to explain the epidemiological obser- vations of the emergence of obesity in recently westernized populations taubes stated that, carbohydrates, and particularly refined carbohydrates and perhaps the fructose content as well, and thus the amount of sugars consumed are the prime suspects in chronic elevation of insulin; hence, they are the ultimate cause of common obesity (9). -unfortunately, the foundational facts of the adipocentric cim are in error, particularly the claims of singularity and necessity about the roles of insulin and dietary carbohydrates on adipose tissue fat metabolism. -rather, adipose fat storage can oc- cur in the absence of either dietary carbohydrate or an increase in insulin above basal concentrations (38, 53, 54). -thus, alternative physiological mechanisms allow body fat to be stored without the necessity of dietary carbohydrates a feature of adipose tissue that likely had evolutionary advantages for omnivorous species. -furthermore, insulin secretion is determined by a variety of fac- tors beyond dietary carbohydrate (55 57). -indeed, basal insulin concentrations are similarly affected by overall energy imbalance regardless of whether the imbalance is achieved by manipulating dietary carbohydrates or fat (58). -thus, there are potentially many paths to fat accumulation despite taubes believing it to be an inescapable conclusion that by stimulating insulin secretion, carbohydrates make us fat and cause obesity (9). -despite problems with the foundational logic of the adipocen- tric cim, it was adopted more widely (6 8) with an emphasis that this model considers fat cells as central to the etiology of obesity such that a high-carbohydrate diet produces postprandial hyperinsulinemia, promotes deposition of calories in fat cells instead of oxidation in lean tissues, and thereby predisposes to weight gain through increased hunger, slowing metabolic rate, or both (7). -accordingly, a popular diet book based on the adipocentric cim claimed that insulin acts as the ultimate fat cell fertilizer that ushers calories into fat cells, but restricts their passage back out , and consequently our fat cells make us overeat. -(6). -based on observations that insulin rapidly responds to changes in dietary carbohydrate and has expeditious effects on adipose tissue, readers were advised that decreasing carbohydrate is the quickest and easiest way to lower insulin and jump-start weight loss and low-carbohydrate diets result in big declines in hunger, sometimes as early as day 1 (6). -box 1 historical antecedents of the adipocentric cim in the early 20th century, the idea of lipophilia proposed adipose tissue was the primary site of dysregulation in obesity, although dietary carbohydrate-driven insulin secretion was not implicated in this pathophysiology (143). -in the early 1950s, pennington (144 148) proposed that people with obesity have a cellular defect in their ability to oxidize carbohydrate that resulted in increased de novo lipogenesis, suppression of adipose lipolysis, and thereby resulted in body fat accumulation along with reduced energy expenditure and increased appetite. -although such a cellular defect was never found, pennington speculated that dietary carbohydrate-driven insulin secretion exacerbated the problem, which helped explain the apparent effec- tiveness of his low-carbohydrate diet regimen for treating obesity. -in 1962, astwood (149) expanded on the lipophilia concept by hypothesizing that increased appetite in some people with obesity could be due to aberrant action of insulin, cortisol, or other hormones to either trap fat in adipose tissue or prevent fat oxidation in peripheral tissues. -beginning in the mid-1970s and extending into the late 1990s, mark friedman (150 153) proposed that energy sensing in peripheral tissues, especially the liver, provides the primary signals to the brain controlling energy intake and noted that diets high in both fat and carbohydrate could be responsible for obesity due to aberrant fuel partitioning to adipose tissue leading to a decrement in liver energy status (150). -in the early 2000s, ludwig (75, 154) hypothesized that overeating is the result of consuming high-glycemic-index foods that rapidly increase plasma glucose and insulin, resulting in uptake of nutrients in insulin-responsive tissues and subsequent decreases in circulating fuels in the late postprandial period that are sensed by the brain to promote hunger. -in 2006, lustig (155) linked increasing population obesity prevalence to our current western diet [that] is highly insulinogenic, as demonstrated by its increased energy density, high fat content, high glycemic index, increased fructose composition, decreased fiber, and de- creased dairy content. -lustig proposed that autonomic dys- function potentiates diet-induced hyperinsulinemia, which was hypothesized to increase energy intake by antagonizing leptin signaling and increasing dopamine in the brain. -neither ludwig nor lustig emphasized a primary role of adipose tissue insulin signaling in their models of obesity. -rather, insulin was presumed to act on multiple organs in parallel, and the brain played a direct role in controlling energy intake either by sensing low concentrations of circulating fuels (75) or by altered central leptin and dopamine signaling as a result of hyperinsulinemia (155). -energy balance model of obesity 1247 precisely how carbohydrate-driven insulin action on adipose tissue drives hunger or slows metabolic rate is not specified by the cim, but low concentrations of circulating fuels in the late postprandial period after high- compared with low-glycemic- load meals have been proposed to be either sensed directly by the brain or via decreased energy status of peripheral organs like the liver. -of course, dips in blood glucose can increase hunger by mechanisms independent of those proposed by the cim as described long ago in the glucostatic theories of mayer (59, 60), lemagnen (61), and campfield (62, 63). -indeed, greater dips in blood glucose occurring 2 3 h after meals were recently associated with increased appetite in humans (64). -the adipocentric cim was expanded beyond dietary car- bohydrates and a comprehensive paradigm was proposed whereby all obesogenic factors (e.g., amount of dietary pro- tein, micronutrients, poor sleep, stress, physical inactivity, and environmental endocrine-disrupting chemicals) affect insulin secretion or adipocyte biology directly with increased energy intake and decreased energy expenditure as necessary down- stream consequences (7). -hence, the adipocentric cim achieves the much-touted reversal of the direction of causation whereby positive energy balance does not cause increasing adiposity; rather, a shift in substrate partitioning favoring fat storage drives a positive energy balance (5). -abandonment of the adipocentric cim some of us (jrs and kdh) recently argued against the adipocentric cim and suggested that insulin and other factors exert pleotropic actions on a variety of organs that influence energy balance (10). -interestingly, the latest formulation of the cim (5) also de-emphasizes the formerly central role of adipose tissue and thereby abandons the comprehensive paradigm of the adipocentric cim (7). -the new cim considers that substrate partitioning and fat deposition are determined by the together with other hormones integrated actions of insulin, just adipose and autonomic inputs, tissue (5). -unfortunately, the proposed mechanisms involved in this integrated, multiorgan, multihormone cim remain unclear, including the mechanisms of internal starvation of nonadipose tissue and how this is sensed during the development of obesity. -in multiple organs, not importantly, despite continued claims that the new cim proposes a reversal of causal direction (5), this is no longer a necessary feature because all pathways to positive energy balance are not required to act downstream of adipose tissue fat accumulation. -indeed, the new cim proposes the existence of parallel pathways influencing energy balance, but it is unclear exactly what these pathways are or how they might work. -one such pathway involves a direct effect of dietary glycemic load on energy intake, presumably mediated by the brain (5). -if this new direct pathway linking high-glycemic-load diets to increased energy intake dominates the proposed indirect effect downstream of adipose tissue, then the new cim results in the usual causal direction of increased energy intake leading to adipose tissue fat accumulation. -in that case, the new cim can be considered an oversimplified version of the ebm with a focus on glycemic load as the main driver of excess energy intake. -evaluation of the ebm and cim although data might support various aspects of both the ebm and cim, a valid model should withstand tests of its various predictions or be suitably modified or abandoned. -most importantly, theoretical models of obesity must explain between- person variability in adiposity as well as the recent global shift in its distribution. -below, we describe a wide body of evidence with implications for the validity of the cim and ebm as plausible models that explain the heterogeneity of adiposity and the obesity pandemic. -rodent studies rodent models are valuable for testing hypotheses of diet and body weight regulation because they are amenable to rigorous control of diet for extended periods and independent of potentially confounding factors such as the conscious desire to lose weight. -moreover, responses of different rodent strains to variable macronutrients in the diet can provide insights into the regulatory systems involved. -however, the high level of control comes at the cost of questionable translational relevance to human obesity (10). -for example, rodent studies have been critical in demonstrating the causal role of insulin affecting aspects of metabolism, food intake, and fat deposition (65 71); however, this evidence does not discriminate between ebm and cim because both models recognize the importance of these processes (10). -conversely, other rodent studies show that the role of dietary carbohydrates in determining body weight, as postulated by the cim, is largely untenable. -most standard laboratory rodent diets are high in carbohydrates. -typical mouse unpurified diet ( chow ) consists of 70% carbohydrate, 10% fat, and 20% protein (by energy), which does not induce obesity. -shifts in the macronutrient distribution towards lower percentage carbohydrate and higher percentage fat, with protein constant, induces obesity in many strains, with a peak effect on body fatness observed at 20% carbohydrate, 60% fat, and 20% protein (72, 73). -although it has been argued that this is because the carbohydrates in such diets are not high-glycemic-index carbohydrates (74), this is incorrect. -the main carbohydrate components of commercial mouse unpurified diet are corn starch, maltodextrin, and sucrose (75), which all have roughly equivalent glycemic indices in rodents (76). -even if one focuses on sucrose alone, feeding mice a diet with 73% calories as sucrose (82% of calories as carbohydrates, 8% as fat, and 10% as protein) was protective against obesity (77), consistent with the lower body weight gain of rats on a 51.3% glucose diet (by weight) (74). -alternative explanations for these findings include potential confounding by higher intakes of sfas by rodents fed low- glycemic-index diets, such that saturated fats induce insulin resistance, hyperinsulinemia, and subsequent obesity (5, 74). -as such, this argument underscores the importance of dietary factors other than carbohydrate per se in the pathogenesis of obesity, emphasizes the ability of some strains to resist diet- induced changes in fat storage, and directly refutes the notion that dietary carbohydrate is the main driver of body fat accumulation as proposed by the cim. -1248 human genetics hall et al. -the ebm implicates the brain as the primary organ responsible for obesity whereas the cim implicates adipose tissue. -given the high heritability of obesity, the relative expression of common obesity genes in different organs provides evidence regarding the relative validity of these models. -other than rare mutations in the leptin gene that result in obesity due to the inability of the brain to sense adequate body fat stores, no genetic disorder primarily affecting the adipocyte or enhanced insulin action has been reproducibly reported to cause obesity. -humans who have homozygous mutations in genes encoding adipose triglyceride lipase (atgl) or comparative gene identification-58 (cgi58) have a severe defect in adipocyte lipolysis yet do not develop obesity (78, 79). -nevertheless, adipose-enriched genes include variants influencing body fat distribution and features of the metabolic syndrome, such as insulin resistance (80). -given that nervous systems have evolved to control energy intake (81), it is not surprising that every known monogenic disorder that causes human obesity involves a gene intimately involved in the control of energy intake by the hypothalamus (82). -furthermore, unbiased genome-wide association and gene expression studies have determined that variations in total adiposity between people are primarily due to differences in genes that are most highly expressed in the brain (82 84). -for common variants, their effects on fat mass are so small that it is hard to definitively establish the impact of each individual variant on food intake, energy expenditure, or energy partitioning. -an exception is the common variant with highest effect size, the fat mass and obesity-associated (fto) gene, where carriers of the risk allele have consistently been reported to have increased appetite and/or objectively measured food intake (85, 86). -epidemiological studies there is heterogeneity both in the mean bmi among regions globally, by sex, and national income, and in bmi trends observed from 1980 to 2008 (87). -the worldwide obesity epidemic has been attributed in large part to shifting toward industrialized western diets (88, 89), characterized by refined grains, processed oils, sugar-sweetened beverages, animal products, and low in- takes of nonstarchy vegetables and whole grains. -global trade and improved technologies have facilitated the rapid dissemination of food commodities both intentionally, to address crises of undernutrition, and via stealth expansion of the food industry (88 91). -these have led to declines in whole grains, vegetables, and legumes, replaced by increases in caloric sweeteners and refined oils in the form of processed foods. -despite such notable shifts in diet quality, us trends of average adult food intake indicate a remarkable stability in the macronutrient composition of calories from carbohydrate, fat, and protein (92). -further, whereas added sugar from foods has also been stable, its intake from beverages underwent a significant increase in the first half of the obesity epidemic (93). -since around 2000, modest improvements in diet quality have been observed, such as substituting from refined back to whole grains and a reduction in sugary beverages (94). -global validated physical activity data are sparse relative to nutrition. -there was an increase in the portion of the global population living in urban compared with rural areas, from 41% to 55% over 1985 to 2014 (95), suggesting a role for a sedentary lifestyle in obesity; however, an analysis from the ncd risk factor collaboration indicated many countries experienced greater increases in bmi in rural rather than urban areas, suggesting trends in urbanization alone are insufficient to explain global obesity trends (96). -overall, the accumulated trend data implicate a myriad of potential drivers of weight gain accompanying complex global nutrition, economic, and technological transitions (97). -their relative causal contributions, however, cannot be inferred on that the population level. -nonetheless, evidence to suggest carbohydrate intake explains between-country differences in body weight is nonexistent and recent trends do not support that dietary carbohydrate is the main driver of the us obesity epidemic. -longitudinal cohort data have similarly identified several po- tential nutritional risk factors well beyond simple macronutrient composition for midlife weight gain. -for example, an analysis of 121,335 healthy us adults related individual-level changes in dietary fats compared with carbohydrates with concomitant changes in body weight over 20 y of follow-up (98). -participants increasing calories from total fat at the expense of carbohydrate had modestly less weight gain over time, supporting a potential role for carbohydrate reduction in mitigating increases in weight gain in middle age. -however, when the type of fat replacing the carbohydrate calories was considered, it was clear that changes in the quality of foods contributing dietary fat explained significant differences in weight gain above and beyond any contribution from a reduction in carbohydrate calories per se. -a reduction in carbohydrates with increases in animal source fats was associated with significantly greater weight gain, whereas the same reduction in carbohydrates with increases in polyunsaturated fats was correlated with significantly less weight gain. -a large body of epidemiological evidence consistently finds meaningful differences in risk of overweight and obesity according to long-term adherence to a variety of healthful dietary patterns (99) and foods (100, 101), all with highly variable carbohydrate contents. -for example, increasing intakes of potato chips, unprocessed red meat, and sugary beverages were significantly related to midlife weight gain, whereas increases in servings of whole grains, yogurt, and nuts related to weight loss (102). -thus, in addition to genetic factors, heterogeneity in weight gain is explained by variation in several nutritional factors and diet quality, independent of carbohydrate and glycemic index (103, 104). -these data, consistent with the ebm, suggest a variety of potential dietary drivers of excess calorie intake but do not support the cim proposition that dietary carbohydrates are the primary driver of obesity. -human diet intervention studies the cim predicts that meaningful long-term weight loss is readily achieved through a reduction in dietary carbohydrate and glycemic load because such interventions directly address the fundamental cause of obesity and should thereby facilitate its reversal. -indeed, the cim claims that patients may experience less hunger and improved energy level, promoting spontaneous weight loss and weight reduction produced by carbohydrate restriction would result in lower spontaneous food intake (5). -energy balance model of obesity 1249 however, diet intervention trials have found that low-glycemic- load diets do not generally result in significantly greater long- term weight loss as compared with higher-glycemic-load diets (105 112). -dietary protein can be a significant confounder in diet intervention studies and should be matched when evaluating the effects of glycemic load per se. -for example, a study examining maintenance of lost weight over a 6 mo period found that only a high-protein, low-glycemic-index diet prevented weight regain whereas significant weight regain was observed for a low-glycemic-index diet and higher-glycemic- lower-protein, index diets with high or low protein (113). -interestingly, longer studies investigating maintenance of lost weight failed to show a benefit of low- compared with high-glycemic-index diets (114, 115). -a meta-analysis of 53 randomized controlled trials of 1-y duration evaluated the effects of low-fat compared with higher-fat dietary interventions and found no significant difference in mean weight loss comparing the low-fat with higher-fat diets when dietary interventions were delivered with similar intensity (116). -an updated network meta-analyses of 121 randomized controlled trials found no significant difference in mean weight loss at 6 mo comparing low-fat, low-carbohydrate, or moderate-carbohydrate with usual diet controls (117). -for the individual diet types, jenny craig (55 60% carbohydrate) and atkins ( 10% carbohydrate) were the most effective at 6 mo; however, at 12 mo, mean weight loss was significantly greater for jenny craig compared with atkins. -the cim perspective admitted that most participants in these studies have difficulty sustaining dietary change (5), but this explanation is contrary to predictions of the cim because low-glycemic-load diets should promote diet adherence by spontaneously decreasing hunger in comparison with higher- glycemic-load alternatives. -in contrast, the ebm predicts that a variety of macronutrient compositions and eating patterns can result loss, so long as they ulti- mately confer a sustained reduction in energy intake. -the ebm is not constrained by the degree of effort necessary to sustain adherence across diet types, and readily accommodates a direct influence of internal signals and the complex and dynamic food environment on the long-term control of energy intake that make it difficult to sustain dietary adherence (118 120). -in long-term weight to avoid the confounder of diet adherence, inpatient feeding studies prevent access to off-study food. -under such conditions, exposure to a high-glycemic-load diet is predicted by the cim to lead to excess insulin secretion, accumulation of body fat, and downstream increases in appetite leading to greater ad libitum energy intake as compared with a lower-glycemic- load diet. -however, a recent month-long inpatient study found that a 2 wk exposure to a high-glycemic-load diet resulted in 700 kcal/d lower ad libitum energy intake and body fat loss compared with the 2 wk spent by the same participants on a very-low-glycemic-load diet (121). -additionally, these results occurred despite the low-glycemic-load diet resulting in substantially lower insulin secretion. -although this study provides important evidence directly contradicting the cim s predictions, it was wholly dismissed in the cim perspective as an example of the pitfalls of extrapolating chronic macronutrient effects from studies of a few weeks duration when the effects of the high-glycemic-load diet and excess postprandial insulin on appetite were apparently dominated by factors of dubious relation to chronic energy balance such as utensil size or plate color (5). -interestingly, a recent outpatient controlled feeding study found that 10 to 15 wk of a high-carbohydrate diet significantly increased satiety compared with a low-carbohydrate diet despite resulting in significantly higher postprandial insulin and lower circulating fuels (122), which again refutes the cim predictions and is consistent with the shorter inpatient study (121). -the cim predicts that lower-carbohydrate diets decrease insulin and thereby mobilize fat from adipose tissue to result in greater fat loss compared with isocaloric higher-carbohydrate diets with matched protein. -however, controlled feeding studies have produced results inconsistent with this prediction. -for example, selective carbohydrate restriction led to substantial decreases in daily insulin secretion in patients with obesity but resulted in slightly less body fat loss compared with isocaloric selective fat restriction in the same patients (58). -a meta- analysis of controlled feeding studies comparing isocaloric diets matched for protein found a small but significantly greater body fat loss with higher-carbohydrate diets (123). -furthermore, a recent 6-wk controlled feeding study found no significant differences in body fat loss between isocaloric very-low- carbohydrate compared with low-fat diets matched for protein (124). -finally, a 17-wk controlled feeding study employing isocaloric diets varying in glycemic load but matched for protein also failed to observe significant differences in body fat loss (109). -the ebm proposes that high dietary energy density is a potentially important driver of excess energy intake, and several trials have demonstrated significant long-term effects of diets differing in energy density (125 128). -however, these data were ignored in the cim perspective, and the possibility of energy density being potentially important in long-term control of energy intake was rejected (5) on the basis of a single exploratory finding of no significant long-term weight loss in patients with breast cancer who were advised to eat more fruits and vegetables (129). -furthermore, the cim perspective conflated the concept of food palatability with ultraprocessed food, and it was claimed that there is a lack of relevant human intervention studies on the topic (5). -but this ignored the results of a month-long inpatient human trial demonstrating excess ad libitum energy intake and weight gain when people were exposed to controlled food environments characterized by either ultraprocessed or unprocessed diets rated as similarly palatable and closely matched for available energy, macronutrients, sugar, sodium, fiber, and glycemic load (130). -such results demonstrate that factors other than dietary macronutrient composition and glycemic load can play important roles influencing human energy intake. -human pharmacological intervention studies pharmacological manipulations can also be used to interrogate the validity of obesity models. -an oft cited example in support of the cim is that exogenous insulin treatment in people with insulin therapy in diabetes often induces weight gain. -but treatment-na ve patients with type 1 diabetes normalizes their pathophysiological catabolic state and results in increased lean mass, reductions in atp-requiring metabolic futile cycles, nor- malization of adipose tissue lipolysis, elimination of glycosuria, 1250 hall et al. -and, contrary to the cim, resolution of polyphagia. -further, this all occurs despite insulin therapy decreasing circulating fuels. -in type 2 diabetes, weight gain with insulin therapy can be due, in part, to regain of recently lost weight (131 133). -acute peripheral infusions of insulin have mixed effects on appetite and food intake in humans (134, 135), but intranasal insulin delivery to the brain inhibits food intake (136), consistent with rodent studies (137) and contrary to the cim. -the cim posits that a major reason why insulin induces weight gain is due to its effect on inhibiting adipose tissue lipolysis thereby trapping fat in fat cells (5). -however, inhibiting adipose lipolysis with acipimox treatment for 6 mo had no significant effects on energy intake, resting energy expenditure, or body composition despite achieving a marked 38% reduction of plasma free fatty acid concentrations in adults with obesity (138). -finally, despite acutely increasing insulin secretion, glp-1 receptor agonists are currently the most effective approved medications to treat obesity (139). -conclusions the principle of energy balance is a necessary constraint on all potentially viable models of obesity, including the cim and ebm. -both models agree that diet quality and composition are important in prevention and treatment of obesity. -both models account for endocrine regulation, peripheral energy sensing, and energy partitioning. -the latest iteration of the cim retreats from its previous focus on postprandial insulin s direct effect on adipose tissue, but the new cim differs from the ebm in that high-glycemic-load diets are identified as the main driver of increasing obesity prevalence. -however, an overwhelming amount of evidence indicates that numerous variables in the food environment beyond high-glycemic foods can result in increased energy intake and the ebm posits that obesity can arise if any one or more of these factors are in play. -the ebm acknowledges the potential benefits of low- carbohydrate or low-glycemic-load diets in managing body weight or cardiometabolic outcomes in some individuals. -preci- sion nutrition initiatives have stemmed from a hypothesis of in- herent biological heterogeneity when an optimizing individuals diet (108, 140 142). -whereas such efforts are consistent with the multifactorial ebm, the cim sets forth a single exposure as the primary determinant of common obesity and proposes a single practical strategy to treat obesity by prescribing low-glycemic- load diets (5) despite evidence that such interventions are no more effective than prescribing higher-glycemic-load alternatives (105 112, 114, 115). -overall, we have documented a large body of evidence aligning with the ebm but inconsistent with the cim. -further development of the ebm requires elucidation of the factors in the dynamic food environment that are most responsible for instigating obesity, the mechanisms by which these factors alter the brain circuits controlling food intake, and why some individuals are more susceptible to development of obesity than others. -answering these questions will result in improved public health and medical interventions for prevention and treatment of obesity. -we thank stephan guyenet for helpful comments on an earlier draft of the manuscript. -the authors responsibilities were as follows kdh, jmf, sk, so r, jrs, er, dkt: wrote the first draft of the manuscript; kdh: takes responsibility for design, writing, and the final content; and all authors: participated in manuscript revision, and read and approved the final manuscript. -kdh has participated in several debates with david s. ludwig on the merits and demerits of the cim and has received funding from the nutrition science initiative to test predictions of the cim. -jf reports royalty payments for leptin for the treatment of lipodystrophy. -sk serves as a scientific consultant for altimmune, janssen, and b2m and has a sponsored research agreement with janssen. -so r receives remuneration for scientific advice from pfizer, astrazeneca and thirdrock ventures. -dhr reports personal fees from altimmune, personal fees from amgen, personal fees and non-financial support from boeringer ingelheim, personal fees and non-financial support from calibrate, personal fees and non-financial support from epitomee, personal fees from gila therapeutics, personal fees and non- financial support from ifa celtic, personal fees and non-financial support from janssen, personal fees and non-financial support from novo nordisk, personal fees from phenomix, personal fees from quintiles, personal fees and non-financial support from real appeal (united health care), personal fees from rhythm, personal fees and non-financial support from sanofi, personal fees and non-financial support from scientific intake, personal fees and non-financial support from xeno bioscience, personal fees from ysopia, personal fees from zealand, personal fees from lilly, personal fees from wondr health, personal fees from roman health, outside the submitted work. -all other authors report no conflicts of interest. -references 1. elks ce, den hoed m, zhao jh, sharp sj, wareham nj, loos rj, ong kk. -variability in the heritability of body mass index: a systematic review and meta-regression. -front endocrinol 2012;3:29. -2. stunkard aj, foch tt, hrubec z. a twin study of human obesity. -jama 1986;256(1):51 4. -3. church t, martin ck. -the obesity epidemic: a consequence of reduced 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-provision of foods differing in energy density affects long-term weight loss. -obes res 2005;13(6):1052 60. -129. saquib n, natarajan l, rock cl, flatt sw, madlensky l, kealey s, pierce jp. -the impact of a long-term reduction in dietary energy density on body weight within a randomized diet trial. -nutr cancer 2007;60(1):31 8. -130. hall kd, ayuketah a, brychta r, cai h, cassimatis t, chen ky, chung st, costa e, courville a, darcey v, et al. -ultra-processed diets cause excess calorie intake and weight gain: an inpatient randomized controlled trial of ad libitum food intake. -cell metab 2019;30(1):67 77.e3. -131. edens ma, van dijk pr, hak e, bilo hjg. -course of body weight before and after the initiation of insulin therapy in type 2 diabetes mellitus: retrospective inception cohort study (zodiac 58). -endocrinol diabetes metab 2021;4(2):e00212. -132. larger e, rufat p, dubois-laforgue d, ledoux s. insulin therapy does not itself induce weight gain in patients with type 2 diabetes. 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pennington aw. -obesity. -med times 1952;80(7):389 98. -145. pennington aw. -an alternate approach to the problem of obesity. -am j clin nutr 1953;1(2):100 6. -146. pennington aw. -a reorientation on obesity. -n engl j med 1953;248(23):959 64. -147. pennington aw. -obesity: overnutrition or disease of metabolism? -am j dig dis 1953;20(9):268 74. -148. pennington aw. -pathophysiology of obesity. -am j dig dis 1954;21(3):69 73. -1254 hall et al. -149. astwood eb. -the heritage of corpulence. -endocrinology 1962;71(2):337 41. -150. friedman mi. -body fat and the metabolic control of food intake. -int j obes 1990;14(suppl 3):53 66; discussion 66 7. -153. friedman mi, stricker em. -the physiological psychology of hunger: a physiological perspective. -psychol rev 1976;83(6): 409 31. -154. ludwig ds. -dietary glycemic index and obesity. -j nutr 151. friedman mi. -an energy sensor for control of energy intake. -proc nutr 2000;130(2):280s 3s. -soc 1997;56(1a):41 50. -152. friedman mi. -fuel partitioning and food intake. -am j clin nutr 1998;67(3):513s 18s. -155. lustig rh. -childhood obesity: behavioral aberration or biochemical drive? -reinterpreting the first law of thermodynamics. -nat clin pract endocrinol metab 2006;2(8):447 58. - -Book 4: - dietary reference intakes (dri) t he dietary reference intakes (dri) include two sets of values that serve as goals for nutrient intake recommended dietary allowances (rda) and adequate intakes (ai). -the rda re ect the average daily amount of a nutrient considered adequate to meet the needs of most healthy people. -if there is insuf cient evidence to determine an rda, an ai is set. -ai are more tentative than rda, but both may be used as goals for nutrient intakes. -(chapter 1 provides more details.) -in addition to the values that serve as goals for nutrient intakes (presented in the tables on these two pages), the dri include a set of values called tolerable upper intake levels (ul). -the ul represent the maximum amount of a nutrient that appears safe for most healthy people to consume on a regular basis. -turn the page for a listing of the ul for selected vitamins and minerals. -estimated energy requirements (eer), recommended dietary allowances (rda), and adequate intakes (ai) for water, energy, and the energy nutrients ht, ht, mi 2) reference b (kg/m reference heig cm (in) reference weig kg (lb) (l/day) a water ai energy eer b (kcal/day) hydrate (g/day) (g/day) ber total a d r ai o carb (g/day) total fat ai oleic acid (g/day) lin ai lin ai c olenic acid (g/day) d (g/day) protein a d r protein a d r (g/kg/day) 15.3 17.2 20.5 22.5 15.3 17.4 20.4 21.5 62 (24) 71 (28) 86 (34) 115 (45) 144 (57) 174 (68) 177 (70) 6 (13) 9 (20) 12 (27) 20 (44) 36 (79) 61 (134) 70 (154) 62 (24) 71 (28) 86 (34) 115 (45) 144 (57) 163 (64) 163 (64) 6 (13) 9 (20) 12 (27) 20 (44) 37 (81) 54 (119) 57 (126) age(yr) males 0 0.5 0.5 1 1 3g 4 8g 9 13 14 18 19 30 31 50 (cid:3)50 females 0 0.5 0.5 1 1 3g 4 8g 9 13 14 18 19 30 31 50 (cid:3)50 pregnancy 1st trimester 2nd trimester 3rd trimester lactation 1st 6 months 2nd 6 months 0.7e 0.8f 1.3 1.7 2.4 3.3 3.7 3.7 3.7 0.7e 0.8f 1.3 1.7 2.1 2.3 2.7 2.7 2.7 3.0 3.0 3.0 3.8 3.8 570 743 1046 1742 2279 3152h 3067h 3067h 3067h 520 676 992 1642 2071 2368 2403i 2403i 2403i (cid:4)0 (cid:4)340 (cid:4)452 (cid:4)330 (cid:4)400 60 95 130 130 130 130 130 130 130 60 95 130 130 130 130 130 130 130 175 175 175 210 210 19 25 31 38 38 38 30 19 25 26 26 25 25 21 28 28 28 29 29 31 30 31 30 4.4 4.6 7 10 12 16 17 17 14 4.4 4.6 7 10 10 11 12 12 11 13 13 13 13 13 0.5 0.5 0.7 0.9 1.2 1.6 1.6 1.6 1.6 0.5 0.5 0.7 0.9 1.0 1.1 1.1 1.1 1.1 1.4 1.4 1.4 1.3 1.3 9.1 11 13 19 34 52 56 56 56 9.1 11 13 19 34 46 46 46 46 (cid:4)25 (cid:4)25 (cid:4)25 (cid:4)25 (cid:4)25 1.52 1.2 1.05 0.95 0.95 0.85 0.8 0.8 0.8 1.52 1.2 1.05 0.95 0.95 0.85 0.8 0.8 0.8 1.1 1.1 1.1 1.3 1.3 note: for all nutrients, values for infants are ai. -dashes indicate that values have not been determined. -athe water ai includes drinking water, water in beverages, and water in foods; in general, drinking water and other beverages contribute about 70 to 80 percent, and foods, the remainder. -conversion factors: 1 l (cid:2) 33.8 uid oz; 1 l (cid:2) 1.06 qt; 1 cup (cid:2) 8 uid oz. -bthe estimated energy requirement (eer) represents the average dietary energy intake that will maintain energy balance in a healthy person of a given gender, age, weight, height, and physical activity level. -the values listed are based on an active person at the reference height and weight and at the midpoint ages for each group until age 19. chapter 8 and appendix f provide equa- tions and tables to determine estimated energy requirements. -cthe linolenic acid referred to in this table and text is the omega-3 fatty acid known as alpha- linolenic acid. -dthe values listed are based on reference body weights. -eassumed to be from human milk. -fassumed to be from human milk and complementary foods and beverages. -this includes approximately 0.6 l (~3 cups) as total uid including formula, juices, and drinking water. -gfor energy, the age groups for young children are 1 2 years and 3 8 years. -hfor males, subtract 10 kcalories per day for each year of age above 19. ifor females, subtract 7 kcalories per day for each year of age above 19. source: adapted from the dietary reference intakes series, national academies press. -copyright 1997, 1998, 2000, 2001, 2002, 2004, 2005 by the national academies of sciences. -a recommended dietary allowances (rda) and adequate intakes (ai) for vitamins g/day) g/day) avin (m (m niacin a a o d d rib r r hiamin t a pantothenic acid g/day) g/day) (cid:3)g/day) vitamin b 6 (m ai (m biotin a ai ( d r g/day) (m folate a d r b c g/day) g/day) g/day) vitamin b 12 vitamin c oline (m ai ( a d r g/day) vitamin a (m a d r h c ( a d r d g/day) g/day) vitamin d vitamin e ai ( g/day) g/day) vitamin k (m ai ( a d r ( a d r e 0.2 0.3 0.5 0.6 0.9 1.2 1.2 1.2 1.2 1.2 0.9 1.0 1.1 1.1 1.1 1.1 1.4 1.4 1.4 1.4 1.4 1.4 0.3 0.4 0.5 0.6 0.9 1.3 1.3 1.3 1.3 1.3 0.9 1.0 1.1 1.1 1.1 1.1 1.4 1.4 1.4 1.6 1.6 1.6 2 4 6 8 12 16 16 16 16 16 12 14 14 14 14 14 18 18 18 17 17 17 5 6 8 12 20 25 30 30 30 30 20 25 30 30 30 30 30 30 30 35 35 35 1.7 1.8 2 3 4 5 5 5 5 5 4 5 5 5 5 5 6 6 6 7 7 7 0.1 0.3 0.5 0.6 1.0 1.3 1.3 1.3 1.7 1.7 1.0 1.2 1.3 1.3 1.5 1.5 1.9 1.9 1.9 2.0 2.0 2.0 65 80 150 200 300 400 400 400 400 400 300 400 400 400 400 400 600 600 600 500 500 500 0.4 0.5 0.9 1.2 1.8 2.4 2.4 2.4 2.4 2.4 1.8 2.4 2.4 2.4 2.4 2.4 2.6 2.6 2.6 2.8 2.8 2.8 125 150 200 250 375 550 550 550 550 550 375 400 425 425 425 425 450 450 450 550 550 550 40 50 15 25 45 75 90 90 90 90 45 65 75 75 75 75 80 85 85 400 500 300 400 600 900 900 900 900 900 600 700 700 700 700 700 750 770 770 115 120 120 1200 1300 1300 5 5 5 5 5 5 5 5 10 15 5 5 5 5 10 15 5 5 5 5 5 5 4 5 6 7 11 15 15 15 15 15 11 15 15 15 15 15 15 15 15 19 19 19 2.0 2.5 30 55 60 75 120 120 120 120 60 75 90 90 90 90 75 90 90 75 90 90 age (yr) infants 0 0.5 0.5 1 children 1 3 4 8 males 9 13 14 18 19 30 31 50 51 70 (cid:4)70 females 9 13 14 18 19 30 31 50 51 70 (cid:4)70 pregnancy 18 19 30 31 50 lactation 18 19 30 31 50 note: for all nutrients, values for infants are ai. -the glossary on the inside back cover de nes units of nutrient measure. -aniacin recommendations are expressed as niacin equivalents (ne), except for recommendations for infants younger than 6 months, which are expressed as preformed niacin. -bfolate recommendations are expressed as dietary folate equivalents (dfe). -cvitamin a recommendations are expressed as retinol activity equivalents (rae). -dvitamin d recommendations are expressed as cholecalciferol and assume an absence of adequate exposure to sunlight. -evitamin e recommendations are expressed as (cid:2)-tocopherol. -recommended dietary allowances (rda) and adequate intakes (ai) for minerals g/day) hloride m (m diu ai so g/day) otassiu (m ai g/day) m calciu (m ai p c g/day) g/day) orus nesiu (m h osp (m a mag d h ai r p g/day) m (m a d r n iro m g/day) (m a zinc d r g/day) (m dine a d io r g/day) seleniu m ( a d r g/day) ( per a p d o r c g/day) ganese man g/day) g/day) m miu oride (m (m ( hro flu ai ai ai c m g/day) u den ( olyb a d m r ( a d r g/day) 120 370 1000 1200 1500 1500 1500 1500 1300 1200 1500 1500 1500 1500 1300 1200 1500 1500 1500 1500 1500 1500 180 570 1500 1900 2300 2300 2300 2300 2000 1800 2300 2300 2300 2300 2000 1800 2300 2300 2300 2300 2300 2300 400 700 3000 3800 4500 4700 4700 4700 4700 4700 4500 4700 4700 4700 4700 4700 4700 4700 4700 5100 5100 5100 210 270 500 800 1300 1300 1000 1000 1200 1200 1300 1300 1000 1000 1200 1200 1300 1000 1000 1300 1000 1000 100 275 460 500 1250 1250 700 700 700 700 1250 1250 700 700 700 700 1250 700 700 1250 700 700 30 75 80 130 240 410 400 420 420 420 240 360 310 320 320 320 400 350 360 360 310 320 0.27 11 7 10 8 11 8 8 8 8 8 15 18 18 8 8 27 27 27 10 9 9 2 3 3 5 8 11 11 11 11 11 8 9 8 8 8 8 12 11 11 13 12 12 110 130 90 90 120 150 150 150 150 150 120 150 150 150 150 150 220 220 220 290 290 290 15 20 20 30 40 55 55 55 55 55 40 55 55 55 55 55 60 60 60 70 70 70 200 220 340 440 700 890 900 900 900 900 700 890 900 900 900 900 1000 1000 1000 1300 1300 1300 0.003 0.6 0.01 0.5 0.2 5.5 1.2 1.5 1.9 2.2 2.3 2.3 2.3 2.3 1.6 1.6 1.8 1.8 1.8 1.8 2.0 2.0 2.0 2.6 2.6 2.6 0.7 1.0 2 3 4 4 4 4 2 3 3 3 3 3 3 3 3 3 3 3 11 15 25 35 35 35 30 30 21 24 25 25 20 20 29 30 30 44 45 45 2 3 17 22 34 43 45 45 45 45 34 43 45 45 45 45 50 50 50 50 50 50 b age (yr) infants 0 0.5 0.5 1 children 1 3 4 8 males 9 13 14 18 19 30 31 50 51 70 (cid:4)70 females 9 13 14 18 19 30 31 50 51 70 (cid:4)70 pregnancy 18 19 30 31 50 lactation a 18 19 30 31 50 tolerable upper intake levels (ul) for vitamins a vitamin b 6 g/day) g/day) folate (m (m niacin ( a g/day) b g/day) g/day) vitamin a vitamin c g/day) oline (m (m ( h c vitamin d g/day) ( c g/day) vitamin e (m 10 15 20 30 35 35 30 35 30 35 30 40 60 80 100 100 80 100 80 100 300 400 600 1000 1000 2000 400 650 1200 600 600 600 900 1700 800 3000 1800 2800 1000 1000 800 1000 800 1000 3500 3500 3000 3500 3000 3500 2000 2000 1800 2000 1800 2000 3000 3000 2800 3000 2800 3000 25 25 50 50 50 50 50 50 50 50 50 50 200 300 600 800 1000 1000 800 1000 800 1000 age (yr) infants 0 0.5 0.5 1 children 1 3 4 8 9 13 adolescents 14 18 adults 19 70 (cid:3)70 pregnancy 18 19 50 lactation 18 19 50 athe ul for niacin and folate apply to synthetic forms obtained from supplements, forti ed foods, or a combination of the two. -bthe ul for vitamin a applies to the preformed vitamin only. -cthe ul for vitamin e applies to any form of supplemental (cid:2)-tocopherol, forti ed foods, or a combination of the two. -tolerable upper intake levels (ul) for minerals g/day) m diu (m so hloride g/day) g/day) m calciu (m (m c orus g/day) h osp (m h p m d g/day) nesiu mag n (m iro g/day) zinc (m g/day) (m g/day) m g/day) seleniu ( dine ( io g/day) per p o ( c ganese g/day) g/day) oride man (m (m flu m u den g/day) olyb ( m g/day) n oro (m b m g/day) vanadiu nickel (m g/day) (m e e 1500 1900 2200 e e 2300 2900 3400 2500 2500 2500 3000 3000 4000 65 110 350 2300 3600 2500 4000 350 2300 2300 2300 2300 2300 2300 3600 3600 3600 3600 3600 3600 2500 2500 2500 2500 2500 2500 4000 3000 3500 3500 4000 4000 350 350 350 350 350 350 40 40 40 40 40 45 45 45 45 45 45 45 4 5 7 12 23 34 40 40 34 40 34 40 200 300 600 45 60 90 150 280 1000 3000 5000 900 400 8000 1100 1100 900 1100 900 1100 400 400 400 400 400 400 10,000 10,000 8000 10,000 8000 10,000 2 3 6 9 11 11 9 11 9 11 0.7 0.9 1.3 2.2 10 10 10 10 10 10 10 10 300 600 1100 1700 2000 2000 1700 2000 1700 2000 3 6 11 17 20 20 17 20 17 20 0.2 0.3 0.6 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.8 1.8 age (yr) infants 0 0.5 0.5 1 children 1 3 4 8 9 13 adolescents 14 18 adults 19 70 (cid:3)70 pregnancy 18 19 50 lactation 18 19 50 dthe ul for magnesium applies to synthetic forms obtained from supplements or drugs only. -esource of intake should be from human milk (or formula) and food only. -note: an upper limit was not established for vitamins and minerals not listed and for those age groups listed with a dash ( ) because of a lack of data, not because these nutrients are safe to consume at any level of intake. -all nutrients can have adverse effects when intakes are excessive. -source: adapted with permission from the dietary reference intakes series, national academy press. -copyright 1997, 1998, 2000, 2001, 2002, 2005 by the national academy of sciences. -courtesy of the national academy press, washington, d.c. c u n d e r s ta n d i n g nutrition this page intentionally left blank e l e v e n t h e d i t i o n ellie whitney sharon rady rolfes australia canada mexico singapore spain united kingdom united states understanding nutrition, eleventh edition ellie whitney, sharon rady rolfes permissions editor: sarah d stair production service: the book company, dusty friedman text designer: diane beasley photo researcher: roman barnes, paul forkner copy editor: mary douglas illustrator: imagineering, lachina publishing services cover designer: dare porter cover image: masterfile corporation cover printer: r.r. -donnelley/willard compositor: lachina publishing services printer: r.r. -donnelley/willard thomson higher education 10 davis drive belmont, ca 94002-3098 usa executive editor: peter adams development editor: nedah rose assistant editor: elesha feldman, kate franco editorial assistant: jean blomo technology project manager: ericka yeoman-saler marketing manager: jennifer somerville marketing assistant: catie ronquillo marketing communications manager: jessica perry project manager, editorial production: cheryll linthicum creative director: rob hugel art director: john walker print buyer: becky cross 2008, 2005 thomson wadsworth, a part of the thomson corporation. -thomson, the star logo, and wadsworth are trademarks used herein under license. -all rights reserved. -no part of this work covered by the copyright hereon may be reproduced or used in any form or by any means graphic, electronic, or mechanical, including pho- tocopying, recording, taping, web distribution, information storage and retrieval systems, or in any other manner without the written permission of the publisher. -printed in the united states of america 1 2 3 4 5 6 7 11 10 09 08 07 for more information about our products, contact us at: thomson learning academic resource center 1-800-423-0563 for permission to use material from this text or product, submit a request online at: http://www.thomsonrights.com any additional questions about permissions can be submitted by email to thomsonrights@thomson.com. -examview and examview pro are registered trademarks of fscreations, inc. windows is a registered trademark of the microsoft corporation used herein under license. -macintosh and power macintosh are registered trademarks of apple computer, inc. used herein under license. -2008 thomson learning, inc. all rights reserved. -thomson learning webtutor is a trademark of thomson learning, inc. library of congress control number: 2007920597 student edition: isbn-13: 978-0-495-11669-1 isbn-10: 0-495-11669-6 to the memory of gary woodruff, the editor who first encouraged me to write. -ellie to ellie whitney, my mentor, partner, and friend, with much appreciation for believing in me, sharing your wisdom, and giving me the opportunity to pursue a career more challenging and rewarding than any i could have imagined. -sharon about the authors ellie whitney grew up in new york city and received her b.a. -and ph.d. degrees in english and biology at radcliffe/harvard university and washington university, respectively. -she has lived in tallahassee since 1970, has taught at both florida state university and florida a&m university, has written newspaper columns on environmental matters for the tallahassee democrat, and has authored almost a dozen college textbooks on nutrition, health, and related top- ics, many of which have been revised multiple times over the years. -in addition to teaching and writing, she has spent the past three-plus decades exploring out- door florida and studying its ecology. -her latest book is priceless florida: the nat- ural ecosystems (pineapple press, 2004). -sharon rady rolfes received her m.s. -in nutrition and food science from florida state university. -she is a founding member of nutrition and health asso- ciates, an information resource center that maintains a research database on over 1000 nutrition-related topics. -her other publications include the college textbooks understanding normal and clinical nutrition and nutrition for health and health care and a multimedia cd-rom called nutrition interactive. -in addition to writing, she occasionally teaches at florida state university and serves as a consult- ant for various educational projects. -her volunteer work includes coordinating meals for the hungry and homeless and serving on the steering committee of work- ing well leon county, a community initiative designed to help local businesses im- prove the health and well-being of their employees. -she maintains her registration as a dietitian and membership in the american dietetic association. -brief contents chapter 1 chapter 2 chapter 3 chapter 4 chapter 5 chapter 6 an overview of nutrition h i g h l i g h t nutrition information and misinformation on the net and in the news 30 2 36 planning a healthy diet h i g h l i g h t vegetarian diets 64 digestion, absorption, and transport h i g h l i g h t common digestive problems 92 70 the carbohydrates: sugars, starches, and fibers h i g h l i g h t alternatives to sugar 132 100 the lipids: triglycerides, phospholipids, and sterols 138 h i g h l i g h t high-fat foods friend or foe? -172 protein: amino acids h i g h l i g h t nutritional genomics 207 180 chapter 7 metabolism: transformations and interactions 212 h i g h l i g h t alcohol and nutrition 238 chapter 8 energy balance and body composition 248 h i g h l i g h t eating disorders 270 chapter 9 weight management: overweight, obesity, and underweight 280 h i g h l i g h t the latest and greatest weight-loss diet again 315 chapter 10 the water-soluble vitamins: b vitamins and vitamin c 322 h i g h l i g h t vitamin and mineral supplements 360 chapter 11 the fat-soluble vitamins: a, d, e, and k 368 h i g h l i g h t antioxidant nutrients in disease prevention 390 chapter 12 water and the major minerals 396 h i g h l i g h t osteoporosis and calcium 431 viii brief contents chapter 13 the trace minerals 440 h i g h l i g h t phytochemicals and functional foods 469 chapter 14 fitness: physical activity, nutrients, and body adaptations 476 h i g h l i g h t supplements as ergogenic aids 503 chapter 15 life cycle nutrition: pregnancy and lactation 508 h i g h l i g h t fetal alcohol syndrome 543 chapter 16 life cycle nutrition: infancy, childhood, and adolescence 546 h i g h l i g h t childhood obesity and the early development of chronic diseases 586 chapter 17 life cycle nutrition: adulthood and the later years 592 h i g h l i g h t nutrient-drug interactions 615 chapter 18 diet and health 620 h i g h l i g h t complementary and alternative medicine 652 chapter 19 consumer concerns about foods and water 662 h i g h l i g h t food biotechnology 693 chapter 20 hunger and the global environment 700 h i g h l i g h t progress toward sustainable food production 716 a p p e n d i x a cells, hormones, and nerves a-2 a p p e n d i x b basic chemistry concepts b-1 a p p e n d i x c biochemical structures and pathways c-1 a p p e n d i x d measures of protein quality d-1 a p p e n d i x e nutrition assessment e-1 a p p e n d i x f physical activity and energy requirements f-1 a p p e n d i x g united states: exchange lists g-1 a p p e n d i x h table of food composition h-1 a p p e n d i x i who: nutrition recommendations canada: guidelines and meal planning i-1 a p p e n d i x j j-1 healthy people 2010 glossary gl-1 index in-1 aids to calculations w dietary reference intakes (inside front covers) daily values for food labels (inside back cover, left) glossary of nutrient measures (inside back cover, left) body mass index (bmi) (inside back cover, right) contents chapter 1 an overview of nutrition 3 food choices 2 the nutrients 5 nutrients in foods and in the body 6 the energy-yielding nutrients: carbohydrate, fat, and protein 7 the vitamins 10 the minerals 10 water 11 the science of nutrition conducting research 11 11 analyzing research findings 14 publishing research 15 dietary reference intakes 16 establishing nutrient recommendations 16 establishing energy recommendations 18 using nutrient recommendations 18 comparing nutrient recommendations 19 nutrition assessment 20 nutrition assessment of individuals 20 nutrition assessment of populations 22 diet and health 24 chronic diseases 24 risk factors for chronic diseases 24 h i g h l i g h t nutrition information and misinformation on the net and in the news 30 chapter 2 planning a healthy diet principles and guidelines 37 36 diet-planning principles 37 dietary guidelines for americans 39 diet-planning guides 41 usda food guide 41 exchange lists 47 putting the plan into action 48 from guidelines to groceries 48 food labels 54 the ingredient list 55 serving sizes 55 nutrition facts 55 the daily values 56 nutrient claims 58 health claims 59 structure-function claims 59 consumer education 60 h i g h l i g h t vegetarian diets 64 chapter 3 digestion, absorption, and transport digestion 70 71 anatomy of the digestive tract 72 the muscular action of digestion 74 the secretions of digestion 76 the final stage 78 absorption 80 anatomy of the absorptive system 80 a closer look at the intestinal cells 81 the circulatory systems the vascular system 83 83 the lymphatic system 84 the health and regulation of the gi tract 86 gastrointestinal bacteria 86 gastrointestinal hormones and nerve pathways 86 the system at its best 88 h i g h l i g h t common digestive problems 92 chapter 4 the carbohydrates: sugars, starches, and fibers the chemist s view of carbohydrates 100 101 the simple carbohydrates 102 x contents monosaccharides 102 disaccharides 103 recommended intakes of fat from guidelines to groceries 160 161 the complex carbohydrates 105 h i g h l i g h t high-fat foods friend or foe? -172 glycogen 105 starches 105 fibers 106 digestion and absorption of carbohydrates 107 carbohydrate digestion 108 carbohydrate absorption 108 lactose intolerance 110 glucose in the body 111 a preview of carbohydrate metabolism 112 the constancy of blood glucose 113 health effects and recommended intakes of sugars 117 health effects of sugars 117 controversies surrounding sugars 119 recommended intakes of sugars 121 chapter 6 protein: amino acids the chemist s view of proteins 180 181 amino acids 181 proteins 183 digestion and absorption of protein 185 protein digestion 185 protein absorption 185 proteins in the body 187 protein synthesis 187 roles of proteins 189 a preview of protein metabolism 193 health effects and recommended intakes of starch and fibers 122 protein in foods 195 protein quality 195 health effects of starch and fibers 122 recommended intakes of starch and fibers 124 from guidelines to groceries 125 h i g h l i g h t alternatives to sugar 132 chapter 5 the lipids: triglycerides, phospholipids, and sterols the chemist s view of fatty acids and triglycerides 139 138 fatty acids 140 triglycerides 142 degree of unsaturation revisited 142 the chemist s view of phospholipids and sterols 145 phospholipids 145 sterols 146 digestion, absorption, and transport of lipids 147 lipid digestion 147 lipid absorption 149 lipid transport 150 lipids in the body 153 roles of triglycerides 153 essential fatty acids 154 a preview of lipid metabolism 155 health effects and recommended intakes of lipids 156 health effects of lipids 156 protein regulations for food labels 196 health effects and recommended intakes of protein 196 protein-energy malnutrition 196 health effects of protein 199 recommended intakes of protein 201 protein and amino acid supplements 202 h i g h l i g h t nutritional genomics 207 chapter 7 metabolism: transformations 212 and interactions chemical reactions in the body 214 breaking down nutrients for energy 217 glucose 219 glycerol and fatty acids 222 amino acids 224 breaking down nutrients for energy in summary 226 the final steps of catabolism 227 energy balance 230 feasting excess energy 232 the transition from feasting to fasting 233 fasting inadequate energy 233 h i g h l i g h t alcohol and nutrition 238 chapter 8 energy balance and body composition energy balance 248 249 energy in: the kcalories foods provide 250 food composition 250 food intake 251 energy out: the kcalories the body expends 253 components of energy expenditure 254 estimating energy requirements 256 body weight, body composition, and health 258 defining healthy body weight 258 body fat and its distribution 260 health risks associated with body weight and body fat 263 h i g h l i g h t eating disorders 270 chapter 9 weight management: overweight, obesity, and underweight overweight and obesity 280 281 fat cell development 282 fat cell metabolism 282 set-point theory 283 causes of overweight and obesity 283 genetics 284 environment 286 problems of overweight and obesity 288 health risks 288 perceptions and prejudices 289 dangerous interventions 289 aggressive treatments for obesity 292 drugs 292 surgery 292 weight-loss strategies eating plans 295 294 physical activity 299 environmental influences 302 behavior and attitude 303 weight maintenance 305 prevention 306 public health programs 306 contents xi underweight 307 problems of underweight 307 weight-gain strategies 307 h i g h l i g h t the latest and greatest weight-loss diet again 315 chapter 10 the water soluble vitamins: b vitamins and vitamin c 322 the vitamins an overview 323 the b vitamins as individuals 326 thiamin 327 riboflavin 328 niacin 331 biotin 333 pantothenic acid 335 vitamin b6 336 folate 338 vitamin b12 342 non-b vitamins 345 the b vitamins in concert 346 b vitamin roles 347 b vitamin deficiencies 348 b vitamin toxicities 349 b vitamin food sources 349 vitamin c 350 vitamin c roles 351 vitamin c recommendations 352 vitamin c deficiency 353 vitamin c toxicity 353 vitamin c food sources 354 h i g h l i g h t vitamin and mineral supplements 360 chapter 11 the fat soluble vitamins: a, d, e, and k 368 vitamin a and beta-carotene 369 roles in the body 370 vitamin a deficiency 372 vitamin a toxicity 374 vitamin a recommendations 374 vitamin a in foods 374 xii contents vitamin d 377 roles in the body 377 vitamin d deficiency 378 vitamin d toxicity 379 vitamin d recommendations and sources 379 vitamin e 381 vitamin e as an antioxidant 382 vitamin e deficiency 382 vitamin e toxicity 382 vitamin e recommendations 382 vitamin e in foods 383 vitamin k 383 roles in the body 384 vitamin k deficiency 384 vitamin k toxicity 385 vitamin k recommendations and sources 385 the fat-soluble vitamins in summary 385 h i g h l i g h t antioxidant nutrients in disease prevention 390 chapter 12 water and the major minerals water and the body fluids 397 water balance and recommended intakes 398 396 blood volume and blood pressure 401 fluid and electrolyte balance 402 fluid and electrolyte imbalance 406 acid-base balance 406 the minerals an overview 408 sodium 410 chloride 413 potassium 414 calcium 416 calcium roles in the body 416 calcium recommendations and sources 418 calcium deficiency 421 phosphorus 422 magnesium 423 sulfate 425 h i g h l i g h t osteoporosis and calcium 431 chapter 13 the trace minerals the trace minerals an overview 441 440 iron 442 iron roles in the body 442 iron absorption and metabolism 443 iron deficiency 445 iron toxicity 447 iron recommendations and sources 449 iron contamination and supplementation 450 zinc 452 zinc roles in the body 452 zinc absorption and metabolism 452 zinc deficiency 453 zinc toxicity 454 zinc recommendations and sources 454 zinc supplementation 455 iodine 455 selenium 457 copper 458 manganese 459 fluoride 460 chromium 461 molybdenum 462 other trace minerals 462 contaminant minerals 463 closing thoughts on the nutrients 463 h i g h l i g h t phytochemicals and functional foods 469 chapter 14 fitness: physical activity, nutrients, and body adaptations fitness 476 477 benefits of fitness 478 developing fitness 480 cardiorespiratory endurance 482 weight training 484 energy systems, fuels, and nutrients to support activity 484 chapter 16 contents xiii the energy systems of physical activity atp and cp 484 glucose use during physical activity 485 fat use during physical activity 488 protein use during physical activity and between times 490 vitamins and minerals to support activity 491 fluids and electrolytes to support activity 493 poor beverage choices: caffeine and alcohol 496 diets for physically active people 496 choosing a diet to support fitness 496 meals before and after competition 497 h i g h l i g h t supplements as ergogenic aids 503 chapter 15 life cycle nutrition: pregnancy 508 and lactation nutrition prior to pregnancy 509 growth and development during pregnancy 510 placental development 510 fetal growth and development 510 critical periods 512 maternal weight 515 weight prior to conception 516 weight gain during pregnancy 516 exercise during pregnancy 518 nutrition during pregnancy 519 energy and nutrient needs during pregnancy 520 vegetarian diets during pregnancy and lactation 524 common nutrition-related concerns of pregnancy 524 high-risk pregnancies 525 the infant s birthweight 525 malnutrition and pregnancy 526 food assistance programs 527 maternal health 527 the mother s age 529 practices incompatible with pregnancy 530 nutrition during lactation 532 lactation: a physiological process 533 breastfeeding: a learned behavior 534 life cycle nutrition: infancy, childhood, and adolescence nutrition during infancy 546 547 547 energy and nutrient needs breast milk 550 infant formula 552 special needs of preterm infants 554 introducing cow s milk 554 introducing solid foods 555 mealtimes with toddlers 557 nutrition during childhood 558 energy and nutrient needs 558 hunger and malnutrition in children 562 the malnutrition-lead connection 564 hyperactivity and hyper behavior 564 food allergy and intolerance 565 childhood obesity 567 mealtimes at home 571 nutrition at school 573 nutrition during adolescence growth and development 575 575 energy and nutrient needs 576 food choices and health habits 577 problems adolescents face 578 h i g h l i g h t childhood obesity and the early development of chronic diseases 586 chapter 17 life cycle nutrition: adulthood and the later years nutrition and longevity 592 594 observation of older adults 595 manipulation of diet 596 the aging process 597 physiological changes 598 other changes 600 energy and nutrient needs of older adults 601 maternal energy and nutrient needs during lactation 534 maternal health 536 practices incompatible with lactation 537 h i g h l i g h t fetal alcohol syndrome 543 water 601 energy and energy nutrients 601 vitamins and minerals 602 nutrient supplements 603 xiv contents nutrition-related concerns of older adults 604 vision 604 arthritis 605 the aging brain 606 food choices and eating habits of older adults 607 food assistance programs 608 meals for singles 609 h i g h l i g h t nutrient-drug interactions 615 chapter 18 620 diet and health nutrition and infectious diseases 621 the immune system 622 nutrition and immunity 623 hiv and aids 623 nutrition and chronic diseases 624 cardiovascular disease 626 how atherosclerosis develops 626 risk factors for coronary heart disease 628 recommendations for reducing coronary heart disease risk 630 hypertension 632 how hypertension develops 632 risk factors for hypertension 634 treatment of hypertension 635 diabetes mellitus 637 how diabetes develops 637 complications of diabetes 639 recommendations for diabetes 640 cancer 642 how cancer develops 642 recommendations for reducing cancer risk 645 recommendations for chronic diseases 646 h i g h l i g h t complementary and alternative medicine 652 chapter 19 consumer concerns about foods and water foodborne illnesses 662 664 foodborne infections and food intoxications 664 food safety in the marketplace 666 food safety in the kitchen 667 food safety while traveling 672 advances in food safety 672 nutritional adequacy of foods and diets 673 obtaining nutrient information 673 minimizing nutrient losses 674 environmental contaminants 674 harmfulness of environmental contaminants 674 guidelines for consumers 676 natural toxicants in foods 677 pesticides 678 hazards and regulation of pesticides 678 monitoring pesticides 679 consumer concerns 679 food additives 682 regulations governing additives 682 intentional food additives 683 indirect food additives 685 consumer concerns about water sources of drinking water 688 687 water systems and regulations 688 h i g h l i g h t food biotechnology 693 chapter 20 hunger and the global 700 environment hunger in the united states 702 defining hunger in the united states 702 relieving hunger in the united states 703 world hunger 705 food shortages 705 malnutrition 706 diminishing food supply 707 poverty and overpopulation 707 environmental degradation and hunger 709 environmental limitations in food production 709 other limitations in food production 710 solutions 710 sustainable development worldwide 711 activism and simpler lifestyles at home 711 h i g h l i g h t progress toward sustainable food production 716 contents xv a p p e n d i x a cells, hormones, and nerves a-2 a p p e n d i x b basic chemistry concepts b-1 a p p e n d i x c biochemical structures and pathways c-1 a p p e n d i x d measures of protein quality d-1 a p p e n d i x e nutrition assessment e-1 a p p e n d i x f physical activity and energy requirements f-1 a p p e n d i x g united states: exchange lists g-1 a p p e n d i x h table of food composition h-1 a p p e n d i x i who: nutrition recommendations canada: guidelines and meal planning i-1 a p p e n d i x j healthy people 2010 j-1 glossary gl-1 index in-1 aids to calculations w dietary reference intakes (inside front covers) daily values for food labels (inside back cover, left) glossary of nutrient measures (inside back cover, left) body mass index (bmi) (inside back cover, right) preface nutrition is a science. -the details of a nutrient s chemistry or a cell s biology can be overwhelming and confusing to some, but it needn t be. -when the science is explained step by step and the facts are connected one by one, the details become clear and understandable. -by telling stories about fat mice, using analogies of lamps, and applying guidelines to groceries, we make the science of nutrition meaningful and memorable. -that has been our goal since the first edition: to re- veal the fascination of science and share the excitement of nutrition with readers. -we have learned from the hundreds of professors and more than a million students who have used this book through the years that readers want to understand nutri- tion so that they can make healthy choices in their daily lives. -because nutrition is an active science, staying current is paramount. -to that end, this edition builds on the science of previous editions with the latest in nutri- tion research. -much has changed in the world of nutrition and in our daily lives since the first edition. -the number of foods has increased dramatically even as we spend less time than ever in the kitchen preparing meals. -the connections between diet and disease have become more apparent and our interest in making smart health choices has followed. -more people are living longer and healthier lives. -the science of nutrition has grown rapidly, with new facts emerging daily. -in this edi- tion, as with previous editions, every chapter has been substantially revised to re- flect the many changes that have occurred in the field of nutrition and in our daily lives over the years. -we hope that this book serves you well. -the chapters understanding nutrition presents the core information of an introduc- tory nutrition course. -the early chapters introduce the nutrients and their work in the body, and the later chapters apply that information to people s lives describing the role of foods and nutrients in energy balance and weight control, in physical activity, in the life cycle, in disease prevention, in food safety, and in hunger. -chapter 1 begins by exploring why we eat the foods we do and continues with a brief overview of the nutrients, the science of nutrition, recommended nutrient intakes, assessment, and important relationships between diet and health. -chapter 2 describes the diet-plan- ning principles and food guides used to create diets that support good health and in- cludes instructions on how to read a food label. -in chapter 3, readers follow the journey of digestion and absorption as the body transforms foods into nutrients. -chapters 4 through 6 describe carbohydrates, fats, and proteins their chemistry, roles in the body, and places in the diet. -then chapter 7 shows how the body derives energy from these three nutrients. -chapters 8 and 9 continue the story with a look at energy balance, the factors associated with overweight and underweight, and the benefits and dangers of weight loss and weight gain. -chapters 10 through 13 com- plete the introductory lessons by describing the vitamins, the minerals, and water their roles in the body, deficiency and toxicity symptoms, and sources. -the next seven chapters weave that basic information into practical applica- tions, showing how nutrition influences people s lives. -chapter 14 describes how physical activity and nutrition work together to support fitness. -chapters 15, 16, and 17 present the special nutrient needs of people through the life cycle preg- nancy and lactation; infancy, childhood, and adolescence; and adulthood and the later years. -chapter 18 focuses on the dietary risk factors and recommendations as- sociated with chronic diseases, and chapter 19 addresses consumer concerns about the safety of the food and water supply. -chapter 20 closes the book by examining preface xvii definition (def-eh-nish-en): the meaning of a word. -de = from finis = boundary hunger and the global environment and by exploring possible solutions for estab- lishing sustainable foodways. -the highlights every chapter is followed by a highlight that provides readers with an in-depth look at a current, and often controversial, topic that relates to its compan- ion chapter. -this edition features a new highlight on nutritional genomics the new field of study that explores how nutrients influence gene activity and how genes influ- ence the activities of nutrients. -special features the art and layout in this edition have been carefully designed to be inviting while enhancing student learning. -in addition, special features help readers identify key concepts and apply nutrition knowledge. -for example, when a new term is introduced, it is printed in bold type and a definition is provided. -these definitions often include pronunciations and derivations to facilitate under- standing. -the glossary at the end of the text includes all defined terms. -nutrition in your life each chapter begins with nutrition in your life sections that introduce the essence of the chapter in a friendly and familiar scenario. -nutrition portfolio at the end of the chapter, nutrition portfolio sections revisit that message and prompt readers to consider whether their personal choices are meeting the dietary goals intro- duced in the chapter. -in summary each major section within a chapter concludes with a summary paragraph that reviews the key concepts. -similarly, summary tables cue readers to impor- tant reviews. -also featured in this edition are the dietary guidelines for americans, 2005 recom- mendations, which are introduced in chapter 2 and presented throughout the text whenever their subjects are discussed. -look for the following design. -dietary guidelines for americans 2005 these guidelines provide science-based advice to promote health and to reduce the risk of chronic disease through diet and physical activity. -how to many of the chapters include how to sections that guide readers through problem-solving tasks. -for example, the how to in chapter 1 takes students through the steps of calculating energy intake from the grams of carbohydrate, fat, and protein in a food; another how to in chapter 20 describes how to plan healthy meals on a tight budget. -xviii preface nutrition calculations several chapters close with a nutrition calculation sec- tion. -these sections often reinforce the how to lessons and provide practice in doing nutrition-related calculations. -the problems enable readers to apply their skills to hypothetical situations and then check their answers (found at the end of the chapter). -readers who successfully master these exercises will be well prepared for real-life nutrition-related problems. -nutrition on the net each chapter and many highlights conclude with nutrition on the net a list of websites for further study of topics covered in the accompanying text. -these lists do not imply an endorse- ment of the organizations or their programs. -we have tried to provide reputable sources, but cannot be responsible for the content of these sites. -(read highlight 1 to learn how to find re- liable information on the internet.) -study questions each chapter ends with study questions in essay and multi- ple- choice format. -study questions offer readers the opportunity to review the major concepts presented in the chapters in prepa- ration for exams. -the page numbers after each essay question refer readers to discussions that answer the question; answers to the multiple-choice questions appear at the end of the chapter. -the appendixes the appendixes are valuable references for a number of purposes. -appendix a summarizes background information on the hormonal and nervous sys- tems, complementing appendixes b and c on basic chemistry, the chemical struc- tures of nutrients, and major metabolic pathways. -appendix d describes measures of protein quality. -appendix e provides detailed coverage of nutrition assessment, and appendix f presents the estimated energy requirements for men and women at vari- ous levels of physical activity. -appendix g presents the 2003 u.s. exchange system. -appendix h is an 8000-item food composition table compiled from the latest nutrient database assembled by axxya systems. -appendix i presents recommendations from the world health organization (who) and information for canadians the 2005 beyond the basics meal planning system and 2007 guidelines to healthy eat- ing and physical activities. -appendix j presents the healthy people 2010 nutri- tion-related objectives. -the inside covers the inside covers put commonly used information at your fin- gertips. -the front covers (pp. -a, b, and c) present the current nutrient recommenda- tions; the inside back cover (p. y on the left) features the daily values used on food labels and a glossary of nutrient measures; and the inside back cover (p. z on the right) shows the suggested weight ranges for various heights. -the pages just prior to the back cover (pp. -w-x) assist readers with calculations and conversions. -closing comments we have taken great care to provide accurate information and have included many references at the end of each chapter and highlight. -however, to keep the number of references manageable, many statements that appeared in previ- ous editions with references now appear without them. -all statements reflect current nutrition knowledge and the authors will supply references upon request. -in addition to supporting text statements, the end-of-chapter references provide readers with re- sources for finding a good overview or more details on the subject. -nutrition is a fas- cinating subject, and we hope our enthusiasm for it comes through on every page. -ellie whitney sharon rady rolfes april 2007 preface xix acknowledgments to produce a book requires the coordinated effort of a team of people and, no doubt, each team member has another team of support people as well. -we salute, with a big round of applause, everyone who has worked so diligently to ensure the quality of this book. -we thank our partners and friends, linda debruyne and fran webb, for their valuable consultations and contributions; working together over the past 20+ years has been a most wonderful experience. -we especially appreciate linda s research assistance on several chapters. -special thanks to our colleagues kathy pinna for her insightful comments, gail hammond for her canadian perspective, and sylvia crews for her revision of the aids to calculation section at the end of the book. -a thousand thank yous to beth magana, marni jay rolfes, and alex rodriguez for their careful attention to manuscript preparation and a multitude of other daily tasks. -we also thank the many people who have prepared the ancillaries that accom- pany this text: harry sitren for writing and enhancing the test bank; gail ham- mond, melissa langone, sharon stewart, lori turner, and daryle wane for contributing to the instructor s manual; eugene fenster for developing the webtu- tor; and lori turner for organizing the student study guide. -thanks also to donna kelly and to the folks at axxya for their assistance in creating the food composition appendix and developing the computerized diet analysis program that accompa- nies this book. -our special thanks to peter marshall, beth howe, and sandra craig for count- less creative contributions to previous editions and to our new editorial team for stepping in with enthusiasm peter adams for his leadership and support; nedah rose for her thoughtful suggestions and efficient analysis of reviews; cheryll linthicum for her artistic care of this project; jean blomo for her help with any and all requests; dusty friedman for her diligent attention to the innumerable details involved in production; jennifer somerville for her energetic efforts in marketing; ericka yeoman-saler for her dedication in developing our online animations and study tools; sarah d stair for her assistance in obtaining permissions; and elesha feldman for her competent coordination of ancillaries. -we also thank diane beasley for creatively designing these pages; roman barnes and norman baugher for selecting photographs and matthew farruggio for taking photographs that deliver nutrition messages beautifully; mary douglas for copyediting over 2000 manuscript pages; debra gates for proofreading close to 1000 final text pages; and erin taylor for composing a thorough and useful index. -to the hundreds of others involved in production and sales, we tip our hats in appreciation. -we are especially grateful to our friends and families for their continued encour- agement and support. -we also thank our many reviewers for their comments and contributions to this edition and all previous editions. -xx preface reviewers of understanding nutrition fernando agudelo-silva laney college nancy amy university of california, berkeley melody anacker montana state university janet anderson utah state university james baily university of tennessee, knoxville kathleen d. bauer montclair state university eugenia bearden clayton college and state university nancy becker portland state university patricia benarducci miami-dade community college margaret ann berry university of central oklahoma sharleen j. birkimer university of louisville debra boardley university of toledo jeanne s. boone palm beach community college ellen brennan san antonio college judi brooks eastern michigan university dorothy a. byrne university of texas at san antonio nancy canolty university of georgia leah carter bakersfield college mary ann cessna indiana university of pennsylvania jo carol chezum ball state university wendy cunningham california state university, sacramento jim daugherty glendale community college robert davidson brigham young university beth ellen diluglio palm beach community college robert disilvestro ohio state university marguerite dunne marist college brenda eissenstat pennsylvania state university eugene j. fenster longview community college cindy fitch west virginia university pam fletcher albuquerque technical vocational institute mary flynn brown university betty forbes west virginia university eileen ford university of pennsylvania william forsythe university of southern mississippi coni francis university of colorado health sciences center jean fremont simon fraser university julie rae friedman state university of new york, farmingdale trish froehlich palm beach community college patricia garrett university of tennessee, chattanooga francine genta cabrillo college michele ciccazzo florida international university leonard e. gerber university of rhode island donald d. clarke fordham college of fordham u. victoria getty indiana university ava craig sacramento city college jill golden orange coast college tina crook university of central arkansas gloria gonzalez, pensacola junior college kathleen gould townson university sandra m. gross west chester university bruce grossie texas woman s university deborah gustafson utah state university leon hageman burlington county college charlene hamilton university of delaware shelley hancock the university of alabama margaret hedley university of guelph carol a. heinz-bennett mesa community college kathryn henry hood college nancy hillquist elgin community college sharon himmelstein central new mexico community college carolyn hoffman central michigan university kim m. hohol mesa community college tracy horton university of colorado health sciences center andie hsueh texas woman s university eleanor b. huang orange coast college donna-jean hunt stephen f. austin university bernadette janas rutgers university michael jenkins kent state university carol johnston arizona state university connie jones northwestern state university of louisiana jayanthi kandiah ball state university pramod khosla wayne state university younghee kim bowling green state university beth kitchin university of alabama, birmingham kim kline university of texas at austin vicki kloosterhouse oakland community college susan m. krueger university of wisconsin, eau claire joanne kuchta texas a&m university michael lafontaine central connecticut state university betty larson concordia college dale larson johnson community college chunhye kim lee northern arizona university robert d. lee central michigan university anne leftwich university of central arkansas joseph leichter university of british columbia alan levine marywood university janet levins pensacola junior college lorraine lewis viterbo university samantha logan university of massachusetts, amherst jack logomarsino central michigan university elaine m. long boise state university kimberly lower collin county community college mary maciolek middlesex county college swarna mandali central missouri state university laura mcarthur east carolina university harriet mccoy university of arkansas, fayetteville bruce mcdonald university of manitoba lisa mckee new mexico state university marvin parent oakland community college padmini shankar georgia southern university kim mcmahon utah state university roman pawlak east carolina university nancy shearer cape cod community college mary mead university of california, berkeley linda peck university of findlay rhonda l. meyers lower columbia college lynn monahan-couch west chester university cynthia k. moore university of montevallo cynthia moore university of alabama william moore wytheville community college edith moran chicago state university mithia mukutmoni sierra college yasmin neggers university of alabama paula netherton tulsa junior college steven nizielski grand valley state university amy olson college of st. benedict, st. john s university anna page johnson county community college sarah panarello yakima valley community college susan s. percival university of florida erwina peterson yakima valley community college roseanne l. poole tallahassee community college julie priday centralia college stephanie raach rock valley college ann raymon chemeketa community college nuha f. rice portland community college & clackamas community college ramona g. rice georgia military college robin r. roach the university of memphis christian k. roberts university of california, los angeles sue roberts walla walla community college janet sass northern virginia community college tammy sakanashi santa rosa junior college linda shelton california state university, fresno linda shepherd college of saint benedict, saint john s university melissa shock university of central arkansas sandra shortt cedarville university denise signorelli community college of southern nevada brenda j. smith oklahoma state university mollie smith california state university, fresno luann soliah baylor university diana-marie spillman miami university, ohio karen stammen chapman university tammy stephenson university of kentucky sherry stewart universtiy of texas at dallas wendy stuhldreher slippery rock university of pennsylvania carla taylor university of manitoba preface xxi janet thompson university of waterloo michele trankina saint mary s university josephine umoren northern illinois university anne vanbeber texas christian university michelle l. vineyard university of tennessee, chattanooga eric vlahov university of tampa ava craig-waite sacramento city college janelle walter baylor university dana wassmer california state university, sacramento suzy weems stephen f. austin university d. katie wiedman university of saint francis garrison wilkes university of massachusetts, boston richard a. willis university of texas at austin stacie wing-gaia university of utah shahla m. wunderlich montclair state university lisa young new york university key sanders/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow how to: practice problems nutrition portfolio journal nutrition calculations: practice problems believe it or not, you have probably eaten at least 20,000 meals in your life. -without any conscious effort on your part, your body uses the nutrients from those foods to make all its components, fuel all its activities, and defend itself against diseases. -how successfully your body handles these tasks depends, in part, on your food choices. -nutritious food choices support healthy bodies. -an overview of nutrition welcome to the world of nutrition. -although you may not always have been aware of it, nutrition has played a significant role in your life. -and it will continue to affect you in major ways, depending on the foods you select. -every day, several times a day, you make food choices that influence your body s health for better or worse. -each day s choices may benefit or harm your health only a little, but when these choices are repeated over years and decades, the rewards or consequences become major. -that being the case, paying close attention to good eating habits now can bring you health benefits later. -conversely, carelessness about food choices can con- tribute to many chronic diseases prevalent in later life, including heart disease and cancer. -of course, some people will become ill or die young no matter what choices they make, and others will live long lives despite mak- ing poor choices. -for the majority of us, however, the food choices we make each and every day will benefit or impair our health in proportion to the wisdom of those choices. -although most people realize that their food habits affect their health, they of- ten choose foods for other reasons. -after all, foods bring to the table a variety of pleasures, traditions, and associations as well as nourishment. -the challenge, then, is to combine favorite foods and fun times with a nutritionally balanced diet. -food choices people decide what to eat, when to eat, and even whether to eat in highly personal ways, often based on behavioral or social motives rather than on an awareness of nu- trition s importance to health. -many different food choices can support good health, and an understanding of nutrition helps you make sensible selections more often. -personal preference as you might expect, the number one reason people choose foods is taste they like certain flavors. -two widely shared preferences are for the sweetness of sugar and the savoriness of salt. -liking high-fat foods also appears to be a universally common preference. -other preferences might be for the hot peppers c h a p t e r 1 chapter outline food choices the nutrients nutrients in foods and in the body the energy-yielding nutri- ents: carbohydrate, fat, and protein the vitamins the minerals water the science of nutrition conducting research analyzing research findings publishing research dietary reference intakes establish- ing nutrient recommendations estab- lishing energy recommendations using nutrient recommendations comparing nutrient recommendations nutrition assessment nutrition assessment of individuals nutrition assessment of populations diet and health chronic diseases risk factors for chronic diseases highlight 1 nutrition information and misinformation on the net and in the news in general, a chronic disease progresses slowly or with little change and lasts a long time. -by comparison, an acute dis- ease develops quickly, produces sharp symptoms, and runs a short course. -chronos = time acute = sharp nutrition: the science of foods and the nutrients and other substances they contain, and of their actions within the body (including ingestion, digestion, absorption, transport, metabolism, and excretion). -a broader definition includes the social, economic, cultural, and psychological implications of food and eating. -foods: products derived from plants or animals that can be taken into the body to yield energy and nutrients for the maintenance of life and the growth and repair of tissues. -diet: the foods and beverages a person eats and drinks. -3 4 chapter 1 an enjoyable way to learn about other cultures is to taste their ethnic foods. -common in mexican cooking or the curry spices of indian cuisine. -some research sug- gests that genetics may influence people s food preferences.1 habit people sometimes select foods out of habit. -they eat cereal every morning, for example, simply because they have always eaten cereal for breakfast. -eating a familiar food and not having to make any decisions can be comforting. -ethnic heritage or tradition among the strongest influences on food choices are ethnic heritage and tradition. -people eat the foods they grew up eating. -every country, and in fact every region of a country, has its own typical foods and ways of combining them into meals. -the american diet includes many ethnic foods from various countries, all adding va- riety to the diet. -this is most evident when eating out: 60 percent of u.s. restaurants (excluding fast-food places) have an ethnic emphasis, most commonly chinese, italian, or mexican. -social interactions most people enjoy companionship while eating. -it s fun to go out with friends for pizza or ice cream. -meals are social events, and sharing food is part of hospitality. -social customs invite people to accept food or drink offered by a host or shared by a group. -. -c n i , t i d e o t o h p / n o r a l l i b availability, convenience, and economy people eat foods that are accessible, quick and easy to prepare, and within their financial means. -today s consumers value convenience and are willing to spend more than half of their food budget on meals that require little, if any, further preparation.2 they frequently eat out, bring home ready-to-eat meals, or have food delivered. -even when they venture into the kitchen, they want to prepare a meal in 15 to 20 minutes, using less than a half dozen ingredients and those ingredients are often semiprepared foods, such as canned soups. -this emphasis on convenience limits food choices to the selections of- fered on menus and products designed for quick preparation. -whether decisions based on convenience meet a person s nutrition needs depends on the choices made. -eating a banana or a candy bar may be equally convenient, but the fruit offers more vitamins and minerals and less sugar and fat. -positive and negative associations people tend to like particular foods associ- ated with happy occasions such as hot dogs at ball games or cake and ice cream at birthday parties. -by the same token, people can develop aversions and dislike foods that they ate when they felt sick or that were forced on them.3 by using foods as rewards or punishments, parents may inadvertently teach their children to like and dislike certain foods. -emotional comfort some people cannot eat when they are emotionally upset. -others may eat in response to a variety of emotional stimuli for example, to re- lieve boredom or depression or to calm anxiety.4 a depressed person may choose to eat rather than to call a friend. -a person who has returned home from an exciting evening out may unwind with a late-night snack. -these people may find emotional comfort, in part, because foods can influence the brain s chemistry and the mind s response. -carbohydrates and alcohol, for example, tend to calm, whereas proteins and caffeine are more likely to activate. -eating in response to emotions can easily lead to overeating and obesity, but it may be appropriate at times. -for example, sharing food at times of bereavement serves both the giver s need to provide comfort and the receiver s need to be cared for and to interact with others, as well as to take nourishment. -values food choices may reflect people s religious beliefs, political views, or environ- mental concerns. -for example, many christians forgo meat during lent (the period prior to easter), jewish law includes an extensive set of dietary rules that govern the use of foods derived from animals, and muslims fast between sunrise and sunset dur- ing ramadan (the ninth month of the islamic calendar). -a concerned consumer may an overview of nutrition 5 to enhance your health, keep nutrition in mind when selecting foods. -functional foods may include whole foods, modified foods, or fortified foods. -boycott fruit picked by migrant workers who have been exploited. -people may buy vegetables from local farmers to save the fuel and environmental costs of foods shipped in from far away. -they may also select foods packaged in containers that can be reused or recycled. -some consumers accept or reject foods that have been irradiated or genetically modified, depending on their approval of these processes (see chapter and highlight 19 for a complete discussion). -body weight and image sometimes people select certain foods and supplements that they believe will improve their physical appearance and avoid those they believe might be detrimental. -such decisions can be beneficial when based on sound nutri- tion and fitness knowledge, but decisions based on fads or carried to extremes under- mine good health, as pointed out in later discussions of eating disorders (highlight 8) and dietary supplements commonly used by athletes (highlight 14). -nutrition and health benefits finally, of course, many consumers make food choices that will benefit health. -food manufacturers and restaurant chefs have re- sponded to scientific findings linking health with nutrition by offering an abun- dant selection of health-promoting foods and beverages. -foods that provide health benefits beyond their nutrient contributions are called functional foods.5 whole foods as natural and familiar as oatmeal or tomatoes are the simplest functional foods. -in other cases, foods have been modified to provide health ben- efits, perhaps by lowering the fat contents. -in still other cases, manufacturers have fortified foods by adding nutrients or phytochemicals that provide health ben- efits (see highlight 13). -examples of these functional foods include orange juice fortified with calcium to help build strong bones and margarine made with a plant sterol that lowers blood cholesterol. -consumers typically welcome new foods into their diets, provided that these foods are reasonably priced, clearly labeled, easy to find in the grocery store, and convenient to prepare. -these foods must also taste good as good as the tradi- tional choices. -of course, a person need not eat any of these special foods to en- joy a healthy diet; many regular foods provide numerous health benefits as well. -in fact, regular foods such as whole grains; vegetables and legumes; fruits; meats, fish, and poultry; and milk products are among the healthiest choices a person can make. -i s b r o c / y e l l e k s l e i r a in summary a person selects foods for a variety of reasons. -whatever those reasons may be, food choices influence health. -individual food selections neither make nor break a diet s healthfulness, but the balance of foods selected over time can make an important difference to health.6 for this reason, people are wise to think nutrition when making their food choices. -the nutrients biologically speaking, people eat to receive nourishment. -do you ever think of your- self as a biological being made of carefully arranged atoms, molecules, cells, tissues, and organs? -are you aware of the activity going on within your body even as you sit still? -the atoms, molecules, and cells of your body continually move and change, even though the structures of your tissues and organs and your external appearance remain relatively constant. -your skin, which has covered you since your birth, is re- placed entirely by new cells every seven years. -the fat beneath your skin is not the functional foods: foods that contain physiologically active compounds that provide health benefits beyond their nutrient contributions; sometimes called designer foods or nutraceuticals. -phytochemicals (fie-toe-kem-ih-cals): nonnutrient compounds found in plant- derived foods that have biological activity in the body. -phyto = plant 6 chapter 1 foods bring pleasure and nutrients. -as chapter 5 explains, most lipids are fats. -same fat that was there a year ago. -your oldest red blood cell is only 120 days old, and the entire lining of your digestive tract is renewed every 3 to 5 days. -to maintain your self, you must continually replenish, from foods, the energy and the nutrients you deplete as your body maintains itself. -nutrients in foods and in the body amazingly, our bodies can derive all the energy, structural materials, and regulating agents we need from the foods we eat. -this section introduces the nutrients that foods deliver and shows how they participate in the dynamic processes that keep people alive and well. -e l i f r e t s a m composition of foods chemical analysis of a food such as a tomato shows that it is composed primarily of water (95 percent). -most of the solid materials are carbohydrates, lipids, and proteins. -if you could remove these materials, you would find a tiny residue of vitamins, minerals, and other compounds. -water, carbohydrates, lipids, proteins, vitamins, and some of the minerals found in foods are nutrients substances the body uses for the growth, maintenance, and repair of its tissues. -this book focuses mostly on the nutrients, but foods contain other compounds as well fibers, phytochemicals, pigments, additives, alcohols, and others. -some are beneficial, some are neutral, and a few are harmful. -later sections of the book touch on these compounds and their significance. -composition of the body a complete chemical analysis of your body would show that it is made of materials similar to those found in foods (see figure 1-1). -a healthy 150-pound body contains about 90 pounds of water and about 20 to 45 pounds of fat. -the remaining pounds are mostly protein, carbohydrate, and the ma- jor minerals of the bones. -vitamins, other minerals, and incidental extras constitute a fraction of a pound. -figure 1-1 body composition of healthy-weight men and women the human body is made of compounds similar to those found in foods mostly water (60 percent) and some fat (13 to 21 percent for young men, 23 to 31 percent for young women), with carbohydrate, protein, vitamins, minerals, and other minor constituents making up the remainder. -(chapter 8 describes the health haz- ards of too little or too much body fat.) -key: % carbohydrates, proteins, vitamins, minerals in the body % fat in the body % water in the body energy: the capacity to do work. -the energy in food is chemical energy. -the body can convert this chemical energy to mechanical, electrical, or heat energy. -nutrients: chemical substances obtained from food and used in the body to provide energy, structural materials, and regulating agents to support growth, maintenance, and repair of the body s tissues. -nutrients may also reduce the risks of some diseases. -photodisc/getty images chemical composition of nutrients the simplest of the nutrients are the min- erals. -each mineral is a chemical element; its atoms are all alike. -as a result, its iden- tity never changes. -for example, iron may have different electrical charges, but the individual iron atoms remain the same when they are in a food, when a person eats the food, when the iron becomes part of a red blood cell, when the cell is broken down, and when the iron is lost from the body by excretion. -the next simplest nu- trient is water, a compound made of two elements hydrogen and oxygen. -miner- als and water are inorganic nutrients which means they do not contain carbon. -the other four classes of nutrients (carbohydrates, lipids, proteins, and vitamins) are more complex. -in addition to hydrogen and oxygen, they all contain carbon, an element found in all living things. -they are therefore called organic com- pounds (meaning, literally, alive ). -protein and some vitamins also contain nitro- gen and may contain other elements as well (see table 1-1). -essential nutrients the body can make some nutrients, but it cannot make all of them. -also, it makes some in insufficient quantities to meet its needs and, therefore, must obtain these nutrients from foods. -the nutrients that foods must supply are es- sential nutrients. -when used to refer to nutrients, the word essential means more than just necessary ; it means needed from outside the body normally, from foods. -the energy-yielding nutrients: carbohydrate, fat, and protein in the body, three organic nutrients can be used to provide energy: carbohydrate, fat, and protein. -in contrast to these energy-yielding nutrients, vitamins, min- erals, and water do not yield energy in the human body. -energy measured in kcalories the energy released from carbohydrates, fats, and proteins can be measured in calories tiny units of energy so small that a sin- gle apple provides tens of thousands of them. -to ease calculations, energy is expressed in 1000-calorie metric units known as kilocalories (shortened to kcalories, but com- monly called calories ). -when you read in popular books or magazines that an ap- ple provides 100 calories, it actually means 100 kcalories. -this book uses the term kcalorie and its abbreviation kcal throughout, as do other scientific books and jour- nals. -the how to on p. 8 provides a few tips on thinking metric. -table 1-1 elements in the six classes of nutrients notice that organic nutrients contain carbon. -carbon hydrogen oxygen nitrogen minerals inorganic nutrients minerals water organic nutrients carbohydrates lipids (fats) proteinsa vitaminsb asome proteins also contain the mineral sulfur. -bsome vitamins contain nitrogen; some contain minerals. -an overview of nutrition 7 in agriculture, organic farming refers to growing crops and raising livestock accord- ing to standards set by the u.s. department of agriculture (usda). -chapter 19 presents details. -carbohydrate, fat, and protein are sometimes called macronutrients because the body requires them in relatively large amounts (many grams daily). -in contrast, vi- tamins and minerals are micronutrients, required only in small amounts (milligrams or micrograms daily). -the international unit for measuring food energy is the joule, a measure of work energy. -to convert kcalories to kilojoules, multiply by 4.2; to convert kilojoules to kcalories, multiply by 0.24. inorganic: not containing carbon or pertaining to living things. -in = not organic: in chemistry, a substance or molecule containing carbon-carbon bonds or carbon-hydrogen bonds. -this definition excludes coal, diamonds, and a few carbon- containing compounds that contain only a single carbon and no hydrogen, such as carbon dioxide (co2), calcium carbonate (caco3), magnesium carbonate (mgco3), and sodium cyanide (nacn). -essential nutrients: nutrients a person must obtain from food because the body cannot make them for itself in sufficient quantity to meet physiological needs; also called indispensable nutrients. -about 40 nutrients are currently known to be essential for human beings. -energy-yielding nutrients: the nutrients that break down to yield energy the body can use: carbohydrate fat protein calories: units by which energy is measured. -food energy is measured in kilocalories (1000 calories equal 1 kilocalorie), abbreviated kcalories or kcal. -one kcalorie is the amount of heat necessary to raise the temperature of 1 kilogram (kg) of water 1 c. the scientific use of the term kcalorie is the same as the popular use of the term calorie. -8 chapter 1 how to think metric like other scientists, nutrition scientists use metric units of measure. -they measure food energy in kilocalories, people s height in centimeters, people s weight in kilograms, and the weights of foods and nutrients in grams, milligrams, or micrograms. -for ease in using these measures, it helps to remember that the prefixes on the grams imply 1000. for example, a kilogram is 1000 grams, a milligram is 1/1000 of a gram, and a micro- gram is 1/1000 of a milligram. -most food labels and many recipe books provide dual measures, listing both house- hold measures, such as cups, quarts, and teaspoons, and metric measures, such as milliliters, liters, and grams. -this practice gives people an opportunity to gradually learn to think metric. -a person might begin to think metric by simply observing the measure by noticing the amount of soda in a 2-liter bottle, for example. -through such experiences, a person can become familiar with a measure without having to do any conversions. -to facilitate communication, many mem- bers of the international scientific community have adopted a common system of measure- ment the international system of units (si). -in addition to using metric measures, the si establishes common units of measurement. -for example, the si unit for measuring food energy is the joule (not the kcalorie). -a joule is the amount of energy expended when 1 kilogram is moved 1 meter by a force of 1 newton. -the joule is thus a measure of work energy, whereas the kcalorie is a measure of heat energy. -while many scientists and jour- nals report their findings in kilojoules (kj), many others, particularly those in the united states, use kcalories (kcal). -to convert energy measures from kcalories to kilojoules, multiply by 4.2. for example, a 50-kcalorie cookie provides 210 kilojoules: 50 kcal (cid:2) 4.2 (cid:3) 210 kj exact conversion factors for these and other units of measure are in the aids to calculation section on the last two pages of the book. -volume: liters (l) 1 l (cid:3) 1000 milliliters (ml) 0.95 l (cid:3) 1 quart 1 ml (cid:3) 0.03 fluid ounces 240 ml (cid:3) 1 cup weight: grams (g) 1 g (cid:3) 1000 milligrams (mg) 1 g (cid:3) 0.04 ounce (oz) 1 oz (cid:3) 28.35 g (or 30 g) 100 g (cid:3) 31 2 oz 1 kilogram (kg) (cid:3) 1000 g 1 kg (cid:3) 2.2 pounds (lb) 454 g (cid:3) 1 lb a liter of liquid is approximately one u.s. quart. -(four liters are only about 5 percent more than a gallon.) -t i d e o t o h p / z e n i t r a m a i c i l e f / n o s r e t e p m o t , m r a h s a m o h t . -c n i c i h p a r g o t o h p t s e u q one cup is about 240 milliliters; a half-cup of liquid is about 120 milliliters. -z e n i t r a m a i c i l e f / t i d e o t o h p t i d e o t o h p / n a m e e r f y n o t a kilogram is slightly more than 2 lb; conversely, a pound is about 1 2 kg. -a half-cup of vegetables weighs about 100 grams; one pea weighs about 1 2 gram. -a 5-pound bag of potatoes weighs about 2 kilograms, and a 176-pound person weighs 80 kilograms. -to practice thinking metrically, log on to www.thomsonedu.com/thomsonnow, go to chapter 1, then go to how to. -foods with a high energy density help with weight gain, whereas those with a low energy density help with weight loss. -energy density: a measure of the energy a food provides relative to the amount of food (kcalories per gram). -energy from foods the amount of energy a food provides depends on how much carbohydrate, fat, and protein it contains. -when completely broken down in the body, a gram of carbohydrate yields about 4 kcalories of energy; a gram of protein also yields 4 kcalories; and a gram of fat yields 9 kcalories (see table 1-2). -fat, therefore, has a greater energy density than either carbohydrate or protein. -figure 1-2 compares the energy density of two breakfast options, and later chapters describe how consider- ing a food s energy density can help with weight management. -the how to on p. 9 explains how to calculate the energy available from foods. -one other substance contributes energy alcohol. -alcohol is not considered a nutrient because it interferes with the growth, maintenance, and repair of the body, but it does yield energy (7 kcalories per gram) when metabolized in the body. -(highlight 7 and chapter 18 present the potential harms and possible benefits of alcohol consumption.) -figure 1-2 energy density of two breakfast options compared gram for gram, ounce for ounce, and bite for bite, foods with a high energy density deliver more kcalories than foods with a low energy density. -both of these breakfast options provide 500 kcalories, but the cereal with milk, fruit salad, scrambled egg, turkey sausage, and toast with jam offers three times as much food as the doughnuts (based on weight); it has a lower energy density than the doughnuts. -selecting a variety of foods also helps to ensure nutrient adequacy. -an overview of nutrition 9 ) h t o b ( o i g g u r r a f w e h t t a m lower energy density higher energy density this 450-gram breakfast delivers 500 kcalories, for an energy density of 1.1 (500 kcal (cid:4) 450 g (cid:3) 1.1 kcal/g). -this 144-gram breakfast delivers 500 kcalories, for an energy density of 3.5 (500 kcal (cid:4) 144 g (cid:3) 3.5 kcal/g). -most foods contain all three energy-yielding nutrients, as well as water, vita- mins, minerals, and other substances. -for example, meat contains water, fat, vita- mins, and minerals as well as protein. -bread contains water, a trace of fat, a little protein, and some vitamins and minerals in addition to its carbohydrate. -only a few foods are exceptions to this rule, the common ones being sugar (pure carbohy- drate) and oil (essentially pure fat). -energy in the body the body uses the energy-yielding nutrients to fuel all its activ- ities. -when the body uses carbohydrate, fat, or protein for energy, the bonds between how to calculate the energy available from foods to calculate the energy available from a food, multiply the number of grams of carbohydrate, protein, and fat by 4, 4, and 9, respectively. -then add the results together. -for example, 1 slice of bread with 1 tablespoon of peanut butter on it contains 16 grams carbohydrate, 7 grams protein, and 9 grams fat: 16 g carbohydrate (cid:2) 4 kcal/g (cid:3) 64 kcal 7 g protein (cid:2) 4 kcal/g (cid:3) 28 kcal 9 g fat (cid:2) 9 kcal/g (cid:3) 81 kcal total (cid:3) 173 kcal from this information, you can calculate the percentage of kcalories each of the energy nutrients contributes to the total. -to determine the percentage of kcalories from fat, for example, divide the 81 fat kcalories by the total 173 kcalories: 81 fat kcal (cid:4) 173 total kcal (cid:3) 0.468 (rounded to 0.47) then multiply by 100 to get the percentage: 0.47 (cid:2) 100 (cid:3) 47% dietary recommendations that urge people to limit fat intake to 20 to 35 percent of kcalories refer to the day s total energy intake, not to individual foods. -still, if the proportion of fat in each food choice throughout a day exceeds 35 percent of kcalories, then the day s total surely will, too. -knowing that this snack provides 47 percent of its kcalories from fat alerts a person to the need to make lower-fat selections at other times that day. -to practice calculating the energy available from foods, log on to www.thomsonedu.com/ thomsonnow, go to chapter 1, then go to how to. -table 1-2 of energy nutrientsa kcalorie values nutrients carbohydrate fat protein energy (kcal/g) 4 9 4 note: alcohol contributes 7 kcalories per gram that can be used for energy, but it is not considered a nutrient because it interferes with the body s growth, maintenance, and repair. -a for those using kilojoules: 1 g carbohydrate (cid:3) 17 kj; 1 g protein (cid:3) 17 kj; 1 g fat (cid:3) 37 kj; and 1 g alcohol (cid:3) 29 kj. -10 chapter 1 the processes by which nutrients are broken down to yield energy or used to make body structures are known as metabolism (defined and described further in chapter 7). -the nutrient s atoms break. -as the bonds break, they release energy. -some of this en- ergy is released as heat, but some is used to send electrical impulses through the brain and nerves, to synthesize body compounds, and to move muscles. -thus the energy from food supports every activity from quiet thought to vigorous sports. -if the body does not use these nutrients to fuel its current activities, it rearranges them into storage compounds (such as body fat), to be used between meals and overnight when fresh energy supplies run low. -if more energy is consumed than expended, the re- sult is an increase in energy stores and weight gain. -similarly, if less energy is consumed than expended, the result is a decrease in energy stores and weight loss. -when consumed in excess of energy needs, alcohol, too, can be converted to body fat and stored. -when alcohol contributes a substantial portion of the energy in a person s diet, the harm it does far exceeds the problems of excess body fat. -(highlight 7 describes the effects of alcohol on health and nutrition.) -other roles of energy-yielding nutrients in addition to providing energy, carbohydrates, fats, and proteins provide the raw materials for building the body s tissues and regulating its many activities. -in fact, protein s role as a fuel source is rel- atively minor compared with both the other two nutrients and its other roles. -pro- teins are found in structures such as the muscles and skin and help to regulate activities such as digestion and energy metabolism. -the vitamins the vitamins are also organic, but they do not provide energy. -instead, they facili- tate the release of energy from carbohydrate, fat, and protein and participate in nu- merous other activities throughout the body. -each of the 13 different vitamins has its own special roles to play. -* one vitamin enables the eyes to see in dim light, another helps protect the lungs from air pollu- tion, and still another helps make the sex hormones among other things. -when you cut yourself, one vitamin helps stop the bleeding and another helps repair the skin. -vitamins busily help replace old red blood cells and the lining of the digestive tract. -almost every action in the body requires the assistance of vitamins. -vitamins can function only if they are intact, but because they are complex or- ganic molecules, they are vulnerable to destruction by heat, light, and chemical agents. -this is why the body handles them carefully, and why nutrition-wise cooks do, too. -the strategies of cooking vegetables at moderate temperatures for short times and using small amounts of water help to preserve the vitamins. -the minerals in the body, some minerals are put together in orderly arrays in such structures as bones and teeth. -minerals are also found in the fluids of the body, which influences fluid properties. -whatever their roles, minerals do not yield energy. -only 16 minerals are known to be essential in human nutrition. -** others are be- ing studied to determine whether they play significant roles in the human body. -still other minerals are environmental contaminants that displace the nutrient minerals from their workplaces in the body, disrupting body functions. -the prob- lems caused by contaminant minerals are described in chapter 13. because minerals are inorganic, they are indestructible and need not be handled with the special care that vitamins require. -minerals can, however, be bound by sub- stances that interfere with the body s ability to absorb them. -they can also be lost dur- ing food-refining processes or during cooking when they leach into water that is discarded. -vitamins: organic, essential nutrients required in small amounts by the body for health. -minerals: inorganic elements. -some minerals are essential nutrients required in small amounts by the body for health. -* the water-soluble vitamins are vitamin c and the eight b vitamins: thiamin, riboflavin, niacin, vitamins b6 and b12, folate, biotin, and pantothenic acid. -the fat-soluble vitamins are vitamins a, d, e, and k. the water-soluble vitamins are the subject of chapter 10 and the fat-soluble vitamins, of chapter 11. -** the major minerals are calcium, phosphorus, potassium, sodium, chloride, magnesium, and sul- fate. -the trace minerals are iron, iodine, zinc, chromium, selenium, fluoride, molybdenum, copper, and manganese. -chapters 12 and 13 are devoted to the major and trace minerals, respectively. -an overview of nutrition 11 water water, indispensable and abundant, provides the environment in which nearly all the body s activities are conducted. -it participates in many metabolic reac- tions and supplies the medium for transporting vital materials to cells and car- rying waste products away from them. -water is discussed fully in chapter 12, but it is mentioned in every chapter. -if you watch for it, you cannot help but be impressed by water s participation in all life processes. -in summary foods provide nutrients substances that support the growth, maintenance, and repair of the body s tissues. -the six classes of nutrients include: carbohydrates lipids (fats) proteins vitamins minerals water foods rich in the energy-yielding nutrients (carbohydrates, fats, and proteins) provide the major materials for building the body s tissues and yield energy for the body s use or storage. -energy is measured in kcalories. -vitamins, minerals, and water facilitate a variety of activities in the body. -water itself is an essential nutrient and natu- rally carries many minerals. -s i b r o c without exaggeration, nutrients provide the physical and metabolic basis for nearly all that we are and all that we do. -the next section introduces the science of nutrition with emphasis on the research methods scientists have used in uncov- ering the wonders of nutrition. -the science of nutrition the science of nutrition is the study of the nutrients and other substances in foods and the body s handling of them. -its foundation depends on several other sciences, including biology, biochemistry, and physiology. -as sciences go, nutrition is young, but as you can see from the size of this book, much has happened in nutrition s short life. -and it is currently entering a tremendous growth spurt as scientists apply knowledge gained from sequencing the human genome. -the integration of nutri- tion, genomics, and molecular biology has opened a whole new world of study called nutritional genomics the science of how nutrients affect the activities of genes and how genes affect the interactions between diet and disease.7 highlight 6 describes how nutritional genomics is shaping the science of nutrition, and exam- ples of nutrient gene interactions appear throughout later sections of the book. -conducting research consumers may depend on personal experience or reports from friends to gather information on nutrition, but researchers use the scientific method to guide their work (see figure 1-3 on p. 12). -as the figure shows, research always begins with a problem or a question. -for example, what foods or nutrients might protect against the common cold? -in search of an answer, scientists make an educated guess (hypothesis), such as foods rich in vitamin c reduce the number of common colds. -then they systematically conduct research studies to collect data that will test the hypothesis (see the glossary on p. 14 for definitions of research terms). -some examples of various types of research de- signs are presented in figure 1-4 (p. 13). -each type of study has strengths and weaknesses (see table 1-3 on p. 14). -consequently, some provide stronger evidence than others. -a personal account of an experience or event is an anecdote and is not accepted as reli- able scientific information. -anekdotos = unpublished genome (gee-nome): the full complement of genetic material (dna) in the chromosomes of a cell. -in human beings, the genome consists of 46 chromosomes. -the study of genomes is called genomics. -nutritional genomics: the science of how nutrients affect the activities of genes (nutrigenomics) and how genes affect the interactions between diet and disease (nutrigenetics). -12 chapter 1 figure 1-3 the scientific method research scientists follow the scientific method. -note that most research generates new questions, not final answers. -thus the sequence begins anew, and research continues in a somewhat cyclical way. -observation & question identify a problem to be solved or ask a specific question to be answered. -hypothesis & prediction formulate a hypothesis a tentative solution to the problem or answer to the question and make a prediction that can be tested. -experiment design a study and conduct the research to collect relevant data. -results & interpretations summarize, analyze, and interpret the data; draw conclusions. -hypothesis supported hypothesis not supported in attempting to discover whether a nutrient relieves symptoms or cures a disease, researchers deliberately manip- ulate one variable (for example, the amount of vitamin c in the diet) and measure any observed changes (perhaps the number of colds). -as much as possible, all other conditions are held constant. -the following paragraphs illustrate how this is accomplished. -controls in studies examining the effectiveness of vitamin c, researchers typically divide the subjects into two groups. -one group (the experimental group) receives a vitamin c supplement, and the other (the control group) does not. -re- searchers observe both groups to determine whether one group has fewer or shorter colds than the other. -the following discussion describes some of the pitfalls inherent in an exper- iment of this kind and ways to avoid them. -in sorting subjects into two groups, researchers must en- sure that each person has an equal chance of being assigned to either the experimental group or the control group. -this is accomplished by randomization; that is, the subjects are chosen randomly from the same population by flipping a coin or some other method involving chance. -randomiza- tion helps to ensure that results reflect the treatment and not factors that might influence the grouping of subjects. -importantly, the two groups of people must be similar and must have the same track record with respect to colds to rule out the possibility that observed differences in the rate, severity, or duration of colds might have occurred anyway. -if, for example, the control group would normally catch twice as many colds as the experimental group, then the findings prove nothing. -in experiments involving a nutrient, the diets of both groups must also be similar, especially with respect to the nu- trient being studied. -if those in the experimental group were receiving less vitamin c from their usual diet, then any ef- fects of the supplement may not be apparent. -theory develop a theory that integrates conclusions with those from numerous other studies. -new observations & questions sample size to ensure that chance variation between the two groups does not influence the results, the groups must be large. -for example, if one member of a group of five peo- ple catches a bad cold by chance, he will pull the whole group s average toward bad colds; but if one member of a group of 500 catches a bad cold, she will not unduly affect the group average. -statistical methods are used to determine whether differences between groups of various sizes support a hypothesis. -placebos if people who take vitamin c for colds believe it will cure them, their chances of recovery may improve. -taking anything believed to be beneficial may has- ten recovery. -this phenomenon, the result of expectations, is known as the placebo effect. -in experiments designed to determine vitamin c s effect on colds, this mind- body effect must be rigorously controlled. -severity of symptoms is often a subjective measure, and people who believe they are receiving treatment may report less severe symptoms. -one way experimenters control for the placebo effect is to give pills to all partic- ipants. -those in the experimental group, for example, receive pills containing vita- min c, and those in the control group receive a placebo pills of similar appearance and taste containing an inactive ingredient. -this way, the expecta- tions of both groups will be equal. -it is not necessary to convince all subjects that they are receiving vitamin c, but the extent of belief or unbelief must be the same in both groups. -a study conducted under these conditions is called a blind exper- an overview of nutrition 13 figure 1-4 examples of research designs epidemiological studies cross-sectional case-control cohort north atlantic ocean spain france slovenia croatia bosnia black sea italy montenegro albania greece turkey morocco algeria mediterranean sea tunisia syria lebanon israel jordan libya egypt researchers observe how much and what kinds of foods a group of people eat and how healthy those people are. -their findings identify factors that might influence the incidence of a disease in various populations. -example. -the people of the mediterranean region drink lots of wine, eat plenty of fat from olive oil, and have a lower incidence of heart disease than northern europeans and north americans. -s k c a t t a t r a e h . -c n i i s e t a c o s s a d n a n a m g r e b . -v . -l blood cholesterol researchers compare people who do and do not have a given condition such as a disease, closely matching them in age, gender, and other key variables so that differences in other factors will stand out. -these differences may account for the condition in the group that has it. -example. -people with goiter lack iodine in their diets. -researchers analyze data collected from a selected group of people (a cohort) at intervals over a certain period of time. -example. -data collected periodically over the past several decades from over 5000 people randomly selected from the town of framingham, massachusetts, in 1948 have revealed that the risk of heart attack increases as blood cholesterol increases. -experimental studies laboratory-based animal studies laboratory-based in vitro studies human intervention (or clinical) trials s e g a m i y t t e g / i l a n e b . -r i e c v r e s h c r a e s e r l a r u t l u c i r g a a d s u s e g a m i i y t t e g / c s d o t o h p researchers feed animals special diets that provide or omit specific nutrients and then observe any changes in health. -such studies test possible disease causes and treatments in a laboratory where all conditions can be controlled. -example. -mice fed a high-fat diet eat less food than mice given a lower-fat diet, so they receive the same number of kcalories but the mice eating the fat-rich diet become severely obese. -researchers examine the effects of a specific variable on a tissue, cell, or molecule isolated from a living organism. -example. -laboratory studies find that fish oils inhibit the growth and activity of the bacteria implicated in ulcer formation. -researchers ask people to adopt a new behavior (for example, eat a citrus fruit, take a vitamin c supplement, or exercise daily). -these trials help determine the effectiveness of such interventions on the development or prevention of disease. -example. -heart disease risk factors improve when men receive fresh-squeezed orange juice daily for two months compared with those on a diet low in vitamin c even when both groups follow a diet high in saturated fat. -iment that is, the subjects do not know (are blind to) whether they are members of the experimental group (receiving treatment) or the control group (receiving the placebo). -double blind when both the subjects and the researchers do not know which sub- jects are in which group, the study is called a double-blind experiment. -being fal- lible human beings and having an emotional and sometimes financial investment 14 chapter 1 knowledge about the nutrients and their effects on health comes from scientific study. -table 1-3 strengths and weaknesses of research designs type of research strengths weaknesses epidemiological studies determine the incidence and distribution of diseases in a population. -epidemiological studies include cross-sectional, case-control, and cohort (see figure 1-4). -laboratory-based studies explore the effects of a specific variable on a tissue, cell, or molecule. -laboratory-based studies are often conducted in test tubes (in vitro) or on animals. -human intervention or clini- cal trials involve human beings who follow a specified regimen. -e r o o m . -m g i a r c can narrow down the list of possible causes can raise questions to pur- sue through other types of studies cannot control variables that may influence the develop- ment or the prevention of a disease cannot prove cause and effect can control conditions can determine effects of a variable cannot apply results from test tubes or animals to human beings can control conditions (for cannot generalize findings the most part) can apply findings to some groups of human beings to all human beings cannot use certain treat- ments for clinical or ethical reasons in a successful outcome, researchers might record and interpret results with a bias in the expected direction. -to prevent such bias, the pills would be coded by a third party, who does not reveal to the experimenters which subjects were in which group until all results have been recorded. -analyzing research findings research findings must be analyzed and interpreted with an awareness of each study s limitations. -scientists must be cautious about drawing any conclusions until they have accumulated a body of evidence from multiple studies that have used var- ious types of research designs. -as evidence accumulates, scientists begin to develop a theory that integrates the various findings and explains the complex relationships. -g lossary of research terms blind experiment: an experiment in which the subjects do not know whether they are members of the experimental group or the control group. -control group: a group of individuals similar in all possible respects to the experimental group except for the treatment. -ideally, the control group receives a placebo while the experimental group receives a real treatment. -correlation (core-ee-lay-shun): the simultaneous increase, decrease, or change in two variables. -if a increases as b increases, or if a decreases as b decreases, the correlation is positive. -(this does not mean that a causes b or vice versa.) -if a increases as b decreases, or if a decreases as b increases, the correlation is negative. -(this does not mean that a prevents b or vice versa.) -some third factor may account for both a and b. assure that the scientific method was followed. -withhold judgment regarding the finding s validity. -double-blind experiment: an experiment in which neither the subjects nor the researchers know which subjects are members of the experimental group and which are serving as control subjects, until after the experiment is over. -experimental group: a group of individuals similar in all possible respects to the control group except for the treatment. -the experimental group receives the real treatment. -hypothesis (hi-poth-eh-sis): an unproven statement that tentatively explains the relationships between two or more variables. -peer review: a process in which a panel of scientists rigorously evaluates a research study to placebo (pla-see-bo): an inert, harmless medication given to provide comfort and hope; a sham treatment used in controlled research studies. -placebo effect: a change that occurs in reponse to expectations in the effectiveness of a treat- ment that actually has no pharmaceutical effects. -randomization (ran-dom-ih- zay-shun): a process of choosing the members of the experimental and control groups without bias. -replication (rep-lih-kay-shun): repeating an experiment and getting the same results. -the skeptical scientist, on hearing of a new, exciting finding, will ask, has it been replicated yet? -if it hasn t, the scientist will subjects: the people or animals participating in a research project. -theory: a tentative explanation that integrates many and diverse findings to further the understanding of a defined topic. -validity (va-lid-ih-tee): having the quality of being founded on fact or evidence. -variables: factors that change. -a variable may depend on another variable (for example, a child s height depends on his age), or it may be independent (for example, a child s height does not depend on the color of her eyes). -sometimes both variables correlate with a third variable (a child s height and eye color both depend on genetics). -an overview of nutrition 15 correlations and causes researchers often examine the relationships be- tween two or more variables for example, daily vitamin c intake and the number of colds or the duration and severity of cold symptoms. -importantly, re- searchers must be able to observe, measure, or verify the variables selected. -find- ings sometimes suggest no correlation between variables (regardless of the amount of vitamin c consumed, the number of colds remains the same). -other times, studies find either a positive correlation (the more vitamin c, the more colds) or a negative correlation (the more vitamin c, the fewer colds). -corre- lational evidence proves only that variables are associated, not that one is the cause of the other. -people often jump to conclusions when they notice correla- tions, but their conclusions are often wrong. -to actually prove that a causes b, scientists have to find evidence of the mechanism that is, an explanation of how a might cause b. cautious conclusions when researchers record and analyze the results of their experiments, they must exercise caution in their interpretation of the findings. -for example, in an epidemiological study, scientists may use a specific segment of the population say, men 18 to 30 years old. -when the scientists draw conclusions, they are careful not to generalize the findings to all people. -similarly, scientists per- forming research studies using animals are cautious in applying their findings to human beings. -conclusions from any one research study are always tentative and take into account findings from studies conducted by other scientists as well. -as ev- idence accumulates, scientists gain confidence about making recommendations that affect people s health and lives. -still, their statements are worded cautiously, such as a diet high in fruits and vegetables may protect against some cancers. -quite often, as scientists approach an answer to one research question, they raise several more questions, so future research projects are never lacking. -further scientific investigation then seeks to answer questions such as what substance or substances within fruits and vegetables provide protection? -if those substances turn out to be the vitamins found so abundantly in fresh produce, then, how much is needed to offer protection? -how do these vitamins protect against can- cer? -is it their action as antioxidant nutrients? -if not, might it be another ac- tion or even another substance that accounts for the protection fruits and vegetables provide against cancer? -(highlight 11 explores the answers to these questions and reviews recent research on antioxidant nutrients and disease.) -publishing research the findings from a research study are submitted to a board of reviewers composed of other scientists who rigorously evaluate the study to assure that the scientific method was followed a process known as peer review. -the reviewers critique the study s hypothesis, methodology, statistical significance, and conclusions. -if the re- viewers consider the conclusions to be well supported by the evidence that is, if the research has validity they endorse the work for publication in a scientific journal where others can read it. -this raises an important point regarding information found on the internet: much gets published without the rigorous scrutiny of peer re- view. -consequently, readers must assume greater responsibility for examining the data and conclusions presented often without the benefit of journal citations. -even when a new finding is published or released to the media, it is still only pre- liminary and not very meaningful by itself. -other scientists will need to confirm or disprove the findings through replication. -to be accepted into the body of nutri- tion knowledge, a finding must stand up to rigorous, repeated testing in experi- ments performed by several different researchers. -what we know in nutrition results from years of replicating study findings. -communicating the latest finding in its proper context without distorting or oversimplifying the message is a chal- lenge for scientists and journalists alike. -with each report from scientists, the field of nutrition changes a little each finding contributes another piece to the whole body of knowledge. -people who 16 chapter 1 don t let the dri alphabet soup of nutrient intake standards confuse you. -their names make sense when you learn their purposes. -dietary reference intakes (dri): a set of nutrient intake values for healthy people in the united states and canada. -these values are used for planning and assessing diets and include: estimated average requirements (ear) recommended dietary allowances (rda) adequate intakes (ai) tolerable upper intake levels (ul) requirement: the lowest continuing intake of a nutrient that will maintain a specified criterion of adequacy. -know how science works understand that single findings, like single frames in a movie, are just small parts of a larger story. -over years, the picture of what is true in nutrition gradually changes, and dietary recommendations change to reflect the current understanding of scientific research. -highlight 5 provides a detailed look at how dietary fat recommendations have evolved over the past several decades as re- searchers have uncovered the relationships between the various kinds of fat and their roles in supporting or harming health. -in summary scientists learn about nutrition by conducting experiments that follow the protocol of scientific research. -researchers take care to establish similar con- trol and experimental groups, large sample sizes, placebos, and blind treat- ments. -their findings must be reviewed and replicated by other scientists before being accepted as valid. -the characteristics of well-designed research have enabled scientists to study the ac- tions of nutrients in the body. -such research has laid the foundation for quantify- ing how much of each nutrient the body needs. -dietary reference intakes using the results of thousands of research studies, nutrition experts have produced a set of standards that define the amounts of energy, nutrients, other dietary compo- nents, and physical activity that best support health. -these recommendations are called dietary reference intakes (dri), and they reflect the collaborative efforts of researchers in both the united states and canada. -*8 the inside front covers of this book provide a handy reference for dri values. -s e g a m i y t t e g / c s i d o t o h p establishing nutrient recommendations the dri committee consists of highly qualified scientists who base their estimates of nutrient needs on careful examination and interpretation of scientific evidence. -these recommendations apply to healthy people and may not be appropriate for people with diseases that increase or decrease nutrient needs. -the next several para- graphs discuss specific aspects of how the committee goes about establishing the val- ues that make up the dri: estimated average requirements (ear) recommended dietary allowances (rda) adequate intakes (ai) tolerable upper intake levels (ul) estimated average requirements (ear) the committee reviews hundreds of research studies to determine the requirement for a nutrient how much is needed in the diet. -the committee selects a different criterion for each nutrient based on its various roles in performing activities in the body and in reducing disease risks. -an examination of all the available data reveals that each person s body is unique and has its own set of requirements. -men differ from women, and needs change as people grow from infancy through old age. -for this reason, the commit- tee clusters its recommendations for people into groups based on age and gender. -even so, the exact requirements for people of the same age and gender are likely to be different. -for example, person a might need 40 units of a particular nutrient each day; person b might need 35; and person c, 57. looking at enough people might reveal that their individual requirements fall into a symmetrical distribution, * the dri reports are produced by the food and nutrition board, institute of medicine of the national academies, with active involvement of scientists from canada. -with most near the midpoint and only a few at the extremes (see the left side of fig- ure 1-5). -using this information, the committee determines an estimated aver- age requirement (ear) for each nutrient the average amount that appears sufficient for half of the population. -in figure 1-5, the estimated average require- ment is shown as 45 units. -recommended dietary allowances (rda) once a nutrient requirement is es- tablished, the committee must decide what intake to recommend for everybody the recommended dietary allowance (rda). -as you can see by the distribution in figure 1-5, the estimated average requirement (shown in the figure as 45 units) is probably closest to everyone s need. -however, if people consumed exactly the aver- age requirement of a given nutrient each day, half of the population would develop deficiencies of that nutrient in figure 1-5, for example, person c would be among them. -recommendations are therefore set high enough above the estimated aver- age requirement to meet the needs of most healthy people. -small amounts above the daily requirement do no harm, whereas amounts below the requirement may lead to health problems. -when people s nutrient intakes are consistently deficient (less than the requirement), their nutrient stores decline, and over time this decline leads to poor health and deficiency symptoms. -therefore, to en- sure that the nutrient rda meet the needs of as many people as possible, the rda are set near the top end of the range of the population s estimated requirements. -in this example, a reasonable rda might be 63 units a day (see the right side of figure 1-5). -such a point can be calculated mathematically so that it covers about 98 percent of a population. -almost everybody including person c whose needs were higher than the average would be covered if they met this dietary goal. -rel- atively few people s requirements would exceed this recommendation, and even then, they wouldn t exceed by much. -adequate intakes (ai) for some nutrients, there is insufficient scientific evidence to determine an estimated average requirement (which is needed to set an rda). -in these cases, the committee establishes an adequate intake (ai) instead of an rda. -an ai reflects the average amount of a nutrient that a group of healthy peo- ple consumes. -like the rda, the ai may be used as nutrient goals for individuals. -figure 1-5 estimated average requirements (ear) and recommended dietary allowances (rda) compared estimated average requirement (ear) ear rda l e p o e p f o r e b m u n a b c l e p o e p f o r e b m u n a b c 20 30 40 50 60 70 20 30 40 50 60 70 daily requirement for nutrient x (units/day) daily requirement for nutrient x (units/day) the recommended dietary allowance (rda) for a nutrient (shown here in purple) is set well above the ear, covering about 98% of the population. -each square in the graph above represents a person with unique nutritional requirements. -(the text discusses three of these people a, b, and c.) some people require only a small amount of nutrient x and some require a lot. -most people, however, fall somewhere in the middle. -this amount that covers half of the population is called the estimated average requirement (ear) and is represented here by the red line. -an overview of nutrition 17 estimated average requirement (ear): the average daily amount of a nutrient that will maintain a specific biochemical or physiological function in half the healthy people of a given age and gender group. -recommended dietary allowance (rda): the average daily amount of a nutrient considered adequate to meet the known nutrient needs of practically all healthy people; a goal for dietary intake by individuals. -deficient: the amount of a nutrient below which almost all healthy people can be expected, over time, to experience deficiency symptoms. -adequate intake (ai): the average daily amount of a nutrient that appears sufficient to maintain a specified criterion; a value used as a guide for nutrient intake when an rda cannot be determined. -18 chapter 1 figure 1-6 accurate view of nutrient intakes inaccurate versus the rda or ai for a given nutrient represents a point that lies within a range of appropriate and reasonable intakes between toxicity and deficiency. -both of these recommendations are high enough to provide reserves in times of short-term dietary inadequacies, but not so high as to approach toxicity. -nutrient intakes above or below this range may be equally harmful. -danger of toxicity marginal safety safety e k a t n i rda danger marginal danger of deficiency inaccurate view accurate view tolerable upper intake level rda or ai estimated average requirement reference adults: men: 19 30 yr, 5 ft 10 in., and 154 lb women: 19 30 yr, 5 ft 4 in., and 126 lb tolerable upper intake level (ul): the maximum daily amount of a nutrient that appears safe for most healthy people and beyond which there is an increased risk of adverse health effects. -estimated energy requirement (eer): the average dietary energy intake that maintains energy balance and good health in a person of a given age, gender, weight, height, and level of physical activity. -acceptable macronutrient distribution ranges (amdr): ranges of intakes for the energy nutrients that provide adequate energy and nutrients and reduce the risk of chronic diseases. -although both the rda and the ai serve as nutrient intake goals for individu- als, their differences are noteworthy. -an rda for a given nutrient is based on enough scientific evidence to expect that the needs of almost all healthy people will be met. -an ai, on the other hand, must rely more heavily on scientific judgments because sufficient evidence is lacking. -the percentage of people covered by an ai is unknown; an ai is expected to exceed average requirements, but it may cover more or fewer people than an rda would cover (if an rda could be determined). -for these reasons, ai values are more tentative than rda. -the table on the inside front cover identifies which nutrients have an rda and which have an ai. -later chap- ters present the rda and ai values for the vitamins and minerals. -tolerable upper intake levels (ul) as mentioned earlier, the recommended in- takes for nutrients are generous, and they do not necessarily cover every individual for every nutrient. -nevertheless, it is probably best not to exceed these recommenda- tions by very much or very often. -individual tolerances for high doses of nutrients vary, and somewhere above the recommended intake is a point beyond which a nu- trient is likely to become toxic. -this point is known as the tolerable upper intake level (ul). -it is naive and inaccurate to think of recommendations as minimum amounts. -a more accurate view is to see a person s nutrient needs as falling within a range, with marginal and danger zones both below and above it (see figure 1-6). -paying attention to upper levels is particularly useful in guarding against the overconsumption of nutrients, which may occur when people use large-dose supple- ments and fortified foods regularly. -later chapters discuss the dangers associated with excessively high intakes of vitamins and minerals, and the inside front cover (page c) presents tables that include the upper-level values for selected nutrients. -establishing energy recommendations in contrast to the rda and ai values for nutrients, the recommendation for energy is not generous. -excess energy cannot be readily excreted and is eventually stored as body fat. -these reserves may be beneficial when food is scarce, but they can also lead to obesity and its associated health consequences. -estimated energy requirement (eer) the energy recommendation called the estimated energy requirement (eer) represents the average dietary energy in- take (kcalories per day) that will maintain energy balance in a person who has a healthy body weight and level of physical activity. -balance is key to the energy rec- ommendation. -enough energy is needed to sustain a healthy and active life, but too much energy can lead to weight gain and obesity. -because any amount in excess of en- ergy needs will result in weight gain, no upper level for energy has been determined. -acceptable macronutrient distribution ranges (amdr) people don t eat energy directly; they derive energy from foods containing carbohydrate, fat, and protein. -each of these three energy-yielding nutrients contributes to the total energy intake, and those contributions vary in relation to each other. -the dri committee has determined that the composition of a diet that provides adequate energy and nutrients and reduces the risk of chronic diseases is: 45 65 percent kcalories from carbohydrate 20 35 percent kcalories from fat 10 35 percent kcalories from protein these values are known as acceptable macronutrient distribution ranges (amdr). -using nutrient recommendations although the intent of nutrient recommendations seems simple, they are the subject of much misunderstanding and controversy. -perhaps the following facts will help put them in perspective: an overview of nutrition 19 a registered dietitian is a college- educated food and nutrition specialist who is qualified to evaluate people s nutritional health and needs. -see highlight 1 for more on what constitutes a nutrition expert. -nutrient recommendations from fao/who are provided in appendix i. -1. estimates of adequate energy and nutrient intakes apply to healthy people. -they need to be adjusted for malnourished people or those with medical problems who may require supplemented or restricted intakes. -2. recommendations are not minimum requirements, nor are they necessarily opti- mal intakes for all individuals. -recommendations can only target most of the people and cannot account for individual variations in nutrient needs yet. -given the recent explosion of knowledge about genetics, the day may be fast approaching when nutrition scientists will be able to determine an individual s optimal nutrient needs.9 until then, registered dietitians and other qualified health professionals can help determine if recommendations should be ad- justed to meet individual needs. -3. most nutrient goals are intended to be met through diets composed of a variety of foods whenever possible. -because foods contain mixtures of nutrients and nonnutrients, they deliver more than just those nutrients covered by the rec- ommendations. -excess intakes of vitamins and minerals are unlikely when they come from foods rather than supplements. -4. recommendations apply to average daily intakes. -trying to meet the recommen- dations for every nutrient every day is difficult and unnecessary. -the length of time over which a person s intake can deviate from the average without risk of deficiency or overdose varies for each nutrient, depending on how the body uses and stores the nutrient. -for most nutrients (such as thiamin and vitamin c), deprivation would lead to rapid development of deficiency symptoms (within days or weeks); for others (such as vitamin a and vitamin b12), deficien- cies would develop more slowly (over months or years). -5. each of the dri categories serves a unique purpose. -for example, the estimated average requirements are most appropriately used to develop and evaluate nu- trition programs for groups such as schoolchildren or military personnel. -the rda (or ai if an rda is not available) can be used to set goals for individuals. -tolerable upper intake levels serve as a reminder to keep nutrient intakes be- low amounts that increase the risk of toxicity not a common problem when nutrients derive from foods, but a real possibility for some nutrients if supple- ments are used regularly. -with these understandings, professionals can use the dri for a variety of purposes. -comparing nutrient recommendations at least 40 different nations and international organizations have published nutri- ent standards similar to those used in the united states and canada. -slight differ- ences may be apparent, reflecting differences both in the interpretation of the data from which the standards were derived and in the food habits and physical activi- ties of the populations they serve. -many countries use the recommendations developed by two international groups: fao (food and agriculture organization) and who (world health orga- nization). -the fao/who recommendations are considered sufficient to main- tain health in nearly all healthy people worldwide. -in summary the dietary reference intakes (dri) are a set of nutrient intake values that can be used to plan and evaluate diets for healthy people. -the estimated av- erage requirement (ear) defines the amount of a nutrient that supports a spe- cific function in the body for half of the population. -the recommended dietary allowance (rda) is based on the estimated average requirement and establishes a goal for dietary intake that will meet the needs of almost all 20 chapter 1 a peek inside the mouth provides clues to a person s nutrition status. -an inflamed tongue may indicate a b vitamin deficiency, and mot- tled teeth may reveal fluoride toxicity, for example. -malnutrition: any condition caused by excess or deficient food energy or nutrient intake or by an imbalance of nutrients. -mal = bad undernutrition: deficient energy or nutrients. -overnutrition: excess energy or nutrients. -nutrition assessment: a comprehensive analysis of a person s nutrition status that uses health, socioeconomic, drug, and diet histories; anthropometric measurements; physical examinations; and laboratory tests. -healthy people. -an adequate intake (ai) serves a similar purpose when an rda cannot be determined. -the estimated energy requirement (eer) defines the average amount of energy intake needed to maintain energy balance, and the acceptable macronutrient distribution ranges (amdr) define the propor- tions contributed by carbohydrate, fat, and protein to a healthy diet. -the tol- erable upper intake level (ul) establishes the highest amount that appears safe for regular consumption. -nutrition assessment what happens when a person doesn t get enough or gets too much of a nutrient or energy? -if the deficiency or excess is significant over time, the person exhibits signs of malnutrition. -with a deficiency of energy, the person may display the symptoms of undernutrition by becoming extremely thin, losing muscle tissue, and becoming prone to infection and disease. -with a deficiency of a nutrient, the person may expe- rience skin rashes, depression, hair loss, bleeding gums, muscle spasms, night blind- ness, or other symptoms. -with an excess of energy, the person may become obese and vulnerable to diseases associated with overnutrition such as heart disease and dia- betes. -with a sudden nutrient overdose, the person may experience hot flashes, yellowing skin, a rapid heart rate, low blood pressure, or other symptoms. -similarly, over time, regular intakes in excess of needs may also have adverse effects. -malnutrition symptoms such as diarrhea, skin rashes, and fa- tigue are easy to miss because they resemble the symptoms of other diseases. -but a person who has learned how to use assess- ment techniques to detect malnutrition can identify when these conditions are caused by poor nutrition and can recommend steps to correct it. -this discussion presents the basics of nutrition assess- ment; many more details are offered in later chapters and in ap- pendix e. nutrition assessment of individuals to prepare a nutrition assessment, a registered dietitian or other trained health care professional uses: historical information anthropometric data physical examinations laboratory tests i s b r o c / y h t r a c c m n n a e e d & m o t each of these methods involves collecting data in various ways and interpreting each finding in relation to the others to create a total picture. -historical information one step in evaluating nutrition status is to obtain infor- mation about a person s history with respect to health status, socioeconomic status, drug use, and diet. -the health history reflects a person s medical record and may re- veal a disease that interferes with the person s ability to eat or the body s use of nutri- ents. -the person s family history of major diseases is also noteworthy, especially for conditions such as heart disease that have a genetic tendency to run in families. -eco- nomic circumstances may show a financial inability to buy foods or inadequate kitchen facilities in which to prepare them. -social factors such as marital status, eth- nic background, and educational level also influence food choices and nutrition sta- tus. -a drug history, including all prescribed and over-the-counter medications as well as illegal substances, may highlight possible interactions that lead to nutrient defi- ciencies (as described in highlight 17). -a diet history that examines a person s intake figure 1-7 using the dri to assess the dietary intake of a healthy individual an overview of nutrition 21 intake probably adequate rda if a person s usual intake falls above the rda, the intake is probably adequate because the rda covers the needs of almost all people. -a usual intake that falls between the rda and the ear is more difficult to assess; the intake may be adequate, but the chances are greater or equal that it is inadequate. -of foods, beverages, and supple- ments may reveal either a sur- plus or inadequacy of nutrients or energy. -high f o t n e i r t u n ) y a d / s t i n u ( x intake possibly inadequate to take a diet history, the as- sessor collects data about the foods a person eats. -the data may be collected by recording the foods the person has eaten over a period of 24 hours, three days, or a week or more or by asking what foods the person typically eats and how much of each. -the days in the record must be fairly typical of the per- son s diet, and portion sizes must be recorded accurately. -to determine the amounts of nutri- ents consumed, the assessor usu- ally enters the foods and their portion sizes into a computer us- ing a diet analysis program. -this step can also be done man- ually by looking up each food in a table of food composition such as appendix h in this book. -the assessor then compares the calculated nutrient in- takes with the dri to determine the probability of adequacy (see figure 1-7).10 al- ternatively, the diet history might be compared against standards such as the usda food guide or dietary guidelines (described in chapter 2). -intake probably inadequate e k a t n a u s u ear low i l if the usual intake falls below the ear, it is probably inadequate. -an estimate of energy and nutrient intakes from a diet history, when combined with other sources of information, can help confirm or rule out the possibility of sus- pected nutrition problems. -a sufficient intake of a nutrient does not guarantee ad- equacy, and an insufficient intake does not always indicate a deficiency. -such findings, however, warn of possible problems. -anthropometric data a second technique that may help to reveal nutrition problems is taking anthropometric measures such as height and weight. -the as- sessor compares a person s measurements with standards specific for gender and age or with previous measures on the same individual. -(chapter 8 presents informa- tion on body weight and its standards.) -measurements taken periodically and compared with previous measurements reveal patterns and indicate trends in a person s overall nutrition status, but they provide little information about specific nutrients. -instead, measurements out of line with expectations may reveal such problems as growth failure in children, wasting or swelling of body tissues in adults, and obesity conditions that may re- flect energy or nutrient deficiencies or excesses. -physical examinations a third nutrition assessment technique is a physical exam- ination looking for clues to poor nutrition status. -every part of the body that can be in- spected may offer such clues: the hair, eyes, skin, posture, tongue, fingernails, and others. -the examination requires skill because many physical signs reflect more than one nutrient deficiency or toxicity or even nonnutrition conditions. -like the other as- sessment techniques, a physical examination alone does not yield firm conclusions. -instead, physical examinations reveal possible imbalances that must be confirmed by other assessment techniques, or they confirm results from other assessment measures. -laboratory tests a fourth way to detect a developing deficiency, imbalance, or toxicity is to take samples of blood or urine, analyze them in the laboratory, and compare the results with normal values for a similar population. -a goal of nutrition assessment may one day depend on measures of how a nutrient influences genetic activity within the cells, instead of quantities in the blood or other tissues. -anthropometric (an-throw-poe-met-rick): relating to measurement of the physical characteristics of the body, such as height and weight. -anthropos = human metric = measuring 22 chapter 1 figure 1-8 stages in the development of a nutrient deficiency internal changes precede outward signs of deficiencies. -however, outward signs of sickness need not appear before a person takes corrective measures. -laboratory tests can help determine nutrient status in the early stages. -what happens in the body which assessment methods reveal changes primary deficiency caused by inadequate diet or secondary deficiency caused by problem inside the body declining nutrient stores (subclinical) and abnormal functions inside the body (covert) diet history health history laboratory tests physical (overt) signs and symptoms physical examination and anthropometric measures assessment is to uncover early signs of malnutrition be- fore symptoms appear, and laboratory tests are most use- ful for this purpose. -in addition, they can confirm suspicions raised by other assessment methods. -iron, for example the mineral iron can be used to il- lustrate the stages in the development of a nutrient defi- ciency and the assessment techniques useful in detecting them. -the overt, or outward, signs of an iron deficiency appear at the end of a long sequence of events. -figure 1-8 describes what happens in the body as a nutrient de- ficiency progresses and shows which assessment meth- ods can reveal those changes. -first, the body has too little iron either because iron is lacking in the person s diet (a primary deficiency) or because the person s body doesn t absorb enough, excretes too much, or uses iron inefficiently (a second- ary deficiency). -a diet history provides clues to pri- mary deficiencies; a health history provides clues to secondary deficiencies. -next, the body begins to use up its stores of iron. -at this stage, the deficiency might be described as sub- clinical. -it exists as a covert condition, and although it might be detected by laboratory tests, no outward signs are apparent. -finally, the body s iron stores are exhausted. -now, it cannot make enough iron-containing red blood cells to replace those that are aging and dying. -iron is needed in red blood cells to carry oxygen to all the body s tis- sues. -when iron is lacking, fewer red blood cells are made, the new ones are pale and small, and every part of the body feels the effects of oxygen shortage. -now the overt symptoms of deficiency appear weakness, fatigue, pallor, and headaches, reflecting the iron-deficient state of the blood. -a physical examination will reveal these symptoms. -nutrition assessment of populations to assess a population s nutrition status, researchers conduct surveys using techniques similar to those used on individuals. -the data collected are then used by various agen- cies for numerous purposes, including the development of national health goals. -national nutrition surveys the national nutrition monitoring program coor- dinates the many nutrition-related surveys and research activities of various federal agencies. -the integration of two major national surveys provides comprehensive data efficiently.11 one survey collects data on the kinds and amounts of foods peo- ple eat. -* then researchers calculate the energy and nutrients in the foods and com- pare the amounts consumed with a standard. -the other survey examines the people themselves, using anthropometric measurements, physical examinations, and lab- oratory tests. -**12 the data provide valuable information on several nutrition-related conditions, such as growth retardation, heart disease, and nutrient deficiencies. -na- tional nutrition surveys often oversample high-risk groups (low-income families, pregnant women, adolescents, the elderly, african americans, and mexican ameri- cans) to glean an accurate estimate of their health and nutrition status. -the resulting wealth of information from the national nutrition surveys is used for a variety of purposes. -for example, congress uses this information to establish * this survey was formerly called the continuing survey of food intakes by individuals (csfii), con- ducted by the u.s. department of agriculture (usda). -** this survey is known as the national health and nutrition examination survey (nhanes), con- ducted by the u.s. department of health and human services (dhhs). -the new integrated survey is called what we eat in america. -overt (oh-vert): out in the open and easy to observe. -ouvrir = to open primary deficiency: a nutrient deficiency caused by inadequate dietary intake of a nutrient. -secondary deficiency: a nutrient deficiency caused by something other than an inadequate intake such as a disease condition or drug interaction that reduces absorption, accelerates use, hastens excretion, or destroys the nutrient. -subclinical deficiency: a deficiency in the early stages, before the outward signs have appeared. -covert (koh-vert): hidden, as if under covers. -couvrir = to cover public policy on nutrition education, food assistance programs, and the regulation of the food supply. -scientists use the information to establish research priorities. -the food industry uses these data to guide decisions in public relations and product development.13 the dietary reference intakes and other major reports that exam- ine the relationships between diet and health depend on information collected from these nutrition surveys. -these data also provide the basis for developing and monitoring national health goals. -national health goals healthy people is a program that identifies the nation s health priorities and guides policies that promote health and prevent disease. -at the start of each decade, the program sets goals for improving the nation s health during the following ten years. -the goals of healthy people 2010 focus on improving the quality of life and eliminating disparity in health among racial and ethnic groups. -14 nutrition is one of many focus areas, each with numerous objectives. -table 1-4 lists the nutrition and overweight objectives for 2010, and appendix j includes a table of nutrition-related objectives from other focus areas. -at mid-decade, the nation s progress toward meeting its nutrition and over- weight healthy people 2010 goals was somewhat bleak. -trends in overweight and obesity worsened. -objectives to eat more fruits, vegetables, and whole grains and to increase physical activity showed little or no improvement. -clearly, what we eat in america must change if we hope to meet the healthy people 2010 goals. -national trends what do we eat in america and how has it changed over the past 30 years?15 the short answer to both questions is a lot. -we eat more meals away from home, particularly at fast-food restaurants. -we eat larger portions. -we drink more sweetened beverages and eat more energy-dense, nutrient-poor foods such as candy and chips. -we snack frequently. -as a result of these dietary habits, our energy intake has risen and, consequently, so has the incidence of overweight and obesity. -overweight and obesity, in turn, profoundly influence our health as the next section explains. -table 1-4 healthy people 2010 nutrition and overweight objectives increase the proportion of adults who are at a healthy weight. -reduce the proportion of adults who are obese. -reduce the proportion of children and adolescents who are overweight or obese. -reduce growth retardation among low- income children under age 5 years. -increase the proportion of persons aged 2 years and older who consume at least two daily servings of fruit. -increase the proportion of persons aged 2 years and older who consume at least three daily servings of vegetables, with at least one-third being dark green or orange vegetables. -increase the proportion of persons aged 2 years and older who consume at least six daily servings of grain products, with at least three being whole grains. -increase the proportion of persons aged 2 years and older who consume less than 10 percent of kcalories from saturated fat. -increase the proportion of persons aged 2 years and older who consume no more than 30 percent of kcalories from total fat. -increase the proportion of persons aged 2 years and older who consume 2400 mg or less of sodium. -increase the proportion of persons aged 2 years and older who meet dietary recommen- dations for calcium. -reduce iron deficiency among young children, females of childbearing age, and pregnant females. -reduce anemia among low-income pregnant females in their third trimester. -increase the proportion of children and adolescents aged 6 to 19 years whose intake of meals and snacks at school contributes to good overall dietary quality. -increase the proportion of worksites that offer nutrition or weight management classes or counseling. -increase the proportion of physician office visits made by patients with a diagnosis of cardiovascular disease, diabetes, or hyper- lipidemia that include counseling or education related to diet and nutrition. -increase food security among u.s. households and in so doing reduce hunger. -note: nutrition and overweight is one of 28 focus areas, each with numerous objectives. -several of the other focus areas have nutrition-related objectives, and these are presented in appendix j. source: healthy people 2010, www.healthypeople.gov an overview of nutrition 23 s e g a m i y t t e g / h c s t i l o h c s t o c s e j surveys provide valuable information about the kinds of foods people eat. -healthy people: a national public health initiative under the jurisdiction of the u.s. department of health and human services (dhhs) that identifies the most significant preventable threats to health and focuses efforts toward eliminating them. -24 chapter 1 table 1-5 in the united states leading causes of death percentage of total deaths 1. heart disease 2. cancers 3. strokes 4. chronic lung diseases 5. accidents 6. diabetes mellitus 7. pneumonia and influenza 8. alzheimer s disease 9. kidney diseases 10. blood infections 28.0 22.7 6.4 5.2 4.5 3.0 2.7 2.6 1.7 1.4 note: the diseases highlighted in green have relationships with diet; yellow indicates a relationship with alcohol. -source: national center for health statistics: www.cdc.gov/nchs chronic diseases: diseases characterized by a slow progression and long duration. -examples include heart disease, cancer, and diabetes. -risk factor: a condition or behavior associated with an elevated frequency of a disease but not proved to be causal. -leading risk factors for chronic diseases include obesity, cigarette smoking, high blood pressure, high blood cholesterol, physical inactivity, and a diet high in saturated fats and low in vegetables, fruits, and whole grains. -in summary people become malnourished when they get too little or too much energy or nutrients. -deficiencies, excesses, and imbalances of nutrients lead to malnu- trition diseases. -to detect malnutrition in individuals, health care profession- als use four nutrition assessment methods. -reviewing dietary data and health information may suggest a nutrition problem in its earliest stages. -laboratory tests may detect it before it becomes overt, whereas anthropometrics and phys- ical examinations pick up on the problem only after it causes symptoms. -na- tional surveys use similar assessment methods to measure people s food consumption and to evaluate the nutrition status of populations. -diet and health diet has always played a vital role in supporting health. -early nutrition research fo- cused on identifying the nutrients in foods that would prevent such common dis- eases as rickets and scurvy, the vitamin d and vitamin c deficiency diseases. -with this knowledge, developed countries have successfully defended against nutrient de- ficiency diseases. -world hunger and nutrient deficiency diseases still pose a major health threat in developing countries, however, but not because of a lack of nutri- tion knowledge (as chapter 20 explains). -more recently, nutrition research has fo- cused on chronic diseases associated with energy and nutrient excesses. -once thought to be rich countries problems, chronic diseases have now become epi- demic in developing countries as well contributing to three out of five deaths worldwide.16 chronic diseases table 1-5 lists the ten leading causes of death in the united states. -these causes are stated as if a single condition such as heart disease caused death, but most chronic diseases arise from multiple factors over many years. -a person who died of heart dis- ease may have been overweight, had high blood pressure, been a cigarette smoker, and spent years eating a diet high in saturated fat and getting too little exercise. -of course, not all people who die of heart disease fit this description, nor do all people with these characteristics die of heart disease. -people who are overweight might die from the complications of diabetes instead, or those who smoke might die of cancer. -they might even die from something totally unrelated to any of these factors, such as an automobile accident. -still, statistical studies have shown that certain conditions and behaviors are linked to certain diseases. -notice that table 1-5 highlights five of the top six causes of death as having a link with diet or alcohol. -during the past 30 years, as knowledge about these diet and disease relationships grew, the death rates for four of these heart disease, can- cers, strokes, and accidents decreased.17 death rates for diabetes a chronic dis- ease closely associated with obesity increased. -risk factors for chronic diseases factors that increase or reduce the risk of developing chronic diseases can be identi- fied by analyzing statistical data. -a strong association between a risk factor and a disease means that when the factor is present, the likelihood of developing the dis- ease increases. -it does not mean that all people with the risk factor will develop the disease. -similarly, a lack of risk factors does not guarantee freedom from a given dis- ease. -on the average, though, the more risk factors in a person s life, the greater that person s chances of developing the disease. -conversely, the fewer risk factors in a person s life, the better the chances for good health. -an overview of nutrition 25 table 1-6 deaths in the united states factors contributing to factors tobacco poor diet/inactivity alcohol microbial agents toxic agents motor vehicles firearms sexual behavior illicit drugs percentage of deaths 18 15 4 3 2 2 1 1 1 source: a. h. mokdad and coauthors, actual causes of death in the united states, 2000, journal of the american medical association 291 (2004): 1238 1245, with corrections from journal of the american medical association 293 (2005): 298. s e g a m i y t t e g / c s i d o t o h p cigarette smoking is responsible for almost one of every five deaths each year. -physical activity can be both fun and beneficial. -risk factors persist risk factors tend to persist over time. -without interven- tion, a young adult with high blood pressure will most likely continue to have high blood pressure as an older adult, for example. -thus, to minimize the dam- age, early intervention is most effective. -risk factors cluster risk factors tend to cluster. -for example, a person who is obese may be physically inactive, have high blood pressure, and have high blood cholesterol all risk factors associated with heart disease. -intervention that focuses on one risk factor often benefits the others as well. -for example, physical activity can help reduce weight. -the physical activity and weight loss will, in turn, help to lower blood pressure and blood cholesterol. -risk factors in perspective the most prominent factor contributing to death in the united states is tobacco use, followed closely by diet and activity patterns, and then alcohol use (see table 1-6).18 risk factors such as smoking, poor dietary habits, physical inactivity, and alcohol consumption are personal behaviors that can be changed. -decisions to not smoke, to eat a well-balanced diet, to engage in regular physical activity, and to drink alcohol in moderation (if at all) improve the likeli- hood that a person will enjoy good health. -other risk factors, such as genetics, gen- der, and age, also play important roles in the development of chronic diseases, but they cannot be changed. -health recommendations acknowledge the influence of such factors on the development of disease, but they must focus on the factors that are changeable. -for the two out of three americans who do not smoke or drink al- cohol excessively, the one choice that can influence long-term health prospects more than any other is diet. -in summary within the range set by genetics, a person s choice of diet influences long-term health. -diet has no influence on some diseases but is linked closely to others. -personal life choices, such as engaging in physical activity and using tobacco or alcohol, also affect health for the better or worse. -26 chapter 1 the next several chapters provide many more details about nutrients and how they support health. -whenever appropriate, the discussion shows how diet influences each of today s major diseases. -dietary recommendations appear again and again, as each nutrient s relationships with health is explored. -most people who follow the recommendations will benefit and can enjoy good health into their later years. -www.thomsonedu.com/thomsonnow nutrition portfolio each chapter in this book ends with simple nutrition portfolio activities that invite you to review key messages and consider whether your personal choices are meeting the dietary goals introduced in the text. -by keeping a journal of these nutrition portfolio assignments, you can examine how your knowledge and behaviors change as you progress in your study of nutrition. -your food choices play a key role in keeping you healthy and reducing your risk of chronic diseases. -identify the factors that most influence your food choices for meals and snacks. -list the chronic disease risk factors and conditions (listed in the definition of risk factors on p. 24) that you or members of your family have. -describe lifestyle changes you can make to improve your chances of enjoying good health. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 1, then to nutrition on the net. -search for nutrition at the u.s. government health and nutrition information sites: www.healthfinder.gov or www.nutrition.gov view healthy people 2010: www.healthypeople.gov visit the food and nutrition section of the healthy living area in health canada: www.hc-sc.gc.ca learn about the national nutrition survey: www.cdc.gov/nchs/nhanes.htm learn more about basic science research from the national science foundation and research!america: www.nsf.gov and researchamerica.org get information from the food surveys research group: www.barc.usda.gov/bhnrc/foodsurvey visit the food and nutrition center of the mayo clinic: review the dietary reference intakes: www.nap.edu www.mayohealth.org review nutrition recommendations from the food and create a chart of your family health history at the u.s. agriculture organization and the world health organiza- tion: www.fao.org and www.who.org surgeon general s site: familyhistory.hhs.gov nutrition calculations for additional practice, log on to www.thomsonedu.com/thomsonnow. -go to chapter 1, then to nutrition calculations. -an overview of nutrition 27 several chapters end with problems to give you practice in doing simple nutrition-related calculations. -although the situations are hypothetical, the numbers are real, and calcu- lating the answers (check them on p. 29) provides a valuable nutrition lesson. -once you have mastered these examples, you will be prepared to examine your own food choices. -be sure to show your calculations for each problem. -1. calculate the energy provided by a food s energy-nutrient contents. -a cup of fried rice contains 5 grams protein, 30 grams carbohydrate, and 11 grams fat. -a. how many kcalories does the rice provide from these energy nutrients? -(cid:3) (cid:3) (cid:3) kcal protein kcal carbohydrate kcal fat total (cid:3) kcal b. what percentage of the energy in the fried rice comes from each of the energy-yielding nutrients? -(cid:3) (cid:3) (cid:3) % kcal from protein % kcal from carbohydrate % kcal from fat total (cid:3) % study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review this chapter. -you will find the answers in the discussions on the pages provided. -1. give several reasons (and examples) why people make the food choices that they do. -(p. 3 5) 2. what is a nutrient? -name the six classes of nutrients found in foods. -what is an essential nutrient? -(pp. -6 7) 3. which nutrients are inorganic, and which are organic? -discuss the significance of that distinction. -(pp. -7, 10) 4. which nutrients yield energy, and how much energy do they yield per gram? -how is energy measured? -(pp. -7 10) 5. describe how alcohol resembles nutrients. -why is alco- hol not considered a nutrient? -(pp. -8, 10) 6. what is the science of nutrition? -describe the types of research studies and methods used in acquiring nutrition information. -(pp. -11 16) 7. explain how variables might be correlational but not causal. -(p. 15) 8. what are the dri? -who develops the dri? -to whom do they apply? -how are they used? -in your description, identify the categories of dri and indicate how they are related. -(pp. -16 19) 9. what judgment factors are involved in setting the en- ergy and nutrient recommendations? -(pp. -17 18) note: the total should add up to 100%; 99% or 101% due to rounding is also acceptable. -c. calculate how many of the 146 kcalories provided by a 12-ounce can of beer come from alcohol, if the beer contains 1 gram protein and 13 grams carbohydrate. -(note: the remaining kcalories de- rive from alcohol.) -1 g protein (cid:3) 13 g carbohydrate (cid:3) (cid:3) kcal protein kcal carbohydrate kcal alcohol how many grams of alcohol does this represent? -g alcohol 2. even a little nutrition knowledge can help you identify some bogus claims. -consider an advertisement for a new super supplement that claims the product provides 15 grams protein and 10 kcalories per dose. -is this possible? -why or why not? -(cid:3) kcal 10. what happens when people get either too little or too much energy or nutrients? -define malnutrition, under- nutrition, and overnutrition. -describe the four methods used to detect energy and nutrient deficiencies and ex- cesses. -(pp. -20 22) 11. what methods are used in nutrition surveys? -what kinds of information can these surveys provide? -(pp. -22 23) 12. describe risk factors and their relationships to disease. -(pp. -24 25) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 29. -1. when people eat the foods typical of their families or geographic region, their choices are influenced by: a. habit. -b. nutrition. -c. personal preference. -d. ethnic heritage or tradition. -2. both the human body and many foods are composed mostly of: a. fat. -b. water. -c. minerals. -d. proteins. -28 chapter 1 3. the inorganic nutrients are: a. proteins and fats. -b. vitamins and minerals. -c. minerals and water. -d. vitamins and proteins. -4. the energy-yielding nutrients are: a. fats, minerals, and water. -b. minerals, proteins, and vitamins. -c. carbohydrates, fats, and vitamins. -d. carbohydrates, fats, and proteins. -5. studies of populations that reveal correlations between dietary habits and disease incidence are: a. clinical trials. -b. laboratory studies. -c. case-control studies. -d. epidemiological studies. -6. an experiment in which neither the researchers nor the subjects know who is receiving the treatment is known as: a. double blind. -b. double control. -c. blind variable. -d. placebo control. -7. an rda represents the: a. highest amount of a nutrient that appears safe for most healthy people. -b. lowest amount of a nutrient that will maintain a specified criterion of adequacy. -c. average amount of a nutrient considered adequate to meet the known nutrient needs of practically all healthy people. -d. average amount of a nutrient that will maintain a specific biochemical or physiological function in half the people. -8. historical information, physical examinations, laboratory tests, and anthropometric measures are: a. techniques used in diet planning. -b. steps used in the scientific method. -c. approaches used in disease prevention. -d. methods used in a nutrition assessment. -9. a deficiency caused by an inadequate dietary intake is a(n): a. overt deficiency. -b. covert deficiency. -c. primary deficiency. -d. secondary deficiency. -10. behaviors such as smoking, dietary habits, physical activ- ity, and alcohol consumption that influence the develop- ment of disease are known as: a. risk factors. -b. chronic causes. -c. preventive agents. -d. disease descriptors. -references 1. j. a. mennella, m. y. pepino, and d. r. reed, genetic and environmental determi- nants of bitter perception and sweet prefer- ences, pediatrics 115 (2005): e216. -2. j. e. tillotson, our ready-prepared, ready-to- eat nation, nutrition today 37 (2002): 36-38. -3. d. benton, role of parents in the determi- nation of the food preferences of children and the development of obesity, interna- tional journal of obesity related metabolic disorders 28 (2004): 858-869. -4. l. canetti, e. bachar, and e. m. berry, food and emotion, behavioural processes 60 (2002): 157-164. -5. position of the american dietetic associa- tion: functional foods, journal of the ameri- can dietetic association 104 (2004): 814-826. -6. position of the american dietetic associa- tion: total diet approach to communicating food and nutrition information, journal of the american dietetic association 102 (2002): 100-108. -7. l. afman and m. m ller, nutrigenomics: from molecular nutrition to prevention of disease, journal of the american dietetic association 106 (2006): 569-576; j. ordovas and v. mooser, nutrigenomics and nutrige- netics, current opinion in lipidology 15 (2005): 101-108; d. shattuck, nutritional genomics, journal of the american dietetic association 103 (2003): 16, 18; p. trayhurn, nutritional genomics- nutrigenomics, british journal of nutrition 89 (2003): 1-2. -8. committee on dietary reference intakes, dietary reference intakes for water, potassium, sodium, chloride, and sulfate (washington, d.c.: national academies press, 2005); committee on dietary reference intakes, dietary reference intakes for energy, carbohy- drate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (washington, d.c.: national academies press, 2005); commit- tee on dietary reference intakes, dietary reference intakes for vitamin a, vitamin k, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc (washington, d.c.: national academy press, 2001); committee on dietary reference intakes, dietary refer- ence intakes for vitamin c, vitamin e, sele- nium, and carotenoids (washington, d.c.: national academy press, 2000); committee on dietary reference intakes, dietary refer- ence intakes for thiamin, riboflavin, niacin, vitamin b6, folate, vitamin b12, pantothenic acid, biotin, and choline (washington, d.c.: national academy press, 1998); committee on dietary reference intakes, dietary refer- ence intakes for calcium, phosphorus, magne- sium, vitamin d, and fluoride (washington, d.c.: national academy press, 1997). -10. s. p. murphy, s. i. barr, and m. i. poos, using the new dietary reference intakes to assess diets: a map to the maze, nutrition reviews 60 (2002): 267-275. -12. j. dwyer and coauthors, collection of food and dietary supplement intake data: what we eat in america-nhanes, journal of nutrition 133 (2003): 590s-600s. -13. s. j. crockett and coauthors, nutrition monitoring application in the food indus- try, nutrition today 37 (2002): 130-135. -15. r. r. briefel and c. l. johnson, secular trends in dietary intake in the united states, annual review of nutrition 24 (2004): 401-431. -16. b. m. popkin, global nutrition dynamics: the world is shifting rapidly toward a diet linked with noncommunicable diseases, american journal of clinical nutrition 84 (2006): 289-298; d. yach and coauthors, the global burden of chronic diseases: overcom- ing impediments to prevention and control, journal of the american medical association 291 (2004): 2616-2622. -17. a. jemal and coauthors, trends in the leading causes of death in the united states, 1970-2002, journal of the american medical association 294 (2005): 1255-1259. -18. a. h. mokdad and coauthors, actual causes of death in the united states, 2000, journal of the american medical association 291 (2004): 1238-1245. an overview of nutrition 29 2. no. -15 g protein (cid:2) 4 kcal/g = 60 kcal study questions (multiple choice) 1. d 9. c 2. b 3. c 4. d 5. d 6. a 7. c 8. d 10. a answers nutrition calculations 1. a. -5 g protein (cid:2) 4 kcal/g = 20 kcal protein 30 g carbohydrate (cid:2) 4 kcal/g = 120 kcal carbohydrate 11 g fat (cid:2) 9 kcal/g = 99 kcal fat total = 239 kcal b. -20 kcal (cid:4) 239 kcal (cid:2) 100 = 8.4% kcal from protein 120 kcal(cid:4) 239 kcal (cid:2) 100 = 50.2% kcal from carbohydrate 99 kcal (cid:4) 239 kcal (cid:2) 100 = 41.4% kcal from fat total = 100%. -c. 1 g protein = 4 kcal protein 13 g carbohydrate = 52 kcal carbohydrate 146 total kcal (cid:5) 56 kcal (protein (cid:6) carbohydrate) = 90 kcal alcohol 90 kcal alcohol (cid:4) 7 g/kcal = 12.9 g alcohol highlight 1 nutrition information and misinformation on the net and in the news how can people distinguish valid nutrition in- formation from misinformation? -one excellent approach is to notice who is providing the in- formation. -the who behind the information is not always evident, though, especially in the world of electronic media. -keep in mind that people develop cd-roms and create websites on the internet, just as people write books and report the news. -in all cases, consumers need to determine whether the person is qualified to provide nutrition information. -this highlight begins by examining the unique potential as well as the problems of relying on the internet and the media for nutrition information. -it continues with a discussion of how to identify reliable nutrition information that applies to all resources, including the internet and the news. -(the glossary on p. 32 de- fines related terms.) -nutrition on the net got a question? -the internet has an answer. -the internet offers endless opportunities to obtain high-quality information, but it also delivers an abundance of incomplete, misleading, or inaccu- rate information.1 simply put: anyone can publish anything. -with hundreds of millions of websites on the world wide web, searching for nutrition information can be an overwhelming experience much like walking into an enormous bookstore with millions of books, magazines, newspapers, and videos. -and like a bookstore, the internet offers no guarantees of the accuracy of the information found there much of which is pure fiction. -when using the internet, keep in mind that the quality of health-related information available covers a broad range.2 you must evaluate websites for their accuracy, just like every other source. -the accompanying how to provides tips for determin- ing whether a website is reliable. -one of the most trustworthy sites used by scientists and others is the national library of medicine s pubmed, which provides free access to over 10 million abstracts (short descriptions) of research papers published in scientific journals around the world. -many abstracts provide links to websites where full articles are available. -figure h1-1 introduces this valuable resource. -did you receive the e-mail warning about costa rican bananas causing the disease necrotizing fasciitis ? -if so, you ve been 30 e k a t o t o h p / p i s b / y s s e j / t n e r u a l scammed by internet misinformation. -when nutrition information arrives in unsolicited e- mails, be suspicious if: the person sending it to you didn t write it and you cannot determine who did or if that person is a nutrition expert the phrase forward this to everyone you know appears the phrase this is not a hoax appears; chances are that it is the news is sensational and you ve never heard about it from legitimate sources the language is emphatic and the text is sprinkled with capitalized words and exclamation marks no references are given or, if present, are of questionable validity when examined the message has been debunked on websites such as www.quackwatch.org or www.urbanlegends.com nutrition in the news consumers get much of their nutrition information from televi- sion news and magazine reports, which have heightened aware- ness of how diet influences the development of diseases. -consumers benefit from news coverage of nutrition when they learn to make lifestyle changes that will improve their health. -sometimes, however, when magazine articles or television pro- grams report nutrition trends, they mislead consumers and create confusion. -they often tell a lopsided story based on a few testi- monials instead of presenting the results of research studies or a balance of expert opinions. -tight deadlines and limited understanding sometimes make it difficult to provide a thorough report. -hungry for the latest news, the media often report scientific findings prematurely without benefit of careful interpretation, replication, and peer review.3 usually, the reports present findings from a single, re- cently released study, making the news current and controver- sial. -consequently, the public receives diet and health news quickly, but not always in perspective. -reporters may twist in- conclusive findings into meaningful discoveries when pres- nutrition information and misinformation on the net and in the news 31 sured to write catchy headlines and sensa- tional stories. -as a result, surprising new findings seem to contradict one another, and con- sumers feel frustrated and betrayed. -occa- sionally, the reports are downright false, but more often the apparent contradic- tions are simply the normal result of sci- ence at work. -a single study contributes to the big picture, but when viewed alone, it can easily distort the image. -to be mean- ingful, the conclusions of any study must be presented cautiously within the context of other research findings. -identifying nutrition experts how to determine whether a website is reliable to determine whether a website offers reliable nutrition information, ask the following questions: who? -who is responsible for the site? -is it staffed by qualified professionals? -look for the authors names and credentials. -have experts reviewed the content for accuracy? -when? -when was the site last updated? -because nutrition is an ever-changing science, sites need to be dated and up- dated frequently. -where? -where is the information com- ing from? -the three letters following the dot in a web address identify the site s affiliation. -addresses ending in gov (government), edu (educational insti- tute), and org (organization) generally provide reliable information; com (commercial) sites represent businesses and, depending on their qualifications and integrity, may or may not offer de- pendable information. -why? -why is the site giving you this information? -is the site providing a public service or selling a product? -many com- mercial sites provide accurate information, but some do not. -when money is the prime motivation, be aware that the information may be biased. -if you are satisfied with the answers to all of the questions above, then ask this final question: what? -what is the message, and is it in line with other reliable sources? -informa- tion that contradicts common knowledge should be questioned. -many reliable sites provide links to other sites to facilitate your quest for knowledge, but this provi- sion alone does not guarantee a reputable intention. -be aware that any site can link to any other site without permission. -regardless of whether the medium is elec- tronic, print, or video, consumers need to ask whether the person behind the informa- tion is qualified to speak on nutrition. -if the creator of an internet website recommends eating three pineapples a day to lose weight, a trainer at the gym praises a high-protein diet, or a health-store clerk suggests an herbal supplement, should you believe these people? -can you distinguish between accurate news reports and infomercials on television? -have you noticed that many televised nutrition messages are presented by celebrities, fit- ness experts, psychologists, food editors, and chefs that is, almost anyone except a dietitian? -when you are confused or need sound dietary ad- vice, whom should you ask? -in the curricula for all health care professionals: physicians, nurses, physician s assistants, dental hygienists, physical and occupa- tional therapists, social workers, and all others who provide ser- vices directly to clients. -when these professionals understand the relevance of nutrition in the treatment and prevention of disease and have command of reliable nutrition information, then all the people they serve will also be better informed. -figure h1-1 pubmed (www.pubmed.gov): internet resource for scientific nutrition references physicians and other health care professionals many people turn to physicians or other health care professionals for dietary ad- vice, expecting them to know about all health-related matters. -but are they the best sources of accurate and current in- formation on nutrition? -only about 30 percent of all medical schools in the united states require students to take a separate nutrition course; less than half require the minimum 25 hours of nutri- tion instruction recommended by the national academy of sciences.4 by com- parison, most students reading this text are taking a nutrition class that provides an average of 45 hours of instruction. -the american dietetic associa- tion (ada) asserts that standardized nutrition education should be included the u.s. national library of medicine s pubmed website offers tutorials to help teach beginners to use the search system effectively. -often, simply visiting the site, typing a query in the search for box, and clicking go will yield satisfactory results. -for example, to find research concerning calcium and bone health, typing cal- cium bone nets over 30,000 results. -try setting limits on dates, types of articles, lan- guages, and other criteria to obtain a more manageable number of abstracts to peruse. -type search terms here refine the search by setting limits use tutorial resources to answer questions search pubmed for national library of medicine nlm go clear about entrez text version entrez pubmed overview help/faq tutorial new/noteworthy limits preview/index history clipboard details (cid:129) enter one or more search terms, or click preview/index for advanced searching. -(cid:129) enter author names as smith jc. -initials are optional. -(cid:129) enter journal titles in full or as medline abbreviations. -use the journals database to find journal titles. -32 highlight 1 g lossary accredited: approved; in the case of medical centers or universities, certified by an agency recognized by the u.s. department of education. -american dietetic association (ada): the professional organization of dietitians in the united states. -the canadian equivalent is dietitians of canada, which operates similarly. -certified nutritionists or certified nutritional consultants or certified nutrition therapists: a person who has been granted a document declaring his or her authority as a nutrition professional; see also nutritionalist. -correspondence schools: schools that offer courses and degrees by mail. -some correspondence schools are accredited; others are not. -dietetic technician: a person who has completed a minimum of an associate s degree from an accredited university or college and an approved dietetic technician program that includes a supervised practice experience. -see also dietetic technician, registered (dtr). -internet (the net): a worldwide network of millions of comput- ers linked together to share information. -dietetic technician, registered (dtr): a dietetic technician who has passed a national examination and maintains registration through continuing professional education. -dietitian: a person trained in nutrition, food science, and diet planning. -see also registered dietitian. -dtr: see dietetic technician, registered. -fraudulent: the promotion, for financial gain, of devices, treatments, services, plans, or products (including diets and supplements) that alter or claim to alter a human condition without proof of safety or effectiveness. -(the word quackery comes from the term quacksalver, meaning a person who quacks loudly about a miracle product a lotion or a salve.) -license to practice: permission under state or federal law, granted on meeting specified criteria, to use a certain title (such as dietitian) and offer certain services. -licensed dietitians may use the initials ld after their names. -misinformation: false or misleading information. -nutritionist: a person who specializes in the study of nutrition. -note that this definition does not specify qualifications and may apply not only to registered dietitians but also to self-described experts whose training is questionable. -most states have licensing laws that define the scope of practice for those calling themselves nutritionists. -public health dietitians: dietitians who specialize in providing nutrition services through organized community efforts. -rd: see registered dietitian. -registered dietitian (rd): a person who has completed a minimum of a bachelor s degree from an accredited university or college, has completed approved course work and a supervised practice program, has passed a national examination, and maintains registration through continuing professional education. -registration: listing; with respect to health professionals, listing with a professional organization that requires specific course work, experience, and passing of an examination. -websites: internet resources composed of text and graphic files, each with a unique url (uniform resource locator) that names the site (for example, www.usda.gov). -world wide web (the web, commonly abbreviated www): a graphical subset of the internet. -most health care professionals appreciate the connections be- tween health and nutrition. -those who have specialized in clinical nu- trition are especially well qualified to speak on the subject. -few, however, have the time or experience to develop diet plans and pro- vide detailed diet instructions for clients. -often they wisely refer clients to a qualified nutrition expert a registered dietitian (rd). -registered dietitians (rd) a registered dietitian (rd) has the educational background neces- sary to deliver reliable nutrition advice and care.5 to become an rd, a person must earn an undergraduate degree requiring about 60 semester hours in nutrition, food science, and other related subjects; complete a year s clinical internship or the equivalent; pass a national examination administered by the ada; and main- tain up-to-date knowledge and registration by participating in required continuing education activities such as attending semi- nars, taking courses, or writing professional papers. -some states allow anyone to use the title dietitian or nutrition- ist, but others allow only an rd or people with specified qualifica- tions to call themselves dietitians. -many states provide a further guarantee: a state registration, certification, or license to practice. -in this way, states identify people who have met minimal standards of education and experience. -still, these state standards may fall short of those defining an rd. -similarly, some alternative educational pro- grams qualify their graduates as certified nutritionists, certified nutritional consultants, or certified nutrition therapists terms that sound authoritative but lack the credentials of an rd.6 dietitians perform a multitude of duties in many settings in most communities. -they work in the food industry, pharmaceutical com- panies, home health agencies, long-term care institutions, private practice, public health departments, research centers, education settings, fitness centers, and hospitals. -depending on their work settings, dietitians can assume a number of different job responsi- bilities and positions. -in hospitals, administrative dietitians manage the foodservice system; clinical dietitians provide client care; and nutrition support team dietitians coordinate nutrition care with other health care professionals. -in the food industry, dietitians con- duct research, develop products, and market services. -public health dietitians who work in government-funded agencies play a key role in delivering nutrition services to people in the community. -among their many roles, public health dietitians help plan, coordinate, and evaluate food assistance programs; act as consultants to other agencies; manage finances; and much more. -other dietary employees in some facilities, a dietetic technician assists registered dieti- tians in both administrative and clinical responsibilities. -a dietetic technician has been educated and trained to work under the guid- ance of a registered dietitian; upon passing a national examination, the title changes to dietetic technician, registered (dtr). -nutrition information and misinformation on the net and in the news 33 in addition to the dietetic technician, other dietary employees may include clerks, aides, cooks, porters, and other assistants. -these dietary employees do not have extensive formal training in nutrition, and their ability to provide accurate information may be limited. -identifying fake credentials in contrast to registered dietitians, thousands of peo- ple obtain fake nutrition degrees and claim to be nutri- tion consultants or doctors of nutrimedicine. -these and other such titles may sound meaningful, but most of these people lack the established credentials and training of an ada-sanctioned dietitian. -if you look closely, you can see signs of their fake expertise. -consider educational background, for example. -the minimum standards of education for a dietitian specify a bachelor of science (bs) degree in food science and human nutrition or related fields from an accredited college or university. -* such a degree generally requires four to five years of study. -in contrast, a fake nutrition expert may display a degree from a six-month corre- spondence course. -such a degree simply falls short. -in some cases, businesses posing as legitimate corre- spondence schools offer even less they sell certifi- cates to anyone who pays the fees. -to obtain these degrees, a candidate need not attend any classes, read any books, or pass any examinations. -how to find credible sources of nutrition information government agencies, volunteer associations, consumer groups, and profes- sional organizations provide consumers with reliable health and nutrition infor- mation. -credible sources of nutrition information include: nutrition and food science departments at a university or community college local agencies such as the health department or county cooperative extension service government health agencies such as: department of agriculture (usda) www.usda.gov department of health and human services (dhhs) www.os.dhhs.gov food and drug administration (fda) www.fda.gov health canada www.hc-sc.gc.ca/nutrition volunteer health agencies such as: american cancer society american diabetes association www.cancer.org www.diabetes.org american heart association www.americanheart.org reputable consumer groups such as: american council on science and health www.acsh.org federal citizen information center international food information council www.pueblo.gsa.gov ific.org professional health organizations such as: american dietetic assocation american medical association dietitians of canada journals such as: www.eatright.org www.ama-assn.org www.dietitians.ca american journal of clinical nutrition www.ajcn.org new england journal of medicine nutrition reviews www.nejm.org www.ilsi.org to safeguard educational quality, an accrediting agency recognized by the u.s. department of education (doe) certifies that certain schools meet criteria established to ensure that an institution provides complete and accurate schooling. -unfortu- nately, fake nutrition degrees are available from schools accredited by more than 30 phony accrediting agencies. -acquiring false creden- tials is especially easy today, with fraudulent businesses operating via the internet. -knowing the qualifications of someone who provides nutrition information can help you determine whether that person s advice might be harmful or helpful. -don t be afraid to ask for credentials. -the accompanying how to lists credible sources of nutrition in- formation. -red flags of nutrition quackery figure h1-2 (p. 34) features eight red flags consumers can use to identify nutrition misinformation. -sales of unproven and dangerous products have always been a concern, but the inter- net now provides merchants with an easy and inexpensive way to reach millions of customers around the world. -because of the dif- ficulty in regulating the internet, fraudulent and illegal sales of medical products have hit a bonanza. -as is the case with the air, no one owns the internet, and similarly, no one has control over the pollution. -countries have different laws regarding sales of drugs, dietary supplements, and other health products, but apply- ing these laws to the internet marketplace is almost impossible. -even if illegal activities could be defined and identified, finding the person responsible for a particular website is not always possible. -websites can open and close in a blink of a cursor. -now, more than ever, consumers must heed the caution buyer beware. -in summary, when you hear nutrition news, consider its source. -ask yourself these two questions: is the person providing the infor- mation qualified to speak on nutrition? -is the information based on valid scientific research? -if not, find a better source. -after all, your health depends on it. -* to ensure the quality and continued improvement of nutrition and dietetics education programs, an ada agency known as the commission on accreditation for dietetics education (cade) establishes and enforces eligibility requirements and accreditation standards for programs preparing students for careers as registered dietitians or dietetic technicians. -programs meeting those standards are accredited by cade. -34 highlight 1 figure h1-2 red flags of nutrition quackery satisfaction guaranteed marketers may make generous promises, but consumers won t be able to collect on them. -one product does it all no one product can possibly treat such a diverse array of conditions. -time tested such findings would be widely publicized and accepted by health professionals. -quick and easy fixes even proven treatments take time to be effective. -natural natural is not necessarily better or safer; any product that is strong enough to be effective is strong enough to cause side effects. -instant recovery, back to your everyday schedule best pills around revolutionary product, based on ancient medicine guaranteed! -or your money back! -cures gout, ulcers, diabetes and cancer beats the hunger stimulation point (hsp) the natural way to becoming a better you money grabbing drug companies further corporate means my friends feel good as new! -paranoid accusations and this product s company doesn t want money? -at least the drug company has scientific research proving the safety and effectiveness of its products. -personal testimonials hearsay is the weakest form of evidence. -meaningless medical jargon phony terms hide the lack of scientific proof. -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 1, then to highlights nutrition on the net. -visit the national council against health fraud: www.ncahf.org find a registered dietitian in your area from the ameri- can dietetic association: www.eatright.org find a nutrition professional in canada from the dieti- tians of canada: www.dietitians.ca find out whether a correspondence school is accredited from the distance education and training council s accrediting commission: www.detc.org find useful and reliable health information from the health on the net foundation: www.hon.ch find out whether a school is properly accredited for a dietetics degree from the american dietetic association: www.eatright.org/cade obtain a listing of accredited institutions, profession- ally accredited programs, and candidates for accredita- tion from the american council on education: www.acenet.edu learn more about quackery from stephen barrett s quackwatch: www.quackwatch.org check out health-related hoaxes and urban legends: www.cdc.gov/hoax_rumors.htm and www.urbanlegends.com/ find reliable research articles: www.pubmed.gov nutrition information and misinformation on the net and in the news 35 references 1. position of the american dietetic associa- tion: food and nutrition misinformation, journal of the american dietetic association 106 (2006): 601-607. -2. g. eysenbach and coauthors, empirical studies assessing the quality of health infor- mation for consumers on the world wide web: a systematic review, journal of the american medical association 287 (2002): 2691-2700. -3. l. m. schwartz, s. woloshin, and l. baczek, media coverage of scientific meetings: too much, too soon? -journal of the american medical association 287 (2002): 2859-2863. -4. k. m. adams and coauthors, status of nutri- tion education in medical schools, american journal of clinical nutrition 83 (2006): 941s-944s. -5. position of the american dietetic associa- tion: the roles of registered dieticians and dietetic technicians, registered in health promotion and disease prevention, journal of the american dietetic association 106 (2006): 1875-1884. -6. nutritionist imposters and how to spot them, nutrition and the m.d., september 2004, pp. -4-6. photolink/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow how to: practice problems nutrition portfolio journal nutrition calculations: practice problems you make food choices deciding what to eat and how much to eat more than 1000 times every year. -we eat so frequently that it s easy to choose a meal without giving any thought to its nutrient contributions or health consequences. -even when we want to make healthy choices, we may not know which foods to select or how much to consume. -with a few tools and tips, you can learn to plan a healthy diet. -planning a healthy diet chapter 1 explained that the body s many activities are supported by the nutrients delivered by the foods people eat. -food choices made over years influence the body s health, and consistently poor choices increase the risks of developing chronic diseases. -this chapter shows how a person can select c h a p t e r 2 chapter outline principles and guidelines diet-plan- ning principles dietary guidelines for americans diet-planning guides usda food guide exchange lists putting the plan into action from guidelines to groceries food labels the ingredient list serving sizes nutrition facts the daily values nutrient claims health claims structure-function claims consumer education from the tens of thousands of available foods to create a diet that supports highlight 2 vegetarian diets health. -fortunately, most foods provide several nutrients, so one trick for wise diet planning is to select a combination of foods that deliver a full ar- ray of nutrients. -this chapter begins by introducing the diet-planning prin- ciples and dietary guidelines that assist people in selecting foods that will deliver nutrients without excess energy (kcalories). -principles and guidelines how well you nourish yourself does not depend on the selection of any one food. -in- stead, it depends on the selection of many different foods at numerous meals over days, months, and years. -diet-planning principles and dietary guidelines are key concepts to keep in mind whenever you are selecting foods whether shopping at the grocery store, choosing from a restaurant menu, or preparing a home-cooked meal. -diet-planning principles diet planners have developed several ways to select foods. -whatever plan or combi- nation of plans they use, though, they keep in mind the six basic diet-planning prin- ciples listed in the margin. -adequacy adequacy means that the diet provides sufficient energy and enough of all the nutrients to meet the needs of healthy people. -take the essential nutrient iron, for example. -because the body loses some iron each day, people have to re- place it by eating foods that contain iron. -a person whose diet fails to provide enough iron-rich foods may develop the symptoms of iron-deficiency anemia: the person may feel weak, tired, and listless; have frequent headaches; and find that even the smallest amount of muscular work brings disabling fatigue. -to prevent these deficiency symptoms, a person must include foods that supply adequate iron. -the same is true for all the other essential nutrients introduced in chapter 1. diet-planning principles: adequacy balance kcalorie (energy) control nutrient density moderation variety adequacy (dietary): providing all the essential nutrients, fiber, and energy in amounts sufficient to maintain health. -37 38 chapter 2 to ensure an adequate and balanced diet, eat a variety of foods daily, choosing different foods from each group. -balance in the diet helps to ensure adequacy. -nutrient density promotes adequacy and kcalorie control. -to practice comparing the nutrient density of foods, log on to www.thomsonedu.com/thomsonnow, go to chapter 2, then go to how to. -balance (dietary): providing foods in proportion to each other and in proportion to the body s needs. -kcalorie (energy) control: management of food energy intake. -nutrient density: a measure of the nutrients a food provides relative to the energy it provides. -the more nutrients and the fewer kcalories, the higher the nutrient density. -. -c n i s o i d t u s a r a l o p balance the art of balancing the diet involves consuming enough but not too much of each type of food. -the essential minerals calcium and iron, taken to- gether, illustrate the importance of dietary balance. -meats, fish, and poultry are rich in iron but poor in calcium. -conversely, milk and milk products are rich in cal- cium but poor in iron. -use some meat or meat alternates for iron; use some milk and milk products for calcium; and save some space for other foods, too, because a diet consisting of milk and meat alone would not be adequate. -for the other nutrients, people need whole grains, vegetables, and fruits. -kcalorie (energy) control designing an adequate diet without overeating re- quires careful planning. -once again, balance plays a key role. -the amount of en- ergy coming into the body from foods should balance with the amount of energy being used by the body to sustain its metabolic and physical activities. -upsetting this balance leads to gains or losses in body weight. -the discussion of energy balance and weight control in chapters 8 and 9 examines this issue in more detail, but the key to kcalorie control is to select foods of high nutrient density. -nutrient density to eat well without overeating, select foods that deliver the most nutrients for the least food energy. -consider foods containing calcium, for example. -you can get about 300 milligrams of calcium from either 11/2 ounces of cheddar cheese or 1 cup of fat-free milk, but the cheese delivers about twice as much food en- ergy (kcalories) as the milk. -the fat-free milk, then, is twice as calcium dense as the cheddar cheese; it offers the same amount of calcium for half the kcalories. -both foods are excellent choices for adequacy s sake alone, but to achieve adequacy while controlling kcalories, the fat-free milk is the better choice. -(alternatively, a person could select a low-fat cheddar cheese.) -the many bar graphs that appear in chap- ters 10 through 13 highlight the most nutrient-dense choices, and the accompany- ing how to describes how to compare foods based on nutrient density. -how to compare foods based on nutrient density one way to evaluate foods is simply to notice their nutrient contribution per serv- ing: 1 cup of milk provides about 300 mil- ligrams of calcium, and 1 2 cup of fresh, cooked turnip greens provides about 100 milligrams. -thus a serving of milk offers three times as much calcium as a serving of turnip greens. -to get 300 milligrams of calcium, a person could choose either 1 cup of milk or 11 2 cups of turnip greens. -another valuable way to evaluate foods is to consider their nutrient den- sity their nutrient contribution per kcalo- rie. -fat-free milk delivers about 85 kcalories with its 300 milligrams of cal- cium. -to calculate the nutrient density, di- vide milligrams by kcalories: 300 mg calcium 85 kcal (cid:2) 3.5 mg per kcal do the same for the fresh turnip greens, which provide 15 kcalories with the 100 milligrams of calcium: 100 mg calcium 15 kcal (cid:2) 6.7 mg per kcal the more milligrams per kcalorie, the greater the nutrient density. -turnip greens are more calcium dense than milk. -they provide more calcium per kcalorie than milk, but milk offers more calcium per serving. -both approaches offer valu- able information, especially when com- bined with a realistic appraisal. -what matters most is which are you more likely to consume 11 2 cups of turnip greens or 1 cup of milk? -you can get 300 milligrams of calcium from either, but the greens will save you about 40 kcalories (the savings would be even greater if you usually use whole milk). -keep in mind, too, that calcium is only one of the many nutrients that foods pro- vide. -similar calculations for protein, for example, would show that fat-free milk provides more protein both per kcalorie and per serving than turnip greens that is, milk is more protein dense. -combining variety with nutrient density helps to en- sure the adequacy of all nutrients. -just like a person who has to pay for rent, food, clothes, and tuition on a limited budget, we have to obtain iron, calcium, and all the other essential nutrients on a limited energy allowance. -success depends on getting many nutrients for each kcalo- rie dollar. -for example, a can of cola and a handful of grapes may both provide about the same number of kcalories, but the grapes deliver many more nutrients. -a person who makes nutrient-dense choices, such as fruit instead of cola, can meet daily nutrient needs on a lower energy budget. -such choices support good health. -foods that are notably low in nutrient density such as potato chips, candy, and colas are sometimes called empty-kcalorie foods. -the kcalories these foods provide are called empty because they deliver energy (from sugar, fat, or both) with little, or no, protein, vitamins, or minerals. -moderation foods rich in fat and sugar provide enjoyment and energy but rela- tively few nutrients. -in addition, they promote weight gain when eaten in excess. -a person practicing moderation eats such foods only on occasion and regularly se- lects foods low in solid fats and added sugars, a practice that automatically im- proves nutrient density. -returning to the example of cheddar cheese versus fat-free milk, the fat-free milk not only offers the same amount of calcium for less energy, but it also contains far less fat than the cheese. -variety a diet may have all of the virtues just described and still lack variety, if a person eats the same foods day after day. -people should select foods from each of the food groups daily and vary their choices within each food group from day to day for several reasons. -first, different foods within the same group contain different arrays of nutrients. -among the fruits, for example, strawberries are especially rich in vita- min c while apricots are rich in vitamin a. variety improves nutrient adequacy.1 second, no food is guaranteed entirely free of substances that, in excess, could be harmful. -the strawberries might contain trace amounts of one contaminant, the apricots another. -by alternating fruit choices, a person will ingest very little of either contaminant. -(contamination of foods is discussed in chapter 19.) -third, as the adage goes, variety is the spice of life. -a person who eats beans frequently can enjoy pinto beans in mexican burritos today, garbanzo beans in greek salad tomorrow, and baked beans with barbecued chicken on the weekend. -eating nutritious meals need never be boring. -dietary guidelines for americans what should a person eat to stay healthy? -the answers can be found in the di- etary guidelines for americans 2005. these guidelines provide science-based ad- vice to promote health and to reduce risk of chronic diseases through diet and physical activity.2 table 2-1 presents the nine dietary guidelines topics with their key recommendations. -these key recommendations, along with additional rec- ommendations for specific population groups, also appear throughout the text as their subjects are discussed. -the first three topics focus on choosing nutrient- dense foods within energy needs, maintaining a healthy body weight, and en- gaging in regular physical activity. -the fourth topic, food groups to encourage, focuses on the selection of a variety of fruits and vegetables, whole grains, and milk. -the next four topics advise people to choose sensibly in their use of fats, carbohydrates, salt, and alcoholic beverages (for those who partake). -finally, consumers are reminded to keep foods safe. -together, the dietary guide- lines point the way toward better health. -table 2-2 presents canada s guidelines for healthy eating. -some people might wonder why dietary guidelines include recommendations for physical activity. -the simple answer is that most people who maintain a healthy body weight do more than eat right. -they also exercise the equivalent of 60 min- utes or more of moderately intense physical activity daily. -as you will see repeat- edly throughout this text, food and physical activity choices are integral partners in supporting good health. -planning a healthy diet 39 moderation contributes to adequacy, balance, and kcalorie control. -empty-kcalorie foods: a popular term used to denote foods that contribute energy but lack protein, vitamins, and minerals. -moderation (dietary): providing enough but not too much of a substance. -variety (dietary): eating a wide selection of foods within and among the major food groups. -40 chapter 2 table 2-2 for healthy eating canada s guidelines enjoy a variety of foods. -emphasize cereals, breads, other grain products, vegetables, and fruits. -choose lower-fat dairy products, leaner meats, and foods prepared with little or no fat. -achieve and maintain a healthy body weight by enjoying regular physical activity and healthy eat- ing. -limit salt, alcohol, and caffeine. -source: these guidelines derive from action towards healthy eating canada s guidelines for healthy eating and recommended strategies for implementation. -table 2-1 for americans 2005 key recommendations of the dietary guidelines adequate nutrients within energy needs consume a variety of nutrient-dense foods and beverages within and among the basic food groups; limit intakes of saturated and trans fats, cholesterol, added sugars, salt, and alcohol. -meet recommended intakes within energy needs by adopting a balanced eating pattern, such as the usda food guide (see pp. -41 47). -weight management to maintain body weight in a healthy range, balance kcalories from foods and beverages with kcalories expended (see chapters 8 and 9). -to prevent gradual weight gain over time, make small decreases in food and beverage kcalories and increase physical activity. -physical activity engage in regular physical activity and reduce sedentary activities to promote health, psycho- logical well-being, and a healthy body weight. -achieve physical fitness by including cardiovascular conditioning, stretching exercises for flexi- bility, and resistance exercises or calisthenics for muscle strength and endurance. -food groups to encourage consume a sufficient amount of fruits, vegetables, milk and milk products, and whole grains while staying within energy needs. -select a variety of fruits and vegetables each day, including selections from all five vegetable subgroups (dark green, orange, legumes, starchy vegetables, and other vegetables) several times a week. -make at least half of the grain selections whole grains. -select fat-free or low-fat milk products. -fats consume less than 10 percent of kcalories from saturated fats and less than 300 milligrams of cholesterol per day, and keep trans fats consumption as low as possible (see chapter 5). -keep total fat intake between 20 and 35 percent of kcalories; choose from mostly polyunsatu- rated and monounsaturated fat sources such as fish, nuts, and vegetable oils. -select and prepare foods that are lean, low fat, or fat-free and low in saturated and/or trans fats. -carbohydrates choose fiber-rich fruits, vegetables, and whole grains often. -choose and prepare foods and beverages with little added sugars (see chapter 4). -reduce the incidence of dental caries by practicing good oral hygiene and consuming sugar- and starch-containing foods and beverages less frequently. -sodium and potassium choose and prepare foods with little salt (less than 2300 milligrams sodium or approximately 1 teaspoon salt daily). -at the same time, consume potassium-rich foods, such as fruits and veg- etables (see chapter 12). -alcoholic beverages those who choose to drink alcoholic beverages should do so sensibly and in moderation (up to one drink per day for women and up to two drinks per day for men). -some individuals should not consume alcoholic beverages (see highlight 7). -food safety to avoid microbial foodborne illness, keep foods safe: clean hands, food contact surfaces, and fruits and vegetables; separate raw, cooked, and ready-to-eat foods; cook foods to a safe inter- nal temperature; chill perishable food promptly; and defrost food properly. -avoid unpasteurized milk and products made from it; raw or undercooked eggs, meat, poultry, fish, and shellfish; unpasteurized juices; raw sprouts. -note: these guidelines are intended for adults and healthy children ages 2 and older. -source: the dietary guidelines for americans 2005, available at www.healthierus.gov/dietaryguidelines. -planning a healthy diet 41 in summary a well-planned diet delivers adequate nutrients, a balanced array of nutri- ents, and an appropriate amount of energy. -it is based on nutrient-dense foods, moderate in substances that can be detrimental to health, and varied in its selections. -the 2005 dietary guidelines apply these principles, offering practical advice on how to eat for good health. -diet-planning guides to plan a diet that achieves all of the dietary ideals just outlined, a person needs tools as well as knowledge. -among the most widely used tools for diet planning are food group plans that build a diet from clusters of foods that are similar in nutri- ent content. -thus each group represents a set of nutrients that differs somewhat from the nutrients supplied by the other groups. -selecting foods from each of the groups eases the task of creating an adequate and balanced diet. -usda food guide the 2005 dietary guidelines encourage consumers to adopt a balanced eating plan, such as the usda s food guide (see figure 2-1 on pp. -42 43). -the usda food guide assigns foods to five major groups and recommends daily amounts of foods from each group to meet nutrient needs. -in addition to presenting the food groups, the figure lists the most notable nutrients of each group, the serving equiv- alents, and the foods within each group sorted by nutrient density. -chapter 16 provides a food guide for young children, and appendix i presents canada s food group plan, the food guide to healthy eating. -five food groups: fruits vegetables grains meat and legumes milk dietary guidelines for americans 2005 meet recommended intakes within energy needs by adopting a balanced eating pattern, such as the usda food guide or the dash eating plan. -(the dash eating plan is presented in chapter 12.) -chapter 8 explains how to determine energy needs. -for an approximation, turn to the dri estimated energy requirement (eer) on the inside front cover. -recommended amounts all food groups offer valuable nutrients, and people should make selections from each group daily. -table 2-3 specifies the amounts of foods from each group needed daily to create a healthful diet for several energy (kcalorie) levels. -estimated daily kcalorie needs for sedentary and active men and food group plans: diet-planning tools that sort foods into groups based on nutrient content and then specify that people should eat certain amounts of foods from each group. -table 2-3 recommended daily amounts from each food group 1600 kcal 1800 kcal 2000 kcal 2200 kcal 2400 kcal 2600 kcal 2800 kcal 3000 kcal fruits vegetables grains meat and legumes milk oils 11 2 c 2 c 5 oz 5 oz 3 c 5 tsp 11 2 c 21 2 c 6 oz 5 oz 3 c 5 tsp 2 c 21 2 c 6 oz 51 2 oz 3 c 6 tsp 2 c 3 c 7 oz 6 oz 3 c 6 tsp 2 c 3 c 8 oz 61 2 oz 3 c 7 tsp 2 c 31 2 c 9 oz 61 2 oz 3 c 8 tsp 21 2 c 31 2 c 10 oz 7 oz 3 c 8 tsp discretionary 132 kcal 195 kcal 267 kcal 290 kcal 362 kcal 410 kcal 426 kcal 21 2 c 4 c 10 oz 7 oz 3 c 10 tsp 512 kcal kcalorie allowance 42 chapter 2 figure 2-1 usda food guide, 2005 key: foods generally high in nutrient density (choose most often) foods lower in nutrient density (limit selections) fruits vegetables grains consume a variety of fruits and no more than one-third of the recommended intake as fruit juice. -these foods contribute folate, vitamin a, vitamin c, potassium, and fiber. -1 2 c fruit is equivalent to 1 2 c fresh, frozen, or canned fruit; 1 small fruit; 1 4 c dried fruit; 1 2 c fruit juice. -apples, apricots, avocados, bananas, blueberries, cantaloupe, cherries, grapefruit, grapes, guava, kiwi, mango, oranges, papaya, peaches, pears, pineapples, plums, raspberries, strawberries, watermelon; dried fruit (dates, figs, raisins); unsweetened juices. -polara studios, inc. canned or frozen fruit in syrup; juices, punches, ades, and fruit drinks with added sugars; fried plantains. -polara studios, inc. choose a variety of vegetables from all five subgroups several times a week. -these foods contribute folate, vitamin a, vitamin c, vitamin k, vitamin e, magnesium, potassium, and fiber. -1 2 c vegetables is equivalent to 1 2 c cut-up raw or cooked vegetables; 1 2 c cooked legumes; 1 2 c vegetable juice; 1 c raw, leafy greens. -dark green vegetables: broccoli and leafy greens such as arugula, beet greens, bok choy, collard greens, kale, mustard greens, romaine lettuce, spinach, and turnip greens. -orange and deep yellow vegetables: carrots, carrot juice, pumpkin, sweet potatoes, and winter squash (acorn, butternut). -legumes: black beans, black-eyed peas, garbanzo beans (chickpeas), kidney beans, lentils, navy beans, pinto beans, soybeans and soy products such as tofu, and split peas. -starchy vegetables: cassava, corn, green peas, hominy, lima beans, and potatoes. -other vegetables: artichokes, asparagus, bamboo shoots, bean sprouts, beets, brussels sprouts, cabbages, cactus, cauliflower, celery, cucumbers, eggplant, green beans, iceberg lettuce, mushrooms, okra, onions, peppers, seaweed, snow peas, tomatoes, vegetable juices, zucchini. -baked beans, candied sweet potatoes, coleslaw, french fries, potato salad, refried beans, scalloped potatoes, tempura vegetables. -make at least half of the grain selections whole grains. -these foods contribute folate, niacin, riboflavin, thiamin, iron, magnesium, selenium, and fiber. -1 oz grains is equivalent to 1 slice bread; 1 2 c cooked rice, pasta, or cereal; 1 oz dry pasta or rice; 1 c ready-to-eat cereal; 3 c popped popcorn. -whole grains (amaranth, barley, brown rice, buckwheat, bulgur, millet, oats, quinoa, rye, wheat) and whole-grain, low-fat breads, cereals, crackers, and pastas; popcorn. -enriched bagels, breads, cereals, pastas (couscous, macaroni, spaghetti), pretzels, rice, rolls, tortillas. -polara studios, inc. biscuits, cakes, cookies, cornbread, crackers, croissants, doughnuts, french toast, fried rice, granola, muffins, pancakes, pastries, pies, presweetened cereals, taco shells, waffles. -figure 2-1 usda food guide, 2005, continued planning a healthy diet 43 meat, poultry, fish, legumes, eggs, and nuts make lean or low-fat choices. -prepare them with little, or no, added fat. -meat, poultry, fish, and eggs contribute protein, niacin, thiamin, vitamin b6, vitamin b12, iron, magnesium, potassium, and zinc; legumes and nuts are notable for their protein, folate, thiamin, vitamin e, iron, magnesium, potassium, zinc, and fiber. -1 oz meat is equivalent to 1 oz cooked lean meat, poultry, or fish; 1 egg; 1 4 c cooked legumes or tofu; 1 tbs peanut butter; 1 2 oz nuts or seeds. -poultry (no skin), fish, shellfish, legumes, eggs, lean meat (fat-trimmed beef, game, ham, lamb, pork); low-fat tofu, tempeh, peanut butter, nuts (almonds, filberts, peanuts, pistachios, walnuts) or seeds (flaxseeds, pumpkin seeds, sunflower seeds). -polara studios, inc. bacon; baked beans; fried meat, fish, poultry, eggs, or tofu; refried beans; ground beef; hot dogs; luncheon meats; marbled steaks; poultry with skin; sausages; spare ribs. -milk, yogurt, and cheese make fat-free or low-fat choices. -choose lactose-free products or other calcium-rich foods if you don't consume milk. -these foods contribute protein, riboflavin, vitamin b12, calcium, magnesium, potassium, and, when fortified, vitamin a and vitamin d. 1 c milk is equivalent to 1 c fat-free milk or yogurt; 11 2 oz fat-free natural cheese; 2 oz fat-free processed cheese. -fat-free milk and fat-free milk products such as buttermilk, cheeses, cottage cheese, yogurt; fat-free fortified soy milk. -oils polara studios, inc. 1% low-fat milk, 2% reduced-fat milk, and whole milk; low-fat, reduced-fat, and whole-milk products such as cheeses, cottage cheese, and yogurt; milk products with added sugars such as chocolate milk, custard, ice cream, ice milk, milk shakes, pudding, sherbet; fortified soy milk. -select the recommended amounts of oils from among these sources. -these foods contribute vitamin e and essential fatty acids (see chapter 5), along with abundant kcalories. -1 tsp oil is equivalent to 1 tbs low-fat mayonnaise; 2 tbs light salad dressing; 1 tsp vegetable oil; 1 tsp soft margarine. -liquid vegetable oils such as canola, corn, flaxseed, nut, olive, peanut, safflower, sesame, soybean, and sunflower oils; mayonnaise, oil-based salad dressing, soft trans-free margarine. -unsaturated oils that occur naturally in foods such as avocados, fatty fish, nuts, olives, seeds (flaxseeds, sesame seeds), and shellfish. -matthew farruggio solid fats and added sugars limit intakes of food and beverages with solid fats and added sugars. -solid fats deliver saturated fat and trans fat, and intake should be kept low. -solid fats and added sugars contribute abundant kcalories but few nutrients, and intakes should not exceed the discretionary kcalorie allowance kcalories to meet energy needs after all nutrient needs have been met with nutrient-dense foods. -alcohol also contributes abundant kcalories but few nutrients, and its kcalories are counted among discretionary kcalories. -see table 2-3 for some discretionary kcalorie allowances. -solid fats that occur in foods naturally such as milk fat and meat fat (see in previous lists). -solid fats that are often added to foods such as butter, cream cheese, hard margarine, lard, sour cream, and shortening. -matthew farruggio added sugars such as brown sugar, candy, honey, jelly, molasses, soft drinks, sugar, and syrup. -alcoholic beverages include beer, wine, and liquor. -44 chapter 2 table 2-4 kcalorie needs for adults estimated daily women 19 30 yr 31 50 yr 51+ yr men 19 30 yr 31 50 yr 51+ yr sedentarya activeb 2000 1800 1600 2400 2200 2000 2400 2200 2100 3000 2900 2600 asedentary describes a lifestyle that includes only the activities typical of day-to-day life. -bactive describes a lifestyle that includes physical activity equivalent to walking more than 3 miles per day at a rate of 3 to 4 miles per hour, in addition to the activities typical of day-to-day life. -kcalorie values for active people reflect the midpoint of the range appropriate for age and gender, but within each group, older adults may need fewer kcalories and younger adults may need more. -note: in addition to gender, age, and activity level, energy needs vary with height and weight (see chapter 8 and appendix f). -reminder: phytochemicals are the nonnutri- ent compounds found in plant-derived foods that have biological activity in the body. -the usda nutrients of concern are fiber, vi- tamin a, vitamin c, vitamin e, and the min- erals calcium, magnesium, and potassium. -legumes (lay-gyooms, leg-yooms): plants of the bean and pea family, with seeds that are rich in protein compared with other plant-derived foods. -women are shown in table 2-4. a sedentary young women needing 2000 kcalories a day, for example, would select 2 cups of fruit; 21/2 cups of vegetables (dispersed among the vegetable subgroups); 6 ounces of grain foods (with at least half coming from whole grains); 51/2 ounces of meat, poultry, or fish, or the equivalent of legumes, eggs, seeds, or nuts; and 3 cups of milk or yogurt, or the equivalent amount of cheese or fortified soy products. -additionally, a small amount of unsatu- rated oil, such as vegetable oil, or the oils of nuts, olives, or fatty fish, is required to supply needed nutrients. -all vegetables provide an array of vitamins, fiber, and the mineral potassium, but some vegetables are especially good sources of certain nutrients and beneficial phytochemicals. -for this reason, the usda food guide sorts the vegetable group into five subgroups. -the dark green vegetables deliver the b vitamin folate; the or- ange vegetables provide vitamin a; legumes supply iron and protein; the starchy vegetables contribute carbohydrate energy; and the other vegetables fill in the gaps and add more of these same nutrients. -in a 2000-kcalorie diet, then, the recommended 21/2 cups of daily vegetables should be varied among the subgroups over a week s time, as shown in table 2-5. in other words, consuming 21/2 cups of potatoes or even nutrient-rich spinach every day for seven days does not meet the recommended vegetable intakes. -potatoes and spinach make excellent choices when consumed in balance with vegetables from other subgroups. -intakes of vegetables are appropriately averaged over a week s time it is not necessary to include every subgroup every day. -notable nutrients as figure 2-1 notes, each food group contributes key nutri- ents. -this feature provides flexibility in diet planning because a person can select any food from a food group and receive similar nutrients. -for example, a person can choose milk, cheese, or yogurt and receive the same key nutrients. -importantly, foods provide not only these key nutrients, but small amounts of other nutrients and phytochemicals as well. -because legumes contribute the same key nutrients notably, protein, iron, and zinc as meats, poultry, and fish, they are included in the same food group. -for this reason, legumes are useful as meat alternatives, and they are also excellent sources of fiber and the b vitamin folate. -to encourage frequent consumption, the usda food guide also includes legumes as a subgroup of the vegetable group. -thus legumes count in either the vegetable group or the meat and legume group. -in gen- eral, people who regularly eat meat, poultry, and fish count legumes as a veg- etable, and vegetarians and others who seldom eat meat, poultry, or fish count legumes in the meat and legumes group. -the usda food guide encourages greater consumption from certain food groups to provide the nutrients most often lacking in the diets of americans. -in general, most people need to eat: more dark green vegetables, orange vegetables, legumes, fruits, whole grains, and low-fat milk and milk products table 2-5 recommended weekly amounts from the vegetable subgroups table 2-3 specifies the recommended amounts of total vegetables per day. -this table shows those amounts dispersed among five vegetable subgroups per week. -vegetable subgroups dark green orange and deep yellow legumes starchy other 1600 kcal 2 c 11 2 c 21 2 c 21 2 c 51 2 c 1800 kcal 3 c 2 c 3 c 3 c 2000 kcal 3 c 2 c 3 c 3 c 61 2 c 61 2 c 2200 kcal 2400 kcal 3 c 2 c 3 c 6 c 7 c 3 c 2 c 3 c 6 c 7 c 2600 kcal 3 c 21 2 c 31 2 c 7 c 81 2 c 2800 kcal 3 c 21 2 c 31 2 c 7 c 81 2 c 3000 kcal 3 c 21 2 c 31 2 c 9 c 10 c less refined grains, total fats (especially saturated fat, trans fat, and choles- terol), added sugars, and total kcalories nutrient density the usda food guide provides a foundation for a healthy diet by emphasizing nutrient-dense options within each food group. -by consistently se- lecting nutrient-dense foods, a person can obtain all the nutrients needed and still keep kcalories under control. -in contrast, eating foods that are low in nutrient den- sity makes it difficult to get enough nutrients without exceeding energy needs and gaining weight. -for this reason, consumers should select low-fat foods from each group and foods without added fats or sugars for example, fat-free milk instead of whole milk, baked chicken without the skin instead of hot dogs, green beans instead of french fries, orange juice instead of fruit punch, and whole-wheat bread instead of biscuits. -notice that the key in figure 2-1 indicates which foods within each group are high or low in nutrient density. -oil is a notable exception: even though oil is pure fat and therefore rich in kcalories, a small amount of oil from sources such as nuts, fish, or vegetable oils is necessary every day to provide nutrients lacking from other foods. -consequently these high-fat foods are listed among the nutrient-dense foods (see highlight 5 to learn why). -dietary guidelines for americans 2005 consume a variety of nutrient-dense foods and beverages within and among the basic food groups while choosing foods that limit the intake of saturated and trans fats, cholesterol, added sugars, salt, and alcohol. -discretionary kcalorie allowance at each kcalorie level, people who consis- tently choose nutrient-dense foods may be able to meet their nutrient needs without consuming their full allowance of kcalories. -the difference between the kcalories needed to supply nutrients and those needed for energy known as the discre- tionary kcalorie allowance is illustrated in figure 2-2. table 2-3 (p. 41) includes the discretionary kcalorie allowance for several kcalorie levels. -a person with dis- cretionary kcalories available might choose to: eat additional nutrient-dense foods, such as an extra serving of skinless chicken or a second ear of corn. -select a few foods with fats or added sugars, such as reduced-fat milk or sweetened cereal. -add a little fat or sugar to foods, such as butter or jelly on toast. -consume some alcohol. -(highlight 7 explains why this may not be a good choice for some individuals.) -alternatively, a person wanting to lose weight might choose to: not use the kcalories available from the discretionary kcalorie allowance. -added fats and sugars are always counted as discretionary kcalories. -the kcalo- ries from the fat in higher-fat milks and meats are also counted among discre- tionary kcalories. -it helps to think of fat-free milk as milk and whole milk or reduced-fat milk as milk with added fat. -similarly, meats should be the leanest; other cuts are meats with added fat. -puddings and other desserts made from whole milk provide discretionary kcalories from both the sugar added to sweeten them and the naturally occurring fat in the whole milk they contain. -even fruits, vegetables, and grains can carry discretionary kcalories into the diet in the form of peaches canned in syrup, scalloped potatoes, or high-fat crackers. -discretionary kcalories must be counted separately from the kcalories of the nu- trient-dense foods of which they may be a part. -a fried chicken leg, for example, provides discretionary kcalories from two sources: the naturally occurring fat of the chicken skin and the added fat absorbed during frying. -the kcalories of the skinless chicken underneath are not discretionary kcalories they are necessary to provide the nutrients of chicken. -planning a healthy diet 45 figure 2-2 discretionary kcalorie allowance for a 2000-kcalorie diet plan energy allowance to maintain weight 267 1733 discretionary kcalorie allowance energy intake to meet nutrient needs s e i r o a c k l 2000 1500 1000 500 0 discretionary kcalorie allowance: the kcalories remaining in a person s energy allowance after consuming enough nutrient- dense foods to meet all nutrient needs for a day. -46 chapter 2 for quick and easy estimates, visualize each portion as being about the size of a common object: 1 c fruit or vegetables = a baseball 1/4 c dried fruit = a golf ball 3 oz meat = a deck of cards 2 tbs peanut butter = a marshmallow 11/2 oz cheese = 6 stacked dice 1/2 c ice cream = a racquetball 4 small cookies = 4 poker chips serving equivalents recommended serving amounts for fruits, vegetables, and milk are measured in cups and those for grains and meats, in ounces. -figure 2-1 pro- vides equivalent measures among the foods in each group specifying, for example, that 1 ounce of grains is equivalent to 1 slice of bread or 1/2 cup of cooked rice. -a person using the usda food guide can become more familiar with measured portions by determining the answers to questions such as these: what portion of a cup is a small handful of raisins? -is a helping of mashed potatoes more or less than a half-cup? -how many ounces of cereal do you typically pour into the bowl? -how many ounces is the steak at your favorite restaurant? -how many cups of milk does your glass hold? -figure 2-1 (pp. -42 43) includes the serving sizes and equivalent amounts for foods within each group. -mixtures of foods some foods such as casseroles, soups, and sandwiches fall into two or more food groups. -with a little practice, users can learn to see these mix- tures of foods as items from various food groups. -for example, from the usda food guide point of view, a taco represents four different food groups: the taco shell from the grains group; the onions, lettuce, and tomatoes from the other vegetables group; the ground beef from the meat group; and the cheese from the milk group. -vegetarian food guide vegetarian diets rely mainly on plant foods: grains, vegetables, legumes, fruits, seeds, and nuts. -some vegetarian diets include eggs, milk products, or both. -people who do not eat meats or milk products can still use the usda food guide to create an adequate diet.3 the food groups are similar, and the amounts for each serving remain the same. -highlight 2 defines vegetarian terms and provides details on planning healthy vegetarian diets. -ethnic food choices people can use the usda food guide and still enjoy a di- verse array of culinary styles by sorting ethnic foods into their appropriate food groups. -for example, a person eating mexican foods would find tortillas in the grains group, jicama in the vegetable group, and guava in the fruit group. -table 2-6 features ethnic food choices. -table 2-6 ethnic food choices asian grains vegetables fruits meats and legumes milk mediterranean mexican s i b r o c / r e n y a t s - t r a g i u l y k c e b s e g a m i y t t e g / c s i d o t o h p s e g a m i y t t e g / c s i d o t o h p rice, noodles, millet amaranth, baby corn, bamboo shoots, chayote, bok choy, mung bean sprouts, sugar peas, straw mushrooms, water chestnuts, kelp pita pocket bread, pastas, rice, couscous, polenta, bulgur, focaccia, italian bread eggplant, tomatoes, peppers, cucumbers, grape leaves tortillas (corn or flour), taco shells, rice chayote, corn, jicama, tomato salsa, cactus, cassava, tomatoes, yams, chilies carambola, guava, kumquat, lychee, persimmon, melons, mandarin orange olives, grapes, figs guava, mango, papaya, avocado, plantain, bananas, oranges soybeans and soy products such as soy milk and tofu, squid, duck eggs, pork, poultry, fish and other seafood, peanuts, cashews fish and other seafood, gyros, lamb, chicken, beef, pork, sausage, lentils, fava beans refried beans, fish, chicken, chorizo, beef, eggs usually excluded ricotta, provolone, parmesan, feta, mozzarella, and goat cheeses; yogurt cheese, custard mypyramid steps to a healthier you the usda created an educational tool called mypyramid to illustrate the concepts of the dietary guidelines and the usda food guide. -figure 2-3 presents a graphic image of mypyramid, which was de- signed to encourage consumers to make healthy food and physical activity choices every day. -the abundant materials that support mypyramid help consumers choose the kinds and amounts of foods to eat each day (mypyramid.gov). -in addition to cre- ating a personal plan, consumers can find tips to help them improve their diet and lifestyle by taking small steps each day. -exchange lists food group plans are particularly well suited to help a person achieve dietary ade- quacy, balance, and variety. -exchange lists provide additional help in achieving kcalorie control and moderation. -originally developed for people with diabetes, ex- change systems have proved useful for general diet planning as well. -unlike the usda food guide, which sorts foods primarily by their vitamin and mineral contents, the exchange system sorts foods according to their energy-nutri- ent contents. -consequently, foods do not always appear on the exchange list where you might first expect to find them. -for example, cheeses are grouped with meats because, like meats, cheeses contribute energy from protein and fat but provide negligible carbohydrate. -(in the usda food guide presented earlier, cheeses are grouped with milk because they are milk products with similar calcium contents.) -figure 2-3 mypyramid: steps to a healthier you planning a healthy diet 47 mypyramid.gov offers information on vegetarian diets in its tips & resources section. -exchange lists: diet-planning tools that organize foods by their proportions of carbohydrate, fat, and protein. -foods on any single list can be used interchangeably. -the multiple colors of the pyramid illustrate variety: each color represents one of the five food groups, plus one for oils. -different widths of colors suggest the proportional contribution of each food group to a healthy diet. -the name, slogan, and website present a personalized approach. -a person climbing steps reminds consumers to be physically active each day. -greater intakes of grains, vegetables, fruits, and milk are encouraged by the width of orange, green, red, and blue, respectively. -the narrow slivers of color at the top imply moderation in foods rich in solid fats and added sugars. -the wide bottom represents nutrient-dense foods that should make up the bulk of the diet. -grains vegetables fruits oils milk meat & beans source: usda, 2005 48 chapter 2 for similar reasons, starchy vegetables such as corn, green peas, and potatoes are listed with grains on the starch list in the exchange system, rather than with the veg- etables. -likewise, olives are not classed as a fruit as a botanist would claim; they are classified as a fat because their fat content makes them more similar to oil than to berries. -bacon and nuts are also on the fat list to remind users of their high fat content. -these groupings highlight the characteristics of foods that are significant to energy in- take. -to learn more about this useful diet-planning tool, study appendix g, which gives details of the exchange system used in the united states, and appendix i, which provides details of beyond the basics, a similar diet-planning system used in canada. -putting the plan into action familiarizing yourself with each of the food groups is the first step in diet planning. -table 2-7 shows how to use the usda food guide to plan a 2000-kcalorie diet. -the amounts listed from each of the food groups (see the second column of the table) were taken from table 2-3 (p. 41). -the next step is to assign the food groups to meals (and snacks), as in the remaining columns of table 2-7. now, a person can begin to fill in the plan with real foods to create a menu. -for example, the breakfast calls for 1 ounce grain, 1/2 cup fruit, and 1 cup milk. -a per- son might select a bowl of cereal with banana slices and milk: o i g g u r r a f w e h t t a m most bagels today weigh in at 4 ounces or more meaning that a person eating one of these large bagels for breakfast is actually getting four or more grain servings, not one. -1 cup cereal = 1 ounce grain 1 small banana = 1/2 cup fruit 1 cup fat-free milk = 1 cup milk or 1/2 bagel and a bowl of cantaloupe pieces topped with yogurt: 1/2 small bagel = 1 ounce grain 1/2 cup melon pieces = 1/2 cup fruit 1 cup fat-free plain yogurt = 1 cup milk then the person can continue to create a diet plan by creating menus for lunch, din- ner, and snacks. -the final plan might look like the one in figure 2-4. with the addi- tion of a small amount of oils, this sample diet plan provides about 1850 kcalories and adequate amounts of the essential nutrients. -as you can see, we all make countless food-related decisions daily whether we have a plan or not. -following a plan, such as the usda food guide, that incorpo- rates health recommendations and diet-planning principles helps a person make wise decisions. -from guidelines to groceries dietary recommendations emphasize nutrient-rich foods such as whole grains, fruits, vegetables, lean meats, fish, poultry, and low-fat milk products. -you can de- sign such a diet for yourself, but how do you begin? -start with the foods you enjoy table 2-7 diet planning using the usda food guide this diet plan is one of many possibilities. -it follows the amounts of foods suggested for a 2000-kcalorie diet as shown in table 2-3 on p. 41 (with an extra 1 2 cup of vegetables). -food group fruits vegetables grains meat and legumes milk oils amounts breakfast lunch 2 c 21 2 c 6 oz 51 2 oz 3 c 51 2 tsp 1 2 c 1 oz 1 c 1 c 2 oz 2 oz 11 2 tsp snack 1 2 c 1 2 oz 1 c dinner snack 1 c 11 2 c 2 oz 31 2 oz 4 tsp 1 2 oz 1 c discretionary kcalorie allowance 267 kcal figure 2-4 a sample diet plan and menu this sample menu provides about 1850 kcalories and meets dietary recommendations to provide 45 to 65 percent of its kcalories from car- bohydrate, 20 to 35 percent from fat, and 10 to 35 percent from protein. -some discretionary kcalories were spent on the fat in the low-fat cheese and in the sugar added to the graham crackers; about 150 discretionary kcalories remain available in this 2000-kcalorie diet plan. -amounts energy (kcal) planning a healthy diet 49 breakfast 1 oz whole grains 1 c milk 1/2 c fruit 1 c whole-grain cereal 1 c fat-free milk 1 small banana (sliced) lunch 2 oz whole grains, 2 oz meats 11/2 tsp oils 1 c vegetables 1 turkey sandwich on roll 11/2 tbs low-fat mayonnaise 1 c vegetable juice snack 1/2 oz whole grains 4 whole-wheat, 1 c milk 1/2 c fruit reduced-fat crackers 11/2 oz low-fat cheddar cheese 1 small apple spaghetti with meat sauce 425 dinner 1 c salad 1/4 c garbanzo beans 2 tbs oil-based salad dressing and olives 1/2 c vegetables 1 oz meats 2 tsp oils 1/2 c vegetables, 21/2 oz meats, 2 oz enriched grains 1/2 c vegetables 2 tsp oils 1/2 c green beans 2 tsp soft margarine 1 c fruit 1 c strawberries snack 1/2 oz whole grains 1 c milk 3 graham crackers 1 c fat-free milk 108 83 105 272 75 53 86 74 72 8 71 81 22 67 49 90 83 . -c n i , s o i d u t s a r a l o p . -c n i , s o i d u t s a r a l o p . -c n i , s o i d u t s a r a l o p t s e u q t s e u q 50 chapter 2 processed foods: foods that have been treated to change their physical, chemical, microbiological, or sensory properties. -fortified: the addition to a food of nutrients that were either not originally present or present in insignificant amounts. -fortification can be used to correct or prevent a widespread nutrient deficiency or to balance the total nutrient profile of a food. -refined: the process by which the coarse parts of a food are removed. -when wheat is refined into flour, the bran, germ, and husk are removed, leaving only the endosperm. -enriched: the addition to a food of nutrients that were lost during processing so that the food will meet a specified standard. -whole grain: a grain milled in its entirety (all but the husk), not refined. -figure 2-5 a wheat plant eating. -then try to make improvements, little by little. -when shopping, think of the food groups, and choose nutrient-dense foods within each group. -be aware that many of the 50,000 food options available today are processed foods that have lost valuable nutrients and gained sugar, fat, and salt as they were transformed from farm-fresh foods to those found in the bags, boxes, and cans that line grocery-store shelves. -their value in the diet depends on the starting food and how it was prepared or processed. -sometimes these foods have been for- tified to improve their nutrient contents. -grains when shopping for grain products, you will find them described as refined, enriched, or whole grain. -these terms refer to the milling process and the making of grain products, and they have different nutrition implications (see figure 2-5). -re- fined foods may have lost many nutrients during processing; enriched products may have had some nutrients added back; and whole-grain products may be rich in fiber and all the nutrients found in the original grain. -as such, whole-grain prod- ucts support good health and should account for at least half of the grains daily. -when it became a common practice to refine the wheat flour used for bread by milling it and throwing away the bran and the germ, consumers suffered a tragic loss of many nutrients.4 as a consequence, in the early 1940s congress passed leg- islation requiring that all grain products that cross state lines be enriched with iron, the protective coating of bran around the kernel of grain is rich in nutrients and fiber. -the endosperm contains starch and proteins. -the germ is the seed that grows into a wheat plant, so it is especially rich in vitamins and minerals to support new life. -the outer husk (or chaff) is the inedible part of a grain. -whole-grain products contain much of the germ and bran, as well as the endosperm; that is why they are so nutritious. -common types of flour: (cid:129) refined flour finely ground endosperm that is usually enriched with nutrients and bleached for whiteness; sometimes called white flour. -(cid:129) wheat flour any flour made from the endosperm of the wheat kernel. -(cid:129) whole-wheat flour any flour made from the entire wheat kernel. -the difference between white flour and white wheat is noteworthy. -typically, white flour refers to refined flour (as defined above). -most flour whether refined, white, or whole wheat is made from red wheat. -whole-grain products made from red wheat are typically brown and full flavored. -to capture the health benefits of whole grains for consumers who prefer white bread, manufacturers have been experimenting with an albino variety of wheat called white wheat. -whole-grain products made from white wheat provide the nutrients and fiber of a whole grain with a light color and natural sweetness. -read labels carefully white bread is a whole-grain product only if it is made from whole white wheat. -refined grain products contain only the endosperm. -even with nutrients added back, they are not as nutritious as whole-grain products, as the next figure shows. -. -c n i c i h p a r g o t o h p t s e u q / n o s r e t e p m o t / m r a h s a m o h t planning a healthy diet 51 grain enrichment nutrients: iron thiamin riboflavin niacin folate dietary guidelines for americans 2005 consume 3 or more ounce-equivalents of whole-grain products per day, with the rest of the recommended grains coming from enriched or whole-grain products. -in general, at least half the grains should come from whole grains. -thiamin, riboflavin, and niacin. -in 1996, this legislation was amended to include folate, a vitamin considered essential in the prevention of some birth defects. -most grain products that have been refined, such as rice, wheat pastas like macaroni and spaghetti, and cereals (both cooked and ready-to-eat types), have subse- quently been enriched, and their labels say so. -enrichment doesn t make a slice of bread rich in these added nutrients, but peo- ple who eat several slices a day obtain significantly more of these nutrients than they would from unenriched bread. -even though the enrichment of flour helps to prevent deficiencies of these nutrients, it fails to compensate for losses of many other nutri- ents and fiber. -as figure 2-6 shows, whole-grain items still outshine the enriched ones. -only whole-grain flour contains all of the nutritive portions of the grain. -whole- grain products, such as brown rice or oatmeal, provide more nutrients and fiber and contain less salt and sugar than flavored, processed rice or sweetened cereals. -speaking of cereals, ready-to-eat breakfast cereals are the most highly fortified foods on the market. -like an enriched food, a fortified food has had nutrients added during processing, but in a fortified food, the added nutrients may not have been present in the original product. -(the terms fortified and enriched may be used inter- changeably.5) some breakfast cereals made from refined flour and fortified with high doses of vitamins and minerals are actually more like supplements disguised figure 2-6 nutrients in bread whole-grain bread is more nutritious than other breads, even enriched bread. -for iron, thiamin, riboflavin, niacin, and folate, enriched bread provides about the same quantities as whole-grain bread and significantly more than unenriched bread. -for fiber and the other nutrients (those shown here as well as those not shown), enriched bread provides less than whole-grain bread. -iron niacin thiamin riboflavin folate vitamin b6 magnesium zinc fiber 10 100 50 percentage of nutrients as compared with whole-grain bread 30 20 40 70 90 60 80 key: whole-grain bread enriched bread unenriched bread y h p a r g o t o h p g r e b g n e i r e g when shopping for bread, look for the descrip- tive words whole grain or whole wheat and check the fiber contents on the nutrition facts panel of the label the more fiber, the more likely the bread is a whole-grain product. -52 chapter 2 figure 2-7 eat 5 to 9 a day for better health the 5 to 9 a day campaign (www.5aday.gov) encourages consumers to eat a variety of fruits and vegetables. -because everyone benefits from eating more, the campaign s slogan and messages are being revised to say fruits and veggies more matters. -as cereals than they are like whole grains. -they may be nutritious with respect to the nutrients added but they still may fail to convey the full spectrum of nu- trients that a whole-grain food or a mixture of such foods might provide. -still, for- tified foods help people meet their vitamin and mineral needs.6 vegetables posters in the produce section of grocery stores encourage consumers to eat 5 a day. -such efforts are part of a national educational campaign to in- crease fruit and vegetable consumption to 5 to 9 servings every day (see figure 2-7). -to help consumers remember to eat a variety of fruits and vegetables, the campaign provides practical tips, such as selecting from each of five colors. -choose fresh vegetables often, especially dark green leafy and yellow-orange vegetables like spinach, broccoli, and sweet potatoes. -cooked or raw, vegetables are good sources of vitamins, minerals, and fiber. -frozen and canned vegetables with- out added salt are acceptable alternatives to fresh. -to control fat, energy, and sodium intakes, limit butter and salt on vegetables. -legumes include a variety of beans and peas: choose often from the variety of legumes available. -they are an economical, adzuki beans black beans black-eyed peas fava beans garbanzo beans great northern beans soybeans split peas kidney beans lentils lima beans navy beans peanuts pinto beans low-fat, nutrient- and fiber-rich food choice. -dietary guidelines for americans 2005 choose a variety of fruits and vegetables each day. -in particular, select from all five vegetable subgroups (dark green, orange, legumes, starchy vegetables, and other vegetables) several times a week. -fruit choose fresh fruits often, especially citrus fruits and yellow-orange fruits like cantaloupes and peaches. -frozen, dried, and canned fruits without added sugar are acceptable alternatives to fresh. -fruits supply valuable vitamins, minerals, fibers, and phytochemicals. -they add flavors, colors, and textures to meals, and their nat- ural sweetness makes them enjoyable as snacks or desserts. -. -c n i c s i d o t o h p 8 9 9 1 . -c n i c s i d o t o h p 8 9 9 1 t i d e o t o h p / n a m w e n z e n i t r a m a i c i l e f t i d e o t o h p / n a m w e n l e a h c i m combining legumes with foods from other food groups creates delicious meals. -add rice to red beans for a hearty meal. -enjoy a greek salad topped with garbanzo beans for a little ethnic diversity. -a bit of meat and lots of spices turn kidney beans into chili con carne. -fruit juices are healthy beverages but contain little dietary fiber compared with whole fruits. -whole fruits satisfy the appetite better than juices, thereby helping people to limit food energy intakes. -for people who need extra food energy, though, juices are a good choice. -be aware that sweetened fruit drinks or ades contain mostly water, sugar, and a little juice for flavor. -some may have been fortified with vitamin c or calcium but lack any other significant nutritional value. -dietary guidelines for americans 2005 consume a sufficient amount of fruits and vegetables while staying within energy needs. -meat, fish, and poultry meat, fish, and poultry provide essential minerals, such as iron and zinc, and abundant b vitamins as well as protein. -to buy and prepare these foods without excess energy, fat, and sodium takes a little knowledge and planning. -when shopping in the meat department, choose fish, poultry, and lean cuts of beef and pork named round or loin (as in top round or pork tenderloin). -as a guide, prime and choice cuts generally have more fat than select cuts. -restaurants usually serve prime cuts. -ground beef, even lean ground beef, derives most of its food energy from fat. -have the butcher trim and grind a lean round steak instead. -alternatively, textured vegetable protein can be used instead of ground beef in a casserole, spaghetti sauce, or chili, saving fat kcalories. -weigh meat after it is cooked and the bones and fat are removed. -in general, 4 ounces of raw meat is equal to about 3 ounces of cooked meat. -some examples of 3-ounce portions of meat include 1 medium pork chop, 1/2 chicken breast, or 1 steak or hamburger about the size of a deck of cards. -to keep fat intake moderate, bake, roast, broil, grill, or braise meats (but do not fry them in fat); remove the skin from poultry after cooking; trim visible fat before cooking; and drain fat after cooking. -chapter 5 offers many additional strategies for moderating fat intake. -milk shoppers find a variety of fortified foods in the dairy case. -examples are milk, to which vitamins a and d have been added, and soy milk, to which calcium, vitamin d, and vitamin b12 have been added. -in addition, shoppers may find imitation foods (such as cheese products), food substitutes (such as egg substitutes), and func- tional foods (such as margarine with added plant sterols). -as food technology ad- vances, many such foods offer alternatives to traditional choices that may help people who want to reduce their fat and cholesterol intakes. -chapter 5 gives other examples. -when shopping, choose fat-free or low-fat milk, yogurt, and cheeses. -such se- lections help consumers meet their vitamin and mineral needs within their energy and fat allowances.7 milk products are important sources of calcium, but can pro- vide too much sodium and fat if not selected with care. -dietary guidelines for americans 2005 consume 3 cups per day of fat-free or low-fat milk or equivalent milk products. -in summary food group plans such as the usda food guide help consumers select the types and amounts of foods to provide adequacy, balance, and variety in the diet. -they make it easier to plan a diet that includes a balance of grains, vegetables, fruits, meats, and milk products. -in making any food choice, remember to view the food in the context of your total diet. -the combination of many different foods provides the abundance of nutrients that is so essential to a healthy diet. -planning a healthy diet 53 be aware that not all soy milks have been fortified. -read labels carefully. -reminder: functional foods contain physiologically active compounds that pro- vide health benefits beyond basic nutrition. -milk descriptions: fat-free milk may also be called non- fat, skim, zero-fat, or no-fat. -low-fat milk refers to 1% milk. -reduced-fat milk refers to 2% milk; it may also be called less-fat. -textured vegetable protein: processed soybean protein used in vegetarian products such as soy burgers. -imitation foods: foods that substitute for and resemble another food, but are nutritionally inferior to it with respect to vitamin, mineral, or protein content. -if the substitute is not inferior to the food it resembles and if its name provides an accurate description of the product, it need not be labeled imitation. -food substitutes: foods that are designed to replace other foods. -54 chapter 2 figure 2-8 example of a food label food labels many consumers read food labels to help them make healthy choices.8 food la- bels appear on virtually all processed foods, and posters or brochures provide similar nutrition information for fresh meats, fruits, and vegetables (see figure 2-8). -a few foods need not carry nutrition labels: those contributing few nutri- ents, such as plain coffee, tea, and spices; those produced by small businesses; and those prepared and sold in the same establishment. -producers of some of these items, however, voluntarily use labels. -even markets selling nonpackaged items voluntarily present nutrient information, either in brochures or on signs posted at the point of purchase. -restaurants need not supply complete nutri- tion information for menu items unless claims such as low fat or heart healthy have been made. -when ordering such items, keep in mind that restaurants tend to serve extra-large portions two to three times standard serving sizes. -a low-fat ice cream, for example, may have only 3 grams of fat per 1/2 cup, but you may be served 2 cups for a total of 12 grams of fat and all their accompanying kcalories. -w e sto n m ills, m a ple w o o d illin ois 0 0 5 5 0 the name and address of the manufacturer, packer, or distributor the common or usual product name approved nutrient claims if the product meets specified criteria no saturated fat, no trans fat and no cholesterol the net contents in weight, measure, or count approved health claims stated in terms of the total diet although many factors affect heart disease, diets low in saturated fat and cholesterol may reduce the risk of this disease. -nutrition facts serving size 3/4 cup (28 g) servings per container 14 calories from fat 9 amount per serving % daily value* 2% calories 110 0% 0% total fat 1 g saturated fat 0 g 10% cholesterol 0 mg 8% 6% sodium 250 mg total carbohydrate 23 g dietary fiber 1.5 g sugars 10 g vitamin a 25% (cid:129) vitamin c 25% (cid:129) calcium 2% (cid:129) iron 25% protein 3 g *percent daily values are based on a 2000 calorie diet. -your daily values may be higher or lower depending on your calorie needs. -calories: less than less than less than total fat less than sat fat cholesterol total carbohydrate sodium fat 9 (cid:129) carbohydrate 4 (cid:129) protein 4 fiber calories per gram ingredients, listed in descending order of predominance: corn, sugar, salt, malt flavoring, freshness preserved by bht. -vitamins and minerals: vitamin c (sodium ascorbate), niachamide, iron, vitamin b6 (pyridoxine hydrochloride), vitamin b2 (riboflavin), vitamin a (palmitate), vitamin b1 (thiamin hydrochloride), folic acid, and vitamin d. 2500 80 g 25 g 300 mg 2400 mg 375 g 30 g 2000 65 g 20 g 300 mg 2400 mg 300 g 25 g nutrition facts 3/4 cup (28 g) serving size servings per container 14 amount per serving calories 110 calories from fat 9 % daily value* total fat 1 g saturated fat 0 g trans fat 0 g cholesterol 0 mg sodium 250 mg total carbohydrate 23 g dietary fiber 1.5 g sugars 10 g protein 3 g 2% 0% 0% 10% 8% 6% vitamin a 25% (cid:129) vitamin c 25% (cid:129) calcium 2% (cid:129) iron 25% *percent daily values are based on a 2000 calorie diet. -your daily values may be higher or lower depending on your calorie needs. -total fat sat fat cholesterol sodium calories: less than less than less than less than total carbohydrate fiber 2000 65 g 20 g 300 mg 2400 mg 300 g 25 g 2500 80 g 25 g 300 mg 2400 mg 375 g 30 g calories per gram fat 9 (cid:129) carbohydrate 4 (cid:129) protein 4 ingredients, listed in descending order of predominance: corn, sugar, salt, malt flavoring, freshness preserved by bht. -vitamins and minerals: vitamin c (sodium ascorbate), niacinamide , iron, vitamin b6 (pyridoxine hydrochloride), vitamin b2 (riboflavin), vitamin a (palmitate), vitamin b1 (thiamin hydrochloride), folic acid, and vitamin d. the serving size and number of servings per container kcalorie information and quantities of nutrients per serving, in actual amounts quantities of nutrients as % daily values based on a 2000-kcalorie energy intake daily values reminder for selected nutrients for a 2000- and a 2500- kcalorie diet kcalorie per gram reminder the ingredients in descending order of predominance by weight the ingredient list all packaged foods must list all ingredients on the label in descending order of pre- dominance by weight. -knowing that the first ingredient predominates by weight, consumers can glean much information. -compare these products, for example: a beverage powder that contains sugar, citric acid, natural flavors . -. -. -ver- sus a juice that contains water, tomato concentrate, concentrated juices of carrots, celery . -. -. -a cereal that contains puffed milled corn, sugar, corn syrup, molasses, salt . -. -. -versus one that contains 100 percent rolled oats a canned fruit that contains sugar, apples, water versus one that contains simply apples, water in each of these comparisons, consumers can see that the second product is the more nutrient dense. -serving sizes because labels present nutrient information per serving, they must identify the size of the serving. -the food and drug administration (fda) has established specific serv- ing sizes for various foods and requires that all labels for a given product use the same serving size. -for example, the serving size for all ice creams is 1/2 cup and for all beverages, 8 fluid ounces. -this facilitates comparison shopping. -consumers can see at a glance which brand has more or fewer kcalories or grams of fat, for exam- ple. -standard serving sizes are expressed in both common household measures, such as cups, and metric measures, such as milliliters, to accommodate users of both types of measures (see table 2-8). -when examining the nutrition facts on a food label, consumers need to compare the serving size on the label with how much they actually eat and adjust their calcu- lations accordingly. -for example, if the serving size is four cookies and you only eat two, then you need to cut the nutrient and kcalorie values in half; similarly, if you eat eight cookies, then you need to double the values. -notice, too, that small bags or in- dividually wrapped items, such as chips or candy bars, may contain more than a sin- gle serving. -the number of servings per container is listed just below the serving size. -be aware that serving sizes on food labels are not always the same as those of the usda food guide.9 for example, a serving of rice on a food label is 1 cup, whereas in the usda food guide it is 1/2 cup. -unfortunately, this discrepancy, coupled with each person s own perception (oftentimes misperception) of standard serving sizes, some- times creates confusion for consumers trying to follow recommendations. -nutrition facts in addition to the serving size and the servings per container, the fda requires that the nutrition facts panel on food labels present nutrient information in two ways in quantities (such as grams) and as percentages of standards called the daily values. -the nutrition facts panel must provide the nutrient amount, per- cent daily value, or both for the following: total food energy (kcalories) food energy from fat (kcalories) total fat (grams and percent daily value) saturated fat (grams and percent daily value) trans fat (grams) cholesterol (milligrams and percent daily value) sodium (milligrams and percent daily value) planning a healthy diet 55 table 2-8 measures household and metric 1 teaspoon (tsp) (cid:2) 5 milliliters (ml) 1 tablespoon (tbs) (cid:2) 15 ml 1 cup (c) (cid:2) 240 ml 1 fluid ounce (fl oz) (cid:2) 30 ml 1 ounce (oz) (cid:2) 28 grams (g) note: the aids to calculation section at the back of the book provides additional weights and measures. -daily values (dv): reference values developed by the fda specifically for use on food labels. -56 chapter 2 t i d e o t o h p / a m o i e d . -m e t y a k consumers read food labels to learn about the nutrient contents of a food or to compare simi- lar foods. -total carbohydrate, which includes starch, sugar, and fiber (grams and per- cent daily value) dietary fiber (grams and percent daily value) sugars, which includes both those naturally present in and those added to the food (grams) protein (grams) the labels must also present nutrient content information as a percentage of the daily values for the following vitamins and minerals: vitamin a vitamin c iron calcium the daily values the fda developed the daily values for use on food labels because comparing nu- trient amounts against a standard helps make the numbers more meaningful to consumers. -table 2-9 presents the daily value standards for nutrients that are re- quired to provide this information. -food labels list the amount of a nutrient in a product as a percentage of its daily value. -a person reading a food label might won- der, for example, whether 1 milligram of iron or calcium is a little or a lot. -as table 2-9 shows, the daily value for iron is 18 milligrams, so 1 milligram of iron is enough to notice it is more than 5 percent, and that is what the food label will say. -but be- cause the daily value for calcium on food labels is 1000 milligrams, 1 milligram of calcium is insignificant, and the food label will read 0%. -the daily values reflect dietary recommendations for nutrients and dietary com- ponents that have important relationships with health. -the % daily value col- umn on a label provides a ballpark estimate of how individual foods contribute to the total diet. -it compares key nutrients in a serving of food with the goals of a per- son consuming 2000 kcalories per day. -a 2000-kcalorie diet is considered about right for sedentary younger women, active older women, and sedentary older men. -table 2-9 daily values for food labels food labels must present the % daily value for these nutrients. -food component fat saturated fat cholesterol carbohydrate (total) fiber protein sodium potassium vitamin c vitamin a calcium iron daily value 65 g 20 g 300 mg 300 g 25 g 50 g 2400 mg 3500 mg 60 mg 1500 g 1000 mg 18 mg calculation factors 30% of kcalories 10% of kcalories 60% of kcalories 11.5 g per 1000 kcalories 10% of kcalories note: daily values were established for adults and children over 4 years old. -the values for energy-yielding nutrients are based on 2000 kcalories a day. -for fiber, the daily value was rounded up from 23. planning a healthy diet 57 % daily values: (cid:3) 20% = high or excellent source 10-19% = good source (cid:4) 5% = low to calculate your personal daily values, log on to www.thomsonedu.com/thomsonnow, then go to chapter 2, then go to how to. -young children and sedentary older women may need fewer kcalories. -most labels list, at the bottom, daily values for both a 2000-kcalorie and a 2500-kcalorie diet, but the % daily value column on all labels applies only to a 2000-kcalorie diet. -a 2500-kcalorie diet is considered about right for many men, teenage boys, and active younger women. -people who are exceptionally active may have still higher energy needs. -labels may also provide a reminder of the kcalories in a gram of carbohy- drate, fat, and protein just below the daily value information (review figure 2-8). -people who consume 2000 kcalories a day can simply add up all of the % daily values for a particular nutrient to see if their diet for the day fits recommen- dations. -people who require more or less than 2000 kcalories daily must do some calculations to see how foods compare with their personal nutrition goals. -they can use the calculation column in table 2-9 or the suggestions presented in the ac- companying how to feature. -daily values help consumers see easily whether a food contributes a little or a lot of a nutrient. -for example, the % daily value column on a label of macaroni and cheese may say 20 percent for fat. -this tells the consumer that each serving of this food contains about 20 percent of the day s allotted 65 grams of fat. -a person consum- ing 2000 kcalories a day could simply keep track of the percentages of daily values from foods eaten in a day and try not to exceed 100 percent. -be aware that for some nutrients (such as fat and sodium) you will want to select foods with a low % daily value and for others (such as calcium and fiber) you will want a high % daily value. -to determine whether a particular food is a wise choice, a consumer needs to consider its place in the diet among all the other foods eaten during the day. -daily values also make it easy to compare foods. -for example, a consumer might discover that frozen macaroni and cheese has a daily value for fat of 20 per- cent, whereas macaroni and cheese prepared from a boxed mix has a daily value of 15 percent. -by comparing labels, consumers who are concerned about their fat intakes can make informed decisions. -the daily values used on labels are based in part on values from the 1968 rec- ommended dietary allowances. -since 1997, dietary reference intakes that reflect scientific research on diet and health have been released. -efforts to update the daily values based on these current recommendations and to make labels more effective and easier to understand are underway.10 how to calculate personal daily values the daily values on food labels are designed for a 2000-kcalorie intake, but you can calculate a personal set of daily values based on your energy allowance. -consider a 1500-kcalorie intake, for exam- ple. -to calculate a daily goal for fat, multi- ply energy intake by 30 percent: 1500 kcal (cid:5) 0.30 kcal from fat (cid:2) 450 kcal from fat the kcalories from fat are listed on food labels, so you can add all the kcalories from fat values for a day, using 450 as an upper limit. -a person who prefers to count grams of fat can divide this 450 kcalories from fat by 9 kcalories per gram to determine the goal in grams: 450 kcal from fat (cid:6) 9 kcal/g (cid:2) 50 g fat alternatively, a person can calculate that 1500 kcalories is 75 percent of the 2000-kcalorie intake used for daily values: 1500 kcal (cid:6) 2000 kcal (cid:2) 0.75 0.75 (cid:5) 100 (cid:2) 75% then, instead of trying to achieve 100 percent of the daily value, a person consuming 1500 kcalories will aim for 75 percent. -similarly, a person con- suming 2800 kcalories would aim for 140 percent: 2800 kcal (cid:6) 2000 kcal (cid:2) 1.40 or 140% table 2-9 includes a calculation column that can help you estimate your personal daily value for several nutrients. -58 chapter 2 nutrient claims: statements that characterize the quantity of a nutrient in a food. -nutrient claims have you noticed phrases such as good source of fiber on a box of cereal or rich in calcium on a package of cheese? -these and other nutrient claims may be used on labels as long as they meet fda definitions, which include the conditions under which each term can be used. -for example, in addition to having less than 2 milligrams of cholesterol, a cholesterol-free product may not contain more than 2 grams of saturated fat and trans fat combined per serving. -the accompa- nying glossary defines nutrient terms on food labels, including criteria for foods described as low, reduced, and free. -some descriptions imply that a food contains, or does not contain, a nutrient. -im- plied claims are prohibited unless they meet specified criteria. -for example, a claim that a product contains no oil implies that the food contains no fat. -if the product is truly fat-free, then it may make the no-oil claim, but if it contains another source of fat, such as butter, it may not. -g lossary of terms on food labels general terms low: an amount that would allow free: nutritionally trivial and unlikely to have a physiological consequence; synonyms include without, no, and zero. -a food that does not contain a nutrient naturally may make such a claim, but only as it applies to all similar foods (for example, applesauce, a fat-free food ). -good source of: the product provides between 10 and 19% of the daily value for a given nutrient per serving. -healthy: a food that is low in fat, saturated fat, cholesterol, and sodium and that contains at least 10% of the daily values for vitamin a, vitamin c, iron, calcium, protein, or fiber. -high: 20% or more of the daily value for a given nutrient per serving; synonyms include rich in or excellent source. -less: at least 25% less of a given nutrient or kcalories than the comparison food (see individual nutrients); synonyms include fewer and reduced. -light or lite: one-third fewer kcalories than the comparison food; 50% or less of the fat or sodium than the comparison food; any use of the term other than as defined must specify what it is referring to (for example, light in color or light in texture ). -frequent consumption of a food without exceeding the daily value for the nutrient. -a food that is naturally low in a nutrient may make such a claim, but only as it applies to all similar foods (for example, fresh cauliflower, a low- sodium food ); synonyms include little, few, and low source of. -more: at least 10% more of the daily value for a given nutrient than the comparison food; synonyms include added and extra. -organic: on food labels, that at least 95% of the product s ingredients have been grown and processsed according to usda regulations defining the use of fertilizers, herbicides, insecticides, fungicides, preservatives, and other chemical ingredients (see chapter 19). -energy kcalorie-free: fewer than 5 kcal per serving. -low kcalorie: 40 kcal or less per serving. -reduced kcalorie: at least 25% fewer kcalories per serving than the comparison food. -fat and cholesterola percent fat-free: may be used only if the product meets the definition of low fat or fat-free and must reflect the amount of fat in 100 g (for example, a food that contains 2.5 g of fat per 50 g can claim to be 95 percent fat free ). -fat-free: less than 0.5 g of fat per serving (and no added fat or oil); synonyms include zero- fat, no-fat, and nonfat. -low fat: 3 g or less fat per serving. -less fat: 25% or less fat than the comparison food. -saturated fat-free: less than 0.5 g of saturated fat and 0.5 g of trans fat per serving. -low saturated fat: 1 g or less saturated fat and less than 0.5 g of trans fat per serving. -less saturated fat: 25% or less saturated fat and trans fat combined than the comparison food. -trans fat-free: less than 0.5 g of trans fat and less than 0.5 g of saturated fat per serving. -cholesterol-free: less than 2 mg cholesterol per serving and 2 g or less saturated fat and trans fat combined per serving. -low cholesterol: 20 mg or less cholesterol per serving and 2 g or less saturated fat and trans fat combined per serving. -less cholesterol: 25% or less cholesterol than the comparison food (reflecting a reduction of at least 20 mg per serving), and 2 g or less saturated fat and trans fat combined per serving. -extra lean: less than 5 g of fat, 2 g of saturated fat and trans fat combined, and 95 mg of cholesterol per serving and per 100 g of meat, poultry, and seafood. -lean: less than 10 g of fat, 4.5 g of saturated fat and trans fat combined, and 95 mg of cholesterol per serving and per 100 g of meat, poultry, and seafood. -carbohydrates: fiber and sugar high fiber: 5 g or more fiber per serving. -a high-fiber claim made on a food that contains more than 3 g fat per serving and per 100 g of food must also declare total fat. -sugar-free: less than 0.5 g of sugar per serving. -sodium sodium-free and salt-free: less than 5 mg of sodium per serving. -low sodium: 140 mg or less per serving. -very low sodium: 35 mg or less per serving. -afoods containing more than 13 grams total fat per serving or per 50 grams of food must indicate those contents immediately after a cholesterol claim. -as you can see, all cholesterol claims are prohibited when the food contains more than 2 grams saturated fat and trans fat combined per serving. -health claims until 2003, the fda held manufacturers to the highest standards of scientific evi- dence before approving health claims on food labels. -consumers reading diets low in sodium may reduce the risk of high blood pressure, for example, knew that the fda had examined enough scientific evidence to establish a clear link be- tween diet and health. -such reliable health claims make up the fda s a list (see table 2-10). -the fda refers to these health claims as unqualified not that they lack the necessary qualifications, but that they can stand alone without further explanation or qualification. -these reliable health claims still appear on some food labels, but finding them may be difficult now that the fda has created three additional categories of claims based on scientific evidence that is less conclusive (see table 2-11). -these categories were added after a court ruled: holding only the highest scientific standard for claims interferes with commercial free speech. -food manufacturers had argued that they should be allowed to inform consumers about possible benefits based on less than clear and convincing evidence. -the fda must allow manufacturers to provide information about nutrients and foods that show preliminary promise in preventing disease. -these health claims are qualified not that they meet the necessary qualifications, but that they require a qualifying explanation. -for exam- ple, very limited and preliminary research suggests that eating one-half to one cup of tomatoes and/or tomato sauce a week may reduce the risk of prostate can- cer. -fda concludes that there is little scientific evidence supporting the claim. -con- sumer groups argue that such information is confusing. -even with required disclaimers for health claims graded b, c, or d, distinguishing a claims from others is difficult, as the next section shows. -(health claims on supplement la- bels are presented in highlight 10.) -structure-function claims unlike health claims, which require food manufacturers to collect scientific evidence and petition the fda, structure-function claims can be made without any fda approval. -product labels can claim to slow aging, improve memory, and build strong bones without any proof. -the only criterion for a structure-function claim is that it must not mention a disease or symptom. -unfortunately, structure-function claims can be deceptively similar to health claims. -consider these statements: may reduce the risk of heart disease. -promotes a healthy heart. -most consumers do not distinguish between these two types of claims.11 in the state- ments above, for example, the first is a health claim that requires fda approval and the second is an unproven, but legal, structure-function claim. -table 2-12 lists ex- amples of structure-function claims. -planning a healthy diet 59 table 2-10 claims the a list food label health calcium and reduced risk of osteoporosis sodium and reduced risk of hypertension dietary saturated fat and cholesterol and reduced risk of coronary heart disease dietary fat and reduced risk of cancer fiber-containing grain products, fruits, and vegetables and reduced risk of cancer fruits, vegetables, and grain products that contain fiber, particularly soluble fiber, and reduced risk of coronary heart disease fruits and vegetables and reduced risk of cancer folate and reduced risk of neural tube defects sugar alcohols and reduced risk of tooth decay soluble fiber from whole oats and from psyl- lium seed husk and reduced risk of heart disease soy protein and reduced risk of heart disease whole grains and reduced risk of heart disease and certain cancers plant sterol and plant stanol esters and heart disease potassium and reduced risk of hypertension and stroke health claims: statements that characterize the relationship between a nutrient or other substance in a food and a disease or health- related condition. -structure-function claims: statements that characterize the relationship between a nutrient or other substance in a food and its role in the body. -table 2-11 the fda s health claims report card grade level of confidence in health claim required label disclaimers a b c d high: significant scientific agreement moderate: evidence is supportive but not conclusive low: evidence is limited and not conclusive very low: little scientific evidence supporting this claim these health claims do not require disclaimers; see table 2-10 for examples. -[health claim.] -although there is scientific evidence supporting this claim, the evidence is not conclusive. -some scientific evidence suggests [health claim]. -however, fda has determined that this evidence is limited and not conclusive. -very limited and preliminary scientific research suggests [health claim]. -fda concludes that there is little scientific evidence supporting this claim. -60 chapter 2 table 2-12 examples of structure- function claims builds strong bones promotes relaxation improves memory boosts the immune system supports heart health defends your health slows aging guards against colds lifts your spirits note: structure-function claims cannot make statements about diseases. -see table 2-10 on p. 59 for examples of health claims. -consumer education because labels are valuable only if people know how to use them, the fda has de- signed several programs to educate consumers. -consumers who understand how to read labels are best able to apply the information to achieve and maintain health- ful dietary practices. -table 2-13 shows how the messages from the 2005 dietary guidelines, the usda food guide, and food labels coordinate with each other. -to promote healthy eating and physical activity, the healthier us initiative coordinates the efforts of national educational programs developed by government agencies.12 the mission of this ini- tiative is to deliver simple messages that will motivate consumers to make small changes in their eating and physical activity habits to yield big rewards. -table 2-13 from guidelines to groceries dietary guidelines usda food guide/mypyramid food labels adequate nutrients within energy needs select the recommended amounts from each food group at the energy level appropriate for your energy needs. -look for foods that describe their vitamin, mineral, or fiber contents as a good source or high. -weight management select nutrient-dense foods and beverages within and among the food groups. -look for foods that describe their kcalorie contents as free, low, reduced, light, or less. -physical activity limit high-fat foods and foods and beverages with added fats and sugars. -use appropriate portion sizes. -be phyisically active for at least 30 minutes most days of the week. -children and teenagers should be physically active for 60 minutes every day, or most days. -food groups to encourage select a variety of fruits each day. -look for foods that describe their fiber contents as good source or high. -include vegetables from all five subgroups (dark green, orange, legumes, starchy vegetables, and other vegetables) several times a week. -make at least half of the grain selections whole grains. -select fat-free or low-fat milk products. -look for foods that provide at least 10% of the daily value for fiber, vitamin a, vitamin c, iron, and calcium from a variety of sources. -fats choose foods within each group that are lean, low fat, or fat-free. -look for foods that describe their fat, saturated fat, trans fat, and cholesterol contents as free, less, low, light, reduced, lean, or extra lean. -choose foods within each group that have little added fat. -look for foods that provide no more than 5% of the daily value for fat, saturated fat, and cholesterol. -carbohydrates choose fiber-rich fruits, vegetables, and whole grains often. -look for foods that describe their sugar contents as free or reduced. -choose foods and beverages within each group that have little added sugars. -a food may be high in sugar if its ingredients list begins with or contains several of the following: sugar, sucrose, fructose, maltose, lactose, honey, syrup, corn syrup, high-fructose corn syrup, molasses, evaporated cane juice, or fruit juice concentrate. -sodium and potassium choose foods within each group that are low in salt or sodium. -look for foods that describe their salt and sodium contents as free, low, or reduced. -choose potassium-rich foods such as fruits and vegetables. -look for foods that provide no more than 5% of the daily value for sodium. -alcoholic beverages food safety use sensibly and in moderation (no more than one drink a day for women and two drinks a day for men). -look for foods that provide at least 10% of the daily value for potassium. -light beverages contain fewer kcalories and less alcohol than regular versions. -follow the safe handling instructions on packages of meat and other safety instructions, such as keep refrigerated, on packages of perishable foods. -planning a healthy diet 61 in summary food labels provide consumers with information they need to select foods that will help them meet their nutrition and health goals. -when labels contain rele- vant information presented in a standardized, easy-to-read format, consumers are well prepared to plan and create healthful diets. -this chapter provides the links to go from dietary guidelines to buying groceries and offers helpful tips for selecting nutritious foods. -for additional information on foods, including organic foods, irradiated foods, genetically modified foods, and more, turn to chapter 19. nutrition portfolio www.thomsonedu.com/thomsonnow the secret to making healthy food choices is learning to incorporate the 2005 dietary guidelines and the usda food guide into your decision-making process. -compare the foods you typically eat daily with the usda food guide recom- mendations for your energy needs (see table 2-3 on p. 41 and table 2-4 on p. 44), making note of which food groups are usually over- or underrepresented. -describe your choices within each food group from day to day and include realistic suggestions for enhancing the variety in your diet. -write yourself a letter describing the dietary changes you can make to improve your chances of enjoying good health. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 2, then to nutrition on the net. -search for diet and food labels at the u.s. government health information site: www.healthfinder.gov learn more about the dietary guidelines for americans: www.healthierus.gov/dietaryguidelines find canadian information on nutrition guidelines and food labels at: www.hc-sc.gc.ca learn more about the usda food guide and mypyramid: mypyramid.gov visit the usda food guide section (including its ethnic/cul- tural pyramids) of the u.s. department of agriculture: www.nal.usda.gov/fnic visit the traditional diet pyramids for various ethnic groups at oldways preservation and exchange trust: www.oldwayspt.org search for exchange lists at the american diabetes associ- ation: www.diabetes.org learn more about food labeling from the food and drug administration: www.cfsan.fda.gov search for food labels at the international food information council: www.ific.org assess your diet at the cnpp interactive healthy eating index: www.usda.gov/cnpp get healthy eating tips from the 5 a day programs: www.5aday.gov or www.5aday.org nutrition calculations for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 2, then to nutrition calculations. -these problems will give you practice in doing simple nutrition-related calculations. -although the situations are hypothetical, the numbers are real, and calculating the an- swers (check them on p. 63) provides a valuable nutrition lesson. -be sure to show your calculations for each problem. -62 chapter 2 1. read a food label. -look at the cereal label in figure 2-8 and answer the following questions: a. what is the size of a serving of cereal? -b. how many kcalories are in a serving? -c. how much fat is in a serving? -d. how many kcalories does this represent? -e. what percentage of the kcalories in this product comes from fat? -f. what does this tell you? -g. what is the % daily value for fat? -h. what does this tell you? -i. does this cereal meet the criteria for a low-fat prod- uct (refer to the glossary on p. 58)? -j. how much fiber is in a serving? -k. read the daily value chart on the lower section of the label. -what is the daily value for fiber? -study questions l. what percentage of the daily value for fiber does a serving of the cereal contribute? -show the calcula- tion the label-makers used to come up with the % daily value for fiber. -m. what is the predominant ingredient in the cereal? -n. have any nutrients been added to this cereal (is it fortified)? -2. calculate a personal daily value. -the daily values on food labels are for people with a 2000-kcalorie intake. -a. suppose a person has a 1600-kcalorie energy allowance. -use the calculation factors listed in table 2-9 to calculate a set of personal daily values based on 1600 kcalories. -show your calculations. -b. revise the % daily value chart of the cereal label in figure 2-8 based on your daily values for a 1600- kcalorie diet. -to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -spoons of peanut butter that also provide 0.5 milligram of iron but 188 kcalories is using the principle of nutrient: these questions will help you review this chapter. -you will find the answers in the discussions on the pages provided. -1. name the diet-planning principles and briefly describe how each principle helps in diet planning. -(pp. -37 39) a. control. -b. density. -c. adequacy. -d. moderation. -3. which of the following is consistent with the dietary 2. what recommendations appear in the dietary guidelines guidelines for americans? -for americans? -(pp. -39 40) 3. name the five food groups in the usda food guide and identify several foods typical of each group. -explain how such plans group foods and what diet-planning princi- ples the plans best accommodate. -how are food group plans used, and what are some of their strengths and weaknesses? -(pp. -41 47) 4. review the dietary guidelines. -what types of grocery selections would you make to achieve those recommen- dations? -(pp. -40, 48 53) 5. what information can you expect to find on a food label? -how can this information help you choose between two similar products? -(pp. -54 57) 6. what are the daily values? -how can they help you meet health recommendations? -(pp. -55 57) 7. describe the differences between nutrient claims, health claims, and structure-function claims. -(pp. -58 59) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 63. -1. the diet-planning principle that provides all the essen- tial nutrients in sufficient amounts to support health is: a. balance. -b. variety. -c. adequacy. -d. moderation. -2. a person who chooses a chicken leg that provides 0.5 milligram of iron and 95 kcalories instead of two table- a. choose a diet restricted in fat and cholesterol. -b. balance the food you eat with physical activity. -c. choose a diet with plenty of milk products and meats. -d. eat an abundance of foods to ensure nutrient adequacy. -4. according to the usda food guide, added fats and sug- ars are counted as: a. meats and grains. -b. nutrient-dense foods. -c. discretionary kcalories. -d. oils and carbohydrates. -5. foods within a given food group of the usda food guide are similar in their contents of: a. energy. -b. proteins and fibers. -c. vitamins and minerals. -d. carbohydrates and fats. -6. in the exchange system, each portion of food on any given list provides about the same amount of: a. energy. -b. satiety. -c. vitamins. -d. minerals. -7. enriched grain products are fortified with: a. fiber, folate, iron, niacin, and zinc. -b. thiamin, iron, calcium, zinc, and sodium. -c. iron, thiamin, riboflavin, niacin, and folate. -d. folate, magnesium, vitamin b6, zinc, and fiber. -8. food labels list ingredients in: a. alphabetical order. -b. ascending order of predominance by weight. -c. descending order of predominance by weight. -d. manufacturer s order of preference. -9. milk builds strong bones is an example of a: a. health claim. -b. nutrition fact. -c. nutrient content claim. -d. structure-function claim. -planning a healthy diet 63 10. daily values on food labels are based on a: a. -1500-kcalorie diet. -b. -2000-kcalorie diet. -c. 2500-kcalorie diet. -d. 3000-kcalorie diet. -ments, journal of the american dietetic associa- tion 105 (2005): 1300 1311. economics and nutrition review 14 (2002): 71 73. -7. r. ranganathan and coauthors, the nutri- 10. dietary reference intakes (dris) for food tional impact of dairy product consumption on dietary intakes of adults (1995 1996): the bogalusa heart study, journal of the american dietetic association 105 (2005): 1391 1400; l. g. weinberg, l. a. berner, and j. e. groves, nutrient contributions of dairy foods in the united states, continuing survey of food intakes by individuals, 1994 1996, 1998, journal of the american dietetic association 104 (2004): 895 902. -8. l. legault and coauthors, 2000 2001 food label and package survey: an update on prevalence of nutrition labeling and claims on processed, packaged foods, journal of the american dietetic association 104 (2004): 952 958. -9. d. herring and coauthors, serving sizes in the food guide pyramid and on the nutrition facts label: what s different and why? -family labeling, american journal of clinical nutrition 83 (2006): suppl; t. philipson, government perspective: food labeling, american journal of clinical nutrition 82 (2005): 262s 264s; the national academy of sciences, dietary refer- ence intakes: guiding principles for nutrition labeling and fortification (2004), http://www.nap.edu/openbook/0309091438/ html/r1.html. -11. p. williams, consumer understanding and use of health claims for foods, nutrition re- views 63 (2005): 256 264. -12. k. a. donato, national health education programs to promote healthy eating and physical activity, nutrition reviews 64 (2006): s65 s70. -references 1. s. p. murphy and coauthors, simple measures of dietary variety are associated with im- proved dietary quality, journal of the american dietetic association 106 (2006): 425 429. -2. u.s. department of agriculture and u.s. department of health and human services, dietary guidelines for americans, 2005, available at www.healthierus.gov/dietaryguidelines. -3. position of the american dietetic association and dietitians of canada: vegetarian diets, journal of the american dietetic association 103 (2003): 748 765. -4. j. r. backstrand, the history and future of food fortification in the united states: a public health perspective, nutrition reviews 60 (2002): 15 26. -5. as cited in 21 code of federal regulations food and drugs, section 104.20, 45 federal register 6323, january 25, 1980, as amended in 58 federal register 2228, january 6, 1993. -6. position of the american dietetic association: food fortification and nutritional supple- answers nutrition calculations 1. a. -3 4 cup (28 g) b. -110 kcalories c. 1 g fat d. 9 kcalories e. 9 kcal (cid:6) 110 kcal (cid:2) 0.08 0.08 (cid:5) 100 (cid:2) 8% f. this cereal derives 8 percent of its kcalories from fat g. 2% h. a serving of this cereal provides 2 percent of the 65 grams of fat recommended for a 2000-kcalorie diet i. yes j. -1.5 g fiber k. 25 g l. 1.5 g (cid:6) 25 g (cid:2) 0.06 0.06 (cid:5) 100 (cid:2) 6% m. corn n. yes saturated fat: 1600 kcal (cid:5) 0.10 (cid:2) 160 kcal from saturated fat 160 kcal (cid:6) 9 kcal/g (cid:2) 18 g saturated fat cholesterol: 300 mg carbohydrate: 1600 kcal (cid:5) 0.60 (cid:2) 960 kcal from carbohydrate 960 kcal (cid:6) 4 kcal/g (cid:2) 240 g carbohydrate fiber: 1600 kcal (cid:6) 1000 kcal (cid:2) 1.6 1.6 (cid:5) 11.5 g (cid:2) 18.4 g fiber protein: 1600 kcal (cid:5) 0.10 (cid:2) 160 kcal from protein 160 kcal (cid:6) 4 kcal/g (cid:2) 40 g protein sodium: 2400 mg potassium: 3500 mg b. total fat saturated fat cholesterol sodium total carbohydrate dietary fiber 2% 0% 0% 10% 10% 8% (1 g (cid:6) 53 g) (0 g (cid:6) 18 g) (no calculation needed) (no calculation needed) (23 g (cid:6) 240 g) (1.5 g (cid:6) 18.4 g) 2. a. daily values for 1600-kcalorie diet: fat: 1600 kcal (cid:5) 0.30 (cid:2) 480 kcal from fat 480 kcal (cid:6) 9 kcal/g (cid:2) 53 g fat study questions (multiple choice) 1. c 9. d 2. b 3. b 4. c 5. c 6. a 7. c 8. c 10. b highlight 2 vegetarian diets the waiter presents this evening s specials: a fresh spinach salad topped with mandarin oranges, raisins, and sunflower seeds, served with a bowl of pasta smothered in a mush- room and tomato sauce and topped with grated parmesan cheese. -then this one: a salad made of chopped parsley, scallions, cel- ery, and tomatoes mixed with bulgur wheat and dressed with olive oil and lemon juice, served with a spinach and feta cheese pie. -do these meals sound good to you? -or is something missing . -. -. -a pork chop or ribeye, perhaps? -would vegetarian fare be acceptable to you some of the time? -most of the time? -ever? -perhaps it is helpful to recognize that di- etary choices fall along a continuum from one end, where peo- ple eat no meat or foods of animal origin, to the other end, where they eat generous quantities daily. -meat s place in the diet has been the subject of much research and controversy, as this high- light will reveal. -one of the missions of this highlight, in fact, is to identify the range of meat intakes most compatible with health. -the health benefits of a primarily vegetarian diet seem to have encouraged many people to eat more vegetarian meals. -the pop- ular press refers to these part-time vegetarians who eat small amounts of meat from time to time as flexitarians. -people who choose to exclude meat and other animal-de- rived foods from their diets today do so for many of the same reasons the greek philosopher pythagoras cited in the sixth century b.c. -: physical health, ecological responsibility, and philosophical concerns. -they might also cite world hunger issues, economic reasons, eth- ical concerns, or religious beliefs as motivat- ing factors. -whatever their reasons and even if they don t have a particular reason people who exclude meat will be better pre- pared to plan well-balanced meals if they understand the nutrition and health implica- tions of vegetarian diets. -. -c n i , s o i d u t s a r o l o p vegetarians generally are categorized, not by their motiva- tions, but by the foods they choose to exclude (see the glossary below). -some people exclude red meat only; some also exclude chicken or fish; others also exclude eggs; and still others exclude milk and milk products as well. -in fact, finding agreement on the definition of the term vegetarian is a challenge.1 as you will see, though, the foods a person excludes are not nearly as important as the foods a person includes in the diet. -veg- etarian diets that include a variety of whole grains, vegetables, legumes, nuts, and fruits offer abundant complex carbohydrates and fibers, an assortment of vitamins and minerals, a mixture of phytochemicals, and little fat characteristics that reflect current dietary recommendations aimed at promoting health and reduc- ing obesity. -each of these foods whole grains, vegetables, legumes, nuts, and fruits independently reduces the risk for sev- eral chronic diseases.2 this highlight examines the health benefits and potential problems of vegetarian diets and shows how to plan a well-balanced vegetarian diet. -g lossary lactovegetarians: people who include milk and milk products, but exclude meat, poultry, fish, seafood, and eggs from their diets. -lacto (cid:2) milk lacto-ovo-vegetarians: people who include milk, milk products, and eggs, but exclude meat, poultry, fish, and seafood from their diets. -ovo (cid:2) egg macrobiotic diets: extremely restrictive diets limited to a few grains and vegetables; based on metaphysical beliefs and not on nutrition. -a macrobiotic diet might consist of brown rice, miso soup, and sea vegetables, for example. -meat replacements: products formulated to look and taste like meat, fish, or poultry; usually made of textured vegetable protein. -omnivores: people who have no formal restriction on the eating of any foods. -omni (cid:2) all vores (cid:2) to eat tempeh (tem-pay): a fermented soybean food, rich in protein and fiber. -textured vegetable protein: processed soybean protein used in vegetarian products such as soy burgers; see also meat replacements. -tofu (toe-foo): a curd made from soybeans, rich in protein and often fortified with calcium; used in many asian and vegetarian dishes in place of meat. -vegans (vee-gans): people who exclude all animal-derived foods (including meat, poultry, fish, eggs, and dairy products) from their diets; also called pure vegetarians, strict vegetarians, or total vegetarians. -vegetarians: a general term used to describe people who exclude meat, poultry, fish, or other animal-derived foods from their diets. -64 vegetarian diets 65 health benefits of vegetarian diets eating meat. -some research suggests that soy protein and phyto- chemicals may be responsible for some of these health benefits (as highlight 13 explains in greater detail).11 research on the health implications of vegetarian diets would be relatively easy if vegetarians differed from other people only in not eating meat. -many vegetarians, however, have also adopted lifestyles that may differ from many omnivores: they typically use no tobacco or illicit drugs, use little (if any) alcohol, and are physically active. -researchers must account for these lifestyle dif- ferences before they can determine which aspects of health cor- relate just with diet. -even then, correlations merely reveal what health factors go with the vegetarian diet, not what health effects may be caused by the diet. -despite these limitations, research findings suggest that well-planned vegetarian diets offer sound nutrition and health benefits to adults.3 dietary patterns that in- clude very little, if any, meat may even increase life expectancy.4 weight control in general, vegetarians maintain a lower and healthier body weight than nonvegetarians.5 vegetarians lower body weights correlate with their high intakes of fiber and low intakes of fat. -be- cause obesity impairs health in a number of ways, this gives veg- etarians a health advantage. -blood pressure vegetarians tend to have lower blood pressure and lower rates of hypertension than nonvegetarians. -appropriate body weight helps to maintain a healthy blood pressure, as does a diet low in total fat and saturated fat and high in fiber, fruits, vegetables, and soy pro- tein.6 lifestyle factors also influence blood pressure: smoking and alcohol intake raise blood pressure, and physical activity lowers it. -heart disease the incidence of heart disease and related deaths is much lower for vegetarians than for meat eaters. -the dietary factor most di- rectly related to heart disease is saturated animal fat, and in gen- eral, vegetarian diets are lower in total fat, saturated fat, and cholesterol than typical meat-based diets.7 the fats common in plant-based diets the monounsaturated fats of olives, seeds, and nuts and the polyunsaturated fats of vegetable oils are associ- ated with a decreased risk of heart disease.8 furthermore, vege- tarian diets are generally higher in dietary fiber, antioxidant vitamins, and phytochemicals all factors that help control blood lipids and protect against heart disease.9 many vegetarians include soy products such as tofu in their diets. -soy products may help to protect against heart disease be- cause they contain polyunsaturated fats, fiber, vitamins, and min- erals, and little saturated fat.10 even when intakes of energy, protein, carbohydrate, total fat, saturated fat, unsaturated fat, al- cohol, and fiber are the same, people eating meals based on tofu have lower blood cholesterol and triglyceride levels than those cancer vegetarians have a significantly lower rate of cancer than the gen- eral population. -their low cancer rates may be due to their high intakes of fruits and vegetables (as highlight 11 explains). -in fact, the ratio of vegetables to meat may be the most relevant dietary factor responsible for cancer prevention.12 some scientific findings indicate that vegetarian diets are asso- ciated not only with lower cancer mortality in general, but also with lower incidence of cancer at specific sites as well, most no- tably, colon cancer.13 people with colon cancer seem to eat more meat, more saturated fat, and fewer vegetables than do people without colon cancer. -high-protein, high-fat, low-fiber diets cre- ate an environment in the colon that promotes the development of cancer in some people. -a high-meat diet has been associated with stomach cancer as well.14 other diseases in addition to obesity, hypertension, heart disease, and cancer, vegetarian diets may help prevent diabetes, osteoporosis, diver- ticular disease, gallstones, and rheumatoid arthritis.15 these health benefits of a vegetarian diet depend on wise diet planning. -vegetarian diet planning the vegetarian has the same meal-planning task as any other per- son using a variety of foods to deliver all the needed nutrients within an energy allowance that maintains a healthy body weight (as discussed in chapter 2). -vegetarians who include milk prod- ucts and eggs can meet recommendations for most nutrients about as easily as nonvegetarians. -such diets provide enough en- ergy, protein, and other nutrients to support the health of adults and the growth of children and adolescents. -vegetarians who exclude milk products and eggs can select legumes, nuts, and seeds and products made from them, such as peanut butter, tempeh, and tofu, from the meat group. -those who do not use milk can use soy milk a product made from soybeans that provides similar nutrients if fortified with calcium, vitamin d, and vitamin b12. -the mypyramid resources include tips for planning vegetarian diets using the usda food guide. -in addition, several food guides have been developed specifically for vegetarian diets.16 they all address the particular nutrition concerns of vegetarians, but differ slightly. -figure h2-1 presents one version. -when selecting from the vegetable and fruit groups, vegetarians should emphasize particularly good sources of calcium and iron, respectively. -green leafy vegetables, for example, provide almost five times as much calcium per serving as other vegetables. -similarly, dried fruits de- serve special notice in the fruit group because they deliver six 66 highlight 2 figure h2-1 an example of a vegetarian food pyramid review figure 2 1 and table 2 3 to find recommended daily amounts from each food group, serving size equivalents, examples of common foods within each group, and the most notable nutrients for each group. -tips for planning a vege- tarian diet can be found at mypyramid.gov. -who adopt only plant-based diets are likely to meet protein needs provided that their en- ergy intakes are adequate and the protein sources varied.18 the proteins of whole grains, legumes, seeds, nuts, and vegetables can provide adequate amounts of all the amino acids. -an advantage of many vegetar- ian sources of protein is that they are gener- ally lower in saturated fat than meats and are often higher in fiber and richer in some vita- mins and minerals. -vegetarians sometimes use meat replace- ments made of textured vegetable pro- tein (soy protein). -these foods are formulated to look and taste like meat, fish, or poultry. -many of these products are fortified to provide the vitamins and minerals found in animal sources of protein. -a wise vegetarian learns to use a variety of whole, unrefined foods often and commercially prepared foods less fre- quently. -vegetarians may also use soy prod- ucts such as tofu to bolster protein intake. -source: gc nutrition council, 2006, adapted from usda 2005 dietary guidelines and www.mypyramid.gov. -copies can be ordered from 301-680-6717. times as much iron as other fruits. -the milk group features forti- fied soy milks for those who do not use milk, cheese, or yogurt. -the meat group is called proteins and includes legumes, soy products, nuts, and seeds. -a group for oils encourages the use of vegetable oils, nuts, and seeds rich in unsaturated fats and omega-3 fatty acids. -to ensure adequate intakes of vitamin b12, vitamin d, and calcium, vegetarians need to select fortified foods or take supplements daily. -the vegetarian food pyramid is flexible enough that a variety of people can use it: people who have adopted various vegetarian diets, those who want to make the transition to a vegetarian diet, and those who simply want to in- clude more plant-based meals in their diet. -like mypyramid, this vegetarian food pyramid also encourages physical activity. -most vegetarians easily obtain large quantities of the nutrients that are abundant in plant foods: thiamin, folate, and vitamins b6, c, a, and e. vegetarian food guides help to ensure adequate intakes of the main nutrients vegetarian diets might otherwise lack: protein, iron, zinc, calcium, vitamin b12, vitamin d, and omega-3 fatty acids. -protein the protein rda for vegetarians is the same as for others, although some have suggested that it should be higher because of the lower di- gestibility of plant proteins.17 lacto-ovo-vegetarians, who use an- imal-derived foods such as milk and eggs, receive high-quality proteins and are likely to meet their protein needs. -even those iron getting enough iron can be a problem even for meat eaters, and those who eat no meat must pay special attention to their iron in- take. -the iron in plant foods such as legumes, dark green leafy vegetables, iron-fortified ce- reals, and whole-grain breads and cereals is poorly absorbed.19 because iron absorption from a vegetarian diet is low, the iron rda for vegetarians is higher than for others (see chapter 13 for more details). -fortunately, the body seems to adapt to a vegetarian diet by absorbing iron more efficiently. -furthermore, iron absorption is enhanced by vitamin c, and vegetarians typically eat many vita- min c rich fruits and vegetables. -consequently, vegetarians suf- fer no more iron deficiency than other people do.20 zinc zinc is similar to iron in that meat is its richest food source, and zinc from plant sources is not well absorbed.21 in addition, soy, which is commonly used as a meat alternative in vegetarian meals, interferes with zinc absorption. -nevertheless, most vege- tarian adults are not zinc deficient. -perhaps the best advice to vegetarians regarding zinc is to eat a variety of nutrient-dense foods; include whole grains, nuts, and legumes such as black- eyed peas, pinto beans, and kidney beans; and maintain an ade- quate energy intake. -for those who include seafood in their diets, oysters, crabmeat, and shrimp are rich in zinc. -calcium the calcium intakes of lactovegetarians are similar to those of the general population, but people who use no milk products risk deficiency. -careful planners select calcium-rich foods, such as cal- cium-fortified juices, soy milk, and breakfast cereals, in ample quantities regularly. -this advice is especially important for chil- dren and adolescents. -soy formulas for infants are fortified with calcium and can be used in cooking, even for adults. -other good calcium sources include figs, some legumes, some green vegeta- bles such as broccoli and turnip greens, some nuts such as al- monds, certain seeds such as sesame seeds, and calcium-set tofu. -* the choices should be varied because calcium absorption from some plant foods may be limited (as chapter 12 explains). -vitamin b12 the requirement for vitamin b12 is small, but this vitamin is found only in animal-derived foods. -consequently, vegetarians, in general, and vegans who eat no foods of animal original, in particular, may not get enough vitamin b12 in their diets.22 fer- mented soy products such as tempeh may contain some vita- min b12 from the bacteria, but unfortunately, much of the vitamin b12 found in these products may be an inactive form. -seaweeds such as nori and chlorella supply some vitamin b12, but not much, and excessive intakes of these foods can lead to iodine toxicity. -to defend against vitamin b12 deficiency, vegans must rely on vita- min b12-fortified sources (such as soy milk or breakfast cereals) or supplements. -without vitamin b12, the nerves suffer damage, leading to such health consequences as loss of vision. -vitamin d people who do not use vitamin d fortified foods and do not receive enough exposure to sunlight to synthesize adequate vitamin d may need supplements to defend against bone loss. -this is particularly important for infants, children, and older adults. -in northern cli- mates during winter months, young children on vegan diets can readily develop rickets, the vitamin d deficiency disease. -omega-3 fatty acids both chapter 5 and highlight 5 describe the health benefits of unsaturated fats, most notably the omega-3 fatty acids com- *calcium salts are often added during processing to coagulate the tofu. -vegetarian diets 67 monly found in fatty fish. -to obtain sufficient amounts of omega- 3 fatty acids, vegetarians need to consume flaxseed, walnuts, soy- beans, and their oils. -healthy food choices in general, adults who eat vegetarian diets have lowered their risks of mortality and several chronic diseases, including obesity, high blood pressure, heart disease, and cancer. -but there is noth- ing mysterious or magical about the vegetarian diet; vegetarian- ism is not a religion like buddhism or hinduism, but merely an eating plan that selects plant foods to deliver needed nutrients. -the quality of the diet depends not on whether it includes meat, but on whether the other food choices are nutritionally sound. -a diet that includes ample fruits, vegetables, whole grains, legumes, nuts, and seeds is higher in fiber, antioxidant vitamins, and phytochemicals, and lower in saturated fats than meat-based diets. -variety is key to nutritional adequacy in a vegetarian diet. -restrictive plans, such as macrobiotic diets, that limit selec- tions to a few grains and vegetables cannot possibly deliver a full array of nutrients. -if not properly balanced, any diet vegetarian or otherwise can lack nutrients. -poorly planned vegetarian diets typically lack iron, zinc, calcium, vitamin b12, and vitamin d; without planning, the meat eater s diet may lack vitamin a, vitamin c, folate, and fiber, among others. -quite simply, the negative health aspects of any diet, including vegetarian diets, reflect poor diet planning. -careful attention to energy intake and specific problem nutrients can ensure adequacy. -keep in mind, too, that diet is only one factor influencing health. -whatever a diet consists of, its context is also important: no smoking, alcohol consumption in moderation (if at all), reg- ular physical activity, adequate rest, and medical attention when needed all contribute to a healthy life. -establishing these healthy habits early in life seems to be the most important step one can take to reduce the risks of later diseases (as highlight 16 explains). -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 2, then to highlights nutrition on the net. -search for vegetarian at the food and drug administration s site: www.fda.gov visit the vegetarian resource group: www.vrg.org review another vegetarian diet pyramid developed by oldways preservation & exchange trust: www.oldwayspt.org 68 highlight 2 references 1. s. i. barr and g. e. chapman, perceptions and practices of self-defined current vegetarian, former vegetarian, and nonvegetarian women, journal of the american dietetic associ- ation 102 (2002): 354-360. j. sabate, the contribution of vegetarian diets to human health, forum of nutrition 56 (2003): 218-220. -2. -3. position of the american dietetic association and dietitians of canada: vegetarian diets, journal of the american dietetic association 103 (2003): 748-765; j. sabat , the contribution of vegetarian diets to health and disease: a paradigm shift? -american journal of clinical nutrition 78 (2003): 502s-507s. -4. p. n. singh, j. sabat , and g. e. fraser, does low meat consumption increase life expectancy in humans? -american journal of clinical nutrition 78 (2003): 526s-532s. -5. p. k. newby, k. l. tucker, and a. wolk, risk of overweight and obesity among semivegetar- ian, lactovegetarian, and vegan women, american journal of clinical nutrition 81 (2005): 1267-1274; n. brathwaite and coau- thors, obesity, diabetes, hypertension, and vegetarian status among seventh-day adven- tists in barbados, ethnicity and disease 13 (2003): 34-39; e. h. haddad and j. s. tanz- man, what do vegetarians in the united states eat? -american journal of clinical nutri- tion 78 (2003): 626s-632s. -6. s. e. berkow and n. d. barnard, blood pres- sure regulation and vegetarian diets, nutrition reviews 63 (2005): 1-8; l. j. appel, the effects of protein intake on blood pressure and cardiovascular disease, current opinion in lipidology 14 (2003): 55-59. -7. j. e. cade and coauthors, the uk women s cohort study: comparison of vegetarians, fish-eaters, and meat-eaters, public health nutrition 7 (2004): 871-878; e. h. haddad and j. s. tanzman, what do vegetarians in the united states eat? -american journal of clinical nutrition 78 (2003): 626s-632s. -8. third report of the national cholesterol educa- tion program (ncep) expert panel on detection, evaluation, and treatment of high blood choles- terol in adults (adult treatment panel iii), nih publication no. -02-5215 (bethesda, md. -: national heart, lung, and blood institute, 2002). -9. f. b. hu, plant-based foods and prevention of cardiovascular disease: an overview, american journal of clinical nutrition 78 (2003): 544s-551s. -10. f. m. sacks and coauthors, soy protein, isoflavones, and cardiovascular health: an american heart association science advisory for professionals from the nutrition commit- tee, circulation 113 (2006): 1034-1044. -11. b. l. mcveigh and coauthors, effect of soy protein varying in isoflavone content on serum lipids in healthy young men, ameri- can journal of clinical nutrition 83 (2006): 244-251; d. lukaczer and coauthors, effect of a low glycemic index diet with soy pro- tein and phytosterols on cvd risk factors in postmenopausal women, nutrition 22 (2006): 104-113; m. s. rosell and coauthors, soy intake and blood cholesterol concentra- tions: a cross-sectional study of 1033 pre- and postmenopausal women in the oxford arm of the european prospective investiga- tion into cancer and nutrition, american journal of clinical nutrition 80 (2004): 1391- 1396; s. tonstad, k. smerud, and l. hoie, a comparison of the effects of 2 doses of soy protein or casein on serum lipids, serum lipoproteins, and plasma total homocys- teine in hypercholesterolemic subjects, american journal of clinical nutrition 76 (2002): 78-84. -12. m. kapiszewska, a vegetable to meat con- sumption ratio as a relevant factor deter- mining cancer preventive diet: the mediterranean versus other european coun- tries, forum of nutrition 59 (2006): 130 153. -13. m. h. lewin and coauthors, red meat en- hances the colonic formation of the dna adduct o6-carboxymethyl guanine: implica- tions for colorectal cancer risk, cancer research 66 (2006): 1859-1865. -14. h. chen and coauthors, dietary patterns and adenocarcinoma of the esophagus and distal stomach, american journal of clinical nutrition 75 (2002): 137-144. -15. c. leitzmann, vegetarian diets: what are the advantages? -forum of nutrition 57 (2005): 147-156. -16. m. virginia, v. melina, and a. r. mangels, a new food guide for north american vegetari- ans, journal of the american dietetic association 103 (2003): 771-775; c. a. venti and c. s. johnston, modified food guide pyramid for lactovegetarians and vegans, journal of nutri- tion 132 (2002): 1050-1054. -17. venti and johnston, 2002; v. messina and a. r. mangels, considerations in planning vegan diets: children, journal of the american dietetic association 101 (2001): 661-669. -18. position of the american dietetic association and dietitians of canada, 2003. -19. j. r. hunt, moving toward a plant-based diet: are iron and zinc at risk? -nutrition reviews 60 (2002): 127-134. -20. c. l. larsson and g. k. johansson, dietary intake and nutritional status of young vegans and omnivores in sweden, american journal of clinical nutrition 76 (2002): 100-106. -21. hunt, 2002. -22. w. herrmann and coauthors, vitamin b12 status, particularly holotranscobalamin ii and methylmalonic acid concentrations, and hyperhomocysteinemia in vegetarians, american journal of clinical nutrition 78 (2003): 131-136. this page intentionally left blank foodcollection/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow figure 3.8: animated! -the digestive fate of a sandwich figure 3.11: animated! -the vascular system nutrition portfolio journal have you ever wondered what happens to the food you eat after you swallow it? -or how your body extracts nutrients from food? -have you ever marveled at how it all just seems to happen? -follow foods as they travel through the digestive system. -learn how a healthy digestive system transforms whatever food you give it whether sirloin steak and potatoes or tofu and brussels sprouts into the nutrients that will nourish the cells of your body. -digestion, absorption, and transport this chapter takes you on the journey that transforms the foods you eat into the nutrients featured in the later chapters. -then it follows the nutri- ents as they travel through the intestinal cells and into the body to do their work. -this introduction presents a general overview of the processes com- mon to all nutrients; later chapters discuss the specifics of digesting and absorbing individual nutrients. -digestion digestion is the body s ingenious way of breaking down foods into nutrients in preparation for absorption. -in the process, it overcomes many challenges without any conscious effort on your part. -consider these challenges: 1. human beings breathe, eat, and drink through their mouths. -air taken in through the mouth must go to the lungs; food and liquid must go to the stom- ach. -the throat must be arranged so that swallowing and breathing don t inter- fere with each other. -2. below the lungs lies the diaphragm, a dome of muscle that separates the upper half of the major body cavity from the lower half. -food must pass through this wall to reach the stomach. -3. the materials within the digestive tract should be kept moving forward, slowly but steadily, at a pace that permits all reactions to reach completion. -4. to move through the system, food must be lubricated with fluids. -too much would form a liquid that would flow too rapidly; too little would form a paste too dry and compact to move at all. -the amount of fluids must be regulated to keep the intestinal contents at the right consistency to move smoothly along. -5. when the digestive enzymes break food down, they need it in a finely divided form, suspended in enough liquid so that every particle is accessible. -once di- gestion is complete and the needed nutrients have been absorbed out of the tract and into the body, the system must excrete the remaining residue. -excret- ing all the water along with the solid residue, however, would be both wasteful and messy. -some water must be withdrawn to leave a paste just solid enough to be smooth and easy to pass. -6. the enzymes of the digestive tract are designed to digest carbohydrate, fat, and protein. -the walls of the tract, composed of living cells, are also made of c h a p t e r 3 chapter outline digestion anatomy of the digestive tract the muscular action of digestion the secretions of digestion the final stage absorption anatomy of the absorptive system a closer look at the intestinal cells the circulatory systems the vascular system the lymphatic system the health and regulation of the gi tract gastrointestinal bacteria gastrointestinal hormones and nerve pathways the system at its best highlight 3 common digestive problems digestion: the process by which food is broken down into absorbable units. -digestion = take apart absorption: the uptake of nutrients by the cells of the small intestine for transport into either the blood or the lymph. -absorb = suck in 71 72 chapter 3 s e g a m i r e t i p u j / x i p d o o f / i n i r g i l l e p e o j the process of digestion transforms all kinds of foods into nutrients. -the process of chewing is called mastication (mass-tih-kay-shun). -gastrointestinal (gi) tract: the digestive tract. -the principal organs are the stomach and intestines. -gastro = stomach intestinalis = intestine g lossary of gi anatomy terms carbohydrate, fat, and protein. -these cells need protection against the action of the powerful digestive juices that they secrete. -7. once waste matter has reached the end of the tract, it must be excreted, but it would be inconvenient and embarrassing if this function occurred continu- ously. -provision must be made for periodic, voluntary evacuation. -the following sections show how the body elegantly and efficiently handles these challenges. -anatomy of the digestive tract the gastrointestinal (gi) tract is a flexible muscular tube that extends from the mouth, through the esophagus, stomach, small intestine, large intestine, and rectum to the anus. -figure 3-1 traces the path followed by food from one end to the other. -in a sense, the human body surrounds the gi tract. -the inner space within the gi tract, called the lumen, is continuous from one end to the other. -(gi anatomy terms ap- pear in boldface type and are defined in the accompanying glossary.) -only when a nutrient or other substance finally penetrates the gi tract s wall does it enter the body proper; many materials pass through the gi tract without being digested or absorbed. -mouth the process of digestion begins in the mouth. -as you chew, your teeth crush large pieces of food into smaller ones, and fluids from foods, beverages, and salivary glands blend with these pieces to ease swallowing. -fluids also help dissolve the food so that you can taste it; only particles in solution can react with taste buds. -when stimulated, the taste buds detect one, or a combination, of the four basic taste sensations: sweet, sour, bitter, and salty. -some scientists also include the flavor asso- ciated with monosodium glutamate, sometimes called savory or its asian name, umami (oo-mom-ee). -in addition to these chemical triggers, aroma, texture, and temperature also affect a food s flavor. -in fact, the sense of smell is thousands of times more sensitive than the sense of taste. -the tongue allows you not only to taste food, but also to move food around the mouth, facilitating chewing and swallowing. -when you swallow a mouthful of these terms are listed in order from start to end of the digestive system. -lumen (loo-men): the space within a vessel, such as the intestine. -mouth: the oral cavity containing the tongue and teeth. -pharynx (fair-inks): the passageway leading from the nose and mouth to the larynx and esophagus, respectively. -epiglottis (epp-ih-glott-iss): cartilage in the throat that guards the entrance to the trachea and prevents fluid or food from entering it when a person swallows. -epi (cid:2) upon (over) glottis (cid:2) back of tongue esophagus (ee-soff-ah-gus): the food pipe; the conduit from the mouth to the stomach. -sphincter (sfink-ter): a circular muscle surrounding, and able to close, a body opening. -sphincters are found at specific points along the gi tract and regulate the flow of food particles. -sphincter (cid:2) band (binder) food and absorption of nutrients. -its segments are the duodenum, jejunum, and ileum. -esophageal (ee-sof-ah-gee-al) sphincter: a sphincter muscle at the upper or lower end of the esophagus. -the lower esophageal sphincter is also called the cardiac sphincter. -stomach: a muscular, elastic, saclike portion of the digestive tract that grinds and churns swallowed food, mixing it with acid and enzymes to form chyme. -pyloric (pie-lore-ic) sphincter: the circular muscle that separates the stomach from the small intestine and regulates the flow of partially digested food into the small intestine; also called pylorus or pyloric valve. -pylorus (cid:2) gatekeeper small intestine: a 10-foot length of small-diameter intestine that is the major site of digestion of gallbladder: the organ that stores and concentrates bile. -when it receives the signal that fat is present in the duodenum, the gallbladder contracts and squirts bile through the bile duct into the duodenum. -pancreas: a gland that secretes digestive enzymes and juices into the duodenum. -(the pancreas also secretes hormones into the blood that help to maintain glucose homeostasis.) -duodenum (doo-oh-deen-um, doo-odd-num): the top portion of the small intestine (about 12 fingers breadth long in ancient terminology). -duodecim (cid:2) twelve jejunum (je-joon-um): the first two-fifths of the small intestine beyond the duodenum. -ileum (ill-ee-um): the last segment of the small intestine. -ileocecal (ill-ee-oh-seek-ul) valve: the sphincter separating the small and large intestines. -large intestine or colon (coal-un): the lower portion of intestine that completes the digestive process. -its segments are the ascending colon, the transverse colon, the descending colon, and the sigmoid colon. -sigmoid (cid:2) shaped like the letter s (sigma in greek) appendix: a narrow blind sac extending from the beginning of the colon that stores lymph cells. -rectum: the muscular terminal part of the intestine, extending from the sigmoid colon to the anus. -anus (ay-nus): the terminal outlet of the gi tract. -digestive system: all the organs and glands associated with the ingestion and digestion of food. -figure 3 1 the gastrointestinal tract digestion, absorption, and transport 73 ingestion mouth chews and mixes food with saliva pharynx directs food from mouth to esophagus salivary glands secrete saliva (contains starch-digesting enzymes) epiglottis protects airway during swallowing trachea allows air to pass to and from lungs esophagus passes food from the mouth to the stomach esophageal sphincters allow passage from mouth to esophagus and from esophagus to stomach; prevent backflow from stomach to esophagus and from esophagus to mouth stomach adds acid, enzymes, and fluid; churns, mixes, and grinds food to a liquid mass pyloric sphincter allows passage from stomach to small intestine; prevents backflow from small intestine liver manufactures bile salts, detergent-like substances, to help digest fats gallbladder stores bile until needed bile duct conducts bile from the gallbladder to the small intestine salivary glands pharynx epiglottis upper esophageal sphincter esophagus mouth trachea (to lungs) lower esophageal sphincter liver gallbladder pyloric sphincter bile duct ileocecal valve appendix large intestine (colon) rectum anus appendix stores lymph cells small intestine secretes enzymes that digest all energy-yielding nutrients to smaller nutrient particles; cells of wall absorb nutrients into blood and lymph ileocecal valve (sphincter) allows passage from small to large intestine; prevents backflow from large intestine pancreas manufactures enzymes to digest all energy-yielding nutrients and releases bicarbonate to neutralize acid chyme that enters the small intestine pancreatic duct conducts pancreatic juice from the pancreas to the small intestine stomach pancreas pancreatic duct small intestine (duodenum, jejunum, ileum) large intestine (colon) reabsorbs water and minerals; passes waste (fiber, bacteria, and unabsorbed nutrients) along with water to the rectum rectum stores waste prior to elimination anus holds rectum closed; opens to allow elimination elimination food, it passes through the pharynx, a short tube that is shared by both the diges- tive system and the respiratory system. -to bypass the entrance to your lungs, the epiglottis closes off your air passages so that you don t choke when you swallow, thus resolving the first challenge. -(choking is discussed on pp. -92 93.) -after a mouthful of food has been swallowed, it is called a bolus. -bolus (boh-lus): a portion; with respect to food, the amount swallowed at one time. -bolos = lump 74 chapter 3 the ability of the gi tract muscles to move is called their motility (moh-til-ih-tee). -chyme (kime): the semiliquid mass of partly digested food expelled by the stomach into the duodenum. -chymos = juice peristalsis (per-ih-stall-sis): wavelike muscular contractions of the gi tract that push its contents along. -peri = around stellein = wrap esophagus to the stomach the esophagus has a sphincter muscle at each end. -during a swallow, the upper esophageal sphincter opens. -the bolus then slides down the esophagus, which passes through a hole in the diaphragm (chal- lenge 2) to the stomach. -the lower esophageal sphincter at the entrance to the stomach closes behind the bolus so that it proceeds forward and doesn t slip back into the esophagus (challenge 3). -the stomach retains the bolus for a while in its up- per portion. -little by little, the stomach transfers the food to its lower portion, adds juices to it, and grinds it to a semiliquid mass called chyme. -then, bit by bit, the stomach releases the chyme through the pyloric sphincter, which opens into the small intestine and then closes behind the chyme. -small intestine at the beginning of the small intestine, the chyme bypasses the opening from the common bile duct, which is dripping fluids (challenge 4) into the small intestine from two organs outside the gi tract the gallbladder and the pancreas. -the chyme travels on down the small intestine through its three seg- ments the duodenum, the jejunum, and the ileum almost 10 feet of tubing coiled within the abdomen. -* large intestine (colon) having traveled the length of the small intestine, the re- maining contents arrive at another sphincter (challenge 3 again): the ileocecal valve, at the beginning of the large intestine (colon) in the lower right side of the abdomen. -upon entering the colon, the contents pass another opening. -any in- testinal contents slipping into this opening would end up in the appendix, a blind sac about the size of your little finger. -the contents bypass this opening, however, and travel along the large intestine up the right side of the abdomen, across the front to the left side, down to the lower left side, and finally below the other folds of the intestines to the back of the body, above the rectum. -as the intestinal contents pass to the rectum, the colon withdraws water, leaving semisolid waste (challenge 5). -the strong muscles of the rectum and anal canal hold back this waste until it is time to defecate. -then the rectal muscles relax (chal- lenge 7), and the two sphincters of the anus open to allow passage of the waste. -the muscular action of digestion in the mouth, chewing, the addition of saliva, and the action of the tonguetransform food into a coarse mash that can be swallowed. -after swallowing, you are generally unaware of all the activity that follows. -as is the case with so much else that happens in the body, the muscles of the digestive tract meet internal needs without any con- scious effort on your part. -they keep things moving at just the right pace, slow enough to get the job done and fast enough to make progress. -peristalsis the entire gi tract is ringed with circular muscles. -surrounding these rings of muscle are longitudinal muscles. -when the rings tighten and the long muscles relax, the tube is constricted. -when the rings relax and the long muscles tighten, the tube bulges. -this action called peristalsis occurs continuously and pushes the intestinal contents along (challenge 3 again). -(if you have ever watched a lump of food pass along the body of a snake, you have a good picture of how these muscles work.) -the waves of contraction ripple along the gi tract at varying rates and intensi- ties depending on the part of the gi tract and on whether food is present. -for exam- ple, waves occur three times per minute in the stomach, but they speed up to ten times per minute when chyme reaches the small intestine. -when you have just eaten a meal, the waves are slow and continuous; when the gi tract is empty, the intestine is quiet except for periodic bursts of powerful rhythmic waves. -peristalsis, * the small intestine is almost 21/2 times shorter in living adults than it is at death, when muscles are relaxed and elongated. -along with sphincter muscles located at key places, keeps things moving along. -stomach action the stomach has the thickest walls and strongest muscles of all the gi tract organs. -in addition to the circular and longi- tudinal muscles, it has a third layer of diagonal muscles that also alter- nately contract and relax (see figure 3-2). -these three sets of muscles work to force the chyme downward, but the pyloric sphincter usually re- mains tightly closed, preventing the chyme from passing into the duo- denum of the small intestine. -as a result, the chyme is churned and forced down, hits the pyloric sphincter, and remains in the stomach. -meanwhile, the stomach wall releases gastric juices. -when the chyme is completely liquefied, the pyloric sphincter opens briefly, about three times a minute, to allow small portions of chyme to pass through. -at this point, the chyme no longer resembles food in the least. -segmentation the circular muscles of the intestines rhythmically contract and squeeze their contents (see figure 3-3). -these contractions, figure 3 3 peristalsis and segmentation digestion, absorption, and transport 75 figure 3 2 stomach muscles the stomach has three layers of muscles. -longitudinal circular diagonal the small intestine has two muscle layers that work together in peristalsis and segmentation. -circular muscles are inside. -longitudinal muscles are outside. -peristalsis chyme the inner circular muscles contract, tightening the tube and pushing the food forward in the intestine. -when the circular muscles relax, the outer longitudinal muscles contract, and the intestinal tube is loose. -as the circular and longitudinal muscles tighten and relax, the chyme moves ahead of the constriction. -segmentation chyme circular muscles contract, creating segments within the intestine. -as each set of circular muscles relaxes and contracts, the chyme is broken up and mixed with digestive juices. -these alternating contractions, occurring 12 to 16 times per minute, continue to mix the chyme and bring the nutrients into contact with the intestinal lining for absorption. -76 chapter 3 figure 3 4 an example of a sphincter muscle when the circular muscles of a sphincter contract, the passage closes; when they relax, the passage opens. -esophagus circular muscle longitudinal muscle called segmentation, mix the chyme and promote close contact with the digestive juices and the ab- sorbing cells of the intestinal walls before letting the contents move slowly along. -figure 3-3 illustrates peristalsis and segmentation. -stomach esophagus muscles relax, opening the passageway. -diaphragm muscles relax, opening the passageway. -diaphragm muscles contract, squeezing on the outside. -esophagus muscles contract, squeezing on the inside. -sphincter contractions sphincter muscles periodically open and close, allowing the contents of the gi tract to move along at a controlled pace (challenge 3 again). -at the top of the esophagus, the upper esophageal sphincter opens in response to swal- lowing. -at the bottom of the esopha- gus, the lower esophageal sphincter (sometimes called the cardiac sphinc- ter because of its proximity to the heart) prevents reflux of the stom- ach contents. -at the bottom of the stomach, the pyloric sphincter, which stays closed most of the time, holds the chyme in the stomach long enough for it to be thoroughly mixed with gastric juice and liquefied. -the pyloric sphincter also prevents the intestinal contents from backing up into the stomach. -at the end of the small intestine, the ileocecal valve performs a similar function, allowing the contents of the small intestine to empty into the large intestine. -finally, the tightness of the rectal muscle is a kind of safety device; together with the two sphincters of the anus, it prevents elimination until you choose to perform it voluntarily (challenge 7). -figure 3-4 illustrates how sphincter muscles contract and relax to close and open passageways. -the secretions of digestion the breakdown of food into nutrients requires secretions from five different or- gans: the salivary glands, the stomach, the pancreas, the liver (via the gallblad- der), and the small intestine. -these secretions enter the gi tract at various points along the way, bringing an abundance of water (challenge 3 again) and a vari- ety of enzymes. -enzymes are formally introduced in chapter 6, but for now a simple definition will suffice. -an enzyme is a protein that facilitates a chemical reaction making a molecule, breaking a molecule apart, changing the arrangement of a molecule, or exchanging parts of molecules. -as a catalyst, the enzyme itself remains un- changed. -the enzymes involved in digestion facilitate a chemical reaction known as hydrolysis the addition of water (hydro) to break (lysis) a molecule into smaller pieces. -the glossary (p. 77) identifies some of the common digestive en- zymes and related terms; later chapters introduce specific enzymes. -when learn- ing about enzymes, it helps to know that the word ending -ase denotes an enzyme. -enzymes are often identified by the organ they come from and the com- pounds they work on. -gastric lipase, for example, is a stomach enzyme that acts on lipids, whereas pancreatic lipase comes from the pancreas (and also works on lipids). -figure 3 5 the salivary glands the salivary glands secrete saliva into the mouth and begin the digestive process. -given the short time food is in the mouth, salivary enzymes contribute little to digestion. -salivary glands segmentation (seg-men-tay-shun): a periodic squeezing or partitioning of the intestine at intervals along its length by its circular muscles. -reflux: a backward flow. -re = back flux = flow catalyst (cat-uh-list): a compound that facilitates chemical reactions without itself being changed in the process. -saliva the salivary glands, shown in figure 3-5, squirt just enough saliva to moisten each mouthful of food so that it can pass easily down the esophagus (challenge 4). -(digestive glands and their secretions are defined in the glossary on digestion, absorption, and transport 77 p. -78.) -the saliva contains water, salts, mucus, and enzymes that initiate the diges- tion of carbohydrates. -saliva also protects the teeth and the linings of the mouth, esophagus, and stomach from attack by substances that might harm them. -gastric juice in the stomach, gastric glands secrete gastric juice, a mix- ture of water, enzymes, and hydrochloric acid, which acts primarily in pro- tein digestion. -the acid is so strong that it causes the sensation of heartburn if it happens to reflux into the esophagus. -highlight 3, following this chapter, dis- cusses heartburn, ulcers, and other common digestive problems. -the strong acidity of the stomach prevents bacterial growth and kills most bacteria that enter the body with food. -it would destroy the cells of the stomach as well, but for their natural defenses. -to protect themselves from gastric juice, the cells of the stomach wall secrete mucus, a thick, slippery, white substance that coats the cells, protecting them from the acid, enzymes, and disease-caus- ing bacteria that might otherwise harm them (challenge 6). -figure 3-6 shows how the strength of acids is measured in ph units. -note that the acidity of gastric juice registers below 2 on the ph scale stronger than vinegar. -the stomach enzymes work most efficiently in the stomach s strong acid, but the salivary enzymes, which are swallowed with food, do not work in acid this strong. -consequently, the salivary digestion of carbohydrate gradually ceases when the stomach acid penetrates each newly swallowed bolus of food. -when they enter the stomach, salivary enzymes become just other pro- teins to be digested. -pancreatic juice and intestinal enzymes by the time food leaves the stom- ach, digestion of all three energy nutrients (carbohydrates, fats, and proteins) has begun, and the action gains momentum in the small intestine. -there the pancreas contributes digestive juices by way of ducts leading into the duode- num. -the pancreatic juice contains enzymes that act on all three energy nu- trients, and the cells of the intestinal wall also possess digestive enzymes on their surfaces. -in addition to enzymes, the pancreatic juice contains sodium bicarbonate, which is basic or alkaline the opposite of the stomach s acid (review figure 3- 6). -the pancreatic juice thus neutralizes the acidic chyme arriving in the small intestine from the stomach. -from this point on, the chyme remains at a neutral or slightly alkaline ph. -the enzymes of both the intestine and the pancreas work best in this environment. -bile bile also flows into the duodenum. -the liver continuously produces bile, which is then concentrated and stored in the gallbladder. -the gallbladder squirts g lossary of digestive enzymes digestive enzymes: proteins found in protease (pro-tee-ase), an enzyme digestive juices that act on food substances, causing them to break down into simpler compounds. --ase (ace): a word ending denoting an enzyme. -the word beginning often identifies the compounds the enzyme works on. -examples include: carbohydrase (kar-boe-high-drase), an enzyme that hydrolyzes carbohydrates. -lipase (lye-pase), an enzyme that hydrolyzes lipids (fats). -that hydrolyzes proteins. -hydrolysis (high-drol-ih-sis): a chemical reaction in which a major reactant is split into two products, with the addition of a hydrogen atom (h) to one and a hydroxyl group (oh) to the other (from water, h2o). -(the noun is hydrolysis; the verb is hydrolyze.) -hydro (cid:2) water lysis (cid:2) breaking figure 3 6 the ph scale a substance s acidity or alkalinity is measured in ph units. -the ph is the negative logarithm of the hydrogen ion concentration. -each increment represents a tenfold increase in concentration of hydrogen particles. -this means, for example, that a ph of 2 is 1000 times stronger than a ph of 5. ph of common substances: basic 14 concentrated lye oven cleaner 13 12 11 household ammonia 10 9 8 7 6 5 4 3 2 1 0 baking soda bile pancreatic juice blood water saliva urine coffee orange juice vinegar lemon juice gastric juice battery acid ph neutral acidic the lower the ph, the higher the h+ ion con- centration and the stronger the acid. -a ph above 7 is alkaline, or base (a solution in which oh(cid:3) ions predominate). -ph: the unit of measure expressing a substance s acidity or alkalinity. -78 chapter 3 g lossary of digestive glands and their secretions these terms are listed in order from start to end of the digestive tract. -glands: cells or groups of cells that secrete materials for special uses in the body. -glands may be exocrine (eks-oh-crin) glands, secreting their materials out (into the digestive tract or onto the surface of the skin), or endocrine (en-doe-crin) glands, secreting their materials in (into the blood). -exo (cid:2) outside endo (cid:2) inside krine (cid:2) to separate salivary glands: exocrine glands that secrete saliva into the mouth. -saliva: the secretion of the salivary glands. -its principal enzyme begins carbohydrate digestion. -gastric glands: exocrine glands in the stomach wall that secrete gastric juice into the stomach. -gastro (cid:2) stomach gastric juice: the digestive secretion of the gastric glands of the stomach. -hydrochloric acid: an acid composed of hydrogen and chloride atoms (hcl) that is normally produced by the gastric glands. -mucus (myoo-kus): a slippery substance secreted by cells of the gi lining (and other body linings) that protects the cells from exposure to digestive juices (and other destructive agents). -the lining of the gi tract with its coat of mucus is a mucous membrane. -(the noun is mucus; the adjective is mucous.) -liver: the organ that manufactures bile. -(the liver s many other functions are described in chapter 7.) -bile: an emulsifier that prepares fats and oils for digestion; an exocrine secretion made by the liver, stored in the gallbladder, and released into the small intestine when needed. -emulsifier (ee-mul-sih-fire): a substance with both water- soluble and fat-soluble portions that promotes the mixing of oils and fats in a watery solution. -pancreatic (pank-ree-at-ic) juice: the exocrine secretion of the pancreas, containing enzymes for the digestion of carbohydrate, fat, and protein as well as bicarbonate, a neutralizing agent. -the juice flows from the pancreas into the small intestine through the pancreatic duct. -(the pancreas also has an endocrine function, the secretion of insulin and other hormones.) -bicarbonate: an alkaline compound with the formula hco3 that is secreted from the pancreas as part of the pancreatic juice. -(bicarbonate is also produced in all cell fluids from the dissociation of cabonic acid to help maintain the body s acid- base balance.) -stools: waste matter discharged from the colon; also called feces (fee-seez). -the bile into the duodenum of the small intestine when fat arrives there. -bile is not an enzyme; it is an emulsifier that brings fats into suspension in water so that enzymes can break them down into their component parts. -thanks to all these se- cretions, the three energy-yielding nutrients are digested in the small intestine (the summary on p. 80 provides a table of digestive secretions and their actions). -figure 3 7 the colon the colon begins with the ascending colon rising upward toward the liver. -it becomes the transverse colon as it turns and crosses the body toward the spleen. -the descending colon turns downward and becomes the sigmoid colon, which extends to the rectum. -along the way, the colon mixes the intestinal contents, absorbs water and salts, and forms stools. -transverse colon ascending colon end of small intestine descending colon sigmoid colon opening from small intestine to large intestine appendix rectum anus the final stage at this point, the three energy-yielding nutrients carbohy- drate, fat, and protein have been disassembled and are ready to be absorbed. -most of the other nutrients vita- mins, minerals, and water need no such disassembly; some vitamins and minerals are altered slightly during di- gestion, but most are absorbed as they are. -undigested residues, such as some fibers, are not absorbed. -instead, they continue through the digestive tract, providing a semisolid mass that helps exercise the muscles and keep them strong enough to perform peristalsis efficiently. -fiber also retains water, accounting for the pasty consistency of stools, and thereby carries some bile acids, some minerals, and some additives and contaminants with it out of the body. -by the time the contents of the gi tract reach the end of the small intestine, little remains but water, a few dis- solved salts and body secretions, and undigested materi- als such as fiber. -these enter the large intestine (colon). -in the colon, intestinal bacteria ferment some fibers, producing water, gas, and small fragments of fat that provide energy for the cells of the colon. -the colon itself retrieves all materials that the body can recycle water and dissolved salts (see figure 3-7). -the waste that is fi- nally excreted has little or nothing of value left in it. -the body has extracted all that it can use from the food. -fig- ure 3-8 summarizes digestion by following a sandwich through the gi tract and into the body. -figure 3 8 animated! -the digestive fate of a sandwich to review the digestive processes, follow a peanut butter and banana sandwich on whole-wheat, seasame seed bread through the gi tract. -as the graph on the right illustrates, digestion of the energy nutrients begins in different parts of the gi tract, but all are ready for absorption by the time they reach the end of the small intestine. -digestion, absorption, and transport 79 to test your understanding of these concepts, log on to www .thomsonedu.com/login e t a r d y h o b r a c r e b f i i n e t o r p t a f mouth: chewing and swallowing, with little digestion carbohydrate digestion begins as the salivary enzyme starts to break down the starch from bread and peanut butter. -fiber covering on the sesame seeds is crushed by the teeth, which exposes the nutrients inside the seeds to the upcoming digestive enzymes. -stomach: collecting and churning, with some digestion carbohydrate digestion continues until the mashed sandwich has been mixed with the gastric juices; the stomach acid of the gastric juices inactivates the salivary enzyme, and carbohydrate digestion ceases. -proteins from the bread, seeds, and peanut butter begin to uncoil when they mix with the gastric acid, making them available to the gastric protease enzymes that begin to digest proteins. -fat from the peanut butter forms a separate layer on top of the watery mixture. -small intestine: digesting and absorbing sugars from the banana require so little digestion that they begin to traverse the intestinal cells immediately on contact. -starch digestion picks up when the pancreas sends pancreatic enzymes to the small intestine via the pancreatic duct. -enzymes on the surfaces of the small intestinal cells complete the process of breaking down starch into small fragments that can be absorbed through the intestinal cell walls and into the hepatic portal vein. -fat from the peanut butter and seeds is emulsified with the watery digestive fluids by bile. -now the pancreatic and intestinal lipases can begin to break down the fat to smaller fragments that can be absorbed through the cells of the small intestinal wall and into the lymph. -protein digestion depends on the pancreatic and intestinal proteases. -small fragments of protein are liberated and absorbed through the cells of the small intestinal wall and into the hepatic portal vein. -vitamins and minerals are absorbed. -note: sugars and starches are members of the carbohydrate family. -large intestine: reabsorbing and eliminating fluids and some minerals are absorbed. -some fibers from the seeds, whole-wheat bread, peanut butter, and banana are partly digested by the bacteria living there, and some of these products are absorbed. -most fibers pass through the large intestine and are excreted as feces; some fat, cholesterol, and minerals bind to fiber and are also excreted. -a b s o r p t i o n e x c r e t i o n 80 chapter 3 food must first be digested and absorbed before the body can use it. -villi (vill-ee, vill-eye): fingerlike projections from the folds of the small intestine; singular villus. -microvilli (my-cro-vill-ee, my-cro-vill-eye): tiny, hairlike projections on each cell of every villus that can trap nutrient particles and transport them into the cells; singular microvillus. -crypts (kripts): tubular glands that lie between the intestinal villi and secrete intestinal juices into the small intestine. -goblet cells: cells of the gi tract (and lungs) that secrete mucus. -in summary as figure 3-1 shows, food enters the mouth and travels down the esophagus and through the upper and lower esophageal sphincters to the stomach, then through the pyloric sphincter to the small intestine, on through the ileocecal valve to the large intestine, past the appendix to the rectum, ending at the anus. -the wavelike contractions of peristalsis and the periodic squeezing of segmentation keep things moving at a reasonable pace. -along the way, secre- tions from the salivary glands, stomach, pancreas, liver (via the gallbladder), and small intestine deliver fluids and digestive enzymes. -summary of digestive secretions and their major actions organ or gland target organ secretion action salivary glands mouth saliva gastric glands stomach gastric juice pancreas small intestine pancreatic juice liver gallbladder gallbladder small intestine bile bile intestinal glands small intestine intestinal juice fluid eases swallowing; salivary en- zyme breaks down carbohydrate. -* fluid mixes with bolus; hydrochloric acid uncoils proteins; enzymes break down proteins; mucus protects stomach cells. -* bicarbonate neutralizes acidic gastric juices; pancreatic enzymes break down carbohydrates, fats, and proteins. -bile stored until needed. -bile emulsifies fat so enzymes can attack. -intestinal enzymes break down carbo- hydrate, fat, and protein fragments; mucus protects the intestinal wall. -* saliva and gastric juices also contain lipases, but most fat breakdown occurs in the small intestines. -absorption within three or four hours after you have eaten a dinner of beans and rice (or spinach lasagna, or steak and potatoes) with vegetable, salad, beverage, and dessert, your body must find a way to absorb the molecules derived from carbohy- drate, protein, and fat digestion and the vitamin and mineral molecules as well. -most absorption takes place in the small intestine, one of the most elegantly de- signed organ systems in the body. -within its 10-foot length, which provides a surface area equivalent to a tennis court, the small intestine engulfs and absorbs the nutri- ent molecules. -to remove the molecules rapidly and provide room for more to be ab- sorbed, a rush of circulating blood continuously washes the underside of this surface, carrying the absorbed nutrients away to the liver and other parts of the body. -figure 3-9 describes how nutrients are absorbed by simple diffusion, facilitated diffusion, or active transport. -later chapters provide details on specific nutrients. -before following nutrients through the body, we must look more closely at the anatomy of the absorp- tive system. -s e g a m i y t t e g / n o i t c e l l o c d o o f anatomy of the absorptive system the inner surface of the small intestine looks smooth and slippery, but when viewed through a microscope, it turns out to be wrinkled into hundreds of folds. -each fold is contoured into thousands of fingerlike projections, as numerous as the hairs on vel- vet fabric. -these small intestinal projections are the villi. -a single villus, magnified still more, turns out to be composed of hundreds of cells, each covered with its own microscopic hairs, the microvilli (see figure 3-10 on p. 82). -in the crevices between the villi lie the crypts tubular glands that secrete the intestinal juices into the small intestine. -nearby goblet cells secrete mucus. -figure 3 9 absorption of nutrients absorption of nutrients into intestinal cells typically occurs by simple diffusion, facilitated diffusion, or active transport. -digestion, absorption, and transport 81 outside cell cell membrane inside cell carrier loads nutrient on outside of cell . -. -. -carrier loads nutrient on outside of cell . -. -. -energy . -. -. -and then releases it on inside of cell. -. -. -. -and then releases it on inside of cell. -simple diffusion facilitated diffusion active transport some nutrients (such as water and small lipids) are absorbed by simple diffusion. -they cross into intestinal cells freely. -some nutrients (such as the water-soluble vitamins) are absorbed by facilitated diffusion. -they need a specific carrier to transport them from one side of the cell membrane to the other. -(alternatively, facilitated diffusion may occur when the carrier changes the cell membrane in such a way that the nutrients can pass through.) -some nutrients (such as glucose and amino acids) must be absorbed actively. -these nutrients move against a concentration gradient, which requires energy. -the villi are in constant motion. -each villus is lined by a thin sheet of muscle, so it can wave, squirm, and wriggle like the tentacles of a sea anemone. -any nutrient molecule small enough to be absorbed is trapped among the microvilli that coat the cells and then drawn into the cells. -some partially digested nutrients are caught in the microvilli, digested further by enzymes there, and then absorbed into the cells. -a closer look at the intestinal cells the cells of the villi are among the most amazing in the body, for they recognize and select the nutrients the body needs and regulate their absorption. -as already de- scribed, each cell of a villus is coated with thousands of microvilli, which project from the cell s membrane (review figure 3-10). -in these microvilli, and in the mem- brane, lie hundreds of different kinds of enzymes and pumps, which recognize and act on different nutrients. -descriptions of specific enzymes and pumps for each nutrient are presented in the following chapters where appropriate; the point here is that the cells are equipped to handle all kinds and combinations of foods and nutrients. -specialization in the gi tract a further refinement of the system is that the cells of successive portions of the intestinal tract are specialized to absorb different nutri- ents. -the nutrients that are ready for absorption early are absorbed near the top of the tract; those that take longer to be digested are absorbed farther down. -registered dietitians and medical professionals who treat digestive disorders learn the special- ized absorptive functions of different parts of the gi tract so that if one part becomes dysfunctional, the diet can be adjusted accordingly. -the myth of food combining the idea that people should not eat certain food combinations (for example, fruit and meat) at the same meal, because the di- gestive system cannot handle more than one task at a time, is a myth. -the art of food combining (which actually emphasizes food separating ) is based on this idea, and it represents faulty logic and a gross underestimation of the body s capa- bilities. -in fact, the contrary is often true; foods eaten together can enhance each the problem of food contaminants, which may be absorbed defenselessly by the body, is the subject of chapter 19. -82 chapter 3 figure 3 10 the small intestinal villi absorption of nutrients into intestinal cells typically occurs by simple diffusion or active transport. -stomach small intestine folds with villi on them the wall of the small intestine is wrinkled into thousands of folds and is carpeted with villi. -microvilli circular muscles longitudinal muscles this is a photograph of part of an actual human intestinal cell with microvilli. -t t e c w a f . -w n o d each villus in turn is covered with even smaller projections, the microvilli. -microvilli on the cells of villi provide the absorptive surfaces that allow the nutrients to pass through to the body. -capillaries a villus goblet cells crypts artery vein lymphatic vessel k c o t s r e p u s w e r c / l l i b if you have ever watched a sea anemone with its fingerlike projections in constant motion, you have a good picture of how the intestinal villi move. -lymphatic vessel (lacteal) other s use by the body. -for example, vitamin c in a pineapple or other citrus fruit can enhance the absorption of iron from a meal of chicken and rice or other iron- containing foods. -many other instances of mutually beneficial interactions are pre- sented in later chapters. -preparing nutrients for transport when a nutrient molecule has crossed the cell of a villus, it enters either the bloodstream or the lymphatic system. -both trans- port systems supply vessels to each villus, as shown in figure 3-10. the water-soluble digestion, absorption, and transport 83 nutrients and the smaller products of fat digestion are released directly into the bloodstream and guided directly to the liver where their fate and destination will be determined. -the larger fats and the fat-soluble vitamins are insoluble in water, however, and blood is mostly water. -the intestinal cells assemble many of the products of fat di- gestion into larger molecules. -these larger molecules cluster together with special proteins, forming chylomicrons. -because these chylomicrons cannot pass into the capillaries, they are released into the lymphatic system instead; the chylomi- crons move through the lymph and later enter the bloodstream at a point near the heart, thus bypassing the liver at first. -details follow. -in summary the many folds and villi of the small intestine dramatically increase its sur- face area, facilitating nutrient absorption. -nutrients pass through the cells of the villi and enter either the blood (if they are water soluble or small fat frag- ments) or the lymph (if they are fat soluble). -the circulatory systems once a nutrient has entered the bloodstream, it may be transported to any of the cells in the body, from the tips of the toes to the roots of the hair. -the circulatory sys- tems deliver nutrients wherever they are needed. -the vascular system the vascular, or blood circulatory, system is a closed system of vessels through which blood flows continuously, with the heart serving as the pump (see figure 3-11, p. 84). -as the blood circulates through this system, it picks up and delivers materials as needed. -all the body tissues derive oxygen and nutrients from the blood and deposit car- bon dioxide and other wastes back into the blood. -the lungs exchange carbon dioxide (which leaves the blood to be exhaled) and oxygen (which enters the blood to be delivered to all cells). -the digestive system supplies the nutrients to be picked up. -in the kidneys, wastes other than carbon dioxide are filtered out of the blood to be excreted in the urine. -blood leaving the right side of the heart circulates through the lungs and then back to the left side of the heart. -the left side of the heart then pumps the blood out of the aorta through arteries to all systems of the body. -the blood circulates in the capil- laries, where it exchanges material with the cells and then collects into veins, which return it again to the right side of the heart. -in short, blood travels this simple route: heart to arteries to capillaries to veins to heart the routing of the blood leaving the digestive system has a special feature. -the blood is carried to the digestive system (as to all organs) by way of an artery, which (as in all organs) branches into capillaries to reach every cell. -blood leaving the di- gestive system, however, goes by way of a vein. -the hepatic portal vein directs blood not back to the heart, but to another organ the liver. -this vein again branches into capillaries so that every cell of the liver has access to the blood. -blood leaving the liver then again collects into a vein, called the hepatic vein, which re- turns blood to the heart. -the route is: heart to arteries to capillaries (in intestines) to hepatic portal vein to capil- laries (in liver) to hepatic vein to heart chylomicrons (kye-lo-my-cronz) are described in chapter 5. aorta (ay-or-tuh): the large, primary artery that conducts blood from the heart to the body s smaller arteries. -arteries: vessels that carry blood from the heart to the tissues. -capillaries (cap-ill-aries): small vessels that branch from an artery. -capillaries connect arteries to veins. -exchange of oxygen, nutrients, and waste materials takes place across capillary walls. -veins (vanes): vessels that carry blood to the heart. -hepatic portal vein: the vein that collects blood from the gi tract and conducts it to capillaries in the liver. -portal = gateway hepatic vein: the vein that collects blood from the liver capillaries and returns it to the heart. -hepatic = liver 84 chapter 3 figure 3 11 animated! -the vascular system to test your understanding of these concepts, log on to www .thomsonedu.com/login pulmonary artery 1 7 blood leaves the right side of the heart by way of the pulmonary artery. -lymph from most of the body s organs, including the digestive system, enters the bloodstream near the heart. -7 right side hepatic vein liver 6 blood returns to the right side of the heart. -6 lymph entire body key: arteries capillaries veins lymph vessels head and upper body lungs 2 3 aorta 1 4 left side 2 3 blood loses carbon dioxide and picks up oxygen in the lungs and r returns to the left side of the heart by way of the pulmonary vein. -pulmonary vein blood leaves the left side of the heart by way of the aorta, the main artery that launches blood on its course through the body. -4 blood may leave the aorta to go to the upper body and head; heart or hepatic artery hepatic portal vein digestive tract 5 blood may leave the aorta to go to the lower body. -5 blood may go to the digestive tract and then the liver; or blood may go to the pelvis, kidneys, and legs. -figure 3-12 shows the liver s key position in nutrient transport. -an anatomist studying this system knows there must be a reason for this special arrangement. -the liver s placement ensures that it will be first to receive the nutrients absorbed from the gi tract. -in fact, the liver has many jobs to do in preparing the absorbed nutrients for use by the body. -it is the body s major metabolic organ. -you might guess that, in addition, the liver serves as a gatekeeper to defend against substances that might harm the heart or brain. -this is why, when people ingest poisons that succeed in passing the first barrier (the intestinal cells), the liver quite often suffers the damage from viruses such as hepatitis, from drugs such as barbiturates or alcohol, from toxins such as pesticide residues, and from contami- nants such as mercury. -perhaps, in fact, you have been undervaluing your liver, not knowing what heroic tasks it quietly performs for you. -lymphatic (lim-fat-ic) system: a loosely organized system of vessels and ducts that convey fluids toward the heart. -the gi part of the lymphatic system carries the products of fat digestion into the bloodstream. -the lymphatic system the lymphatic system provides a one-way route for fluid from the tissue spaces to enter the blood. -unlike the vascular system, the lymphatic system has figure 3 12 the liver digestion, absorption, and transport 85 hepatic artery hepatic portal vein 1 2 3 4 5 vessels gather up nutrients and reabsorbed water and salts from all over the digestive tract. -not shown here: parallel to these vessels (veins) are other vessels (arteries) that carry oxygen-rich blood from the heart to the intestines. -the vessels merge into the hepatic portal vein, which conducts all absorbed materials to the liver. -the hepatic artery brings a supply of freshly oxygenated blood (not loaded with nutrients) from the lungs to supply oxygen to the liver s own cells. -capillaries branch all over the liver, making nutrients and oxygen available to all its cells and giving the cells access to blood from the digestive system. -the hepatic vein gathers up blood in the liver and returns it to the heart. -in contrast, nutrients absorbed into lymph do not go to the liver first. -they go to the heart, which pumps them to all the body s cells. -the cells remove the nutrients they need, and the liver then has to deal only with the remnants. -hepatic vein capillaries 4 5 3 2 vessels 1 no pump; instead, lymph circulates between the cells of the body and collects into tiny vessels. -the fluid moves from one portion of the body to another as muscles contract and create pressure here and there. -ultimately, much of the lymph collects in the thoracic duct behind the heart. -the thoracic duct opens into the subclavian vein, where the lymph enters the bloodstream. -thus nu- trients from the gi tract that enter lymphatic vessels (large fats and fat-solu- ble vitamins) ultimately enter the bloodstream, circulating through arteries, capillaries, and veins like the other nutrients, with a notable exception they bypass the liver at first. -once inside the vascular system, the nutrients can travel freely to any destina- tion and can be taken into cells and used as needed. -what becomes of them is de- scribed in later chapters. -in summary nutrients leaving the digestive system via the blood are routed directly to the liver before being transported to the body s cells. -those leaving via the lym- phatic system eventually enter the vascular system but bypass the liver at first. -the lymphatic vessels of the intestine that take up nutrients and pass them to the lymph circulation are called lacteals (lack-tee-als). -lymph (limf): a clear yellowish fluid that is similar to blood except that it contains no red blood cells or platelets. -lymph from the gi tract transports fat and fat-soluble vitamins to the bloodstream via lymphatic vessels. -thoracic (thor-ass-ic) duct: the main lymphatic vessel that collects lymph and drains into the left subclavian vein. -subclavian (sub-klay-vee-an) vein: the vein that provides passageway from the lymphatic system to the vascular system. -86 chapter 3 factors influencing gi function: physical immaturity aging illness nutrition bacteria in the intestines are sometimes re- ferred to as flora or microflora. -food components (such as fibers) that are not digested in the small intestine, but are used instead as food by bacteria to encour- age their growth are called prebiotics. -vitamins produced by bacteria include: biotin folate vitamin b6 vitamin b12 vitamin k yogurt: milk product that results from the fermentation of lactic acid in milk by lactobacillus bulgaricus and streptococcus thermophilus. -probiotics: living microorganisms found in foods that, when consumed in sufficient quantities, are beneficial to health. -pro = for bios = life homeostasis (home-ee-oh-stay-sis): the maintenance of constant internal conditions (such as blood chemistry, temperature, and blood pressure) by the body s control systems. -a homeostatic system is constantly reacting to external forces to maintain limits set by the body s needs. -homeo = the same stasis = staying the health and regulation of the gi tract this section describes the bacterial conditions and hormonal regulation of a healthy gi tract, but many factors can influence normal gi function. -for example, peri- stalsis and sphincter action are poorly coordinated in newborns, so infants tend to spit up during the first several months of life. -older adults often experience consti- pation, in part because the intestinal wall loses strength and elasticity with age, which slows gi motility. -diseases can also interfere with digestion and absorption and often lead to malnutrition. -lack of nourishment, in general, and lack of certain dietary constituents such as fiber, in particular, alter the structure and function of gi cells. -quite simply, gi tract health depends on adequate nutrition. -gastrointestinal bacteria an estimated 10 trillion bacteria representing some 400 or more different species and subspecies live in a healthy gi tract. -the prevalence of different bacteria in var- ious parts of the gi tract depends on such factors as ph, peristalsis, diet, and other microorganisms. -relatively few microorganisms can live in the low ph of the stom- ach with its relatively rapid peristalsis, whereas the neutral ph and slow peristalsis of the lower small intestine and the large intestine permit the growth of a diverse and abundant bacterial population.1 most of these bacteria normally do the body no harm and may actually do some good. -provided that the normal intestinal flora are thriving, infectious bacteria have a hard time establishing themselves to launch an attack on the system. -diet is one of several factors that influence the body s bacterial population and environment. -consider yogurt, for example.2 yogurt contains lactobacillus and other living bacteria. -these microorganisms are considered probiotics because they change the conditions and native bacterial colonies in the gi tract in ways that seem to benefit health.3 the potential gi health benefits of probiotics include helping to alleviate diarrhea, constipation, inflammatory bowel disease, ulcers, al- lergies, and lactose intolerance; enhance immune function; and protect against colon cancer.4 some probiotics may have adverse effects under certain circum- stances.5 research studies continue to explore how diet influences gi bacteria and which foods with their probiotics affect gi health. -gi bacteria also digest fibers and complex proteins.6 in doing so, the bacteria produce nutrients such as short fragments of fat that the cells of the colon use for energy. -bacteria in the gi tract also produce several vitamins, including a signif- icant amount of vitamin k, although the amount is insufficient to meet the body s total need for that vitamin. -gastrointestinal hormones and nerve pathways the ability of the digestive tract to handle its ever-changing contents routinely il- lustrates an important physiological principle that governs the way all living things function the principle of homeostasis. -simply stated, survival depends on body conditions staying about the same; if they deviate too far from the norm, the body must do something to bring them back to normal. -the body s regula- tion of digestion is one example of homeostatic regulation. -the body also regu- lates its temperature, its blood pressure, and all other aspects of its blood chemistry in similar ways. -two intricate and sensitive systems coordinate all the digestive and absorptive processes: the hormonal (or endocrine) system and the nervous system. -even be- fore the first bite of food is taken, the mere thought, sight, or smell of food can trig- digestion, absorption, and transport 87 ger a response from these systems. -then, as food travels through the gi tract, it ei- ther stimulates or inhibits digestive secretions by way of messages that are carried from one section of the gi tract to another by both hormones and nerve path- ways. -(appendix a presents a brief summary of the body s hormonal system and nervous system.) -notice that the kinds of regulation described next are all examples of feedback mechanisms. -a certain condition demands a response. -the response changes that condition, and the change then cuts off the response. -thus the system is self-correct- ing. -examples follow: the stomach normally maintains a ph between 1.5 and 1.7. how does it stay that way? -food entering the stomach stimulates cells in the stomach wall to re- lease the hormone gastrin. -gastrin, in turn, stimulates the stomach glands to secrete the components of hydrochloric acid. -when ph 1.5 is reached, the acid itself turns off the gastrin-producing cells. -they stop releasing gastrin, and the glands stop producing hydrochloric acid. -thus the system adjusts itself. -nerve receptors in the stomach wall also respond to the presence of food and stimulate the gastric glands to secrete juices and the muscles to contract. -as the stomach empties, the receptors are no longer stimulated, the flow of juices slows, and the stomach quiets down. -the pyloric sphincter opens to let out a little chyme, then closes again. -how does it know when to open and close? -when the pyloric sphincter relaxes, acidic chyme slips through. -the cells of the pyloric muscle on the intestinal side sense the acid, causing the pyloric sphincter to close tightly. -only after the chyme has been neutralized by pancreatic bicarbonate and the juices sur- rounding the pyloric sphincter have become alkaline can the muscle relax again. -this process ensures that the chyme will be released slowly enough to be neutralized as it flows through the small intestine. -this is important be- cause the small intestine has less of a mucous coating than the stomach does and so is not as well protected from acid. -as the chyme enters the intestine, the pancreas adds bicarbonate to it so that the intestinal contents always remain at a slightly alkaline ph. -how does the pancreas know how much to add? -the presence of chyme stimulates the cells of the duodenum wall to release the hormone secretin into the blood. -when se- cretin reaches the pancreas, it stimulates the pancreas to release its bicarbon- ate-rich juices. -thus, whenever the duodenum signals that acidic chyme is present, the pancreas responds by sending bicarbonate to neutralize it. -when the need has been met, the cells of the duodenum wall are no longer stimulated to release secretin, the hormone no longer flows through the blood, the pancreas no longer receives the message, and it stops sending pancreatic juice. -nerves also regulate pancreatic secretions. -pancreatic secretions contain a mixture of enzymes to digest carbohydrate, fat, and protein. -how does the pancreas know how much of each type of enzyme to provide? -this is one of the most interesting questions physiologists have asked. -clearly, the pancreas does know what its owner has been eating, and it se- cretes enzyme mixtures tailored to handle the food mixtures that have been arriving recently (over the last several days). -enzyme activity changes pro- portionately in response to the amounts of carbohydrate, fat, and protein in the diet. -if a person has been eating mostly carbohydrates, the pancreas makes and secretes mostly carbohydrases; if the person s diet has been high in fat, the pancreas produces more lipases; and so forth. -presumably, hor- mones from the gi tract, secreted in response to meals, keep the pancreas in- formed as to its digestive tasks. -the day or two lag between the time a person s diet changes dramatically and the time digestion of the new diet be- comes efficient explains why dietary changes can upset digestion and should be made gradually. -in general, any gastrointestinal hormone may be called an enterogastrone (en-ter- oh-gas-trone), but the term refers specifically to any hormone that slows motility and inhibits gastric secretions. -hormones: chemical messengers. -hormones are secreted by a variety of glands in response to altered conditions in the body. -each hormone travels to one or more specific target tissues or organs, where it elicits a specific response to maintain homeostasis. -gastrin: a hormone secreted by cells in the stomach wall. -target organ: the glands of the stomach. -response: secretion of gastric acid. -secretin (see-creet-in): a hormone produced by cells in the duodenum wall. -target organ: the pancreas. -response: secretion of bicarbonate-rich pancreatic juice. -88 chapter 3 the inactive precursor of an enzyme is called a proenzyme or zymogen (zye-mo-jen). -pro = before zym = concerning enzymes gen = to produce why don t the digestive enzymes damage the pancreas? -the pancreas protects it- self from harm by producing an inactive form of the enzymes. -it releases these proteins into the small intestine where they are activated to become enzymes. -in pancreatitis, the digestive enzymes become active within the in- fected pancreas, causing inflammation and damaging the delicate pancreatic tissues. -when fat is present in the intestine, the gallbladder contracts to squirt bile into the intestine to emulsify the fat. -how does the gallbladder get the message that fat is present? -fat in the intestine stimulates cells of the intestinal wall to release the hormone cholecystokinin (cck). -this hormone, traveling by way of the blood to the gallbladder, stimulates it to contract, releasing bile into the small intestine. -cholescystokinin also travels to the pancreas, stimulates it to secrete its juices, releasing bicarbonate and enzymes into the small intestine. -once the fat in the intestine is emulsified and enzymes have begun to work on it, the fat no longer provokes release of the hormone, and the message to contract is canceled. -(by the way, fat emulsification can continue even after a diseased gallbladder has been surgically removed because the liver can de- liver bile directly to the small intestine.) -fat and protein take longer to digest than carbohydrate does. -when fat or protein is present, intestinal motility slows to allow time for its digestion. -how does the intes- tine know when to slow down? -cholecystokinin is released in response to fat or protein in the small intestine. -in addition to its role in fat emulsification and digestion, cholecystokinin slows gi tract motility. -slowing the digestive process helps to maintain a pace that allows all reactions to reach completion. -hormonal and nervous mechanisms like these account for much of the body s ability to adapt to changing conditions. -table 3-1 summarizes the actions of these gi hormones. -once a person has started to learn the answers to questions like these, it may be hard to stop. -some people devote their whole lives to the study of physiology. -for now, however, these few examples illustrate how all the processes throughout the digestive system are precisely and automatically regulated without any conscious effort. -in summary a diverse and abundant bacteria population support gi health. -the regula- tion of gi processes depends on the coordinated efforts of the hormonal system and the nervous system; together, digestion and absorption transform foods into nutrients. -cholecystokinin (coal-ee-sis-toe-kine-in), or cck: a hormone produced by cells of the intestinal wall. -target organ: the gallbladder. -response: release of bile and slowing of gi motility. -the system at its best this chapter describes the anatomy of the digestive tract on several levels: the se- quence of digestive organs, the cells and structures of the villi, and the selective ma- table 3-1 the primary actions of gi hormones hormone: responds to: secreted from: stimulates: response: gastrin secretin acidic chyme in the small intestine duodenal wall pancreas food in the stomach stomach wall stomach glands hydrochloric acid secreted into the stomach cholecystokinin fat or protein in the small intestine intestinal wall gallbladder pancreas bicarbonate-rich juices secreted into the small intestine bile secreted into the duodenum bicarbonate- and enzyme-rich juices secreted into the small intestine digestion, absorption, and transport 89 chinery of the cell membranes. -the intricate architec- ture of the digestive system makes it sensitive and re- sponsive to conditions in its environment. -several different kinds of gi tract cells confer specific immunity against intestinal diseases such as inflammatory bowel disease. -in addition, secretions from the gi tract saliva, mucus, gastric acid, and digestive enzymes not only help with digestion, but also defend against for- eign invaders. -together the gi s team of bacteria, cells, and secretions defend the body against numerous chal- lenges.7 knowing the optimal conditions will help you to make choices that promote the best functioning of the system. -one indispensable condition is good health of the digestive tract itself. -this health is affected by such lifestyle factors as sleep, physical activity, and state of mind. -adequate sleep allows for repair and mainte- nance of tissue and removal of wastes that might im- pair efficient functioning. -activity promotes healthy muscle tone. -mental state influences the activity of regulatory nerves and hor- mones; for healthy digestion, you should be relaxed and tranquil at mealtimes. -another factor in gi health is the kind of meals you eat. -among the character- istics of meals that promote optimal absorption of nutrients are those mentioned in chapter 2: balance, moderation, variety, and adequacy. -balance and modera- tion require having neither too much nor too little of anything. -for example, too much fat can be harmful, but some fat is beneficial in slowing down intestinal motility and providing time for absorption of some of the nutrients that are slow to be absorbed. -variety is important for many reasons, but one is that some food constituents in- terfere with nutrient absorption. -for example, some compounds common in high- fiber foods such as whole-grain cereals, certain leafy green vegetables, and legumes bind with minerals. -to some extent, then, the minerals in those foods may become unavailable for absorption. -these high-fiber foods are still valuable, but they need to be balanced with a variety of other foods that can provide the minerals. -as for adequacy in a sense, this entire book is about dietary adequacy. -but here, at the end of this chapter, is a good place to underline the interdependence of the nutrients. -it could almost be said that every nutrient depends on every other. -all the nutrients work together, and all are present in the cells of a healthy diges- tive tract. -to maintain health and promote the functions of the gi tract, you should make balance, moderation, variety, and adequacy features of every day s menus. -s e g a m i y t t e g / s n o i t c u d o r p a j a nourishing foods and pleasant conversations support a healthy digestive system. -nutrition portfolio www.thomsonedu.com/login a healthy digestive system can adjust to almost any diet and can handle any combina- tion of foods with ease. -describe the physical and emotional environment that typically surrounds your meals, including how it affects you and how it might be improved. -detail any gi discomforts you may experience regularly and include suggestions to alleviate or prevent their occurrence (see highlight 3). -list any changes you can make in your eating habits to promote overall gi health. -90 chapter 3 nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 3, then to nutrition on the net. -visit the center for digestive health and nutrition: www.gihealth.com study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review this chapter. -you will find the answers in the discussions on the pages provided. -1. describe the challenges associated with digesting food and the solutions offered by the human body. -(pp. -71 80) 2. describe the path food follows as it travels through the digestive system. -summarize the muscular actions that take place along the way. -(pp. -72 76) 3. name five organs that secrete digestive juices. -how do the juices and enzymes facilitate digestion? -(pp. -76 78) 4. describe the problems associated with absorbing nutri- ents and the solutions offered by the small intestine. -(pp. -80 83) 5. how is blood routed through the digestive system? -which nutrients enter the bloodstream directly? -which are first absorbed into the lymph? -(pp. -83 85) 6. describe how the body coordinates and regulates the processes of digestion and absorption. -(pp. -86 88) 7. how does the composition of the diet influence the functioning of the gi tract? -(p. 89) 8. what steps can you take to help your gi tract function at its best? -(p. 89) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 91. -1. the semiliquid, partially digested food that travels through the intestinal tract is called: a. bile. -b. lymph. -c. chyme. -d. secretin. -2. the muscular contractions that move food through the gi tract are called: a. hydrolysis. -b. sphincters. -c. peristalsis. -d. bowel movements. -3. the main function of bile is to: a. emulsify fats. -visit the patient information section of the american college of gastroenterology: www.acg.gi.org b. catalyze hydrolysis. -c. slow protein digestion. -d. neutralize stomach acidity. -4. the pancreas neutralizes stomach acid in the small intes- tine by secreting: a. bile. -b. mucus. -c. enzymes. -d. bicarbonate. -5. which nutrient passes through the gi tract mostly undi- gested and unabsorbed? -a. fat b. fiber c. protein d. carbohydrate 6. absorption occurs primarily in the: a. mouth. -b. stomach. -c. small intestine. -d. large intestine. -7. all blood leaving the gi tract travels first to the: a. heart. -b. liver. -c. kidneys. -d. pancreas. -8. which nutrients leave the gi tract by way of the lymphatic system? -a. water and minerals b. proteins and minerals c. all vitamins and minerals d. fats and fat-soluble vitamins 9. digestion and absorption are coordinated by the: a. pancreas and kidneys. -b. liver and gallbladder. -c. hormonal system and the nervous system. -d. vascular system and the lymphatic system. -10. gastrin, secretin, and cholecystokinin are examples of: a. crypts. -b. enzymes. -c. hormones. -d. goblet cells. -digestion, absorption, and transport 91 references 1. p. b. eckburg and coauthors, diversity of the human intestinal microbial flora, science 308 (2005): 1635-1638; w. l. hao and y. k. lee, microflora of the gastrointestinal tract: a review, methods in molecular biology 268 (2004): 491-502. -2. o. adolfsson, s. n. meydani, and r. m. russell, yogurt and gut function, american journal of clinical nutrition 80 (2004): 245-256. -3. c. c. chen and w. a. walker, probiotics and prebiotics: role in clinical disease states, advances in pediatrics 52 (2005): 77-113; m. e. sanders, probiotics: considerations for human health, nutrition reviews 61 (2003): 91-99; m. h. floch and j. hong-curtiss, probiotics and functional foods in gastroin- testinal disorders, current gastroenterology reports 3 (2001): 343-350; probiotics and prebiotics, american journal of clinical nutri- tion (supp.) -73 (2001): entire issue. -4. s. santosa, e. farnworth, p. j. h. jones, probiotics and their potential health claims, nutrition reviews 64 (2006): 265-274; s. j. salminen, m. gueimonde, and e. isolauri, probiotics that modify disease risk, american society for nutritional sciences 135 (2005): 1294-1298; f. guarner and coauthors, should yoghurt cultures be considered probiotic? -british journal of nutrition 93 (2005): 783-786; j. m. saavedra and a. tschernia, human studies with probiotics and prebiotics: clinical implications, british journal of nutrition 87 (2002): s241-s246; p. marteau and m. c. boutron-ruault, nutri- tional advantages of probiotics and prebi- otics, british journal of nutrition 87 (2002): s153-s157; g. t. macfarlane and j. h. cum- mings, probiotics, infection and immunity, current opinion in infectious diseases 15 (2002): 501-506; l. kopp-hoolihan, prophy- lactic and therapeutic uses of probiotics: a review, journal of the american dietetic associ- ation 101 (2001): 229-238; m. b. roberfroid, prebiotics and probiotics: are they func- tional foods? -american journal of clinical nutrition 71 (2000): 1682s-1687s. -5. j. ezendam and h. van loveren, probiotics: immunomodulation and evaluation of safety and efficacy, nutrition reviews 64 (2006): 1-14. -6. j. m. wong and coauthors, colonic health: fermentation and short chain fatty acids, journal of clinical gastroenterology 40 (2006): 235-243; s. bengmark, colonic food: pre- and probiotics, american journal of gastroen- terology 95 (2000): s5-s7. -7. p. bourlioux and coauthors, the intestine and its microflora are partners for the pro- tection of the host: report on the danone symposium the intelligent intestine, held in paris, june 14, 2002, american journal of clinical nutrition 78 (2003): 675-683. answers study questions (multiple choice) 1. c 9. c 2. c 3. a 4. d 5. b 6. c 7. b 8. d 10. c highlight 3 common digestive problems the facts of anatomy and physiology pre- sented in chapter 3 permit easy understand- ing of some common problems that occasionally arise in the digestive tract. -food may slip into the air passages instead of the esophagus, causing choking. -bowel move- ments may be loose and watery, as in diar- rhea, or painful and hard, as in constipation. -some people complain about belching, while others are bothered by intestinal gas. -sometimes people develop medical problems such as an ulcer. -this highlight describes some of the symptoms of these common digestive problems and suggests strategies for preventing them (the glossary on p. 94 defines the relevant terms). -choking a person chokes when a piece of food slips into the trachea and becomes lodged so securely that it cuts off breathing (see figure h3-1). -without oxygen, the person may suffer brain damage or die. -for this reason, it is imperative that everyone learns to recog- nize a person grabbing his or her own throat as the international signal for choking (shown in figure h3-2) and act promptly. -figure h3-1 normal swallowing and choking tongue food larynx rises epiglottis closes over larynx esophagus (to stomach) trachea (to lungs) the choking scenario might read like this. -a person is dining in a restaurant with friends. -a chunk of food, usually meat, becomes lodged in his trachea so firmly that he cannot make a sound. -no sound can be made be- cause the larynx is in the trachea and makes sounds only when air is pushed across it. -of- ten he chooses to suffer alone rather than make a scene in public. -if he tries to communicate distress to his friends, he must depend on pantomime. -the friends are bewil- dered by his antics and become terribly worried when he faints after a few minutes without air. -they call for an ambulance, but by the time it arrives, he is dead from suffocation. -s i b r o c to help a person who is choking, first ask this critical question: can you make any sound at all? -if so, relax. -you have time to decide what you can do to help. -whatever you do, do not hit him on the back the particle may become lodged more firmly in his air passage. -if the person cannot make a sound, shout for help and perform the heimlich maneuver (described in figure h3- 2). -you would do well to take a life-saving course and practice these techniques because you will have no time for hesitation if you are called upon to perform this death-defying act. -almost any food can cause choking, although some are cited more often than others: chunks of meat, hot dogs, nuts, whole grapes, raw carrots, marshmallows, hard or sticky candies, gum, popcorn, and peanut but- ter. -these foods are particularly difficult for young children to safely chew and swallow. -in 2000, more than 17,500 children (under 15 years old) in the united states choked; most of them choked on food, and 160 of them choked to death.1 always remain alert to the dangers of choking whenever young children are eating. -to prevent choking, cut food into small pieces, chew thoroughly before swallowing, don t talk or laugh with food in your mouth, and don t eat when breathing hard. -vomiting another common digestive mishap is vomiting. -vomiting can be a symptom of many different diseases or may arise in situations that upset the body s equilibrium, such as air or sea travel. -for whatever reason, the contents of the stomach are propelled up through the esophagus to the mouth and expelled. -swallowing. -the epiglottis closes over the larynx, blocking entrance to the lungs via the trachea. -the red arrow shows that food is heading down the esophagus normally. -choking. -a choking person cannot speak or gasp because food lodged in the trachea blocks the passage of air. -the red arrow points to where the food should have gone to prevent choking. -92 figure h3-2 first aid for choking the first-aid strategy most likely to succeed is abdominal thrusts, sometimes called the heimlich maneuver. -only if all else fails, open the person s mouth by grasping both his tongue and lower jaw and lifting. -then, and only if you can see the object, use your finger to sweep it out and begin rescue breathing. -common digestive problems 93 self-induced vomiting, such as occurs in bulimia nervosa, also has serious conse- quences. -in addition to fluid and salt imbal- ances, repeated vomiting can cause irritation and infection of the pharynx, esophagus, and salivary glands; erosion of the teeth and gums; and dental caries. -the esophagus may rupture or tear, as may the stomach. -sometimes the eyes become red from pressure during vomiting. -bulimic be- havior reflects underlying psychological problems that require intervention. -(bulimia nervosa is discussed fully in highlight 8.) -projectile vomiting is also serious. -the contents of the stomach are expelled with such force that they leave the mouth in a wide arc like a bullet leaving a gun. -this type of vomiting requires immediate med- ical attention. -diarrhea diarrhea is characterized by frequent, loose, watery stools. -such stools indicate that the intestinal contents have moved too quickly through the intestines for fluid absorption to take place, or that water has been drawn from the cells lining the intes- tinal tract and added to the food residue. -like vomiting, diarrhea can lead to consid- erable fluid and salt losses, but the compo- sition of the fluids is different. -stomach fluids lost in vomiting are highly acidic, whereas intestinal fluids lost in diarrhea are nearly neutral. -when fluid losses require medical attention, correct re- placement is crucial. -diarrhea is a symptom of various medical conditions and treat- ments. -it may occur abruptly in a healthy person as a result of in- fections (such as food poisoning) or as a side effect of medications. -when used in large quantities, food ingredients such as the sugar alternative sorbitol and the fat alternative olestra may also cause diarrhea in some people. -if a food is re- sponsible, then that food must be omitted from the diet, at least temporarily. -if medication is responsible, a different medicine, when possible, or a different form (injectable versus oral, for ex- ample) may alleviate the problem. -diarrhea may also occur as a result of disorders of the gi tract, such as irritable bowel syndrome or colitis. -irritable bowel syn- drome is one of the most common gi disorders and is character- ized by a disturbance in the motility of the gi tract.2 in most cases, gi contractions are stronger and last longer than normal, forcing intestinal contents through quickly and causing gas, bloating, and diarrhea. -in some cases, however, gi contractions are weaker than normal, slowing the passage of intestinal con- tents and causing constipation. -the exact cause of irritable bowel syndrome is not known, but researchers believe nerves and hor- mones are involved. -the condition seems to worsen for some the universal signal for choking is when a person grabs his throat. -it alerts others to the need for assistance. -if this happens, stand behind the person, and wrap your arms around him. -place the thumb side of one fist snugly against his body, slightly above the navel and below the rib cage. -grasp your fist with your other hand and give him a sudden strong hug inward and upward. -repeat thrusts as necessary. -if you are choking and need to self-administer first aid, place the thumb side of one fist slightly above your navel and below your rib cage, grasp the fist with your other hand, and then press inward and upward with a quick motion. -if this is unsuccessful, quickly press your upper abdomen over any firm surface such as the back of a chair, a countertop, or a railing. -if vomiting continues long enough or is severe enough, the muscular contractions will extend beyond the stomach and carry the contents of the duodenum, with its green bile, into the stom- ach and then up the esophagus. -although certainly unpleasant and wearying for the nauseated person, vomiting such as this is no cause for alarm. -vomiting is one of the body s adaptive mech- anisms to rid itself of something irritating. -the best advice is to rest and drink small amounts of liquids as tolerated until the nau- sea subsides. -a physician s care may be needed, however, when large quan- tities of fluid are lost from the gi tract, causing dehydration. -with massive fluid loss from the gi tract, all of the body s other fluids redistribute themselves so that, eventually, fluid is taken from every cell of the body. -leaving the cells with the fluid are salts that are absolutely essential to the life of the cells, and they must be re- placed. -replacement is difficult if the vomiting continues, and in- travenous feedings of saline and glucose may be necessary while the physician diagnoses the cause of the vomiting and begins corrective therapy. -in an infant, vomiting is likely to become serious early in its course, and a physician should be contacted soon after onset. -in- fants have more fluid between their body cells than adults do, so more fluid can move readily into the digestive tract and be lost from the body. -consequently, the body water of infants becomes depleted and their body salt balance upset faster than in adults. -94 highlight 3 g lossary acid controllers: medications used to prevent or relieve indigestion by suppressing production of acid in the stomach; also called h2 blockers. -common brands include pepcid ac, tagamet hb, zantac 75, and axid ar. -antacids: medications used to relieve indigestion by neutralizing acid in the stomach. -common brands include alka-seltzer, maalox, rolaids, and tums. -belching: the expulsion of gas from the stomach through the mouth. -colitis (ko-lye-tis): inflammation of the colon. -diverticula (dye-ver-tic-you-la): sacs or pouches that develop in the weakened areas of the intestinal wall (like bulges in an inner tube where the tire wall is weak). -divertir (cid:2) to turn aside diverticulitis (dye-ver-tic-you- lye-tis): infected or inflamed diverticula. -itis (cid:2) infection or inflammation diverticulosis (dye-ver-tic-you- loh-sis): the condition of having diverticula. -about one in every six people in western countries develops diverticulosis in middle or later life. -osis (cid:2) condition colonic irrigation: the popular, enemas: solutions inserted into but potentially harmful practice of washing the large intestine with a powerful enema machine. -the rectum and colon to stimulate a bowel movement and empty the lower large intestine. -constipation: the condition of having infrequent or difficult bowel movements. -defecate (def-uh-cate): to move the bowels and eliminate waste. -defaecare (cid:2) to remove dregs diarrhea: the frequent passage of watery bowel movements. -gastroesophageal reflux: the backflow of stomach acid into the esophagus, causing damage to the cells of the esophagus and the sensation of heartburn. -gastroesophageal reflux disease (gerd) is characterized people when they eat certain foods or during stressful events. -these triggers seem to aggravate symptoms but not cause them. -dietary treatment hinges on identifying and avoiding individual foods that aggravate symptoms; small meals may also be benefi- cial. -people with colitis, an inflammation of the large intestine, may also suffer from severe diarrhea. -they often benefit from complete bowel rest and medication. -if treatment fails, surgery to remove the colon and rectum may be necessary. -treatment for diarrhea depends on cause and severity, but it al- ways begins with rehydration.3 mild diarrhea may subside with simple rest and extra liquids (such as clear juices and soups) to re- place fluid losses. -however, call a physician if diarrhea is bloody or if it worsens or persists especially in an infant, young child, eld- erly person, or person with a compromised immune system. -se- vere diarrhea can be life threatening. -constipation like diarrhea, constipation describes a symptom, not a disease. -each person s gi tract has its own cycle of waste elimination, which depends on its owner s health, the type of food eaten, when it was eaten, and when the person takes time to defecate. -what s normal for some people may not be normal for others. -some people have bowel movements three times a day; others by symptoms of reflux occurring two or more times a week. -heartburn: a burning sensation in the chest area caused by backflow of stomach acid into the esophagus. -heimlich (hime-lick) maneuver (abdominal thrust maneuver): a technique for dislodging an object from the trachea of a choking person (see figure h3-2); named for the physician who developed it. -hemorrhoids (hem-oh-royds): painful swelling of the veins surrounding the rectum. -hiccups (hick-ups): repeated cough-like sounds and jerks that are produced when an involun- tary spasm of the diaphragm muscle sucks air down the windpipe; also spelled hiccoughs. -indigestion: incomplete or uncomfortable digestion, usually accompanied by pain, nausea, vomiting, heartburn, intestinal gas, or belching. -in (cid:2) not irritable bowel syndrome: an intestinal disorder of unknown cause. -symptoms include abdominal discomfort and cramping, diarrhea, constipation, or alternating diarrhea and constipation. -larynx: the upper part of the air passageway that contains the vocal cords; also called the voice box (see figure h3-1). -laxatives: substances that loosen the bowels and thereby prevent or treat constipation. -mineral oil: a purified liquid derived from petroleum and used to treat constipation. -peptic ulcer: a lesion in the mucous membrane of either the stomach (a gastric ulcer) or the duodenum (a duodenal ulcer). -peptic (cid:2) concerning digestion trachea (trake-ee-uh): the air passageway from the larynx to the lungs; also called the windpipe. -ulcer: a lesion of the skin or mucous membranes characterized by inflammation and damaged tissues. -see also peptic ulcer. -vomiting: expulsion of the contents of the stomach up through the esophagus to the mouth. -may have them three times a week. -the symptoms of constipa- tion include straining during bowel movements, hard stools, and infrequent bowel movements (fewer than three per week).4 ab- s i b r o c / y e l l e k s l e i r a personal hygiene (such as regular hand washing with soap and water) and safe food preparation (as described in chapter 19) are easy and effective steps to take in preventing diarrheal diseases. -dominal discomfort, headaches, backaches, and the passing of gas sometimes accompany constipation. -often a person s lifestyle may cause constipation. -being too busy to respond to the defecation signal is a common complaint. -if a person receives the signal to defecate and ignores it, the sig- nal may not return for several hours. -in the meantime, water con- tinues to be withdrawn from the fecal matter, so when the person does defecate, the stools are dry and hard. -in such a case, a per- son s daily regimen may need to be revised to allow time to have a bowel movement when the body sends its signal. -one possibil- ity is to go to bed earlier in order to rise earlier, allowing ample time for a leisurely breakfast and a movement. -although constipation usually reflects lifestyle habits, in some cases it may be a side effect of medication or may reflect a med- ical problem such as tumors that are obstructing the passage of waste. -if discomfort is associated with passing fecal matter, seek medical advice to rule out disease. -once this has been done, di- etary or other measures for correction can be considered. -one dietary measure that may be appropriate is to increase di- etary fiber to 20 to 25 grams per day over the course of a week or two. -fibers found in fruits, vegetables, and whole grains help to prevent constipation by increasing fecal mass. -in the gi tract, fiber attracts water, creating soft, bulky stools that stimulate bowel con- tractions to push the contents along. -these contractions strengthen the intestinal muscles. -the improved muscle tone, to- gether with the water content of the stools, eases elimination, re- ducing the pressure in the rectal veins and helping to prevent hemorrhoids. -chapter 4 provides more information on fiber s role in maintaining a healthy colon and reducing the risks of colon cancer and diverticulosis. -diverticulosis is a condition in which the intestinal walls develop bulges in weakened areas, most com- monly in the colon (see figure h3-3). -these bulging pockets, known as diverticula, can worsen constipation, entrap feces, and become painfully infected and inflamed (diverticulitis). -treat- ment may require hospitalization, antibiotics, or surgery. -figure h3-3 diverticula in the colon diverticula may develop anywhere along the gi tract, but they are most common in the colon. -diverticula (plural) diverticulum (singular) common digestive problems 95 drinking plenty of water in conjunction with eating high-fiber foods also helps to prevent constipation. -the increased bulk phys- ically stimulates the upper gi tract, promoting peristalsis through- out. -similarly, physical activity improves the muscle tone and motility of the digestive tract. -as little as 30 minutes of physical activity a day can help prevent or alleviate constipation. -eating prunes or dried plums as some have renamed them can also be helpful. -prunes are high in fiber and also con- tain a laxative substance. -* if a morning defecation is desired, a person can drink prune juice at bedtime; if the evening is pre- ferred, the person can drink prune juice with breakfast. -these suggested changes in lifestyle or diet should correct chronic constipation without the use of laxatives, enemas, or mineral oil, although television commercials often try to per- suade people otherwise. -one of the fallacies often perpetrated by advertisements is that one person s successful use of a product is a good recommendation for others to use that product. -as a matter of fact, diet changes that relieve constipation for one person may increase the constipation of another. -for in- stance, increasing fiber intake stimulates peristalsis and helps the person with a sluggish colon. -some people, though, have a spas- tic type of constipation, in which peristalsis promotes strong con- tractions that close off a segment of the colon and prevent passage; for these people, increasing fiber intake would be ex- actly the wrong thing to do. -a person who seems to need products such as laxatives fre- quently should seek a physician s advice. -one potentially harmful but currently popular practice is colonic irrigation the inter- nal washing of the large intestine with a powerful enema ma- chine. -such an extreme cleansing is not only unnecessary, but it can be hazardous, causing illness and death from equipment con- tamination, electrolyte depletion, and intestinal perforation. -less extreme practices can cause problems, too. -frequent use of laxa- tives and enemas can lead to dependency; upset the body s fluid, salt, and mineral balances; and, in the case of mineral oil, interfere with the absorption of fat-soluble vitamins. -(mineral oil dissolves the vitamins but is not itself absorbed. -instead, it leaves the body, carrying the vitamins with it.) -belching and gas many people complain of problems that they attribute to exces- sive gas. -for some, belching is the complaint. -others blame in- testinal gas for abdominal discomforts and embarrassment. -most people believe that the problems occur after they eat certain foods. -this may be the case with intestinal gas, but belching re- sults from swallowing air. -the best advice for belching seems to be to eat slowly, chew thoroughly, and relax while eating. -everyone swallows a little bit of air with each mouthful of food, but people who eat too fast may swallow too much air and then have to belch. -ill-fitting dentures, carbonated beverages, and chewing gum can also contribute to the swallowing of air with re- sultant belching. -occasionally, belching can be a sign of a more serious disorder, such as gallbladder disease or a peptic ulcer. -* this substance is dihydroxyphenyl isatin. -96 highlight 3 absorption diseases, however, require medical treatment.) -healthy people expel several hundred milliliters of gas several times a day. -almost all (99 percent) of the gases expelled nitro- gen, oxygen, hydrogen, methane, and carbon dioxide are odorless. -the remaining volatile gases are the infamous ones. -foods that produce gas usually must be determined individu- ally. -the most common offenders are foods rich in the carbohy- drates sugars, starches, and fibers. -when partially digested carbohydrates reach the large intestine, bacteria digest them, giv- ing off gas as a by-product. -people can test foods suspected of forming gas by omitting them individually for a trial period to see if there is any improvement. -heartburn and acid indigestion . -c n i s o i d u t s a r a l o p people troubled by gas need to determine which foods bother them and then eat those foods in moderation. -people who eat or drink too fast may also trigger hiccups, the repeated spasms that produce a cough-like sound and jerky movement. -normally, hiccups soon subside and are of no med- ical significance, but they can be bothersome. -the most effective cure is to hold the breath for as long as possible, which helps to relieve the spasms of the diaphragm. -although expelling gas can be a humiliating experience, it is quite normal. -(people who experience painful bloating from mal- almost everyone has experienced heartburn at one time or another, usually soon after eating a meal. -medically known as gastroesophageal reflux, heartburn is the painful sensation a person feels behind the breastbone when the lower esophageal sphincter allows the stomach contents to reflux into the esophagus (see figure h3-4). -this may happen if a person eats or drinks too much (or both). -tight clothing and even changes of position (lying down, bending over) can cause it, too, as can some medications and smoking. -weight gain and overweight increase the frequency, severity, and duration of heartburn symptoms.5 a defect of the sphincter muscle itself is a possible, but less common, cause. -figure h3-4 gastroesophageal reflux esophagus reflux diaphragm weakened lower esophageal sphincter acidic stomach contents stomach if the heartburn is not caused by an anatomical defect, treatment is fairly simple. -to avoid such misery in the fu- ture, the person needs to learn to eat less at a sitting, chew food more thor- oughly, and eat it more slowly. -addi- tional strategies are presented in table h3-1 at the end of this highlight. -as far as acid indigestion is con- cerned, recall from chapter 3 that the strong acidity of the stomach is a desir- able condition television commercials for antacids and acid controllers notwithstanding. -people who overeat or eat too quickly are likely to suffer from indigestion. -the muscular reac- tion of the stomach to unchewed lumps or to being overfilled may be so violent that it upsets normal peristalsis. -when this happens, overeaters may taste the stomach acid and feel pain. -responding to advertisements, they may reach for antacids or acid con- trollers. -both of these drugs were orig- inally designed to treat gi illnesses such as ulcers. -as is true of most over-the- counter medicines, antacids and acid controllers should be used only infrequently for occasional heart- burn; they may mask or cause problems if used regularly. -acid- blocking drugs weaken the defensive mucous barrier of the gi tract, thereby increasing the risks of infections such as pneumo- nia, especially in vulnerable populations like the elderly.6 instead of self-medicating, people who suffer from frequent and regular bouts of heartburn and indigestion should try the strategies presented in the table below. -if problems continue, they may need to see a physician, who can prescribe specific medication to control gastroesophageal reflux. -without treatment, the re- peated splashes of acid can severely damage the cells of the esophagus, creating a condition known as barrett s esophagus.7 at that stage, the risk of cancer in the throat or esophagus in- creases dramatically. -to repeat, if symptoms persist, see a doc- tor don t self-medicate. -ulcers ulcers are another common digestive problem. -an ulcer is a le- sion (a sore) and a peptic ulcer is a lesion in the lining of the stomach (gastric ulcers) or the duodenum of the small intestine (duodenal ulcers). -the compromised lining is left unprotected and exposed to gastric juices, which can be painful. -in some cases, ulcers can cause internal bleeding. -if gi bleeding is exces- sive, iron deficiency may develop. -ulcers that perforate the gi lin- ing can pose life-threatening complications. -many people naively believe that an ulcer is caused by stress or spicy foods, but this is not the case. -the stomach lining in a healthy person is well protected by its mucous coat. -what, then, causes ulcers to form? -three major causes of ulcers have been identified: bacterial in- fection with helicobacter pylori (commonly abbreviated h. pylori); common digestive problems 97 the use of certain anti-inflammatory drugs such as aspirin, ibupro- fen, and naproxen; and disorders that cause excessive gastric acid secretion. -most commonly, ulcers develop in response to h. pylori infection.8 the cause of the ulcer dictates the type of medication used in treatment. -for example, people with ulcers caused by in- fection receive antibiotics, whereas those with ulcers caused by medicines discontinue their use. -in addition, all treatment plans aim to relieve pain, heal the ulcer, and prevent recurrence. -the regimen for ulcer treatment is to treat for infection, elimi- nate any food that routinely causes indigestion or pain, and avoid coffee and caffeine- and alcohol-containing beverages. -both reg- ular and decaffeinated coffee stimulate acid secretion and so ag- gravate existing ulcers. -ulcers and their treatments highlight the importance of not self-medicating when symptoms persist. -people with h. pylori in- fection often take over-the-counter acid controllers to relieve the pain of their ulcers when, instead, they need physician-prescribed antibiotics. -suppressing gastric acidity not only fails to heal the ul- cer, but it also actually worsens inflammation during an h. pylori infection. -furthermore, h. pylori infection has been linked with stomach cancer, making prompt diagnosis and appropriate treat- ment essential.9 table h3-1 summarizes strategies to prevent or alleviate common gi problems. -many of these problems reflect hurried lifestyles. -for this reason, many of their remedies require that people slow down and take the time to eat leisurely; chew food thoroughly to prevent choking, heartburn, and acid indigestion; rest until vom- iting and diarrhea subside; and heed the urge to defecate. -in ad- dition, people must learn how to handle life s day-to-day problems and challenges without overreacting and becoming up- set; learn how to relax, get enough sleep, and enjoy life. -remem- ber, what s eating you may cause more gi distress than what you eat. -table h3-1 strategies to prevent or alleviate common gi problems gi problem strategies gi problem strategies choking diarrhea constipation take small bites of food. -chew thoroughly before swallowing. -don t talk or laugh with food in your mouth. -don t eat when breathing hard. -heartburn rest. -drink fluids to replace losses. -call for medical help if diarrhea persists. -eat a high-fiber diet. -drink plenty of fluids. -exercise regularly. -respond promptly to the urge to defecate. -ulcer belching eat slowly. -chew thoroughly. -relax while eating. -intestinal gas eat bothersome foods in moderation. -eat small meals. -drink liquids between meals. -sit up while eating; elevate your head when lying down. -wait 3 hours after eating before lying down. -wait 2 hours after eating before exercising. -refrain from wearing tight-fitting clothing. -avoid foods, beverages, and medications that aggravate your heartburn. -refrain from smoking cigarettes or using tobacco products. -lose weight if overweight. -take medicine as prescribed by your physician. -avoid coffee and caffeine- and alcohol- containing beverages. -avoid foods that aggravate your ulcer. -minimize aspirin, ibuprofen, and naproxen use. -refrain from smoking cigarettes. -98 highlight 3 nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 3, then to highlights nutrition on the net. -visit the digestive diseases section of the national insti- tute of diabetes, digestive, and kidney diseases: www.niddk.nih.gov/health/health.htm search for choking, vomiting, diarrhea, constipa- visit the patient information section of the american tion, heartburn, indigestion, and ulcers at the u.s. government health information site: www.healthfinder.gov college of gastroenterology: www.acg.gi.org learn more about h. pylori from the helicobacter founda- tion: www.helico.com visit the center for digestive health and nutrition: www.gihealth.com references 1. k. gotsch, j. l. annest, and p. holmgreen, nonfatal choking-related episodes among children-united states, 2001, morbidity and mortality weekly report 51 (2002): 945-948. -2. b. j. horwitz and r. s. fisher, the irritable bowel syndrome, new england journal of medicine 344 (2001): 1846-1850. -3. n. m. thielman and r. l. guerrant, acute infectious diarrhea, new england journal of medicine 350 (2004): 38-47. -4. a. lembo and m. camilleri, chronic consti- pation, new england journal of medicine 349 (2003): 1360-1368. -5. b. c. jacobson and coauthors, body-mass index and symptoms of gastroesophageal reflux in women, new england journal of medicine 354 (2006): 2340-2348. -6. r. j. f. laheij and coauthors, risk of commu- nity-acquired pneumonia and use of gastric acid-suppressive drugs, journal of the american medical association 292 (2004): 1955-1960. -7. n. shaheen and d. f. ransohoff, gastroe- sophageal reflux, barrett s esophagus, and esophageal cancer: scientific review, journal of the american medical association 287 (2002): 1972-1981. -8. s. suerbaum and p. michetti, helicobacter pylori infection, new england journal of medicine 347 (2002): 1175-1186. -9. n. uemura and coauthors, helicobacter pylori infection and the development of gastric cancer, new england journal of medi- cine 345 (2001): 784-789. this page intentionally left blank kevin summers/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow whether you are cramming for an exam or daydreaming about your next vacation, your brain needs carbohydrate to power its activities. -your muscles need carbohydrate to fuel their work, too, whether you are racing up the figure 4.10: animated! -carbohydrate digestion stairs to class or moving on the dance floor to your favorite music. -where can in the gi tract nutrition portfolio journal nutrition calculations: practice problems you get carbohydrate? -and are some foods healthier choices than others? -as you will learn from this chapter, whole grains, vegetables, legumes, and fruits naturally deliver ample carbohydrate and fiber with valuable vitamins and minerals and little or no fat. -milk products typically lack fiber, but they also provide carbohydrate along with an assortment of vitamins and minerals. -the carbohydrates: sugars, starches, and fibers a student, quietly studying a textbook, is seldom aware that within his brain cells, billions of glucose molecules are splitting to provide the energy that per- mits him to learn. -yet glucose provides nearly all of the energy the human brain uses daily. -similarly, a marathon runner, bursting across the finish line in an explosion of sweat and triumph, seldom gives credit to the glycogen fuel her muscles have devoured to help her finish the race. -yet, together, these two car- bohydrates glucose and its storage form glycogen provide about half of all the energy muscles and other body tissues use. -the other half of the body s en- ergy comes mostly from fat. -people don t eat glucose and glycogen directly. -when they eat foods rich in carbohydrates, their bodies receive glucose for immediate energy and into glycogen for reserve energy. -all plant foods whole grains, veg- etables, legumes, and fruits provide ample carbohydrate. -milk also con- tains carbohydrates. -many people mistakenly think of carbohydrates as fattening and avoid them when trying to lose weight. -such a strategy may be helpful if the car- bohydrates are the simple sugars of soft drinks, candy, and cookies, but it is counterproductive if the carbohydrates are the complex carbohydrates of whole grains, vegetables, and legumes. -as the next section explains, not all carbohydrates are created equal. -the chemist s view of carbohydrates the dietary carbohydrate family includes the simple carbohydrates (the sugars) and the complex carbohydrates (the starches and fibers). -the simple carbohy- drates are those that chemists describe as: monosaccharides single sugars disaccharides sugars composed of pairs of monosaccharides the complex carbohydrates are: polysaccharides large molecules composed of chains of monosaccharides c h a p t e r 4 chapter outline the chemist s view of carbohydrates the simple carbohydrates monosaccharides disaccharides the complex carbohydrates glycogen starches fibers digestion and absorption of carbohydrates carbohydrate digestion carbohydrate absorption lactose intolerance glucose in the body a preview of carbohydrate metabolism the con- stancy of blood glucose health effects and recommended intakes of sugars health effects of sugars controversies surrounding sugars recommended intakes of sugars health effects and recommended intakes of starch and fibers health effects of starch and fibers recommended intakes of starch and fibers from guidelines to groceries highlight 4 alternatives to sugar carbohydrates: compounds composed of carbon, oxygen, and hydrogen arranged as monosaccharides or multiples of monosaccharides. -most, but not all, carbohydrates have a ratio of one carbon molecule to one water molecule: (ch2o)n. carbo = carbon (c) hydrate = with water (h2o) simple carbohydrates (sugars): monosaccharides and disaccharides. -complex carbohydrates (starches and fibers): polysaccharides composed of straight or branched chains of monosaccharides. -101 102 chapter 4 figure 4-1 atoms and their bonds the four main types of atoms found in nutrients are hydrogen (h), oxygen (o), nitrogen (n), and carbon (c). -h 1 o 2 n 3 c 4 each atom has a characteristic number of bonds it can form with other atoms. -h h h c c o h h h notice that in this simple molecule of ethyl alcohol, each h has one bond, o has two, and each c has four. -to understand the structure of carbohydrates, look at the units of which they are made. -the monosaccharides most important in nutrition each contain 6 carbon atoms, 12 hydrogens, and 6 oxygens (written in shorthand as c6h12o6). -each atom can form a certain number of chemical bonds with other atoms: carbon atoms can form four bonds nitrogen atoms, three oxygen atoms, two hydrogen atoms, only one chemists represent the bonds as lines between the chemical symbols (such as c, n, o, and h) that stand for the atoms (see figure 4-1). -atoms form molecules in ways that satisfy the bonding requirements of each atom. -figure 4-1 includes the structure of ethyl alcohol, the active ingredient of alco- holic beverages, as an example. -the two carbons each have four bonds represented by lines; the oxygen has two; and each hydrogen has one bond connecting it to other atoms. -chemical structures bond according to these rules as dictated by nature. -most of the monosaccharides important in nu- trition are hexoses, simple sugars with six atoms of carbon and the formula c6h12o6. -hex = six in summary the carbohydrates are made of carbon (c), oxygen (o), and hydrogen (h). -each of these atoms can form a specified number of chemical bonds: carbon forms four, oxygen forms two, and hydrogen forms one. -the simple carbohydrates the following list of the most important simple carbohydrates in nutrition symbolizes them as hexagons and pentagons of different colors. -* three are monosaccharides: figure 4-2 chemical structure of glucose on paper, the structure of glucose has to be drawn flat, but in nature the five carbons and oxygen are roughly in a plane. -the atoms attached to the ring carbons extend above and below the plane. -o h h h c c h o h c h h c o h o h c o h h c o h monosaccharides (mon-oh-sack-uh-rides): carbohydrates of the general formula cnh2non that typically form a single ring. -see appendix c for the chemical structures of the monosaccharides. -mono = one saccharide = sugar glucose (gloo-kose): a monosaccharide; sometimes known as blood sugar or dextrose. -ose = carbohydrate = glucose glucose fructose galactose three are disaccharides: maltose (glucose + glucose) sucrose (glucose + fructose) lactose (glucose + galactose) monosaccharides the three monosaccharides important in nutrition all have the same numbers and kinds of atoms, but in different arrangements. -these chemical differences ac- count for the differing sweetness of the monosaccharides. -a pinch of purified glucose on the tongue gives only a mild sweet flavor, and galactose hardly tastes sweet at all. -fructose, however, is as intensely sweet as honey and, in fact, is the sugar primarily responsible for honey s sweetness. -glucose chemically, glucose is a larger and more complicated molecule than the ethyl alcohol shown in figure 4-1, but it obeys the same rules of chemistry: each car- bon atom has four bonds; each oxygen, two bonds; and each hydrogen, one bond. -figure 4-2 illustrates the chemical structure of a glucose molecule. -the diagram of a glucose molecule shows all the relationships between the atoms and proves simple on examination, but chemists have adopted even sim- pler ways to depict chemical structures. -figure 4-3 presents the chemical structure * fructose is shown as a pentagon, but like the other monosaccharides, it has six carbons (as you will see in figure 4-4). -the carbohydrates: sugars, starches, and fibers 103 figure 4-3 simplified diagrams of glucose ch2oh o h h oh h ho h oh h oh ch2oh o oh ho oh oh c c c c o c c the lines representing some of the bonds and the carbons at the corners are not shown. -now the single hydrogens are not shown, but lines still extend upward or downward from the ring to show where they belong. -another way to look at glucose is to notice that its six carbon atoms are all connected. -in this and other illustrations throughout this book, glucose is represented as a blue hexagon. -of glucose in a more simplified way by combining or omitting several symbols yet it conveys the same information. -commonly known as blood sugar, glucose serves as an essential energy source for all the body s activities. -its significance to nutrition is tremendous. -later sections explain that glucose is one of the two sugars in every disaccharide and the unit from which the polysaccharides are made almost exclusively. -one of these polysac- charides, starch, is the chief food source of energy for all the world s people; an- other, glycogen, is an important storage form of energy in the body. -glucose reappears frequently throughout this chapter and all those that follow. -fructose fructose is the sweetest of the sugars. -curiously, fructose has exactly the same chemical formula as glucose c6h12o6 but its structure differs (see figure 4-4). -the arrangement of the atoms in fructose stimulates the taste buds on the tongue to produce the sweet sensation. -fructose occurs naturally in fruits and honey; other sources include products such as soft drinks, ready-to-eat cereals, and desserts that have been sweetened with high-fructose corn syrup (defined on p. 118). -galactose the monosaccharide galactose occurs naturally as a single sugar in only a few foods. -galactose has the same numbers and kinds of atoms as glucose and fructose in yet another arrangement. -figure 4-5 shows galactose beside a mole- cule of glucose for comparison. -disaccharides the disaccharides are pairs of the three monosaccharides just described. -glucose occurs in all three; the second member of the pair is either fructose, galactose, or fructose (fruk-tose or frook-tose): a monosaccharide; sometimes known as fruit sugar or levulose. -fructose is found abundantly in fruits, honey, and saps. -fruct = fruit = fructose galactose (ga-lak-tose): a monosaccharide; part of the disaccharide lactose. -= galactose disaccharides (dye-sack-uh-rides): pairs of monosaccharides linked together. -see appendix c for the chemical structures of the disaccharides. -di = two figure 4-4 glucose and fructose two monosaccharides: figure 4-5 two monosaccharides: glucose and galactose can you see the similarities? -if you learned the rules in fig- ure 4-3, you will be able to see 6 carbons (numbered), 12 hydrogens (those shown plus one at the end of each single line), and 6 oxygens in both these compounds. -notice the similarities and the difference (highlighted in red) between glucose and galactose. -both have 6 carbons, 12 hydrogens, and 6 oxygens, but the position of one oh group differs slightly. -6 ch2oh 5 oh 3 4 ho o 2 oh 1 oh o 6 hoch2 5 ho 3 4 oh ch2oh 1 2 oh glucose fructose ch2oh o ch2oh o ho ho oh oh oh oh oh glucose oh galactose 104 chapter 4 figure 4-6 condensation of two monosaccharides to form a disaccharide ch2oh o ch2oh o ch2oh o ch2oh o oh ho oh h o oh oh oh ho oh oh h2o water glucose + glucose oh oh oh oh o + h2o water maltose an oh group from one glucose and an h atom from another glucose combine to create a molecule of h2o. -the two glucose molecules bond together with a single o atom to form the disaccharide maltose. -s e g a m i y t t e g / s e g a m i o d n e r t l a fruits package their simple sugars with fibers, vitamins, and minerals, making them a sweet and healthy snack. -another glucose. -these carbohydrates and all the other energy nutrients are put together and taken apart by similar chemical reactions: condensation and hydrolysis. -condensation to make a disaccharide, a chemical reaction known as conden- sation links two monosaccharides together (see figure 4-6). -a hydroxyl (oh) group from one monosaccharide and a hydrogen atom (h) from the other combine to cre- ate a molecule of water (h2o). -the two originally separate monosaccharides link to- gether with a single oxygen (o). -hydrolysis to break a disaccharide in two, a chemical reaction known as hydroly- sis occurs (see figure 4-7). -a molecule of water splits to provide the h and oh needed to complete the resulting monosaccharides. -hydrolysis reactions commonly occur during digestion. -maltose the disaccharide maltose consists of two glucose units. -maltose is pro- duced whenever starch breaks down as happens in human beings during carbohy- drate digestion. -it also occurs during the fermentation process that yields alcohol. -maltose is only a minor constituent of a few foods, most notably barley. -sucrose fructose and glucose together form sucrose. -because the fructose is acces- sible to the taste receptors, sucrose tastes sweet, accounting for some of the natural sweetness of fruits, vegetables, and grains. -to make table sugar, sucrose is refined from the juices of sugarcane and sugar beets, then granulated. -depending on the extent to which it is refined, the product becomes the familiar brown, white, and powdered sug- ars available at grocery stores. -figure 4-7 hydrolysis of a disaccharide bond broken ch2oh o ch2oh o ch2oh o ch2oh o oh ho oh o water h oh oh oh oh oh ho + oh ho oh oh oh oh bond broken maltose glucose + glucose the disaccharide maltose splits into two glucose molecules with h added to one and oh to the other (from the water molecule). -reminder: a hydrolysis reaction splits a molecule into two, with h added to one and oh to the other (from water); chapter 3 explained that hydrolysis reactions break down molecules during digestion. -condensation: a chemical reaction in which two reactants combine to yield a larger product. -maltose (mawl-tose): a disaccharide composed of two glucose units; sometimes known as malt sugar. -= maltose sucrose (sue-krose): a disaccharide composed of glucose and fructose; commonly known as table sugar, beet sugar, or cane sugar. -sucrose also occurs in many fruits and some vegetables and grains. -sucro = sugar = sucrose the carbohydrates: sugars, starches, and fibers 105 lactose the combination of galactose and glucose makes the disaccharide lactose, the principal carbohydrate of milk. -known as milk sugar, lactose contributes half of the energy (kcalories) provided by fat-free milk. -in summary six simple carbohydrates, or sugars, are important in nutrition. -the three monosaccharides (glucose, fructose, and galactose) all have the same chemi- cal formula (c6h12o6), but their structures differ. -the three disaccharides (maltose, sucrose, and lactose) are pairs of monosaccharides, each containing a glucose paired with one of the three monosaccharides. -the sugars derive pri- marily from plants, except for lactose and its component galactose, which come from milk and milk products. -two monosaccharides can be linked to- gether by a condensation reaction to form a disaccharide and water. -a disac- charide, in turn, can be broken into its two monosaccharides by a hydrolysis reaction using water. -the complex carbohydrates the simple carbohydrates are the sugars just mentioned the monosaccharides glu- cose, fructose, and galactose and the disaccharides maltose, sucrose, and lactose. -in contrast, the complex carbohydrates contain many glucose units and, in some cases, a few other monosaccharides strung together as polysaccharides. -three types of polysaccharides are important in nutrition: glycogen, starches, and fibers. -glycogen is a storage form of energy in the animal body; starches play that role in plants; and fibers provide structure in stems, trunks, roots, leaves, and skins of plants. -both glycogen and starch are built of glucose units; fibers are composed of a variety of monosaccharides and other carbohydrate derivatives. -glycogen glycogen is found to only a limited extent in meats and not at all in plants. -* for this reason, food is not a significant source of this carbohydrate. -however, glycogen does perform an important role in the body. -the human body stores glucose as glycogen many glucose molecules linked together in highly branched chains (see the left side of figure 4-8 on p. 106). -this arrangement permits rapid hydrolysis. -when the hormonal message release energy arrives at the glycogen storage sites in a liver or muscle cell, enzymes respond by attacking the many branches of glyco- gen simultaneously, making a surge of glucose available. -** starches the human body stores glucose as glycogen, but plant cells store glucose as starches long, branched or unbranched chains of hundreds or thousands of glu- cose molecules linked together (see the middle and right side of figure 4-8). -these gi- ant starch molecules are packed side by side in grains such as wheat or rice, in root crops and tubers such as yams and potatoes, and in legumes such as peas and beans. -when you eat the plant, your body hydrolyzes the starch to glucose and uses the glucose for its own energy purposes. -all starchy foods come from plants. -grains are the richest food source of starch, providing much of the food energy for people all over the world rice in asia; * glycogen in animal muscles rapidly hydrolyzes after slaughter. -** normally, only liver cells can produce glucose from glycogen to be sent directly to the blood; muscle cells can also produce glucose from glycogen, but must use it themselves. -muscle cells can restore the blood glucose level indirectly, however, as chapter 7 explains. -. -c n i s o i d u t s a r a l o p major sources of starch include grains (such as rice, wheat, millet, rye, barley, and oats), legumes (such as kidney beans, black-eyed peas, pinto beans, navy beans, and garbanzo beans), tubers (such as potatoes), and root crops (such as yams and cassava). -lactose (lak-tose): a disaccharide composed of glucose and galactose; commonly known as milk sugar. -lact = milk = lactose polysaccharides: compounds composed of many monosaccharides linked together. -an intermediate string of three to ten monosaccharides is an oligosaccharide. -poly = many oligo = few glycogen (gly-ko-jen): an animal polysaccharide composed of glucose; manufactured and stored in the liver and muscles as a storage form of glucose. -glycogen is not a significant food source of carbohydrate and is not counted as one of the complex carbohydrates in foods. -glyco = glucose gen = gives rise to starches: plant polysaccharides composed of glucose. -106 chapter 4 figure 4-8 glycogen and starch molecules compared (small segments) notice the more highly branched the structure, the greater the number of ends from which glucose can be released. -(these units would have to be magnified millions of times to appear at the size shown in this figure. -for details of the chemical structures, see appendix c.) glycogen starch (amylopectin) starch (amylose) a glycogen molecule contains hundreds of glucose units in highly branched chains. -each new glycogen molecule needs a special protein for the attachment of the first glucose (shown here in red). -a starch molecule contains hundreds of glucose molecules in either occasionally branched chains (amylopectin) or unbranched chains (amylose). -wheat in canada, the united states, and europe; corn in much of central and south america; and millet, rye, barley, and oats elsewhere. -legumes and tubers are also important sources of starch. -fibers dietary fibers are the structural parts of plants and thus are found in all plant- derived foods vegetables, fruits, whole grains, and legumes. -most dietary fibers are polysaccharides. -as mentioned earlier, starches are also polysacharides, but dietary fibers differ from starches in that the bonds between their monosaccharides cannot be broken down by digestive enzymes in the body. -for this reason, dietary fibers are often described as nonstarch polysaccharides. -* figure 4-9 illustrates the difference in the bonds that link glucose molecules together in starch with those found in the fiber cellulose. -because dietary fibers pass through the body, they contribute no monosac- charides, and therefore little or no energy. -even though most foods contain a variety of fibers, researchers often sort dietary fibers into two groups according to their solubility. -such distinctions help to explain their actions in the body. -soluble fibers some dietary fibers dissolve in water (soluble fibers), form gels (viscous), and are easily digested by bacteria in the colon (fermentable). -com- monly found in oats, barley, legumes, and citrus fruits, soluble fibers are most often associated with protecting against heart disease and diabetes by lowering blood cholesterol and glucose levels, respectively.1 insoluble fibers other fibers do not dissolve in water (insoluble fibers), do not form gels (nonviscous), and are less readily fermented. -found mostly in whole grains (bran) and vegetables, insoluble fibers promote bowel movements and alleviate constipation. -fiber sources as mentioned, dietary fibers occur naturally in plants. -when these fibers have been extracted from plants or manufactured and then added to foods or used in supplements they are called functional fibers if they have beneficial health *the nonstarch polysaccharide fibers include cellulose, hemicelluloses, pectins, gums, and mucilages. -fibers also include some nonpolysaccharides such as lignins, cutins, and tannins. -**dietary fibers are fermented by bacteria in the colon to short-chain fatty acids, which are absorbed and metabolized by cells in the gi tract and liver (chapter 5 describes fatty acids). -dietary fibers: in plant foods, the nonstarch polysaccharides that are not digested by human digestive enzymes, although some are digested by gi tract bacteria. -dietary fibers include cellulose, hemicelluloses, pectins, gums, and mucilages and the nonpolysaccharides lignins, cutins, and tannins. -soluble fibers: indigestible food components that dissolve in water to form a gel. -an example is pectin from fruit, which is used to thicken jellies. -viscous: a gel-like consistency. -fermentable: the extent to which bacteria in the gi tract can break down fibers to fragments that the body can use. -** insoluble fibers: indigestible food components that do not dissolve in water. -examples include the tough, fibrous structures found in the strings of celery and the skins of corn kernels. -the carbohydrates: sugars, starches, and fibers 107 figure 4-9 ecules compared (small segments) starch and cellulose mol- the bonds that link the glucose mole- cules together in cellulose are different from the bonds in starch (and glyco- gen). -human enzymes cannot digest cellulose. -see appendix c for chemical structures and descriptions of linkages. -starch cellulose dietary fibers occur naturally in intact plants. -functional fibers have been extracted from plants or manufactured and have beneficial effects in human beings. -total fiber is the sum of dietary fibers and functional fibers. -effects. -cellulose in cereals, for example, is a dietary fiber, but when consumed as a supplement to alleviate constipation, cellulose is considered a functional fiber. -total fiber refers to the sum of dietary fibers and functional fibers. -these terms were cre- ated by the dri committee to accommodate products that may contain new fiber sources, but consumers may find them too confusing to be used on food labels.2 resistant starches a few starches are classified as dietary fibers. -known as re- sistant starches, these starches escape digestion and absorption in the small intes- tine. -starch may resist digestion for several reasons, including the individual s efficiency in digesting starches and the food s physical properties. -resistant starch is common in whole legumes, raw potatoes, and unripe bananas. -phytic acid althought not classified as a dietary fiber, phytic acid is often found accompanying them in the same foods. -because of this close association, re- searchers have been unable to determine whether it is the dietary fiber, the phytic acid, or both, that binds with minerals, preventing their absorption. -this binding presents a risk of mineral deficiencies, but the risk is minimal when total fiber intake is reasonable and mineral intake adequate. -the nutrition consequences of such mineral losses are described further in chapters 12 and 13. in summary the complex carbohydrates are the polysaccharides (chains of monosaccha- rides): glycogen, starches, and dietary fibers. -both glycogen and starch are storage forms of glucose glycogen in the body, and starch in plants and both yield energy for human use. -the dietary fibers also contain glucose (and other monosaccharides), but their bonds cannot be broken by human diges- tive enzymes, so they yield little, if any, energy. -the accompanying table sum- marizes the carbohydrate family of compounds. -the carbohydrate family simple carbohydrates (sugars) complex carbohydrates monosaccharides: polysaccharides: glucose fructose galactose disaccharides: maltose sucrose lactose glycogena starches fibers aglycogen is a complex carbohydrate (a polysaccharide) but not a dietary source of carbohydrate. -digestion and absorption of carbohydrates the ultimate goal of digestion and absorption of sugars and starches is to break them into small molecules chiefly glucose that the body can absorb and use. -the large starch molecules require extensive breakdown; the disaccharides need only be broken once and the monosaccharides not at all. -the initial splitting begins in the mouth; the final splitting and absorption occur in the small intestine; and conversion to a common energy currency (glucose) takes place in the liver. -the details follow. -resistant starches: starches that escape digestion and absorption in the small intestine of healthy people. -phytic (fye-tick) acid: a nonnutrient component of plant seeds; also called phytate (fye-tate). -phytic acid occurs in the husks of grains, legumes, and seeds and is capable of binding minerals such as zinc, iron, calcium, magnesium, and copper in insoluble complexes in the intestine, which the body excretes unused. -108 chapter 4 the short chains of glucose units that result from the breakdown of starch are known as dextrins. -the word sometimes appears on food labels because dextrins can be used as thickening agents in processed foods. -reminder: a bolus is a portion of food swallowed at one time. -carbohydrate digestion figure 4-10 traces the digestion of carbohydrates through the gi tract. -when a per- son eats foods containing starch, enzymes hydrolyze the long chains to shorter chains, the short chains to disaccharides, and, finally, the disaccharides to mono- saccharides. -this process begins in the mouth. -in the mouth in the mouth, thoroughly chewing high-fiber foods slows eating and stimulates the flow of saliva. -the salivary enzyme amylase starts to work, hydrolyz- ing starch to shorter polysaccharides and to the disaccharide maltose. -in fact, you can taste the change if you hold a piece of starchy food like a cracker in your mouth for a few minutes without swallowing it the cracker begins tasting sweeter as the enzyme acts on it. -because food is in the mouth for only a short time, very little car- bohydrate digestion takes place there; it begins again in the small intestine. -in the stomach the swallowed bolus mixes with the stomach s acid and pro- tein-digesting enzymes, which inactivate salivary amylase. -thus the role of salivary amylase in starch digestion is relatively minor. -to a small extent, the stomach s acid continues breaking down starch, but its juices contain no enzymes to digest carbo- hydrate. -fibers linger in the stomach and delay gastric emptying, thereby providing a feeling of fullness and satiety. -in the small intestine the small intestine performs most of the work of carbohy- drate digestion. -a major carbohydrate-digesting enzyme, pancreatic amylase, en- ters the intestine via the pancreatic duct and continues breaking down the polysaccharides to shorter glucose chains and maltose. -the final step takes place on the outer membranes of the intestinal cells. -there specific enzymes break down specific disaccharides: maltase breaks maltose into two glucose molecules. -sucrase breaks sucrose into one glucose and one fructose molecule. -lactase breaks lactose into one glucose and one galactose molecule. -k c o t s r e p u s / k c o t s a n a n a b when a person eats carbohydrate-rich foods, the body receives a valuable commodity glucose. -reminder: in general, the word ending ase iden- tifies an enzyme, and the beginning of the word identifies the molecule that the enzyme works on. -starches and sugars are called available carbohydrates because human digestive enzymes break them down for the body s use. -in contrast, fibers are called unavailable carbohydrates because human digestive enzymes cannot break their bonds. -at this point, all polysaccharides and disaccharides have been broken down to monosaccharides mostly glucose molecules, with some fructose and galactose molecules as well. -in the large intestine within one to four hours after a meal, all the sugars and most of the starches have been digested. -only the fibers remain in the digestive tract. -fibers in the large intestine attract water, which softens the stools for passage without straining. -also, bacteria in the gi tract ferment some fibers. -this process generates water, gas, and short-chain fatty acids (described in chapter 5). -* the colon uses these small fat molecules for energy. -metabolism of short-chain fatty acids also occurs in the cells of the liver. -fibers, therefore, can contribute some en- ergy (1.5 to 2.5 kcalories per gram), depending on the extent to which they are bro- ken down by bacteria and the fatty acids are absorbed. -amylase (am-ih-lace): an enzyme that hydrolyzes amylose (a form of starch). -amylase is a carbohydrase, an enzyme that breaks down carbohydrates. -satiety (sah-tie-eh-tee): the feeling of fullness and satisfaction that occurs after a meal and inhibits eating until the next meal. -satiety determines how much time passes between meals. -sate = to fill maltase: an enzyme that hydrolyzes maltose sucrase: an enzyme that hydrolyzes sucrose lactase: an enzyme that hydrolyzes lactose carbohydrate absorption glucose is unique in that it can be absorbed to some extent through the lining of the mouth, but for the most part, nutrient absorption takes place in the small intestine. -glucose and galactose traverse the cells lining the small intestine by active trans- port; fructose is absorbed by facilitated diffusion, which slows its entry and produces a smaller rise in blood glucose. -likewise, unbranched chains of starch are digested slowly and produce a smaller rise in blood glucose than branched chains, which have many more places for enzymes to attack and release glucose rapidly. -as the blood from the intestines circulates through the liver, cells there take up fructose and galactose and convert them to other compounds, most often to glu- * the short-chain fatty acids produced by gi bacteria are primarily acetic acid, propionic acid, and butyric acid. -the carbohydrates: sugars, starches, and fibers 109 figure 4-10 animated! -carbohydrate digestion in the gi tract to test your understanding of these concepts, log on to www.thomsonedu.com/login starch fiber mouth and salivary glands the salivary glands secrete saliva into the mouth to moisten the food. -the salivary enzyme amylase begins digestion: amylase starch small polysaccharides, maltose salivary glands mouth mouth the mechanical action of the mouth crushes and tears fiber in food and mixes it with saliva to moisten it for swallowing. -stomach stomach acid inactivates salivary enzymes, halting starch digestion. -small intestine and pancreas the pancreas produces an amylase that is released through the pancreatic duct into the small intestine: pancreatic amylase starch small polysac- charides, maltose then disaccharidase enzymes on the surface of the small intestinal cells hydrolyze the disaccharides into monosaccharides: maltose maltase sucrose sucrase lactose lactase glucose + glucose fructose + glucose galactose + glucose intestinal cells absorb these monosaccharides. -stomach (liver) (gallbladder) stomach fiber is not digested, and it delays gastric emptying. -pancreas small intestine fiber is not digested, and it delays absorption of other nutrients. -large intestine most fiber passes intact through the digestive tract to the large intestine. -here, bacterial enzymes digest fiber: small intestine large intestine bacterial enzymes short-chain fatty acids, gas some fiber fiber holds water; regulates bowel activity; and binds substances such as bile, cholesterol, and some minerals, carrying them out of the body. -cose, as shown in figure 4-11 (p. 110). -thus all disaccharides provide at least one glucose molecule directly, and they can provide another one indirectly through the conversion of fructose and galactose to glucose. -110 chapter 4 figure 4-11 absorption of monosaccharides 1 monosaccharides, the end products of carbohydrate digestion, enter the capillaries of the intestinal villi. -small intestine 2 monosaccharides travel to the liver via the portal vein. -3 in the liver, galactose and fructose are converted to glucose. -key: glucose fructose galactose in summary in the digestion and absorption of carbohydrates, the body breaks down starches into the disaccharide maltose. -maltose and the other disaccharides (lac- tose and sucrose) from foods are broken down into monosaccharides. -then monosaccharides are converted mostly to glucose to provide energy for the cells work. -the fibers help to regulate the passage of food through the gi system and slow the absorption of glucose, but they contribute little, if any, energy. -lactose intolerance normally, the intestinal cells produce enough of the enzyme lactase to ensure that the disaccharide lactose found in milk is both digested and absorbed efficiently. -lac- tase activity is highest immediately after birth, as befits an infant whose first and only food for a while will be breast milk or infant formula. -in the great majority of the world s populations, lactase activity declines dramatically during childhood and adolescence to about 5 to 10 percent of the activity at birth. -only a relatively small percentage (about 30 percent) of the people in the world retain enough lactase to di- gest and absorb lactose efficiently throughout adult life. -symptoms when more lactose is consumed than the available lactase can han- dle, lactose molecules remain in the intestine undigested, attracting water and causing bloating, abdominal discomfort, and diarrhea the symptoms of lactose intolerance. -the undigested lactose becomes food for intestinal bacteria, which multiply and produce irritating acid and gas, further contributing to the discom- fort and diarrhea. -causes as mentioned, lactase activity commonly declines with age. -lactase de- ficiency may also develop when the intestinal villi are damaged by disease, certain medicines, prolonged diarrhea, or malnutrition. -depending on the extent of the in- testinal damage, lactose malabsorption may be temporary or permanent. -in ex- tremely rare cases, an infant is born with a lactase deficiency. -lactose intolerance: a condition that results from inability to digest the milk sugar lactose; characterized by bloating, gas, abdominal discomfort, and diarrhea. -lactose intolerance differs from milk allergy, which is caused by an immune reaction to the protein in milk. -lactase deficiency: a lack of the enzyme required to digest the disaccharide lactose into its component monosaccharides (glucose and galactose). -the carbohydrates: sugars, starches, and fibers 111 prevalence the prevalence of lactose intolerance varies widely among ethnic groups, indicating that the trait is genetically determined. -the prevalence of lactose intolerance is lowest among scandinavians and other northern europeans and highest among native north americans and southeast asians. -dietary changes managing lactose intolerance requires some dietary changes, although total elimination of milk products usually is not necessary. -excluding all milk products from the diet can lead to nutrient deficiencies because these foods are a major source of several nutrients, notably the mineral calcium, vitamin d, and the b vitamin riboflavin. -fortunately, many people with lactose intolerance can consume foods containing up to 6 grams of lactose (1/2 cup milk) without symptoms. -the most successful strategies are to increase intake of milk products gradually, take them with other foods in meals, and spread their intake throughout the day. -a change in the gi bacteria, not the reappearance of the missing enzyme, accounts for the ability to adapt to milk products. -importantly, most lactose-intolerant individu- als need to manage their dairy consumption rather than restrict it.3 in many cases, lactose-intolerant people can tolerate fermented milk products such as yogurt and kefir.4 the bacteria in these products digest lactose for their own use, thus reducing the lactose content. -even when the lactose content is equivalent to milk s, yogurt produces fewer symptoms. -hard cheeses, such as cheddar, and cot- tage cheese are often well tolerated because most of the lactose is removed with the whey during manufacturing. -lactose continues to diminish as cheese ages. -many lactose-intolerant people use commercially prepared milk products that have been treated with an enzyme that breaks down the lactose. -alternatively, they take enzyme tablets with meals or add enzyme drops to their milk. -the enzyme hydrolyzes much of the lactose in milk to glucose and galactose, which lactose- intolerant people can absorb without ill effects. -because people s tolerance to lactose varies widely, lactose-restricted diets must be highly individualized. -a completely lactose-free diet can be difficult because lac- tose appears not only in milk and milk products but also as an ingredient in many nondairy foods such as breads, cereals, breakfast drinks, salad dressings, and cake mixes. -people on strict lactose-free diets need to read labels and avoid foods that include milk, milk solids, whey (milk liquid), and casein (milk protein, which may contain traces of lactose). -they also need to check all medications with the pharmacist because 20 percent of prescription drugs and 5 percent of over-the- counter drugs contain lactose as a filler. -people who consume few or no milk products must take care to meet riboflavin, vitamin d, and calcium needs. -later chapters on the vitamins and minerals offer help with finding good nonmilk sources of these nutrients. -in summary lactose intolerance is a common condition that occurs when there is insuffi- cient lactase to digest the disaccharide lactose found in milk and milk prod- ucts. -symptoms include gi distress. -because treatment requires limiting milk intake, other sources of riboflavin, vitamin d, and calcium must be included in the diet. -estimated prevalence of lactose intolerance: (cid:2)80% southeast asians 80% native americans 75% african americans 70% mediterranean peoples 60% inuits 50% hispanics 20% caucasians (cid:3)10% northern europeans lactose in selected foods: whole-wheat bread, 1 slice dinner roll, 1 cheese, 1 oz cheddar or american parmesan or cream doughnut (cake type), 1 chocolate candy, 1 oz sherbet, 1 c cottage cheese (low-fat), 1 c ice cream, 1 c milk, 1 c yogurt (low-fat), 1 c 0.5 g 0.5 g 0.5 g 0.8 g 1.2 g 2.3 g 4.0 g 7.5 g 9.0 g 12.0 g 15.0 g note: yogurt is often enriched with nonfat milk solids, which increase its lactose content to a level higher than milk s. glucose in the body the primary role of the available carbohydrates in human nutrition is to supply the body s cells with glucose for energy. -starch contributes most to the body s glu- cose supply, but as explained earlier, any of the monosaccharides can also provide glucose. -kefir (keh-fur): a fermented milk created by adding lactobacillus acidophilus and other bacteria that break down lactose to glucose and galactose, producing a sweet, lactose- free product. -112 chapter 4 the study of sugars is known as glycobiology. -these combination molecules are known as gly- coproteins and glycolipids, respectively. -the carbohydrates of grains, vegetables, fruits, and legumes supply most of the energy in a healthful diet. -gluconeogenesis (gloo-ko-nee-oh-jen-ih- sis): the making of glucose from a noncarbohydrate source (described in more detail in chapter 7). -gluco = glucose neo = new genesis = making protein-sparing action: the action of carbohydrate (and fat) in providing energy that allows protein to be used for other purposes. -scientists have long known that providing energy is glucose s primary role in the body, but they have only recently uncovered additional roles that glucose and other sugars perform in the body.5 sugar molecules dangle from many of the body s protein and fat molecules, with dramatic consequences. -sugars attached to a protein change the protein s shape and function; when they bind to lipids in a cell s membranes, sugars alter the way cells recognize each other.6 cancer cells coated with sugar molecules, for example, are able to sneak by the cells of the im- mune system. -armed with this knowledge, scientists are now trying to use sugar molecules to create an anticancer vaccine. -further advances in knowledge are sure to reveal numerous ways these simple, yet remarkable, sugar molecules influence the health of the body. -a preview of carbohydrate metabolism glucose plays the central role in carbohydrate metabolism. -this brief discussion provides just enough information about carbohydrate metabolism to illustrate that the body needs and uses glucose as a chief energy nutrient. -chapter 7 pro- vides a full description of energy metabolism. -s e g a m i r e t i p u j / x i p d o o f / t r a t a e l n a i r b storing glucose as glycogen the liver stores about one-third of the body s total glycogen and releases glucose into the bloodstream as needed. -after a meal, blood glucose rises, and liver cells link the excess glucose molecules by condensation reac- tions into long, branching chains of glycogen. -when blood glucose falls, the liver cells break glycogen by hydrolysis reactions into single molecules of glucose and release them into the bloodstream. -thus glucose becomes available to supply energy to the brain and other tissues regardless of whether the person has eaten recently. -muscle cells can also store glucose as glycogen (the other two-thirds), but they hoard most of their supply, using it just for themselves during exercise. -the brain maintains a small amount of glycogen, which is thought to provide an emergency energy reserve during times of severe glucose deprivation.7 glycogen holds water and, therefore, is rather bulky. -the body can store only enough glycogen to provide energy for relatively short periods of time less than a day during rest and a few hours at most during exercise. -for its long-term energy reserves, for use over days or weeks of food deprivation, the body uses its abundant, water-free fuel, fat, as chapter 5 describes. -using glucose for energy glucose fuels the work of most of the body s cells. -in- side a cell, enzymes break glucose in half. -these halves can be put back together to make glucose, or they can be further broken down into even smaller fragments (never again to be reassembled to form glucose). -the small fragments can yield en- ergy when broken down completely to carbon dioxide and water (see chapter 7). -as mentioned, the liver s glycogen stores last only for hours, not for days. -to keep providing glucose to meet the body s energy needs, a person has to eat dietary car- bohydrate frequently. -yet people who do not always attend faithfully to their bodies carbohydrate needs still survive. -how do they manage without glucose from dietary carbohydrate? -do they simply draw energy from the other two energy-yielding nu- trients, fat and protein? -they do draw energy from them, but not simply. -making glucose from protein glucose is the preferred energy source for brain cells, other nerve cells, and developing red blood cells. -body protein can be con- verted to glucose to some extent, but protein has jobs of its own that no other nu- trient can do. -body fat cannot be converted to glucose to any significant extent. -thus, when a person does not replenish depleted glycogen stores by eating carbo- hydrate, body proteins are broken down to make glucose to fuel these special cells. -the conversion of protein to glucose is called gluconeogenesis literally, the making of new glucose. -only adequate dietary carbohydrate can prevent this use of protein for energy, and this role of carbohydrate is known as its protein- sparing action. -the carbohydrates: sugars, starches, and fibers 113 making ketone bodies from fat fragments an inadequate supply of carbo- hydrate can shift the body s energy metabolism in a precarious direction. -with less carbohydrate providing glucose to meet the brain s energy needs, fat takes an alter- native metabolic pathway; instead of entering the main energy pathway, fat frag- ments combine with each other, forming ketone bodies. -ketone bodies provide an alternate fuel source during starvation, but when their production exceeds their use, they accumulate in the blood, causing ketosis, a condition that disturbs the body s normal acid-base balance, as chapter 7 describes. -(highlight 9 explores ketosis and the health consequences of low-carbohydrate diets further.) -to spare body protein and prevent ketosis, the body needs at least 50 to 100 grams of carbohydrate a day. -dietary recommendations urge people to select abundantly from carbohydrate-rich foods to provide for considerably more. -using glucose to make fat after meeting its energy needs and filling its glyco- gen stores to capacity, the body must find a way to handle any extra glucose. -at first, energy metabolism shifts to use more glucose instead of fat. -if that isn t enough to restore glucose balance, the liver breaks glucose into smaller molecules and puts them together into the more permanent energy-storage compound fat. -thus when carbohydrate is abundant, fat is either conserved or created. -the fat then travels to the fatty tissues of the body for storage. -unlike the liver cells, which can store only enough glycogen to meet less than a day s energy needs, fat cells can store seem- ingly unlimited quantities of fat. -the constancy of blood glucose every body cell depends on glucose for its fuel to some extent, and the cells of the brain and the rest of the nervous system depend almost exclusively on glucose for their energy. -the activities of these cells never cease, and they have limited ability to store glucose. -day and night, they continually draw on the supply of glucose in the fluid surrounding them. -to maintain the supply, a steady stream of blood moves past these cells bringing more glucose from either the intestines (food) or the liver (via glycogen breakdown or gluconeogenesis). -maintaining glucose homeostasis to function optimally, the body must maintain blood glucose within limits that permit the cells to nourish themselves. -if blood glucose falls below normal, a person may become dizzy and weak; if it rises above normal, a person may become fatigued. -left untreated, fluctuations to the ex- tremes either high or low can be fatal. -the regulating hormones blood glucose homeostasis is regulated primarily by two hormones: insulin, which moves glucose from the blood into the cells, and glucagon, which brings glucose out of storage when necessary. -figure 4-12 (p. 114) de- picts these hormonal regulators at work. -after a meal, as blood glucose rises, special cells of the pancreas respond by se- creting insulin into the blood. -* in general, the amount of insulin secreted corre- sponds with the rise in glucose. -as the circulating insulin contacts the receptors on the body s other cells, the receptors respond by ushering glucose from the blood into the cells. -most of the cells take only the glucose they can use for energy right away, but the liver and muscle cells can assemble the small glucose units into long, branching chains of glycogen for storage. -the liver cells can also convert glucose to fat for export to other cells. -thus elevated blood glucose returns to normal levels as excess glucose is stored as glycogen and fat. -when blood glucose falls (as occurs between meals), other special cells of the pancreas respond by secreting glucagon into the blood. -** glucagon raises blood glucose by signaling the liver to break down its glycogen stores and release glucose into the blood for use by all the other body cells. -* the beta (bay-tuh) cells, one of several types of cells in the pancreas, secrete insulin in response to ele- vated blood glucose concentration. -** the alpha cells of the pancreas secrete glucagon in response to low blood glucose. -normal blood glucose (fasting): 70 to 100 mg/dl (published values vary slightly). -reminder: homeostasis is the maintenance of constant internal conditions by the body s con- trol systems. -ketone (kee-tone) bodies: the product of the incomplete breakdown of fat when glucose is not available in the cells. -ketosis (kee-toe-sis): an undesirably high concentration of ketone bodies in the blood and urine. -acid-base balance: the equilibrium in the body between acid and base concentrations (see chapter 12). -insulin (in-suh-lin): a hormone secreted by special cells in the pancreas in response to (among other things) increased blood glucose concentration. -the primary role of insulin is to control the transport of glucose from the bloodstream into the muscle and fat cells. -glucagon (gloo-ka-gon): a hormone that is secreted by special cells in the pancreas in response to low blood glucose concentration and elicits release of glucose from liver glycogen stores. -114 chapter 4 figure 4-12 maintaining blood glucose homeostasis blood vessel intestine 1 when a person eats, blood glucose rises. -pancreas fat cell pancreas key: insulin liver glucagon glucose insulin glucagon glycogen 2 high blood glucose stimulates the pancreas to release insulin. -3 insulin stimulates the uptake of glucose into cells and storage as glycogen in the liver and muscles. -insulin also stimulates the conversion of excess glucose into fat for storage. -muscle 4 as the body's cells use glucose, blood levels decline. -5 6 low blood glucose stimulates the pancreas to release glucagon into the bloodstream. -glucagon stimulates liver cells to break down glycogen and release glucose into the blood.a liver a the stress hormone epinephrine and other hormones also bring glucose out of storage. -7 blood glucose begins to rise. -another hormone that signals the liver cells to release glucose is the fight-or- flight hormone, epinephrine. -when a person experiences stress, epinephrine acts quickly, ensuring that all the body cells have energy fuel in emergencies. -among its many roles in the body, epinephrine works to release glucose from liver glycogen to the blood. -balancing within the normal range the maintenance of normal blood glu- cose ordinarily depends on two processes. -when blood glucose falls below normal, food can replenish it, or in the absence of food, glucagon can signal the liver to break down glycogen stores. -when blood glucose rises above normal, insulin can signal the cells to take in glucose for energy. -eating balanced meals at regular inter- vals helps the body maintain a happy medium between the extremes. -balanced meals that provide abundant complex carbohydrates, including fibers and a little fat, help to slow down the digestion and absorption of carbohydrate so that glucose enters the blood gradually, providing a steady, ongoing supply. -epinephrine (ep-ih-neff-rin): a hormone of the adrenal gland that modulates the stress response; formerly called adrenaline. -when administered by injection, epinephrine counteracts anaphylactic shock by opening the airways and maintaining heartbeat and blood pressure. -the carbohydrates: sugars, starches, and fibers 115 falling outside the normal range the influence of foods on blood glucose has given rise to the oversimplification that foods govern blood glucose concentrations. -foods do not; the body does. -in some people, however, blood glucose regulation fails. -when this happens, either of two conditions can result: diabetes or hypoglycemia. -people with these conditions often plan their diets to help maintain their blood glu- cose within a normal range. -diabetes in diabetes, blood glucose surges after a meal and remains above nor- mal levels because insulin is either inadequate or ineffective. -thus blood glucose is central to diabetes, but dietary carbohydrates do not cause diabetes. -there are two main types of diabetes. -in type 1 diabetes, the less common type, the pancreas fails to produce insulin. -although the exact cause is unclear, some research suggests that in genetically susceptible people, certain viruses ac- tivate the immune system to attack and destroy cells in the pancreas as if they were foreign cells. -in type 2 diabetes, the more common type of diabetes, the cells fail to respond to insulin. -this condition tends to occur as a consequence of obesity. -as the incidence of obesity in the united states has risen in recent decades, the incidence of diabetes has followed. -this trend is most notable among children and adolescents, as obesity among the nation s youth reaches epidemic proportions. -because obesity can precipitate type 2 diabetes, the best preventive measure is to maintain a healthy body weight. -concentrated sweets are not strictly excluded from the diabetic diet as they once were; they can be eaten in limited amounts with meals as part of a healthy diet. -chapter 15 de- scribes the type of diabetes that develops in some women during pregnancy (ges- tational diabetes), and chapter 18 gives full coverage to type 1 and type 2 diabetes and their associated problems. -hypoglycemia in healthy people, blood glucose rises after eating and then grad- ually falls back into the normal range. -the transition occurs without notice. -should blood glucose drop below normal, a person would experience the symptoms of hy- poglycemia: weakness, rapid heartbeat, sweating, anxiety, hunger, and trem- bling. -most commonly, hypoglycemia is a consequence of poorly managed diabetes. -too much insulin, strenuous physical activity, inadequate food intake, or illness that causes blood glucose levels to plummet. -hypoglycemia in healthy people is rare. -most people who experience hypo- glycemia need only adjust their diets by replacing refined carbohydrates with fiber- rich carbohydrates and ensuring an adequate protein intake. -in addition, smaller meals eaten more frequently may help. -hypoglycemia caused by certain medica- tions, pancreatic tumors, overuse of insulin, alcohol abuse, uncontrolled diabetes, or other illnesses requires medical intervention. -the glycemic response the glycemic response refers to how quickly glucose is absorbed after a person eats, how high blood glucose rises, and how quickly it returns to normal. -slow absorption, a modest rise in blood glucose, and a smooth return to normal are desirable (a low glycemic response). -fast absorption, a surge in blood glucose, and an overreaction that plunges glucose below normal are less desirable (a high glycemic response). -different foods have different effects on blood glucose. -the rate of glucose absorption is particularly important to people with dia- betes, who may benefit from limiting foods that produce too great a rise, or too sudden a fall, in blood glucose. -to aid their choices, they may be able to use the glycemic index, a method of classifying foods according to their potential to raise blood glucose. -figure 4-13 (p. 116) ranks selected foods by their glycemic index. -8 some studies have shown that selecting foods with a low glycemic index is a practical way to improve glucose control. -9 lowering the glycemic index of the diet may improve blood lipids and reduce the risk of heart disease as well.10 a low glycemic diet may also help with weight man- agement, although research findings are mixed.11 fibers and other slowly digested blood glucose (fasting): prediabetes: 100 to 125 mg/dl diabetes: (cid:4) 126 mg/dl the condition of having blood glucose levels higher than normal, but below the diagnosis of diabetes, is sometimes called prediabetes. -a related term, glycemic load, reflects both the glycemic index and the amount of carbohydrate. -diabetes (dye-uh-beet-eez): a chronic disorder of carbohydrate metabolism, usually resulting from insufficient or ineffective insulin. -type 1 diabetes: the less common type of diabetes in which the pancreas fails to produce insulin. -type 2 diabetes: the more common type of diabetes in which the cells fail to respond to insulin. -hypoglycemia (high-po-gly-see-me-ah): an abnormally low blood glucose concentration. -glycemic (gly-seem-ic) response: the extent to which a food raises the blood glucose concentration and elicits an insulin response. -glycemic index: a method of classifying foods according to their potential for raising blood glucose. -116 chapter 4 figure 4-13 glycemic index of selected foods s r a e p l , s e p p a , s n a e b y v a n , e c u i j o t a m o t e c u i j l e p p a s e h c a e p , s a e p d e y e - k c a b l l , s a e r e c n a r b i g n d d u p l , e t a o c o h c s e p a r g s n a e b d e k a b , s a e p n e e r g , s t o r r a c , i n o r a c a m e k a c d n u o p , n r o c , d a e r b t a e h w e c u i j e g n a r o , d a e r b e y r a n a n a b e c i r n w o r b s n a e b r e t t u b t r u g o y s n a e b o z n a b r a g , s n a e b y e n d k i , k l i m y e l r a b s e i r r e h c , s w e h s a c s n a e b y o s s t u n a e p low l e p p a e n p i l , a o c m a e r c e c i l e g a b , n r o c p o p l , n o e m r e t a w s n a e b y l l e j , s k n i r d s t r o p s t u n h g u o d i , n k p m u p o t a t o p d e k a b s e k a l f n r o c s u o c s u o c d a e r b e t i h w high e c i r e t i h w i , s n s a r i carbohydrates prolong the presence of foods in the digestive tract, thus providing greater satiety and diminishing the insulin response, which can help with weight control.12 in contrast, the rapid absorption of glucose from a high glycemic diet seems to increase the risk of heart disease and promote overeating in some over- weight people.13 despite these possible benefits, the usefulness of the glycemic index is sur- rounded by controversy as researchers debate whether selecting foods based on the glycemic index is practical or offers any real health benefits.14 those opposing the use of the glycemic index argue that it is not sufficiently supported by scientific re- search.15 the glycemic index has been determined for relatively few foods, and when the glycemic index has been established, it is based on an average of multi- ple tests with wide variations in their results. -values vary because of differences in the physical and chemical characteristics of foods, testing methods of laboratories, and digestive processes of individuals. -furthermore, the practical utility of the glycemic index is limited because this in- formation is neither provided on food labels nor intuitively apparent. -indeed, a food s glycemic index is not always what one might expect. -ice cream, for exam- ple, is a high-sugar food but produces less of a glycemic response than baked po- tatoes, a high-starch food. -this effect is most likely because the fat in the ice cream slows gi motility and thus the rate of glucose absorption. -mashed potatoes pro- duce more of a response than honey, probably because the fructose content of honey has little effect on blood glucose. -in fact, sugars such as fructose generally have a moderate to low glycemic index.16 perhaps most relevant to real life, a food s glycemic effect differs depending on plant variety, food processing, cooking method, and whether it is eaten alone or with other foods.17 most people eat a va- riety of foods, cooked and raw, that provide different amounts of carbohydrate, fat, and protein all of which influence the glycemic index of a meal. -paying attention to the glycemic index may not be necessary because current guidelines already suggest many low glycemic index choices: whole grains, legumes, vegetables, fruits, and milk products. -in addition, eating frequent, small meals spreads glucose absorption across the day and thus offers similar metabolic advantages to eating foods with a low glycemic response. -people want- ing to follow a low glycemic diet should be careful not to adopt a low carbohy- drate diet as well. -the problems associated with a low carbohydrate diet are addressed in highlight 9. the carbohydrates: sugars, starches, and fibers 117 in summary dietary carbohydrates provide glucose that can be used by the cells for energy, stored by the liver and muscles as glycogen, or converted into fat if intakes ex- ceed needs. -all of the body s cells depend on glucose; those of the central nerv- ous system are especially dependent on it. -without glucose, the body is forced to break down its protein tissues to make glucose and to alter energy metabo- lism to make ketone bodies from fats. -blood glucose regulation depends pri- marily on two pancreatic hormones: insulin to move glucose from the blood into the cells when levels are high and glucagon to free glucose from glycogen stores and release it into the blood when levels are low. -the glycemic index measures how blood glucose responds to foods. -health effects and recommended intakes of sugars ever since people first discovered honey and dates, they have enjoyed the sweetness of sugars. -in the united states, the natural sugars of milk, fruits, vegetables, and grains account for about half of the sugar intake; the other half consists of sugars that have been refined and added to foods for a variety of purposes. -the use of added sugars has risen steadily over the past several decades, both in the united states and around the world, with soft drinks and sugared fruit drinks accounting for most of the increase.18 these added sugars assume various names on food labels: su- crose, invert sugar, corn sugar, corn syrups and solids, high-fructose corn syrup, and honey. -a food is likely to be high in added sugars if its ingredient list starts with any of the sugars named in the glossary (p. 118) or if it includes sev- eral of them. -as an additive, sugar: enhances flavor supplies texture and color to baked goods provides fuel for fermentation, causing bread to rise or producing alcohol acts as a bulking agent in ice cream and baked goods acts as a preservative in jams balances the acidity of tomato- and vinegar-based products health effects of sugars in moderate amounts, sugars add pleasure to meals without harming health. -in excess, however, they can be detrimental in two ways. -one, sug- ars can contribute to nutrient deficiencies by supplying energy (kcalories) without providing nutrients. -two, sugars contribute to tooth decay. -nutrient deficiencies empty-kcalorie foods that contain lots of added sugar such as cakes, candies, and sodas deliver glucose and energy with few, if any, other nutrients. -by comparison, foods such as whole grains, veg- etables, legumes, and fruits that contain some natural sugars and lots of starches and fibers deliver protein, vitamins, and minerals along with their glucose and energy. -a person spending 200 kcalories of a day s energy allowance on a 16- ounce soda gets little of value for those kcaloric dollars. -in contrast, a per- son using 200 kcalories on three slices of whole-wheat bread gets 9 grams of protein, 6 grams of fiber, plus several of the b vitamins with those kcalories. -for the person who wants something sweet, a reasonable compromise might be two slices of bread with a teaspoon of jam on each. -the amount of sugar a person can afford to eat depends on how many kcalories are avail- able beyond those needed to deliver indispensable vitamins and minerals. -with careful food selections, a typical adult can obtain all the needed nu- trients within an allowance of about 1500 kcalories. -some people have more generous energy allowances with which to purchase nutrients. -for exam- ple, an active teenage boy may need as many as 3000 kcalories a day. -if he eats mostly nutritious foods, then the empty kcalories of cola beverages . -c n i s o i d u t s a r a l o p over half of the added sugars in our diet come from soft drinks and table sugar, but baked goods, fruit drinks, ice cream, candy, and breakfast cereals also make substantial contributions. -added sugars: sugars and syrups used as an ingredient in the processing and preparation of foods such as breads, cakes, beverages, jellies, and ice cream as well as sugars eaten separately or added to foods at the table. -118 chapter 4 g lossary of added sugars brown sugar: refined white sugar crystals to which manufacturers have added molasses syrup with natural flavor and color; 91 to 96% pure sucrose. -confectioners sugar: finely powdered sucrose, 99.9% pure. -corn sweeteners: corn syrup and sugars derived from corn. -corn syrup: a syrup made from cornstarch that has been treated with acid, high temperatures, and enzymes that produce glucose, maltose, and dextrins. -see also high-fructose corn syrup (hfcs). -dextrose: an older name for glucose. -granulated sugar: crystalline sucrose; 99.9% pure. -high-fructose corn syrup (hfcs): a syrup made from cornstarch that has been treated with an enzyme that converts some of the glucose to the sweeter fructose; made especially for use in processed foods and beverages, where it is the predominant sweetener. -with a chemical structure similar to sucrose, hfcs has a fructose content of 42, 55, or 90%, with glucose making up the remainder. -honey: sugar (mostly sucrose) formed from nectar gathered by bees. -an enzyme splits the sucrose into glucose and fructose. -composition and flavor vary, but honey always contains a mixture of sucrose, fructose, and glucose. -invert sugar: a mixture of raw sugar: the first crop of glucose and fructose formed by the hydrolysis of sucrose in a chemical process; sold only in liquid form and sweeter than sucrose. -invert sugar is used as a food additive to help preserve freshness and prevent shrinkage. -levulose: an older name for fructose. -maple sugar: a sugar (mostly sucrose) purified from the concentrated sap of the sugar maple tree. -molasses: the thick brown syrup produced during sugar refining. -molasses retains residual sugar and other by-products and a few minerals; blackstrap molasses contains significant amounts of calcium and iron. -crystals harvested during sugar processing. -raw sugar cannot be sold in the united states because it contains too much filth (dirt, insect fragments, and the like). -sugar sold as raw sugar domestically has actually gone through over half of the refining steps. -turbinado (ter-bih-nod-oh) sugar: sugar produced using the same refining process as white sugar, but without the bleaching and anti-caking treatment. -traces of molasses give turbinado its sandy color. -white sugar: pure sucrose or table sugar, produced by dissolving, concentrating, and recrystallizing raw sugar. -may be an acceptable addition to his diet. -in contrast, an inactive older woman who is limited to fewer than 1500 kcalories a day can afford to eat only the most nutrient- dense foods. -some people believe that because honey is a natural food, it is nutritious or, at least, more nutritious than sugar. -* a look at their chemical structures reveals the truth. -honey, like table sugar, contains glucose and fructose. -the primary differ- ence is that in table sugar the two monosaccharides are bonded together as a dis- accharide, whereas in honey some of them are free. -whether a person eats monosaccharides individually, as in honey, or linked together, as in table sugar, they end up the same way in the body: as glucose and fructose. -honey does contain a few vitamins and minerals, but not many, as table 4-1 shows. -honey is denser than crystalline sugar, too, so it provides more energy per spoonful. -* honey should never be fed to infants because of the risk of botulism. -chapters 16 and 19 provide more details. -table 4-1 sample nutrients in sugar and other foods the indicated portion of any of these foods provides approximately 100 kcalories. -notice that for a similar number of kcalories and grams of carbohydrate, milk, legumes, fruits, grains, and vegetables offer more of the other nutrients than do the sugars. -size of 100 kcal portion 1 c 1 2 c 6 11 2 slices 2 c 2 tbs 21 2 tbs 1 c 11 2 tbs foods milk, 1% low-fat kidney beans apricots bread, whole-wheat broccoli, cooked sugars sugar, white molasses, blackstrap cola beverage honey carbohydrate (g) protein (g) calcium (mg) iron (mg) vitamin a ( g) vitamin c (mg) 12 20 24 20 20 24 28 26 26 8 7 2 4 12 0 0 0 trace 300 30 30 30 188 trace 343 6 2 0.1 1.6 1.1 1.9 2.2 trace 12.6 trace 0.2 144 0 554 0 696 0 0 0 0 2 2 22 0 148 0 0.1 0 trace the carbohydrates: sugars, starches, and fibers 119 this is not to say that all sugar sources are alike, for some are more nutritious than others. -consider a fruit, say, an orange. -the fruit may give you the same amounts of fructose and glucose and the same number of kcalories as a dose of sugar or honey, but the packaging is more valuable nutritionally. -the fruit s sugars arrive in the body diluted in a large volume of water, packaged in fiber, and mixed with essential vitamins, minerals, and phytochemicals. -as these comparisons illustrate, the significant difference between sugar sources is not between natural honey and purified sugar but between concentrated sweets and the dilute, naturally occurring sugars that sweeten foods. -you can sus- pect an exaggerated nutrition claim when someone asserts that one product is more nutritious than another because it contains honey. -sugar can contribute to nutrient deficiencies only by displacing nutrients. -for nutrition s sake, the appropriate attitude to take is not that sugar is bad and must be avoided, but that nutritious foods must come first. -if nutritious foods crowd sugar out of the diet, that is fine but not the other way around. -as always, the goals to seek are balance, variety, and moderation. -dental caries sugars from foods and from the breakdown of starches in the mouth can contribute to tooth decay. -bacteria in the mouth ferment the sugars and, in the process, produce an acid that erodes tooth enamel (see figure 4-14), causing dental caries, or tooth decay. -people can eat sugar without this happening, though, for much depends on how long foods stay in the mouth. -sticky foods stay on the teeth longer and continue to yield acid longer than foods that are readily cleared from the mouth. -for that reason, sugar in a juice consumed quickly, for ex- ample, is less likely to cause dental caries than sugar in a pastry. -by the same token, the sugar in sticky foods such as dried fruits can be more detrimental than its quan- tity alone would suggest. -another concern is how often people eat sugar. -bacteria produce acid for 20 to 30 minutes after each exposure. -if a person eats three pieces of candy at one time, the teeth will be exposed to approximately 30 minutes of acid destruction. -but, if the person eats three pieces at half-hour intervals, the time of exposure increases to 90 minutes. -likewise, slowly sipping a sugary sports beverage may be more harm- ful than drinking quickly and clearing the mouth of sugar. -nonsugary foods can help remove sugar from tooth surfaces; hence, it is better to eat sugar with meals than between meals.19 foods such as milk and cheese may be particularly helpful in minimizing the effects of the acids and in restoring the lost enamel.20 beverages such as soft drinks, orange juice, and sports drinks not only contain sugar but also have a low ph. -these acidic drinks can erode tooth enamel and may explain why dental erosion is highly prevalent today.21 the development of caries depends on several factors: the bacteria that reside in dental plaque, the saliva that cleanses the mouth, the minerals that form the teeth, and the foods that remain after swallowing. -for most people, good oral hy- giene will prevent dental caries. -in fact, regular brushing (twice a day, with a flu- oride toothpaste) and flossing may be more effective in preventing dental caries than restricting sugary foods. -dietary guidelines for americans 2005 reduce the incidence of dental caries by practicing good oral hygiene and consuming sugar- and starch-containing foods and beverages less frequently. -figure 4-14 dental caries dental caries begins when acid dissolves the enamel that covers the tooth. -if not repaired, the decay may penetrate the dentin and spread into the pulp of the tooth, causing inflammation, abscess, and possible loss of the tooth. -enamel caries dentin gum pulp (blood vessels, nerves) bone root canal nerve crown blood vessel to prevent dental caries: limit between-meal snacks containing sug- ars and starches. -brush and floss teeth regularly. -if brushing and flossing are not possible, at least rinse with water. -controversies surrounding sugars sugars have been blamed for a variety of other health problems.22 the following paragraphs evaluate some of these controversies. -dental caries: decay of teeth. -caries = rottenness dental plaque: a gummy mass of bacteria that grows on teeth and can lead to dental caries and gum disease. -120 chapter 4 o i g g u r r a f w e h t t a m you receive about the same amount and kinds of sugars from an orange as from a tablespoon of honey, but the packaging makes a big nutrition difference. -serotonin (ser-oh-tone-in): a neurotransmitter important in sleep regulation, appetite control, intestinal motility, obsessive-compulsive behaviors, and mood disorders. -controversy: does sugar cause obesity? -over the past three decades, obe- sity rates have risen sharply in the united states. -during the same period, consump- tion of added sugars has reached an all-time high much of it because of the dramatic rise in high-fructose corn syrup used in beverages. -between 1977 and 2001, as people grew fatter, their intake of kcalories from fruit drinks and punches doubled and kcalories from soft drinks nearly tripled.23 although the use of this sweetener parallels unprecedented gains of body fatness, does it mean that the in- creasing sugar intakes are responsible for the increase in obesity? -24 when eaten in excess of need, energy from added sugars contributes to body fat stores, just as excess energy from other sources does. -added sugars provide excess kcalories, raising the risk of weight gain and type 2 diabetes.25 when total kcalorie intakes are controlled, however, moderate amounts of sugar do not cause obesity.26 people with diets high in added sugars often consume more kcalories each day than people with lower sugar intakes. -adolescents, for example, who drink as much as 26 ounces or more (about two cans) of sugar-sweetened soft drinks daily, consume 400 more kcalories a day than teens who don t. overweight children and adolescents increase their risk of becoming obese by 60 percent with each addi- tional syrup-sweetened drink they add to their daily diet. -the liquid form of sugar in soft drinks makes it especially easy to overconsume kcalories.27 investigators are evaluating these and other possible links between fructose in the syrupy sweeteners of soft drinks and weight gain.28 research suggests that fructose from these added sugars favors the fat-making pathways.29 limiting selections of foods and beverages high in added sugars can be an effec- tive weight-loss strategy, especially for people whose excess kcalories come prima- rily from added sugars.30 replacing a can of cola with a glass of water every day, for example, can help a person lose a pound (or at least not gain a pound) in one month. -that may not sound like much, but it adds up to more than 10 pounds a year, for very little effort. -controversy: does sugar cause heart disease? -a diet high in added sugars can alter blood lipids to favor heart disease.31 (lipids include fats and cholesterol, as chapter 5 explains.) -this effect is most dramatic in people who respond to sucrose with abnormally high insulin secretions, which promote the making of excess fat.32 for most people, though, moderate sugar intakes do not elevate blood lipids. -to keep these findings in perspective, consider that heart disease correlates most closely with factors that have nothing to do with nutrition, such as smoking and genetics. -among dietary risk factors, several such as saturated fats, trans fats, and choles- terol have much stronger associations with heart disease than do sugar intakes. -controversy: does sugar cause misbehavior in children and criminal be- havior in adults? -sugar has been blamed for the misbehaviors of hyperactive children, delinquent adolescents, and lawbreaking adults. -such speculations have been based on personal stories and have not been confirmed by scientific research. -no scientific evidence supports a relationship between sugar and hyperactivity or other misbehaviors. -chapter 16 provides accurate information on diet and chil- dren s behavior. -controversy: does sugar cause cravings and addictions? -foods in gen- eral, and carbohydrates and sugars more specifically, are not physically addictive in the ways that drugs are. -yet some people describe themselves as having carbohy- drate cravings or being sugar addicts. -one frequently noted theory is that people seek carbohydrates as a way to increase their levels of the brain neurotransmitter serotonin, which elevates mood. -interestingly, when those with self-described car- bohydrate cravings indulge, they tend to eat more of everything, but the percentage of energy from carbohydrates remains unchanged.33 alcohol also raises serotonin levels, and alcohol-dependent people who crave carbohydrates seem to handle so- briety better when given a high-carbohydrate diet. -one reasonable explanation for the carbohydrate cravings that some people ex- perience involves the self-imposed labeling of a food as both good and bad that is, one that is desirable but should be eaten with restraint. -chocolate is a familiar ex- the carbohydrates: sugars, starches, and fibers 121 ample. -restricting intake heightens the desire further (a craving ). -then addiction is used to explain why resisting the food is so difficult and, sometimes, even impossi- ble. -but the addiction is not pharmacological; a capsule of the psychoactive sub- stances commonly found in chocolate, for example, does not satisfy the craving. -recommended intakes of sugars because added sugars deliver kcalories but few or no nutrients, the 2005 dietary guidelines urge consumers to choose and prepare foods and beverages with little added sugars. -the usda food guide counts these sugar kcalories (and those from solid fats and alcohol) as discretionary kcalories. -most people need to limit their use of added sugars. -estimates indicate that, on average, each person in the united states consumes about 105 pounds (almost 50 kilograms) of added sugar per year, or about 30 teaspoons (about 120 grams) of added sugar a day, an amount that ex- ceeds these guidelines.34 dietary guidelines for americans 2005 choose and prepare foods and beverages with little added sugars. -estimating the added sugars in a diet is not always easy for consumers. -food la- bels list the total grams of sugar a food provides, but this total reflects both added sugars and those occurring naturally in foods. -to help estimate sugar and energy intakes accurately, the list in the margin shows the amounts of concentrated sweets that are equivalent to 1 teaspoon of white sugar. -these sugars all provide about 5 grams of carbohydrate and about 20 kcalories per teaspoon. -some are lower (16 kcalories for table sugar), and others are higher (22 kcalories for honey), but a 20-kcalorie average is an acceptable approximation. -for a person who uses catsup liberally, it may help to remember that 1 tablespoon of catsup supplies about 1 teaspoon of sugar. -the dri committee did not set an upper level for sugar, but as mentioned, exces- sive intakes can interfere with sound nutrition and dental health. -few people can eat lots of sugary treats and still meet all of their nutrient needs without exceeding their kcalorie allowance. -specifically, the dri suggests that added sugars should ac- count for no more than 25 percent of the day s total energy intake.35 when added sugars occupy this much of a diet, however, intakes from the five food groups fall below recommendations. -for a person consuming 2000 kcalories a day, 25 percent represents 500 kcalories (that is, 125 grams, or 31 teaspoons) from concentrated sugars and that s a lot of sugar. -perhaps an athlete in training whose energy needs are high can afford the added sugars from sports drinks without compromis- ing nutrient intake, but most people do better by limiting their use of added sugars. -the world health organization (who) and the food and agriculture organiza- tion (fao) suggest restricting consumption of added sugars to less than 10 percent of total energy. -in summary sugars pose no major health threat except for an increased risk of dental caries. -excessive intakes, however, may displace needed nutrients and fiber and may contribute to obesity when energy intake exceeds needs. -a person de- ciding to limit daily sugar intake should recognize that not all sugars need to be restricted, just concentrated sweets, which are relatively empty of other nu- trients and high in kcalories. -sugars that occur naturally in fruits, vegetables, and milk are acceptable. -usda food guide amounts of added sugars that can be included as discretionary kcalories when food choices are nutrient dense and fat (cid:5) 30% total kcal: 3 tsp for 1600 kcal diet 5 tsp for 1800 kcal diet 8 tsp for 2000 kcal diet 9 tsp for 2200 kcal diet 12 tsp for 2400 kcal diet 1 tsp white sugar = 1 tsp brown sugar 1 tsp candy 1 tsp corn sweetener or corn syrup 1 tsp honey 1 tsp jam or jelly 1 tsp maple sugar or maple syrup 1 tsp molasses 11/2 oz carbonated soda 1 tbs catsup for perspective, each of these concentrated sugars provides about 500 kcal: 40 oz cola 1/2 c honey 125 jelly beans 23 marshmallows 30 tsp sugar how many kcalories from sugar does your favorite beverage or snack provide? -122 chapter 4 foods rich in starch and fiber offer many health benefits. -consuming 5 to 10 g of soluble fiber daily re- duces blood cholesterol by 3 to 5%. -for perspective, 1/2 c dry oat bran provides 8 g of fiber, and 1 c cooked barley or 1/2 c cooked legumes provides about 6 g of fiber. -s e g a m i y t t e g / k n a b e g a m i e h t / s s a m a t i r health effects and recommended intakes of starch and fibers carbohydrates and fats are the two major sources of energy in the diet. -when one is high, the other is usually low and vice versa. -a diet that provides abundant carbo- hydrate (45 to 65 percent of energy intake) and some fat (20 to 35 percent of energy intake) within a reasonable energy allowance best supports good health. -to increase carbohydrate in the diet, focus on whole grains, vegetables, legumes, and fruits foods noted for their starch, fibers, and naturally occurring sugars. -health effects of starch and fibers in addition to starch, fibers, and natural sugars, whole grains, vegetables, legumes, and fruits supply valuable vitamins and minerals and little or no fat. -the following paragraphs describe some of the health benefits of diets that include a variety of these foods daily. -heart disease high-carbohydrate diets, especially those rich in whole grains, may protect against heart disease and stroke, although sorting out the exact reasons why can be difficult.36 such diets are low in animal fat and cholesterol and high in fibers, vegetable proteins, and phytochemicals all factors associated with a lower risk of heart disease. -(the role of animal fat and cholesterol in heart disease is dis- cussed in chapter 5. the role of vegetable proteins in heart disease is presented in chapter 6. the benefits of phytochemicals in disease prevention are featured in highlight 13.) -foods rich in soluble fibers (such as oat bran, barley, and legumes) lower blood cholesterol by binding with bile acids and thereby increasing their excretion. -consequently, the liver must use its cholesterol to make new bile acids. -in addition, the bacterial by-products of fiber fermentation in the colon also inhibit cholesterol synthesis in the liver. -the net result is lower blood cholesterol.37 several researchers have speculated that fiber may also exert its effect by dis- placing fats in the diet. -whereas this is certainly helpful, even when dietary fat is low, high intakes of fibers exert a separate and significant cholesterol-lowering ef- fect. -in other words, a high-fiber diet helps to decrease the risk of heart disease inde- pendent of fat intake.38 diabetes high-fiber foods especially whole grains play a key role in reducing the risk of type 2 diabetes.39 when soluble fibers trap nutrients and delay their transit through the gi tract, glucose absorption is slowed, which helps to prevent the glucose surge and rebound that seem to be associated with diabetes onset. -gi health dietary fibers enhance the health of the large intestine. -the healthier the intestinal walls, the better they can block absorption of unwanted constituents. -fibers such as cellulose (as in cereal brans, fruits, and vegetables) increase stool weight, easing passage, and reduce transit time. -in this way, the fibers help to alle- viate or prevent constipation. -taken with ample fluids, fibers help to prevent several gi disorders. -large, soft stools ease elimination for the rectal muscles and reduce the pressure in the lower bowel, making it less likely that rectal veins will swell (hemorrhoids). -fiber prevents compaction of the intestinal contents, which could obstruct the appendix and per- mit bacteria to invade and infect it (appendicitis). -in addition, fiber stimulates the gi tract muscles so that they retain their strength and resist bulging out into pouches known as diverticula (illustrated in figure h3-3 on p. 95).40 cancer many, but not all, research studies suggest that increasing dietary fiber protects against colon cancer.41 when the largest study of diet and cancer to date examined the diets of over a half million people in ten countries for four and a half the carbohydrates: sugars, starches, and fibers 123 years, the researchers found an inverse association between dietary fiber and colon cancer.42 people who ate the most dietary fiber (35 grams per day) reduced their risk of colon cancer by 40 percent compared with those who ate the least fiber (15 grams per day). -importantly, the study focused on dietary fiber, not fiber supple- ments or additives, which lack valuable nutrients and phytochemicals that also help protect against cancer. -plant foods vegetables, fruits, and whole-grain prod- ucts reduce the risks of colon and rectal cancers.43 fibers may help prevent colon cancer by diluting, binding, and rapidly remov- ing potential cancer-causing agents from the colon. -in addition, soluble fibers stim- ulate bacterial fermentation of resistant starch and fiber in the colon, a process that produces short-chain fatty acids that lower the ph. -these small fat molecules acti- vate cancer-killing enzymes and inhibit inflammation in the colon.44 weight management high-fiber and whole-grain foods help a person to main- tain a healthy body weight.45 foods rich in complex carbohydrates tend to be low in fat and added sugars and can therefore promote weight loss by delivering less energy per bite. -in addition, as fibers absorb water from the digestive juices, they swell, creating feelings of fullness and delaying hunger. -many weight-loss products on the market today contain bulk-inducing fibers such as methylcellulose, but buying pure fiber compounds like this is neither nec- essary nor advisable. -most experts agree that the health and weight management benefits attributed to fiber may come from other constituents of fiber-containing foods, and not from fiber alone.46 for this reason, consumers should select whole grains, legumes, fruits, and vegetables instead of fiber supplements. -high-fiber foods not only add bulk to the diet but are economical and nutritious as well. -table 4-2 summarizes fibers and their health benefits. -harmful effects of excessive fiber intake despite fibers benefits to health, a diet high in fiber also has a few drawbacks. -a person who has a small capacity and eats mostly high-fiber foods may not be able to take in enough food to meet energy or nutrient needs. -the malnourished, the elderly, and young children adhering to all-plant (vegan) diets are especially vulnerable to this problem. -launching suddenly into a high-fiber diet can cause temporary bouts of abdom- inal discomfort, gas, and diarrhea and, more seriously, can obstruct the gi tract. -to reminder: carbohydrate: 4 kcal/g fat: 9 kcal/g table 4-2 dietary fibers: their characteristics, food sources, and health effects in the body fiber characteristics major food sources actions in the body health benefits soluble, viscous, more fermentable gums and mucilages pectins psylliuma some hemicelluloses insoluble, nonviscous, less fermentable cellulose lignins psylliuma resistant starch many hemicelluloses whole-grain products (barley, oats, oat bran, rye), fruits (apples, citrus), legumes, seeds and husks, vegeta- bles; also extracted and used as food additives lower blood cholesterol by binding bile slow glucose absorption slow transit of food through upper gi tract hold moisture in stools, soften- ing them yield small fat molecules after fermentation that the colon can use for energy lower risk of heart disease lower risk of diabetes brown rice, fruits, legumes, seeds, vegetables (cabbage, carrots, brussels sprouts), wheat bran, whole grains; also extracted and used as food additives increase fecal weight and speed fecal passage through colon provide bulk and feelings of alleviate constipation lower risks of diverticulosis, hemorrhoids, and appendicitis fullness may help with weight management apsyllium, a fiber laxative and cereal additive, has both soluble and insoluble properties. -124 chapter 4 prevent such complications, a person adopting a high-fiber diet can take the fol- lowing precautions: increase fiber intake gradually over several weeks to give the gi tract time to adapt. -drink plenty of liquids to soften the fiber as it moves through the gi tract. -select fiber-rich foods from a variety of sources fruits, vegetables, legumes, and whole-grain breads and cereals. -some fibers can limit the absorption of nutrients by speeding the transit of foods through the gi tract and by binding to minerals. -when mineral intake is adequate, however, a reasonable intake of high-fiber foods does not seem to compromise mineral balance. -clearly, fiber is like all the nutrients in that more is better only up to a point. -again, the key words are balance, moderation, and variety. -in summary adequate intake of fiber: fosters weight management lowers blood cholesterol may help prevent colon cancer helps prevent and control diabetes helps prevent and alleviate hemorrhoids helps prevent appendicitis helps prevent diverticulosis excessive intake of fiber: displaces energy- and nutrient-dense foods causes intestinal discomfort and distention may interfere with mineral absorption the aids to calculations section at the end of this book explains how to solve such problems. -rda for carbohydrate: 130 g/day 45 to 65% of energy intake daily value: 300 g carbohydrate (based on 60% of 2000 kcal diet) to increase your fiber intake: eat whole-grain cereals that contain (cid:4) 5 g fiber per serving for breakfast. -eat raw vegetables. -eat fruits (such as pears) and vegetables (such as potatoes) with their skins. -add legumes to soups, salads, and casseroles. -eat fresh and dried fruit for snacks. -daily value: 25 g fiber (based on 11.5 g/1000 kcal) recommended intakes of starch and fibers dietary recommendations suggest that carbohydrates provide about half (45 to 65 percent) of the energy requirement. -a person consuming 2000 kcalories a day should therefore have 900 to 1300 kcalories of carbohydrate, or about 225 to 325 grams. -this amount is more than adequate to meet the rda for carbohydrate, which is set at 130 grams per day, based on the average minimum amount of glu- cose used by the brain.47 when it established the daily values that appear on food labels, the food and drug administration (fda) used a 60 percent of kcalories guideline in setting the daily value for carbohydrate at 300 grams per day. -for most people, this means increasing total carbohydrate intake. -to this end, the dietary guidelines encourage people to choose a variety of whole grains, vegetables, fruits, and legumes daily. -dietary guidelines for americans 2005 choose fiber-rich fruits, vegetables, and whole grains often. -recommendations for fiber suggest the same foods just mentioned: whole grains, vegetables, fruits, and legumes, which also provide minerals and vitamins. -the fda set the daily value for fiber at 25 grams, rounding up from the recom- the carbohydrates: sugars, starches, and fibers 125 . -c n i , s o i d u t s a r a l o p . -c n i , s o i d u t s a r a l o p . -c n i , s o i d u t s a r a l o p / e u l b c s i d o t o h p s e g a m i y t t e g table 4-3 fiber in selected foods grains whole-grain products provide about 1 to 2 grams (or more) of fiber per serving: 1 slice whole-wheat, pumpernickel, rye bread 1 oz ready-to-eat cereal (100% bran cereals contain 10 grams or more) 1 2 c cooked barley, bulgur, grits, oatmeal vegetable most vegetables contain about 2 to 3 grams of fiber per serving: 1 c raw bean sprouts 1 2 c cooked broccoli, brussels sprouts, cabbage, carrots, cauliflower, collards, corn, eggplant, green beans, green peas, kale, mushrooms, okra, parsnips, potatoes, pumpkin, spinach, sweet potatoes, swiss chard, winter squash 1 2 c chopped raw carrots, peppers fruit fresh, frozen, and dried fruits have about 2 grams of fiber per serving: 1 medium apple, banana, kiwi, nectarine, orange, pear 1 2 c applesauce, blackberries, blueberries, raspberries, strawberries fruit juices contain very little fiber legumes many legumes provide about 6 to 8 grams of fiber per serving: 1 2 c cooked baked beans, black beans, black-eyed peas, kidney beans, navy beans, pinto beans some legumes provide about 5 grams of fiber per serving: 1 2 c cooked garbanzo beans, great northern beans, lentils, lima beans, split peas note: appendix h provides fiber grams for over 2000 foods. -mended 11.5 grams per 1000-kcalories for a 2000-kcalorie intake. -the dri recom- mendation is slightly higher, at 14 grams per 1000-kcalorie intake. -similarly, the american dietetic association suggests 20 to 35 grams of dietary fiber daily, which is about two times higher than the average intake in the united states.48 an effec- tive way to add fiber while lowering fat is to substitute plant sources of proteins (legumes) for animal sources (meats). -table 4-3 presents a list of fiber sources. -as mentioned earlier, too much fiber is no better than too little. -the world health organization recommends an upper limit of 40 grams of dietary fiber a day. -from guidelines to groceries a diet following the usda food guide, which includes several servings of fruits, veg- etables, and grains daily, can easily supply the recommended amount of carbohy- drates and fiber. -in selecting high-fiber foods, keep in mind the principle of variety. -the fibers in oats lower cholesterol, whereas those in bran help promote gi tract health. -(review table 4-2 to see the diverse health effects of various fibers.) -grains an ounce-equivalent of most foods in the grain group provides about 15 grams of carbohydrate, mostly as starch. -be aware that some foods in this group, especially snack crackers and baked goods such as biscuits, croissants, and muffins, contain added sugars, added fat, or both. -when selecting from the grain group, be sure to include at least half as whole-grain products (see figure 4-15, p. 126). -the 3 are key message may help consumers to remember to choose a whole-grain cereal for breakfast, a whole-grain bread for lunch, and a whole- grain pasta or rice for dinner. -126 chapter 4 figure 4-15 bread labels compared food labels list the quantities of total carbohydrate, dietary fiber, and sugars. -total carbohydrate and dietary fiber are also stated as % daily values. -a close look at these two labels reveals that bread made from whole wheat-flour provides almost three times as much fiber as the one made mostly from refined wheat flour. -when the words whole wheat or whole grain appear on the label, the bread inside contains all of the nutrients that bread can provide. -nutrition facts serving size 1 slice (30g) servings per container 15 nutrition facts serving size 1 slice (30g) servings per container 15 amount per serving amount per serving calories 90 calories from fat 14 calories 90 calories from fat 14 % daily value* % daily value* total fat 1.5g sodium 135mg total carbohydrate 15g dietary fiber 2g sugars 2g protein 4g 2% 6% 5% 8% total fat 1.5g sodium 220mg total carbohydrate 15g dietary fiber less than 1g 2% 9% 5% 2% sugars 2g protein 4g made from: unbromated stone ground 100% whole wheat flour, water, crushed wheat, high fructose corn syrup, partially hydrogenated vegetable shortening (soybean and cottonseed juice concentrate, wheat gluten, yeast, whole wheat flakes, unsulphured molasses, salt, honey, vinegar, lecithin, enzyme modified cultured whey, unbleached wheat flour and soy lecithin. -raisin oils), soy iron, reduced ingredients: unbleached enriched wheat flour [malted barley flour, thiamin niacin, mononitrate (vitamin b1), riboflavin (vitamin b2), folic acid], water, high fructose corn syrup, molasses, partially hydrogenated soybean oil, yeast, corn flour, salt, ground caraway, wheat gluten, calcium propionate (preservative), monoglycerides, soy lecithin. -vegetables the amount of carbohydrate a serving of vegetables provides depends primarily on its starch content. -starchy vegetables a half-cup of cooked corn, peas, or potatoes provide about 15 grams of carbohydrate per serving. -a serving of most other nonstarchy vegetables such as a half-cup of broccoli, green beans, or toma- toes provides about 5 grams. -fruits a typical fruit serving a small banana, apple, or orange or a half-cup of most canned or fresh fruit contains an average of about 15 grams of carbohydrate, mostly as sugars, including the fruit sugar fructose. -fruits vary greatly in their water and fiber contents and, therefore, in their sugar concentrations. -milks and milk products a serving (a cup) of milk or yogurt provides about 12 grams of carbohydrate. -cottage cheese provides about 6 grams of carbohydrate per cup, but most other cheeses contain little, if any, carbohydrate. -meats and meat alternates with two exceptions, foods in the meats and meat alternates group deliver almost no carbohydrate to the diet. -the exceptions are nuts, which provide a little starch and fiber along with their abundant fat, and legumes, which provide an abundance of both starch and fiber. -just a half-cup serving of legumes provides about 20 grams of carbohydrate, a third from fiber. -read food labels food labels list the amount, in grams, of total carbohydrate including starch, fibers, and sugars per serving (review figure 4-15). -fiber grams are also listed separately, as are the grams of sugars. -(with this information, you can calculate starch grams by subtracting the grams of fibers and sugars from the to- tal carbohydrate.) -sugars reflect both added sugars and those that occur naturally in foods. -total carbohydrate and dietary fiber are also expressed as % daily values for a person consuming 2000 kcalories; there is no daily value for sugars. -to calculate starch grams using the first label in figure 4-15: 15 g total 4 g (dietary fiber + sugars) = 11 g starch the carbohydrates: sugars, starches, and fibers 127 in summary clearly, a diet rich in complex carbohydrates starches and fibers supports efforts to control body weight and prevent heart disease, cancer, diabetes, and gi disorders. -for these reasons, recommendations urge people to eat plenty of whole grains, vegetables, legumes, and fruits enough to provide 45 to 65 per- cent of the daily energy intake from carbohydrate. -in today s world, there is one other reason why plant foods rich in complex carbohy- drates and natural sugars are a better choice than animal foods or foods high in concentrated sweets: in general, less energy and fewer resources are required to grow and process plant foods than to produce sugar or foods derived from animals. -chap- ter 20 takes a closer look at the environmental impacts of food production and use. -nutrition portfolio www.thomsonedu.com/thomsonnow foods that derive from plants whole grains, vegetables, legumes, and fruits naturally provide ample carbohydrates and fiber with little or no fat. -refined foods often contain added sugars and fat. -list the types and amounts of grain products you eat daily, making note of which are whole-grain or refined foods and how your choices could include more whole-grain options. -list the types and amounts of fruits and vegetables you eat daily, making note of how many are dark-green, orange, or deep yellow, how many are starchy or legumes, and how your choices could include more of these options. -describe choices you can make in selecting and preparing foods and bever- ages to lower your intake of added sugars. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 4, then to nutrition on the net. -search for lactose intolerance at the u.s. government health information site: www.healthfinder.gov search for sugars and fiber at the international food information council site: www.ific.org learn more about dental caries from the american dental association and the national institute of dental and craniofacial research: www.ada.org and www.nidcr.nih.gov learn more about diabetes from the american diabetes association, the canadian diabetes association, and the national institute of diabetes and digestive and kidney diseases: www.diabetes.org, www.diabetes.ca, and www.niddk.nih.gov 128 chapter 4 nutrition calculations for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 4, then to nutrition calculations. -these problems will give you practice in doing simple nutrition-related calculations. -although the situations are hypothetical, the numbers are real, and calculating the answers (check them on p. 131) provides a valuable lesson. -be sure to show your calculations for each problem. -health recommendations suggest that 45 to 65 percent of the daily energy intake come from carbohydrates. -stating recommendations in terms of percentage of energy intake is meaningful only if energy intake is known. -the following exercises illustrate this concept. -1. calculate the carbohydrate intake (in grams) for a stu- dent who has a high carbohydrate intake (70 percent of energy intake) and a moderate energy intake (2000 kcalories a day). -how does this carbohydrate intake compare to the daily value of 300 grams? -to the 45 to 65 percent recommendation? -2. now consider a professor who eats half as much carbohy- drate as the student (in grams) and has the same energy intake. -what percentage does carbohydrate contribute to the daily intake? -study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review this chapter. -you will find the answers in the discussions on the pages provided. -1. which carbohydrates are described as simple and which are complex? -(p. 101) 2. describe the structure of a monosaccharide and name the three monosaccharides important in nutrition. -name the three disaccharides commonly found in foods and their component monosaccharides. -in what foods are these sugars found? -(pp. -102 105) 3. what happens in a condensation reaction? -in a hydroly- sis reaction? -(p. 104) 4. describe the structure of polysaccharides and name the ones important in nutrition. -how are starch and glyco- gen similar, and how do they differ? -how do the fibers differ from the other polysaccharides? -(pp. -105 107) 5. describe carbohydrate digestion and absorption. -what role does fiber play in the process? -(pp. -107 110) 6. what are the possible fates of glucose in the body? -what is the protein-sparing action of carbohydrate? -(pp. -111 113) 7. how does the body maintain its blood glucose concen- tration? -what happens when the blood glucose concen- tration rises too high or falls too low? -(pp. -113 117) how does carbohydrate intake compare to the daily value of 300 grams? -to the 45 to 65 percent recommendation? -3. now consider an athlete who eats twice as much carbohy- drate (in grams) as the student and has a much higher energy intake (6000 kcalories a day). -what percentage does carbohydrate contribute to this person s daily intake? -how does carbohydrate intake compare to the daily value of 300 grams? -to the 45 to 65 percent recommendation? -4. one more example. -in an attempt to lose weight, a per- son adopts a diet that provides 150 grams of carbohy- drate per day and limits energy intake to 1000 kcalories. -what percentage does carbohydrate contribute to this person s daily intake? -how does this carbohydrate intake compare to the daily value of 300 grams? -to the 45 to 65 percent recommendation? -these exercises should convince you of the importance of ex- amining actual intake as well the percentage of energy intake. -8. what are the health effects of sugars? -what are the di- etary recommendations regarding concentrated sugar intakes? -(pp. -117 121) 9. what are the health effects of starches and fibers? -what are the dietary recommendations regarding these com- plex carbohydrates? -(pp. -122 125) 10. what foods provide starches and fibers? -(pp. -125 126) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 131. -1. carbohydrates are found in virtually all foods except: a. milks. -b. meats. -c. breads. -d. fruits. -2. disaccharides include: a. starch, glycogen, and fiber. -b. amylose, pectin, and dextrose. -c. sucrose, maltose, and lactose. -d. glucose, galactose, and fructose. -3. the making of a disaccharide from two monosaccharides is an example of: a. digestion. -b. hydrolysis. -c. condensation. -d. gluconeogenesis. -the carbohydrates: sugars, starches, and fibers 129 4. the storage form of glucose in the body is: 8. with insufficient glucose in metabolism, fat fragments a. insulin. -b. maltose. -c. glucagon. -d. glycogen. -5. the significant difference between starch and cellulose is that: a. starch is a polysaccharide, but cellulose is not. -b. animals can store glucose as starch, but not as cellulose. -c. hormones can make glucose from cellulose, but not from starch. -combine to form: a. dextrins. -b. mucilages. -c. phytic acids. -d. ketone bodies. -9. what does the pancreas secrete when blood glucose rises? -when blood glucose falls? -a. insulin; glucagon b. glucagon; insulin c. insulin; glycogen d. glycogen; epinephrine d. digestive enzymes can break the bonds in starch, 10. what percentage of the daily energy intake should come but not in cellulose. -6. the ultimate goal of carbohydrate digestion and absorp- tion is to yield: a. fibers. -b. glucose. -c. enzymes. -d. amylase. -7. the enzyme that breaks a disaccharide into glucose and from carbohydrates? -a. -15 to 20 b. -25 to 30 c. 45 to 50 d. 45 to 65 galactose is: a. amylase. -b. maltase. -c. sucrase. -d. lactase. -references 1. n. r. sahyoan and coauthors, whole-grain intake is inversely associated with metabolic syndrome and mortality in older adults, american journal of clinical nutrition 83 (2006): 124-131; b. m. 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ldl-cholesterol subclass and particle numbers in middle-aged and older men, american journal of clinical nutrition 76 (2002): 351-358; d. j. a. jenkins and coau- thors, soluble fiber intake at a dose approved by the us food and drug administration for a claim of health benefits: serum lipid risk factors for cardiovascular disease assessed in a randomized controlled crossover trial, american journal of clinical nutrition 75 (2002): 834-839. -38. u. a. ajani, e. s. ford, and a. h. mokdad, dietary fiber and c-reactive protein: find- ings from national health and nutrition examination survey data, journal of nutri- tion 134 (2004): 1181-1185. -39. m. k. jenson and coauthors, whole grains, bran and germ in relation to homocysteine and markers of glycemic control, lipids, and inflammation, american journal of clinical nutrition 83 (2006): 275-283; t. t. fung and coauthors, whole-grain intake and the risk of type 2 diabetes: a prospec- tive study in men, american journal of clinical nutrition 76 (2002): 535-540. -40. w. aldoori and m. ryan-harshman, pre- venting diverticular disease: review of recent evidence on high-fibre diets, canadian family physician 48 (2002): 1632-1637. -41. y. park and coauthors, dietary fiber intake and risk of colorectal cancer, journal of the american medical association 294 (2005): 2849-2857; t. asano and r. s. mcleod, dietary fibre for the prevention of colorec- tal adenomas and carcinomas, cochrane database of systematic reviews 2 (2002): cd003430. -42. s. a. bingham and coauthors, dietary fibre in food and protection against colorectal cancer in the european prospective investi- gation into cancer and nutrition (epic): an observational study, lancet 361 (2003): 1496-1501. -43. m. l. slattery and coauthors, plant foods, fiber, and rectal cancer, american journal of clinical nutrition 79 (2004): 274-281. -44. l. mcmillan and coauthors, opposing effects of butyrate and bile acids on apop- tosis of human colon adenoma cells: differential activation of pkc and map kinases, british journal of cancer 88 (2003): 748-753; m. e. rodriguez-cabezas and coauthors, dietary fiber down-regulates colonic tumor necrosis factor alpha and nitric oxide production in trinitrobenzene- sulfonic acid-induced colitic rats, journal of nutrition 11 (2002): 3263-3271. -45. s. liu and coauthors, relation between changes in intakes of dietary fiber and grain products and changes in weight and development of obesity among middle- aged women, american journal of clinical nutrition 78 (2003): 920-927. -46. p. koh-banerjee, changes in whole-grain, bran, and cereal fiber consumption in relation to 8-y weight gain among men, american journal of clinical nutrition 80 (2004): 1237-1245; committee on dietary reference intakes, 2002/2005, pp. -342-344. -47. committee on dietary reference intakes, 2005. -48. position of the american dietetic associa- tion: health implications of dietary fiber, journal of the american dietetic association 102 (2002): 993-999. the carbohydrates: sugars, starches, and fibers 131 this carbohydrate intake is higher than the daily value and meets the 45 to 65 percent recommendation. -4. -150 g carbohydrate (cid:6) 4 kcal/g (cid:7) 600 kcal from carbohydrate 600 kcal from carbohydrate (cid:8) 1000 total kcal/day (cid:7) 0.60 0.60 (cid:6) 100 (cid:7) 60% kcal from carbohydrate this carbohydrate intake is lower than the daily value and meets the 45 to 65 percent recommendation. -study questions (multiple choice) 1. b 6. b 2. c 7. d 3. c 8. d 4. d 9. a 5. d 10. d answers nutrition calculations 1. -0.7 (cid:6) 2000 total kcal/day (cid:7) 1400 kcal from carbohydrate/day 1400 kcal from carbohydrate (cid:8) 4 kcal/g (cid:7) 350 g carbohydrate this carbohydrate intake is higher than the daily value and higher than the 45 to 65 percent recommendation. -2. -350 g carbohydrate (cid:8) 2 (cid:7) 175 g carbohydrate/day 175 g carbohydrate (cid:6) 4 kcal/g (cid:7) 700 kcal from carbohydrate 700 kcal from carbohydrate (cid:8) 2000 total kcal/day (cid:7) 0.35 0.35 (cid:6) 100 (cid:7) 35% kcal from carbohydrate this carbohydrate intake is lower than the daily value and lower than the 45 to 65 percent recommendation. -3. -350 g carbohydrate (cid:6) 2 (cid:7) 700 g carbohydrate/day 700 g carbohydrate (cid:6) 4 kcal/g (cid:7) 2800 kcal from carbohydrate 2800 kcal from carbohydrate (cid:8) 6000 total kcal/day (cid:7) 0.47 0.47 (cid:6) 100 (cid:7) 47% kcal from carbohydrate highlight 4 alternatives to sugar almost everyone finds pleasure in sweet foods after all, the taste preference for sweets is inborn. -to a child, the sweeter the food, the better. -in adults, this preference is somewhat diminished, but most adults still enjoy an occa- sional sweet food or beverage. -because they want to control weight gain, blood glucose, and dental caries, many consumers turn to al- ternative sweeteners to help them limit kcalories and minimize sugar intake. -in doing so, they encounter two sets of alternative sweeteners: artificial sweeteners and sugar replacers. -artificial sweeteners . -p r o c e s e n e l e c t s h c e o h , n o i s i v i d e t t e n n u f details about each of these sweeteners. -saccharin, acesulfame-k, and sucralose are not metabolized in the body; in contrast, the body digests aspartame as a protein. -in fact, aspartame yields energy (4 kcalories per gram, as does protein), but because so little is used, its energy contribution is negligible. -some consumers have challenged the safety of using artificial sweeteners. -considering that all sub- stances are toxic at some dose, it is little surprise that large doses of artificial sweeteners (or their components or metabolic by- products) have toxic effects. -the question to ask is whether their ingestion is safe for human beings in quantities people normally use (and potentially abuse). -the food and drug administration (fda) has approved the use of several artificial sweeteners saccharin, aspartame, acesulfame potassium (acesulfame-k), sucralose, and neotame. -two others are awaiting fda approval alitame and cyclamate. -another tagatose did not need approval because it is generally recognized as a safe ingredient. -these artificial sweeteners are sometimes called nonnutritive sweeteners because they provide virtually no en- ergy. -table h4-1 and the accompanying glossary provide general saccharin saccharin, used for over 100 years in the united states, is cur- rently used by some 50 million people primarily in soft drinks, secondarily as a tabletop sweetener. -saccharin is rapidly excreted in the urine and does not accumulate in the body. -questions about saccharin s safety surfaced in 1977, when ex- periments suggested that large doses of saccharin (equivalent to g lossary acceptable daily intake (adi): the estimated amount of a sweetener that individuals can safely consume each day over the course of a lifetime without adverse effect. -acesulfame (ay-sul-fame) potassium: an artificial sweetener composed of an organic salt that has been approved for use in both the united states and canada; also known as acesulfame-k because k is the chemical symbol for potassium. -alitame (al-ih-tame): an artificial sweetener composed of two amino acids (alanine and aspartic acid); fda approval pending. -artificial sweeteners: sugar substitutes that provide negligible, if any, energy; sometimes called nonnutritive sweeteners. -132 aspartame (ah-spar-tame or ass-par-tame): an artificial sweetener composed of two amino acids (phenylalanine and aspartic acid); approved for use in both the united states and canada. -cyclamate (sigh-kla-mate): an artificial sweetener that is being considered for approval in the united states and is available in canada as a tabletop sweetener, but not as an additive. -neotame (nee-oh-tame): an artificial sweetener composed of two amino acids (phenylalanine and aspartic acid); approved for use in the united states. -nonnutritive sweeteners: sweeteners that yield no energy (or insignificant energy in the case of aspartame). -nutritive sweeteners: sweeteners sugar replacers: sugarlike that yield energy, including both sugars and sugar replacers. -saccharin (sak-ah-ren): an artificial sweetener that has been approved for use in the united states. -in canada, approval for use in foods and beverages is pending; currently available only in pharmacies and only as a tabletop sweetener, not as an additive. -stevia (stee-vee-ah): a south american shrub whose leaves are used as a sweetener; sold in the united states as a dietary supplement that provides sweetness without kcalories. -sucralose (sue-kra-lose): an artificial sweetener approved for use in the united states and canada. -compounds that can be derived from fruits or commercially produced from dextrose; also called sugar alcohols or polyols. -sugar alcohols are absorbed more slowly than other sugars and metabolized differently in the human body; they are not readily utilized by ordinary mouth bacteria. -examples are maltitol, mannitol, sorbitol, xylitol, isomalt, and lactitol. -tagatose (tag-ah-tose): a monosaccharide structurally similar to fructose that is incompletely absorbed and thus provides only 1.5 kcalories per gram; approved for use as a generally recognized as safe ingredient. -alternatives to sugar 133 table h4-1 sweeteners sweeteners relative sweetnessa energy (kcal/g) acceptable daily intake average amount to replace 1 tsp sugar approved uses approved sweeteners (trade name) saccharin (sweet n low) 450 aspartame (nutrasweet, equal, nutrataste) 200 acesulfame potassium or 200 acesulfame-k (sunette, sweet one, sweet n safe) sucralose (splenda) neotame tagatose (nutralose) 0 0 0 600 8000 18 mg/day 0.8 1.5 7.5 g/day sweeteners with approval pending alitame 2000 cyclamate 30 4e 0 0 5 mg/kg body weight 12 mg 4b 50 mg/kg body weightc 18 mg 15 mg/kg body weightd 25 mg tabletop sweeteners, wide range of foods, beverages, cosmetics, and pharmaceutical products general purpose sweetener in all foods and beverages warning to people with pku: contains phenylalanine tabletop sweeteners, puddings, gelatins, chewing gum, candies, baked goods, desserts, beverages 5 mg/kg body weight 6 mg general purpose sweetener for all foods 0.5 g 1 tsp baked goods, nonalcoholic beverages, chew- ing gum, candies, frostings, frozen desserts, gelatins, puddings, jams and jellies, syrups baked goods, beverages, cereals, chewing gum, confections, dairy products, dietary supplements, health bars, tabletop sweetener proposed uses beverages, baked goods, tabletop sweeteners, frozen desserts tabletop sweeteners, baked goods a relative sweetness is determined by comparing the approximate sweetness of a sugar substitute with the sweetness of pure sucrose, which has been defined as 1.0. chemical structure, tempera- ture, acidity, and other flavors of the foods in which the substance occurs all influence relative sweetness. -b aspartame provides 4 kcalories per gram, as does protein, but because so little is used, its energy contribution is negligible. -in powdered form, it is sometimes mixed with lactose, however, so a 1-gram packet may provide 4 kcalories. -c recommendations from the world health organization and in europe and canada limit aspar- tame intake to 40 milligrams per kilogram of body weight per day. -d recommendations from the world health organization limit acesulfame-k intake to 9 milligrams per kilogram of body weight per day. -e alitame provides 4 kcalories per gram, as does protein, but because so little is used, its energy contribution is negligible. -hundreds of cans of diet soda daily for a lifetime) increased the risk of bladder cancer in rats. -the fda proposed banning saccha- rin as a result. -public outcry in favor of saccharin was so loud, however, that congress imposed a moratorium on the ban while additional safety studies were conducted. -products containing saccharin were required to carry a warning label until 2001, when studies concluded that saccharin did not cause cancer in humans. -does saccharin cause cancer? -the largest population study to date, involving 9000 men and women, showed that overall sac- charin use did not increase the risk of cancer. -among certain small groups of the population, however, such as those who both smoked heavily and used saccharin, the risk of bladder cancer was slightly greater. -other studies involving more than 5000 people with bladder cancer showed no association between bladder can- cer and saccharin use. -in 2000, saccharin was removed from the list of suspected cancer-causing substances. -warning labels are no longer required. -common sense dictates that consuming large amounts of any substance is probably not wise, but at current, moderate intake levels, saccharin appears to be safe for most people. -it has been approved for use in more than 100 countries. -aspartame aspartame is a simple chemical compound made of compo- nents common to many foods: two amino acids (phenylalanine and aspartic acid) and a methyl group (ch3). -figure h4-1 (p. 134) shows its chemical structure. -the flavors of the compo- nents give no clue to the combined effect; one of them tastes bit- ter, and the other is tasteless, but the combination creates a product that is 200 times sweeter than sucrose. -in the digestive tract, enzymes split aspartame into its three component parts. -the body absorbs the two amino acids and uses them just as if they had come from food protein, which is made entirely of amino acids, including these two. -because this sweetener contributes phenylalanine, products containing aspartame must bear a warning label for people with the inherited disease phenylketonuria (pku). -people with pku are unable to dispose of any excess phenylalanine. -the accumulation of phenylalanine and its by-products is toxic to the developing nervous system, causing irreversible brain damage. -for this rea- son, all newborns in the united states are screened for pku. -the treatment for pku is a special diet that must strike a balance, pro- 134 highlight 4 figure h4-1 structure of aspartame figure h4-2 metabolism of aspartame h c c c c h h h h c c o h c o h c h o h c h o h aspartic acid h n c c h h n h c h c o c h aspartic acid phenylalanine amino acids h methyl group h phenylalanine o c h h methyl group hydrolyzed h h o c h h methanol oxidized h o c h formaldehyde oxidized o c o carbon dioxide viding enough phenylalanine to support normal growth and health but not enough to cause harm. -the little extra phenylala- nine from aspartame poses only a small risk, even in heavy users, but children with pku need to get all their required phenylalanine from foods instead of from an artificial sweetener. -the pku diet excludes such protein- and nutrient-rich foods as milk, meat, fish, poultry, cheese, eggs, nuts, legumes, and many bread products. -consequently, these children have difficulty obtaining the many essential nutrients such as calcium, iron, and the b vitamins found along with phenylalanine in these foods. -children with pku cannot afford to squander their limited phenylalanine al- lowance on the phenylalanine of aspartame, which contributes none of the associated vitamins or minerals essential for good health and normal growth. -during metabolism, the methyl group momentarily becomes methyl alcohol (methanol) a potentially toxic compound (see fig- ure h4-2). -this breakdown also occurs when aspartame-sweetened beverages are stored at warm temperatures over time. -the amount of methanol produced may be safe to consume, but a person may not want to, considering that the beverage has lost its sweetness. -in the body, enzymes convert methanol to formaldehyde, another toxic compound. -finally, formaldehyde is broken down to carbon dioxide. -before aspartame could be approved, the quantities of these products generated during metabolism had to be deter- mined, and they were found to fall below the threshold at which they would cause harm. -in fact, ounce for ounce, tomato juice yields six times as much methanol as a diet soda. -a recent italian study found that aspartame caused cancer in female rats and fueled the controversies surrounding aspartame s safety.1 statements from the fda and others, however, indicate that such a conclusion is not supported by the data.2 the only valid scientific concern is that for people with epilepsy, excessive intake of aspartame may decrease their threshold for seizures; this does not appear to be a problem when intakes are within recom- mended amounts.3 acesulfame-k because acesulfame potassium (acesulfame-k) passes through the body unchanged, it does not provide any energy nor does it increase the intake of potassium. -acesulfame-k is ap- proved for use in the united states, canada, and more than 60 other countries. -sucralose sucralose is unique among the artificial sweeteners in that it is made from sugar that has had three of its hydroxyl (oh) groups replaced by chlorine atoms. -the result is an exceptionally stable molecule that is much sweeter than sugar. -because the body does not recognize sucralose as a carbohydrate, it passes through the gi tract undigested and unabsorbed. -neotame like aspartame, neotame also contains the amino acids pheny- lalanine and aspartic acid and a methyl group. -unlike aspartame, however, neotame has an additional side group attached. -this simple difference makes all the difference to people with pku be- cause it blocks the digestive enzymes that normally separate phenylalanine and aspartic acid. -consequently, the amino acids are not absorbed and neotame need not carry a warning for peo- ple with pku. -tagatose the fda granted the fructose relative tagatose the status of generally recognized as safe, making it available as a low-kcalorie sweetener for a variety of foods and beverages. -this monosaccha- ride is naturally found in only a few foods, but it can be derived from lactose. -unlike fructose or lactose, however, 80 percent of tagatose remains unabsorbed until it reaches the large intestine. -there, bacteria ferment tagatose, releasing gases and short chain fatty acids that are absorbed. -as a result, tagatose provides 1.5 kcalories per gram. -at high doses, tagatose causes flatulence, rumbling, and loose stools; otherwise, no adverse side effects have been noted. -in fact, tagatose is a prebiotic that may benefit gi health. -unlike other sugars, tagatose does not promote dental caries and may carry a dental caries health claim. -alitame and cyclamate fda approval for alitame and cyclamate is still pending. -to date, no safety issues have been raised for alitame, and it has been approved for use in other countries. -in contrast, cyclamate has been battling safety issues for 50 years. -approved by the fda in 1949, cyclamate was banned in 1969 principally on the basis of one study indicating that it caused bladder cancer in rats. -the national research council has reviewed dozens of studies on cyclamate and concluded that neither cyclamate nor its metabolites cause cancer. -the council did, however, recommend further research to determine if heavy or long-term use poses risks. -although cyclamate does not initiate cancer, it may promote cancer development once it is started. -the fda currently has no policy on substances that enhance the cancer-causing activities of other substances, but it is unlikely to approve cyclamate soon, if at all. -agencies in more than 50 other countries, including canada, have approved cyclamate. -acceptable daily intake the amount of artificial sweetener considered safe for daily use is called the acceptable daily intake (adi). -the adi represents the level of consumption that, if maintained every day through- out a person s life, would still be considered safe by a wide mar- gin. -it usually reflects an amount 100 times less than the level at which no observed effects occur in animal research studies. -the adi for aspartame, for example, is 50 milligrams per kilo- gram of body weight. -that is, the fda approved aspartame based on the assumption that no one would consume more than 50 milligrams per kilogram of body weight in a day. -this maximum daily intake is indeed high: for a 150-pound adult, it adds up to 97 packets of equal or 20 cans of soft drinks sweetened only with aspartame. -the company that produces aspartame estimates that if all the sugar and saccharin in the u.s. diet were replaced with aspartame, 1 percent of the population would be consuming the fda maximum. -most people who use aspartame consume less than 5 milligrams per kilogram of body weight per day. -but a young child who drinks four glasses of aspartame-sweetened bev- erages on a hot day and has five servings of other products with aspartame that day (such as pudding, chewing gum, cereal, gel- atin, and frozen desserts) consumes the fda maximum level. -al- though this intake presents no proven hazard, it seems wise to offer children other foods so as not to exceed the limit. -table h4- 2 lists the average amounts of aspartame in some common foods. -for persons choosing to use artificial sweeteners, the american dietetic association wisely advises that they be used in modera- tion and only as part of a well-balanced nutritious diet.4 the di- alternatives to sugar 135 etary principles of moderation and variety help to reduce the pos- sible risks associated with any food. -artificial sweeteners and weight control the rate of obesity in the united states has been rising for decades. -foods and beverages sweetened with artificial sweeten- ers were among the first products developed to help people con- trol their weight. -ironically, a few studies have reported that intense sweeteners, such as aspartame, may stimulate appetite, which could lead to weight gain. -contradicting these reports, most studies find no change in feelings of hunger and no change in food intakes or body weight. -adding to the confusion, some studies report lower energy intakes and greater weight losses when people eat or drink artificially sweetened products.5 when studying the effects of artificial sweeteners on food in- take and body weight, researchers ask different questions and take different approaches. -it matters, for example, whether the people used in a study are of a healthy weight and whether they are following a weight-loss diet. -motivations for using sweeteners differ, too, and this influences a person s actions. -for example, one person might drink an artificially sweetened beverage now so as to be able to eat a high-kcalorie food later. -this person s energy intake might stay the same or increase. -a person trying to control food energy intake might drink an artificially sweetened beverage now and choose a low-kcalorie food later. -this plan would help reduce the person s total energy intake. -in designing experiments on artificial sweeteners, researchers have to distinguish between the effects of sweetness and the effects of a particular substance. -if a person is hungry shortly after eating an artificially sweetened snack, is that because the sweet taste (of all sweeteners, including sugars) stimulates appetite? -or is it because the artificial sweetener itself stimulates appetite? -research must also distinguish between the effects of food energy and the effects of the substance. -if a person is hungry shortly after eating an artificially sweetened snack, is that because less food energy was available to satisfy hunger? -or is it because the artificial sweetener itself triggers hunger? -furthermore, if appetite is stimulated and a person feels hungry, does that actually lead to increased food intake? -whether a person compensates for the energy reduction of ar- tificial sweeteners either partially or fully depends on several fac- tors. -using artificial sweeteners will not automatically lower energy intake; to control energy intake successfully, a person needs to make informed diet and activity decisions throughout the day (as chapter 9 explains). -average aspartame contents of selected table h4-2 foods food 12 oz diet soft drink 8 oz powdered drink 8 oz sugar-free fruit yogurt 4 oz gelatin dessert 1 packet sweetener aspartame (mg) 170 100 124 80 35 136 highlight 4 stevia an herbal alternative table h4-3 sugar replacers sugar alcohols relative sweetnessa energy (kcal/g) the fda has backed its approval or denial of artificial sweeteners with decades of extensive research. -such research is lacking for the herb stevia, a shrub whose leaves have long been used by the people of south america to sweeten their beverages. -in the united states, stevia is sold in health-food stores as a dietary sup- plement. -the fda has reviewed the limited research on the use of stevia as an alternative to artificial sweeteners and found concerns regarding its effect on reproduction, cancer development, and energy metabolism. -used sparingly, stevia may do little harm, but the fda could not approve its extensive and widespread use in the u.s. market. -canada, the european union, and the united nations have reached similar conclusions. -in canada, provisional guidelines have been adopted for the use of stevia as a medicinal ingredient and as a sweetening agent. -that stevia can be sold as a dietary supplement but not used as a food additive in the united states, highlights key differences in fda regulations. -food additives must prove their safety and effectiveness before receiv- ing fda approval, whereas dietary supplements are not required to submit to any testing or receive any approval. -(see highlight 10 for information on dietary supplements and highlight 18 for more on herbs.) -sugar replacers some sugar-free or reduced-kcalorie products contain sugar re- placers. -* the term sugar replacers describes the sugar alcohols familiar examples include erythritol, mannitol, sorbitol, xylitol, maltitol, isomalt, and lactitol that provide bulk and sweetness in cookies, hard candies, sugarless gums, jams, and jellies. -these products claim to be sugar-free on their labels, but in this case, sugar-free does not mean free of kcalories. -sugar replacers do provide kcalories, but fewer than their carbohydrate cousins, the sugars. -because sugar replacers yield energy, they are sometimes referred to as nutritive sweeteners. -table h4-3 includes their energy values, but a simple estimate can help consumers: divide grams by 2. sugar alcohols occur naturally in fruits and vegeta- bles; manufacturers also use sugar alcohols as a low-energy bulk ingredient in many processed foods. -* to minimize confusion, the american diabetes association prefers the term sugar replacers instead of sugar alcohols (which connotes alcohol), bulk sweeteners (which connotes fiber), or sugar substitutes (which connotes aspartame and saccharin). -erythritol 0.7 isomalt 0.5 lactitol 0.4 maltitol mannitol sorbitol xylitol 0.9 0.7 0.5 1.0 0.4 2.0 2.0 2.1 1.6 2.6 2.4 approved uses beverages, frozen dairy desserts, baked goods, chewing gum, candies candies, chewing gum, ice cream, jams and jellies, frostings, bever- ages, baked goods candies, chewing gum, frozen dairy desserts, jams and jellies, frost- ings, baked goods particularly good for candy coating bulking agent, chewing gum special dietary foods, candies, gums chewing gum, candies, pharmaceutical and oral health products a relative sweetness is determined by comparing the approximate sweetness of a sugar replacer with the sweetness of pure sucrose, which has been defined as 1.0. chemical structure, temperature, acidity, and other flavors of the foods in which the substance occurs all influence relative sweetness. -sugar alcohols evoke a low glycemic response. -the body ab- sorbs sugar alcohols slowly; consequently, they are slower to en- ter the bloodstream than other sugars. -side effects such as gas, abdominal discomfort, and diarrhea, however, make them less at- tractive than the artificial sweeteners. -for this reason, regulations require food labels to state excess consumption may have a lax- ative effect if reasonable consumption of that food could result in the daily ingestion of 50 grams of a sugar alcohol. -the real benefit of using sugar replacers is that they do not contribute to dental caries. -bacteria in the mouth cannot metab- olize sugar alcohols as rapidly as sugar. -they are therefore valu- able in chewing gums, breath mints, and other products that people keep in their mouths for a while. -figure h4-3 presents la- beling information for products using sugar alternatives. -the sugar replacers, like the artificial sweeteners, can occupy a place in the diet, and provided they are used in moderation, they will do no harm. -in fact, they can help, both by providing an al- ternative to sugar for people with diabetes and by inhibiting caries-causing bacteria. -people may find it appropriate to use all three sweeteners at times: artificial sweeteners, sugar replacers, and sugar itself. -figure h4-3 sugar alternatives on food labels alternatives to sugar 137 products containing sugar replacers may claim to not promote tooth decay if they meet fda criteria for dental plaque activity. -products containing aspartame must carry a warning for people with phenylketonuria. -ingredients: sorbitol, maltitol, gum base, mannitol, artificial and natural flavoring, acacia, softeners, titanium dioxide (color), aspartame, acesulfame potassium and candelilla wax. -phenylketonurics: contains phenylalanine. -e r o o m g i a r c this ingredient list includes both sugar alcohols and artificial sweetenters. -amount per serving % dv* 35% fewer calories than sugared gum. -nutrition facts serving size 2 pieces (3g) servings 6 calories 5 0% 0% 1% total fat 0g sodium 0mg total carb. -2g sugars 0g sugar alcohol 2g protein 0g products containing less than 0.5 g of sugar per serving can claim to be sugarless or sugar-free. -products that claim to be reduced kcalories must provide at least 25% fewer kcalories per serving than the comparison item. -*percent daily values (dv) are based on a 2,000 calorie diet. -not a significant source of other nutrients. -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 4, then to highlights nutrition on the net. -search for artificial sweeteners at the u.s. government health information site: www.healthfinder.gov references search for sweeteners at the international food information council site: www.ific.org 1. m. soffritti and coauthors, aspartame in- duces lymphomas and leukaemias in rats, european journal of oncology 10 (2005): 107- 116. -2. u.s. food and drug administration, fda statement on european aspartame study, posted may 8, 2006, www.fda.gov; m. r. weihrauch and v. diehl, artificial sweeten- ers do they bear a carcinogenic risk? -annals of oncology 15 (2004): 1460-1465. -3. s. m. jankovic, controversies with aspar- tame, medicinski pregled 56 (2003): 27-29. -4. position of the american dietetic associa- tion: use of nutritive and nonnutritive sweeteners, journal of the american dietetic association 104 (2004): 255-275. -5. s. h. f. vermunt and coauthors, effects of sugar intake on body weight: a review, obesity reviews 4 (2003): 91-99. michael paul/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow most likely, you know what you don t like about body fat, but do you appreciate how it insulates you against the cold or powers your hike around a lake? -and what about food fat? -you re right to credit fat for providing the delicious flavors animated! -figure 5.17: absorption of fat and aromas of buttered popcorn and fried chicken and to criticize it for how to: practice problems nutrition portfolio journal contributing to the weight gain and heart disease so common today. -the nutrition calculations: practice problems challenge is to strike a healthy balance of enjoying some fat, but not too much. -learning which kinds of fats are most harmful will help you make wise decisions. -the lipids: triglycerides, phospholipids, and sterols most people are surprised to learn that fat has some virtues. -only when people consume either too much or too little fat, or too much of some kinds of fat, does poor health develop. -it is true, though, that in our society of abundance, people are likely to consume too much fat. -fat refers to the class of nutrients known as lipids. -the lipid family in- cludes triglycerides (fats and oils), phospholipids, and sterols. -the triglyc- erides predominate, both in foods and in the body. -the chemist s view of fatty acids and triglycerides like carbohydrates, fatty acids and triglycerides are composed of carbon (c), hydro- gen (h), and oxygen (o). -because these lipids have many more carbons and hydro- gens in proportion to their oxygens, however, they can supply more energy per gram than carbohydrates can (chapter 7 provides details). -the many names and relationships in the lipid family can seem overwhelm- ing like meeting a friend s extended family for the first time. -to ease the introduc- tions, this chapter first presents each of the lipids from a chemist s point of view using both words and diagrams. -then the chapter follows the lipids through diges- tion and absorption and into the body to examine their roles in health and disease. -for people who think more easily in words than in chemical symbols, this preview of the upcoming chemistry may be helpful: 1. every triglyceride contains one molecule of glycerol and three fatty acids (basi- cally, chains of carbon atoms). -2. fatty acids may be 4 to 24 (even numbers of) carbons long, the 18-carbon ones being the most common in foods and especially noteworthy in nutrition. -3. fatty acids may be saturated or unsaturated. -unsaturated fatty acids may have one or more points of unsaturation. -(that is, they may be monounsaturated or polyunsaturated.) -4. of special importance in nutrition are the polyunsaturated fatty acids whose first point of unsaturation is next to the third carbon (known as omega-3 fatty acids) or next to the sixth carbon (omega-6). -5. the 18-carbon fatty acids that fit this description are linolenic acid (omega-3) and linoleic acid (omega-6). -each is the primary member of a family of longer-chain c h a p t e r 5 chapter outline the chemist s view of fatty acids and triglycerides fatty acids triglycerides degree of unsatu- ration revisited the chemist s view of phospho- lipids and sterols phospholipids sterols digestion, absorption, and transport of lipids lipid digestion lipid absorption lipid transport lipids in the body roles of triglyc- erides essential fatty acids a preview of lipid metabolism health effects and recommended intakes of lipids health effects of lipids recommended intakes of fat from guidelines to groceries highlight 5 high-fat foods friend or foe? -of the lipids in foods, 95% are fats and oils (triglycerides); of the lipids stored in the body, 99% are triglycerides. -lipids: a family of compounds that includes triglycerides, phospholipids, and sterols. -lipids are characterized by their insolubility in water. -(lipids also include the fat-soluble vita- mins, described in chapter 11.) -fats: lipids that are solid at room temperature (77 f or 25 c). -oils: lipids that are liquid at room temperature (77 f or 25 c). -139 140 chapter 5 figure 5-1 acetic acid acetic acid is a two-carbon organic acid. -methyl end h o h c c oh h acid end stearic acid, an 18-carbon saturated fatty acid fatty acids that help to regulate blood pressure, blood clotting, and other body functions important to health. -the paragraphs, definitions, and diagrams that follow present this information again in much more detail. -fatty acids a fatty acid is an organic acid a chain of carbon atoms with hydrogens at- tached that has an acid group (cooh) at one end and a methyl group (ch3) at the other end. -the organic acid shown in figure 5-1 is acetic acid, the compound that gives vinegar its sour taste. -acetic acid is the shortest such acid, with a chain only two carbon atoms long. -the length of the carbon chain most naturally occurring fatty acids contain even numbers of carbons in their chains up to 24 carbons in length. -this discus- sion begins with the 18-carbon fatty acids, which are abundant in our food supply. -stearic acid is the simplest of the 18-carbon fatty acids; the bonds between its car- bons are all alike: h h c h hh c c h h h c h h c h hh c c h h h c h h h c h c h h c h hh hh hh c c c c h h h h c h c h o c o h as you can see, stearic acid is 18 carbons long, and each atom meets the rules of chemical bonding described in figure 4-1 on p. 102. the following structure also de- picts stearic acid, but in a simpler way, with each corner on the zigzag line repre- senting a carbon atom with two attached hydrogens: stearic acid (simplified structure) h h c h o c o h as mentioned, the carbon chains of fatty acids vary in length. -the long-chain (12 to 24 carbons) fatty acids of meats, fish, and vegetable oils are most common in the diet. -smaller amounts of medium-chain (6 to 10 carbons) and short-chain (fewer than 6 carbons) fatty acids also occur, primarily in dairy products. -(tables c- 1 and c-2 in appendix c provide the names, chain lengths, and sources of fatty acids commonly found in foods.) -the degree of unsaturation stearic acid is a saturated fatty acid, (terms that describe the saturation of fatty acids are defined in the accompanying glos- sary). -a saturated fatty acid is fully loaded with hydrogen atoms and contains only single bonds between its carbon atoms. -if two hydrogens were missing from the mid- dle of the carbon chain, the remaining structure might be: h h c h hh c c h h h c h h c h hh c c h h h c h c h c h h c h hh hh hh c c c c h h h h c h c h o c o h such a compound cannot exist, however, because two of the carbons have only three bonds each, and nature requires that every carbon have four bonds. -the two carbons therefore form a double bond: an impossible chemical structure oleic acid, an 18-carbon monounsaturated fatty acid h h c h hh c c h h h c h h c h hh c c h h h c h h c h c c h h h c h hh hh c c c c h h h h h c h o c o h the lipids: triglycerides, phospholipids, and sterols 141 g lossary of fatty acid terms fatty acid: an organic compound composed of a carbon chain with hydrogens attached and an acid group (cooh) at one end and a methyl group (ch3) at the other end. -monounsaturated fatty acid (mufa): a fatty acid that lacks two hydrogen atoms and has one double bond between carbons for example, oleic acid. -a monounsaturated fat is composed of triglycerides in which most of the fatty acids are monounsaturated. -mono (cid:2) one point of unsaturation: the double bond of a fatty acid, where hydrogen atoms can easily be added to the structure. -polyunsaturated fatty acid (pufa): a fatty acid that lacks four or more hydrogen atoms and has two or more double bonds between carbons for example, linoleic acid (two double bonds) and linolenic acid (three double bonds). -a polyunsaturated fat is composed of triglycerides in which most of the fatty acids are polyunsaturated. -poly (cid:2) many saturated fatty acid: a fatty acid carrying the maximum possible number of hydrogen atoms for example, stearic acid. -a saturated fat is composed of triglycerides in which most of the fatty acids are saturated. -unsaturated fatty acid: a fatty acid that lacks hydrogen atoms and has at least one double bond between carbons (includes monounsaturated and polyunsaturated fatty acids). -an unsaturated fat is composed of triglycerides in which most of the fatty acids are unsaturated. -the same structure drawn more simply looks like this: h h c h o c o h the double bond is a point of unsaturation. -hence, a fatty acid like this with two hydrogens missing and a double bond is an unsaturated fatty acid. -this one is the 18-carbon monounsaturated fatty acid oleic acid, which is abundant in olive oil and canola oil. -a polyunsaturated fatty acid has two or more carbon-to-carbon double bonds. -linoleic acid, the 18-carbon fatty acid common in vegetable oils, lacks four hydrogens and has two double bonds: oleic acid (simplified structure) remember that each corner on the zigzag line represents a carbon atom with two attached hydrogens. -in addition, although drawn straight here, the actual shape kinks at the double bonds (as shown in the left side of figure 5-8). -hh hh h c c c c h h h h h c h h c h c c c c h h hh h c h hh hh hh c c c c h h h h c h c h o c o h linoleic acid, an 18-carbon polyunsaturated fatty acid drawn more simply, linoleic acid looks like this (though the actual shape would kink at the double bonds): h h c h o c o h linoleic acid (simplified structure) a fourth 18-carbon fatty acid is linolenic acid, which has three double bonds. -table 5-1 presents the 18-carbon fatty acids. -the location of double bonds fatty acids differ not only in the length of their chains and their degree of saturation, but also in the locations of their double bonds. -chemists identify polyunsaturated fatty acids by the position of the double bond nearest the methyl (ch3) end of the carbon chain, which is described by an omega number. -a polyunsaturated fatty acid with its first double bond three carbons away table 5-1 18-carbon fatty acids chemists use a shorthand notation to describe fatty acids. -the first number indicates the number of carbon atoms; the second, the number of the double bonds. -for example, the notation for stearic acid is 18:0. name stearic acid oleic acid linoleic acid linolenic acid number of number of carbon atoms double bonds saturation common food sources 18 18 18 18 0 1 2 3 saturated most animal fats monounsaturated olive, canola oils polyunsaturated polyunsaturated sunflower, safflower, corn, and soybean oils soybean and canola oils, flaxseed, walnuts linoleic (lin-oh-lay-ick) acid: an essential fatty acid with 18 carbons and two double bonds. -linolenic (lin-oh-len-ick) acid: an essential fatty acid with 18 carbons and three double bonds. -omega: the last letter of the greek alphabet ( ), used by chemists to refer to the position of the first double bond from the methyl (ch3) end of a fatty acid. -142 chapter 5 figure 5-2 omega-3 and omega-6 fatty acids compared the omega number indicates the position of the first double bond in a fatty acid, counting from the methyl (ch3) end. -thus an omega-3 fatty acid s first double bond occurs three carbons from the methyl end, and an omega-6 fatty acid s first double bond occurs six carbons from the methyl end. -the members of an omega family may have different lengths and different numbers of double bonds, but the first double bond occurs at the same point in all of them. -these structures are drawn linearly here to ease counting carbons and locating double bonds, but their shapes actually bend at the double bonds, as shown in figure 5-8 (p. 145). -linolenic acid, an omega-3 fatty acid omega carbon h h c h 3 methyl end linoleic acid, an omega-6 fatty acid omega carbon 6 h h c h methyl end o c o h acid end o c o h acid end figure 5-3 glycerol when glycerol is free, an oh group is attached to each carbon. -when glycerol is part of a triglyceride, each carbon is attached to a fatty acid by a carbon-oxygen bond. -h h h h c o h c o h c o h h the food industry often refers to these satu- rated vegetable oils as the tropical oils. -omega-3 fatty acid: a polyunsaturated fatty acid in which the first double bond is three carbons away from the methyl (ch3) end of the carbon chain. -omega-6 fatty acid: a polyunsaturated fatty acid in which the first double bond is six carbons from the methyl (ch3) end of the carbon chain. -triglycerides (try-gliss-er-rides): the chief form of fat in the diet and the major storage form of fat in the body; composed of a molecule of glycerol with three fatty acids attached; also called triacylglycerols (try- ay-seel-gliss-er-ols). -* tri = three glyceride = of glycerol acyl = a carbon chain glycerol (gliss-er-ol): an alcohol composed of a three-carbon chain, which can serve as the backbone for a triglyceride. -ol = alcohol from the methyl end is an omega-3 fatty acid. -similarly, an omega-6 fatty acid is a polyunsaturated fatty acid with its first double bond six carbons away from the methyl end. -figure 5-2 compares two 18-carbon fatty acids linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid). -triglycerides few fatty acids occur free in foods or in the body. -most often, they are incorporated into triglycerides lipids composed of three fatty acids attached to a glycerol. -(figure 5-3 presents a glycerol molecule.) -to make a triglyceride, a series of conden- sation reactions combine a hydrogen atom (h) from the glycerol and a hydroxyl (oh) group from a fatty acid, forming a molecule of water (h2o) and leaving a bond between the other two molecules (see figure 5-4). -most triglycerides contain a mix- ture of more than one type of fatty acid (see figure 5-5). -degree of unsaturation revisited the chemistry of a fatty acid whether it is short or long, saturated or unsatu- rated, with its first double bond here or there influences the characteristics of foods and the health of the body. -a section later in this chapter explains how these features affect health; this section describes how the degree of unsaturation influ- ences the fats and oils in foods. -firmness the degree of unsaturation influences the firmness of fats at room tem- perature. -generally speaking, the polyunsaturated vegetable oils are liquid at room temperature, and the more saturated animal fats are solid. -not all vegetable oils are polyunsaturated, however. -cocoa butter, palm oil, palm kernel oil, and coconut oil are saturated even though they are of vegetable origin; they are firmer than most vegetable oils because of their saturation, but softer than most animal fats because of their shorter carbon chains (8 to 14 carbons long). -generally, the shorter the car- * research scientists commonly use the term triacylglycerols; this book continues to use the more famil- iar term triglycerides, as do many other health and nutrition books and journals. -the lipids: triglycerides, phospholipids, and sterols 143 figure 5-4 condensation of glycerol and fatty acids to form a triglyceride to make a triglyceride, three fatty acids attach to glycerol in condensation reactions. -h h c o h h o h c o h h o h c o h h o h o c o c o c h c h h c h h c h h h h o c o c o c h h c o h c o h c o h h c h h c h h c h h + h2o h + h2o h + h2o glycerol + 3 fatty acids triglyceride + 3 water molecules an h atom from glycerol and an oh group from a fatty acid combine to create water, leaving the o on the glycerol and the c at the acid end of each fatty acid to form a bond. -three fatty acids attached to a glycerol form a triglyceride and yield water. -in this example, all three fatty acids are stearic acid, but most often triglycerides contain mixtures of fatty acids (as shown in figure 5-5). -bon chain, the softer the fat is at room temperature. -fatty acid compositions of se- lected fats and oils are shown in figure 5-6 (p. 144), and appendix h provides the fat and fatty acid contents of many other foods. -stability saturation also influences stability. -all fats become spoiled when ex- posed to oxygen. -polyunsaturated fats spoil most readily because their double bonds are unstable; monounsaturated fats are slightly less susceptible. -saturated fats are most resistant to oxidation and thus least likely to become rancid. -the oxidation of fats produces a variety of compounds that smell and taste rancid; other types of spoilage can occur due to microbial growth. -manufacturers can protect fat-containing products against rancidity in three ways none of them perfect. -first, products may be sealed in air-tight, nonmetallic containers, protected from light, and refrigerated an expensive and inconvenient storage system. -second, manufacturers may add antioxidants to compete for the oxygen and thus protect the oil (examples are the additives bha and bht and vita- min e). -* the advantages and disadvantages of antioxidants in food processing are presented in chapter 19. third, manufacturers may saturate some or all of the points of unsaturation by adding hydrogen molecules a process known as hydrogenation. -hydrogenation hydrogenation offers two advantages. -first, it protects against oxidation (thereby prolonging shelf life) by making polyunsaturated fats more sat- urated (see figure 5-7, p. 144). -second, it alters the texture of foods by making liquid vegetable oils more solid (as in margarine and shortening). -hydrogenated fats make margarine spreadable, pie crusts flaky, and puddings creamy. -trans-fatty acids figure 5-7 illustrates the total hydrogenation of a polyunsatu- rated fatty acid to a saturated fatty acid, which rarely occurs during food processing. -most often, a fat is partially hydrogenated, and some of the double bonds that re- main after processing change from cis to trans. -in nature, most double bonds are cis meaning that the hydrogens next to the double bonds are on the same side of the carbon chain. -only a few fatty acids (notably a small percentage of those found in milk and meat products) are trans-fatty acids meaning that the hydrogens next to the double bonds are on opposite sides of the carbon chain (see figure 5-8, p. -145). -** these arrangements result in different configurations for the fatty acids, and this difference affects function: in the body, trans-fatty acids that derive from hydrogenation behave more like saturated fats than like unsaturated fats. -the re- lationship between trans-fatty acids and heart disease has been the subject of much * bha is butylated hydroxyanisole; bht is butylated hydroxytoluene. -** for example, most dairy products contain less than 0.5 grams trans fat per serving. -figure 5-5 a mixed triglyceride o c o c o c h h c o h c o h c o h h hc h h hc h h hc h this mixed triglyceride includes a saturated fatty acid, a monounsaturated fatty acid, and a polyunsaturated fatty acid, respectively. -oxidation (oks-ee-day-shun): the process of a substance combining with oxygen; oxidation reactions involve the loss of electrons. -antioxidants: as a food additive, preservatives that delay or prevent rancidity of fats in foods and other damage to food caused by oxygen. -hydrogenation (high-dro-jen-ay-shun or high-droj-eh-nay-shun): a chemical process by which hydrogens are added to monounsaturated or polyunsaturated fatty acids to reduce the number of double bonds, making the fats more saturated (solid) and more resistant to oxidation (protecting against rancidity). -hydrogenation produces trans-fatty acids. -trans-fatty acids: fatty acids with hydrogens on opposite sides of the double bond. -144 chapter 5 . -c n i s o i d u t s a r a l o p at room temperature, saturated fats (such as those commonly found in butter and other animal fats) are solid, whereas unsaturated fats (such as those found in vegetable oils) are usually liquid. -conjugated linoleic acid: a collective term for several fatty acids that have the same chemical formula as linoleic acid (18 carbons, two double bonds) but with different configurations. -figure 5-6 comparison of dietary fats most fats are a mixture of saturated, monounsaturated, and polyunsaturated fatty acids. -key: saturated monounsaturated polyunsaturated, omega-6 polyunsaturated, omega-3 animal fats and the tropical oils of coconut and palm are mostly saturated fatty acids. -coconut oil butter beef tallow palm oil lard some vegetable oils, such as olive and canola, are rich in monounsaturated fatty acids. -olive oil canola oil peanut oil many vegetable oils are rich in polyunsaturated fatty acids. -safflower oil flaxseed oil walnut oil sunflower oil corn oil recent research, as a later section describes. -in contrast, naturally occurring fatty acids, such as conjugated linoleic acid, that have a trans configuration may have health benefits.1 in summary the predominant lipids both in foods and in the body are triglycerides: glyc- erol backbones with three fatty acids attached. -fatty acids vary in the length of their carbon chains, their degrees of unsaturation, and the location of their double bond(s). -those that are fully loaded with hydrogens are saturated; those that are missing hydrogens and therefore have double bonds are unsat- urated (monounsaturated or polyunsaturated). -the vast majority of triglyc- erides contain more than one type of fatty acid. -fatty acid saturation affects fats physical characteristics and storage properties. -hydrogenation, which makes polyunsaturated fats more saturated, gives rise to trans-fatty acids, al- tered fatty acids that may have health effects similar to those of saturated fatty acids. -figure 5-7 hydrogenation double bonds carry a slightly negative charge and readily accept positively charged hydrogen atoms, creating a saturated fatty acid. -most often, fat is partially hydro- genated, creating a trans-fatty acid (shown in figure 5-8). -h h c h o c o h h+ h+ h+ h+ h h c h o c o h polyunsaturated fatty acid hydrogenated (saturated) fatty acid figure 5-8 cis- and trans-fatty acids compared this example shows the cis configuration for an 18-carbon monounsaturated fatty acid (oleic acid) and its corresponding trans configuration (elaidic acid). -the lipids: triglycerides, phospholipids, and sterols 145 h h o h c o h h c h h h c h h h o c o h cis-fatty acid trans-fatty acid a cis-fatty acid has its hydrogens on the same side of the double bond; cis molecules fold back into a u-like formation. -most naturally occuring unsaturated fatty acids in foods are cis. -a trans-fatty acid has its hydrogens on the opposite sides of the double bond; trans molecules are more linear. -the trans form typically occurs in partially hydrogenated foods when hydrogen atoms shift around some double bonds and change the configuration from cis to trans. -the chemist s view of phospholipids and sterols the preceding pages have been devoted to one of the three classes of lipids, the triglycerides, and their component parts, the fatty acids. -the other two classes of lipids, the phospholipids and sterols, make up only 5 percent of the lipids in the diet. -phospholipids the best-known phospholipid is lecithin. -a diagram of a lecithin molecule is shown in figure 5-9 (p. 146). -notice that lecithin has a backbone of glycerol with two of its three attachment sites occupied by fatty acids like those in triglycerides. -the third site is occupied by a phosphate group and a molecule of choline. -the fatty acids make phospholipids soluble in fat; the phosphate group allows them to dissolve in water. -such versatility enables the food industry to use phospholipids as emulsifiers to mix fats with water in such products as mayonnaise and candy bars. -phospholipids in foods in addition to the phospholipids used by the food indus- try as emulsifiers, phospholipids are also found naturally in foods. -the richest food sources of lecithin are eggs, liver, soybeans, wheat germ, and peanuts. -roles of phospholipids the lecithins and other phospholipids are important constituents of cell membranes (see figure 5-10, p. 146). -because phospholipids are soluble in both water and fat, they can help lipids move back and forth across the cell membranes into the watery fluids on both sides. -thus they enable fat-soluble substances, including vitamins and hormones, to pass easily in and out of cells. -the phospholipids also act as emulsifiers in the body, helping to keep fats suspended in the blood and body fluids. -lecithin periodically receives attention in the popular press. -its advocates claim that it is a major constituent of cell membranes (true), that cell membranes are es- sential to the integrity of cells (true), and that consumers must therefore take lecithin supplements (false). -the liver makes from scratch all the lecithin a person needs. -as for lecithin taken as a supplement, the digestive enzyme lecithinase in the intes- tine hydrolyzes most of it before it passes into the body, so little lecithin reaches the tissues intact. -in other words, lecithin is not an essential nutrient; it is just another reminder: emulsifiers are substances with both water-soluble and fat-soluble portions that promote the mixing of oils and fats in watery solutions. -reminder: the word ending -ase denotes an enzyme. -hence, lecithinase is an enzyme that works on lecithin. -phospholipid (fos-foe-lip-id): a compound similar to a triglyceride but having a phosphate group (a phosphorus-containing salt) and choline (or another nitrogen- containing compound) in place of one of the fatty acids. -lecithin (less-uh-thin): one of the phospholipids. -both nature and the food industry use lecithin as an emulsifier to combine water-soluble and fat-soluble ingredients that do not ordinarily mix, such as water and oil. -choline (koh-leen): a nitrogen-containing compound found in foods and made in the body from the amino acid methionine. -choline is part of the phospholipid lecithin and the neurotransmitter acetylcholine. -146 chapter 5 figure 5-9 lecithin lecithin is one of the phospholipids. -notice that a molecule of lecithin is similar to a triglyceride but contains only two fatty acids. -the third position is occupied by a phos- phate group and a molecule of choline. -other phospholipids have different fatty acids at the upper two positions and different groups attached to phosphate. -oil h h c o h c o o c o c from 2 fatty acids h hc h h hc h h c o h o p o h o c h h c h ch3 + n ch3 ch3 from glycerol from phosphate the plus charge on the n is balanced by a negative ion usually chloride. -from choline water o i g g u r r a f w e h t t a m without help from emulsifiers, fats and water don t mix. -figure 5-10 membrane phospholipids of a cell a cell membrane is made of phospholipids assembled into an orderly formation called a bilayer. -the fatty acid tails orient themselves away from the watery fluid inside and outside of the cell. -the glycerol and phosphate heads are attracted to the watery fluid. -outside cell watery fluid glycerol heads fatty acid tails inside cell watery fluid the chemical structure is the same, but cho- lesterol that is made in the body is called en- dogenous (en-dogde-eh-nus), whereas cholesterol from outside the body (from foods) is called exogenous (eks-odge-eh- nus). -endo = within gen = arising exo = outside (the body) sterols (stare-ols or steer-ols): compounds containing a four ring carbon structure with any of a variety of side chains attached. -cholesterol (koh-less-ter-ol): one of the sterols containing a four ring carbon structure with a carbon side chain. -lipid. -like other lipids, lecithin contributes 9 kcalories per gram an unexpected bonus many people taking lecithin supplements fail to realize. -furthermore, large doses of lecithin may cause gi distress, sweating, and loss of appetite. -perhaps these symptoms can be considered beneficial if they serve to warn people to stop self-dosing with lecithin. -in summary phospholipids, including lecithin, have a unique chemical structure that al- lows them to be soluble in both water and fat. -in the body, phospholipids are part of cell membranes; the food industry uses phospholipids as emulsifiers to mix fats with water. -sterols in addition to triglycerides and phospholipids, the lipids include the sterols, com- pounds with a multiple-ring structure. -* the most famous sterol is cholesterol; fig- ure 5-11 (p. 147) shows its chemical structure. -sterols in foods foods derived from both plants and animals contain sterols, but only those from animals contain significant amounts of cholesterol meats, eggs, fish, poultry, and dairy products. -some people, confused about the distinction be- tween dietary and blood cholesterol, have asked which foods contain the good cholesterol. -good cholesterol is not a type of cholesterol found in foods, but it refers to the way the body transports cholesterol in the blood, as explained later (p. 152). -sterols other than cholesterol are naturally found in all plants. -being struc- turally similar to cholesterol, these plant sterols interfere with cholesterol absorp- tion, thus lowering blood cholesterol levels.2 food manufacturers have fortified foods such as margarine with plant sterols, creating a functional food that helps to reduce blood cholesterol. -* the four-ring core structure identifies a steroid; sterols are alcohol derivatives with a steroid ring structure. -the lipids: triglycerides, phospholipids, and sterols 147 roles of sterols many vitally important body compounds are sterols. -among them are bile acids, the sex hormones (such as testosterone), the adrenal hormones (such as cortisol), and vitamin d, as well as cholesterol itself. -cholesterol in the body can serve as the starting material for the synthesis of these compounds or as a structural component of cell membranes; more than 90 percent of all the body s cho- lesterol resides in the cells. -despite popular impressions to the contrary, cholesterol is not a villain lurking in some evil foods it is a compound the body makes and uses. -right now, as you read, your liver is manufacturing cholesterol from fragments of carbohydrate, protein, and fat. -in fact, the liver makes about 800 to 1500 mil- ligrams of cholesterol per day, thus contributing much more to the body s total than does the diet. -cholesterol s harmful effects in the body occur when it forms deposits in the ar- tery walls. -these deposits lead to atherosclerosis, a disease that causes heart at- tacks and strokes. -(chapter 18 provides many more details.) -in summary sterols have a multiple-ring structure that differs from the structure of other lipids. -in the body, sterols include cholesterol, bile, vitamin d, and some hor- mones. -animal-derived foods contain cholesterol. -to summarize, the mem- bers of the lipid family include: triglycerides (fats and oils), which are made of: glycerol (1 per triglyceride) and fatty acids (3 per triglyceride); depending on the number of double bonds, fatty acids may be: saturated (no double bonds) monounsaturated (one double bond) polyunsaturated (more than one double bond); depending on the loca- tion of the double bonds, polyunsaturated fatty acids may be: omega-3 (first double bond 3 carbons away from methyl end) omega-6 (first double bond 6 carbons away from methyl end) phospholipids (such as lecithin) sterols (such as cholesterol) digestion, absorption, and transport of lipids each day, the gi tract receives, on average from the food we eat, 50 to 100 grams of triglycerides, 4 to 8 grams of phospholipids, and 200 to 350 milligrams of choles- terol. -the body faces a challenge in digesting and absorbing these lipids: getting at them. -fats are hydrophobic that is, they tend to separate from the watery fluids of the gi tract whereas the enzymes for digesting fats are hydrophilic. -the chal- lenge is keeping the fats mixed in the watery fluids of the gi tract. -lipid digestion the goal of fat digestion is to dismantle triglycerides into small molecules that the body can absorb and use namely, monoglycerides, fatty acids, and glycerol. -fig- ure 5-12 (p. 148) traces the digestion of triglycerides through the gi tract, and the fol- lowing paragraphs provide the details. -in the mouth fat digestion starts off slowly in the mouth, with some hard fats be- ginning to melt when they reach body temperature. -a salivary gland at the base of the tongue releases an enzyme (lingual lipase) that plays a minor role in fat figure 5-11 cholesterol the fat-soluble vitamin d is synthesized from cholesterol; notice the many structural similar- ities. -the only difference is that cholesterol has a closed ring (highlighted in red), whereas vitamin d s is open, accounting for its vitamin activity. -notice, too, how different cholesterol is from the triglycerides and phospholipids. -ch3 ch3 ch3 ch3 ho h3c ch3 ch3 ch2 cholesterol h3c ch3 vitamin d3 compounds made from cholestrol: bile acids steroid hormones (testosterone, andro- gens, estrogens, progesterones, cortisol, cortisone, and aldosterone) vitamin d for perspective, the daily value for cholesterol is 300 mg/day. -reminder: an enzyme that hydrolyzes lipids is called a lipase; lingual refers to the tongue. -atherosclerosis (ath-er-oh-scler-oh-sis): a type of artery disease characterized by placques (accumulations of lipid-containing material) on the inner walls of the arteries (see chapter 18). -hydrophobic (high-dro-foe-bick): a term referring to water-fearing, or non-water- soluble, substances; also known as lipophilic (fat loving). -hydro = water phobia = fear lipo = lipid phile = love hydrophilic (high-dro-fil-ick): a term referring to water-loving, or water-soluble, substances. -monoglycerides: molecules of glycerol with one fatty acid attached. -a molecule of glycerol with two fatty acids attached is a diglyceride. -mono = one di = two 148 chapter 5 figure 5-12 fat digestion in the gi tract fat mouth and salivary glands some hard fats begin to melt as they reach body temperature. -the sublingual salivary gland in the base of the tongue secretes lingual lipase. -stomach the acid-stable lingual lipase initiates lipid digestion by hydrolyzing one bond of triglycerides to produce diglycerides and fatty acids. -the degree of hydrolysis by lingual lipase is slight for most fats but may be appreciable for milk fats. -the stomach s churning action mixes fat with water and acid. -a gastric lipase accesses and hydrolyzes (only a very small amount of) fat. -salivary glands mouth tongue sublingual salivary gland stomach (liver) pancreatic duct gallbladder pancreas common bile duct small intestine bile flows in from the gallbladder (via the common bile duct): fat bile emulsified fat pancreatic lipase flows in from the pancreas (via the pancreatic duct): pancreatic (and intestinal) lipase emulsified fat (triglycerides) monoglycerides, glycerol, fatty acids (absorbed) large intestine some fat and cholesterol, trapped in fiber, exit in feces. -small intestine large intestine digestion in adults and an active role in infants. -in infants, this enzyme efficiently digests the short- and medium-chain fatty acids found in milk. -in the stomach in a quiet stomach, fat would float as a layer above the other components of swallowed food. -but the strong muscle contractions of the stomach propel the stomach contents toward the pyloric sphincter. -some chyme passes the lipids: triglycerides, phospholipids, and sterols 149 through the pyloric sphincter periodically, but the remaining partially digested food is propelled back into the body of the stomach. -this churning grinds the solid pieces to finer particles, mixes the chyme, and disperses the fat into smaller droplets. -these actions help to expose the fat for attack by the gastric lipase enzyme an enzyme that performs best in the acidic environment of the stomach. -still, little fat digestion takes place in the stomach; most of the action occurs in the small intestine. -in the small intestine when fat enters the small intestine, it triggers the re- lease of the hormone cholecystokinin (cck), which signals the gallbladder to release its stores of bile. -(remember that the liver makes bile, and the gallblad- der stores it until it is needed.) -among bile s many ingredients are bile acids, which are made in the liver from cholesterol and have a similar structure. -in addition, they often pair up with an amino acid (a building block of protein). -the amino acid end is attracted to water, and the sterol end is attracted to fat (see figure 5-13, p. 150). -this structure improves bile s ability to act as an emul- sifier, drawing fat molecules into the surrounding watery fluids. -there, the fats are fully digested as they encounter lipase enzymes from the pancreas and small intestine. -the process of emulsification is diagrammed in figure 5-14 (p. 150). -most of the hydrolysis of triglycerides occurs in the small intestine. -the major fat-digesting enzymes are pancreatic lipases; some intestinal lipases are also active. -these enzymes remove one, then the other, of each triglyceride s outer fatty acids, leaving a monoglyceride. -occasionally, enzymes remove all three fatty acids, leav- ing a free molecule of glycerol. -hydrolysis of a triglyceride is shown in figure 5-15 (p. 151). -phospholipids are digested similarly that is, their fatty acids are removed by hydrolysis. -the two fatty acids and the remaining phospholipid fragment are then absorbed. -most sterols can be absorbed as is; if any fatty acids are attached, they are first hydrolyzed off. -bile s routes after bile enters the small intestine and emulsifies fat, it has two pos- sible destinations, illustrated in figure 5-16 (p. 151). -most of the bile is reabsorbed from the intestine and recycled. -the other possibility is that some of the bile can be trapped by dietary fibers in the large intestine and carried out of the body with the feces. -because cholesterol is needed to make bile, the excretion of bile effectively re- duces blood cholesterol. -as chapter 4 explains, the dietary fibers most effective at lowering blood cholesterol this way are the soluble fibers commonly found in fruits, whole grains, and legumes. -lipid absorption figure 5-17 (p. 152) illustrates the absorption of lipids. -small molecules of digested triglycerides (glycerol and short- and medium-chain fatty acids) can diffuse easily into the intestinal cells; they are absorbed directly into the bloodstream. -larger molecules (the monoglycerides and long-chain fatty acids) merge into spherical complexes, known as micelles. -micelles are emulsified fat droplets formed by mol- ecules of bile surrounding monoglycerides and fatty acids. -this configuration per- mits solubility in the watery digestive fluids and transportation to the intestinal cells. -upon arrival, the lipid contents of the micelles diffuse into the intestinal cells. -once inside, the monoglycerides and long-chain fatty acids are reassembled into new triglycerides. -within the intestinal cells, the newly made triglycerides and other lipids (choles- terol and phospholipids) are packed with protein into transport vehicles known as chylomicrons. -the intestinal cells then release the chylomicrons into the lym- phatic system. -the chylomicrons glide through the lymph until they reach a point of entry into the bloodstream at the thoracic duct near the heart. -(recall from chapter 3 that nutrients from the gi tract that enter the lymph system bypass the liver at first.) -the blood carries these lipids to the rest of the body for immediate use in addition to bile acids and bile salts, bile contains cholesterol, phospholipids (especially lecithin), antibodies, water, elec- trolytes, and bilirubin and biliverdin (pigments resulting from the breakdown of heme). -micelles (my-cells): tiny spherical complexes of emulsified fat that arise during digestion; most contain bile salts and the products of lipid digestion, including fatty acids, monoglycerides, and cholesterol. -chylomicrons (kye-lo-my-cronz): the class of lipoproteins that transport lipids from the intestinal cells to the rest of the body. -150 chapter 5 figure 5-13 a bile acid this is one of several bile acids the liver makes from cholesterol. -it is then bound to an amino acid to improve its ability to form micelles, spherical complexes of emulsified fat. -most bile acids occur as bile salts, usually in association with sodium, but sometimes with potassium or calcium. -bile acid made from cholesterol (hydrophobic) ch3 bound to an amino acid from protein (hydrophilic) ho ch ch2 ch2 c nh ch2 cooh o ho h oh or storage. -a look at these lipids in the body reveals the kinds of fat the diet has been delivering.3 the fat stores and muscle cells of people who eat a diet rich in un- saturated fats, for example, contain more unsaturated fats than those of people who select a diet high in saturated fats. -in summary the body makes special arrangements to digest and absorb lipids. -it provides the emulsifier bile to make them accessible to the fat-digesting lipases that dis- mantle triglycerides, mostly to monoglycerides and fatty acids, for absorption by the intestinal cells. -the intestinal cells assemble freshly absorbed lipids into chylomicrons, lipid packages with protein escorts, for transport so that cells all over the body may select needed lipids from them. -lipoproteins (lip-oh-pro-teenz): clusters of lipids associated with proteins that serve as transport vehicles for lipids in the lymph and blood. -lipid transport the chylomicrons are only one of several clusters of lipids and proteins that are used as transport vehicles for fats. -as a group, these vehicles are known as lipoproteins, figure 5-14 emulsification of fat by bile like bile, detergents are emulsifiers and work the same way, which is why they are effective in removing grease spots from clothes. -molecule by molecule, the grease is dissolved out of the spot and suspended in the water, where it can be rinsed away. -fat watery gi juices enzymes fat bile emulsified fat enzyme emulsified fat emulsified fat in the stomach, the fat and watery gi juices tend to separate. -the enzymes in the gi juices can t get at the fat. -when fat enters the small intestine, the gallbladder secretes bile. -bile has an affinity for both fat and water, so it can bring the fat into the water. -bile s emulsifying action converts large fat globules into small droplets that repel each other. -after emulsification, more fat is exposed to the enzymes, making fat digestion more efficient. -figure 5-15 digestion (hydrolysis) of a triglyceride bonds break the lipids: triglycerides, phospholipids, and sterols 151 o c o c o c h o h h h c o h c o h c o h h o h bonds break triglyceride h hc h h hc h h hc h h h c o h h o h c o o c h c o h h o h o c o c h hc h h hc h h hc h the triglyceride and two molecules of water are split. -the h and oh from water complete the structures of two fatty acids and leave a monoglyceride. -monoglyceride + 2 fatty acids these products may pass into the intestinal cells, but sometimes the monoglyceride is split with another molecule of water to give a third fatty acid and glycerol. -fatty acids, monoglycerides, and glycerol are absorbed into intestinal cells. -and they solve the body s problem of transporting fat through the watery blood- stream. -the body makes four main types of lipoproteins, distinguished by their size and density. -* each type contains different kinds and amounts of lipids and proteins. -figure 5-18 (p. 153) shows the relative compositions and sizes of the lipoproteins. -chylomicrons the chylomicrons are the largest and least dense of the lipopro- teins. -they transport diet-derived lipids (mostly triglycerides) from the intestine (via the lymph system) to the rest of the body. -cells all over the body remove triglycerides from the chylomicrons as they pass by, so the chylomicrons get smaller and smaller. -within 14 hours after absorption, most of the triglycerides have been depleted, and only a few remnants of protein, cholesterol, and phospholipid remain. -special pro- tein receptors on the membranes of the liver cells recognize and remove these chy- lomicron remnants from the blood. -after collecting the remnants, the liver cells first dismantle them and then either use or recycle the pieces. -vldl (very-low-density lipoproteins) meanwhile, in the liver the most ac- tive site of lipid synthesis cells are synthesizing other lipids. -the liver cells use fatty acids arriving in the blood to make cholesterol, other fatty acids, and other com- pounds. -at the same time, the liver cells may be making lipids from carbohydrates, proteins, or alcohol. -ultimately, the lipids made in the liver and those collected from chylomicron remnants are packaged with proteins as vldl (very-low-density lipoprotein) and shipped to other parts of the body. -as the vldl travel through the body, cells remove triglycerides, causing the vldl to shrink. -as a vldl loses triglycerides, the proportion of lipids shifts, and the lipoprotein density increases. -the remaining cholesterol-rich lipoprotein eventually becomes an ldl (low-density lipoprotein). -** this transformation explains why ldl contain few triglycerides but are loaded with cholesterol. -* chemists can identify the various lipoproteins by their density. -they place a blood sample below a thick fluid in a test tube and spin the tube in a centrifuge. -the most buoyant particles (highest in lipids) rise to the top and have the lowest density; the densest particles (highest in proteins) remain at the bottom and have the highest density. -others distribute themselves in between. -** before becoming ldl, the vldl are first transformed into intermediate-density lipoproteins (idl), sometimes called vldl remnants. -some idl may be picked up by the liver and rapidly broken down; those idl that remain in circulation continue to deliver triglycerides to the cells and eventually become ldl. -researchers debate whether idl are simply transitional particles or a separate class of lipoproteins; normally, idl do not accumulate in the blood. -measures of blood lipids include idl with ldl. -figure 5-16 enterohepatic circulation most of the bile released into the small intestine is reabsorbed and sent back to the liver to be reused. -this cycle is called the enterohepatic circulation of bile. -some bile is excreted. -enteron (cid:2) intestine hepat (cid:2) liver in the gallbladder, bile is stored. -in the liver, bile is made from cholesterol. -in the small intestine, bile emulsifies fats. -bile reabsorb e d into the bloo d in the colon, bile that has been trapped by soluble fibers is lost in feces. -the more lipids, the lower the density; the more proteins, the higher the density. -vldl (very-low-density lipoprotein): the type of lipoprotein made primarily by liver cells to transport lipids to various tissues in the body; composed primarily of triglycerides. -ldl (low-density lipoprotein): the type of lipoprotein derived from very-low-density lipoproteins (vldl) as vldl triglycerides are removed and broken down; composed primarily of cholesterol. -152 chapter 5 figure 5-17 animated! -absorption of fat the end products of fat digestion are mostly monoglycerides, some fatty acids, and very little glycerol. -their absorption differs depending on their size. -(in reality, molecules of fatty acid are too small to see without a powerful microscope, whereas villi are visible to the naked eye.) -to test your understanding of these concepts, log on to www.thomsonedu.com/login (including ldl (low-density lipoproteins) the ldl circulate throughout the body, making their contents avail- able to the cells of all tissues muscles the heart muscle), fat stores, the mammary glands, and others. -the cells take triglycerides, cholesterol, and phospholipids to build new mem- branes, make hormones or other compounds, or store for later use. -special ldl receptors on the liver cells play a crucial role in the con- trol of blood cholesterol concen- trations by removing ldl from circulation. -hdl (high-density lipopro- teins) fat cells may release glyc- erol, fatty acids, cholesterol, and phospholipids to the blood. -the liver makes hdl (high-density lipoprotein) to carry cholesterol from the cells back to the liver for recycling or disposal. -monoglyceride micelle protein triglyceride chylomicron long- chain fatty acids large lipids such as monoglycerides and long-chain fatty acids combine with bile, forming micelles that are sufficiently water soluble to penetrate the watery solution that bathes the absorptive cells. -there the lipid contents of the micelles diffuse into the cells. -via lymph to blood health implications the distinc- tion between ldl and hdl has im- plications for the health of the heart and blood vessels. -the blood choles- terol linked to heart disease is ldl cholesterol. -hdl also carry choles- terol, but elevated hdl represent cholesterol returning from the rest of the body to the liver for breakdown and excretion. -high ldl cholesterol is associated with a high risk of heart attack, whereas high hdl cholesterol seems to have a protective effect. -this is why some people refer to ldl as bad, and hdl as good, cholesterol. -keep in mind that the cholesterol itself is the same, and that the differences between ldl and hdl reflect the proportions and types of lipids and proteins within them not the type of cholesterol. -the margin lists factors that influence ldl and hdl, and chapter 18 provides many more details. -not too surprisingly, numerous genes influence how the body handles the up- take, synthesis, transport, and degradation of the lipoproteins. -much current re- search is focused on how nutrient-gene interactions may direct the progression of heart disease. -in summary the liver assembles lipids and proteins into lipoproteins for transport around the body. -all four types of lipoproteins carry all classes of lipids (triglycerides, phospholipids, and cholesterol), but the chylomicrons are the largest and the highest in triglycerides; vldl are smaller and are about half triglycerides; ldl are smaller still and are high in cholesterol; and hdl are the smallest and are rich in protein. -small intestine stomach short-chain fatty acids medium-chain fatty acids glycerol chylomicrons capillary network lacteal (lymph) blood vessels via blood to liver glycerol and small lipids such as short- and medium-chain fatty acids can move directly into the bloodstream. -the transport of cholesterol from the tissues to the liver is sometimes called the scavenger pathway. -to help you remember, think of elevated hdl as healthy and elevated ldl as less healthy. -factors that lower ldl or raise hdl: weight control monounsaturated or polyunsaturated, instead of saturated, fat in the diet soluble, viscous fibers (see chapter 4) phytochemicals (see highlight 13) moderate alcohol consumption physical activity hdl (high-density lipoprotein): the type of lipoprotein that transports cholesterol back to the liver from the cells; composed primarily of protein. -figure 5-18 sizes and compositions of the lipoproteins the lipids: triglycerides, phospholipids, and sterols 153 phospholipid cholesterol triglyceride protein a typical lipoprotein contains an interior of triglycerides and cholesterol surrounded by phospholipids. -the phospholipids fatty acid tails point towards the interior, where the lipids are. -proteins near the outer ends of the phospholipids cover the structure. -this arrangement of hydrophobic molecules on the inside and hydrophilic molecules on the outside allows lipids to travel through the watery fluids of the blood. -protein cholesterol phospholipid triglyceride t n e c r e p 100 80 60 40 20 0 chylomicron ldl vldl hdl this solar system of lipoproteins shows their relative sizes. -notice how large the fat-filled chylomicron is compared with the others and how the others get progressively smaller as their proportion of fat declines and protein increases. -chylomicron vldl ldl hdl chylomicrons contain so little protein and so much triglyceride that they are the lowest in density. -very-low-density lipoproteins (vldl) are half triglycerides, accounting for their very low density. -low-density lipoproteins (ldl) are half cholesterol, accounting for their implication in heart disease. -high-density lipoproteins (hdl) are half protein, accounting for their high density. -lipids in the body the blood carries lipids to various sites around the body. -once lipids arrive at their destinations, they can get to work providing energy, insulating against temperature extremes, protecting against shock, and maintaining cell membranes. -this section provides an overview of the roles of triglycerides and fatty acids and then of the metabolic pathways they can follow within the body s cells. -roles of triglycerides first and foremost, the triglycerides either from food or from the body s fat stores provide the body with energy. -when a person dances all night, her dinner s triglyc- erides provide some of the fuel that keeps her moving. -when a person loses his appetite, his stored triglycerides fuel much of his body s work until he can eat again. -efficient energy metabolism depends on the energy nutrients carbohydrate, fat, and protein supporting each other. -glucose fragments combine with fat fragments during energy metabolism, and fat and carbohydrate help spare pro- tein, providing energy so that protein can be used for other important tasks. -154 chapter 5 figure 5-19 omega-6 fatty acid to another the pathway from one fat also insulates the body. -fat is a poor conductor of heat, so the layer of fat be- neath the skin helps keep the body warm. -fat pads also serve as natural shock ab- sorbers, providing a cushion for the bones and vital organs. -linoleic acid (18:2) desaturation (18:3) (20:3) elongation desaturation arachidonic acid (20:4) the first number indicates the number of carbons and the second, the number of double bonds. -similar reactions occur when the body makes the omega-3 fatty acids epa and dha from linolenic acid. -a nonessential nutrient (such as arachidonic acid) that must be supplied by the diet in special circumstances (as in a linoleic acid deficiency) is considered conditionally essential. -essential fatty acids: fatty acids needed by the body but not made by it in amounts sufficient to meet physiological needs. -arachidonic (a-rack-ih-don-ic) acid: an omega-6 polyunsaturated fatty acid with 20 carbons and four double bonds; present in small amounts in meat and other animal products and synthesized in the body from linoleic acid. -eicosapentaenoic (eye-cossa-penta-ee-no- ick) acid (epa): an omega-3 polyunsaturated fatty acid with 20 carbons and five double bonds; present in fish and synthesized in limited amounts in the body from linolenic acid. -docosahexaenoic (doe-cossa-hexa-ee-no- ick) acid (dha): an omega-3 polyunsaturated fatty acid with 22 carbons and six double bonds; present in fish and synthesized in limited amounts in the body from linolenic acid. -eicosanoids (eye-coss-uh-noyds): derivatives of 20-carbon fatty acids; biologically active compounds that help to regulate blood pressure, blood clotting, and other body functions. -they include prostaglandins (pros-tah-gland-ins), thromboxanes (throm-box-ains), and leukotrienes (loo-ko-try-eens). -essential fatty acids the human body needs fatty acids, and it can make all but two of them linoleic acid (the 18-carbon omega-6 fatty acid) and linolenic acid (the 18-carbon omega-3 fatty acid). -these two fatty acids must be supplied by the diet and are therefore es- sential fatty acids. -a simple definition of an essential nutrient has already been given: a nutrient that the body cannot make, or cannot make in sufficient quanti- ties to meet its physiological needs. -the cells do not possess the enzymes to make any of the omega-6 or omega-3 fatty acids from scratch, nor can they convert an omega-6 fatty acid to an omega-3 fatty acid or vice versa. -cells can, however, start with the 18-carbon member of an omega family and make the longer fatty acids of that family by forming double bonds (desaturation) and lengthening the chain two carbons at a time (elongation), as shown in figure 5-19. this is a slow process be- cause the omega-3 and omega-6 families compete for the same enzymes. -too much of a fatty acid from one family can create a deficiency of the other family s longer fatty acids, which is critical only when the diet fails to deliver adequate supplies. -therefore, the most effective way to maintain body supplies of all the omega-6 and omega-3 fatty acids is to obtain them directly from foods most notably, from veg- etable oils, seeds, nuts, fish, and other marine foods. -linoleic acid and the omega-6 family linoleic acid is the primary member of the omega-6 family. -when the body receives linoleic acid from the diet, it can make other members of the omega-6 family such as the 20-carbon polyunsatu- rated fatty acid, arachidonic acid. -if a linoleic acid deficiency should develop, arachidonic acid, and all other fatty acids that derive from linoleic acid, would also become essential and have to be obtained from the diet. -normally, vegetable oils and meats supply enough omega-6 fatty acids to meet the body s needs. -linolenic acid and the omega-3 family linolenic acid is the primary mem- ber of the omega-3 family. -* like linoleic acid, linolenic acid cannot be made in the body and must be supplied by foods. -given this 18-carbon fatty acid, the body can make small amounts of the 20- and 22-carbon members of the omega-3 series, eicosapentaenoic acid (epa) and docosahexaenoic acid (dha). -these omega-3 fatty acids are essential for normal growth and development, especially in the eyes and brain.4 they may also play an important role in the prevention and treatment of heart disease. -eicosanoids the body uses arachidonic acid and epa to make substances known as eicosanoids. -eicosanoids are a diverse group of compounds that are sometimes described as hormonelike, but they differ from hormones in important ways. -for one, hormones are secreted in one location and travel to affect cells all over the body, whereas eicosanoids appear to affect only the cells in which they are made or nearby cells in the same localized environment. -for another, hormones elicit the same response from all their target cells, whereas eicosanoids often have different ef- fects on different cells. -the actions of various eicosanoids sometimes oppose each other. -for example, one causes muscles to relax and blood vessels to dilate, whereas another causes muscles to contract and blood vessels to constrict. -certain eicosanoids participate in the immune response to injury and infection, producing fever, inflammation, and pain. -one of the ways aspirin relieves these symptoms is by slowing the syn- thesis of these eicosanoids. -* this omega-3 linolenic acid is known as alpha-linolenic acid and is the fatty acid referred to in this chapter. -another fatty acid, also with 18 carbons and three double bonds, belongs to the omega-6 fam- ily and is known as gamma-linolenic acid. -the lipids: triglycerides, phospholipids, and sterols 155 eicosanoids that derive from epa differ from those that derive from arachidonic acid, with those from epa providing greater health benefits.5 the epa eicosanoids help lower blood pressure, prevent blood clot formation, protect against irregular heartbeats, and reduce inflammation. -because the omega-6 and omega-3 fatty acids compete for the same enzymes to make arachidonic acid and epa and to make the eicosanoids, the body needs these long-chain polyunsaturated fatty acids from the diet to make eicosanoids in sufficient quantities.6 fatty acid deficiencies most diets in the united states and canada meet the minimum essential fatty acid requirement adequately. -historically, deficiencies have developed only in infants and young children who have been fed fat-free milk and low-fat diets or in hospital clients who have been mistakenly fed formulas that provided no polyunsaturated fatty acids for long periods of time. -classic deficiency symptoms include growth retardation, reproductive failure, skin lesions, kidney and liver disorders, and subtle neurological and visual problems. -interestingly, a deficiency of omega-3 fatty acids (epa and dha) may be associ- ated with depression.7 some neurochemical pathways in the brain become more ac- tive and others become less active.8 it is unclear, however, which comes first whether inadequate intake alters brain activity or depression alters fatty acid metabolism. -to find the answers, researchers must untangle a multitude of confounding factors. -in summary in the body, triglycerides: provide an energy reserve when stored in the body s fat tissue insulate against temperature extremes protect against shock help the body use carbohydrate and protein efficiently linoleic acid (18 carbons, omega-6) and linolenic acid (18 carbons, omega-3) are essential nutrients. -they serve as structural parts of cell membranes and as precursors to the longer fatty acids that can make eicosanoids powerful com- pounds that participate in blood pressure regulation, blood clot formation, and the immune response to injury and infection, among other functions. -be- cause essential fatty acids are common in the diet and stored in the body, de- ficiencies are unlikely. -s e g a m i y t t e g / i x a t / s n i m m u c m i j double thanks: the body s fat stores provide energy for a walk, and the heel s fat pads cush- ion against the hard pavement. -figure 5-20 an adipose cell newly imported triglycerides first form small droplets at the periphery of the cell, then merge with the large, central globule. -large central globule of (pure) fat cell nucleus a preview of lipid metabolism the blood delivers triglycerides to the cells for their use. -this is a preview of how the cells store and release energy from fat; chapter 7 provides details. -storing fat as fat the triglycerides, familiar as the fat in foods and as body fat, serve the body primarily as a source of fuel. -fat provides more than twice the energy of carbohydrate and protein, making it an extremely efficient storage form of en- ergy. -unlike the liver s glycogen stores, the body s fat stores have virtually unlimited capacity, thanks to the special cells of the adipose tissue. -unlike most body cells, which can store only limited amounts of fat, the fat cells of the adipose tissue read- ily take up and store fat. -an adipose cell is depicted in figure 5-20. to convert food fats to body fat, the body simply breaks them down, absorbs the parts, and puts them (and others) together again in storage. -it requires very little energy to do this. -an enzyme lipoprotein lipase (lpl) hydrolyzes triglyc- erides from lipoproteins, producing glycerol, fatty acids, and monoglycerides that enter the adipose cells. -inside the cells, other enzymes reassemble the pieces into triglycerides again for storage. -earlier, figure 5-4 (p. 143) showed how the body can make a triglyceride from glycerol and fatty acids. -triglycerides fill the adipose cells, storing a lot of energy in a relatively small space. -adipose cells store fat cytoplasm as the central globule enlarges, the fat cell membrane expands to accommodate its swollen contents. -reminder: gram for gram, fat provides more than twice as much energy (9 kcal) as carbo- hydrate or protein (4 kcal). -adipose (add-ih-poce) tissue: the body s fat tissue; consists of masses of triglyceride- storing cells. -lipoprotein lipase (lpl): an enzyme that hydrolyzes triglycerides passing by in the bloodstream and directs their parts into the cells, where they can be metabolized for energy or reassembled for storage. -156 chapter 5 fat supplies most of the energy during a long- distance run. -1 lb body fat = 3500 kcal after meals when a heavy traffic of chylomicrons and vldl loaded with triglyc- erides passes by; they release it later whenever the other cells need replenishing. -using fat for energy fat supplies 60 percent of the body s ongoing energy needs during rest. -during prolonged light to moderately intense exercise or extended peri- ods of food deprivation, fat stores may make a slightly greater contribution to en- ergy needs. -when cells demand energy, an enzyme (hormone-sensitive lipase) inside the adipose cells responds by dismantling stored triglycerides and releasing the glycerol and fatty acids directly into the blood. -energy-hungry cells anywhere in the body can then capture these compounds and take them through a series of chemical reactions to yield energy, carbon dioxide, and water. -a person who fasts (drinking only water) will rapidly metabolize body fat. -a pound of body fat provides 3500 kcalories, so you might think a fasting person who expends 2000 kcalories a day could lose more than half a pound of body fat each day. -* actually, the person has to obtain some energy from lean tissue because the brain, nerves, and red blood cells need glucose. -also, the complete breakdown of fat requires carbohydrate or protein. -even on a total fast, a person cannot lose more than half a pound of pure fat per day. -still, in conditions of enforced starva- tion say, during a siege or a famine a fatter person can survive longer than a thinner person thanks to this energy reserve. -although fat provides energy during a fast, it can provide very little glucose to give energy to the brain and nerves. -only the small glycerol molecule can be con- verted to glucose; fatty acids cannot be. -(figure 7-12 on p. 224 illustrates how only 3 of the 50 or so carbon atoms in a molecule of fat can yield glucose.) -after pro- longed glucose deprivation, brain and nerve cells develop the ability to derive about two-thirds of their minimum energy needs from the ketone bodies that the body makes from fat fragments. -ketone bodies cannot sustain life by themselves, however. -as chapter 7 explains, fasting for too long will cause death, even if the person still has ample body fat. -s e g a m i y t t e g / e n o t s / s a m o h t b o b in summary the body can easily store unlimited amounts of fat if given excesses, and this body fat is used for energy when needed. -(remember that the liver can also convert excess carbohydrate and protein into fat.) -fat breakdown requires si- multaneous carbohydrate breakdown for maximum efficiency; without carbo- hydrate, fats break down to ketone bodies. -desirable blood lipid profile: total cholesterol: (cid:3)200 mg/dl ldl cholesterol: (cid:3)100 mg/dl hdl cholesterol: (cid:4)60 mg/dl triglycerides: (cid:3)150 mg/dl hormone-sensitive lipase: an enzyme inside adipose cells that responds to the body s need for fuel by hydrolyzing triglycerides so that their parts (glycerol and fatty acids) escape into the general circulation and thus become available to other cells for fuel. -the signals to which this enzyme responds include epinephrine and glucagon, which oppose insulin (see chapter 4). -blood lipid profile: results of blood tests that reveal a person s total cholesterol, triglycerides, and various lipoproteins. -health effects and recommended intakes of lipids of all the nutrients, fat is most often linked with heart disease, some types of cancer, and obesity. -fortunately, the same recommendation can help with all of these health problems: choose a diet that is low in saturated fats, trans fats, and cholesterol and moderate in total fat. -health effects of lipids hearing a physician say, your blood lipid profile looks fine, is reassuring. -the blood lipid profile reveals the concentrations of various lipids in the blood, * the reader who knows that 1 pound = 454 grams and that 1 gram of fat = 9 kcalories may wonder why a pound of body fat does not equal 4086 (9 (cid:5) 454) kcalories. -the reason is that body fat contains some cell water and other materials; it is not quite pure fat. -the lipids: triglycerides, phospholipids, and sterols 157 notably triglycerides and cholesterol, and their lipoprotein carriers (vldl, ldl, and hdl). -this information alerts people to possible disease risks and perhaps to a need for changing their exercise and eating habits. -both the amounts and types of fat in the diet influence people s risk for disease.9 heart disease most people realize that elevated blood cholesterol is a major risk factor for cardiovascular disease. -cholesterol accumulates in the arteries, re- stricting blood flow and raising blood pressure. -the consequences are deadly; in fact, heart disease is the nation s number one killer of adults. -blood cholesterol level is of- ten used to predict the likelihood of a person s suffering a heart attack or stroke; the higher the cholesterol, the earlier and more likely the tragedy. -much of the effort to prevent heart disease focuses on lowering blood cholesterol. -commercials advertise products that are low in cholesterol, and magazine arti- cles tell readers how to cut the cholesterol from their favorite recipes. -what most people don t realize, though, is that food cholesterol does not raise blood cholesterol as dramatically as saturated fat does. -risks from saturated fats as mentioned earlier, ldl cholesterol raises the risk of heart disease. -saturated fats are most often implicated in raising ldl cholesterol. -in general, the more saturated fat in the diet, the more ldl cholesterol in the body. -not all saturated fats have the same cholesterol-raising effect, however. -most no- table among the saturated fatty acids that raise blood cholesterol are lauric, myris- tic, and palmitic acids (12, 14, and 16 carbons, respectively). -in contrast, stearic acid (18 carbons) does not seem to raise blood cholesterol. -however, making such distinc- tions may be impractical in diet planning because these saturated fatty acids typi- cally appear together in the same foods. -fats from animal sources are the main sources of saturated fats in most peo- ple s diets (see figure 5-21). -some vegetable fats (coconut and palm) and hydro- genated fats provide smaller amounts of saturated fats. -selecting poultry or fish and fat-free milk products helps to lower saturated fat intake and heart disease risk. -using nonhydrogenated margarine and unsaturated cooking oil is another simple change that can dramatically lower saturated fat intake. -risks from trans fats research also suggests an association between dietary trans-fatty acids and heart disease.10 in the body, trans-fatty acids alter blood choles- terol the same way some saturated fats do: they raise ldl cholesterol and, at high intakes, lower hdl cholesterol.11 trans-fatty acids also appear to increase inflamma- tion and insulin resistance.12 limiting the intake of trans-fatty acids can improve blood cholesterol and lower the risk of heart disease. -the estimated average intake of trans-fatty acids in the united states is about 5 grams per day mostly from prod- ucts that have been hydrogenated.13 reports on trans-fatty acids have raised consumer doubts about whether mar- garine is, after all, a better choice than butter for heart health. -the american heart association has stated that because butter is rich in both saturated fat and choles- terol whereas margarine is made from vegetable fat with no dietary cholesterol, margarine is still preferable to butter. -be aware that soft margarines (liquid or tub) are less hydrogenated and relatively lower in trans-fatty acids; consequently, they do not raise blood cholesterol as much as the saturated fats of butter or the trans fats of hard (stick) margarines do. -some manufacturers are now offering nonhydro- genated margarines that are trans fat free. -the last section of this chapter de- scribes how to read food labels and compares butter and margarines. -whichever you decide to use, remember to use them sparingly. -risks from cholesterol although its effect is not as strong as that of saturated fat or trans fat, dietary cholesterol also raises blood cholesterol and increases the risk of heart disease. -to maximize the effect on blood cholesterol, limit dietary cholesterol as well. -recall that cholesterol is found in all foods derived from animals. -consequently, eating less fat from meats, eggs, and milk products helps lower dietary cholesterol in- take (as well as total and saturated fat intakes). -figure 5-22 (p. 158) shows the figure 5-21 u.s. diet milk, yogurt, and cheese 20% saturated fats in the other 2% eggs 2% nuts and legumes 2% added fats and oils 34% meat, poultry, and fish 40% note that fruits, grains, and vegetables are insignificant sources, unless saturated fats are intentionally added to them during preparation. -major sources of saturated fats: whole milk, cream, butter, cheese fatty cuts of beef and pork coconut, palm, and palm kernel oils (and products containing them such as candies, pastries, pies, doughnuts, and cookies) major sources of trans fats: deep-fried foods (vegetable shortening) cakes, cookies, doughnuts, pastry, crackers snack chips margarine imitation cheese meat and dairy products when selecting margarine, look for: soft (liquid or tub) instead of hard (stick) (cid:6)2 g saturated fat liquid vegetable oil (not hydrogenated or partially hydrogenated) as first ingredient trans fat free major sources of cholesterol: eggs milk products meat, poultry, shellfish cardiovascular disease (cvd): a general term for all diseases of the heart and blood vessels. -atherosclerosis is the main cause of cvd. -when the arteries that carry blood to the heart muscle become blocked, the heart suffers damage known as coronary heart disease (chd). -cardio = heart vascular = blood vessels 158 chapter 5 sources of monounsaturated fats: olive oil, canola oil, peanut oil avocados sources of polyunsaturated fats: vegetable oils (safflower, sesame, soy, corn, sunflower) nuts and seeds major sources of omega-3 fats: vegetable oils (canola, soybean, flaxseed) walnuts, flaxseeds fatty fish (mackerel, salmon, sardines) figure 5-22 cholesterol in selected foods cholesterol contents of selected foods. -many more foods, with their cholesterol con- tents, appear in appendix h. for most people trying to lower blood cholesterol, however, limiting saturated fat is more effective than limiting cholesterol intake. -most foods that are high in cholesterol are also high in saturated fat, but eggs are an exception. -an egg contains only 1 gram of saturated fat but just over 200 milligrams of cholesterol roughly two-thirds of the recommended daily limit. -for people with a healthy lipid profile, eating one egg a day is not detrimental. -people with high blood cholesterol, however, may benefit from limiting daily cholesterol intake to less that 200 milligrams.14 when eggs are included in the diet, other sources of cholesterol may need to be limited on that day. -eggs are a valuable part of the diet because they are inexpensive, useful in cooking, and a source of high- quality protein and other nutrients. -low saturated fat, high omega-3 fat eggs are now available, and food manufacturers have produced several fat-free, cholesterol- free egg substitutes. -benefits from monounsaturated fats and polyunsaturated fats replac- ing both saturated and trans fats with monounsaturated and polyunsaturated fats may be the most effective dietary strategy in preventing heart disease. -the lower rate of heart disease among people in the mediterranean region of the world is of- ten attributed to their liberal use of olive oil, a rich source of monounsaturated fatty acids. -olive oil also delivers valuable phytochemicals that help to protect against heart disease.15 replacing saturated fats with the polyunsaturated fatty acids of other vegetable oils also lowers blood cholesterol.16 highlight 5 examines various types of fats and their roles in supporting or harming heart health. -benefits from omega-3 fats research on the different types of fats has spot- lighted the beneficial effects of the omega-3 polyunsaturated fatty acids in reduc- ing the risks of heart disease and stroke.17 regular consumption of omega-3 fatty acids helps to prevent blood clots, protect against irregular heartbeats, and lower blood pressure, especially in people with hypertension or atherosclerosis.18 fatty fish are among the best sources of omega-3 fatty acids, and highlight 5 features their role in supporting heart health. -chapter 19 discusses the adverse con- food milk milk yogurt, plain yogurt, plain cheddar cheese cottage cheese swiss cheese ice cream butter shrimp serving size (kcalories) 1 c whole (150 kcal) 1 c reduced-fat 2% (121 kcal) 1 c whole (150 kcal) 1 c low-fat (155 kcal) 11 2 oz (170 kcal) 1 2 c reduced-fat 2% (101 kcal) 11 2 oz (140 kcal) 1 2 c, 10% fat (133 kcal) 1 tsp (36 kcal) 3 oz boiled (85 kcal) ground beef, lean 3 oz broiled (237 kcal) chicken breast 3 oz roasted (141 kcal) cod ham, lean sirloin steak, lean tuna, canned in water 3 oz poached (88 kcal) 3 oz roasted (123 kcal) 3 oz broiled (171 kcal) 3 oz (99 kcal) bologna, beef 2 slices (144 kcal) egg 1 hard cooked (77 kcal) 0 60 120 180 240 300 milligrams cholesterol only foods of animal origin contain significant cholesterol. -consequently, grains, vegetables, legumes, and fruits provide virtually no cholesterol. -daily value key: milk and milk products meats miscellaneous the lipids: triglycerides, phospholipids, and sterols 159 table 5-2 sources of omega-3 and omega-6 fatty acids omega-6 linoleic acid vegetable oils (corn, sunflower, safflower, soybean, cottonseed), poultry fat, nuts, seeds arachidonic acid meats, poultry, eggs (or can be made from linoleic acid) omega-3 linolenic acid epa and dha oils (flaxseed, canola, walnut, wheat germ, soybean) nuts and seeds (butternuts, flaxseeds, walnuts, soybean kernels) vegetables (soybeans) human milk pacific oysters and fisha (mackerel, salmon, bluefish, mullet, sablefish, menhaden, anchovy, herring, lake trout, sardines, tuna) (or can be made from linolenic acid) aall fish contain some epa and dha; the amounts vary among species and within a species depending on such factors as diet, season, and environment. -the fish listed here, except tuna, provide at least 1 gram of omega-3 fatty acids in 100 grams of fish (3.5 ounces). -tuna provides fewer omega-3 fatty acids, but because it is commonly consumed, its contribution can be significant. -sequences of mercury, an environmental contaminant common in some fish. -to maximize the benefits and minimize the risks, most healthy people should eat two servings of fish a week.19 balance omega-6 and omega-3 intakes table 5-2 provides sources of omega-6 and omega-3 fatty acids. -to obtain sufficient intakes and the right balance between omega-6 and omega-3 fatty acids, most people need to eat more fish and less meat.20 the american heart association recommends two servings of fish a week, with an emphasis on fatty fish (salmon, herring, and mackerel, for exam- ple).21 eating fish instead of meat supports heart health, especially when combined with physical activity. -even one fish meal a month may be enough to make a differ- ence.22 when preparing fish, grill, bake, or broil, but do not fry. -fried fish from fast- food restaurants and frozen fried fish products are often low in omega-3 fatty acids and high in trans- and saturated fatty acids. -fish provides many minerals (except iron) and vitamins and is leaner than most other animal-protein sources. -when used in a weight-loss program, eating fish improves blood lipids even more effec- tively than can be explained by losing weight or eating fish alone. -in addition to fish, other functional foods are being developed to help con- sumers improve their omega-3 fatty acid intake. -for example, hens fed flaxseed produce eggs rich in omega-3 fatty acids. -including even one enriched egg in the diet daily can significantly increase a person s intake of omega-3 fatty acids. -an- other option may be to select wild game or pasture-fed cattle, which provide more omega-3 fatty acids and less saturated fat than grain-fed cattle.23 omega-3 fatty acids are also available in capsules of fish oil supplements. -rou- tine supplementation, however, is not recommended. -high intakes of omega-3 polyunsaturated fatty acids may increase bleeding time, interfere with wound healing, raise ldl cholesterol, and suppress immune function. -* 24 such findings re- inforce the concept that too much of a good thing can sometimes be harmful. -peo- ple with heart disease, however, may benefit from doses greater than can be achieved through diet alone. -they should always consult a physician first because including supplements as part of a treatment plan may be contraindicated for some patients.25 supplements may also provide relief for people with rheumatoid arthritis or asthma.26 cancer the evidence for links between dietary fats and cancer is less convincing than for heart disease, but it does suggest possible associations between some types * suppressed immune function is seen with daily intake of 0.9 to 9.4 grams epa and 0.6 to 6.0 grams dha for 3 to 24 weeks. -fish relatively high in mercury: tilefish (also called golden snapper or golden bass), swordfish, king mackerel, shark fish relatively low in mercury: cod, haddock, pollock, salmon, sole, tilapia most shellfish recommended omega-6 to omega-3 ratio: 6 to 1 reminder: functional foods contain physiologically active compounds that pro- vide health benefits beyond basic nutrition (see highlight 13 for a full discussion). -other risk factors for cancer include smoking, alcohol, and environmental contaminants. -chapter 18 provides many more details about these risk factors and the development of cancer. -160 chapter 5 fat is a more concentrated energy source than the other energy nutrients: 1 g carbo- hydrate or protein = 4 kcal, but 1 g fat = 9 kcal of fat and some types of cancers.27 dietary fat does not seem to initiate cancer devel- opment but, instead, may promote cancer once it has arisen. -the relationship between dietary fat and the risk of cancer differs for various types of cancers. -in the case of breast cancer, evidence has been weak and inconclusive. -some studies indicate little or no association between dietary fat and breast cancer; others find that total energy intake and obesity contribute to the risk.28 in the case of prostate cancer, some studies indicate a harmful association with total and sat- urated fat, although a specific type fatty acid has not yet been implicated.29 the relationship between dietary fat and the risk of cancer differs for various types of fats as well. -the association between cancer and fat appears to be due pri- marily to saturated fats or dietary fat from meats (which is mostly saturated). -fat from milk or fish has not been implicated in cancer risk.30 in fact, the omega-3 fatty acids of fish may protect against some cancers, although evidence does not support supplementation.31 thus dietary advice to reduce cancer risks parallels that given to reduce heart disease risks: reduce saturated fats and increase omega- 3 fatty acids. -obesity fat contributes more than twice as many kcalories per gram as either carbohydrate or protein. -consequently, people who eat high-fat diets regularly may exceed their energy needs and gain weight, especially if they are inactive.32 because fat boosts energy intake, cutting fat from the diet can be an effective strategy in cut- ting kcalories. -in some cases, though, choosing a fat-free food offers no kcalorie sav- ings. -fat-free frozen desserts, for example, often have so much sugar added that the kcalorie count can be as high as in the regular-fat product. -in this case, therefore, cutting fat and adding carbohydrate offers no kcalorie savings or weight-loss advan- tage. -in fact, it may even raise energy intake and exacerbate weight problems. -later chapters revisit the role of dietary fat in the development of obesity. -in summary high blood ldl cholesterol poses a risk of heart disease, and high intakes of saturated and trans fats, specifically, contribute most to high ldl. -cholesterol in foods presents less of a risk. -omega-3 fatty acids appear to be protective. -dri and 2005 dietary guidelines for fat: 20 to 35% of energy intake (from mostly polyunsaturated and monounsaturated fat sources such as fish, nuts, and veg- etable oils) linoleic acid (omega-6) ai: men: 19 50 yr: 17 g/day 51+ yr: 14 g/day women: 19 50 yr: 12 g/day 51+ yr: 11 g/day linolenic acid (omega-3) ai: men: 1.6 g/day women: 1.1 g/day daily values: 65 g fat (based on 30% of 2000 kcal diet) 20 g saturated fat (based on 10% of 2000 kcal diet) 300 mg cholesterol recommended intakes of fat some fat in the diet is essential for good health, but too much fat, especially satu- rated fat, increases the risks for chronic diseases. -defining the exact amount of fat, saturated fat, or cholesterol that benefits health or begins to harm health, however, is not possible. -for this reason, no rda or upper limit has been set. -instead, the dri and 2005 dietary guidelines suggest a diet that is low in saturated fat, trans fat, and cholesterol and provides 20 to 35 percent of the daily energy intake from fat. -the top end of this range is slightly higher than previous recommendations. -this revi- sion recognizes that diets with up to 35 percent of kcalories from fat can be compat- ible with good health if energy intake is reasonable and saturated fat intake is low. -when total fat exceeds 35 percent, saturated fat increases to unhealthy levels.33 for a 2000-kcalorie diet, 20 to 35 percent represents 400 to 700 kcalories from fat (roughly 45 to 75 grams). -part of this fat allowance should provide for the essential fatty acids linoleic acid and linolenic acid. -for this reason, an adequate intake (ai) has been established for these two fatty acids. -recommendations suggest that linoleic acid provide 5 to 10 percent of the daily energy intake and linolenic acid 0.6 to 1.2 percent. -34 to help consumers meet the dietary fat goals, the food and drug administration (fda) established daily values on food labels using 30 percent of energy intake as the guideline for fat and 10 percent for saturated fat. -the daily value for choles- the lipids: triglycerides, phospholipids, and sterols 161 terol is 300 milligrams regardless of energy intake. -there is no daily value for trans fat, but consumers should try to keep intakes as low as possible and within the 10 percent allotted for saturated fat. -according to surveys, adults in the united states receive about 33 percent of their total energy from fat, with saturated fat contribut- ing about 11 percent of the total. -cholesterol intakes in the united states average 190 milligrams a day for women and 290 for men. -35 dietary guidelines for americans 2005 consume less than 10 percent of kcalories from saturated fatty acids and less than 300 mg/day of cholesterol, and keep trans fatty acid consump- tion as low as possible. -the fats of fish, nuts, and vegetable oils are not counted as discretionary kcalo- ries because they provide valuable omega-3 fatty acids, essential fatty acids, and vitamin e. in contrast, solid fats deliver an abundance of saturated fatty acids; the usda food guide counts them as discretionary kcalories. -discretionary kcalo- ries may be used to add fats in cooking or at the table or to select higher fat items from the food groups. -although it is very difficult to do, some people actually manage to eat too little fat to their detriment. -among them are people with eating disorders, described in highlight 8, and athletes. -athletes following a diet too low in fat (less than 20 per- cent of total kcalories) fall short on energy, vitamins, minerals, and essential fatty acids as well as on performance.36 as a practical guideline, it is wise to include the equivalent of at least a teaspoon of fat in every meal a little peanut butter on toast or mayonnaise on tuna, for example. -dietary recommendations that limit fat were developed for healthy people over age two; chapter 16 discusses the fat needs of infants and young children. -as the photos in figure 5-23 show (p. 162), fat accounts for much of the energy in foods, and removing the fat from foods cuts energy and saturated fat intakes dramatically. -to reduce dietary fat, eliminate fat as a seasoning and in cooking; re- move the fat from high-fat foods; replace high-fat foods with low-fat alternatives; and emphasize whole grains, fruits, and vegetables. -the remainder of this chapter identifies sources of fat in the diet, food group by food group. -from guidelines to groceries fats accompany protein in foods derived from animals, such as meat, fish, poultry, and eggs, and fats accompany carbohydrate in foods derived from plants, such as av- ocados and coconuts. -fats carry with them the four fat-soluble vitamins a, d, e, and k together with many of the compounds that give foods their flavor, texture, and palatability. -fat is responsible for the delicious aromas associated with sizzling bacon and hamburgers on the grill, onions being saut ed, or vegetables in a stir-fry. -of course, these wonderful characteristics lure people into eating too much from time to time. -with careful selections, a diet following the usda food guide can support good health and still meet fat recommendations (see the how to feature on p. 163). -meats and meat alternates many meats and meat alternates contain fat, saturated fat, and cholesterol but also provide high-quality protein and valuable vi- tamins and minerals. -they can be included in a healthy diet if a person makes lean choices and prepares them using the suggestions outlined in the box on p. 163. se- lecting free-range meats from grass-fed instead of grain-fed livestock offers the nu- trient advantages of being lower in fat, and the fat has more polyunsaturated fatty acids, including the omega-3 type. -another strategy to lower blood cholesterol is to prepare meals using soy protein instead of animal protein.37 solid fats include meat and poultry fats (as in poultry skin, luncheon meats, sausage); milk fat (as in whole milk, cheese, butter); shortening (as in fried foods and baked goods); and hard margarines. -the usda food guide amounts of fats that can be included as discretionary kcalories when most food choices are nutrient dense and fat (cid:3) 30% total kcal: 11 g for 1600 kcal diet 15 g for 1800 kcal diet 18 g for 2000 kcal diet 19 g for 2200 kcal diet 22 g for 2400 kcal diet for perspective, 1 tsp oil = 5 g fat and pro- vides about 45 kcal very lean options: chicken (white meat, no skin); cod, flounder, trout; tuna (canned in water); legumes lean options: beef or pork round or loin cuts; chicken (dark meat, no skin); herring or salmon; tuna (canned in oil) medium-fat options: ground beef, eggs, tofu high-fat options: sausage, bacon, luncheon meats, hot dogs, peanut butter, nuts 162 chapter 5 figure 5-23 cutting fat cuts kcalories and saturated fat pork chop with fat (340 kcal, 19 g fat, 7 g saturated fat). -potato with 1 tbs butter and 1 tbs sour cream (350 kcal, 14 g fat, 10 g saturated fat). -whole milk, 1 c (150 kcal, 8 g fat, 5 g saturated fat). -pork chop with fat trimmed off (230 kcal, 9 g fat, 3 g saturated fat). -plain potato (200 kcal, <1 g fat, 0 g saturated fat). -fat-free milk, 1 c (90 kcal, <1 g fat, <1 g saturated fat). ) -l l a ( . -c n i , s o i d u t s a r a l o p fat-free and low-fat options: fat-free or 1% milk or yogurt (plain); fat- free and low-fat cheeses reduced-fat options: 2% milk, low-fat yogurt (plain) high-fat options: whole milk, regular cheeses dietary guidelines for americans 2005 when selecting and preparing meat, poultry, and milk or milk products, make choices that are lean, low-fat, or fat-free. -milks and milk products like meats, milks and milk products should also be selected with an awareness of their fat, saturated fat, and cholesterol contents. -fat- free and low-fat milk products provide as much or more protein, calcium, and other nutrients as their whole-milk versions but with little or no saturated fat. -selecting fermented milk products, such as yogurt, may also help to lower blood cholesterol. -these foods increase the population and activity of bacteria in the colon that fer- ment fibers. -as chapter 4 explained, this action lowers blood cholesterol as fibers bind with bile, thereby increasing excretion, and as bacteria produce short-chain fatty acids that inhibit cholesterol synthesis in the liver.38 vegetables, fruits, and grains choosing vegetables, fruits, whole grains, and legumes also helps lower the saturated fat, cholesterol, and total fat content of the diet. -most vegetables and fruits naturally contain little or no fat. -although avocados and olives are exceptions, most of their fat is unsaturated, which is not harmful to heart health. -most grains contain only small amounts of fat. -consumers need to read food labels, though, because some grain products such as fried taco shells, crois- sants, and biscuits are high in saturated fat, and pastries, crackers, and cookies may be high in trans fats. -similarly, many people add butter, margarine, or cheese sauce the lipids: triglycerides, phospholipids, and sterols 163 how to make heart-healthy choices by food group breads and cereals select breads, cereals, and crackers that are low in saturated and trans fat (for example, bagels instead of croissants). -prepare pasta with a tomato sauce instead of a cheese or cream sauce. -vegetables and fruits enjoy the natural flavor of steamed vegeta- bles (without butter) for dinner and fruits for dessert. -eat at least two vegetables (in addition to a salad) with dinner. -snack on raw vegetables or fruits instead of high-fat items like potato chips. -buy frozen vegetables without sauce. -milk and milk products switch from whole milk to reduced-fat, from reduced-fat to low-fat, and from low- fat to fat-free (nonfat). -use fat-free and low-fat cheeses (such as part-skim ricotta and low-fat mozzarella) instead of regular cheeses. -use fat-free or low-fat yogurt or sour cream choose fish, poultry, or lean cuts of pork or beef; look for unmarbled cuts named round or loin (eye of round, top round, bottom round, round tip, tenderloin, sirloin, center loin, and top loin). -choose processed meats such as lunch meats and hot dogs that are low in satu- rated fat and cholesterol. -trim the fat from pork and beef; remove the skin from poultry. -grill, roast, broil, bake, stir-fry, stew, or braise meats; don t fry. -when possible, place food on a rack so that fat can drain. -use lean ground turkey or lean ground beef in recipes; brown ground meats without added fat, then drain off fat. -select tuna, sardines, and other canned meats packed in water; rinse oil-packed items with hot water to remove much of the fat. -fill kabob skewers with lots of vegetables and slivers of meat; create main dishes and casseroles by combining a little meat, fish, or poultry with a lot of pasta, rice, or vegetables. -instead of regular sour cream. -use legumes often. -use evaporated fat-free milk instead of eat a meatless meal or two daily. -cream. -enjoy fat-free frozen yogurt, sherbet, or ice milk instead of ice cream. -meat and legumes fat adds up quickly, even with lean meat; limit intake to about 6 ounces (cooked weight) daily. -eat at least two servings of fish per week (particularly fish such as mackerel, lake trout, herring, sardines, and salmon). -use egg substitutes in recipes instead of whole eggs or use two egg whites in place of each whole egg. -fats and oils use butter or stick margarine sparingly; select soft margarines instead of hard margarines. -use fruit butters, reduced-kcalorie mar- garines, or butter replacers instead of butter. -use low-fat or fat-free mayonnaise and salad dressing instead of regular. -limit use of lard and meat fat. -limit use of products made with coconut oil, palm kernel oil, and palm oil (read labels on bakery goods, processed foods, popcorn oils, and nondairy creamers). -reduce use of hydrogenated shortenings and stick margarines and products that contain them (read labels on crackers, cookies, and other commercially prepared baked goods); use vegetable oils instead. -miscellaneous use a nonstick pan or coat the pan lightly with vegetable oil. -refrigerate soups and stews; when the fat solidifies, remove it. -use wine; lemon, orange, or tomato juice; herbs; spices; fruits; or broth instead of butter or margarine when cooking. -stir-fry in a small amount of oil; add mois- ture and flavor with broth, tomato juice, or wine. -use variety to enhance enjoyment of the meal: vary colors, textures, and tempera- tures hot cooked versus cool raw foods and use garnishes to complement food. -omit high-fat meat gravies and cheese sauces. -source: adapted from third report of the national cholesterol education program (ncep) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel iii), nih publication no. -02-5215 (bethesda, md. -: national heart, lung, and blood institute, 2002), pp. -v-25 v-27. -to grains and vegetables, which raises their saturated and trans fat contents. -because fruits are often eaten without added fat, a diet that includes several servings of fruit daily can help a person meet the dietary recommendations for fat. -a diet rich in vegetables, fruits, whole grains, and legumes also offers abundant vitamin c, folate, vitamin a, vitamin e, and dietary fiber all important in sup- porting health. -consequently, such a diet protects against disease by reducing sat- urated fat, cholesterol, and total fat as well as by increasing nutrients. -it also provides valuable phytochemicals that help defend against heart disease. -invisible fat visible fat, such as butter and the fat trimmed from meat, is easy to see. -invisible fat is less apparent and can be present in foods in surprising amounts. -invisible fat marbles a steak or is hidden in foods like cheese. -any fried food con- tains abundant fat potato chips, french fries, fried wontons, and fried fish. -many baked goods, too, are high in fat pie crusts, pastries, crackers, biscuits, cornbread, doughnuts, sweet rolls, cookies, and cakes. -most chocolate bars deliver more kcalo- ries from fat than from sugar. -even cream-of-mushroom soup prepared with water derives 66 percent of its energy from fat. -keep invisible fats in mind when making food selections. -164 chapter 5 well-balanced, healthy meals provide some fat with an emphasis on monounsaturated and polyunsaturated fats. -fat replacers: ingredients that replace some or all of the functions of fat and may or may not provide energy. -artificial fats: zero-energy fat replacers that are chemically synthesized to mimic the sensory and cooking qualities of naturally occurring fats but are totally or partially resistant to digestion. -olestra: a synthetic fat made from sucrose and fatty acids that provides 0 kcalories per gram; also known as sucrose polyester. -choose wisely consumers can find an abundant array of foods that are low in saturated fat, trans fat, cholesterol, and total fat. -in many cases, they are familiar foods that are simply prepared with less fat. -for example, fat can be removed by skimming milk or trimming meats. -manufacturers can dilute fat by adding water or whipping in air. -they can use fat-free milk in creamy desserts and lean meats in frozen entr es. -sometimes manufacturers simply prepare the products differently. -for example, fat-free potato chips may be baked instead of fried. -beyond lowering the fat content, manufacturers have developed margarines fortified with plant sterols that lower blood cholesterol. -* 39 (highlight 13 explores these and other func- tional foods designed to support health.) -such choices make heart-healthy eating easy. -. -c n i s o i d u t s a r a l o p dietary guidelines for americans 2005 limit intakes of fats and oils high in saturated and/or trans fatty acids, and choose products low in such fats and oils. -to replace saturated fats with unsaturated fats, saut foods in olive oil instead of butter, garnish salads with sunflower seeds instead of bacon, snack on mixed nuts instead of potato chips, use avocado instead of cheese on a sandwich, and eat salmon instead of steak. -table 5-3 shows how these simple substitutions can lower the saturated fat and raise the unsaturated fat in a meal. -highlight 5 provides more details about the benefits of healthy fats in the diet. -fat replacers some foods are made with fat replacers ingredients derived from carbohydrate, protein, or fat that can be used to replace some or all of the fat in foods. -the body may digest and absorb some of these substances, so they may contribute some energy, although significantly less energy than fat s 9 kcalories per gram. -fat replacers offering the sensory and cooking qualities of fats but none of the kcalories are called artificial fats. -a familiar example of an artificial fat that has been approved for use in snack foods such as potato chips, crackers, and tortilla chips is olestra. -olestra s chemical structure is similar to that of a regular fat (a triglyceride) but with important differences. -a triglyceride is composed of a glycerol molecule with three fatty acids attached, whereas olestra is made of a sucrose mol- * margarines that lower blood cholesterol contain plant sterols and are marketed under the brand names benecol and take control. -table 5-3 choosing unsaturated fat instead of saturated fat portion sizes have been adjusted so that each of these foods provides approximately 100 kcalories. -notice that for a similar number of kcalories and grams of fat, the first choices offer less saturated fat and more unsaturated fat. -foods (100 kcal portions) saturated fat (g) unsaturated fat (g) olive oil (1tbs) vs. butter (1tbs) 2 vs. 7 sunflower seeds (2 tbs) vs. bacon (2 slices) 1 vs. 3 mixed nuts (2 tbs) vs. potato chips (10 chips) 1 vs. 2 avocado (6 slices) vs. cheese (1 slice) salmon (2 oz) vs. steak (11/2 oz) totals 2 vs. 4 1 vs. 2 7 vs. 18 9 vs. 4 7 vs. 6 8 vs. 5 8 vs. 4 3 vs. 3 total fat (g) 11 vs. 11 8 vs. 9 9 vs. 7 10 vs. 8 4 vs. 5 35 vs. 22 42 vs. 40 the lipids: triglycerides, phospholipids, and sterols 165 ecule with six to eight fatty acids attached. -enzymes in the digestive tract cannot break the bonds of olestra, so unlike sucrose or fatty acids, olestra passes through the system unabsorbed. -the fda s evaluation of olestra s safety addressed two questions. -first, is olestra toxic? -research on both animals and human beings supports the safety of olestra as a partial replacement for dietary fats and oils, with no re- ports of cancer or birth defects. -second, does olestra affect either nutrient ab- sorption or the health of the digestive tract? -when olestra passes through the digestive tract unabsorbed, it binds with some of the fat-soluble vitamins a, d, e, and k and carries them out of the body, robbing the person of these valu- able nutrients. -to compensate for these losses, the fda requires the manufac- turer to fortify olestra with vitamins a, d, e, and k. saturating olestra with these vitamins does not make the product a good source of vitamins, but it does block olestra s ability to bind with the vitamins from other foods. -an as- terisk in the ingredients list informs consumers that these added vitamins are dietarily insignificant. -some consumers experience digestive distress with olestra consumption, such as cramps, gas, bloating, and diarrhea. -the fda initially required a label warn- ing stating that olestra may cause abdominal cramping and loose stools and that it inhibits the absorption of some vitamins and other nutrients but has since concluded that such a statement is no longer warranted. -consumers need to keep in mind that low-fat and fat-free foods still deliver kcalories. -alternatives to fat can help to lower energy intake and support weight loss only when they actually replace fat and energy in the diet.40 read food labels labels list total fat, saturated fat, trans fat, and cholesterol contents of foods in addition to fat kcalories per serving (see figure 5-24, p. 166). -be- cause each package provides information for a single serving and because serving sizes are standardized, consumers can easily compare similar products. -total fat, saturated fat, and cholesterol are also expressed as % daily values for a person consuming 2000 kcalories. -people who consume more or less than 2000 kcalories daily can calculate their personal daily value for fat as described in the how to below. -trans fats do not have a daily value. -o i g g u r r a f w e h t t a m beware of fast-food meals delivering too much fat, especially saturated fat. -this double bacon cheeseburger, fries, and milkshake provide more than 1600 kcalories, with almost 90 grams of fat and over 30 grams of saturated fat far exceeding dietary fat guidelines for the entire day. -how to calculate a personal daily value for fat the % daily value for fat on food labels is based on 65 grams. -to know how your intake compares with this recommenda- tion, you can either count grams until you reach 65, or add the % daily values until you reach 100 percent if your energy intake is 2000 kcalories a day. -if your en- ergy intake is more or less, you can calcu- late your personal daily fat allowance in grams. -suppose your energy intake is 1800 kcalories per day and your goal is 30 per- cent kcalories from fat. -multiply your total energy intake by 30 percent, then divide by 9: 1800 total kcal (cid:5) 0.30 from fat (cid:2) 540 fat kcal 540 fat kcal (cid:7) 9 kcal/g (cid:2) 60 g fat (in familiar measures, 60 grams of fat is about the same as 2 3 stick of butter or 1 4 cup of oil.) -the accompanying table shows the num- bers of grams of fat allowed per day for various energy intakes. -with one of these numbers in mind, you can quickly evaluate the number of fat grams in foods you are considering eating. -to practice calculating a personal daily value for fat, log on to www.thomsonedu.com/thomsonnow, go to chapter 5, then go to how to. -energy (kcal/day) 20% kcalories from fat 35% kcalories from fat fat (g/day) 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 240 280 320 360 400 440 480 520 560 600 420 490 560 630 700 770 840 910 980 1050 27 47 31 54 36 62 40 70 44 78 49 86 53 93 58 101 62 109 67 117 166 chapter 5 figure 5-24 butter and margarine labels compared food labels list the kcalories from fat; the quantities and daily values for fat, saturated fat, and cholesterol; and the quantities for trans fat. -information on polyunsaturated and monounsaturated fats is optional. -in this example, stick margarine has 2.5 g trans fat and tub margarine has 2 g trans fat. -products that contain 0.5 g or less of trans fat and 0.5 g or less of saturated fat may claim no trans fat. -similarly, products that contain 2 mg or less of cholesterol and 2 g or less of saturated fat may claim to be cholesterol-free. -if the list of ingredients includes hydrogenated oils, you know the food contains trans fat. -chapter 2 explained that foods list their ingredients in descending order of predominance by weight. -as you can see from this example, the closer partially hydro- genated oils is to the beginning of the ingredients list, the more trans fats the product contains. -notice that most of the fat in butter is saturated, whereas most of the fat in margarine is unsaturated; partially hydrogenated margarines tend to have more trans fat than hydrogenated liquid margarines. -butter margarine (stick) margarine (tub) margarine (liquid) nutrition facts serving size 1 tbsp (14g) servings per container about 32 nutrition facts serving size 1 tbsp (14g) servings per container about 32 nutrition facts serving size 1 tbsp (14g) servings per container about 32 nutrition facts serving size 1 tbsp (14g) servings per container about 24 amount per serving amount per serving amount per serving amount per serving calories 100 calories from fat 100 calories 100 calories from fat 100 calories 100 calories from fat 100 calories 70 calories from fat 70 %daily value* %daily value* %daily value* total fat 11g saturated fat 7g trans fat 0g cholesterol 30mg sodium 95mg total carbohydrate 0g protein 0g vitamin a 8% 17% 37% 10% 4% 0% not a significant source of dietary fiber, sugars, vitamin c, calcium, and iron. -*percent daily values are based on a 2,000 calorie diet. -ingredients: cream, salt. -total fat 11g saturated fat 2g trans fat 2.5g polyunsaturated fat 3.5g monounsaturated fat 2.5g cholesterol 0mg sodium 105mg total carbohydrate 0g protein 0g vitamin a 10% 17% 11% 0% 4% 0% total fat 11g saturated fat 2.5g trans fat 2g polyunsaturated fat 4g monounsaturated fat 2.5g cholesterol 0mg sodium 80mg total carbohydrate 0g protein 0g vitamin a 10% 17% 13% 0% 3% 0% total fat 8g saturated fat 1.5g trans fat 0g %daily value* 13% 7% polyunsaturated fat 4.5g monounsaturated fat 2g cholesterol 0mg sodium 110mg total carbohydrate 0g protein 0g vitamin a 10% 0% 8% 0% not a significant source of dietary fiber, sugars, vitamin c, calcium, and iron. -not a significant source of dietary fiber, sugars, vitamin c, calcium, and iron. -not a significant source of dietary fiber, sugars, vitamin c, calcium, and iron. -*percent daily values are based on a 2,000 calorie diet. -*percent daily values are based on a 2,000 calorie diet. -*percent daily values are based on a 2,000 calorie diet. -ingredients: liquid soybean oil, partially hydrogenated soybean oil, water, buttermilk, salt, soy lecithin, sodium benzoate (as a preservative), vegetable mono and diglycerides, artificial flavor, vitamin a palmitate, colored with beta carotene (provitamin a). -ingredients: liquid soybean oil, partially hydrogenated soybean oil, buttermilk, water, butter (cream, salt), salt, soy lecithin, vegetable mono and diglycerides, sodium benzoate added as a preservative, artificial flavor, vitamin a palmitate, colored with beta carotene. -ingredients: liquid soybean oil, water, salt, hydrogenated cottonseed oil, vegetable monoglycerides and soy lecithin (emulsifiers), potassium sorbate and sodium benzoate (to preserve freshness), artificial flavor, phosphoric acid (acidulant), colored with beta carotene (source of vitamin a), vitamin a palmitate. -be aware that the % daily value for fat is not the same as % kcalories from fat. -this important distinction is explained in the how to feature on p. 167. be- cause recommendations apply to average daily intakes rather than individual food items, food labels do not provide % kcalories from fat. -still, you can get an idea of whether a particular food is high or low in fat. -the lipids: triglycerides, phospholipids, and sterols 167 to practice calculating % daily value and % kcalories from fat, log on to www.thomsonedu.com/ thomsonnow, go to chapter 5, then go to how to. -how to understand % daily value and % kcalories from fat the % daily value that is used on food labels to describe the amount of fat in a food is not the same as the % kcalories from fat that is used in dietary recom- mendations to describe the amount of fat in the diet. -they may appear similar, but their difference is worth understanding. -consider, for example, a piece of lemon meringue pie that provides 140 kcalories and 12 grams of fat. -because the daily value for fat is 65 grams for a 2000- kcalorie intake, 12 grams represent about 18 percent: 12 g (cid:7) 65 g (cid:2) 0.18 0.18 (cid:5) 100 (cid:2) 18% the pie s % daily value is 18 percent, or almost one-fifth, of the day s fat al- lowance. -uninformed consumers may mistak- enly believe that this food meets recom- mendations to limit fat to 20 to 35 percent kcalories, but it doesn t for two reasons. -first, the pie s 12 grams of fat contribute 108 of the 140 kcalories, for a total of 77 percent kcalories from fat: s e g a m i y t t e g / c s i d o t o h p 12 g fat (cid:5) 9 kcal/g (cid:2) 108 kcal 108 kcal (cid:7) 140 kcal (cid:2) 77% second, the percent kcalories from fat guideline applies to a day s total intake, not to an individual food. -of course, if every selection throughout the day exceeds 35 percent kcalories from fat, you can be certain that the day s total intake will, too. -whether a person s energy and fat allowance can afford a piece of lemon meringue pie depends on the other food and activity choices made that day. -in summary in foods, triglycerides: deliver fat-soluble vitamins, energy, and essential fatty acids contribute to the sensory appeal of foods and stimulate appetite although some fat in the diet is necessary, health authorities recommend a diet moderate in total fat and low in saturated fat, trans fat, and cholesterol. -they also recommend replacing saturated fats with monounsaturated and polyunsaturated fats, particularly omega-3 fatty acids from foods such as fish, not from supplements. -many selection and preparation strategies can help bring these goals within reach, and food labels help to identify foods consis- tent with these guidelines. -if people were to make only one change in their diets, they would be wise to limit their intakes of saturated fat. -sometimes these choices can be difficult, though, be- cause fats make foods taste delicious. -to maintain good health, must a person give up all high-fat foods forever never again to eat marbled steak, hollandaise sauce, or gooey chocolate cake? -not at all. -these foods bring pleasure to a meal and can be enjoyed as part of a healthy diet when eaten occasionally in small quantities; but they should not be everyday foods. -the key word for fat is moderation, not depriva- tion. -appreciate the energy and enjoyment that fat provides, but take care not to ex- ceed your needs. -168 chapter 5 www.thomsonedu.com/thomsonnow nutrition portfolio to maintain good health, eat enough, but not too much, fat and select the right kinds. -list the types and amounts of fats and oils you eat daily, making note of which ones are saturated, monounsaturated, or polyunsaturated and how your choices could include fewer saturated options. -list the types and amounts of milk products, meats, fish, and poultry you eat daily, noting how your choices could include more low-fat options. -describe choices you can make in selecting and preparing foods to lower your intake of solid fats. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 5, then to nutrition on the net. -search for cholesterol and dietary fat at the u.s. gov- ernment health information site: www.healthfinder.gov search for fat at the international food information council site: www.ific.org find dietary strategies to prevent heart disease at the american heart association or national heart, lung, and blood institute: www.americanheart.org or nhlbi.nih.gov nutrition calculations for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 5, then to nutrition calculations. -these problems will give you practice in doing simple nutrition-related calculations (see p. 171 for answers). -show your calculations for each problem. -1. be aware of the fats in milks. -following are four categories of milk. -2. judge foods fat contents by their labels. -a. a food label says that one serving of the food contains 6.5 grams fat. -what would the % daily value for fat be? -what does the daily value you just calculated mean? -b. how many kcalories from fat does a serving contain? -wt (g) fat (g) prot (g) carb (g) (round off to the nearest whole number.) -milk a (1 c) milk b (1 c) milk c (1 c) milk d (1 c) 244 244 244 244 8 5 3 0 8 8 8 8 12 12 12 12 a. based on weight, what percentage of each milk is fat (round off to a whole number)? -b. how much energy from fat will a person receive from drinking 1 cup of each milk? -c. how much total energy will the person receive from 1 cup of each milk? -d. what percentage of the energy in each milk comes from fat? -e. in the grocery store, how is each milk labeled? -c. if a serving of the food contains 200 kcalories, what percentage of the energy is from fat? -this example should show you how easy it is to evaluate foods fat contents by reading labels and to see the difference between the % daily value and the percentage of kcalories from fat. -3. now consider a piece of carrot cake. -remember that the daily value suggests 65 grams of fat as acceptable within a 2000-kcalorie diet. -a serving of carrot cake provides 30 grams of fat. -what percentage of the daily value is that? -what does this mean? -the lipids: triglycerides, phospholipids, and sterols 169 study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review this chapter. -you will find the answers in the discussions on the pages provided. -1. name three classes of lipids found in the body and in foods. -what are some of their functions in the body? -what features do fats bring to foods? -(pp. -139, 145, 147, 153 155, 161) 2. what features distinguish fatty acids from each other? -(pp. -139 142) 3. what does the term omega mean with respect to fatty acids? -describe the roles of the omega fatty acids in dis- ease prevention. -(pp. -141 142, 158 159) 4. what are the differences between saturated, unsaturated, monounsaturated, and polyunsaturated fatty acids? -describe the structure of a triglyceride. -(pp. -140 143) 5. what does hydrogenation do to fats? -what are trans- fatty acids, and how do they influence heart disease? -(pp. -143 144, 157) 6. how do phospholipids differ from triglycerides in struc- ture? -how does cholesterol differ? -how do these differ- ences in structure affect function? -(pp. -145 147) 7. what roles do phospholipids perform in the body? -what roles does cholesterol play in the body? -(pp. -145 147) 8. trace the steps in fat digestion, absorption, and trans- port. -describe the routes cholesterol takes in the body. -(pp. -147 153) 9. what do lipoproteins do? -what are the differences among the chylomicrons, vldl, ldl, and hdl? -(pp. -150 153) 2. a triglyceride consists of: a. three glycerols attached to a lipid. -b. three fatty acids attached to a glucose. -c. three fatty acids attached to a glycerol. -d. three phospholipids attached to a cholesterol. -3. the difference between cis- and trans-fatty acids is: a. the number of double bonds. -b. the length of their carbon chains. -c. the location of the first double bond. -d. the configuration around the double bond. -4. which of the following is not true? -lecithin is: a. an emulsifier. -b. a phospholipid. -c. an essential nutrient. -d. a constituent of cell membranes. -5. chylomicrons are produced in the: a. liver. -b. pancreas. -c. gallbladder. -d. small intestine. -6. transport vehicles for lipids are called: a. micelles. -b. lipoproteins. -c. blood vessels. -d. monoglycerides. -7. the lipoprotein most associated with a high risk of heart disease is: a. chd. -b. hdl. -c. ldl. -d. lpl. -10. which of the fatty acids are essential? -name their chief 8. which of the following is not true? -fats: dietary sources. -(pp. -154 155) 11. how does excessive fat intake influence health? -what factors influence ldl, hdl, and total blood cholesterol? -(pp. -156 160) 12. what are the dietary recommendations regarding fat and cholesterol intake? -list ways to reduce intake. -(pp. -160 165) 13. what is the daily value for fat (for a 2000-kcalorie diet)? -what does this number represent? -(pp. -165 167) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 171. -1. saturated fatty acids: a. are always 18 carbons long. -b. have at least one double bond. -c. are fully loaded with hydrogens. -d. are always liquid at room temperature. -a. contain glucose. -b. provide energy. -c. protect against organ shock. -d. carry vitamins a, d, e, and k. 9. the essential fatty acids include: a. stearic acid and oleic acid. -b. oleic acid and linoleic acid. -c. palmitic acid and linolenic acid. -d. linoleic acid and linolenic acid. -10. a person consuming 2200 kcalories a day who wants to meet health recommendations should limit daily fat intake to: a. -20 to 35 grams. -b. -50 to 85 grams. -c. 75 to 100 grams. -d. 90 to 130 grams. -170 chapter 5 references 1. m. a. zulet and coauthors, inflammation and conjugated linoleic acid: mechanisms of action and implications for human health, journal of physiology and biochemistry 61 (2005): 483-494; m. a. belury, dietary conju- gated linoleic acid in health: physiological effects and mechanisms of action, annual review of nutrition 22 (2002): 505-531. -2. k. a. varady and coauthors, plant sterols and endurance training combine to favor- ably alter plasma lipid profiles in previously sedentary 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in subjects with cardiovascular disease in australia and new zealand: analysis of the long-term intervention with pravastatin in ischaemic disease trial, american journal of clinical nutrition 81 (2005): 1322-1329. -10. d. mozaffarian and coauthors, trans fatty acids and cardiovascular disease, new eng- land journal of medicine 354 (2006): 1601-1613. -11. j. dyerberg and coauthors, effects of trans- and n-3 unsaturated fatty acids on cardio- vascular risk markers in healthy males: an 8 weeks dietary intervention study, european journal of clinical nutrition 58 (2004): 1062- 1070; p. m. clifton, j. b. keogh, and m. noakes, trans fatty acids in adipose tissue and the food supply are associated with myocardial infarction, journal of nutrition 134 (2004): 874-879; n. m. deroos, e. g. schouten, and m. b. katan, trans fatty acids, hdl-cholesterol, and cardiovascular disease: effects of dietary changes on vascular reac- tivity, european journal of medical research 8 (2003): 355-357. -12. d. mozaffarian and coauthors, trans fatty acids and systemic inflammation in heart failure, american journal of clinical nutrition 80 (2004): 1521-1525; d. j. baer and coau- thors, dietary fatty acids affect plasma markers of inflammation in healthy men fed controlled diets: a randomized crossover study, american journal of clinical nutrition 79 (2004): 969-973; d. mozaffarian and coauthors, dietary intake of trans fatty acids and systemic inflammation in women, american journal of clinical nutrition 79 (2004): 606-612; g. a. bray and coauthors, the influence of different fats and fatty acids on obesity, insulin resistance and inflammation, journal of nutrition 132 (2002): 2488-2491. -13. federal register 68, july 11, 2003, p. 41444. -14. expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel iii), third report of the national cholesterol education program (ncep), nih publication no. -02- 5215 (bethesda, md. -: national heart, lung, and blood institute, 2002), p. v-10. -15. a. h. stark and z. madar, olive oil as a functional food: epidemiology and nutri- tional approaches, nutrition reviews 60 (2002): 170-176. -16. p. m. kris-etherton, k. d. hecker, and a. e. binkoski, polyunsaturated fatty acids and cardiovascular health, nutrition reviews 62 (2004): 414-426. -17. j. l. breslow, n-3 fatty acids and cardiovas- cular disease, american journal of clinical nutrition 83 (2006): 1477s-1482s; f. b. hu and coauthors, fish and omega-3 fatty acid intake and risk of coronary heart disease in women, journal of the american medical association 287 (2002): 1815-1821; c. m. albert and coauthors, blood levels of long- chain n-3 fatty acids and the risk of sudden death, new england journal of medicine 346 (2002): 1113-1118. -18. breslow, 2006; p. j. h. jones and v. w. y. lau, effect of n-3 polyunsaturated fatty acids on risk reduction of sudden death, nutrition reviews 60 (2002): 407-413. -19. m. c. nesheim and a. l. yaktine, eds., seafood, seafood choices: balancing benefits and risks (national academies press, wash- ington, d. c.: 2007), p. 12; c. w. levenson and d. m. axelrad, too much of a good thing? -update on fish consumption and murcury exposure, nutrition reviews 64 (2006): 139-145; e. guallar and coauthors, mercury, fish oils, and the risk of myocar- dial infarction, new england journal of medi- cine 347 (2002): 1747-1754. -20. v. wijendran and k. c. hayes, dietary n-6 and n-3 fatty acid balance and cardiovascu- lar health, annual review of nutrition 24 (2004): 597-615. -21. aha scientific statement: diet and lifestyle recommendations revision 2006, circulation 114 (2006): 82-96 22. k. he and coauthors, fish consumption and risk of stroke in men, journal of the american medical association 288 (2002): 3130-3136. -23. l. cordain and coauthors, fatty acid analy- sis of wild ruminant tissues: evolutionary implications for reducing diet-related chronic disease, european journal of clinical nutrition 56 (2002): 181-191. -24. s. bechoua and coauthors, influence of very low dietary intake of marine oil on some functional aspects of immune cells in healthy elderly people, british journal of nutrition 89 (2003): 523-532. -25. m. h. raitt and coauthors, fish oil supple- mentation and risk of ventricular tachycar- dia and ventricular fibrillation in patients with implantable defibrillators: a random- ized control study, journal of the american medical association 293 (2005): 2884-2891; p. m. kris-etherton and coauthors, aha scien- tific statement: fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease, circulation 106 (2002): 2747-2757. -26. c. b. stephensen, fish oil and inflammatory disease: is asthma the next target for n-3 fatty acid supplements? -nutrition reviews 62 (2004): 486-489. -27. g. l. khor, dietary fat quality: a nutritional epidemiologist s view, asia pacific journal of clinical nutrition 13 (2004): s22; r. stoeckli and u. keller, nutritional fats and the risk of type 2 diabetes and cancer, physiology and behavior 83 (2004): 611-615. -28. m. d. holmes and w. c. willett, does diet affect breast cancer risk? -breast cancer re- search 6 (2004): 170-178. -29. l. k. dennis and coauthors, problems with the assessment of dietary fat in prostate cancer studies, american journal of epidemiol- ogy 160 (2004): 436-444. -30. p. w. parodi, dairy product consumption and the risk of breast cancer, journal of the american college of nutrition 24 (2005): 556s- 568s; j. zhang and h. kesteloot, milk con- sumption in relation to incidence of prostate, breast, colon, and rectal cancers: is there an independent effect? -nutrition and cancer 53 (2005): 65-72. -31. c. h. maclean and coauthors, effects of omega-3 fatty acids on cancer risk-a system- atic review, journal of the american medical association 295 (2006): 403-415; w. e. hard- man, (n-3) fatty acids and cancer therapy, journal of nutrition 134 (2004): 3427s-3430s; m. f. leitzmann and coauthors, dietary intake of n-3 and n-6 fatty acids and the risk of prostate cancer, american journal of clinical nutrition 80 (2004): 204-216; s. c. larsson and coauthors, dietary long-chain n-3 fatty acids for the prevention of cancer: a review of potential mechanisms, american journal of clinical nutrition 79 (2004): 935-945. -32. committee on dietary reference intakes, dietary reference intakes for energy, carbohy- drate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (washington, d.c.: national academies press, 2002/2005). -33. committee on dietary reference intakes, 2002/2005. -the lipids: triglycerides, phospholipids, and sterols 171 34. committee on dietary reference intakes, 2002/2005. -35. national center for health statistics, chart- book on trends in the health of americans, 2005, www.cdc.gov/nchs, site visited on january 18, 2006; committee on dietary reference intakes, 2002/2005. -36. position of the american dietetic associa- tion, dietitians of canada, and the ameri- can college of sports medicine: nutrition and athletic performance, journal of the american dietetic association 100 (2000): 1543-1556. -37. s. tonstad, k. smerud, and l. h ie, a com- parison of the effects of 2 doses of soy protein or casein on serum lipids, serum lipoproteins, and plasma total homocys- teine in hypercholesterolemic subjects, american journal of clinical nutrition 76 (2002): 78-84. -38. b. m. davy and coauthors, high-fiber oat cereal compared with wheat cereal con- sumption favorably alters ldl-cholesterol subclass and particle numbers in middle- aged and older men, american journal of clinical nutrition 76 (2002): 351-358; d. j. a. jenkins and coauthors, soluble fiber intake at a dose approved by the u.s. food and drug administration for a claim of health benefits: serum lipid risk factors for cardio- vascular disease assessed in a randomized controlled crossover trial, american journal of clinical nutrition 75 (2002): 834-839. -39. c. s. patch, l. c. tapsell, and p. g. williams, plant sterol/stanol prescription is an effec- tive treatment strategy for managing hyper- cholesterolemia in outpatient clinical practice, journal of the american dietetic association 105 (2005): 46-52. -40. position of the american dietetic associa- tion: fat replacers, journal of the american dietetic association 105 (2005): 266-275. answers nutrition calculations 1. a. milk a: 8 g fat (cid:7) 244 g total (cid:2) 0.03; 0.03 (cid:5) 100 = 3% milk b: 5 g fat (cid:7) 244 g total (cid:2) 0.02; 0.02 (cid:5) 100 = 2% milk c: 3 g fat (cid:7) 244 g total (cid:2) 0.01; 0.01 (cid:5) 100 = 1% milk d: 0 g fat (cid:7) 244 g total (cid:2) 0.00; 0.00 (cid:5) 100 = 0% b. milk a: 8 g fat (cid:5) 9 kcal/g (cid:2) 72 kcal from fat milk b: 5 g fat (cid:5) 9 kcal/g (cid:2) 45 kcal from fat milk c: 3 g fat (cid:5) 9 kcal/g (cid:2) 27 kcal from fat milk d: 0 g fat (cid:5) 9 kcal/g (cid:2) 0 kcal from fat c. milk a: (8 g fat (cid:5) 9 kcal/g) (cid:11) (8 g prot (cid:5) 4 kcal/g) (cid:11) (12 g carb (cid:5) 4 kcal/g) (cid:2) 152 kcal milk b: (5 g fat (cid:5) 9 kcal/g) (cid:11) (8 g prot (cid:5) 4 kcal/g) (cid:11) (12 g carb (cid:5) 4 kcal/g) (cid:2) 125 kcal milk c: (3 g fat (cid:5) 9 kcal/g) (cid:11) (8 g prot (cid:5) 4 kcal/g) (cid:11) (12 g carb (cid:5) 4 kcal/g) (cid:2) 107 kcal milk d: (0 g fat (cid:5) 9 kcal/g) (cid:11) (8 g prot (cid:5) 4 kcal/g) (cid:11) (12 g carb (cid:5) 4 kcal/g) (cid:2) 80 kcal d. milk a: 72 kcal from fat (cid:7) 152 total kcal (cid:2) 0.47; 0.47 (cid:5) 100 (cid:2) 47% milk b: 45 kcal from fat (cid:7) 125 total kcal (cid:2) 0.36; 0.36 (cid:5) 100 (cid:2) 36% milk c: 27 kcal from fat (cid:7) 107 total kcal (cid:2) 0.25; 0.25 (cid:5) 100 (cid:2) 25% milk d: 0 kcal from fat (cid:7) 80 total kcal (cid:2) 0.00; 0.00 (cid:5) 100 (cid:2) 0% e. milk a: whole milk b: reduced-fat, 2%, or less-fat milk c: low-fat or 1% milk d: fat-free, nonfat, skim, zero-fat, or no-fat 2. a. -6.5 g (cid:7) 65 g (cid:2) 0.1; 0.1 (cid:5) 100 (cid:2) 10%; a daily value of 10% means that one serving of this food contributes about 1 10 of the day s fat allotment b. -6.5 g (cid:5) 9 kcal/g (cid:2) 58.5, rounded to 59 kcal from fat c. (59 kcal from fat (cid:7) 200 kcal) (cid:5) 100 (cid:2) 30% kcalories from fat 3. -(30 g fat (cid:7) 65 g fat) (cid:5) 100 (cid:2) 46% of the daily value for fat; this means that almost half of the day s fat allotment would be used in this one dessert study questions (multiple choice) 1. c 9. d 2. c 10. b 3. d 4. c 5. d 6. b 7. c 8. a highlight 5 high-fat foods friend or foe? -eat less fat. -eat more fatty fish. -give up butter. -use margarine. -give up margarine. -use olive oil. -steer clear of saturated. -seek out omega- 3. stay away from trans. -stick with mono- and polyunsaturated. -keep fat intake moder- ate. -today s fat messages seem to be forever multiplying and changing. -no wonder peo- ple feel confused about dietary fat. -the con- fusion stems in part from the complexities of fat and in part from the nature of recommendations. -as chapter 5 explained, dietary fat refers to several kinds of fats. -some fats support health whereas others damage it, and foods typically provide a mixture of fats in varying proportions. -researchers have spent decades sorting through the relationships among the various kinds of fat and their roles in supporting or harming health. -translating these research findings into dietary recommendations is challenging. -too little information can mislead consumers, but too much de- tail can overwhelm them. -as research findings accumulate, rec- ommendations slowly evolve and become more refined. -fortunately, that s where we are with fat recommendations to- day refining them from the general to the specific. -though they may seem to be forever multiplying and changing, in fact, they are becoming more meaningful. -this highlight begins with a look at the dietary guidelines for fat intake. -it continues by identifying which foods provide which fats and presenting the mediterranean diet, an example of a food plan that embraces the heart-healthy fats. -it closes with strategies to help consumers choose the right amounts of the right kinds of fats for a healthy diet. -guidelines for fat intake dietary recommendations for fat have changed in recent years, shifting the emphasis from lowering total fat, in general, to limit- ing saturated and trans fat, specifically. -for decades, health ex- perts advised limiting intakes of total fat to 30 percent or less of energy intake. -they recognized that saturated fats and trans fats are the fats that raise blood cholesterol but reasoned that by lim- iting total fat intake, saturated and trans fat intake would decline as well. -people were simply advised to cut back on all fat and thereby they would cut back on saturated and trans fat. -such ad- vice may have oversimplified the message and unnecessarily re- stricted total fat. -low-fat diets have a place in treatment plans for people with elevated blood lipids or heart disease, but some researchers ques- tion the wisdom of such diets for healthy people as a means of controlling weight and preventing diseases. -several problems ac- 172 s e g a m i r e t i p u j / x i p d o o f / y r r e v l a s company low-fat diets. -for one, many people find low-fat diets difficult to maintain over time. -for another, low-fat diets are not neces- sarily low-kcalorie diets. -if energy intake ex- ceeds energy needs, weight gain follows, and obesity brings a host of health problems, in- cluding heart disease. -for still another, diets extremely low in fat may exclude fatty fish, nuts, seeds, and vegetable oils all valuable sources of many es- sential fatty acids, phytochemicals, vitamins, and minerals. -im- portantly, the fats from these sources protect against heart disease, as later sections of this highlight explain. -p i l i h p instead of urging people to cut back on all fats, current recom- mendations suggest carefully replacing the bad saturated fats with the good unsaturated fats and enjoying them in modera- tion.1 the goal is to create a diet moderate in kcalories that pro- vides enough of the fats that support good health, but not too much of those that harm health. -(turn to pp. -156 160 for a re- view of the health consequences of each type of fat.) -with these findings and goals in mind, the dri committee sug- gests a healthy range of 20 to 35 percent of energy intake from fat. -this range appears to be compatible with low rates of heart disease, diabetes, obesity, and cancer.2 heart-healthy recommen- dations suggest that within this range, consumers should try to minimize their intakes of saturated fat, trans fat, and cholesterol and use monounsaturated and polyunsaturated fats instead.3 asking consumers to limit their total fat intake was less than perfect advice, but it was straightforward find the fat and cut back. -asking consumers to keep their intakes of saturated fats, trans fats, and cholesterol low and to use monounsaturated and polyunsaturated fats instead may be more on target with heart health, but it also makes diet planning more complicated. -to make appropriate selections, consumers must first learn which foods contain which fats. -high-fat foods and heart health avocados, bacon, walnuts, potato chips, and mackerel are all high-fat foods, yet some of these foods have detrimental effects on heart health when consumed in excess, whereas others seem neutral or even beneficial. -this section presents some of the accu- mulating evidence that helped to distinguish which high-fat foods belong in a healthy diet and which ones need to be kept to a minimum. -as you will see, a little more fat in the diet may be compatible with heart health, but only if the great majority of it is the unsaturated kind. -cook with olive oil as it turns out, the traditional diets of greece and other countries in the mediterranean region offer an excellent example of eating patterns that use good fats liberally. -often, these diets are rich in olives and their oil. -a classic study of the world s people, the seven countries study, found that death rates from heart disease were strongly associated with diets high in saturated fats but only weakly linked with total fat.4 in fact, the two countries with the highest fat intakes, finland and the greek island of crete, had the highest (finland) and lowest (crete) rates of heart disease deaths. -in both countries, the people consumed 40 percent or more of their kcalories from fat. -clearly, a high-fat diet was not the pri- mary problem, so researchers refocused their attention on the type of fat. -they began to notice the benefits of olive oil. -a diet that uses olive oil instead of other cooking fats, especially butter, stick margarine, and meat fats, may offer numerous health benefits.5 olive oil and other oils rich in mono- unsaturated fatty acids help to protect against heart disease by: lowering total and ldl cholesterol and not lowering hdl cholesterol or raising triglycerides6 lowering ldl cholesterol susceptibility to oxidation7 lowering blood-clotting factors8 providing phytochemicals that act as antioxidants (see high- light 11)9 lowering blood pressure10 when compared with other fats, olive oil seems to be a wise choice, but controlled clinical trials are too scarce to support popu- lation-wide recommendations to switch to a high-fat diet rich in olive oil. -importantly, olive oil is not a magic potion; drizzling it on foods does not make them healthier. -like other fats, olive oil delivers 9 kcalories per gram, which can contribute to weight gain in people who fail to balance their energy intake with their energy output. -its role in a healthy diet is to replace the saturated fats. -other vegetable oils, such as canola or safflower oil, are also generally low in satu- rated fats and high in unsaturated fats. -for this reason, heart-healthy diets use these unsaturated vegetable oils as substitutes for the more saturated fats of butter, hydrogenated stick margarine, lard, or shortening. -(remember that the tropical oils coconut, palm, and palm kernel are too saturated to be included with the heart- healthy vegetable oils.) -nibble on nuts tree nuts and peanuts are traditionally excluded from low-fat di- ets, and for good reasons. -nuts provide up to 80 percent of their kcalories from fat, and a quarter cup (about an ounce) of mixed nuts provides over 200 kcalories. -in a recent review of the liter- ature, however, researchers found that people who ate a one- ounce serving of nuts on five or more days a week had a reduced risk of heart disease compared with people who con- sumed no nuts.11 a smaller positive association was noted for high-fat foods friend or foe? -173 o i g g u r r a f w e h t t a m olives and their oil may benefit heart health. -any amount greater than one serving of nuts a week. -the nuts in this study were those commonly eaten in the united states: almonds, brazil nuts, cashews, hazelnuts, macadamia nuts, pecans, pistachios, walnuts, and even peanuts. -on average, these nuts contain mostly monounsaturated fat (59 percent), some polyunsaturated fat (27 percent), and little saturated fat (14 percent). -research has shown a benefit from walnuts and almonds in particular. -in study after study, walnuts, when substituted for other fats in the diet, produce favorable effects on blood lipids even in people with elevated total and ldl cholesterol.12 results are similar for almonds. -in one study, researchers gave men and women one of three kinds of snacks, all of equal kcalories: whole- wheat muffins, almonds (about 21/2 ounces), or half muffins and half almonds.13 at the end of a month, people receiving the full almond snack had the greatest drop in blood ldl cholesterol; those eating the half almond snack had a lesser, but still signifi- cant, drop in blood lipids; and those eating the muffin only snack had no change. -studies on peanuts, macadamia nuts, pecans, and pistachios follow suit, indicating that including nuts may be a wise strategy against heart disease. -nuts may protect against heart disease be- cause they provide: monounsaturated and polyunsaturated fats in abundance, but few saturated fats fiber, vegetable protein, and other valuable nutrients, in- cluding the antioxidant vitamin e (see highlight 11) phytochemicals that act as antioxidants (see highlight 13) before advising consumers to include nuts in their diets, a cau- tion is in order. -as mentioned, most of the energy nuts provide comes from fats. -consequently, they deliver many kcalories per bite. -in studies examining the effects of nuts on heart disease, re- searchers carefully adjust diets to make room for the nuts without 174 highlight 5 for heart health, snack on a few nuts instead of potato chips. -because nuts are energy dense (high in kcalories per ounce), it is especially important to keep portion size in mind when eating them. -increasing the total kcalories that is, they use nuts instead of, not in addition to, other foods (such as meats, potato chips, oils, mar- garine, and butter). -consumers who do not make similar replace- ments could end up gaining weight if they simply add nuts on top of their regular diets. -weight gain, in turn, elevates blood lipids and raises the risks of heart disease. -feast on fish research into the health benefits of the long-chain omega-3 polyunsaturated fatty acids began with a simple observation: the native peoples of alaska, northern canada, and greenland, who eat a diet rich in omega-3 fatty acids, notably epa and dha, have a remarkably low rate of heart disease even though their diets are relatively high in fat.14 these omega-3 fatty acids help to protect against heart disease by:15 reducing blood triglycerides preventing blood clots protecting against irregular heartbeats lowering blood pressure defending against inflammation serving as precursors to eicosanoids for people with hypertension or atherosclerosis, these actions can be life saving. -research studies have provided strong evidence that increas- ing omega-3 fatty acids in the diet supports heart health and low- ers the rate of deaths from heart disease.16 for this reason, the american heart association recommends including fish in a heart-healthy diet. -people who eat some fish each week can lower their risks of heart attack and stroke. -table 5-2 on p. 159 lists fish that provide at least 1 gram of omega-3 fatty acids per serving. -fish is the best source of epa and dha in the diet, but it is also a major source of mercury, an environmental contaminant. -most fish contain at least trace amounts of mercury, but tilefish (also known as o i g g u r r a f w e h t t a m golden snapper or golden bass), swordfish, king mackerel, marlin, and shark have especially high levels. -for this reason, the fda ad- vises pregnant and lactating women, women of childbearing age who may become pregnant, and young children to avoid: tilefish (also called golden snapper or golden bass), sword- fish, king mackeral, marlin, and shark and to limit average weekly consumption of: a variety of fish and shellfish to 12 ounces (cooked or canned) white (albacore) tuna to 6 ounces (cooked or canned) commonly eaten seafood relatively low in mercury include shrimp, catfish, pollock, salmon, and canned light tuna. -in addition to the direct toxic effects of mercury, some (but not all) research suggests that mercury may diminish the health benefits of omega-3 fatty acids.17 such findings serve as a re- minder that our health depends on the health of our planet. -the protective effect of fish in the diet is available, provided that the fish and their surrounding waters are not heavily contaminated. -(chapter 19 discusses the adverse consequences of mercury, and chapter 20 presents the relationships between diet and the envi- ronment in more detail.) -in an effort to limit exposure to pollutants, some consumers choose farm-raised fish. -compared with fish caught in the wild, farm-raised fish tend to be lower in mercury, but they are also lower in omega-3 fatty acids. -when selecting fish, keep the diet strategies of variety and moderation in mind. -varying choices and eating moderate amounts helps to limit the intake of contami- nants such as mercury. -m o c . -k c o t s m o c . -w w w fish is a good source of the omega-3 fatty acids. -high-fat foods and heart disease the number one dietary determinant of ldl cholesterol is satu- rated fat. -figure h5-1 shows that each 1 percent increase in en- ergy from saturated fatty acids in the diet may produce a 2 percent jump in heart disease risk by elevating blood ldl choles- terol. -conversely, reducing saturated fat intake by 1 percent can be expected to produce a 2 percent drop in heart disease risk by the same mechanism. -even a 2 percent drop in ldl represents a significant improvement for the health of the heart.18 like satu- rated fats, trans fats also raise heart disease risk by elevating ldl cholesterol. -a heart-healthy diet limits foods rich in these two types of fat. -limit fatty meats, whole-milk products, and tropical oils the major sources of saturated fats in the u.s. diet are fatty meats, whole milk products, tropical oils, and products made from any of these foods. -to limit saturated fat intake, consumers must choose carefully among these high-fat foods. -over a third of the fat in most meats is saturated. -similarly, over half of the fat is saturated in whole milk and other high-fat dairy products, such as cheese, butter, cream, half-and-half, cream cheese, sour cream, and ice cream. -the tropical oils of palm, palm kernel, and co- conut, which are rarely used by consumers in the kitchen, are used heavily by food manufacturers, and are commonly found in many commercially prepared foods. -when choosing meats, milk products, and commercially pre- pared foods, look for those lowest in saturated fat. -labels provide a useful guide for comparing products in this regard, and appen- dix h lists the saturated fat in several thousand foods. -high-fat foods friend or foe? -175 even with careful selections, a nutritionally adequate diet will provide some saturated fat. -zero saturated fat is not possible even when experts design menus with the mission to keep saturated fat as low as possible.19 because most saturated fats come from ani- mal foods, vegetarian diets can, and usually do, deliver fewer sat- urated fats than mixed diets. -limit hydrogenated foods chapter 5 explained that solid shortening and margarine are made from vegetable oil that has been hardened through hydro- genation. -this process both saturates some of the unsaturated fatty acids and introduces trans-fatty acids. -many convenience foods contain trans fats, including: fried foods such as french fries, chicken, and other com- mercially fried foods commercial baked goods such as cookies, doughnuts, pas- tries, breads, and crackers snack foods such as chips imitation cheeses to keep trans fat intake low, use these foods sparingly as an occa- sional taste treat. -table h5-1 (p. 176) summarizes which foods provide which fats. -substituting unsaturated fats for saturated fats at each meal and snack can help protect against heart disease. -figure h5-2 (p. 176) compares two meals and shows how such substitutions can lower saturated fat and raise unsaturated fat even when total fat and kcalories remain unchanged. -the mediterranean diet the links between good health and traditional mediterranean di- ets of the mid-1900s were introduced earlier with regard to olive figure h5-1 potential relationships among dietary saturated fatty acids, ldl cholesterol, and heart disease risk 1% increase in dietary saturated fatty acidsa 1% decrease in dietary saturated fatty acidsa 2% increase in ldl cholesterolb 2% increase in heart disease riskc 2% decrease in ldl cholesterolb 2% decrease in heart disease riskc apercentage of change in total dietary energy from saturated fatty acids. -bpercentage of change in blood ldl cholesterol. -cpercentage of change in an individual s risk of heart disease; the percentage of change in risk may increase when blood lipid changes are sustained over time. -source: third report of the national cholesterol education program (ncep) expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel iii), nih publication no. -02-5215 (bethesda, md. -: national heart, lung, and blood institute, 2002), p. v-8 and ii-4. -176 highlight 5 table h5-1 major sources of various fatty acids healthful fatty acids monounsaturated avocado omega-6 polyunsaturated omega-3 polyunsaturated margarine (nonyhydrogenated) fatty fish (herring, mackerel, salmon, tuna) oils (canola, olive, peanut, sesame) oils (corn, cottonseed, safflower, soybean) flaxseed nuts (almonds, cashews, filberts, hazelnuts, macadamia nuts, peanuts, pecans, pistachios) olives peanut butter seeds (sesame) harmful fatty acids saturated bacon butter chocolate coconut cream cheese cream, half-and-half lard meat milk and milk products (whole) oils (coconut, palm, palm kernel) shortening sour cream note: keep in mind that foods contain a mixture of fatty acids. -nuts (pine nuts, walnuts) nuts (walnuts) mayonnaise salad dressing seeds (pumpkin, sunflower) trans fried foods (hydrogenated shortening) margarine (hydrogenated or partially hydrogenated) nondairy creamers many fast foods shortening commercial baked goods (including doughnuts, cakes, cookies) many snack foods (including microwave popcorn, chips, crackers) figure h5-2 two meals compared: replacing saturated fat with unsaturated fat examples of ways to replace saturated fats with unsaturated fats include saut ing vegetables in olive oil instead of butter, garnishing salads with avocado and sunflower seeds instead of bacon and blue cheese, and eating salmon instead of steak. -each of these meals provides roughly the same number of kcalories and grams of fat, but the one on the left has almost four times as much saturated fat and only half as many omega-3 fatty acids. -to lower saturated fat and raise monounsaturated and polyunsaturated fats... ) h t o b ( o i g g u r r a f w e h t t a m saturated fats meal 1 c fresh broccoli topped with 1 t butter 1 c mixed baby greens salad with 2 strips bacon (crumbled) 1 oz blue cheese crumbles unsaturated fat saturated fat unsaturated fats meal 1 c fresh broccoli saut ed in 1 t olive oil 1 c mixed baby greens salad with avocado 1 2 2 t sunflower seeds 4 oz grilled steak total fat 4 oz grilled salmon energy = 600 kcal energy = 600 kcal 0 1010 30 20 grams 40 50 oil. -for people who eat these diets, the incidence of heart disease, some cancers, and other chronic diseases is low, and life ex- pectancy is high.20 although each of the many countries that border the mediter- ranean sea has its own culture, traditions, and dietary habits, their similarities are much greater than the use of olive oil alone. -in fact, according to a recent study, no one factor alone can be credited with reducing disease risks the association holds true only when the overall diet pattern is present.21 apparently, each of the foods contributes small benefits that harmonize to produce either a substantial cumulative or a synergistic effect. -the mediterranean people focus their diets on crusty breads, whole grains, potatoes, and pastas; a variety of vegetables (including wild greens) and legumes; feta and mozzarella cheeses and yogurt; nuts; and fruits (especially grapes and figs). -they eat some fish, other seafood, poultry, a few eggs, and little meat. -along with olives and olive oil, their principal sources of fat are nuts and fish; they rarely use butter or encounter hydrogenated fats. -consequently, traditional mediterranean diets are: low in saturated fat very low in trans fat rich in unsaturated fat rich in complex carbohydrate and fiber rich in nutrients and phytochemicals that support good health people following the traditional mediterranean diet can re- ceive as much as 40 percent of a day s kcalories from fat, but their limited consumption of dairy products and meats provides less than 10 percent from saturated fats. -in addition, because the animals in the mediterranean region graze, the meat, dairy prod- ucts, and eggs are richer in omega-3 fatty acids than those from animals fed grain. -other foods typical of the mediterranean, such as wild plants and snails, provide omega-3 fatty acids as well. -all in all, the traditional mediterranean diet has gained a reputation for its health benefits as well as its delicious flavors, but beware of the typical mediterranean-style cuisine available in u.s. restaurants. -it has been adjusted to popular tastes, meaning that it is often much higher in saturated fats and meats and much lower in the potentially beneficial constituents than the traditional fare. -unfortunately, it appears that people in the mediterranean region who are replacing some of their tradi- tional dietary habits with those of the united states are losing the health benefits previously enjoyed.22 conclusion are some fats good, and others bad from the body s point of view? -the saturated and trans fats indeed seem mostly bad for the health of the heart. -aside from providing energy, which un- saturated fats can do equally well, saturated and trans fats bring no indispensable benefits to the body. -furthermore, no harm can high-fat foods friend or foe? -177 come from consuming diets low in them. -still, foods rich in these fats are often delicious, giving them a special place in the diet. -in contrast, the unsaturated fats are mostly good for the health of the heart when consumed in moderation. -to date, their one proven fault seems to be that they, like all fats, provide abundant energy to the body and so may promote obesity if they drive kcalorie intakes higher than energy needs.23 obesity, in turn, of- ten begets many body ills, as chapter 8 makes clear. -when judging foods by their fatty acids, keep in mind that the fat in foods is a mixture of good and bad, providing both sat- urated and unsaturated fatty acids. -even predominantly monoun- saturated olive oil delivers some saturated fat. -consequently, even when a person chooses foods with mostly unsaturated fats, satu- rated fat can still add up if total fat is high. -for this reason, fat must be kept below 35 percent of total kcalories if the diet is to be moderate in saturated fat. -even experts run into difficulty when attempting to create nutritious diets from a variety of foods that are low in saturated fats when kcalories from fat exceed 35 per- cent of the total.24 does this mean that you must forever go without favorite cheeses, ice cream cones, or a grilled steak? -the famous chef ju- lia child made this point about moderation: an imaginary shelf labeled indulgences is a good idea. -it contains the best butter, jumbo-size eggs, heavy cream, marbled steaks, sausages and p t s, hollandaise and butter sauces, french butter-cream fillings, gooey chocolate cakes, and all those lovely items that demand disciplined rationing. -thus, with these items high up and almost out of reach, we are ever conscious that they are not everyday foods. -they are for special occasions, and when that occa- sion comes we can enjoy every mouthful. -julia child, the way to cook, 1989 additionally, food manufacturers have come to the assistance of consumers who wish to avoid the health threats from saturated and trans fats. -some margarine makers no longer offer products containing trans fats, and many snack manufacturers have re- duced the saturated and trans fats in some products and now of- fer snack foods in 100-kcalorie packages. -other companies are following as consumers respond favorably. -adopting some of the mediterranean eating habits may serve those who enjoy a little more fat in the diet. -including vegetables, fruits, and legumes as part of a balanced daily diet is a good idea, as is replacing saturated fats such as butter, short- ening, and meat fat with unsaturated fats like olive oil and the oils from nuts and fish. -these foods provide vitamins, minerals, and phytochemicals all valuable in protecting the body s health. -the authors of this book do not stop there, however. -they urge you to reduce fats from convenience foods and fast foods; choose small portions of meats, fish, and poultry; and in- clude fresh foods from all the food groups each day. -take care to select portion sizes that will best meet your energy needs. -also, exercise daily. -178 highlight 5 references 1. third report of the national cholesterol educa- tion program (ncep) expert panel on detec- tion, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel iii), publication nih no. -02-5215 (bethesda, md. -: national heart, lung, and blood institute, 2002); committee on dietary reference intakes, dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (washington, d.c.: national academies press, 2002/2005). -2. committee on dietary reference intakes, 2002/2005, p. 769. -3. american heart association scientific state- ment: diet and lifestyle recommendations revision 2006, circulation 114 (2006): 82-96; third report of the national cholesterol educa- tion program (ncep) expert panel on detec- tion, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel iii), publication nih no. -02-5215 (bethesda, md. -: national heart, lung, and blood institute, 2002); committee on dietary reference intakes, dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (washington, d.c.: national academies press, 2002/2005). -4. a. keys, seven countries: a multivariate analysis of death and coronary heart disease (cambridge: harvard university press, 1980). -5. a. h. stark and z. madar, olive oil as a functional food: epidemiology and nutri- tional approaches, nutrition reviews 60 (2002): 170 176. -6. m. i. covas and coauthors, the effect of polyphenols in olive oil on heart disease risk factors, annals of internal medicine 145 (2006): 333-341. -7. f. visioli and coauthors, virgin olive oil study (volos): vasoprotective potential of extra virgin olive oil in mildly dislipidemic patients, european journal of nutrition 44 (2005): 121-127. -8. j. l pez-miranda, monounsaturated fat and cardiovascular risk, nutrition reviews 64 (2006): s2-s12. -9. f. visioli and c. galli, biological properties of olive oil phytochemicals, critical reviews in food science and nutrition 42 (2002): 209- 221; m. n. vissers and coauthors, olive oil phenols are absorbed in humans, journal of nutrition 132 (2002): 409-417. -10. b. m. rasmussen and coauthors, effects of dietary saturated, monounsaturated, and n- 3 fatty acids on blood pressure in healthy subjects, american journal of clinical nutri- tion 83 (2006): 221-226; t. psaltopoulou and coauthors, olive oil, the mediterranean diet, and arterial blood pressure: the greek european prospective investigation into cancer and nutrition (epic) study, american journal of clinical nutrition 80 (2004): 1012- 1018. -11. j. h. kelly and j. sabate, nuts and coronary heart disease: an epidemiological perspec- tive, british journal of nutrition 96 (2006): s61-s67. -12. e. b. feldman, the scientific evidence for a beneficial health relationship between walnuts and coronary heart disease, journal of nutrition 132 (2002): 1062s 1101s. -13. d. j. jenkins and coauthors, dose response of almonds on coronary heart disease risk factors: blood lipids, oxidized low-density lipoproteins, lipoprotein (a), homocysteine, and pulmonary nitric oxide: a randomized, controlled, crossover trial, circulation 106 (2002): 1327 1332. -14. e. dewailly and coauthors, cardiovascular disease risk factors and n-3 fatty acid status in the adult population of james bay cree, american journal of clinical nutrition 76 (2002): 85 92. -15. j. l. breslow, n-3 fatty acids and cardiovas- cular disease, american journal of clinical nutrition 83 (2006): 1477s-1482s; p. j. h. jones and v. w. y. lau, effect of n-3 polyun- saturated fatty acids on risk reduction of sudden death, nutrition reviews 60 (2002): 407 413. -16. breslow, 2006; f. b. hu and coauthors, fish and omega-3 fatty acid intake and risk of coronary heart disease in women, journal of the american medical association 287 (2002): 1815 1821. -17. e. guallar and coauthors, mercury, fish oils, and the risk of myocardial infarction, new england journal of medicine 347 (2002): 1747 1754; k. yoshizawa and coauthors, mercury and the risk of coronary heart disease in man, new england journal of medicine 347 (2002): 1755 1760. -18. third report of the national cholesterol educa- tion program (ncep) expert panel on detec- tion, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel iii), 2002, p.v-8. -19. committee on dietary reference intakes, 2002/2005, p. 835. -20.l. -serra-majem, b. roman, and r. estruch, scientific evidence of interventions using the mediterranean diet: a systematic review, nutrition reviews 64 (2006): s27 s47; c. pitsavos and coauthors, adherence to the mediterranean diet is associated with total antioxidant capacity in healthy adults: the attica study, american journal of clinical nutrition 82 (2005): 694 699; m. meydani, a mediterranean-style diet and metabolic syndrome, nutrition reviews 63 (2005): 312 314; d. b. panagiotakos and coauthors, can a mediterranean diet moderate the development and clinical progression of coronary heart disease? -a systematic review, medical science monitor 10 (2004): ra193 ra198; k. t. b. knoops and coau- thors, mediterranean diet, lifestyle factors, and 10-year mortality in elderly european men and women, journal of the american medical association 292 (2004): 1433 1439; k. esposito and coauthors, effect of a mediterranean-style diet on endothelial dysfunction and markers of vascular inflam- mation in the metabolic syndrome: a ran- domized study, journal of the american medical association 292 (2004): 1440 1446. -21. a. trichopoulou and coauthors, adherence to a mediterranean diet and survival in a greek population, new england journal of medicine 348 (2003): 2599 2608. -22. f. sofi and coauthors, dietary habits, lifestyle, and cardiovascular risk factors in a clinically healthy italian population: the florence diet is not mediterranean, euro- pean journal of clinical nutrition 59 (2005): 584 591. -23. committee on dietary reference intakes, 2002/2005, pp. -796-797. -24.committee on dietary reference intakes, 2002/2005, pp. -799-802. this page intentionally left blank russell wasserfall/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow figure 6.6: animated! -protein digestion in the gi tract figure 6.7: animated! -protein synthesis figure 6.10: animated! -an example of protein transport how to: practice problems nutrition portfolio journal nutrition in your life their versatility in the body is impressive. -they help your muscles to contract, your blood to clot, and your eyes to see. -they keep you alive and well by facilitating chemical reactions and defending against infections. -without them, your bones, skin, and hair would have no structure. -no wonder they were named proteins, meaning of prime importance. -does that mean proteins deserve top billing in your diet as well? -are the best sources of protein beef, beans, or broccoli? -learn which foods will supply you with nutrition calculations: practice problems enough, but not too much, high-quality protein. -protein: amino acids a few misconceptions surround the roles of protein in the body and the importance of protein in the diet. -for example, people who associate meat with protein and protein with strength may eat steak to build muscles. -their thinking is only partly correct, however. -protein is a vital structural and working substance in all cells not just muscle cells. -to build strength, muscles cells need physical activity and all the nutrients not just protein. -furthermore, protein is found in milk, eggs, legumes, and many grains and vegetables not just meat. -by overvaluing protein and overemphasiz- ing meat in the diet, a person may mistakenly crowd out other, equally im- portant nutrients and foods. -as this chapter describes the various roles of protein in the body and food sources in the diet, keep in mind that protein is one of many nutrients needed to maintain good health. -the chemist s view of proteins chemically, proteins contain the same atoms as carbohydrates and lipids carbon (c), hydrogen (h), and oxygen (o) but proteins also contain nitrogen (n) atoms. -these nitrogen atoms give the name amino (nitrogen containing) to the amino acids the links in the chains of proteins. -amino acids all amino acids have the same basic structure a central carbon (c) atom with a hydrogen atom (h), an amino group (nh2), and an acid group (cooh) attached to it. -however, carbon atoms need to form four bonds, so a fourth attachment is necessary. -this fourth site distinguishes each amino acid from the others. -attached to the carbon atom at the fourth bond is a distinct atom, or group of atoms, known as the side group or side chain (see figure 6-1). -unique side groups the side groups on amino acids vary from one amino acid to the next, making proteins more complex than either carbohydrates or lipids. -a polysaccharide (starch, for example) may be several thousand units long, but each unit is a glucose molecule just like all the others. -a protein, on the other hand, is c h a p t e r 6 chapter outline the chemist s view of proteins amino acids proteins digestion and absorption of protein protein digestion protein absorption proteins in the body protein syn- thesis roles of proteins a preview of protein metabolism protein in foods protein quality protein regulations for food labels health effects and recommended intakes of protein protein-energy malnutrition health effects of protein recommended intakes of protein protein and amino acid supplements highlight 6 nutritional genomics reminder: h forms 1 bond o forms 2 bonds n forms 3 bonds c forms 4 bonds proteins: compounds composed of carbon, hydrogen, oxygen, and nitrogen atoms, arranged into amino acids linked in a chain. -some amino acids also contain sulfur atoms. -amino (a-meen-oh) acids: building blocks of proteins. -each contains an amino group, an acid group, a hydrogen atom, and a distinctive side group, all attached to a central carbon atom. -amino = containing nitrogen 181 182 chapter 6 figure 6-1 amino acid structure table 6-1 amino acids side group varies o amino group h n c c o h h h acid group all amino acids have a carbon (known as the alpha-carbon), with an amino group (nh2), an acid group (cooh), a hydrogen (h), and a side group attached. -the side group is a unique chemical structure that differentiates one amino acid from another. -proteins are made up of about 20 common amino acids. -the first column lists the essential amino acids for human beings (those the body cannot make that must be provided in the diet). -the second column lists the nonessential amino acids. -in special cases, some nonessential amino acids may become conditionally essential (see the text). -in a newborn, for example, only five amino acids are truly nonessential; the other nonessential amino acids are conditionally essential until the metabolic pathways are developed enough to make those amino acids in adequate amounts. -essential amino acids nonessential amino acids histidine (hiss-tuh-deen) isoleucine (eye-so-loo-seen) leucine lysine (loo-seen) (lye-seen) alanine arginine (al-ah-neen) (arj-ih-neen) asparagine (ah-spar-ah-geen) aspartic acid (ah-spar-tic acid) methionine (meh-thigh-oh-neen) cysteine (sis-teh-een) phenylalanine (fen-il-al-ah-neen) glutamic acid (glu-tam-ic acid) threonine (three-oh-neen) glutamine (glu-tah-meen) tryptophan (trip-toe-fan, trip-toe-fane) valine (vay-leen) glycine proline serine (gly-seen) (pro-leen) (seer-een) tyrosine (tie-roe-seen) made up of about 20 different amino acids, each with a different side group. -table 6-1 lists the amino acids most common in proteins. -* the simplest amino acid, glycine, has a hydrogen atom as its side group. -a slightly more complex amino acid, alanine, has an extra carbon with three hydro- gen atoms. -other amino acids have more complex side groups (see figure 6-2 for examples). -thus, although all amino acids share a common structure, they differ in size, shape, electrical charge, and other characteristics because of differences in these side groups. -nonessential amino acids more than half of the amino acids are nonessential, meaning that the body can synthesize them for itself. -proteins in foods usually de- liver these amino acids, but it is not essential that they do so. -the body can make all nonessential amino acids, given nitrogen to form the amino group and frag- ments from carbohydrate or fat to form the rest of the structure. -*besides the 20 common amino acids, which can all be components of proteins, others do not occur in proteins, but can be found individually (for example, taurine and ornithine). -some amino acids occur in related forms (for example, proline can acquire an oh group to become hydroxyproline). -figure 6-2 examples of amino acids note that all amino acids have a common chemical structure but that each has a different side group. -appendix c presents the chemical structures of the 20 amino acids most common in proteins. -h o c o h ch h ch h ch h o o h o h n c c o h h n h h h c h c o h h n h c h c o h h n h c h o c o h nonessential amino acids: amino acids that the body can synthesize (see table 6-1). -glycine alanine aspartic acid phenylalanine essential amino acids there are nine amino acids that the human body either cannot make at all or cannot make in sufficient quantity to meet its needs. -these nine amino acids must be supplied by the diet; they are essential. -the first column in table 6-1 presents the essential amino acids. -conditionally essential amino acids sometimes a nonessential amino acid becomes essential under special circumstances. -for example, the body normally uses the essential amino acid phenylalanine to make tyrosine (a nonessential amino acid). -but if the diet fails to supply enough phenylalanine, or if the body can- not make the conversion for some reason (as happens in the inherited disease phenylketonuria), then tyrosine becomes a conditionally essential amino acid. -proteins cells link amino acids end-to-end in a variety of sequences to form thousands of dif- ferent proteins. -a peptide bond unites each amino acid to the next. -amino acid chains condensation reactions connect amino acids, just as they combine monosaccharides to form disaccharides and fatty acids with glycerol to form triglycerides. -two amino acids bonded together form a dipeptide (see figure 6-3). -by another such reaction, a third amino acid can be added to the chain to form a tripeptide. -as additional amino acids join the chain, a polypeptide is formed. -most proteins are a few dozen to several hundred amino acids long. -figure 6-4 (p. 184) provides an example insulin. -amino acid sequences if a person could walk along a carbohydrate mole- cule like starch, the first stepping stone would be a glucose. -the next stepping stone would also be a glucose, and it would be followed by a glucose, and yet another glucose. -but if a person were to walk along a polypeptide chain, each stepping stone would be one of 20 different amino acids. -the first stepping stone might be the amino acid methionine. -the second might be an alanine. -the third might be a glycine, and the fourth a tryptophan, and so on. -walking along another polypeptide path, a person might step on a phenylalanine, then a valine, and a glutamine. -in other words, amino acid sequences within pro- teins vary. -the amino acids can act somewhat like the letters in an alphabet. -if you had only the letter g, all you could write would be a string of gs: g g g g g g g. but with 20 different letters available, you can create poems, songs, and novels. -simi- larly, the 20 amino acids can be linked together in a variety of sequences even more than are possible for letters in a word or words in a sentence. -thus the variety of possible sequences for polypeptide chains is tremendous. -figure 6-3 condensation of two amino acids to form a dipeptide h h ch h ch h ch h ch h h n h c h o c o h h o c o h n h c h amino acid + amino acid h n h c h hoh water o c o h o c n h c h dipeptide an oh group from the acid end of one amino acid and an h atom from the amino group of another join to form a molecule of water. -a peptide bond (highlighted in red) forms between the two amino acids, creating a dipeptide. -protein: amino acids 183 some researchers refer to essential amino acids as indispensable and to nonessential amino acids as dispensable. -essential amino acids: amino acids that the body cannot synthesize in amounts sufficient to meet physiological needs (see table 6-1 on p. 182). -conditionally essential amino acid: an amino acid that is normally nonessential, but must be supplied by the diet in special circumstances when the need for it exceeds the body s ability to produce it. -peptide bond: a bond that connects the acid end of one amino acid with the amino end of another, forming a link in a protein chain. -dipeptide (dye-pep-tide): two amino acids bonded together. -di = two peptide = amino acid tripeptide: three amino acids bonded together. -tri = three polypeptide: many (ten or more) amino acids bonded together. -poly = many 184 chapter 6 figure 6-5 the structure of hemoglobin four highly folded polypeptide chains form the globular hemoglobin protein. -iron heme, the nonprotein portion of hemoglobin, holds iron. -the amino acid sequence determines the shape of the polypeptide chain. -figure 6-4 amino acid sequence of human insulin human insulin is a relatively small protein that consists of 51 amino acids in two short polypeptide chains. -(for amino acid abbreviations, see appendix c.) two bridges link the two chains. -a third bridge spans a section within the short chain. -known as disulfide bridges, these links always involve the amino acid cysteine (cys), whose side group contains sulfur (s). -cysteines connect to each other when bonds form between these side groups. -pro lys ala thr tyr phe phe gly arg glu gly cys tyr leu val s s leu ala glu val leu his ser gly cys leu his gln asn val phe s s gly ile val glu gln cys cys s s ala ser val asn cys tyr asn glu leu gln tyr leu ser cys protein shapes polypeptide chains twist into a variety of complex, tangled shapes, depending on their amino acid sequences. -the unique side group of each amino acid gives it characteristics that attract it to, or repel it from, the surrounding fluids and other amino acids. -some amino acid side groups carry electrical charges that are attracted to water molecules; they are hy- drophilic. -other side groups are neutral and are repelled by water; they are hy- drophobic. -as amino acids are strung together to make a polypeptide, the chain folds so that its charged hydrophilic side groups are on the outer surface near water; the neutral hydrophobic groups tuck themselves inside, away from water. -the intricate, coiled shape the polypeptide finally assumes gives it maximum stability. -protein functions the extraordinary and unique shapes of proteins enable them to perform their various tasks in the body. -some form hollow balls that can carry and store materials within them, and some, such as those of ten- dons, are more than ten times as long as they are wide, forming strong, rod- like structures. -some polypeptides are functioning proteins just as they are; others need to associate with other polypeptides to form larger working com- plexes. -some proteins require minerals to activate them. -one molecule of he- moglobin the large, globular protein molecule that, by the billions, packs the red blood cells and carries oxygen is made of four associated polypeptide chains, each holding the mineral iron (see figure 6-5). -protein denaturation when proteins are subjected to heat, acid, or other conditions that disturb their stability, they undergo denaturation that is, they uncoil and lose their shapes and, consequently, also lose their ability to function. -past a certain point, denaturation is irreversible. -familiar examples hemoglobin (he-moh-glo-bin): the globular protein of the red blood cells that carries oxygen from the lungs to the cells throughout the body. -hemo = blood globin = globular protein denaturation (dee-nay-chur-ay-shun): the change in a protein s shape and consequent loss of its function brought about by heat, agitation, acid, base, alcohol, heavy metals, or other agents. -in summary chemically speaking, proteins are more complex than carbohydrates or lipids, being made of some 20 different amino acids, 9 of which the body can- not make; they are essential. -each amino acid contains an amino group, an acid group, a hydrogen atom, and a distinctive side group, all attached to a central carbon atom. -cells link amino acids together in a series of condensa- tion reactions to create proteins. -the distinctive sequence of amino acids in each protein determines its unique shape and function. -of denaturation include the hardening of an egg when it is cooked, the curdling of milk when acid is added, and the stiffening of egg whites when they are whipped. -digestion and absorption of protein proteins in foods do not become body proteins directly. -instead, they supply the amino acids from which the body makes its own proteins. -when a person eats foods containing protein, enzymes break the long polypeptide strands into shorter strands, the short strands into tripeptides and dipeptides, and, finally, the tripeptides and dipeptides into amino acids. -protein digestion figure 6-6 (p. 186) illustrates the digestion of protein through the gi tract. -proteins are crushed and moistened in the mouth, but the real action begins in the stomach. -in the stomach the major event in the stomach is the partial breakdown (hydrol- ysis) of proteins. -hydrochloric acid uncoils (denatures) each protein s tangled strands so that digestive enzymes can attack the peptide bonds. -the hydrochloric acid also converts the inactive form of the enzyme pepsinogen to its active form, pepsin. -pepsin cleaves proteins large polypeptides into smaller polypeptides and some amino acids. -in the small intestine when polypeptides enter the small intestine, several pan- creatic and intestinal proteases hydrolyze them further into short peptide chains, tripeptides, dipeptides, and amino acids. -then peptidase enzymes on the mem- brane surfaces of the intestinal cells split most of the dipeptides and tripeptides into single amino acids. -only a few peptides escape digestion and enter the blood intact. -figure 6-6 includes names of the digestive enzymes for protein and describes their actions. -protein absorption a number of specific carriers transport amino acids (and some dipeptides and tripeptides) into the intestinal cells. -once inside the intestinal cells, amino acids may be used for energy or to synthesize needed compounds. -amino acids that are not used by the intestinal cells are transported across the cell membrane into the sur- rounding fluid where they enter the capillaries on their way to the liver. -consumers lacking nutrition knowledge may fail to realize that most pro- teins are broken down to amino acids before absorption. -they may be mislead by advertisements urging them to eat enzyme a. it will help you digest your food. -or don t eat food b. it contains enzyme c, which will digest cells in your body. -in reality, though, enzymes in foods are digested, just as all pro- teins are. -even the digestive enzymes which function optimally at their spe- cific ph are denatured and digested when the ph of their environment changes. -(for example, the enzyme pepsin, which works best in the low ph of the stomach becomes inactive and digested when it enters the higher ph of the small intestine.) -another misconception is that eating predigested proteins (amino acid supple- ments) saves the body from having to digest proteins and keeps the digestive sys- tem from overworking. -such a belief grossly underestimates the body s abilities. -as a matter of fact, the digestive system handles whole proteins better than predi- gested ones because it dismantles and absorbs the amino acids at rates that are op- timal for the body s use. -(the last section of this chapter discusses amino acid supplements further.) -protein: amino acids 185 the inactive form of an enzyme is called a proenzyme or a zymogen (zye-moh-jen). -a string of four to nine amino acids is an oligopeptide (ol-ee-go-pep-tide). -oligo = few pepsin: a gastric enzyme that hydrolyzes protein. -pepsin is secreted in an inactive form, pepsinogen, which is activated by hydrochloric acid in the stomach. -proteases (pro-tee-aces): enzymes that hydrolyze protein. -peptidase: a digestive enzyme that hydrolyzes peptide bonds. -tripeptidases cleave tripeptides; dipeptidases cleave dipeptides. -endopeptidases cleave peptide bonds within the chain to create smaller fragments, whereas exopeptidases cleave bonds at the ends to release free amino acids. -tri = three di = two endo = within exo = outside 186 chapter 6 figure 6-6 animated! -protein digestion in the gi tract to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow salivary glands mouth (esophagus) stomach (liver) (gallbladder) pancreatic duct pancreas protein mouth and salivary glands chewing and crushing moisten protein-rich foods and mix them with saliva to be swallowed stomach hydrochloric acid (hcl) uncoils protein strands and activates stomach enzymes: pepsin, hci protein smaller polypeptides hydrochloric acid and the digestive enzymes in the stomach: hydrochloric acid (hcl) (cid:129) denatures protein structure (cid:129) activates pepsinogen to pepsin pepsin (cid:129) cleaves proteins to smaller polypeptides and some free amino acids (cid:129) inhibits pepsinogen synthesis small intestine and pancreas pancreatic and small intestinal enzymes split polypeptides further: pancreatic and intestinal proteases poly- peptides tripeptides, dipeptides, amino acids in the small intestine: enteropeptidasea (cid:129) converts pancreatic trypsinogen to trypsin trypsin (cid:129) inhibits trypsinogen synthesis (cid:129) cleaves peptide bonds next to the amino acids lysine and then enzymes on the surface of the small intestinal cells hydrolyze these peptides and the cells absorb them: intestinal tripeptidases and dipeptidases peptides amino acids (absorbed) small intestine arginine (cid:129) converts pancreatic procarboxypeptidases to carboxypeptidases (cid:129) converts pancreatic chymotrypsinogen to chymotrypsin chymotrypsin (cid:129) cleaves peptide bonds next to the amino acids phenylalanine, tyrosine, tryptophan, methionine, asparagine, and histidine carboxypeptidases (cid:129) cleave amino acids from the acid (carboxyl) ends of polypeptides elastase and collagenase (cid:129) cleave polypeptides into smaller polypeptides and tripeptides intestinal tripeptidases (cid:129) cleave tripeptides to dipeptides and amino acids intestinal dipeptidases (cid:129) cleave dipeptides to amino acids intestinal aminopeptidases (cid:129) cleave amino acids from the amino ends of small polypeptides (oligopeptides) a enteropeptidase was formerly known as enterokinase. -protein: amino acids 187 in summary digestion is facilitated mostly by the stomach s acid and enzymes, which first denature dietary proteins, then cleave them into smaller polypeptides and some amino acids. -pancreatic and intestinal enzymes split these polypeptides further, to oligo-, tri-, and dipeptides, and then split most of these to single amino acids. -then carriers in the membranes of intestinal cells transport the amino acids into the cells, where they are released into the bloodstream. -proteins in the body the human body contains an estimated 30,000 different kinds of proteins. -of these, about 3000 have been studied, although with the recent surge in knowl- edge gained from sequencing the human genome, this number is growing rap- idly. -only about 10 are described in this chapter but these should be enough to illustrate the versatility, uniqueness, and importance of proteins. -as you will see, each protein has a specific function, and that function is determined during pro- tein synthesis. -the study of the body s proteins is called proteomics. -reminder: the human genome is the full set of chromosomes, including all of the genes and associated dna. -protein synthesis each human being is unique because of small differences in the body s proteins. -these differences are determined by the amino acid sequences of proteins, which, in turn, are determined by genes. -the following paragraphs describe in words the ways cells synthesize proteins; figure 6-7 (p. 188) provides a pictorial description. -the instructions for making every protein in a person s body are transmitted by way of the genetic information received at conception. -this body of knowledge, which is filed in the dna (deoxyribonucleic acid) within the nucleus of every cell, never leaves the nucleus. -delivering the instructions transforming the information in dna into the ap- propriate sequence of amino acids needed to make a specific protein requires two major steps. -in the first step, a stretch of dna is used as a template to make a strand of rna (ribonucleic acid) known as messenger rna. -messenger rna then carries the code across the nuclear membrane into the body of the cell. -there it seeks out and attaches itself to one of the ribosomes (a protein-making machine, which is itself composed of rna and protein), where the second step takes place. -situated on a ribosome, messenger rna specifies the sequence in which the amino acids line up for the synthesis of a protein. -lining up the amino acids other forms of rna, called transfer rna, collect amino acids from the cell fluid and bring them to the messenger. -each of the 20 amino acids has a specific transfer rna. -thousands of transfer rnas, each carrying its amino acid, cluster around the ribosomes, awaiting their turn to unload. -when the messenger s list calls for a specific amino acid, the transfer rna carrying that amino acid moves into position. -then the next loaded transfer rna moves into place and then the next and the next. -in this way, the amino acids line up in the se- quence that is called for, and enzymes bind them together. -finally, the completed protein strand is released, and the transfer rnas are freed to return for other loads of amino acids. -sequencing errors the sequence of amino acids in each protein determines its shape, which supports a specific function. -if a genetic error alters the amino acid se- quence of a protein, or if a mistake is made in copying the sequence, an altered pro- tein will result, sometimes with dramatic consequences. -the protein hemoglobin this process of messenger rna being made from a template of dna is known as transcription. -this process of messenger rna directing the sequence of amino acids and synthesis of proteins is known as translation. -188 chapter 6 figure 6-7 animated! -protein synthesis cell dna nucleus mrna dna ribosomes (protein-making machinery) 2 the mrna leaves the nucleus through the nuclear membrane. -dna remains inside the nucleus. -1 3 4 the dna serves as a template to make strands of messenger rna (mrna). -each mrna strand copies exactly the instructions for making some protein the cell needs. -the mrna attaches itself to the protein- making machinery of the cell, the ribosomes. -ribosome m r n a another form of rna, transfer rna (trna), collects amino acids from the cell fluid. -each trna carries its amino acids to the mrna, which dictates the sequence in which the amino acids will be attached to form the protein strands. -thus the mrna ensures the amino acids are lined up in the correct sequence. -amino acid trna m r n a 5 as the amino acids are lined up in the right sequence, and the ribosome moves along the mrna, an enzyme bonds one amino acid after another to the growing protein strand. -the trna are freed to return for more amino acids. -when all the amino acids have been attached, the completed protein is released. -protein strand m r n a 6 finally, the mrna and ribosome separate. -it takes many words to describe these events, but in the cell, 40 to 100 amino acids can be added to a growing protein strand in only a second. -furthermore several ribosomes can simultaneously work on the same mrna to make many copies of the protein. -to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow offers one example of such a genetic variation. -in a person with sickle-cell anemia, two of hemoglo- bin s four polypeptide chains (described earlier on p. 184) have the normal sequence of amino acids, but the other two chains do not they have the amino acid valine in a position that is normally occupied by glutamic acid (see figure 6-8). -this single alteration in the amino acid sequence changes the characteristics and shape of hemoglobin so much that it loses its abil- ity to carry oxygen effectively. -the red blood cells filled with this abnormal hemoglobin stiffen into elongated sickle, or crescent, shapes instead of maintaining their normal pliable disc shape hence the name, sickle-cell anemia. -sickle-cell anemia raises energy needs, causes many medical problems, and can be fatal.1 caring for children with sickle-cell anemia includes diligent at- tention to their water needs; dehydration can trigger a crisis. -nutrients and gene expression when a cell makes a protein as described earlier, scientists say that the gene for that protein has been expressed. -cells can regulate gene expression to make the type of protein, in the amounts and at the rate, they need. -nearly all of the body s cells possess the genes for mak- ing all human proteins, but each type of cell makes only the proteins it needs. -for example, cells of the pancreas express the gene for insulin; in other cells, that gene is idle. -similarly, the cells of the pancreas do not make the protein hemoglobin, which is needed only by the red blood cells. -protein: amino acids 189 figure 6-8 sickle cell compared with normal red blood cell normally, red blood cells are disc-shaped, but in the inherited disor- der sickle-cell anemia, red blood cells are sickle- or crescent-shaped. -this alteration in shape occurs because valine replaces glutamic acid in the amino acid sequence of two of hemoglobin s polypeptide chains. -as a result of this one alteration, the hemoglobin has a diminished capacity to carry oxygen. -photo to be placed d e t i m i l n u s l a u s i v / r e l g e i f y e l n a t s . -r d sickle-shaped blood cell normal red blood cell amino acid sequence of normal hemoglobin: val his leu thr pro glu glu amino acid sequence of sickle-cell hemoglobin: val his leu thr pro val glu recent research has unveiled some of the fascinat- ing ways nutrients regulate gene expression and pro- tein synthesis (see highlight 6). -because diet plays an ongoing role in our lives from conception to death, it has a major influence on gene expression and disease development.2 the benefits of polyunsaturated fatty acids in defending against heart disease, for example, are partially ex- plained by their role in influencing gene expression for lipid enzymes. -later chapters provide additional examples of relationships among nutrients, genes, and disease development. -in summary cells synthesize proteins according to the genetic information provided by the dna in the nucleus of each cell. -this information dictates the order in which amino acids must be linked together to form a given protein. -sequencing er- rors occasionally occur, sometimes with significant consequences. -roles of proteins whenever the body is growing, repairing, or replacing tissue, proteins are involved. -sometimes their role is to facilitate or to regulate; other times it is to become part of a structure. -versatility is a key feature of proteins. -anemia is not a disease, but a symptom of various diseases. -in the case of sickle-cell anemia, a defect in the hemoglobin molecule changes the shape of the red blood cells. -later chapters describe the anemias of vitamin and mineral deficiencies. -in all cases, the abnormal blood cells are unable to meet the body s oxygen demands. -nutrients can play key roles in activating or silencing genes. -switching genes on and off, without changing the genetic sequence itself, is known as epigenetics. -epi = among sickle-cell anemia: a hereditary form of anemia characterized by abnormal sickle- or crescent-shaped red blood cells. -sickled cells interfere with oxygen transport and blood flow. -symptoms are precipitated by dehydration and insufficient oxygen (as may occur at high altitudes) and include hemolytic anemia (red blood cells burst), fever, and severe pain in the joints and abdomen. -gene expression: the process by which a cell converts the genetic code into rna and protein. -190 chapter 6 figure 6-9 enzyme action each enzyme facilitates a specific chemical reaction. -in this diagram, an enzyme enables two compounds to make a more complex structure, but the enzyme itself remains unchanged. -b a enzyme the separate compounds, a and b, are attracted to the enzyme s active site, making a reaction likely. -a b enzyme a b new compound enzyme the enzyme forms a complex with a and b. the enzyme is unchanged, but a and b have formed a new compound, ab. -as building materials for growth and maintenance from the moment of conception, proteins form the building blocks of muscles, blood, and skin in fact, of most body structures. -for example, to build a bone or a tooth, cells first lay down a matrix of the protein collagen and then fill it with crystals of calcium, phosphorus, magnesium, fluoride, and other minerals. -collagen also provides the material of liga- ments and tendons and the strengthening glue between the cells of the artery walls that enables the arteries to withstand the pressure of the blood surging through them with each heartbeat. -also made of collagen are scars that knit the sepa- rated parts of torn tissues together. -proteins are also needed for replacing dead or damaged cells. -the life span of a skin cell is only about 30 days. -as old skin cells are shed, new cells made largely of protein grow from underneath to replace them. -cells in the deeper skin layers synthesize new proteins to go into hair and fingernails. -muscle cells make new proteins to grow larger and stronger in response to exer- cise. -cells of the gi tract are replaced every few days. -both inside and outside, then, the body continuously deposits protein into the new cells that replace those that have been lost. -as enzymes some proteins act as enzymes. -digestive enzymes have appeared in every chapter since chapter 3, but digestion is only one of the many processes facil- itated by enzymes. -enzymes not only break down substances, but they also build substances (such as bone) and transform one substance into another (amino acids into glucose, for example). -figure 6-9 diagrams a synthesis reaction. -an analogy may help to clarify the role of enzymes. -enzymes are comparable to the clergy and judges who make and dissolve marriages. -when a minister mar- ries two people, they become a couple, with a new bond between them. -they are joined together but the minister remains unchanged. -the minister represents en- zymes that synthesize large compounds from smaller ones. -one minister can per- form thousands of marriage ceremonies, just as one enzyme can perform billions of synthetic reactions. -similarly, a judge who lets married couples separate may decree many divorces before retiring. -the judge represents enzymes that hydrolyze larger compounds to smaller ones; for example, the digestive enzymes. -the point is that, like the minis- ter and the judge, enzymes themselves are not altered by the reactions they facili- tate. -they are catalysts, permitting reactions to occur more quickly and efficiently than if substances depended on chance encounters alone. -as hormones the body s many hormones are messenger molecules, and some hormones are proteins. -various endocrine glands in the body release hormones in response to changes that challenge the body. -the blood carries the hormones from these glands to their target tissues, where they elicit the appropriate responses to re- store and maintain normal conditions. -the hormone insulin provides a familiar example. -when blood glucose rises, the pancreas releases its insulin. -insulin stimulates the transport proteins of the muscles and adipose tissue to pump glucose into the cells faster than it can leak out. -(after acting on the message, the cells destroy the insulin.) -then, as blood glu- cose falls, the pancreas slows its release of insulin. -many other proteins act as hor- mones, regulating a variety of actions in the body (see table 6-2 for examples). -as regulators of fluid balance proteins help to maintain the body s fluid balance. -figure 12-1 in chapter 12 illustrates a cell and its associated fluids. -as the figure explains, the body s fluids are contained inside the cells (intracellular) breaking down reactions are catabolic, whereas building up reactions are anabolic. -(chapter 7 provides more details.) -recall from chapter 5 that some hormones, such as estrogen and testosterone, derive from cholesterol. -matrix (may-tricks): the basic substance that gives form to a developing structure; in the body, the formative cells from which teeth and bones grow. -collagen (kol-ah-jen): the protein from which connective tissues such as scars, tendons, ligaments, and the foundations of bones and teeth are made. -enzymes: proteins that facilitate chemical reactions without being changed in the process; protein catalysts. -fluid balance: maintenance of the proper types and amounts of fluid in each compartment of the body fluids (see also chapter 12). -or outside the cells (extracellular). -extracellular fluids, in turn, can be found either in the spaces between the cells (interstitial) or within the blood vessels (intravascu- lar). -the fluid within the intravascular spaces is called plasma (essentially blood without its red blood cells). -fluids can flow freely between these compartments, but being large, proteins cannot. -proteins are trapped primarily within the cells and to a lesser extent in the plasma. -the exchange of materials between the blood and the cells takes place across the capillary walls, which allow the passage of fluids and a variety of materials but usually not plasma proteins. -still some plasma proteins leak out of the capillaries into the interstitial fluid between the cells. -these proteins cannot be reabsorbed back into the plasma; they normally reenter circulation via the lymph system. -if plasma proteins enter the interstitial spaces faster than they can be cleared, fluid accumulates (because plasma proteins attract water) and causes swelling. -swelling due to an excess of interstitial fluid is known as edema. -the protein-related causes of edema include: excessive protein losses caused by kidney disease or large wounds (such as ex- tensive burns) inadequate protein synthesis caused by liver disease inadequate dietary intake of protein whatever the cause of edema, the result is the same: a diminished capacity to de- liver nutrients and oxygen to the cells and to remove wastes from them. -as a conse- quence, cells fail to function adequately. -as acid-base regulators proteins also help to maintain the balance between acids and bases within the body fluids. -normal body processes continually pro- duce acids and bases, which the blood carries to the kidneys and lungs for excretion. -the challenge is to do this without upsetting the blood s acid-base balance. -in an acid solution, hydrogen ions (h+) abound; the more hydrogen ions, the more concentrated the acid. -proteins, which have negative charges on their sur- faces, attract hydrogen ions, which have positive charges. -by accepting and releas- ing hydrogen ions, proteins maintain the acid-base balance of the blood and body fluids. -the blood s acid-base balance is tightly controlled. -the extremes of acidosis and alkalosis lead to coma and death, largely because they denature working proteins. -disturbing a protein s shape renders it useless. -to give just one example, denatured hemoglobin loses its capacity to carry oxygen. -as transporters some proteins move about in the body fluids, carrying nutrients and other molecules. -the protein hemoglobin carries oxygen from the lungs to the cells. -the lipoproteins transport lipids around the body. -special transport proteins carry vitamins and minerals. -the transport of the mineral iron provides an especially good illustration of these proteins specificity and precision. -when iron enters an intestinal cell after a meal has been digested and absorbed, it is captured by a protein. -before leaving the intestinal cell, iron is attached to another protein that carries it though the bloodstream to the cells. -once iron enters a cell, it is attached to a storage protein that will hold the iron until it is needed. -when it is needed, iron is incorporated into proteins in the red blood cells and muscles that assist in oxygen transport and use. -(chapter 13 provides more details on how these protein carriers transport and store iron.) -some transport proteins reside in cell membranes and act as pumps, picking up compounds on one side of the membrane and releasing them on the other as needed. -each transport protein is specific for a certain compound or group of re- lated compounds. -figure 6-10 (p. 192) illustrates how a membrane-bound trans- port protein helps to maintain the sodium and potassium concentrations in the fluids inside and outside cells. -the balance of these two minerals is critical to nerve transmissions and muscle contractions; imbalances can cause irregular heartbeats, muscular weakness, kidney failure, and even death. -protein: amino acids 191 table 6-2 and their actions examples of hormones hormones actions growth hormone promotes growth insulin and glucagon thyroxin regulate blood glucose (see chapter 4) regulates the body s metabolic rate (see chapter 8) calcitonin and parathyroid hormone regulate blood calcium (see chapter 12) antidiuretic hormone regulates fluid and electrolyte balance (see chapter 12) note: hormones are chemical messengers that are secreted by endocrine glands in response to altered conditions in the body. -each travels to one or more specific target tissues or organs, where it elicits a specific response. -for descriptions of many hormones important in nutrition, see appendix a. compounds that help keep a solution s acid- ity or alkalinity constant are called buffers. -edema (eh-deem-uh): the swelling of body tissue caused by excessive amounts of fluid in the interstitial spaces; seen in protein deficiency (among other conditions). -acids: compounds that release hydrogen ions in a solution. -bases: compounds that accept hydrogen ions in a solution. -acidosis (assi-doe-sis): above-normal acidity in the blood and body fluids. -alkalosis (alka-loe-sis): above-normal alkalinity (base) in the blood and body fluids. -192 chapter 6 figure 6-10 animated! -an example of protein transport this transport protein resides within a cell membrane and acts as a two-door passageway. -molecules enter on one side of the mem- brane and exit on the other, but the protein doesn t leave the membrane. -this example shows how the transport protein moves sodium and potassium in opposite directions across the membrane to maintain a high concentration of potassium and a low concen- tration of sodium within the cell. -this active transport system requires energy. -key: sodium potassium cell membrane to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow outside cell inside cell transport protein the transport protein picks up sodium from inside the cell. -the protein changes shape and releases sodium outside the cell. -the transport protein picks up potassium from outside the cell. -the protein changes shape and releases potassium inside the cell. -as antibodies proteins also defend the body against disease. -a virus whether it is one that causes flu, smallpox, measles, or the common cold enters the cells and multiplies there. -one virus may produce 100 replicas of itself within an hour or so. -each replica can then burst out and invade 100 different cells, soon yielding 10,000 virus particles, which invade 10,000 cells. -left free to do their worst, they will soon overwhelm the body with disease. -fortunately, when the body detects these invading antigens, it manufac- tures antibodies, giant protein molecules designed specifically to combat them. -the antibodies work so swiftly and efficiently that in a normal, healthy individual, most diseases never have a chance to get started. -without sufficient protein, though, the body cannot maintain its army of antibodies to resist infec- tious diseases. -each antibody is designed to destroy a specific antigen. -once the body has man- ufactured antibodies against a particular antigen (such as the measles virus), it re- members how to make them. -consequently, the next time the body encounters that same antigen, it produces antibodies even more quickly. -in other words, the body develops a molecular memory, known as immunity. -(chapter 16 describes food allergies the immune system s response to food antigens.) -as a source of energy and glucose without energy, cells die; without glucose, the brain and nervous system falter. -even though proteins are needed to do the work that only they can perform, they will be sacrificed to provide energy and glucose during times of starvation or insufficient carbohydrate intake. -the body will break down its tissue proteins to make amino acids available for energy or glucose produc- tion. -in this way, protein can maintain blood glucose levels, but at the expense of los- ing lean body tissue. -chapter 7 provides many more details on energy metabolism. -other roles as mentioned earlier, proteins form integral parts of most body struc- tures such as skin, muscles, and bones. -they also participate in some of the body s most amazing activities such as blood clotting and vision. -when a tissue is injured, a rapid chain of events leads to the production of fibrin, a stringy, insoluble mass of protein fibers that forms a solid clot from liquid blood. -later, more slowly, the pro- tein collagen forms a scar to replace the clot and permanently heal the wound. -the light-sensitive pigments in the cells of the eye s retina are molecules of the protein opsin. -opsin responds to light by changing its shape, thus initiating the nerve im- pulses that convey the sense of sight to the brain. -reminder: protein provides 4 kcal/g. -return to p. 9 for a refresher on how to calculate the protein kcalories from foods. -reminder: the making of glucose from non- carbohydrate sources such as amino acids is gluconeogenesis. -antigens: substances that elicit the formation of antibodies or an inflammation reaction from the immune system. -a bacterium, a virus, a toxin, and a protein in food that causes allergy are all examples of antigens. -antibodies: large proteins of the blood and body fluids, produced by the immune system in response to the invasion of the body by foreign molecules (usually proteins called antigens). -antibodies combine with and inactivate the foreign invaders, thus protecting the body. -immunity: the body s ability to defend itself against diseases (see also chapter 18). -in summary the protein functions discussed here are summarized in the accompanying table. -they are only a few of the many roles proteins play, but they convey some sense of the immense variety of proteins and their importance in the body. -growth and maintenance enzymes hormones fluid balance acid-base balance transportation antibodies energy and glucose proteins form integral parts of most body struc- tures such as skin, tendons, membranes, mus- cles, organs, and bones. -as such, they support the growth and repair of body tissues. -proteins facilitate chemical reactions. -proteins regulate body processes. -(some, but not all, hormones are proteins.) -proteins help to maintain the volume and com- position of body fluids. -proteins help maintain the acid-base balance of body fluids by acting as buffers. -s i b r o c / y e l l e k s l e i r a proteins transport substances, such as lipids, vitamins, minerals, and oxygen, around the body. -proteins inactivate foreign invaders, thus protecting the body against diseases. -proteins provide some fuel, and glucose if needed, for the body s energy needs. -protein: amino acids 193 growing children end each day with more bone, blood, muscle, and skin cells than they had at the beginning of the day. -a preview of protein metabolism this section previews protein metabolism; chapter 7 provides a full description. -cells have several metabolic options, depending on their protein and energy needs. -protein turnover and the amino acid pool within each cell, proteins are continually being made and broken down, a process known as protein turnover. -when proteins break down, they free amino acids. -these amino acids mix with amino acids from dietary protein to form an amino acid pool within the cells and circulating blood. -the rate of protein degradation and the amount of protein intake may vary, but the pattern of amino acids within the pool remains fairly con- stant. -regardless of their source, any of these amino acids can be used to make body proteins or other nitrogen-containing compounds, or they can be stripped of their nitrogen and used for energy (either immediately or stored as fat for later use). -nitrogen balance protein turnover and nitrogen balance go hand in hand. -in healthy adults, protein synthesis balances with degradation, and protein intake from food balances with nitrogen excretion in the urine, feces, and sweat. -when nitrogen in- take equals nitrogen output, the person is in nitrogen equilibrium, or zero nitrogen balance. -researchers use nitrogen balance studies to estimate protein requirements.3 if the body synthesizes more than it degrades and adds protein, nitrogen status becomes positive. -nitrogen status is positive in growing infants, children, adoles- cents, pregnant women, and people recovering from protein deficiency or illness; their nitrogen intake exceeds their nitrogen output. -they are retaining protein in new tissues as they add blood, bone, skin, and muscle cells to their bodies. -if the body degrades more than it synthesizes and loses protein, nitrogen status becomes negative. -nitrogen status is negative in people who are starving or suffer- ing other severe stresses such as burns, injuries, infections, and fever; their nitrogen * the genetic materials dna and rna contain nitrogen, but the quantity is insignificant compared with the amount in protein. -protein is 16 percent nitrogen. -said another way, the average protein weighs about 6.25 times as much as the nitrogen it contains, so scientists can estimate the amount of protein in a sample of food, body tissue, or other material by multiplying the weight of the nitrogen in it by 6.25. amino acids (or proteins) that derive from within the body are endogenous (en- dodge-eh-nus). -in contrast, those that de- rive from foods are exogenous (eks-odge-eh-nus). -endo = within gen = arising exo = outside (the body) nitrogen balance: nitrogen equilibrium (zero nitrogen balance): n in = n out. -positive nitrogen: n in (cid:2) n out. -negative nitrogen: n in (cid:3) n out. -protein turnover: the degradation and synthesis of protein. -amino acid pool: the supply of amino acids derived from either food proteins or body proteins that collect in the cells and circulating blood and stand ready to be incorporated in proteins and other compounds or used for energy. -nitrogen balance: the amount of nitrogen consumed (n in) as compared with the amount of nitrogen excreted (n out) in a given period of time. -* 194 chapter 6 neurotransmitters: chemicals that are released at the end of a nerve cell when a nerve impulse arrives there. -they diffuse across the gap to the next cell and alter the membrane of that second cell to either inhibit or excite it. -deamination (dee-am-ih-nay-shun): removal of the amino (nh2) group from a compound such as an amino acid. -output exceeds their nitrogen intake. -during these times, the body loses nitrogen as it breaks down muscle and other body proteins for energy. -using amino acids to make proteins or nonessential amino acids as mentioned, cells can assemble amino acids into the proteins they need to do their work. -if a particular nonessential amino acid is not readily available, cells can make it from another amino acid. -if an essential amino acid is missing, the body may break down some of its own proteins to obtain it. -using amino acids to make other compounds cells can also use amino acids to make other compounds. -for example, the amino acid tyrosine is used to make the neurotransmitters norepinephrine and epinephrine, which relay nervous system messages throughout the body. -tyrosine can also be made into the pigment melanin, which is responsible for brown hair, eye, and skin color, or into the hormone thy- roxin, which helps to regulate the metabolic rate. -for another example, the amino acid tryptophan serves as a precursor for the vitamin niacin and for serotonin, a neu- rotransmitter important in sleep regulation, appetite control, and sensory perception. -using amino acids for energy and glucose as mentioned earlier, when glu- cose or fatty acids are limited, cells are forced to use amino acids for energy and glu- cose. -the body does not make a specialized storage form of protein as it does for carbohydrate and fat. -glucose is stored as glycogen in the liver and fat as triglyc- erides in adipose tissue, but protein in the body is available only from the working and structural components of the tissues. -when the need arises, the body breaks down its tissue proteins and uses their amino acids for energy or glucose. -thus, over time, energy deprivation (starvation) always causes wasting of lean body tissue as well as fat loss. -an adequate supply of carbohydrates and fats spares amino acids from being used for energy and allows them to perform their unique roles. -deaminating amino acids when amino acids are broken down (as occurs when they are used for energy), they are first deaminated stripped of their nitro- gen-containing amino groups. -deamination produces ammonia, which the cells release into the bloodstream. -the liver picks up the ammonia, converts it into urea (a less toxic compound), and returns the urea to the blood. -the production of urea increases as dietary protein increases, until production hits its maximum rate at in- takes approaching 250 grams per day. -(urea metabolism is described in chapter 7.) -the kidneys filter urea out of the blood; thus the amino nitrogen ends up in the urine. -the remaining carbon fragments of the deaminated amino acids may enter a number of metabolic pathways for example, they may be used for energy or for the production of glucose, ketones, cholesterol, or fat. -using amino acids to make fat amino acids may be used to make fat when en- ergy and protein intakes exceed needs and carbohydrate intake is adequate. -the amino acids are deaminated, the nitrogen is excreted, and the remaining carbon fragments are converted to fat and stored for later use. -in this way, protein-rich foods can contribute to weight gain. -in summary proteins are constantly being synthesized and broken down as needed. -the body s assimilation of amino acids into proteins and its release of amino acids via protein degradation and excretion can be tracked by measuring nitrogen balance, which should be positive during growth and steady in adulthood. -an energy deficit or an inadequate protein intake may force the body to use amino acids as fuel, creating a negative nitrogen balance. -protein eaten in ex- cess of need is degraded and stored as body fat. -chemists sometimes classify amino acids according to the destinations of their carbon fragments after deamination. -if the fragment leads to the production of glucose, the amino acid is called glucogenic; if it leads to the formation of ketone bodies, fats, and sterols, the amino acid is called ketogenic. -there is no sharp distinction between glucogenic and ketogenic amino acids, however. -a few are both, most are considered glucogenic, only one (leucine) is clearly ketogenic. -protein in foods in the united states and canada, where nutritious foods are abundant, most people eat protein in such large quantities that they receive all the amino acids they need. -in countries where food is scarce and the people eat only marginal amounts of pro- tein-rich foods, however, the quality of the protein becomes crucial. -protein quality the protein quality of the diet determines, in large part, how well children grow and how well adults maintain their health. -put simply, high-quality proteins provide enough of all the essential amino acids needed to support the body s work, and low- quality proteins don t. two factors influence protein quality the protein s digestibil- ity and its amino acid composition. -digestibility as explained earlier, proteins must be digested before they can pro- vide amino acids. -protein digestibility depends on such factors as the protein s source and the other foods eaten with it. -the digestibility of most animal proteins is high (90 to 99 percent); plant proteins are less digestible (70 to 90 percent for most, but over 90 percent for soy and legumes). -amino acid composition to make proteins, a cell must have all the needed amino acids available simultaneously. -the liver can produce any nonessential amino acid that may be in short supply so that the cells can continue linking amino acids into protein strands. -if an essential amino acid is missing, though, a cell must dismantle its own proteins to obtain it. -therefore, to prevent protein breakdown, di- etary protein must supply at least the nine essential amino acids plus enough nitro- gen-containing amino groups and energy for the synthesis of the others. -if the diet supplies too little of any essential amino acid, protein synthesis will be limited. -the body makes whole proteins only; if one amino acid is missing, the others cannot form a partial protein. -an essential amino acid supplied in less than the amount needed to support protein synthesis is called a limiting amino acid. -reference protein the quality of a food protein is determined by comparing its amino acid composition with the essential amino acid requirements of preschool- age children. -such a standard is called a reference protein. -the rationale be- hind using the requirements of this age group is that if a protein will effectively support a young child s growth and development, then it will meet or exceed the re- quirements of older children and adults. -high-quality proteins as mentioned earlier, a high-quality protein contains all the essential amino acids in relatively the same amounts and proportions that hu- man beings require; it may or may not contain all the nonessential amino acids. -proteins that are low in an essential amino acid cannot, by themselves, support pro- tein synthesis. -generally, foods derived from animals (meat, fish, poultry, cheese, eggs, yogurt, and milk) provide high-quality proteins, although gelatin is an excep- tion. -(it lacks tryptophan and cannot support growth and health as a diet s sole pro- tein.) -proteins from plants (vegetables, nuts, seeds, grains, and legumes) have more diverse amino acid patterns and tend to be limiting in one or more essential amino acids. -some plant proteins are notoriously low quality (for example, corn protein). -a few others are high quality (for example, soy protein). -researchers have developed several methods for evaluating the quality of food proteins and identifying high-quality proteins. -appendix d provides details. -complementary proteins in general, plant proteins are lower quality than an- imal proteins, and plants also offer less protein (per weight or measure of food). -for this reason, many vegetarians improve the quality of proteins in their diets by com- bining plant-protein foods that have different but complementary amino acid pat- terns. -this strategy yields complementary proteins that together contain all the protein: amino acids 195 . -c n i s o i d u t s a r a l o p black beans and rice, a favorite hispanic com- bination, together provide a balanced array of amino acids. -in the past, egg protein was commonly used as the reference protein. -table d-1 in appen- dix d presents the amino acid profile of egg. -as the reference protein, egg was assigned the value of 100; table d-3 includes scores of other food proteins for comparison. -high-quality proteins: dietary proteins containing all the essential amino acids in relatively the same amounts that human beings require. -they may also contain nonessential amino acids. -protein digestibility: a measure of the amount of amino acids absorbed from a given protein intake. -limiting amino acid: the essential amino acid found in the shortest supply relative to the amounts needed for protein synthesis in the body. -four amino acids are most likely to be limiting: lysine methionine threonine tryptophan reference protein: a standard against which to measure the quality of other proteins. -complementary proteins: two or more dietary proteins whose amino acid assortments complement each other in such a way that the essential amino acids missing from one are supplied by the other. -196 chapter 6 figure 6-11 complementary proteins in general, legumes provide plenty of isoleucine (ile) and lysine (lys) but fall short in methionine (met) and trypto- phan (trp). -grains have the opposite strengths and weaknesses, making them a perfect match for legumes. -ile lys met trp legumes grains together daily value: 50 g protein (based on 10% of 2000 kcal diet) essential amino acids in quantities sufficient to support health. -the protein quality of the combination is greater than for either food alone (see figure 6-11). -many people have long believed that combining plant proteins at every meal is critical to protein nutrition. -for most healthy vegetarians, though, it is not nec- essary to balance amino acids at each meal if protein intake is varied and energy intake is sufficient.4 vegetarians can receive all the amino acids they need over the course of a day by eating a variety of whole grains, legumes, seeds, nuts, and veg- etables. -protein deficiency will develop, however, when fruits and certain vegeta- bles make up the core of the diet, severely limiting both the quantity and quality of protein. -highlight 2 describes how to plan a nutritious vegetarian diet. -in summary a diet that supplies all of the essential amino acids in adequate amounts en- sures protein synthesis. -the best guarantee of amino acid adequacy is to eat foods containing high-quality proteins or mixtures of foods containing com- plementary proteins that can each supply the amino acids missing in the other. -in addition to its amino acid content, the quality of protein is measured by its digestibility and its ability to support growth. -such measures are of great importance in dealing with malnutrition worldwide, but in the united states and canada, where protein deficiency is not common, protein quality scores of individual foods deserve little emphasis. -protein regulations for food labels all food labels must state the quantity of protein in grams. -the % daily value for protein is not mandatory on all labels but is required whenever a food makes a protein claim or is intended for consumption by children under four years old. -whenever the daily value percentage is declared, researchers must determine the quality of the protein. -thus, when a % daily value is stated for protein, it reflects both quantity and quality. -health effects and recommended intakes of protein as you know by now, protein is indispensable to life. -it should come as no surprise that protein deficiency can have devastating effects on people s health. -but, like the other nutrients, protein in excess can also be harmful. -this section examines the health effects and recommended intakes of protein. -s o t o h p d l r o w e d i w / p a protein-energy malnutrition when people are deprived of protein, energy, or both, the result is protein-energy malnutrition (pem). -although pem touches many adult lives, it most often strikes early in childhood. -it is one of the most prevalent and devastating forms of malnu- trition in the world, afflicting one of every four children worldwide. -most of the 33,000 children who die each day are malnourished.5 inadequate food intake leads to poor growth in children and to weight loss and wasting in adults. -children who are thin for their height may be suffering from for labeling purposes, the daily values for protein are as follows: for infants, 14 grams; for children under age four, 16 grams; for older children and adults, 50 grams; for pregnant women, 60 grams; and for lactating women, 65 grams. -donated food saves some people from starva- tion, but it is usually insufficient to meet nutri- ent needs or even to defend against hunger. -protein-energy malnutrition (pem), also called protein-kcalorie malnutrition (pcm): a deficiency of protein, energy, or both, including kwashiorkor, marasmus, and instances in which they overlap (see p. 198). -acute pem (recent severe food deprivation), whereas children who are short for their age have experienced chronic pem (long-term food deprivation). -poor growth due to pem is easy to overlook because a small child may look quite nor- mal, but it is the most common sign of malnutrition. -pem is most prevalent in africa, central america, south america, and east and southeast asia. -in the united states, homeless people and those living in substandard housing in inner cities and rural areas have been diagnosed with pem. -in addition to those living in poverty, elderly people who live alone and adults who are addicted to drugs and alcohol are frequently victims of pem. -pem can develop in young children when parents mistakenly provide health-food beverages that lack adequate en- ergy or protein instead of milk, most commonly because of nutritional ignorance, perceived milk intolerance, or food faddism. -adult pem is also seen in people hospi- talized with infections such as aids or tuberculosis; these infections deplete body pro- teins, demand extra energy, induce nutrient losses, and alter metabolic pathways. -furthermore, poor nutrient intake during hospitalization worsens malnutrition and impairs recovery, whereas nutrition intervention often improves the body s response to other treatments and the chances of survival. -pem is also common in those suffer- ing from the eating disorder anorexia nervosa (discussed in highlight 8). -prevention emphasizes frequent, nutrient-dense, energy-dense meals and, equally important, resolution of the underlying causes of pem poverty, infections, and illness. -classifying pem pem occurs in two forms: marasmus and kwashiorkor, which differ in their clinical features (see table 6-3). -the following paragraphs present three clinical syndromes marasmus, kwashiorkor, and the combination of the two. -marasmus appropriately named from the greek word meaning dying away, marasmus reflects a severe deprivation of food over a long time (chronic pem). -put simply, the person is starving and suffering from an inadequate energy and protein intake (and inadequate essential fatty acids, vitamins, and minerals as well). -marasmus occurs most commonly in children from 6 to 18 months of age in all the overpopulated and impoverished areas of the world. -children in impoverished nations simply do not have enough to eat and subsist on diluted cereal drinks that supply scant energy and protein of low quality; such food can barely sustain life, much less support growth. -consequently, marasmic children look like little old peo- ple just skin and bones. -table 6-3 features of marasmus and kwashiorkor in children protein: amino acids 197 rice drinks are often sold as milk alternatives, but they fail to provide adequate protein, vita- mins, and minerals. -acute pem: protein-energy malnutrition caused by recent severe food restriction; characterized in children by thinness for height (wasting). -chronic pem: protein-energy malnutrition caused by long-term food deprivation; characterized in children by short height for age (stunting). -marasmus (ma-raz-mus): a form of pem that results from a severe deprivation, or impaired absorption, of energy, protein, vitamins, and minerals. -separating pem into two classifications oversimplifies the condition, but at the extremes, marasmus and kwashiorkor exhibit marked differences. -marasmus- kwashiorkor mix presents symptoms common to both marasmus and kwashiorkor. -in all cases, children are likely to develop diarrhea, infections, and multiple nutrient deficiencies. -marasmus infancy (less than 2 yr) severe deprivation, or impaired absorption, of protein, energy, vitamins, and minerals develops slowly; chronic pem severe weight loss kwashiorkor older infants and young children (1 to 3 yr) inadequate protein intake or, more commonly, infections rapid onset; acute pem some weight loss severe muscle wasting, with no body fat some muscle wasting, with retention of some body fat growth: <60% weight-for-age no detectable edema no fatty liver anxiety, apathy good appetite possible growth: 60 to 80% weight-for-age edema enlarged fatty liver apathy, misery, irritability, sadness loss of appetite hair is sparse, thin, and dry; easily pulled out hair is dry and brittle; easily pulled out; changes color; becomes straight skin is dry, thin, and easily wrinkles skin develops lesions 198 chapter 6 s o t o h p d l r o w e d i w / p a without adequate nutrition, muscles, including the heart, waste and weaken. -because the brain normally grows to almost its full adult size within the first two years of life, marasmus impairs brain development and learning ability. -reduced synthesis of key hormones slows metabolism and lowers body temperature. -there is little or no fat under the skin to insulate against cold. -hospital workers find that children with marasmus need to be clothed, covered, and kept warm. -because these children often suffer delays in their mental and behavioral development, they also need loving care, a stimulating environment, and parental attention. -the starving child faces this threat to life by engaging in as little activity as pos- sible not even crying for food. -the body musters all its forces to meet the crisis, so it cuts down on any expenditure of energy not needed for the functioning of the heart, lungs, and brain. -growth ceases; the child is no larger at age four than at age two. -enzymes are in short supply and the gi tract lining deteriorates. -conse- quently, the child can t digest and absorb what little food is eaten. -kwashiorkor kwashiorkor typically reflects a sudden and recent deprivation of food (acute pem). -kwashiorkor is a ghanaian word that refers to the birth posi- tion of a child and is used to describe the illness a child develops when the next child is born. -when a mother who has been nursing her first child bears a second child, she weans the first child and puts the second one on the breast. -the first child, suddenly switched from nutrient-dense, protein-rich breast milk to a starchy, protein-poor cereal, soon begins to sicken and die. -kwashiorkor typically sets in between 18 months and two years. -kwashiorkor usually develops rapidly as a result of protein deficiency or, more commonly, is precipitated by an illness such as measles or other infection. -other factors, such as aflatoxins (a contaminant sometimes found in moldy grains), may also contribute to the development of, or symptoms that accompany, kwashiorkor.6 the loss of weight and body fat is usually not as severe in kwashiorkor as in marasmus, but some muscle wasting may occur. -proteins and hormones that pre- viously maintained fluid balance diminish, and fluid leaks into the interstitial spaces. -the child s limbs and abdomen become swollen with edema, a distinguish- ing feature of kwashiorkor. -a fatty liver develops due to a lack of the protein car- riers that transport fat out of the liver. -the fatty liver lacks enzymes to clear metabolic toxins from the body, so their harmful effects are prolonged. -inflamma- tion in response to these toxins and to infections further contributes to the edema that accompanies kwashiorkor. -without sufficient tyrosine to make melanin, the child s hair loses its color, and inadequate protein synthesis leaves the skin patchy and scaly, often with sores that fail to heal. -the lack of proteins to carry or store iron leaves iron free. -unbound iron is common in children with kwashiorkor and may contribute to their illnesses and deaths by promoting bacterial growth and free-radical damage. -(free-radical damage is discussed fully in highlight 11.) -marasmus-kwashiorkor mix the combination of marasmus and kwashiorkor is characterized by the edema of kwashiorkor with the wasting of marasmus. -most often, the child suffers the effects of both malnutrition and infections. -some re- searchers believe that kwashiorkor and marasmus are two stages of the same dis- ease. -they point out that kwashiorkor and marasmus often exist side by side in the same community where children consume the same diet. -they note that a child who has marasmus can later develop kwashiorkor. -some research indicates that marasmus represents the body s adaptation to starvation and that kwashiorkor de- velops when adaptation fails. -infections in pem, antibodies to fight off invading bacteria are degraded to pro- vide amino acids for other uses, leaving the malnourished child vulnerable to in- fections. -blood proteins, including hemoglobin, are no longer synthesized, so the child becomes anemic and weak. -dysentery, an infection of the digestive tract, causes diarrhea, further depleting the body of nutrients and fluids. -in the maras- mic child, once infection sets in, kwashiorkor often follows, and the immune re- sponse weakens further.7 the extreme loss of muscle and fat characteris- tic of marasmus is apparent in this child s matchstick arms. -for this reason, kwashiorkor is sometimes referred to as wet pem and marasmus as dry pem. -kwashiorkor (kwash-ee-or-core, kwash-ee- or-core): a form of pem that results either from inadequate protein intake or, more commonly, from infections. -dysentery (diss-en-terry): an infection of the digestive tract that causes diarrhea. -protein: amino acids 199 s i b r o c / s r e d n u o s . -a l u a p the edema characteristic of kwashiorkor is apparent in this child s swollen belly. -malnour- ished children commonly have an enlarged abdomen from parasites as well. -the combination of infections, fever, fluid imbalances, and anemia often leads to heart failure and occasionally sudden death. -infections combined with malnu- trition are responsible for two-thirds of the deaths of young children in developing countries. -measles, which might make a healthy child sick for a week or two, kills a child with pem within two or three days. -rehabilitation if caught in time, the life of a starving child may be saved with nu- trition intervention. -in severe cases, diarrhea will have incurred dramatic fluid and mineral losses that need to be replaced during the first 24 to 48 hours to help raise the blood pressure and strengthen the heartbeat. -after that, protein and food energy may be given in small quantities, with intakes gradually increased as tolerated. -se- verely malnourished people, especially those with edema, recover better with an ini- tial diet that is relatively low in protein (10 percent kcalories from protein). -experts assure us that we possess the knowledge, technology, and resources to end hunger. -programs that tailor interventions to the local people and involve them in the process of identifying problems and devising solutions have the most success. -to win the war on hunger, those who have the food, technology, and re- sources must make fighting hunger a priority (see chapter 20 for more on hunger). -health effects of protein while many of the world s people struggle to obtain enough food energy and pro- tein, in developed countries both are so abundant that problems of excess are seen. -overconsumption of protein offers no benefits and may pose health risks. -high-protein diets have been implicated in several chronic diseases, including heart disease, cancer, osteoporosis, obesity, and kidney stones, but evidence is in- sufficient to establish an upper level.8 researchers attempting to clarify the relationships between excess protein and chronic diseases face several obstacles. -population studies have difficulty determin- ing whether diseases correlate with animal proteins or with their accompanying saturated fats, for example. -studies that rely on data from vegetarians must sort out the many lifestyle factors, in addition to a no-meat diet, that might explain relationships between protein and health. -heart disease a high-protein diet may contribute to the progression of heart dis- ease. -as chapter 5 mentioned, foods rich in animal protein also tend to be rich in saturated fats. -consequently, it is not surprising to find a correlation between ani- mal-protein intake (red meats and dairy products) and heart disease.9 on the other hand, substituting vegetable protein for animal protein improves blood lipids and decreases heart disease mortality.10 research suggests that elevated levels of the amino acid homocysteine may be an independent risk factor for heart disease, heart attacks, and sudden death in patients with heart disease.11 researchers do not yet fully understand the many factors including a high protein diet that can raise homocysteine in the blood or whether elevated levels are a cause or an effect of heart disease.12 until they can determine the exact role homocysteine plays in heart disease, researchers are fol- lowing several leads in pursuit of the answers. -coffee s role in heart disease has been controversial, but research suggests it is among the most influential factors in raising homocysteine, which may explain some of the adverse health effects of heavy consumption.13 elevated homocysteine levels are among the many adverse health consequences of smoking cigarettes and drinking alcohol as well.14 homo- cysteine is also elevated with inadequate intakes of b vitamins and can usually be lowered with fortified foods or supplements of vitamin b12, vitamin b6, and fo- late.15 lowering homocysteine, however, may not help in preventing heart at- tacks.16 supplements of the b vitamins do not always benefit those with heart disease and in fact, may actually increase the risks.17 in contrast to homocysteine, the amino acid arginine may help protect against heart disease by lowering blood pressure and homocysteine levels.18 additional research is needed to confirm the benefits of arginine.19 in the meantime, it is unwise 200 chapter 6 for consumers to use supplements of arginine, or any other amino acid for that matter (as pp. -202 203 explain). -physicians, however, may find it beneficial to add arginine supplements to their heart patients treatment plan.20 cancer as in heart disease, the effects of protein and fats on cancers cannot be eas- ily separated. -population studies suggest a correlation between high intakes of ani- mal proteins and some types of cancer (notably, cancer of the colon, breast, kidneys, pancreas, and prostate). -adult bone loss (osteoporosis) chapter 12 presents calcium metabolism, and highlight 12 elaborates on the main factors that influence osteoporosis. -this section briefly describes the relationships between protein intake and bone loss. -when pro- tein intake is high, calcium excretion increases. -whether excess protein depletes the bones of their chief mineral may depend upon the ratio of calcium intake to protein intake. -after all, bones need both protein and calcium. -an ideal ratio has not been de- termined, but a young woman whose intake meets recommendations for both nutri- ents has a calcium-to-protein ratio of more than 20 to 1 (milligrams to grams), which probably provides adequate protection for the bones. -for most women in the united states, however, average calcium intakes are lower and protein intakes are higher, yielding a 9-to-1 ratio, which may produce calcium losses significant enough to com- promise bone health. -in other words, the problem may reflect too little calcium, not too much protein.21 in establishing recommendations, the dri committee considered protein s effect on calcium metabolism and bone health, but it did not find sufficient evidence to warrant an adjustment for calcium or an upper level for protein.22 some (but not all) research suggests that animal protein may be more detrimen- tal to calcium metabolism and bone health than vegetable protein.23 a review of the topic, however, concludes that excess protein whether from animal or veg- etable sources increases calcium excretion and, perhaps more importantly, that the other nutrients in the protein source may be equally, if not more, responsible for the effects on bone health.24 inadequate intakes of protein may also compromise bone health.25 osteoporo- sis is particularly common in elderly women and in adolescents with anorexia ner- vosa groups who typically receive less protein than they need. -for these people, increasing protein intake may be just what they need to protect their bones.26 weight control dietary protein may play a role in increasing body weight.27 pro- tein-rich foods are often fat-rich foods that contribute to weight gain with its accom- panying health risks. -as highlight 9 explains, weight-loss gimmicks that encourage a high-protein, low-carbohydrate diet may be temporarily effective, but only be- cause they are low-kcalorie diets. -diets that provide adequate protein, moderate fat, and sufficient energy from carbohydrates can better support weight loss and good health. -including protein at each meal may help with weight loss by providing sati- ety.28 selecting too many protein-rich foods, such as meat and milk, may crowd out fruits, vegetables, and whole grains, making the diet inadequate in other nutrients. -kidney disease excretion of the end products of protein metabolism depends, in part, on an adequate fluid intake and healthy kidneys. -a high protein intake increases the work of the kidneys, but does not appear to diminish kidney function or cause kidney disease.29 restricting dietary protein, however, may help to slow the progression of kidney disease and limit the formation of kidney stones in peo- ple who have these conditions. -in summary protein deficiencies arise from both energy-poor and protein-poor diets and lead to the devastating diseases of marasmus and kwashiorkor. -together, these diseases are known as pem (protein-energy malnutrition), a major form of malnutrition causing death in children worldwide. -excesses of protein offer no advantage; in fact, overconsumption of protein-rich foods may incur health problems as well. -recommended intakes of protein as mentioned earlier, the body continuously breaks down and loses some protein and cannot store amino acids. -to replace protein, the body needs dietary protein for two reasons. -first, food protein is the only source of the essential amino acids, and second, it is the only practical source of nitrogen with which to build the nonessen- tial amino acids and other nitrogen-containing compounds the body needs. -given recommendations that people s fat intakes should contribute 20 to 35 percent of total food energy and carbohydrate intakes should contribute 45 to 65 percent, that leaves 10 to 35 percent for protein. -in a 2000-kcalorie diet, that repre- sents 200 to 700 kcalories from protein, or 50 to 175 grams. -average intakes in the united states and canada fall within this range. -protein rda the protein rda for adults is 0.8 grams per kilogram of healthy body weight per day. -for infants and children, the rda is slightly higher. -the table on the inside front cover lists the rda for males and females at various ages in two ways grams per day based on reference body weights and grams per kilo- gram body weight per day. -the rda generously covers the needs for replacing worn-out tissue, so it in- creases for larger people; it also covers the needs for building new tissue during growth, so it increases for infants, children, and pregnant women. -the protein rda is the same for athletes as for others, although some fitness authorities recommend a slightly higher intake, as chapter 14 explains.30 the accompanying how to ex- plains how to calculate your rda for protein. -in setting the rda, the dri committee assumes that people are healthy and do not have unusual metabolic needs for protein, that the protein eaten will be of mixed quality (from both high- and low-quality sources), and that the body will use the protein efficiently. -in addition, the committee assumes that the protein is consumed along with sufficient carbohydrate and fat to provide adequate energy and that other nutrients in the diet are adequate. -adequate energy note the qualification adequate energy in the preceding statement, and consider what happens if energy intake falls short of needs. -an in- take of 50 grams of protein provides 200 kcalories, which represents 10 percent of the total energy from protein, if the person receives 2000 kcalories a day. -but if the person cuts energy intake drastically to, say, 800 kcalories a day then an intake of 200 kcalories from protein is suddenly 25 percent of the total; yet it s still the same amount of protein (number of grams). -the protein intake is reasonable, but the en- ergy intake is not. -the low energy intake forces the body to use the protein to meet energy needs rather than to replace lost body protein. -similarly, if the person s en- ergy intake is high say, 4000 kcalories the 50-gram protein intake represents only 5 percent of the total; yet it still is a reasonable protein intake. -again, the energy in- take is unreasonable for most people, but in this case, it permits the protein to be used to meet the body s needs. -be careful when judging protein (or carbohydrate or fat) intake as a percentage of energy. -always ascertain the number of grams as well, and compare it with the rda or another standard stated in grams. -a recommendation stated as a percent- age of energy intake is useful only if the energy intake is within reason. -protein in abundance most people in the united states and canada receive more protein than they need. -even athletes in training typically don t need to in- crease their protein intakes because the additional foods they eat to meet their high energy needs deliver protein as well. -(chapter 14 provides full details on the energy and protein needs of athletes.) -that protein intake is high is not surprising consider- ing the abundance of food eaten and the central role meats hold in the north amer- ican diet. -a single ounce of meat (or 1/2 cup legumes) delivers about 7 grams of protein, so 8 ounces of meat alone supplies more than the rda for an average-size person. -besides meat, well-fed people eat many other nutritious foods, many of which also provide protein. -a cup of milk provides 8 grams of protein. -grains and protein: amino acids 201 how to calculate recommended protein intakes to figure your protein rda: look up the healthy weight for a person of your height (inside back cover). -if your present weight falls within that range, use it for the following calculations. -if your pres- ent weight falls outside the range, use the midpoint of the healthy weight range as your reference weight. -convert pounds to kilograms, if necessary (pounds divided by 2.2 equals kilograms). -multiply kilograms by 0.8 to get your rda in grams per day. -(older teens 14 to 18 years old, multiply by 0.85.) -example: weight (cid:4) 150 lb 150 lb (cid:5) 2.2 lb/kg (cid:4) 68 kg (rounded off) 68 kg (cid:6) 0.8 g/kg (cid:4) 54 g protein (rounded off) to calculate recommended protein intakes, log on to www.thomsonedu.com/thomsonnow, go to chapter 6, then go to how to. -rda for protein: 0.8 g/kg/day 10 to 35% of energy intake . -c n i , s o i d u t s l a r a o p for many people, this 5-ounce steak provides almost all of the meat and much of the pro- tein recommended for a day s intake. -202 chapter 6 vegetables provide small amounts of protein, but they can add up to significant quantities; fruits and fats provide no protein. -to illustrate how easy it is to overconsume protein, consider the amounts recom- mended by the usda food guide for a 2000-kcalorie diet. -six ounces of grains pro- vide about 18 grams of protein; 21/2 cups of vegetables deliver about 10 grams; 3 cups of milk offer 24 grams; and 51/2 ounces of meat supply 38 grams. -this totals 90 grams of protein higher than recommendations for most people and yet still lower than the average intake of people in the united states. -. -c n i s o i d u t s a r a l o p people in the united states and canada get more protein than they need. -if they have an adequate food intake, they have a more-than-adequate protein intake. -the key diet-planning principle to emphasize for protein is moderation. -even though most people receive plenty of protein, some feel compelled to take supple- ments as well, as the next section describes. -in summary the optimal diet is adequate in energy from carbohydrate and fat and deliv- ers 0.8 grams of protein per kilogram of healthy body weight each day. -u.s. and canadian diets are typically more than adequate in this respect. -protein and amino acid supplements websites, health-food stores, and popular magazine articles advertise a wide variety of protein supplements, and people take these supplements for many different rea- sons. -athletes take protein powders to build muscle. -dieters take them to spare their bodies protein while losing weight. -women take them to strengthen their finger- nails. -people take individual amino acids, too to cure herpes, to make themselves sleep better, to lose weight, and to relieve pain and depression. -* like many other magic solutions to health problems, protein and amino acid supplements don t work these miracles. -furthermore, they may be harmful. -protein powders because the body builds muscle protein from amino acids, many athletes take protein powders with the false hope of stimulating muscle growth. -mus- cle work builds muscle; protein supplements do not, and athletes do not need them. -taking protein supplements does not improve athletic performance.31 (highlight 14 presents more information on other supplements athletes commonly use.) -protein powders can supply amino acids to the body, but nature s protein sources lean meat, milk, eggs, and legumes supply all these amino acids and more. -whey protein appears to be particularly popular among athletes hoping to achieve greater muscle gains. -a waste product of cheese manufacturing, whey pro- tein is a common ingredient in many low-cost protein powders. -when combined with strength training, whey supplements may increase protein synthesis slightly, but they do not seem to enhance athletic performance.32 to build stronger muscles, athletes need to eat food with adequate energy and protein to support the weight- training work that does increase muscle mass. -those who still think they need more whey should pour a glass of milk; one cup provides 1.5 grams of whey. -purified protein preparations contain none of the other nutrients needed to sup- port the building of muscle, and the protein they supply is not needed by athletes who eat food. -it is excess protein, and the body dismantles it and uses it for energy or stores it as body fat. -the deamination of excess amino acids places an extra bur- den on the kidneys to excrete unused nitrogen. -amino acid supplements single amino acids do not occur naturally in foods and offer no benefit to the body; in fact, they may be harmful. -the body was not de- signed to handle the high concentrations and unusual combinations of amino acids * canada only allows single amino acid supplements to be sold as drugs or used as food additives. -vegetarians obtain their protein from whole grains, legumes, nuts, vegetables, and, in some cases, eggs and milk products. -use of amino acids as dietary supplements is inappropriate, especially for: all women of childbearing age pregnant or lactating women infants, children, and adolescents elderly people people with inborn errors of metabolism that affect their bodies handling of amino acids smokers people on low-protein diets people with chronic or acute mental or physical illnesses who take amino acids without medical supervision whey protein: a by-product of cheese production; falsely promoted as increasing muscle mass. -whey is the watery part of milk that separates from the curds. -protein: amino acids 203 the branched-chain amino acids are leucine, isoleucine, and valine. -found in supplements. -an excess of one amino acid can create such a demand for a carrier that it limits the absorption of another amino acid, presenting the possibility of a deficiency. -those amino acids winning the competition enter in excess, creating the possibility of toxicity. -toxicity of single amino acids in animal studies raises con- cerns about their use in human beings. -anyone considering taking amino acid sup- plements should check with a registered dietitian or physician first. -most healthy athletes eating well-balanced diets do not need amino acid sup- plements. -advertisers point to research that identifies the branched-chain amino acids as the main ones used as fuel by exercising muscles. -what the ads leave out is that compared to glucose and fatty acids, branched-chain amino acids provide very little fuel and that ordinary foods provide them in abundance anyway. -large doses of branched-chain amino acids can raise plasma ammonia concentrations, which can be toxic to the brain. -branched-chain amino acid sup- plements may be useful in conditions such as advanced liver failure, but other- wise, they are not routinely recommended.33 in two cases, recommendations for single amino acid supplements have led to widespread public use lysine to prevent or relieve the infections that cause herpes cold sores on the mouth or genital organs, and tryptophan to relieve pain, depres- sion, and insomnia. -in both cases, enthusiastic popular reports preceded careful scientific experiments and health recommendations. -research is insuffiencient to determine whether lysine suppresses herpes infections, but it appears safe (up to 3 grams per day) when taken in divided doses with meals.34 tryptophan may be effective with respect to pain and sleep, but its use for these purposes is experimental. -about 20 years ago, more than 1500 people who elected to take tryptophan supplements developed a rare blood disorder known as eosinophilia-myalgia syndrome (ems). -ems is characterized by severe muscle and joint pain, extremely high fever, and, in over three dozen cases, death. -treatment for ems usually involves physical therapy and low doses of corticosteroids to relieve symptoms temporarily. -the food and drug administration implicated impurities in the supplements, issued a recall of all products containing manufactured trypto- phan, and warned that high-dose supplements of tryptophan might provoke ems even in the absence of impurities. -in summary normal, healthy people never need protein or amino acid supplements. -it is safest to obtain lysine, tryptophan, and all other amino acids from protein-rich foods, eaten with abundant carbohydrate and some fat to facilitate their use in the body. -with all that we know about science, it is hard to improve on nature. -nutrition portfolio www.thomsonedu.com/thomsonnow foods that derive from animals meats, fish, poultry, eggs, and milk products provide plenty of protein but are often accompanied by fat. -those that derive from plants whole grains, vegetables, and legumes may provide less protein but also less fat. -calculate your daily protein needs and compare them with your protein intake. -consider whether you receive enough, but not too much, protein daily. -describe your dietary sources of proteins and whether you use mostly plant-based or animal-based protein foods in your diet. -debate the risks and benefits of taking protein or amino acid supplements. -branched-chain amino acids: the essential amino acids leucine, isoleucine, and valine, which are present in large amounts in skeletal muscle tissue; falsely promoted as fuel for exercising muscles. -204 chapter 6 nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 6, then to nutrition on the net. -learn more about sickle-cell anemia from the national heart, lung, and blood institute or the sickle cell disease association of america: www.nhlbi.nih.gov or www.sicklecelldisease.org learn more about protein-energy malnutrition and world hunger from the world health organization nutrition programme or the national institute of child health and human development: www.who.int/nut or www.nichd.nih.gov chapter 20 offers many more websites on malnutrition and world hunger. -nutrition calculations for additional practice, log on to www.thomsonedu.com/thomsonnow. -go to chapter 6, then to nutrition calculations. -these problems will give you practice in doing simple nutrition-related calculations using hypothetical situations (see p. 206 for answers). -once you have mastered these examples, you will be prepared to examine your own protein needs. -be sure to show your calculations for each problem. -1. compute recommended protein intakes for people of different sizes. -refer to the how to on p. 201 and compute the protein recommendation for the following people. -the intake for a woman who weighs 144 pounds is computed for you as an example. -144 lb (cid:5) 2.2 lb/kg (cid:4) 65 kg 0.8 g/kg (cid:6) 65 kg (cid:4) 52 g protein per day a. a woman who weighs 116 pounds b. a man (18 years) who weighs 180 pounds study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. how does the chemical structure of proteins differ from the structures of carbohydrates and fats? -(pp. -181 184) 2. describe the structure of amino acids, and explain how their sequence in proteins affects the proteins shapes. -what are essential amino acids? -(pp. -181 184) 3. describe protein digestion and absorption. -(pp. -185 186) 4. describe protein synthesis. -(pp. -187 189) 5. describe some of the roles proteins play in the human body. -(pp. -189 192) 6. what are enzymes? -what roles do they play in chemical reactions? -describe the differences between enzymes and hormones. -(p. 190) 2. the chapter warns that recommendations based on percentage of energy intake are not always appropriate. -consider a woman 26 years old who weighs 165 pounds. -her diet provides 1500 kcalories/day with 50 grams carbohydrate and 100 grams fat. -a. what is this woman s protein intake? -show your calculations. -b. is her protein intake appropriate? -justify your answer. -c. are her carbohydrate and fat intakes appropriate? -justify your answer. -this exercise should help you develop a perspective on protein recommendations. -7. how does the body use amino acids? -what is deamina- tion? -define nitrogen balance. -what conditions are associated with zero, positive, and negative balance? -(pp. -193 194) 8. what factors affect the quality of dietary protein? -what is a high-quality protein? -(pp. -195 196) 9. how can vegetarians meet their protein needs without eating meat? -(pp. -195 196) 10. what are the health consequences of ingesting inade- quate protein and energy? -describe marasmus and kwa- shiorkor. -how can the two conditions be distinguished, and in what ways do they overlap? -(pp. -196 199) 11. how might protein excess, or the type of protein eaten, influence health? -(pp. -199 200) 12. what factors are considered in establishing recommended protein intakes? -(pp. -201 202) 13. what are the benefits and risks of taking protein and amino acid supplements? -(p. 202 203) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 206. -1. which part of its chemical structure differentiates one amino acid from another? -a. its side group b. its acid group c. its amino group d. its double bonds 2. isoleucine, leucine, and lysine are: a. proteases. -b. polypeptides. -c. essential amino acids. -d. complementary proteins. -3. in the stomach, hydrochloric acid: a. denatures proteins and activates pepsin. -b. hydrolyzes proteins and denatures pepsin. -c. emulsifies proteins and releases peptidase. -d. condenses proteins and facilitates digestion. -4. proteins that facilitate chemical reactions are: a. buffers. -b. enzymes. -c. hormones. -d. antigens. -5. if an essential amino acid that is needed to make a protein is unavailable, the cells must: a. deaminate another amino acid. -b. substitute a similar amino acid. -c. break down proteins to obtain it. -d. synthesize the amino acid from glucose and nitrogen. -protein: amino acids 205 6. protein turnover describes the amount of protein: a. found in foods and the body. -b. absorbed from the diet. -c. synthesized and degraded. -d. used to make glucose. -7. which of the following foods provides the highest qual- ity protein? -a. egg b. corn c. gelatin d. whole grains 8. marasmus develops from: a. too much fat clogging the liver. -b. megadoses of amino acid supplements. -c. inadequate protein and energy intake. -d. excessive fluid intake causing edema. -9. the protein rda for a healthy adult who weighs 180 pounds is: a. -50 milligrams/day. -b. -65 grams/day. -c. 180 grams/day. -d. 2000 milligrams/day. -10. which of these foods has the least protein per 1/2 cup? -a. rice b. broccoli c. pinto beans d. orange juice references 1. m. s. buchowski and coauthors, equation to estimate resting energy expenditure in adolescents with sickle cell anemia, ameri- can journal of clinical nutrition 76 (2002): 1335-1344; committee on genetics, health supervision for children with sickle cell disease, pediatrics 109 (2002): 526-535. -2. j. m. ordovas and d. corella, nutritional genomics, annual review of genomics and human genetics 5 (2004): 71-118. -3. w. m. rand, p. l. pellett, and v. r. young, meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults, american journal of clinical nutrition 77 (2003): 109-127. -4. position of the american dietetic associa- tion and dietitians of canada: vegetarian diets, journal of the american dietetic associ- ation 103 (2003): 748-765. -5. data from www.unicef.org, posted april 2005 and may 2006. -6. m. krawinkel, kwashiorkor is still not fully understood, bulletin of the world health organization 81 (2003): 910-911. -7. m. reid and coauthors, the acute-phase protein response to infection in edematous and nonedematous protein-energy malnu- trition, american journal of clinical nutrition 76 (2002): 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hypercholesterolemic subjects, american journal of clinical nutrition 76 (2002): 78-84. -11. m. haim and coauthors, serum homocys- teine and long-term risk of myocardial infarction and sudden death in patients with coronary heart disease, cardiology 107 (2006): 52-56; m. b. kazemi and coauthors, homocysteine level and coronary artery disease, angiology 57 (2006): 9-14; d. s. wald, m. law, and j. k. morris, homocys- teine and cardiovascular disease: evidence on causality from a meta-analysis, british medical journal 325 (2002): 1202-1217; the homocysteine studies collaboration, ho- mocysteine and risk of ischemic heart disease and stroke, journal of the american medical association 288 (2002): 2015-2022. -12. j. selhub, the many facets of hyperhomo- cysteinemia: studies from the framingham cohorts, journal of nutrition 136 (2006): 1726s-1730s; p. verhoef and coauthors, a high-protein diet increases postprandial but not fasting plasma total homocysteine concentrations: a dietary controlled, crossover trial in healthy volunteers, ameri- can journal of clinical nutrition 82 (2005): 553-558. -13. s. e. chiuve and coauthors, alcohol intake and methylenetetrahydrofolate reductase polymorphism modify the relation of folate intake to plasma homocysteine, american journal of clinical nutrition 82 (2005): 155- 162; p. verhoef and coauthors, contribu- tion of caffeine to the homocysteine-raising effect of coffee: a randomized controlled trial in humans, american journal of clinical nutrition 76 (2002): 1244-1248. -14. j. a. troughton and coauthors, homocys- teine and coronary heart disease risk in the prime study, atherosclerosis (2006); s. e. chiuve and coauthors, alcohol intake and methylenetetrahydrofolate reductase poly- morphism modify the relation of folate intake to plasma homocysteine, american journal of clinical nutrition 82 (2005): 155-162. -15. d. genser and coauthors, homocysteine, folate and vitamin b(12) in patients with coronary heart disease, annals of 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b-vitamin treatment trialists collabora- tion, homocysteine-lowering trials for prevention of cardiovascular events: a review of the design and power of the large randomized trials, american heart journal 151 (2006): 282-287. -17. e. lonn and coauthors, homocysteine lowering with folic acid and b vitamins in vascular disease, new england journal of medicine 354 (2006): 1567-1577; k. h. bonaa and coauthors, homocysteine lowering and cardiovascular events after acute myocardial infarction, new england journal of medicine 354 (2006): 1578-1588; g. schnyder and coauthors, effect of homocysteine-lowering therapy with folic acid, vitamin b12, and vitamin b6 on clinical outcome after percu- taneous coronary intervention-the swiss heart study: a randomized controlled trial, journal of the american medical association 288 (2002): 973-979; b. j. venn and coau- thors, dietary counseling to increase natural folate intake: a randomized, placebo-con- trolled trial in free-living subjects to assess effects on serum folate and plasma total homocysteine, american journal of clinical nutrition 76 (2002): 758-765. -18. s. g. west and coauthors, oral l-arginine improves hemodynamic responses to stress and reduces plasma homocysteine in hyper- cholesterolemic men, journal of nutrition 135 (2005): 212-217. -19. n. gokce, l-arginine and hypertension, journal of nutrition 134 (2004): 2807s-2811s. -20. b. s. kendler, supplemental conditionally essential nutrients in cardiovascular disease therapy, journal of cardiovascular nursing 21 (2006): 9-16. -21. b. dawson-hughes, interaction of dietary calcium and protein in bone health in humans, journal of nutrition 133 (2003): 852s-854s. -22. committee on dietary reference intakes, 2002/2005, p. 841; committee on dietary reference intakes, dietary reference intakes for calcium, phosphorus, magnesium, vitamin d, and fluoride (washington, d.c.: national academy press, 1997), pp. -75-76. -23. j. p. bonjour, dietary protein: an essential nutrient for bone health, journal of the american college of nutrition 24 (2005): 526s- 536s; c. weikert and coauthors, the rela- tion between dietary protein, calcium and bone health in women: results from the epic-potsdam cohort, annals of nutrition & metabolism 49 (2005): 312-318. -24. l. k. massey, dietary animal and plant protein and human bone health: a whole foods approach, journal of nutrition 133 (2003): 862s-865s. -25. f. ginty, dietary protein and bone health, the proceedings of the nutrition society 62 (2003): 867-876; j. e. kerstetter, k. o. o brien, and k. l. insogna, low protein intake: the impact on calcuim and bone homeostasis in humans, journal of nutrition 133 (2003): 855s-861s. -26. a. devine and coauthors, protein consump- tion is an important predictor of lower limb bone mass in elderly women, american journal of clinical nutrition 81 (2005): 1423- 1428; j. bell and s. j. whiting, elderly women need dietary protein to maintain bone mass, nutrition reviews 60 (2002): 337- 341; m. t. munoz and j. argente, anorexia nervosa in female adolescents: endocrine and bone mineral density disturbances, european journal of endocrinology 147 (2002): 275-286. -27. a. trichopoulou and coauthors, lipid, protein and carbohydrate intake in relation to body mass index, european journal of clinical nutrition 56 (2002): 37-43. -28. a. astrup, the satiating power of protein a key to obesity prevention? -american journal of clinical nutrition 82 (2005): 1-2; d. s. weigle and coauthors, a high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations, american journal of clinical nutrition 82 (2005): 41-48. -29. e. l. knight and coauthors, the impact of protein intake on renal function decline in women with normal renal function or mild renal insufficiency, annals of internal medi- cine 138 (2003): 460-467. -30. position of the american dietetic associa- tion, dietitians of canada, and the ameri- can college of sports nutrition, nutrition and athletic performance, journal of the american dietetic association 100 (2000): 1543-1556. -31. l. l. andersen and coauthors, the effect of resistance training combined with timed ingestion of protein on muscle fiber size and muscle strength, metabolism: clinical and experimental 54 (2005): 151-156. -32. k. d. tipton, ingestion of casein and whey proteins result in muscle anabolism after resistance exercise, medicine and science in sports and exercise 36 (2004): 2073-2081. -33. r. mascarenhas and s. mobarhan, new support for branched-chain amino acid supplementation in advanced hepatic failure, nutrition reviews 62 (2004): 33-38. -34. m. m. perfect and coauthors, use of com- plementary and alternative medicine for the treatment of genital herpes, herpes 12 (2005): 38-41. answers nutrition calculations 1. a. -116 lb (cid:5) 2.2 lb/kg (cid:4) 53 kg 0.8 g/kg (cid:6) 53 kg (cid:4) 42 g protein per day b. -180 lb (cid:5) 2.2 lb/kg (cid:4) 82 kg he is 18 years old, so use 0.85 g/kg. -0.85 g/kg (cid:6) 82 kg (cid:4) 70 g protein per day 2. a. -50 g carbohydrate (cid:6) 4 kcal/g (cid:4) 200 kcal from carbohydrate 100 g fat (cid:6) 9 kcal/g (cid:4) 900 kcal from fat 1500 kcal (cid:7) (200 (cid:8) 900 kcal) (cid:4) 400 kcal from protein 400 kcal (cid:5) 4 kcal/g (cid:4) 100 g protein is higher than her rda. -using the guideline that protein should contribute 10 to 35% of energy intake, her intake of 100 g protein on a 1500 kcal diet falls within the suggested range (400 kcal protein (cid:5) 1500 total kcal (cid:4) 27%). -c. using the guideline that carbohydrate should contribute 45 to 65% and fat should contribute 20 to 35% of energy intake, her intake of 50 g carbohydrate is low (200 kcal car- bohydrate (cid:5) 1500 total kcal (cid:4) 13%), and her intake of 100 g fat is high (900 kcal fat (cid:5) 1500 total kcal (cid:4) 60%). -study questions (multiple choice) b. using the rda guideline of 0.8 g/kg, an appropriate protein intake for this woman would be 60 g protein/day (165 lb (cid:5) 2.2 lb/kg (cid:4) 75 kg; 0.8 g/kg (cid:6) 75 (cid:4) 60 g/day). -her intake 1. a 8. c 2. c 9. b 3. a 4. b 5. c 6. c 7. a 10. d highlight 6 nutritional genomics imagine this scenario: a physician scrapes a sample of cells from inside your cheek and submits it to a genomics lab. -the lab re- turns a report based on your genetic profile that reveals which diseases you are most likely to develop and makes recommenda- tions for specific diet and lifestyle changes that can help you maintain good health. -you may also be given a prescription for a dietary supplement that will best meet your personal nutrient requirements. -such a sce- nario may one day become reality as scientists uncover the ge- netic relationships between diet and disease. -(until then, however, consumers need to know that current genetic test kits commonly available on the internet are unproven and quite likely fraudulent.) -how nutrients influence gene activity and how genes influ- ence the activities of nutrients is the focus of a new field of study called nutritional genomics (see the accompanying glossary). -unlike sciences in the 20th century, nutritional genomics takes a comprehensive approach in analyzing information from several fields of study, providing an integrated understanding of the find- ings.1 consider how multiple disciplines contributed to our un- derstanding of vitamin a over the past several decades, for example. -biochemistry revealed vitamin a s three chemical struc- tures. -immunology identified the anti-infective properties of one m d e t i i l n u s l a u s i v / u v of these structures while physiology focused on another structure and it s role in vision. -epidemiology has reported improvements in the death rates and vision of malnour- ished children given vitamin a supple- ments, and biology has explored how such effects might be possible. -the process was slow as researchers collected information on one gene, one action, and one nutrient at a time. -today s re- search in nutritional genomics involves all of the sciences, coor- dinating their interactions among several genes, actions, and nutrients in rel- atively little time. -as a result, nutrition knowledge is growing at an incredibly fast pace. -findings, and explaining their multiple e c n e i c s the recent surge in genomics research grew from the human genome project, an international effort by industry and govern- ment scientists to identify and describe all of the genes in the hu- man genome that is, all the genetic information contained within a person s cells. -completed in 2003, this project developed many of the research technologies needed to study genes and ge- netic variation. -scientists are now working to identify the individual proteins made by the genes, the genes associated with diseases, and the dietary and lifestyle choices that most influence the expres- sion of those genes. -such information will have major implications for society in general, and for health care in particular.2 g lossary chromosomes: structures within the nucleus of a cell made of dna and associated proteins. -human beings have 46 chromosomes in 23 pairs. -each chromosome has many genes. -dna (deoxyribonucleic acid): the double helix molecules of which genes are made. -epigenetics: the study of heritable changes in gene function that occur without a change in the dna sequence. -gene expression: the process by which a cell converts the genetic code into rna and protein. -genes: sections of chromosomes that contain the instructions needed to make one or more proteins. -genetics: the study of genes and inheritance. -genomics: the study of all the genes in an organism and their interactions with environmental factors. -human genome (gee-nome): the full complement of genetic material in the chromosomes of a person s cells. -microarray technology: research tools that analyze the expression of thousands of genes simultaneously and search for particular gene changes associated with a disease. -dna microarrays are also called dna chips. -mutations: a permanent change in the dna that can be inherited. -nucleotide bases: the nitrogen- containing building blocks of dna and rna cytosine (c), thymine (t), uracil (u), guanine (g), and adenine (a). -in dna, the base pairs are a t and c g and in rna, the base pairs are a u and c g. nucleotides: the subunits of dna and rna molecules, composed of a phosphate group, a 5- carbon sugar (deoxyribose for dna and ribose for rna), and a nitrogen-containing base. -nutritional genomics: the science of how food (and its components) interacts with the genome. -the study of how nutrients affect the activities of genes is called nutrigenomics. -the study of how genes affect the activities of nutrients is called nutrigenetics. -phenylketonuria (fen-il-key-toe- new-ree-ah) or pku: an inherited disorder characterized by failure to metabolize the amino acid phenylalanine to tyrosine. -rna (ribonucleic acid): a compound similar to dna, but rna is a single strand with a ribose sugar instead of a deoxyribose sugar and uracil instead of thymine as one of its bases. -207 208 highlight 6 a genomics primer figure h6-1 shows the relationships among the materials that comprise the genome. -as chapter 6 s discussion of protein syn- thesis pointed out, genetic information is encoded in dna mole- cules within the nucleus of cells. -the dna molecules and associated proteins are packed within 46 chromosomes. -the genes are segments of a dna strand that can eventually be trans- lated into one or more proteins. -the sequence of nucleotide bases within each gene determines the amino acid sequence of a particular protein. -scientists currently estimate that there are between 20,000 and 25,000 genes in the human genome. -as figure 6-7 (p. 188) explained, when cells make proteins, a dna sequence is used to make messenger rna. -the nucleotide sequence in messenger rna then determines the amino acid se- quence to make a protein. -this process from genetic information to protein synthesis is known as gene expression. -gene ex- pression can be determined by measuring the amounts of messen- ger rna in a tissue sample. -microarray technology (see photo on p. 207) allows researchers to detect messenger rna and ana- lyze the expression of thousands of genes simultaneously. -simply having a certain gene does not determine that its associ- ated trait will be expressed; the gene has to be activated. -(similarly, figure h6-1 the human genome owning lamps does not ensure you will have light in your home un- less you turn them on.) -nutrients are among many environmental factors that play key roles in either activating or silencing genes. -switching genes on and off does not change the dna itself, but it can have dramatic consequences for a person s health. -the area of study that examines how environmental factors in- fluence gene expression without changing the dna is known as epigenetics. -to turn genes on, enzymes attach proteins near the beginning of a gene. -if enzymes attach a methyl group (ch3) in- stead, the protein is blocked from binding to the gene and the gene remains switched off. -other factors influence gene expres- sion as well, but methyl groups are currently the most well under- stood. -they also are known to have dietary connections. -the accompanying photo of two mice illustrates epigenetics and how diet can influence genetic traits such as hair color and body weight. -both mice have a gene that tends to produce fat, yellow pups, but their mothers were given different diets. -the mother of the mouse on the right was given a dietary supplement containing the b vitamins folate and vitamin b12. -these nutrients silenced the gene for yellow and fat, resulting in brown pups with normal appetites. -as chapter 10 explains, one of the main roles of these b vitamins is to transfer methyl groups. -in the case of the supplemented mice, methyl groups migrated onto dna and shut off several genes, thus producing brown coats and protecting against the development of 1 nucleus cell 2 chromosome 3 dna gene t a g 5 c g 4 c g t a a c t a a t t a t a g c 1 2 3 4 the human genome is a complete set of genetic material organized into 46 chromosomes, located within the nucleus of a cell. -a chromosome is made of dna and associated proteins. -the double helical structure of a dna molecule is made up of two long chains of nucleotides. -each nucleotide is composed of a phosphate group, a 5-carbon sugar, and a base. -the sequence of nucleotide bases (c, g, a, t) determines the amino acid sequence of proteins. -these bases are connected by hydrogen bonding to form base pairs adenine (a) with thymine (t) and guanine (g) with cytosine (c). -5 a gene is a segment of dna that includes the information needed to synthesize one or more proteins. -adapted from a primer: from dna to life, human genome project, u.s. department of energy office of science; http://www.orn.gov/sci/techresources/human_genome/primer-pic.shtml. -d n a l r e t a w d n a e l t r i j nutritional genomics 209 diseases characterized by a single-gene disorder are geneti- cally predetermined, usually exert their effects early in life, and greatly affect those touched by them, but are relatively rare. -the cause and effect of single-gene disorders is clear those with the genetic defect get the disease and those without it don t. in con- trast, the more common diseases, such as heart disease and can- cer, are influenced by many genes and typically develop over several decades. -these chronic diseases have multiple genetic components that predispose the prevention or development of a disease, depending on a variety of environmental factors (such as smoking, diet, and physical activity).5 both types are of interest to researchers in nutritional genomics. -single-gene disorders some disorders are caused by mutations in single genes that are inherited at birth. -the consequences of a missing or malfunction- ing protein can seriously disrupt metabolism and may require sig- nificant dietary or medical intervention. -a classic example of a diet-related, single-gene disorder is phenylketonuria, or pku. -approximately one in every 15,000 infants in the united states is born with pku. -pku arises from mutations in the gene that codes for the enzyme that converts the essential amino acid phenylalanine to the amino acid tyrosine. -without this enzyme, phenylalanine and its metabolites accumulate and damage the nervous system, resulting in mental retardation, seizures, and be- havior abnormalities. -at the same time, the body cannot make ty- rosine or compounds made from it (such as the neurotransmitter epinephrine). -consequently, tyrosine becomes an essential amino acid: because the body cannot make it, the diet must supply it. -although the most debilitating effect is on brain development, other symptoms of pku become evident if the condition is left un- treated. -infants with pku may have poor appetites and grow slowly. -they may be irritable or have tremors or seizures. -their bodies and urine may have a musty odor. -their skin coloring may be unusually pale, and they may develop skin rashes. -the effect of nutrition intervention in pku is remarkable. -in fact, the only current treatment for pku is a diet that restricts phenylala- nine and supplies tyrosine to maintain blood levels of these amino acids within safe ranges. -because all foods containing protein pro- vide phenylalanine, the diet must depend on a formula to supply a phenylalanine-free source of energy, protein, vitamins, and miner- als. -if the restricted diet is conscientiously followed, the symptoms can be prevented. -because phenylalanine is an essential amino acid, the diet cannot exclude it completely. -children with pku need phenylalanine to grow, but they cannot handle excesses without detrimental effects. -therefore, their diets must provide enough phenylalanine to support normal growth and health but not enough to cause harm. -the diet must also provide tyrosine. -to en- sure that blood concentrations of phenylalanine and tyrosine are close to normal, children and adults who have pku must have blood tests periodically and adjust their diets as necessary. -multigene disorders in multigene disorders, each of the genes can influence the pro- gression of a disease, but no single gene causes the disease on its both of these mice have the gene that tends to produce fat, yellow pups, but their mothers had different diets. -the mother of the mouse on the right received a dietary supplement, which silenced the gene, resulting in brown pups with normal appetites. -obesity and some related diseases. -keep in mind that these changes occurred epigenetically. -in other words, the dna sequence within the genes of the mice remained the same. -whether silencing or activating a gene is beneficial or harmful depends on what the gene does. -silencing a gene that stimulates cancer growth, for example, would be beneficial, but silencing a gene that suppresses cancer growth would be harmful. -similarly, activating a gene that defends against obesity would be beneficial, but activating a gene that promotes obesity would be harmful. -much research is under way to determine which nutrients activate or silence which genes. -genetic variation and disease except for identical twins, no two persons are genetically identi- cal. -the variation in the genomes of any two persons, however, is only about 0.1 percent, a difference of only one nucleotide base in every 1000. yet it is this incredibly small difference that makes each of us unique and explains why, given the same environmen- tal influences, some of us develop certain diseases and others do not. -similarly, genetic variation explains why some of us respond to interventions such as diet and others do not. -for example, fol- lowing a diet low in saturated fats will significantly lower ldl cho- lesterol for most people, but the degree of change varies dramatically among individuals, with some people having only a small decrease or even a slight increase.3 in other words, dietary factors may be more helpful or more harmful depending on a person s particular genetic variations.4 (such findings help to ex- plain some of the conflicting results from research studies.) -the goal of nutritional genomics is to custom design specific recom- mendations that fit the needs of each individual. -such personal- ized recommendations are expected to provide more effective disease prevention and treatment solutions. -210 highlight 6 own. -for this reason, genomics researchers must study the ex- pression and interactions of multiple genes. -because multigene disorders are often sensitive to interactions with environmental influences, they are not as straightforward as single-gene disor- ders. -heart disease provides an example of a chronic disease with multiple gene and environmental influences. -consider that major risk factors for heart disease include elevated blood cholesterol levels, obesity, diabetes, and hypertension, yet the underlying ge- netic and environmental causes of any of these individual risk fac- tors is not completely understood. -genomic research can reveal details about each of these risk factors. -for example, tests could determine whether blood cholesterol levels are high due to in- creased cholesterol absorption or production or because of de- creased cholesterol degradation.6 this information could then guide physicians and dietitians to prescribe the most appropriate medical and dietary interventions from among many possible so- lutions.7 today s dietary recommendations advise a low-fat diet, which helps people with a small type of ldl but not those with the large type. -in fact, a low-fat diet is actually more harmful for people with the large type. -finding the best option for each per- son will be a challenge given the many possible interactions be- tween genes and environmental factors and the millions of possible gene variations in the human genome that make each in- dividual unique.8 the results of genomic research are helping to explain find- ings from previous nutrition research. -consider dietary fat and heart disease, for example. -as highlight 5 explained, epidemio- logical and clinical studies have found that a diet high in unsatu- rated fatty acids often helps to maintain a healthy blood lipid profile. -now genetic studies offer an underlying explanation of this relationship: diets rich in polyunsaturated fatty acids activate genes responsible for making enzymes that break down fats and silence genes responsible for making enzymes that make fats.9 both actions change fat metabolism in the direction of lowering blood lipids. -to learn more about how individuals respond to diet, re- searchers examine the genetic differences between people. -the most common genetic differences involve a change in a single nucleotide base located in a particular region of a dna strand thymine replacing cytosine, for example. -such varia- tions are called single nucleotide polymorphisms (snps), and they commonly occur throughout the genome. -many snps (commonly pronounced snips ) have no effect on cell activity. -in fact, snps are significant only if they affect the amino acid sequence of a protein in a way that alters its function and if that function is critical to the body s well-being. -research on a gene that plays a key role in lipid metabolism reveals differences in a person s response to diet depending on whether the gene has a common snp. -people with the snp have lower ldl when eat- ing a diet rich in polyunsaturated fatty acids and higher ldl with a low intake than those without the snp.10 these find- ings clearly show how diet (in this case, polyunsaturated fat) interacts with a gene (in this case, a fat metabolism gene with a snp) to influence the development of a disease (changing blood lipids implicated in heart disease). -the quest now is to identify the genetic characteristics that predict various re- sponses to dietary recommendations.11 clinical concerns because multigene, chronic diseases are common, an under- standing of the human genome will have widespread ramifica- tions for health care. -this new understanding of the human genome is expected to change health care by: providing knowledge of an individual s genetic predisposition to specific diseases. -allowing physicians to develop designer therapies prescribing the most effective schedule of screening, behavior changes (in- cluding diet), and medical interventions based on each individual s genetic profile. -enabling manufacturers to create new medications for each ge- netic variation so that physicians can prescribe the best medicine in the exact dose and frequency to enhance effectiveness and mini- mize the risks of side effects. -providing a better understanding of the nongenetic factors that in- fluence disease development. -enthusiasm surrounding genomic research needs to be put into perspective, however, in terms of the present status of clini- cal medicine as well as people s willingness to make difficult lifestyle choices. -critics have questioned whether genetic markers for disease would be more useful than simple clinical measure- ments, which reflect both genetic and environmental influences. -in other words, knowing that a person is genetically predisposed to have high blood cholesterol is not necessarily more useful than knowing the person s actual blood cholesterol level.12 further- more, if a disease has many genetic risk factors, each gene that contributes to susceptibility may have little influence on its own, so the benefits of identifying an individual genetic marker might be small. -the long-range possibility is that many genetic markers will eventually be identified, and the hope is that the combined information will be a useful and accurate predictor of disease. -having the knowledge to prevent disease and actually taking action do not always coincide. -despite the abundance of current dietary recommendations, people seem unwilling to make behav- ior changes known to improve their health. -for example, it has been estimated that heart disease and type 2 diabetes are 90 per- cent preventable when people adopt an appropriate diet, main- tain a healthy body weight, and exercise regularly.13 yet these two diseases remain among the leading causes of death. -given the difficulty that people have with current recommendations, it may be unrealistic to expect that many of them will enthusiastically adopt an even more detailed list of lifestyle modifications. -then again, compliance may be better when it is supported by infor- mation based on a person s own genetic profile. -the debate over nature versus nurture whether genes or the environment are more influential has quieted. -the focus has shifted. -scientists acknowledge the important roles of each and understand the real answers lie within the myriad interactions. -current research is sorting through how nutrients (and other di- etary factors) and genes confer health benefits or risks. -answers from genomic research may not become apparent for years to come, but the opportunities and rewards may prove well worth the efforts.14 nutritional genomics 211 nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 6, then to highlights nutrition on the net. -get information about human genomic discoveries and how they can be used to improve health from the ge- nomics and disease prevention site of the centers for disease control: www.cdc.gov/genomics references 1. g. t. keusch, what do omics mean for the science and policy of the nutritional sci- ences? -american journal of clinical nutrition 83 (2006): 520s 522s. -2. n. fogg-johnson and j. kaput, nutrige- nomics: an emerging scientific discipline, food technology 57 (2003): 60 67; r. wein- shilboum, inheritance and drug response, new england journal of medicine 348 (2003): 529 537; a. e. guttmacher and f. s. collins, genomic medicine a primer, new england journal of medicine 347 (2002): 1512 1520. -3. d. corella and j. m. ordovas, single nucleo- tide polymorphisms that influence lipid metabolism: interaction with dietary fac- tors, annual review of nutrition 25 (2005): 341 390. -4. e. trujillo, c. davis, and j. milner, nutrige- nomics, proteomics, metabolomics, and the practice of dietetics, journal of the american dietetic association 106 (2006): 403 413. -5. j. kaput and coauthors, the case for strategic international alliances to harness nutri- tional genomics for public and personal health, british journal of nutrition 94 (2005): 623 632; j. kaput and r. l. rodriguez, nutritional genomics: the next frontier in the postgenome era, physiological genomics 16 (2004): 166 177. -6. j. b. german, m. a. roberts, and s. m. watkins, personal metabolomics as a next generation nutritional assessment, journal of nutrition 133 (2003): 4260 4266. -7. r. m. debusk and coauthors, nutritional genomics in practice: where do we begin? -journal of the american dietetic association 105 (2005): 589 597. -8. j. m. ordovas, nutrigenetics, plasma lipids, and cardiovascular risk, journal of the ameri- can dietetic association 106 (2006): 1074 1081. -9. h. sampath and j. m. ntambi, polyunsatu- rated fatty acid regulation of genes of lipid metabolism, annual review of nutrition 25 (2005): 317 340. -10. e. s. tai and coauthors, polyunsaturated fatty acids interact with ppara l162v polymorphism to affect plasma triglyceride apolipoprotein c-iii concentrations in the framingham heart study, journal of nutrition 135 (2005): 397 403. -11. j. m. ordovas, the quest for cardiovascular health in the genomic era: nutrigenetics and plasma lipoproteins, proceedings of the nutrition society 63 (2004): 145 152. -12. w. c. willett, balancing life-style and ge- nomics research for disease prevention, science 296 (2002): 695 698. -13. s. yusut and coauthors, effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the interheart study): case-control study, lancet 364 (2004): 937 952; willett, 2002. -14. a. e. guttmacher and f. s. collins, realizing the promise of genomics in biomedical research, journal of the american medical association 294 (2005): 1399 1402; p. j. stover, nutritional genomics, physiological genomics 16 (2004): 161 165. burke/triolo productions/foodpix/jupiter images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/login figure 7.5: animated! -glycolysis: glucose-to-pyruvate figure 7.10: animated! -fatty acid-to-acetyl coa figure 7.18: animated! -the tca cycle figure 7.19: animated! -electron transport chain and atp synthesis nutrition portfolio journal you eat breakfast and hustle off to class. -after lunch, you study for tomorrow s exam. -dinner is followed by an evening of dancing. -do you ever think about how the food you eat powers the activities of your life? -what happens when you don t eat or when you eat too much? -learn how the cells of your body transform carbohydrates, fats, and proteins into energy and what happens when you give your cells too much or too little of any of these nutrients. -discover the metabolic pathways that lead to body fat and those that support physical activity. -it s really quite fascinating. -metabolism: transformations and interactions energy makes it possible for people to breathe, ride bicycles, compose mu- sic, and do everything else they do. -all the energy that sustains human life initially comes from the sun the ultimate source of energy. -as chapter 1 explained, energy is the capacity to do work. -although every aspect of our lives depends on energy, the concept of energy can be difficult to grasp be- cause it cannot be seen or touched, and it manifests in various forms, in- cluding heat, mechanical, electrical, and chemical energy. -in the body, heat energy maintains a constant body temperature, and electrical energy sends nerve impulses. -energy is stored in foods and in the body as chemi- cal energy. -during photosynthesis, plants make simple sugars from carbon diox- ide and capture the sun s light energy in the chemical bonds of those sug- ars. -then human beings eat either the plants or animals that have eaten the plants. -these foods provide energy, but how does the body obtain that energy from foods? -this chapter answers that question by following the nutrients that provide the body with fuel through a series of reactions that release energy from their chemical bonds. -as the bonds break, they release energy in a controlled version of the same process by which wood burns in a fire. -both wood and food have the potential to provide energy. -when wood burns in the presence of oxygen, it generates heat and light (energy), steam (water), and some carbon dioxide and ash (waste). -similarly, during metabolism, the body releases energy, water, and carbon dioxide. -by studying metabolism, you will understand how the body uses foods to meet its needs and why some foods meet those needs better than others. -readers who are interested in weight control will discover which foods con- tribute most to body fat and which to select when trying to gain or lose weight safely. -physically active readers will discover which foods best sup- port endurance activities and which to select when trying to build lean body mass. -c h a p t e r 7 chapter outline chemical reactions in the body breaking down nutrients for energy glucose glycerol and fatty acids amino acids breaking down nutrients for energy in summary the final steps of catabolism energy balance feasting excess energy the transition from feasting to fasting fasting inadequate energy highlight 7 alcohol and nutrition photosynthesis: the process by which green plants use the sun s energy to make carbohydrates from carbon dioxide and water. -photo = light synthesis = put together (making) fuel: compounds that cells can use for energy. -the major fuels include glucose, fatty acids, and amino acids; other fuels include ketone bodies, lactate, glycerol, and alcohol. -metabolism: the sum total of all the chemical reactions that go on in living cells. -energy metabolism includes all the reactions by which the body obtains and expends the energy from food. -metaballein = change 213 214 chapter 7 anabolism (an-ab-o-lism): reactions in which small molecules are put together to build larger ones. -anabolic reactions require energy. -ana = up chemical reactions in the body earlier chapters introduced some of the body s chemical reactions: the making and breaking of the bonds in carbohydrates, lipids, and proteins. -metabolism is the sum of these and all the other chemical reactions that go on in living cells; energy metab- olism includes all the ways the body obtains and uses energy from food. -the site of metabolic reactions cells the human body is made up of tril- lions of cells, and each cell busily conducts its metabolic work all the time. -(appen- dix a presents a brief summary of the structure and function of the cell.) -figure 7-1 depicts a typical cell and shows where the major reactions of energy metabolism take place. -the type and extent of metabolic activities vary depending on the type of cell, but of all the body s cells, the liver cells are the most versatile and metaboli- cally active. -table 7-1 offers insights into the liver s work. -the building reactions anabolism earlier chapters described how condensa- tion reactions combine the basic units of energy-yielding nutrients to build body compounds. -glucose molecules may be joined together to make glycogen chains. -glycerol and fatty acids may be assembled into triglycerides. -amino acids may be linked together to make proteins. -each of these reactions starts with small, simple compounds and uses them as building blocks to form larger, more complex struc- tures. -because such reactions involve doing work, they require energy. -the building up of body compounds is known as anabolism. -anabolic reactions are represented in this book, wherever possible, with up arrows in chemical diagrams (such as those shown in figure 7-2). -figure 7-1 a typical cell (simplified diagram) inside the cell membrane lies the cytoplasm, a lattice-type structure that supports and controls the movement of the cell s structures. -a protein-rich jelly-like fluid called cytosol fills the spaces within the lattice. -the cytosol contains the enzymes involved in glycolysis.a a separate inner membrane encloses the cell s nucleus. -inside the nucleus are the chromosomes, which contain the genetic material dna. -outer compartment outer membrane (site of fatty acid activation) cytosol (site of glycolysis) known as the powerhouses of the cells, the mitochondria are intricately folded membranes that house all the enzymes involved in the conversion of pyruvate to acetyl coa, fatty acid oxidation, the tca cycle, and the electron transport chain.b a membrane encloses each cell s contents and regulates the passage of molecules in and out of the cell. -a mitochondrion the ribosomes, some of which are located on a system of intracellular membranes, assemble amino acids into proteins.c aglycolysis is introduced on p. 219. bthe conversion of pyruvate to acetyl coa, fatty acid oxidation, the tca cycle, and the electron transport chain are described later in the chapter.. cfigure 6-7 on p. 188 describes protein synthesis. -inner membrane (site of electron transport chain) inner compartment (site of pyruvate-to-acetyl coa, fatty acid oxidation, and tca cycle) metabolism: transformations and interactions 215 table 7-1 metabolic work of the liver the liver is the most active processing center in the body. -when nutrients enter the body from the diges- tive tract, the liver receives them first; then it metabolizes, packages, stores, or ships them out for use by other organs. -when alcohol, drugs, or poisons enter the body, they are also sent directly to the liver; here they are detoxified and their by-products shipped out for excretion. -an enthusiastic anatomy and physiol- ogy professor once remarked that given the many vital activities of the liver, we should express our feel- ings for others by saying, i love you with all my liver, instead of with all my heart. -granted, this decla- ration lacks romance, but it makes a valid point. -here are just some of the many jobs performed by the liver. -to renew your appreciation for this remarkable organ, review figure 3-12 on p. 85. carbohydrates: proteins: converts fructose and galactose to glucose manufactures nonessential amino acids that are in short supply makes and stores glycogen breaks down glycogen and releases glucose breaks down glucose for energy when needed makes glucose from some amino acids and glycerol when needed converts excess glucose to fatty acids lipids: builds and breaks down triglycerides, phospholipids, and cholesterol as needed breaks down fatty acids for energy when needed removes from circulation amino acids that are present in excess of need and converts them to other amino acids or deaminates them and converts them to glucose or fatty acids removes ammonia from the blood and converts it to urea to be sent to the kidneys for excretion makes other nitrogen-containing compounds the body needs (such as bases used in dna and rna) makes plasma proteins such as clotting factors other: detoxifies alcohol, other drugs, and poisons; prepares waste products for packages extra lipids in lipoproteins for transport to other body organs excretion manufactures bile to send to the gallbladder for use in fat digestion helps dismantle old red blood cells and captures the iron for recycling makes ketone bodies when necessary stores most vitamins and many minerals figure 7-2 anabolic and catabolic reactions compared anabolic reactions glycogen triglycerides protein uses energy uses energy uses energy glucose + glucose glycerol + fatty acids amino acids + amino acids anabolic reactions include the making of glycogen, triglycerides, and protein; these reactions require differing amounts of energy. -catabolic reactions glycogen triglycerides protein glucose glycerol fatty acids amino acids yields energy yields energy yields energy yields energy catabolic reactions include the breakdown of glycogen, triglycerides, and protein; the further catabolism of glucose, glycerol, fatty acids, and amino acids releases differing amounts of energy. -much of the energy released is capturedin the bonds of adenosine triphosphate (atp). -note: you need not memorize a color code to understand the figures in this chapter, but you may find it helpful to know that blue is used for carbohydrates, yellow for fats, and red for proteins. -216 chapter 7 figure 7-3 atp (adenosine triphosphate) atp is one of the body s high-energy molecules. -notice that the bonds connecting the three phosphate groups have been drawn as wavy lines, indicating a high- energy bond. -when these bonds are broken, energy is released. -nh2 n n n n o ch2 o o p o- o o p o o- o p o- o- oh oh adenosine + 3 phosphate groups the breakdown reactions catabolism the breaking down of body com- pounds is known as catabolism; catabolic reactions release energy and are repre- sented, wherever possible, by down arrows in chemical diagrams (as in figure 7-2, p. 215). -earlier chapters described how hydrolysis reactions break down glycogen to glucose, triglycerides to fatty acids and glycerol, and proteins to amino acids. -when the body needs energy, it breaks down any or all of these four basic units into even smaller units, as described later. -the transfer of energy in reactions atp high-energy storage com- pounds in the body capture some of the energy released during the breakdown of glucose, glycerol, fatty acids, and amino acids from foods. -one such com- pound is atp (adenosine triphosphate). -atp, as its name indicates, con- tains three phosphate groups (see figure 7-3). -the bonds connecting the phosphate groups are often described as high-energy bonds, referring to the bonds readiness to release their energy. -the negative charges on the phosphate groups make atp vulnerable to hydrolysis. -whenever cells do any work that requires energy, hydrolytic reactions readily break these high-energy bonds of atp, splitting off one or two phosphate groups and releasing their energy. -quite often, the hydrolysis of atp occurs simultaneously with reactions that will use that energy a metabolic duet known as coupled reactions. -figure 7-4 illustrates how the body captures and releases energy in the bonds of atp. -in essence, the body uses atp to transfer the energy released during catabolic reac- tions to power its anabolic reactions. -the body converts the chemical energy of food to the chemical energy of atp with about 50 percent efficiency, radiating the rest as heat.1 energy is lost as heat again when the body uses the chemical energy of atp to do its work moving muscles, synthesizing compounds, or transporting nutrients, for example. -the helpers in metabolic reactions enzymes and coenzymes metabolic reactions almost always require enzymes to facilitate their action. -in many cases, the enzymes need assistants to help them. -enzyme helpers are called coenzymes. -coenzymes are complex organic molecules that associate closely with most en- zymes but are not proteins themselves. -the relationships between various coen- zymes and their respective enzymes may differ in detail, but one thing is true of all: without its coenzyme, an enzyme cannot function. -some of the b vitamins serve as coenzymes that participate in the energy metabolism of glucose, glycerol, fatty acids, and amino acids (chapter 10 provides more details). -atp = a-p~p~p. -(each ~ denotes a high-energy bond.) -reminder: enzymes are protein catalysts proteins that facilitate chemical reactions without being changed in the process. -the general term for substances that facili- tate enzyme action is cofactors; they include both organic coenzymes made from vitamins and inorganic substances such as minerals. -catabolism (ca-tab-o-lism): reactions in which large molecules are broken down to smaller ones. -catabolic reactions release energy. -kata = down atp or adenosine (ah-den-oh-seen) triphosphate (try-fos-fate): a common high-energy compound composed of a purine (adenine), a sugar (ribose), and three phosphate groups. -coupled reactions: pairs of chemical reactions in which some of the energy released from the breakdown of one compound is used to create a bond in the formation of another compound. -coenzymes: complex organic molecules that work with enzymes to facilitate the enzymes activity. -many coenzymes have b vitamins as part of their structures (figure 10-1 on p. 327 in chapter 10 illustrates coenzyme action). -co = with metabolism: transformations and interactions 217 figure 7-4 transfer of energy by atp a coupled reaction the breakdown of atp (adenosine triphosphate) to adp (adenosine diphosphate) releases energy that can be used to power another reaction (such as the synthesis of a needed compound). -the simultaneous occurrence of one reaction releasing energy and another reaction using the energy is called a coupled reaction. -a p p p atp atp captures and stores energy in the bonds between its phosphate groups. -adp + p a p p p+ energy from the breakdown of carbohydrate, fat, and protein is used to attach a phosphate group to adp, making atp. -energy from atp is released when a high-energy phosphate bond is broken. -this energy is used in a coupled reaction to do the body s work. -with the loss of a phosphate group, atp becomes adp. -in summary during digestion the energy-yielding nutrients carbohydrates, lipids, and proteins are broken down to glucose (and other monosaccharides), glycerol, fatty acids, and amino acids. -aided by enzymes and coenzymes, the cells use these products of digestion to build more complex compounds (anabolism) or break them down further to release energy (catabolism). -high-energy com- pounds such as atp may capture the energy released during catabolism. -breaking down nutrients for energy chapters 4, 5, and 6 laid the groundwork for the study of metabolism; a brief review may be helpful. -during digestion, the body breaks down the three energy-yielding nutrients carbohydrates, lipids, and proteins into four basic units that can be ab- sorbed into the blood: from carbohydrates glucose (and other monosaccharides) from fats (triglycerides) glycerol and fatty acids from proteins amino acids the body uses carbohydrates and fats for most of its energy needs. -amino acids are used primarily as building blocks for proteins, but they also enter energy pathways, contributing about 10 to 15 percent of the day s energy use. -look for these four ba- sic units glucose, glycerol, fatty acids, and amino acids to appear again and again in the metabolic reactions described in this chapter. -alcohol also enters many of the metabolic pathways; highlight 7 focuses on how alcohol disrupts metabolism and how the body handles it. -glucose, glycerol, fatty acids, and amino acids are the basic units derived from food, but a molecule of each of these compounds is made of still smaller units, the atoms carbons, nitrogens, oxygens, and hydrogens. -during catabolism, the body 218 chapter 7 all the energy used to keep the heart beating, the brain thinking, and the legs running comes from the carbohydrates, fats, and proteins in foods. -a healthy diet provides: 45 65% kcalories from carbohydrate 10 35% kcalories from protein 20 35% kcalories from fat pyruvate (pie-roo-vate): a 3-carbon compound that plays a key role in energy metabolism. -ch3 c o cooh acetyl coa (ass-eh-teel, or ah-seet-il, coh- ay): a 2-carbon compound (acetate, or acetic acid, shown in figure 5-1 on p. 140) to which a molecule of coa is attached. -coa (coh-ay): coenzyme a; the coenzyme derived from the b vitamin pantothenic acid and central to energy metabolism. -tca cycle or tricarboxylic (try-car-box-ill- ick) acid cycle: a series of metabolic reactions that break down molecules of acetyl coa to carbon dioxide and hydrogen atoms; also called the kreb s cycle after the biochemist who elucidated its reactions. -electron transport chain: the final pathway in energy metabolism that transports electrons from hydrogen to oxygen and captures the energy released in the bonds of atp. -separates these atoms from one another. -to follow this action, recall how many carbons are in the backbones of these compounds: glucose has 6 carbons: glycerol has 3 carbons: c c c c c c c c c s e g a m i y t t e g / k n a b e g a m i e h t / e l o c s i r h c a fatty acid usually has an even number of carbons, commonly 16 or 18 carbons:* c c c c c c c c c c c c c c c c an amino acid has 2, 3, or more carbons with a nitrogen attached:** n n n c c c c c c c c c c full chemical structures and reactions appear both in the earlier chapters and in ap- pendix c; this chapter diagrams the reactions using just the compounds carbon and nitrogen backbones. -as you will see, each of the compounds glucose, glycerol, fatty acids, and amino acids starts down a different path. -along the way, two new names ap- pear pyruvate (a 3-carbon structure) and acetyl coa (a 2-carbon structure with a coenzyme, coa, attached) and the rest of the story falls into place around them. -two major points to notice in the following discussion: pyruvate can be used to make glucose. -acetyl coa cannot be used to make glucose. -a key to understanding these metabolic pathways is learning which fuels can be converted to glucose and which cannot. -the parts of protein and fat that can be converted to pyruvate can provide glucose for the body, whereas the parts that are converted to acetyl coa cannot provide glucose but can readily provide fat. -the body must have glucose to fuel the activities of the central nervous system and red blood cells. -without glucose from food, the body will devour its own lean (protein-containing) tissue to provide the amino acids to make glucose. -therefore, to keep this from happening, the body needs foods that can provide glucose pri- marily carbohydrate. -giving the body only fat, which delivers mostly acetyl coa, puts it in the position of having to break down protein tissue to make glucose. -giv- ing the body only protein puts it in the position of having to convert protein to glucose. -clearly, the best diet provides ample carbohydrate, adequate protein, and some fat. -eventually, all of the energy-yielding nutrients can enter the common path- ways of the tca cycle and the electron transport chain. -(similarly, people from three different cities can all enter an interstate highway and travel to the same destination.) -the tca cycle and electron transport chain have central roles in energy metabolism and receive full attention later in the chapter. -first, the text describes how each of the energy-yielding nutrients is broken down to acetyl coa and other compounds in preparation for their entrance into these final energy pathways. -* the figures in this chapter show 16- or 18-carbon fatty acids. -fatty acids may have 4 to 20 or more carbons, with chain lengths of 16 and 18 carbons most prevalent. -** the figures in this chapter usually show amino acids as compounds of 2, 3, or 5 carbons arranged in a straight line, but in reality amino acids may contain other numbers of carbons and assume other structural shapes (see appendix c). -the term pyruvate means a salt of pyruvic acid. -(throughout this book, the ending ate is used inter- changeably with ic acid; for our purposes they mean the same thing.) -metabolism: transformations and interactions 219 glucose what happens to glucose, glycerol, fatty acids, and amino acids during energy me- tabolism can best be understood by starting with glucose. -this discussion features glucose because of its central role in carbohydrate metabolism and because liver cells can convert the other monosaccharides (fructose and galactose) to compounds that enter the same energy pathways. -glucose-to-pyruvate the first pathway glucose takes on its way to yield energy is called glycolysis (glucose splitting). -* figure 7-5 shows a simplified drawing of glycolysis. -(this pathway actually involves several steps and several enzymes, which * glycolysis takes place in the cytosol of the cell (see figure 7-1, p. 214). -figure 7-5 animated! -glycolysis: glucose-to-pyruvate this simplified overview of glycolysis illustrates the steps in the process of converting glucose to pyruvate. -appendix c provides more details. -glycolysis (gly-coll-ih-sis): the metabolic breakdown of glucose to pyruvate. -glycolysis does not require oxygen (anaerobic). -glyco = glucose lysis = breakdown to test your understanding of these concepts, log on to www.thomsonedu .com/thomsonnow a little atp is used to start glycolysis. -galactose and fructose enter glycolysis at different places, but all continue on the same pathway. -in a series of reactions, the 6-carbon glucose is converted to other 6-carbon compounds, which eventually split into two interchangeable 3-carbon compounds. -glucose c c c c c c uses energy (atp) c c c c c c c c c c c c uses energy (atp) c c c c c c c c c c c c coenzyme coenzyme coenzyme h+ e coenzyme h+ e c c c c c c to electron transport chain a little atp is produced, and coenzymes carry the hydrogens and their electrons to the electron transport chain. -yields energy (atp) c c c c c c c c c c c c c c c c c c yields energy (atp) 2 pyruvate c c c c c c these 3-carbon compounds are converted to pyruvate. -glycolysis of one molecule of glucose produces two molecules of pyruvate. -note: these arrows point down indicating the breakdown of glucose to pyruvate during energy metabolism. -(alternatively, the arrows could point up indicating the making of glucose from pyruvate, but that is not the focus of this discussion.) -220 chapter 7 glucose pyruvate glucose may go down to make pyruvate, or pyruvate may go up to make glucose, depending on the cell s needs. -anaerobic (an-air-roe-bic): not requiring oxygen. -an = not aerobic (air-roe-bic): requiring oxygen. -mitochondria (my-toh-kon-dree-uh): the cellular organelles responsible for producing atp; made of membranes (lipid and protein) with enzymes mounted on them. -mitos = thread (referring to their slender shape) chondros = cartilage (referring to their external appearance) figure 7-6 pyruvate-to-lactate in the muscle: c c c c c c glucose coenzyme coenzyme yields energy (atp) coenzyme h are shown in appendix c.) in a series of reactions, the 6-carbon glucose is converted to similar 6-carbon compounds before being split in half, forming two 3-carbon compounds. -these 3-carbon compounds continue along the pathway until they are converted to pyruvate. -thus the net yield of one glucose molecule is two pyruvate molecules. -the net yield of energy at this point is small; to start glycolysis, the cell uses a little energy and then produces only a little more than it had to invest ini- tially. -* in addition, as glucose breaks down to pyruvate, hydrogen atoms with their electrons are released and carried to the electron transport chain by coenzymes made from the b vitamin niacin. -a later section of the chapter explains how oxygen accepts the electrons and combines with the hydrogens to form water and how the process captures energy in the bonds of atp. -this discussion focuses primarily on the breakdown of glucose for energy, but if needed, cells in the liver (and to some extent, the kidneys) can make glucose again from pyruvate in a process similar to the reversal of glycolysis. -making glucose requires energy, however, and a few different enzymes. -still, glucose can be made from pyru- vate, so the arrows between glucose and pyruvate could point up as well as down. -pyruvate s options pyruvate may enter either an anaerobic or an aerobic en- ergy pathway. -when the body needs energy quickly as occurs when you run a quarter mile as fast as you can pyruvate is converted to lactate in an anaerobic pathway. -when energy expenditure proceeds at a slower pace as occurs when you ride a bike for an hour pyruvate breaks down to acetyl coa in an aerobic pathway. -the following paragraphs explain these pathways. -pyruvate-to-lactate as mentioned earlier, coenzymes carry the hydrogens from glu- cose breakdown to the electron transport chain. -if the electron transport chain is un- able to accept these hydrogens, as may occur when cells lack sufficient mitochondria (review figure 7-1, p. 214) or in the absence of sufficient oxygen, pyruvate can accept the hydrogens. -as figure 7-6 shows, by accepting the hydrogens, pyruvate becomes * the cell uses 2 atp to begin the breakdown of glucose to pyruvate, but it then gains 4 atp for a net gain of 2 atp. -in the liver: glucose returns to the muscles c c c c c c glucose uses energy (atp) coenzyme h coenzyme coenzyme c c o c o c c c 2 pyruvate oh c oh c c c c c 2 lactate lactate travels to the liver c oh c oh c c c c 2 lactate working muscles break down most of their glucose molecules anaerobically to pyruvate. -if the cells lack sufficient mitochondria or in the absence of sufficient oxygen, pyruvate can accept the hydrogens from glucose breakdown and become lactate. -this conversion frees the coenzymes so that glycolysis can continue. -liver enzymes can convert lactate to glucose, but this reaction requires energy. -the process of converting lactate from the muscles to glucose in the liver that can be returned to the muscles is known as the cori cycle. -metabolism: transformations and interactions 221 s e g a m i y t t e g / i x a t / s n i m m u c m i j lactate, and the coenzymes are freed to return to glycolysis to pick up more hydrogens. -in this way, glucose can continue providing energy anaerobically for a while (see the left side of figure 7-6). -the production of lactate occurs to a limited extent even at rest. -during high- intensity exercise, however, the muscles rely heavily on anaerobic glycolysis to pro- duce atp quickly and the concentration of lactate increases dramatically. -the rapid rate of glycolysis produces abundant pyruvate and releases hydrogen- carrying coenzymes more rapidly than the mitochondria can handle them. -to en- able exercise to continue at this intensity, pyruvate is converted to lactate and coen- zymes are released, which allows glycolysis to continue (as mentioned earlier). -the accumulation of lactate in the muscles coincides with but is not the cause of the subsequent drop in blood ph, burning pain, and fatigue that are commonly associ- ated with intense exercise.2 in fact, making lactate from pyruvate consumes two hy- drogen ions, which actually diminishes acidity and improves the performance of tired muscles.3 a person performing the same exercise following endurance train- ing actually experiences less discomfort in part because the number of mitochon- dria in the muscle cells have increased. -this adaptation improves the mitochondria s ability to keep pace with the muscles demand for energy. -one possible fate of lactate is to be transported from the muscles to the liver. -there the liver can convert the lactate produced in muscles to glucose, which can then be returned to the muscles. -this recycling process is called the cori cycle (see figure 7-6). -(muscle cells cannot recycle lactate to glucose because they lack a nec- essary enzyme.) -whenever carbohydrates, fats, or proteins are broken down to provide energy, oxygen is always ultimately involved in the process. -the role of oxygen in metabo- lism is worth noticing, for it helps our understanding of physiology and metabolic re- actions. -chapter 14 describes the body s use of the energy nutrients to fuel physical activity, but the facts just presented offer a sneak preview. -the breakdown of glucose- to-pyruvate-to-lactate proceeds without oxygen it is anaerobic. -this anaerobic pathway yields energy quickly, but it cannot be sustained for long a couple of min- utes at most. -conversely, the aerobic pathways produce energy more slowly, but be- cause they can be sustained for a long time, their total energy yield is greater. -pyruvate-to-acetyl coa if the cell needs energy and oxygen is available, pyruvate molecules enter the mitochondria of the cell (review figure 7-1, p. 214). -there a carbon group (cooh) from the 3-carbon pyruvate is removed to produce a 2-carbon com- pound that bonds with a molecule of coa, becoming acetyl coa. -the carbon group from pyruvate becomes carbon dioxide, which is released into the blood, circulated to the lungs, and breathed out. -figure 7-7 diagrams the pyruvate-to-acetyl coa reaction. -the step from pyruvate to acetyl coa is metabolically irreversible: a cell cannot retrieve the shed carbons from carbon dioxide to remake pyruvate and then glucose. -it is a one-way step and is therefore shown with only a down arrow in figure 7-8. figure 7-8 the paths of pyruvate and acetyl coa pyruvate may follow several reversible paths, but the path from pyruvate to acetyl coa is irreversible. -the anaerobic breakdown of glucose-to-pyru- vate-to-lactate is the major source of energy for short, intense exercise. -figure 7-7 pyruvate-to-acetyl coa c c c c c c 2 pyruvate coenzyme coenzyme h+ e to electron transport chain 2 coa coenzyme coenzyme h+ e 2 carbon dioxide cc c c coa coa c c 2 acetyl coa to tca cycle each pyruvate loses a carbon as carbon dioxide and picks up a molecule of coa, becoming acetyl coa. -the arrow goes only one way (down) because the step is not reversible. -result: 1 glucose yields 2 pyruvate, which yield 2 carbon dioxide and 2 acetyl coa. -glucose pyruvate lactate: a 3-carbon compound produced from pyruvate during anaerobic metabolism. -glycerol lactate ch3 c oh cooh amino acids (glucogenic) amino acids (ketogenic) acetyl coa fatty acids note: amino acids that can be used to make glucose are called glucogenic; amino acids that are converted to acetyl coa are called ketogenic. -cori cycle: the path from muscle glycogen to glucose to pyruvate to lactate (which travels to the liver) to glucose (which can travel back to the muscle) to glycogen; named after the scientist who elucidated this pathway. -222 chapter 7 figure 7-9 glucose enters the energy pathway this figure combines figure 7-5 and figure 7-7 to show the breakdown of glucose-to-pyruvate-to-acetyl coa. -details of the tca cycle and the elec- tron transport chain are given later and in appendix c. glucose c c c c c c uses energy (atp) c c c c c c c c c c c c uses energy (atp) c c c c c c c c c c c c coenzyme coenzyme coenzyme h+ e coenzyme h+ e c c c c c c to electron transport chain yields energy (atp) c c c c c c c c c c c c c c c c c c yields energy (atp) 2 pyruvate c c c c c c coenzyme coenzyme 2 coa coenzyme coenzyme h+ e 2 carbon dioxide cc c c coa h+ e to electron transport chain c c coa 2 acetyl coa to tca cycle acetyl coa s options acetyl coa has two main functions it may be used to synthesize fats or to generate atp. -when atp is abundant, acetyl coa makes fat, the most efficient way to store energy for later use when energy may be needed. -thus any molecule that can make acetyl coa including glucose, glycerol, fatty acids, and amino acids can make fat. -in reviewing figure 7-8, notice that acetyl coa can be used as a building block for fatty acids, but it cannot be used to make glucose or amino acids. -when atp is low and the cell needs energy, acetyl coa may proceed through the tca cycle, releasing hydrogens, with their electrons, to the electron transport chain. -the story of acetyl coa continues on p. 227 after a discussion of how fat and protein arrive at the same crossroads. -for now, know that when acetyl coa from the breakdown of glucose enters the aerobic pathways of the tca cycle and elec- tron transport chain, much more atp is produced than during glycolysis. -the role of glycolysis is to provide energy for short bursts of activity and to prepare glucose for later energy pathways. -in summary the breakdown of glucose to energy begins with glycolysis, a pathway that produces pyruvate. -keep in mind that glucose can be synthesized only from pyruvate or compounds earlier in the pathway. -pyruvate may be converted to lactate anaerobically or to acetyl coa aerobically. -once the commitment to acetyl coa is made, glucose is not retrievable; acetyl coa cannot go back to glucose. -figure 7-9 summarizes the breakdown of glucose. -glycerol and fatty acids once glucose breakdown is understood, fat and protein breakdown are easily learned, for all three eventually enter the same metabolic pathways. -recall that triglycerides can break down to glycerol and fatty acids. -glycerol-to-pyruvate glycerol is a 3-carbon compound like pyruvate but with a different arrangement of h and oh on the c. as such, glycerol can easily be con- verted to another 3-carbon compound that can go either up the pathway to form glucose or down to form pyruvate and then acetyl coa (review figure 7-8, p. 221). -fatty acids-to-acetyl coa fatty acids are taken apart 2 carbons at a time in a series of reactions known as fatty acid oxidation. -* figure 7-10 illustrates fatty acid oxidation and shows that in the process, each 2-carbon fragment splits off and combines with a molecule of coa to make acetyl coa. -as each 2-carbon frag- ment breaks off from a fatty acid during oxidation, hydrogens and their electrons are released and carried to the electron transport chain by coenzymes made from the b vitamins riboflavin and niacin. -figure 7-11 (p. 224) summarizes the break- down of fats. -fatty acids cannot be used to synthesize glucose when carbohydrate is unavailable, the liver cells can make glucose from pyruvate and other 3-carbon compounds, such as glycerol, but they cannot make glucose from the 2-carbon frag- ments of fatty acids. -in chemical diagrams, the arrow between pyruvate and acetyl coa always points only one way down and fatty acid fragments enter the meta- bolic path below this arrow (review figure 7-8, p. 221). -the down arrow indicates that fatty acids cannot be used to make glucose. -fatty acid oxidation: the metabolic breakdown of fatty acids to acetyl coa; also called beta oxidation. -* oxidation of fatty acids occurs in the mitochondria of the cells (see figure 7-1, p. 214). -metabolism: transformations and interactions 223 figure 7-10 animated! -fatty acid-to-acetyl coa fatty acids are broken apart into 2-carbon fragments that combine with coa to make acetyl coa. -to test your understanding of these concepts, log on to www .thomsonedu.com/thomsonnow 16-c fatty acid the fatty acid is first activated by coenzyme a. c c c c c c c c c c c c c c coa uses energy (atp) c c c c c c c c c c c c c c h h c h h h c h o c oh o c coa as each carbon-carbon bond is cleaved, hydrogens and their electrons are released, and coenzymes pick them up. -coenzyme coenzyme coenzyme coa coenzyme h+ e h+ e to electron transport chain another coa joins the chain, and the bond at the second carbon (the beta- carbon) weakens. -acetyl coa splits off, leaving a fatty acid that is two carbons shorter. -h h c h c c c c c c c c c c c c o c coa + c c coa to tca cycle the shorter fatty acid enters the pathway and the cycle repeats, releasing more hydrogens with their electrons and more acetyl coa. -the molecules of acetyl coa enter the tca cycle, and the coenzymes carry the hydrogens and their electrons to the electron transport chain. -net result from a 16-c fatty acid: 14-c fatty acid coa cycle repeats, leaving: 12-c fatty acid coa cycle repeats, leaving: 10-c fatty acid coa cycle repeats, leaving: 8-c fatty acid coa cycle repeats, leaving: 6-c fatty acid coa cycle repeats, leaving: 4-c fatty acid coa cycle repeats, leaving: 2-c fatty acid coa* + + + + + + + 1 acetyl coa 2 acetyl coa 3 acetyl coa 4 acetyl coa 5 acetyl coa 6 acetyl coa 7 acetyl coa *notice that 2-c fatty acid coa = acetyl coa, so that the final yield from a 16-c fatty acid is 8 acetyl coa. -the significance of fatty acids not being able to make glucose is that red blood cells and the brain and nervous system depend primarily on glucose as fuel. -remember that almost all dietary fats are triglycerides and that triglycerides contain only one small molecule of glycerol with three fatty acids. -the glycerol can yield glucose, but that represents only 3 of the 50 or so carbon atoms in a triglyceride about 5 percent of its weight (see figure 7-12). -the other 95 percent cannot be converted to glucose. -in summary the body can convert the small glycerol portion of a triglyceride to either pyru- vate (and then glucose) or acetyl coa. -the fatty acids of a triglyceride, on the other hand, cannot make glucose, but they can provide abundant acetyl coa. -acetyl coa may then enter the tca cycle to release energy or combine with other molecules of acetyl coa to make body fat. -reminder: the making of glucose from non- carbohydrate sources is called gluconeogene- sis. -the glycerol portion of a triglyceride and most amino acids can be used to make glu- cose (review figure 7-8, p. 221). -the liver is the major site of gluconeogenesis, but the kidneys become increasingly involved under certain circumstances, such as starvation. -224 chapter 7 figure 7-11 animated! -fats enter the energy pathway to test your understanding of these concepts, log on to www .thomsonedu.com/thomsonnow glucose c c c c c c fat (triglycerides) c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c glycerol c c c pyruvate c c c c c c c c c c c c c c c c fatty acids coa coa carbon dioxide c coa c c acetyl coa to tca cycle c c c c coa a o c coenzyme c c c o a h+ e c c c c coenzyme c c a a o o c c c o a c c c c coa h+ e a o c to electron transport chain glycerol enters the glycolysis pathway about midway between glucose and pyruvate and can be converted to either. -fatty acids are broken down into 2-carbon fragments that combine with coa to form acetyl coa (shown in figure 7-10). -result: a 16-carbon fatty acid yields 8 acetyl coa. -figure 7-12 the carbons of a typical triglyceride glycerol fatty acids c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c 3 c 18 c 18 c 18 c 54 c a typical triglyceride contains only one small molecule of glycerol (3 c) but has three fatty acids (each commonly 16 c or 18 c, or about 48 c to 54 c in total). -only the glycerol portion of a triglyceride can yield glucose. -amino acids the preceding two sections have described how the breakdown of carbohydrate and fat produces acetyl coa, which can enter the pathways that provide energy for the body s use. -one energy-yielding nutrient remains: protein or, rather, the amino acids of protein. -figure 7-13 amino acids enter the energy pathway amino acids n c c c most amino acids can be used to synthesize glucose; they are glucogenic. -n h2 n h2 metabolism: transformations and interactions 225 c c c pyruvate coa coenzyme coenzyme h+ e carbon dioxide c to electron transport chain some amino acids are converted directly to acetyl coa; they are ketogenic. -c c c c some amino acids can enter the tca cycle directly; they are glucogenic. -n c c c c c c n h2 n n h2 n h2 c c coa acetyl coa to tca cycle note: the arrows from pyruvate and the tca cycle to amino acids are possible only for nonessential amino acids; remember, the body cannot make essential amino acids. -amino acids-to-acetyl coa before entering the metabolic pathways, amino acids are deaminated (that is, they lose their nitrogen-containing amino group) and then they are catabolized in a variety of ways. -as figure 7-13 illustrates, some amino acids can be converted to pyruvate, others are converted to acetyl coa, and still others enter the tca cycle directly as compounds other than acetyl coa. -amino acids-to-glucose as you might expect, amino acids that are used to make pyruvate can provide glucose, whereas those used to make acetyl coa can provide additional energy or make body fat but cannot make glucose. -amino acids entering the tca cycle directly can continue in the cycle and generate energy; alternatively, they can generate glucose.4 thus protein, unlike fat, is a fairly good source of glucose when carbohydrate is not available. -deamination when amino acids are metabolized for energy or used to make glu- cose or fat, they must be deaminated first. -two products result from deamination. -one is the carbon structure without its amino group often a keto acid (see figure 7-14, p. 226). -the other product is ammonia (nh3), a toxic compound chemically identical to the strong-smelling ammonia in bottled cleaning solutions. -ammonia is a base, and if the body produces larger quantities than it can handle, the blood s critical acid-base balance becomes upset. -transamination as the discussion of protein in chapter 6 pointed out, only some amino acids are essential; others can be made in the body, given a source of nitrogen. -by transferring an amino group from one amino acid to its correspon- ding keto acid, cells can make a new amino acid and a new keto acid, as shown in figure 7-15 (p. 226). -through many such transamination reactions, involv- ing many different keto acids, the liver cells can synthesize the nonessential amino acids. -ammonia-to-urea in the liver the liver continuously produces small amounts of ammonia in deamination reactions. -some of this ammonia provides the nitrogen amino acids that can make glucose via either pyruvate or tca cycle intermediates are glucogenic; amino acids that are degraded to acetyl coa are ketogenic. -keto (key-toe) acid: an organic acid that contains a carbonyl group (c=o). -ammonia: a compound with the chemical formula nh3; produced during the deamination of amino acids. -transamination (trans-am-ih-nay-shun): the transfer of an amino group from one amino acid to a keto acid, producing a new nonessential amino acid and a new keto acid. -226 chapter 7 figure 7-14 deamination and syn- thesis of a nonessential amino acid side group h c nh2 cooh side group c o cooh nh3 amino acid keto acid the deamination of an amino acid produces ammonia (nh3) and a keto acid. -side group c o cooh side group h c nh2 cooh nh3 keto acid amino acid given a source of nh3, the body can make nonessential amino acids from keto acids. -figure 7-16 urea synthesis when amino acids are deaminated, ammonia is produced. -the liver detoxi- fies ammonia before releasing it into the bloodstream by combining it with another waste product, carbon dioxide, to produce urea. -see appendix c for details. -h h n h ammonia + o c o carbon dioxide + h n h h ammonia h o h water h nh o c h n h urea urea (you-ree-uh): the principal nitrogen- excretion product of protein metabolism. -two ammonia fragments are combined with carbon dioxide to form urea. -figure 7-15 transamination and synthesis of a nonessential amino acid side group c o cooh side group h c nh2 cooh side group h c nh2 cooh side group c o cooh keto acid a + amino acid b amino acid a + keto acid b the body can transfer amino groups (nh2) from an amino acid to a keto acid, forming a new nonessential amino acid and a new keto acid. -transamination reactions require the vitamin b6 coenzyme. -needed for the synthesis of nonessential amino acids (review figure 7-14). -the liver quickly combines any remaining ammonia with carbon dioxide to make urea, a much less toxic compound. -figure 7-16 provides a greatly oversimplified diagram of urea synthesis; details are shown in appendix c. urea excretion via the kidneys liver cells release urea into the blood, where it circulates until it passes through the kidneys (see figure 7-17). -the kidneys then re- move urea from the blood for excretion in the urine. -normally, the liver efficiently captures all the ammonia, makes urea from it, and releases the urea into the blood; then the kidneys clear all the urea from the blood. -this division of labor allows easy diagnosis of diseases of both organs. -in liver disease, blood ammonia will be high; in kidney disease, blood urea will be high. -urea is the body s principal vehicle for excreting unused nitrogen, and the amount of urea produced increases with protein intake. -to keep urea in solution, the body needs water. -for this reason, a person who regularly consumes a high- protein diet (say, 100 grams a day or more) must drink plenty of water to dilute and excrete urea from the body. -without extra water, a person on a high-protein diet risks dehydration because the body uses its water to rid itself of urea. -this explains some of the water loss that accompanies high-protein diets. -such losses may make high-protein diets appear to be effective, but water loss, of course, is of no value to the person who wants to lose body fat (as highlight 9 explains). -in summary the body can use some amino acids to produce glucose, whereas others can be used either to generate energy or to make fat. -before an amino acid enters any of these metabolic pathways, its nitrogen-containing amino group must be re- moved through deamination. -deamination, which produces ammonia (nh3), may be used to make nonessential amino acids and other nitrogen-containing compounds; the rest is cleared from the body via urea synthesis in the liver and excretion via the kidneys. -breaking down nutrients for energy in summary to review the ways the body can use the energy-yielding nutrients, see the summary table (p. 227). -to obtain energy, the body uses glucose and fatty acids as its primary fuels and amino acids to a lesser extent. -to make glucose, the body can use all car- bohydrates and most amino acids, but it can convert only 5 percent of fat (the glyc- erol portion) to glucose. -to make proteins, the body needs amino acids. -it can use glucose to make some nonessential amino acids when nitrogen is available; it can- not use fats to make body proteins. -finally, when energy is consumed beyond the body s needs, all three energy-yielding nutrients can contribute to body fat stores. -metabolism: transformations and interactions 227 in summary nutrient carbohydrates (glucose) yields energy? -yields glucose? -yes yes yields amino acids and body proteins? -yes when nitrogen is available, can yield nonessential amino acids yields fat stores?a yes figure 7-17 urea excretion the liver and kidneys both play a role in disposing of excess nitrogen. -can you see why the person with liver disease has high blood ammonia, whereas the per- son with kidney disease has high blood urea? -(figure 12-2 provides details of how the kidneys work.) -amino acids bloodstream liver bloodstream ammonia (nh3) + co2 urea urea kidney urea to bladder and out of body lipids (fatty acids) lipids (glycerol) yes yes proteins (amino acids) yes no no yes when carbohydrate is unavailable yes when carbohydrate is unavailable yes when nitrogen is available, can yield nonessential amino acids yes yes yes yes awhen energy intake exceeds needs, any of the energy-yielding nutrients can contribute to body fat stores. -the final steps of catabolism thus far the discussion has followed each of the energy-yielding nutrients down three different pathways. -all lead to the point where acetyl coa enters the tca cy- cle. -the tca cycle reactions take place in the inner compartment of the mitochon- dria. -examine the structure of the mitochondria shown in figure 7-1 (p. 214). -the significance of its structure will become evident as details unfold. -the tca cycle acetyl coa enters the tca cycle, a busy metabolic traffic center. -the tca cycle is called a cycle, but that doesn t mean it regenerates acetyl coa. -acetyl coa goes one way only down to two carbon dioxide molecules and a coen- zyme (coa). -the tca cycle is a circular path, though, in the sense that a 4-carbon compound known as oxaloacetate is needed in the first step and synthesized in the last step. -oxaloacetate s role in replenishing the tca cycle is critical. -when oxaloacetate is insufficient, the tca cycle slows down, and the cells face an energy crisis. -ox- aloacetate is made primarily from pyruvate, although it can also be made from certain amino acids. -importantly, oxaloacetate cannot be made from fat. -that ox- aloacetate must be available for acetyl coa to enter the tca cycle underscores the importance of carbohydrates in the diet. -a diet that provides ample carbohydrate ensures an adequate supply of oxaloacetate (because glucose produces pyruvate during glycolysis). -(highlight 9 presents more information on the consequences of low-carbohydrate diets.) -as figure 7-18 shows, oxaloacetate is the first 4-carbon compound to enter the tca cycle. -oxaloacetate picks up acetyl coa (a 2-carbon compound), drops off one carbon (as carbon dioxide), then another carbon (as carbon dioxide), and returns to pick up another acetyl coa. -as for the acetyl coa, its carbons go only one way to carbon dioxide (see appendix c for additional details). -* * actually, the carbons that enter the cycle in acetyl coa may not be the exact ones that are given off as carbon dioxide. -in one of the steps of the cycle, a 6-carbon compound of the cycle becomes symmet- rical, both ends being identical. -thereafter it loses carbons to carbon dioxide at one end or the other. -thus only half of the carbons from acetyl coa are given off as carbon dioxide in any one turn of the cycle; the other half become part of the compound that returns to pick up another acetyl coa. -it is true to say, though, that for each acetyl coa that enters the tca cycle, 2 carbons are given off as carbon dioxide. -it is also true that with each turn of the cycle, the energy equivalent of one acetyl coa is released. -oxaloacetate (oks-ah-low-as-eh-tate): a carbohydrate intermediate of the tca cycle. -228 chapter 7 figure 7-18 animated! -the tca cycle oxaloacetate, a compound made primarily from pyruvate, starts the tca cycle. -the 4-carbon oxaloacetate joins with the 2-carbon acetyl coa to make a 6-carbon compound. -this compound is changed a little to make a new 6-carbon compound, which releases carbons as car- bon dioxide, becoming a 5- and then a 4-carbon compound. -each reaction changes the structure slightly until finally the original 4-carbon oxaloacetate forms again and picks up another acetyl coa from the breakdown of glucose, glycerol, fatty acids, and amino acids and starts the cycle over again. -the breakdown of acetyl coa releases hydrogens with their electrons, which are carried by coenzymes made from the b vitamins niacin and riboflavin to the electron transport chain. -(for more details, see appendix c.) to test your understanding of these concepts, log on to www .thomsonedu.com/thomsonnow pyruvate c c c acetyl coa c c coa c (from carbon dioxide) c (as carbon dioxide) c c c c oxaloacetate coenzyme coenzyme h+ e c c c c c c c c coenzyme coenzyme h+ e c c c c to electron transport chain c c c c coa c c c c c c c c c c c c coenzyme coenzyme h+ e c (as carbon dioxide) c c c c c coenzyme coenzyme h+ e yields energy (captured in high-energy compound similar to atp) c (as carbon dioxide) to electron transport chain note: knowing that glucose produces pyruvate during glycolysis and that oxaloacetate must be available to start the tca cycle, you can understand why the complete oxidation of fat requires carbohydrate. -as acetyl coa molecules break down to carbon dioxide, hydrogen atoms with their electrons are removed from the compounds in the cycle. -each turn of the tca cycle releases a total of eight electrons. -coenzymes made from the b vitamins niacin and riboflavin receive the hydrogens and their electrons from the tca cycle and transfer them to the electron transport chain much like a taxi cab that picks up passengers in one location and drops them off in another. -metabolism: transformations and interactions 229 the electron transport chain in the final pathway, the electron transport chain, energy is captured in the high-energy bonds of atp. -the electron transport chain consists of a series of proteins that serve as electron carriers. -these carriers are mounted in sequence on the inner membrane of the mitochondria (review fig- ure 7-1 on p. 214). -as the coenzymes deliver their electrons from the tca cycle, gly- colysis, and fatty acid oxidation to the electron transport chain, each carrier receives the electrons and passes them on to the next carrier. -these electron carriers continue passing the electrons down until they reach oxygen at the end of the chain. -oxygen (o) accepts the electrons and combines with hydrogen atoms (h) to form water (h2o). -that oxygen must be available for energy metabolism explains why it is essential to life. -as electrons are passed from carrier to carrier, enough energy is released to pump hydrogen ions across the membrane to the outer compartment of the mito- chondria. -the rush of hydrogen ions back into the inner compartment powers the synthesis of atp. -in this way, energy is captured in the bonds of atp. -the atp leaves the mitochondria and enters the cytoplasm, where it can be used for energy. -figure 7-19 provides a simple diagram of the electron transport chain (see appendix c for details). -the kcalories-per-gram secret revealed of the three energy-yielding nutri- ents, fat provides the most energy per gram. -the reason may be apparent in fig- ure 7-20 (p. 230), which compares a fatty acid with a glucose molecule. -notice that nearly all the bonds in the fatty acid are between carbons and hydrogens. -oxygen can be added to all of them (forming carbon dioxide with the carbons and water with the hydrogens). -as this happens, hydrogens are released to coenzymes heading figure 7-19 animated! -electron transport chain and atp synthesis to test your understanding of these concepts, log on to www .thomsonedu.com/thomsonnow the results of the electron transport chain: o2 consumed h2o and co2 produced energy captured in atp fat = 9 kcal/g carbohydrate = 4 kcal/g protein = 4 kcal/g electron transport chain atp synthesis passing electrons from carrier to carrier along the chain releases enough energy to pump hydrogen ions across the membrane. -h+ h+ h+ h+ h+ h+ h+ h+ h+ h+ h+ outer compartment inner membrane electron carrier electron carrier electron carrier electron carrier inner compartment h+ e h+ coenzymes h+ h+ coenzymes deliver hydrogens and high-energy electrons to the electron transport chain from the tca cycle. -h+ hydrogens + oxygen oxygen accepts the electrons and combines with hydrogens to form water. -h+ h+ hydrogen ions flow downhill from an area of high concentration to an area of low concentration through a special protein complex that powers the synthesis of atp. -h+ h+ h+ h+ h+ h+ h+ h+ h+ h+ h+ h+ water a p p adp + + p p a p p p atp 230 chapter 7 figure 7-20 chemical structures of a fatty acid and glucose compared to ease comparison, the structure shown here for glucose is not the ring structure shown in chapter 4, but an alternative way of drawing its chemical structure. -h h c h h c h h c h h c h h c h h c h h c h h c h h c h h c h h c h h c h h c h h c h h c h o c oh hoch2 fatty acid h c h c oh h c c o c h oh h oh glucose oh for the electron transport chain. -in glucose, on the other hand, an oxygen is already bonded to each carbon. -thus there is less potential for oxidation, and fewer hydro- gens are released when the remaining bonds are broken. -because fat contains many carbon-hydrogen bonds that can be readily oxidized, it sends numerous coenzymes with their hydrogens and electrons to the electron transport chain where that energy can be captured in the bonds of atp. -this ex- plains why fat yields more kcalories per gram than carbohydrate or protein. -(re- member that each atp holds energy and that kcalories measure energy; thus the more atp generated, the more kcalories have been collected.) -for example, one glu- cose molecule will yield 30 to 32 atp when completely oxidized.5 in comparison, one 16-carbon fatty acid molecule will yield 129 atp when completely oxidized. -fat is a more efficient fuel source. -gram for gram, fat can provide much more energy than either of the other two energy-yielding nutrients, making it the body s preferred form of energy storage. -(similarly, you might prefer to fill your car with a fuel that provides 130 miles per gallon versus one that provides 30 miles per gallon.) -in summary after a balanced meal, the body handles the nutrients as follows. -the diges- tion of carbohydrate yields glucose (and other monosaccharides); some is stored as glycogen, and some is broken down to pyruvate and acetyl coa to provide energy. -the acetyl coa can then enter the tca cycle and electron transport chain to provide more energy. -the digestion of fat yields glycerol and fatty acids; some are reassembled and stored as fat, and others are broken down to acetyl coa, which can enter the tca cycle and electron transport chain to provide energy. -the digestion of protein yields amino acids, most of which are used to build body protein or other nitrogen-containing com- pounds, but some amino acids may be broken down through the same path- ways as glucose to provide energy. -other amino acids enter directly into the tca cycle, and these, too, can be broken down to yield energy. -in summary, although carbohydrate, fat, and protein enter the tca cycle by differ- ent routes, the final pathways are common to all energy-yielding nutrients. -these pathways are all shown in figure 7-21. instead of dismissing this figure as too busy, take a few moments to appreciate the busyness of it all. -consider that this fig- ure is merely an overview of energy metabolism, and then imagine how busy a cell really is during the metabolism of hundreds of compounds, each of which may be involved in several reactions, each requiring an enzyme. -energy balance every day, a healthy diet delivers over a thousand kcalories from foods, and the ac- tive body uses most of them to do its work. -as a result, body weight changes little, if at all. -maintaining body weight reflects that the body s energy budget is balanced. -metabolism: transformations and interactions 231 figure 7-21 the central pathways of energy metabolism in reviewing these pathways, notice that: all of the energy-yielding nutrients protein, carbohydrates, and fat can be broken down to acetyl coa, which can enter the tca cycle. -many of these reactions release hydrogen atoms with their electrons, which are carried by coenzymes to the electron transport chain, where atp is synthesized. -in the end, oxygen is consumed, water and carbon dioxide are produced, and energy is captured in atp. -fat (triglycerides) c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c carbohydrates c c c c glucose c c amino acids coenzyme h+ e c c c pyruvate c c c c c c c c c c c glycerol c c c c c c c c fatty acids c c coa coa coenzyme h+ e n c c c n h2 n h2 c c c c n c c n h2 coenzyme h+ e carbon dioxide c coa c c acetyl coa coa coa c c coa c c a o c c c c a o c c c c coa c c c c coenzyme h+ e c o a c o a a o c h+ e n c c c c n h2 n h2 coenzyme h+ e tca cycle coenzyme c carbon dioxide c carbon dioxide h+ e coenzyme h+ h+ h+ h+ electron transport chain coenzyme h+ e a p p a p p p h+ h+ + oxygen h2o 232 chapter 7 people can enjoy bountiful meals such as this without storing body fat, provided that they expend as much energy as they take in. -t i d e o t o h p / g r e b n e e r g f f e j some people, however, eat too much or exercise too little and get fat; others eat too little or exercise too much and get thin. -the metabolic details have already been de- scribed; the next sections review them from the perspective of the body fat gained or lost. -the possible reasons why people gain or lose weight are explored in chapter 8. feasting excess energy when a person eats too much, metabolism favors fat formation. -fat cells enlarge re- gardless of whether the excess in kcalories derives from protein, carbohydrate, or fat. -the pathway from dietary fat to body fat, however, is the most direct (requiring only a few metabolic steps) and the most efficient (costing only a few kcalories). -to con- vert a dietary triglyceride to a triglyceride in adipose tissue, the body removes two of the fatty acids from the glycerol backbone, absorbs the parts, and puts them (and others) together again. -by comparison, to convert a molecule of sucrose, the body has to split glucose from fructose, absorb them, dismantle them to pyruvate and acetyl coa, assemble many acetyl coa molecules into fatty acid chains, and finally attach fatty acids to a glycerol backbone to make a triglyceride for storage in adi- pose tissue. -quite simply, the body uses much less energy to convert dietary fat to body fat than it does to convert dietary carbohydrate to body fat. -on average, stor- ing excess energy from dietary fat as body fat uses only 5 percent of the ingested en- ergy intake, but storing excess energy from dietary carbohydrate as body fat requires 25 percent of the ingested energy intake. -the pathways from excess protein and excess carbohydrate to body fat are not only indirect and inefficient, but they are also less preferred by the body (having other priorities for using these nutrients). -before entering fat storage, protein must first tend to its many roles in the body s lean tissues, and carbohydrate must fill the glycogen stores. -simply put, using these two nutrients to make fat is a low priority for the body. -still, if eaten in abundance, any of the energy-yielding nutrients can be made into fat. -this chapter has described each of the energy-yielding nutrients individually, but cells use a mixture of these fuels. -how much of which nutrient is in the fuel mix depends, in part, on its availability from the diet. -(the proportion of each fuel also depends on physical activity, as chapter 14 explains.) -dietary protein and dietary carbohydrate influence the mixture of fuel used during energy metabolism. -usu- ally, protein s contribution to the fuel mix is relatively minor and fairly constant, but protein oxidation does increase when protein is eaten in excess. -similarly, car- bohydrate eaten in excess significantly enhances carbohydrate oxidation. -in con- trast, fat oxidation does not respond to dietary fat intake, especially when dietary changes occur abruptly. -the more protein or carbohydrate in the fuel mix, the less fat contributes to the fuel mix. -instead of being oxidized, fat accumulates in stor- age. -details follow. -excess protein recall from chapter 6 that the body cannot store excess amino acids as such; it has to convert them to other compounds. -contrary to popular opin- ion, a person cannot grow muscle simply by overeating protein. -lean tissue such as muscle develops in response to a stimulus such as hormones or physical activity. -when a person overeats protein, the body uses the surplus first by replacing normal daily losses and then by increasing protein oxidation. -the body achieves protein balance this way, but any increase in protein oxidation displaces fat in the fuel mix. -any additional protein is then deaminated and the remaining carbons are used to make fatty acids, which are stored as triglycerides in adipose tissue. -thus a person can grow fat by eating too much protein. -people who eat huge portions of meat and other protein-rich foods may wonder why they have weight problems. -not only does the fat in those foods lead to fat storage, but the protein can, too, when energy intake exceeds energy needs. -many fad weight-loss diets encourage high protein intakes based on the false assumption that protein builds only muscle, not fat (see highlight 9 for more details). -metabolism: transformations and interactions 233 excess carbohydrate compared with protein, the proportion of carbohydrate in the fuel mix changes more dramatically when a person overeats. -the body handles abundant carbohydrate by first storing it as glycogen, but glycogen storage areas are limited and fill quickly. -because maintaining glucose balance is critical, the body uses glucose frugally when the diet provides only small amounts and freely when stores are abundant. -in other words, glucose oxidation rapidly adjusts to the dietary intake of carbohydrate. -excess glucose can also be converted to fat directly, but this is a minor pathway.6 as mentioned earlier, converting glucose to fat is energetically expensive and does not occur until after glycogen stores have been filled. -even then, only a little, if any, new fat is made from carbohydrate.7 nevertheless, excess dietary carbohydrate can lead to weight gain when it dis- places fat in the fuel mix. -when this occurs, carbohydrate spares both dietary fat and body fat from oxidation an effect that may be more pronounced in over- weight people than in lean people.8 the net result: excess carbohydrate contributes to obesity or at least to the maintenance of an overweight body. -excess fat unlike excess protein and carbohydrate, which both enhance their own oxidation, eating too much fat does not promote fat oxidation.9 instead, excess dietary fat moves efficiently into the body s fat stores; almost all of the excess is stored. -in summary if energy intake exceeds the body s energy needs, the result will be weight gain regardless of whether the excess intake is from protein, carbohydrate, or fat. -the difference is that the body is much more efficient at storing energy when the excess derives from dietary fat. -the transition from feasting to fasting figure 7-22 (p. 234) shows the metabolic pathways operating in the body as it shifts from feasting (part a) to fasting (parts b and c). -after a meal, glucose, glycerol, and fatty acids from foods are used as needed and then stored. -later, as the body shifts from a fed state to a fasting one, it begins drawing on these stores. -glycogen and fat are released from storage to provide more glucose, glycerol, and fatty acids for energy. -energy is needed all the time. -even when a person is asleep and totally relaxed, the cells of many organs are hard at work. -in fact, this work the cells work that maintains all life processes without any conscious effort represents about two- thirds of the total energy a person spends in a day. -the small remainder is the work that a person s muscles perform voluntarily during waking hours. -the body s top priority is to meet the cells needs for energy, and it normally does this by periodic refueling that is, by eating several times a day. -when food is not available, the body turns to its own tissues for other fuel sources. -if people choose not to eat, we say they are fasting; if they have no choice, we say they are starving. -the body makes no such distinction. -in either case, the body is forced to draw on its reserves of carbohydrate and fat and, within a day or so, on its vital protein tissues as well. -fasting inadequate energy during fasting, carbohydrate, fat, and protein are all eventually used for energy fuel must be delivered to every cell. -as the fast begins, glucose from the liver s stored glycogen and fatty acids from the adipose tissue s stored fat are both flowing into the cells work that maintains all life processes refers to the body s basal metabolism, which is described in chapter 8. liver and muscle glycogen stores body fat stores loss of nitrogen in urine (urea) body proteins energy for the brain, nervous system, and red blood cells energy for other cells 234 chapter 7 figure 7-22 feasting and fasting component to be broken down: broken down in the body to: and then used for: a. when a person overeats (feasting): when a person eats in excess of energy needs, the body stores a small amount of glycogen and much larger quantities of fat. -carbohydrate glucose fat fatty acids protein amino acids b. when a person draws on stores (fasting): when nutrients from a meal are no longer available to provide energy (about 2 to 3 hours after a meal), the body draws on its glycogen and fat stores for energy. -c. if the fast continues beyond glycogen depletion: as glycogen stores dwindle (after about 24 hours of starvation), the body begins to break down its protein (muscle and lean tissue) to amino acids to synthesize glucose needed for brain and nervous system energy. -in addition, the liver converts fats to ketone bodies, which serve as an alternative energy source for the brain, thus slowing the breakdown of body protein. -liver and muscle glycogen stores* glucose body fat stores fatty acids body protein body fat loss of nitrogen in urine (urea) glucose ketone bodies energy for the brain and nervous system energy for other cells amino acids fatty acids *the muscles stored glycogen provides glucose only for the muscle in which the glycogen is stored. -cells, then breaking down to yield acetyl coa, and finally delivering energy to power the cells work. -several hours later, however, most of the glucose is used up liver glycogen is exhausted and blood glucose begins to fall. -low blood glucose serves as a signal that promotes further fat breakdown and release of amino acids from muscles. -glucose needed for the brain at this point, most of the cells are depending on fatty acids to continue providing their fuel. -but red blood cells and the cells of the nervous system need glucose. -glucose is their primary energy fuel, and even when other energy fuels are available, glucose must be present to permit the energy- metabolizing machinery of the nervous system to work. -normally, the brain and nerve cells which weigh only about three pounds consume about half of the to- tal glucose used each day (about 500 kcalories worth). -about one-fourth of the en- ergy the adult body uses when it is at rest is spent by the brain; in children, it can be up to one-half. -protein meets glucose needs the red blood cells and brain s special require- ments for glucose pose a problem for the fasting body. -the body can use its stores of fat, which may be quite generous, to furnish most of its cells with energy, but the red blood cells are completely dependent on glucose, and the brain and nerves prefer energy in the form of glucose. -amino acids that yield pyruvate can be used to make glucose, and to obtain the amino acids, body proteins must be broken down. -for this reason, body protein tissues such as muscle and liver always break down to some ex- tent during fasting. -the amino acids that can t be used to make glucose are used as an energy source for other body cells. -the breakdown of body protein is an expensive way to obtain glucose. -in the first few days of a fast, body protein provides about 90 percent of the needed glu- red blood cells contain no mitochondria. -review figure 7-1 (p. 214) to fully appreciate why red blood cells must depend on glucose for energy. -metabolism: transformations and interactions 235 reminder: ketone bodies are compounds pro- duced during the incomplete breakdown of fat when glucose is not available. -cose; glycerol, about 10 percent. -if body protein losses were to continue at this rate, death would ensue within three weeks, regardless of the quantity of fat a person had stored. -fortunately, fat breakdown also increases with fasting in fact, fat breakdown almost doubles, providing energy for other body cells and glycerol for glucose production. -the shift to ketosis as the fast continues, the body finds a way to use its fat to fuel the brain. -it adapts by combining acetyl coa fragments derived from fatty acids to produce an alternate energy source, ketone bodies (figure 7-23). -normally pro- duced and used only in small quantities, ketone bodies can provide fuel for some brain cells. -ketone body production rises until, after about ten days of fasting, it is meeting much of the nervous system s energy needs. -still, many areas of the brain rely exclusively on glucose, and to produce it, the body continues to sacrifice pro- tein albeit at a slower rate than in the early days of fasting. -when ketone bodies contain an acid group (cooh), they are called keto acids. -small amounts of keto acids are a normal part of the blood chemistry, but when their concentration rises, the ph of the blood drops. -this is ketosis, a sign that the body s chemistry is going awry. -elevated blood ketones (ketonemia) are excreted in the urine (ketonuria). -a fruity odor on the breath (known as acetone breath) devel- ops, reflecting the presence of the ketone acetone. -suppression of appetite ketosis also induces a loss of appetite. -as starvation continues, this loss of appetite becomes an advantage to a person without access to food, because the search for food would be a waste of energy. -when the person finds food and eats again, the body shifts out of ketosis, the hunger center gets the message that food is again available, and the appetite returns. -highlight 9 includes a discus- sion of the risks of ketosis-producing diets in its review of popular weight-loss diets. -slowing of metabolism in an effort to conserve body tissues for as long as pos- sible, the hormones of fasting slow metabolism. -as the body shifts to the use of ke- tone bodies, it simultaneously reduces its energy output and conserves both its fat and its lean tissue. -still the lean (protein-containing) organ tissues shrink in mass and perform less metabolic work, reducing energy expenditures. -as the muscles waste, they can do less work and so demand less energy, reducing expenditures fur- ther. -although fasting may promote dramatic weight loss, a low-kcalorie diet better supports fat loss while retaining lean tissue. -figure 7-23 ketone body formation 1 2 3 the first step in the formation of ketone bodies is the condensation of two molecules of acetyl coa and the removal of the coa to form a compound that is converted to the first ketone body. -this ketone body may lose a molecule of carbon dioxide to become another ketone. -or, the acetoacetate may add two hydrogens, becoming another ketone body (beta-hydroxybutyrate). -see appendix c for more details. -h o h o h c c coa + h c c coa + h2o h h acetyl coa acetyl coa 2 coa h o h o h c c c c oh h h a ketone, acetoacetate co2 h o h h c c c h h h a ketone, acetone 236 chapter 7 symptoms of starvation the adaptations just described slowing of energy output and reduction in fat loss occur in the starving child, the hungry homeless adult, the fasting religious person, the adolescent with anorexia nervosa, and the malnourished hospital patient. -such adaptations help to prolong their lives and ex- plain the physical symptoms of starvation: wasting; slowed heart rate, respiration, and metabolism; lowered body temperature; impaired vision; organ failure; and re- duced resistance to disease.10 psychological effects of food deprivation include de- pression, anxiety, and food-related dreams. -the body s adaptations to fasting are sufficient to maintain life for a long time up to two months. -mental alertness need not be diminished, and even some phys- ical energy may remain unimpaired for a surprisingly long time. -these remarkable adaptations, however, should not prevent anyone from recognizing the very real hazards that fasting presents. -in summary when fasting, the body makes a number of adaptations: increasing the break- down of fat to provide energy for most of the cells, using glycerol and amino acids to make glucose for the red blood cells and central nervous system, pro- ducing ketones to fuel the brain, suppressing the appetite, and slowing metab- olism. -all of these measures conserve energy and minimize losses. -this chapter has probed the intricate details of metabolism at the level of the cells, exploring the transformations of nutrients to energy and to storage compounds. -sev- eral chapters and highlights build on this information. -the highlight that follows this chapter shows how alcohol disrupts normal metabolism. -chapter 8 describes how a person s intake and expenditure of energy are reflected in body weight and body com- position. -chapter 9 examines the consequences of unbalanced energy budgets over- weight and underweight. -chapter 10 shows the vital roles the b vitamins play as coenzymes assisting all the metabolic pathways described here. -and chapter 14 revis- its metabolism to show how it supports the work of physically active people and how athletes can best apply that information in their choices of foods to eat. -www.thomsonedu.com/thomsonnow nutrition portfolio all day, every day, your cells dismantle carbohydrates, fats, and proteins, with the help of vitamins, minerals, and water, releasing energy to meet your body s immediate needs or storing it as fat for later use. -describe what types of foods best support aerobic and anaerobic activities. -consider whether you eat more protein, carbohydrate, or fat than your body needs. -explain how a low-carbohydrate diet forces your body into ketosis. -study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -1. define metabolism, anabolism, and catabolism; give an example of each. -(pp. -213 216) these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -2. name one of the body s high-energy molecules, and describe how it is used. -(pp. -216 217) 3. what are coenzymes, and what service do they provide 4. the pathway from pyruvate to acetyl coa: metabolism: transformations and interactions 237 in metabolism? -(p. 216) 4. name the four basic units, derived from foods, that are used by the body in metabolic transformations. -how many carbons are in the backbones of each? -(pp. -217 218) 5. define aerobic and anaerobic metabolism. -how does insufficient oxygen influence metabolism? -(pp. -220 221) 6. how does the body dispose of excess nitrogen? -(pp. -225 227) 7. summarize the main steps in the metabolism of glucose, glycerol, fatty acids, and amino acids. -(pp. -226 228) 8. describe how a surplus of the three energy nutrients contributes to body fat stores. -(pp. -219 226) 9. what adaptations does the body make during a fast? -what are ketone bodies? -define ketosis. -(pp. -233 236) 10. distinguish between a loss of fat and a loss of weight, and describe how each might happen. -(pp. -235 236) these multiple choice questions will help you prepare for an exam. -answers can be found below. -1. hydrolysis is an example of a(n): a. coupled reaction. -b. anabolic reaction. -c. catabolic reaction. -d. synthesis reaction. -2. during metabolism, released energy is captured and transferred by: a. enzymes. -b. pyruvate. -c. acetyl coa. -d. adenosine triphosphate. -3. glycolysis: a. requires oxygen. -b. generates abundant energy. -c. converts glucose to pyruvate. -d. produces ammonia as a by-product. -a. produces lactate. -b. is known as gluconeogenesis. -c. is metabolically irreversible. -d. requires more energy than it produces. -5. for complete oxidation, acetyl coa enters: a. glycolysis. -b. the tca cycle. -c. the cori cycle. -d. the electron transport chain. -6. deamination of an amino acid produces: a. vitamin b6 and energy. -b. pyruvate and acetyl coa. -c. ammonia and a keto acid. -d. carbon dioxide and water. -7. before entering the tca cycle, each of the energy- yielding nutrients is broken down to: a. ammonia. -b. pyruvate. -c. electrons. -d. acetyl coa. -8. the body stores energy for future use in: a. proteins. -b. acetyl coa. -c. triglycerides. -d. ketone bodies. -9. during a fast, when glycogen stores have been depleted, the body begins to synthesize glucose from: a. acetyl coa. -b. amino acids. -c. fatty acids. -d. ketone bodies. -10. during a fast, the body produces ketone bodies by: a. hydrolyzing glycogen. -b. condensing acetyl coa. -c. transaminating keto acids. -d. converting ammonia to urea. -references 1. r. h. garrett and c. m. grisham, biochem- istry (belmont, calif.: thomson brooks/ cole, 2005), p. 73. -2. r. a. robergs, f. ghiasvand, and d. parker, biochemistry of exercise-induced metabolic acidosis, american journal of physiology- regulatory, integrative and comparative physi- ology 287 (2004): r502-r516. -3. t. h. pederson and coauthors, intracellular acidosis enhances the excitability of work- ing muscle, science 305 (2004): 1144-1147. -4. s. s. gropper, j. l. smith, and j. l. groff, advanced nutrition and human metabolism (belmont, calif.: wadsworth/thomson learning, 2005), p. 198. answers 5. garrett and grisham, 2005, p. 669. -6. m. k. hellerstein, no common energy currency: de novo lipogenesis as the road less traveled, american journal of clinical nutrition 74 (2001): 707-708. -7. r. m. devitt and coauthors, de novo lipoge- nesis during controlled overfeeding with sucrose or glucose in lean and obese women, american journal of clinical nutrition 74 (2001): 707-708. -8. i. marques-lopes and coauthors, postpran- dial de novo lipogenesis and metabolic changes induced by a high-carbohydrate, low-fat meal in lean and overweight men, american journal of clinical nutrition 73 (2001): 253-261. -9. e. j. parks, macronutrient metabolism group symposium on dietary fat: how low should we go? -changes in fat synthesis influenced by dietary macronutrient con- tent, proceedings of the nutrition society 61 (2002): 281-286. -10. c. a. jolly, dietary restriction and immune function, journal of nutrition 134 (2004): 1853-1856. study questions (multiple choice) 1. c 9. b 2. d 3. c 4. c 5. b 6. c 7. d 8. c 10. b highlight 7 alcohol and nutrition with the understanding of metabolism gained from chapter 7, you are in a position to understand how the body handles alcohol, how alcohol interferes with metabolism, and how alcohol impairs health and nutrition. -be- fore examining alcohol s damaging effects, it may be appropriate to mention that drinking alcohol in moderation may have some health benefits, including reduced risks of heart at- tacks, strokes, dementia, diabetes, and osteoporosis.1 moderate alcohol consumption may lower mortality from all causes, but only in adults age 35 and older.2 no health benefits are evident before middle age.3 importantly, any benefits of alcohol must be weighed against the many harmful effects described in this high- light, as well as the possibility of alcohol abuse. -alcohol in beverages to the chemist, alcohol refers to a class of organic compounds containing hydroxyl (oh) groups (the accompanying glossary defines alcohol and related terms). -the glycerol to which fatty acids are attached in triglycerides is an example of an alcohol to a chemist. -to most people, though, alcohol refers to the intoxicat- ing ingredient in beer, wine, and distilled liquor (hard liquor). -the chemist s name for this particular alcohol is ethyl al- cohol, or ethanol. -glycerol has 3 carbons with 3 hydroxyl groups attached; ethanol has only 2 carbons and 1 hydroxyl group (see figure h7-1). -the remainder of this highlight talks about the par- ticular alcohol, ethanol, but refers to it simply as alcohol. -alcohols affect living things profoundly, partly because they act as lipid solvents. -their ability to dissolve lipids out of cell mem- branes allows alcohols to penetrate rapidly into cells, destroying cell structures and thereby killing the cells. -for this reason, most figure h7-1 two alcohols: glycerol and ethanol h h h h c oh c oh c oh h h ch ch h h oh glycerol is the alcohol used to make triglycerides. -ethanol is the alcohol in beer, wine, and distilled liquor. -238 alcohols are toxic in relatively small amounts; by the same token, because they kill microbial cells, they are useful as disinfectants. -s e g a m i y t t e g / y e l k n u d d r a h c i r ethanol is less toxic than the other alco- hols. -sufficiently diluted and taken in small enough doses, its action in the brain produces an effect that people seek not with zero risk, but with a low enough risk (if the doses are low enough) to be tolerable. -used in this way, alcohol is a drug that is, a substance that modifies body func- tions. -like all drugs, alcohol both offers benefits and poses haz- ards. -the 2005 dietary guidelines advise those who choose to drink alcoholic beverages to do so sensibly and in moderation. -dietary guidelines for americans 2005 those who choose to drink alcoholic beverages should do so sensibly and in moderation: up to one drink per day for women and two drinks per day for men. -alcoholic beverages should not be consumed by some individuals, including those who cannot restrict their alcohol intake, women of childbearing age who may become pregnant, pregnant and lactating women, children and ado- lescents, individuals taking medications that can interact with alcohol, and those with specific medical conditions. -alcoholic beverages should be avoided by individuals engag- ing in activities that require attention, skill, or coordination, such as driving or operating machinery. -the term moderation is important when describing alcohol use. -how many drinks constitute moderate use, and how much is a drink ? -first, a drink is any alcoholic beverage that delivers 1/2 ounce of pure ethanol: 5 ounces of wine 10 ounces of wine cooler 12 ounces of beer 11/2 ounces of distilled liquor (80 proof whiskey, scotch, rum, or vodka) beer, wine, and liquor deliver different amounts of alcohol. -the amount of alcohol in distilled liquor is stated as proof: 100 proof liquor is 50 percent alcohol, 80 proof is 40 percent alcohol, and so forth. -wine and beer have less alcohol than distilled liquor, although some fortified wines and beers have more alcohol than the regular va- rieties (see photo caption on p. 239). -alcohol and nutrition 239 g lossary acetaldehyde (ass-et-al-duh- hide): an intermediate in alcohol metabolism. -alcohol: a class of organic compounds containing hydroxyl (oh) groups. -alcohol abuse: a pattern of drinking that includes failure to fulfill work, school, or home responsibilities; drinking in situations that are physically dangerous (as in driving while intoxicated); recurring alcohol- related legal problems (as in aggravated assault charges); or continued drinking despite ongoing social problems that are caused by or worsened by alcohol. -alcohol dehydrogenase (dee- high-droj-eh-nayz): an enzyme active in the stomach and the liver that converts ethanol to acetaldehyde. -alcoholism: a pattern of drinking that includes a strong craving for alcohol, a loss of control and an inability to stop drinking once begun, withdrawal symptoms (nausea, sweating, shakiness, and anxiety) after heavy drinking, and the need for increasing amounts of alcohol to feel high. -antidiuretic hormone (adh): a 11 2 oz of hard liquor (80 proof hormone produced by the pituitary gland in response to dehydration (or a high sodium concentration in the blood). -it stimulates the kidneys to reabsorb more water and therefore prevents water loss in urine (also called vasopressin). -(this adh should not be confused with the enzyme alcohol dehydrogenase, which is also sometimes abbreviated adh.) -beer: an alcoholic beverage brewed by fermenting malt and hops. -cirrhosis (seer-oh-sis): advanced liver disease in which liver cells turn orange, die, and harden, permanently losing their function; often associated with alcoholism. -cirrhos (cid:2) an orange distilled liquor or hard liquor: an alcoholic beverage made by fermenting and distilling grains; sometimes called distilled spirits. -drink: a dose of any alcoholic beverage that delivers 1 2 oz of pure ethanol: 5 oz of wine 10 oz of wine cooler 12 oz of beer whiskey, scotch, rum, or vodka) drug: a substance that can modify one or more of the body s functions. -ethanol: a particular type of alcohol found in beer, wine, and distilled liquor; also called ethyl alcohol (see figure h7-1). -ethanol is the most widely used and abused drug in our society. -it is also the only legal, nonprescription drug that produces euphoria. -fatty liver: an early stage of liver deterioration seen in several diseases, including kwashiorkor and alcoholic liver disease. -fatty liver is characterized by an accumulation of fat in the liver cells. -fibrosis (fye-broh-sis): an intermediate stage of liver deterioration seen in several diseases, including viral hepatitis and alcoholic liver disease. -in fibrosis, the liver cells lose their function and assume the characteristics of connective tissue cells (fibers). -meos or microsomal (my-krow- so-mal) ethanol-oxidizing system: a system of enzymes in the liver that oxidize not only alcohol but also several classes of drugs. -moderation: in relation to alcohol consumption, not more than two drinks a day for the average-size man and not more than one drink a day for the average-size woman. -nad (nicotinamide adenine dinucleotide): the main coenzyme form of the vitamin niacin. -its reduced form is nadh. -narcotic (nar-kot-ic): a drug that dulls the senses, induces sleep, and becomes addictive with prolonged use. -proof: a way of stating the percentage of alcohol in distilled liquor. -liquor that is 100 proof is 50% alcohol; 90 proof is 45%, and so forth. -wernicke-korsakoff (ver-nee-key kore-sah-kof) syndrome: a neurological disorder typically associated with chronic alcoholism and caused by a deficiency of the b vitamin thiamin; also called alcohol- related dementia. -wine: an alcoholic beverage made by fermenting grape juice. -12 oz beer 10 oz wine cooler 2 1 oz liquor 1 (80 proof whiskey, gin, brandy, rum, vodka) . -c n i , s o i d u t s a r a l o p 5 oz wine each of these servings equals one drink. -second, because people have different tolerances for alcohol, it is impossible to name an exact daily amount of alcohol that is appro- priate for everyone. -authorities have attempted to identify amounts that are acceptable for most healthy people. -an accepted definition of moderation is up to two drinks per day for men and up to one o i g g u r r a f w e h t t a m wines contain 7 to 24 percent alcohol by volume; those contain- ing 14 percent or more must state their alcohol content on the label, whereas those with less than 14 percent may simply state table wine or light wine. -beers typically contain less than 5 percent alcohol by volume and malt liquors, 5 to 8 percent; regu- lations vary, with some states requiring beer labels to show the alcohol content and others prohibiting such statements. -drink per day for women. -(pregnant women are advised to abstain from alcohol, as highlight 15 explains.) -notice that this advice is 240 highlight 7 stated as a maximum, not as an average; seven drinks one night a week would not be considered moderate, even though one a day would be. -doubtless some people could consume slightly more; others could not handle nearly so much without risk. -the amount a person can drink safely is highly individual, depending on genetics, health, gender, body composition, age, and family history. -alcohol in the body from the moment an alcoholic beverage enters the body, alcohol is treated as if it has special privileges. -unlike foods, which require time for digestion, alcohol needs no digestion and is quickly ab- sorbed across the walls of an empty stomach, reaching the brain within a few minutes. -consequently, a person can immediately feel euphoric when drinking, especially on an empty stomach. -when the stomach is full of food, alcohol has less chance of touching the walls and diffusing through, so its influence on the brain is slightly delayed. -this information leads to a practical tip: eat snacks when drinking alcoholic beverages. -carbohydrate snacks slow alcohol absorption and high-fat snacks slow peristalsis, keep- ing the alcohol in the stomach longer. -salty snacks make a person thirsty; to quench thirst, drink water instead of more alcohol. -the stomach begins to break down alcohol with its alcohol de- hydrogenase enzyme. -women produce less of this stomach en- zyme than men; consequently, more alcohol reaches the intestine for absorption into the bloodstream. -as a result, women absorb more alcohol than men of the same size who drink the same amount of alcohol. -consequently, they are more likely to become more intoxicated on less alcohol than men. -such differences be- tween men and women help explain why women have a lower al- cohol tolerance and a lower recommendation for moderate intake. -in the small intestine, alcohol is rapidly absorbed. -from this point on, alcohol receives priority treatment: it gets absorbed and metabolized before most nutrients. -alcohol s priority status helps to ensure a speedy disposal and reflects two facts: alcohol cannot be stored in the body, and it is potentially toxic. -alcohol arrives in the liver the capillaries of the digestive tract merge into veins that carry the alcohol-laden blood to the liver. -these veins branch and re- branch into capillaries that touch every liver cell. -liver cells are the only other cells in the body that can make enough of the alcohol dehydrogenase enzyme to oxidize alcohol at an appreciable rate. -the routing of blood through the liver cells gives them the chance to dispose of some alcohol before it moves on. -alcohol affects every organ of the body, but the most dramatic evidence of its disruptive behavior appears in the liver. -if liver cells could talk, they would describe alcohol as demanding, egocen- tric, and disruptive of the liver s efficient way of running its busi- ness. -for example, liver cells normally prefer fatty acids as their fuel, and they like to package excess fatty acids into triglycerides and ship them out to other tissues. -when alcohol is present, how- ever, the liver cells are forced to metabolize alcohol and let the fatty acids accumulate, sometimes in huge stockpiles. -alcohol metabolism can also permanently change liver cell structure, im- pairing the liver s ability to metabolize fats. -as a result, heavy drinkers develop fatty livers. -the liver is the primary site of alcohol metabolism.4 it can process about 1/2 ounce of ethanol per hour (the amount in a typ- ical drink), depending on the person s body size, previous drink- ing experience, food intake, and general health. -this maximum rate of alcohol breakdown is set by the amount of alcohol dehy- drogenase available. -if more alcohol arrives at the liver than the enzymes can handle, the extra alcohol travels to all parts of the body, circulating again and again until liver enzymes are finally available to process it. -another practical tip derives from this in- formation: drink slowly enough to allow the liver to keep up no more than one drink per hour. -the amount of alcohol dehydrogenase enzyme present in the liver varies with individuals, depending on the genes they have in- herited and on how recently they have eaten. -fasting for as little as a day forces the body to degrade its proteins, including the al- cohol-processing enzymes, and this can slow the rate of alcohol metabolism by half. -drinking after not eating all day thus causes the drinker to feel the effects more promptly for two reasons: rapid absorption and slowed breakdown. -by maintaining higher blood alcohol concentrations for longer times, alcohol can anesthetize the brain more completely (as described later in this highlight). -the alcohol dehydrogenase enzyme breaks down alcohol by removing hydrogens in two steps. -(figure h7-2 provides a simpli- fied diagram of alcohol metabolism; appendix c provides the chemical details.) -in the first step, alcohol dehydrogenase oxi- dizes alcohol to acetaldehyde. -high concentrations of acetalde- hyde in the brain and other tissues are responsible for many of the damaging effects of alcohol abuse. -figure h7-2 alcohol metabolism nad+ nadh + h+ nad+ nadh + h+ alcohol (ethanol) acetaldehyde acetate acetyl coa alcohol dehydrogenase acetaldehyde dehydrogenase coa the conversion of alcohol to acetyl coa requires the b vitamin niacin in its role as the coenzyme nad. -when the enzymes oxidize alcohol, they remove h atoms and attach them to nad. -thus nad is used up and nadh accumulates. -(note: more accurately, nad+ is converted to nadh + h+.) -figure h7-3 alternate route for acetyl coa: to fat alcohol and nutrition 241 fat (triglycerides) fatty acids nad+ nadh + h+ nad+ nadh + h+ alcohol (ethanol) acetaldehyde acetate acetyl coa alcohol dehydrogenase acetaldehyde dehydrogenase coa acetyl coa molecules are blocked from getting into the tca cycle by the high level of nadh. -instead of being used for energy, the acetyl coa molecules become building blocks for fatty acids. -tca cycle in the second step, a related enzyme, acetaldehyde dehydro- genase, converts acetaldehyde to acetate, which is then con- verted to acetyl coa the crossroads compound introduced in chapter 7 that can enter the tca cycle to generate energy. -these reactions produce hydrogen ions (h+). -the b vitamin niacin, in its role as the coenzyme nad (nicotinamide adenine dinu- cleotide), helpfully picks up these hydrogen ions (becoming nadh). -thus, whenever the body breaks down alcohol, nad di- minishes and nadh accumulates. -(chapter 10 presents informa- tion on nad and the other coenzyme roles of the b vitamins.) -alcohol disrupts the liver during alcohol metabolism, the multitude of other metabolic processes for which nad is required, including glycolysis, the tca cycle, and the electron transport chain, falter. -its presence is sorely missed in these energy pathways because it is the chief car- rier of the hydrogens that travel with their electrons along the electron transport chain. -without adequate nad, these energy pathways cannot function. -traffic either backs up, or an alternate route is taken. -such changes in the normal flow of energy path- ways have striking physical consequences. -for one, the accumulation of hydrogen ions during alcohol me- tabolism shifts the body s acid-base balance toward acid. -for an- other, the accumulation of nadh slows the tca cycle, so pyruvate and acetyl coa build up. -excess acetyl coa then takes the route to fatty acid synthesis (as figure h7-3 illustrates), and fat clogs the liver. -as you might expect, a liver overburdened with fat cannot function properly. -liver cells become less efficient at performing a number of tasks. -much of this inefficiency impairs a person s nu- tritional health in ways that cannot be corrected by diet alone. -for example, the liver has difficulty activating vitamin d, as well as producing and releasing bile. -to overcome such problems, a person needs to stop drinking alcohol. -the synthesis of fatty acids accelerates with exposure to alco- hol. -fat accumulation can be seen in the liver after a single night of heavy drinking. -fatty liver, the first stage of liver deterioration seen in heavy drinkers, interferes with the distribution of nutrients and oxygen to the liver cells. -fatty liver is reversible with absti- nence from alcohol. -if fatty liver lasts long enough, however, the liver cells will die and form fibrous scar tissue. -this second stage of liver deterioration is called fibrosis. -some liver cells can regen- erate with good nutrition and abstinence from alcohol, but in the most advanced stage, cirrhosis, damage is the least reversible. -the fatty liver has difficulty generating glucose from protein. -without gluconeogenesis, blood glucose can plummet, leading to irreversible damage to the central nervous system. -the lack of glucose together with the overabundance of acetyl coa sets the stage for ketosis. -the body uses the acetyl coa to make ketone bodies; their acidity pushes the acid-base balance further toward acid and suppresses nervous system activity. -excess nadh also promotes the making of lactate from pyru- vate. -the conversion of pyruvate to lactate uses the hydrogens from nadh and restores some nad, but a lactate buildup has se- rious consequences of its own it adds still further to the body s acid burden and interferes with the excretion of another acid, uric acid, causing inflammation of the joints. -alcohol alters both amino acid and protein metabolism. -syn- thesis of proteins important in the immune system slows down, weakening the body s defenses against infection. -protein defi- ciency can develop, both from a diminished synthesis of protein and from a poor diet. -normally, the cells would at least use the amino acids from the protein foods a person eats, but the drinker s liver deaminates the amino acids and uses the carbon fragments primarily to make fat or ketones. -eating well does not protect the drinker from protein depletion; a person has to stop drinking alcohol. -the liver s priority treatment of alcohol affects its handling of drugs as well as nutrients. -in addition to the dehydrogenase enzyme 242 highlight 7 already described, the liver possesses an enzyme system that metab- olizes both alcohol and several other types of drugs. -called the meos (microsomal ethanol-oxidizing system), this system handles about one-fifth of the total alcohol a person consumes. -at high blood concentrations or with repeated exposures, alcohol stimulates the synthesis of enzymes in the meos. -the result is a more efficient metabolism of alcohol and tolerance to its effects. -as a person s blood alcohol rises, alcohol competes with and wins out over other drugs whose metabolism also relies on the meos. -if a person drinks and uses another drug at the same time, the meos will dispose of alcohol first and metabolize the drug more slowly. -while the drug waits to be handled later, the dose may build up so that its effects are greatly amplified sometimes to the point of being fatal. -in contrast, once a heavy drinker stops drinking and alcohol is no longer competing with other drugs, the enhanced meos me- tabolizes drugs much faster than before. -as a result, determining the correct dosages of medications can be challenging. -this discussion has emphasized the major way that the blood is cleared of alcohol metabolism by the liver but there is an- other way. -about 10 percent of the alcohol leaves the body through the breath and in the urine. -this is the basis for the breath and urine tests for drunkenness. -the amounts of alcohol in the breath and in the urine are in proportion to the amount still in the bloodstream and brain. -in nearly all states, legal drunken- ness is set at 0.10 percent or less, reflecting the relationship be- tween alcohol use and traffic and other accidents. -alcohol arrives in the brain alcohol is a narcotic. -people used it for centuries as an anesthetic because it can deaden pain. -but alcohol was a poor anesthetic be- cause one could never be sure how much a person would need and how much would be a fatal dose. -consequently, new, more predictable anesthetics have replaced alcohol. -nonetheless, alco- hol continues to be used today as a kind of social anesthetic to help people relax or to relieve anxiety. -people think that alcohol is a stimulant because it seems to relieve inhibitions. -actually, though, it accomplishes this by sedating inhibitory nerves, which are more numerous than excitatory nerves. -ultimately, alcohol acts as a depressant and affects all the nerve cells. -figure h7-4 de- scribes alcohol s effects on the brain. -it is lucky that the brain centers respond to a rising blood alco- hol concentration in the order described in figure h7-4 because a person usually passes out before managing to drink a lethal dose. -it is possible, though, to drink so fast that the effects of alcohol continue to accelerate after the person has passed out. -occasion- ally, a person dies from drinking enough to stop the heart before passing out. -table h7-1 shows the blood alcohol levels that corre- spond to progressively greater intoxication, and table h7-2 shows the brain responses that occur at these blood levels. -like liver cells, brain cells die with excessive exposure to alco- hol. -liver cells may be replaced, but not all brain cells can regen- erate. -thus some heavy drinkers suffer permanent brain damage. -figure h7-4 alcohol s effects on the brain 1 frontal lobe 2 midbrain 4 pons, medulla oblongata 3 cerebellum 1 2 3 4 judgment and reasoning centers are most sensitive to alcohol. -when alcohol flows to the brain, it first sedates the frontal lobe, the center of all conscious activity. -as the alcohol molecules diffuse into the cells of these lobes, they interfere with reasoning and judgment. -speech and vision centers in the midbrain are affected next. -if the drinker drinks faster than the rate at which the liver can oxidize the alcohol, blood alcohol concentrations rise: the speech and vision centers of the brain become sedated. -voluntary muscular control is then affected. -at still higher concentrations, the cells in the cerebellum responsible for coordination of voluntary muscles are affected, including those used in speech, eye-hand coordination, and limb movements. -at this point people under the influence stagger or weave when they try to walk, or they may slur their speech. -respiration and heart action are the last to be affected. -finally, the conscious brain is completely subdued, and the person passes out. -now the person can drink no more; this is fortunate because higher doses would anesthetize the deepest brain centers that control breathing and heartbeat, causing death. -alcohol and nutrition 243 table h7-1 alcohol doses and approximate blood level percentages for men and women drinksa body weight in pounds men drinksa body weight in pounds women 100 120 00 00 140 00 160 00 180 00 200 00 220 00 240 00 .04 .08 .11 .15 .19 .23 .26 .30 .34 .38 .03 .06 .09 .12 .16 .19 .22 .25 .28 .31 .03 .05 .08 .11 .13 .16 .19 .21 .24 .27 .02 .05 .07 .09 .12 .14 .16 .19 .21 .23 .02 .04 .06 .08 .11 .13 .15 .17 .19 .21 .02 .04 .06 .08 .09 .11 .13 .15 .17 .19 .02 .03 .05 .07 .09 .10 .12 .14 .15 .17 .02 .03 .05 .06 .08 .09 .11 .13 .14 .16 only safe driving limit impairment begins driving skills significantly affected legally intoxicated 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 90 100 00 00 120 00 140 00 160 00 180 00 200 00 220 240 00 00 .05 .10 .15 .20 .25 .30 .35 .40 .45 .51 .05 .09 .14 .18 .23 .27 .32 .36 .41 .45 .04 .08 .11 .15 .19 .23 .27 .30 .34 .38 .03 .07 .10 .13 .16 .19 .23 .26 .29 .32 .03 .06 .09 .11 .14 .17 .20 .23 .26 .28 .03 .05 .08 .10 .13 .15 .18 .20 .23 .25 .02 .05 .07 .09 .11 .14 .16 .18 .20 .23 .02 .04 .06 .08 .10 .12 .14 .17 .19 .21 .02 .04 .06 .08 .09 .11 .13 .15 .17 .19 only safe driving limit impairment begins driving skills significantly affected legally intoxicated note: in some states, driving under the influence is proved when an adult s blood contains 0.08 percent alcohol, and in others, 0.10. many states have adopted a zero-tolerance policy for drivers under age 21, using 0.02 percent as the limit. -ataken within an hour or so; each drink equivalent to 1 2 ounce pure ethanol. -source: national clearinghouse for alcohol and drug information table h7-2 alcohol blood levels and brain responses blood alcohol concentration effect on brain 0.05 0.10 0.15 0.20 0.30 impaired judgment, relaxed inhibitions, altered mood, increased heart rate impaired coordination, delayed reaction time, exaggerated emotions, impaired peripheral vision, impaired ability to operate a vehicle slurred speech, blurred vision, staggered walk, seriously impaired coordination and judgment double vision, inability to walk uninhibited behavior, stupor, confusion, inability to comprehend 0.40 to 0.60 unconsciousness, shock, coma, death (cardiac or respiratory failure) note: blood alcohol concentration depends on a number of factors, including alcohol in the beverage, the rate of consumption, the person s gender, and body weight. -for example, a 100- pound female can become legally drunk ((cid:3)0.10 concentration) by drinking three beers in an hour, whereas a 220-pound male consuming that amount at the same rate would have a 0.05 blood alcohol concentration. -whether alcohol impairs cognition in moderate drinkers is unclear.5 people who drink alcoholic beverages may notice that they urinate more, but they may be unaware of the vicious cycle that results. -alcohol depresses production of antidiuretic hormone (adh), a hormone produced by the pituitary gland that retains water consequently, with less adh, more water is lost. -loss of body water leads to thirst, and thirst leads to more drinking. -wa- ter will relieve dehydration, but the thirsty drinker may drink alco- hol instead, which only worsens the problem. -such information provides another practical tip: drink water when thirsty and be- fore each alcoholic drink. -drink an extra glass or two before go- ing to bed. -this strategy will help lessen the effects of a hangover. -water loss is accompanied by the loss of important minerals. -as chapters 12 and 13 explain, these minerals are vital to the body s fluid balance and to many chemical reactions in the cells, including muscle action. -detoxification treatment includes restoration of mineral balance as quickly as possible. -alcohol and malnutrition for many moderate drinkers, alcohol does not suppress food intake and may actually stimulate appetite. -moderate drinkers usually consume alcohol as added energy on top of their normal food intake. -in addition, alcohol in moderate doses is efficiently metab- olized. -consequently, alcohol can contribute to body fat and weight gain either by inhibiting oxidation or by being con- verted to fat.6 metabolically, alcohol is almost as efficient as fat in promoting obesity; each ounce of alcohol represents about a half- ounce of fat. -alcohol s contribution to body fat is most evident in the central obesity that commonly accompanies alcohol con- sumption, popularly and appropriately known as the beer belly. -7 alcohol in heavy doses, though, is not efficiently metabo- lized, generating more heat than fat. -heavy drinkers usually con- sume alcohol as substituted energy instead of their normal food intake. -they tend to eat poorly and suffer malnutrition. -alcohol is rich in energy (7 kcalories per gram), but as with pure sugar or fat, the kcalories are empty of nutrients. -the more alcohol people drink, the less likely that they will eat enough food to obtain adequate nutrients. -the more kcalories spent on alcohol, the fewer kcalories available to spend on nutritious foods. -table h7-3 (p. 244) shows the kcalorie amounts of typical alcoholic beverages. -chronic alcohol abuse not only displaces nutrients from the diet, but it also interferes with the body s metabolism of nutrients. -most dramatic is alcohol s effect on the b vitamin folate. -the liver loses its ability to retain folate, and the kidneys increase their excretion of it. -alcohol abuse creates a folate deficiency that devastates digestive 244 highlight 7 table h7-3 kcalories in alcoholic beverages and mixers amount (oz) energy (kcal) beverage beer regular light nonalcoholic distilled liquor (gin, rum, vodka, whiskey) 80 proof 86 proof 90 proof liqueurs coffee liqueur, 53 proof coffee and cream liqueur, 34 proof cr me de menthe, 72 proof mixers club soda cola cranberry juice cocktail diet drinks ginger ale or tonic grapefruit juice orange juice tomato or vegetable juice wine dessert nonalcoholic red or ros white wine cooler 12 12 12 11 2 11 2 11 2 11 2 11 2 11 2 12 12 8 12 12 8 8 8 31 2 8 31 2 31 2 12 150 78 131 32 82 100 105 110 175 155 185 0 150 145 2 125 95 110 45 110 135 14 75 70 170 system function. -the intestine normally releases and retrieves fo- late continuously, but it becomes damaged by folate deficiency and alcohol toxicity, so it fails to retrieve its own folate and misses any that may trickle in from food as well. -alcohol also interferes with the action of folate in converting the amino acid homocys- teine to methionine. -the result is an excess of homocysteine, which has been linked to heart disease, and an inadequate supply of methionine, which slows the production of new cells, espe- cially the rapidly dividing cells of the intestine and the blood. -the combination of poor folate status and alcohol consumption has also been implicated in promoting colorectal cancer. -the inadequate food intake and impaired nutrient absorption that accompany chronic alcohol abuse frequently lead to a defi- ciency of another b vitamin thiamin. -in fact, the cluster of thi- amin-deficiency symptoms commonly seen in chronic alcoholism has its own name the wernicke-korsakoff syndrome. -this syndrome is characterized by paralysis of the eye muscles, poor muscle coordination, impaired memory, and damaged nerves; it and other alcohol-related memory problems may respond to thi- amin supplements. -acetaldehyde, an intermediate in alcohol metabolism (review figure h7-2, p. 240), interferes with nutrient use, too. -for exam- ple, acetaldehyde dislodges vitamin b6 from its protective binding protein so that it is destroyed, causing a vitamin b6 deficiency and, thereby, lowered production of red blood cells. -malnutrition occurs not only because of lack of intake and al- tered metabolism but because of direct toxic effects as well. -alco- hol causes stomach cells to oversecrete both gastric acid and histamine, an immune system agent that produces inflammation. -beer in particular stimulates gastric acid secretion, irritating the linings of the stomach and esophagus and making them vulnera- ble to ulcer formation. -overall, nutrient deficiencies are virtually inevitable in alcohol abuse, not only because alcohol displaces food but also because al- cohol directly interferes with the body s use of nutrients, making them ineffective even if they are present. -intestinal cells fail to ab- sorb b vitamins, notably, thiamin, folate, and vitamin b12. -liver cells lose efficiency in activating vitamin d. cells in the retina of the eye, which normally process the alcohol form of vitamin a (retinol) to its aldehyde form needed in vision (retinal), find themselves process- ing ethanol to acetaldehyde instead. -likewise, the liver cannot con- vert the aldehyde form of vitamin a to its acid form (retinoic acid), which is needed to support the growth of its (and all) cells. -regardless of dietary intake, excessive drinking over a lifetime creates deficits of all the nutrients mentioned in this discussion and more. -no diet can compensate for the damage caused by heavy alcohol consumption. -alcohol s short-term effects the effects of abusing alcohol may be apparent immediately, or they may not become evident for years to come. -among the im- mediate consequences, all of the following involve alcohol use:8 one-quarter of all emergency-room admissions one-third of all suicides one-half of all homicides one-half of all domestic violence incidents one-half of all traffic fatalities one-half of all fire victim fatalities these statistics are sobering. -the consequences of heavy drinking touch all races and all segments of society men and women, young and old, rich and poor. -one group particularly hard hit by heavy drinking is college students not because they are prone to alcoholism, but because they live in an environment and are in a developmental stage of life in which heavy drinking is considered acceptable.9 heavy drinking or binge drinking (defined as at least four drinks in a row for women and five drinks in a row for men) is widespread on college campuses and poses serious health and so- cial consequences to drinkers and nondrinkers alike. -* 10 in fact, binge drinking can kill: the respiratory center of the brain be- comes anesthetized, and breathing stops. -acute alcohol intoxica- tion can cause coronary artery spasms, leading to heart attacks. -binge drinking is especially common among college students who live in a fraternity or sorority house, attend parties fre- quently, engage in other risky behaviors, and have a history of binge drinking in high school. -compared with nondrinkers or moderate drinkers, people who frequently binge drink (at least three times within two weeks) are more likely to engage in unpro- * this definition of binge drinking, without specification of time elapsed, is consistent with standard practice in alcohol research. -tected sex, have multiple sex partners, damage property, and as- sault others.11 on average, every day alcohol is involved in the:12 from all causes.15 excessive alcohol consumption is the third lead- ing preventable cause of death in the united states.16 alcohol and nutrition 245 death of 5 college students sexual assault of 266 college students injury of 1641 college students assault of 1907 college students binge drinkers skew the statistics on college students alcohol use. -the median number of drinks consumed by college students is 1.5 per week, but for binge drinkers, it is 14.5. nationally, only 20 percent of all students are frequent binge drinkers; yet they ac- count for two-thirds of all the alcohol students report consuming and most of the alcohol-related problems. -binge drinking is not limited to college campuses, of course, but it is most common among 18 to 24 year-olds.13 that age group and environment seem most accepting of such behavior despite its problems. -social acceptance may make it difficult for binge drinkers to recognize themselves as problem drinkers. -for this reason, interventions must focus both on educating individu- als and on changing the campus social environment.14 the dam- age alcohol causes only becomes worse if the pattern is not broken. -alcohol abuse sets in much more quickly in young people than in adults. -those who start drinking at an early age more of- ten suffer from alcoholism than people who start later on. -table h7-4 lists the key signs of alcoholism. -alcohol s long-term effects the most devastating long-term effect of alcohol is the damage done to a child whose mother abused alcohol during pregnancy. -the effects of alcohol on the unborn and the message that pregnant women should not drink alcohol are presented in highlight 15. for nonpregnant adults, a drink or two sets in motion many de- structive processes in the body, but the next day s abstinence reverses them. -as long as the doses are moderate, the time between them is ample, and nutrition is adequate, recovery is probably complete. -if the doses of alcohol are heavy and the time between them short, complete recovery cannot take place. -repeated onslaughts of alcohol gradually take a toll on all parts of the body (see table h7-5, p. 246). -compared with nondrinkers and moderate drinkers, heavy drinkers have significantly greater risks of dying table h7-4 signs of alcoholism personal strategies one obvious option available to people attending social gather- ings is to enjoy the conversation, eat the food, and drink nonalco- holic beverages. -several nonalcoholic beverages are available that mimic the look and taste of their alcoholic counterparts. -for those who enjoy champagne or beer, sparkling ciders and beers without alcohol are available. -instead of drinking a cocktail, a person can sip tomato juice with a slice of lime and a stalk of celery or just a plain cola beverage. -any of these drinks can ease conversation. -the person who chooses to drink alcohol should sip each drink slowly with food. -the alcohol should arrive at the liver cells slowly enough that the enzymes can handle the load. -it is best to space drinks, too, allowing about an hour or so to metabolize each drink. -if you want to help sober up a friend who has had too much to drink, don t bother walking arm in arm around the block. -walking muscles have to work harder, but muscle cells can t metabolize al- cohol; only liver cells can. -remember that each person has a lim- ited amount of the alcohol dehydrogenase enzyme that clears the blood at a steady rate. -time alone will do the job. -nor will it help to give your friend a cup of coffee. -caffeine is a stimulant, but it won t speed up alcohol metabolism. -the police say ruefully, if you give a drunk a cup of coffee, you ll just have a wide-awake drunk on your hands. -table h7-6 (p. 246) presents other alcohol myths. -people who have passed out from drinking need 24 hours to sober up completely. -let them sleep, but watch over them. -en- courage them to lie on their sides, instead of their backs. -that way, if they vomit, they won t choke. -don t drive too soon after drinking. -the lack of glucose for the brain s function and the length of time needed to clear the blood of alcohol make alcohol s adverse effects linger long after its blood concentration has fallen. -driving coordination is still im- paired the morning after a night of drinking, even if the drinking was moderate. -responsible aircraft pilots know that they must al- low 24 hours for their bodies to clear alcohol completely, and they refuse to fly any sooner. -the federal aviation administration and major airlines enforce this rule. -tolerance the person needs higher and higher intakes of alcohol to achieve intoxication withdrawal the person who stops drinking experiences anxiety, agitation, increased blood pressure, or seizures, or seeks alcohol to relieve these symptoms impaired control the person intends to have 1 or 2 drinks, but has 9 or 10 instead, or the person tries to control or quit drinking, but fails disinterest the person neglects important social, family, job, or school activities because of drinking time the person spends a great deal of time obtaining and drinking alcohol or recovering from excessive drinking impaired ability the person s intoxication or withdrawal symptoms interfere with work, school, or home problems the person continues drinking despite physical hazards or medical, legal, psychological, family, employment, or school problems the presence of three or more of these conditions is required to make a diagnosis. -source: adapted from diagnostic and statistical manual of mental disorders, 4th ed. -(washington, d.c.: american psychiatric association, 1994). -246 highlight 7 table h7-5 health effects of heavy alcohol consumption health problem effects of alcohol arthritis cancer increases the risk of inflamed joints increases the risk of cancer of the liver, pancreas, rectum, and breast; increases the risk of cancer of the lungs, mouth, pharynx, larynx, and esophagus, where alcohol interacts synergistically with tobacco fetal alcohol syndrome causes physical and behavioral abnormalities in the fetus (see highlight 15) heart disease hyperglycemia hypoglycemia infertility in heavy drinkers, raises blood pressure, blood lipids, and the risk of stroke and heart disease; when compared with those who abstain, heart disease risk is generally lower in light-to-moderate drinkers (see chapter 18) raises blood glucose lowers blood glucose, especially in people with diabetes increases the risks of menstrual disorders and spontaneous abortions (in women); suppresses luteinizing hormone (in women) and testosterone (in men) kidney disease enlarges the kidneys, alters hormone functions, and increases the risk of kidney failure liver disease malnutrition causes fatty liver, alcoholic hepatitis, and cirrhosis increases the risk of protein-energy malnutrition; low intakes of protein, calcium, iron, vitamin a, vitamin c, thiamin, vitamin b6, and riboflavin; and impaired absorption of calcium, phosphorus, vitamin d, and zinc nervous disorders causes neuropathy and dementia; impairs balance and memory obesity increases energy intake, but is not a primary cause of obesity psychological disturbances causes depression, anxiety, and insomnia note: this list is by no means all-inclusive. -alcohol has direct toxic effects on all body systems. -table h7-6 myths and truths concerning alcohol myth: truth: myth: truth: myth: truth: myth: truth: myth: truth: myth: truth: myth: truth: myth: truth: myth: truth: myth: truth: myth: truth: hard liquors such as rum, vodka, and tequila are more harmful than wine and beer. -the damage caused by alcohol depends largely on the amount consumed. -compared with hard liquor, beer and wine have relatively low percentages of alcohol, but they are often consumed in larger quantities. -consuming alcohol with raw seafood diminishes the likelihood of getting hepatitis. -people have eaten contaminated oysters while drinking alcoholic beverages and not gotten as sick as those who were not drinking. -but do not be misled: hepatitis is too serious an illness for anyone to depend on alcohol for protection. -alcohol stimulates the appetite. -for some people, alcohol may stimulate appetite, but it seems to have the opposite effect in heavy drinkers. -heavy drinkers tend to eat poorly and suffer malnutrition. -drinking alcohol is healthy. -moderate alcohol consumption is associated with a lower risk for heart disease (see chapter 18 for more details). -higher intakes, however, raise the risks for high blood pressure, stroke, heart disease, some cancers, accidents, violence, suicide, birth defects, and deaths in general. -furthermore, excessive alcohol consumption damages the liver, pancreas, brain, and heart. -no authority recommends that nondrinkers begin drinking alcoholic beverages to obtain health benefits. -wine increases the body s absorption of minerals. -wine may increase the body s absorption of potassium, calcium, phosphorus, magnesium, and zinc, but the alcohol in wine also promotes the body s excretion of these minerals, so no benefit is gained. -alcohol is legal and, therefore, not a drug. -alcohol is legal for adults 21 years old and older, but it is also a drug a substance that alters one or more of the body s functions. -a shot of alcohol warms you up. -alcohol diverts blood flow to the skin making you feel warmer, but it actually cools the body. -wine and beer are mild; they do not lead to alcoholism. -alcoholism is not related to the kind of beverage, but rather to the quantity and frequency of consumption. -mixing different types of drinks gives you a hangover. -too much alcohol in any form produces a hangover. -alcohol is a stimulant. -people think alcohol is a stimulant because it seems to relieve inhibitions, but it does so by depressing the activity of the brain. -alcohol is medically defined as a depressant drug. -beer is a great source of carbohydrate, vitamins, minerals, and fluids. -beer does provide some carbohydrate, but most of its kcalories come from alcohol. -the few vitamins and minerals in beer cannot compete with rich food sources. -and the diuretic effect of alcohol causes the body to lose more fluid in urine than is provided by the beer. -alcohol and nutrition 247 ethanol interferes with a multitude of chemical and hor- monal reactions in the body many more than have been enu- merated here. -with heavy alcohol consumption, the potential for harm is great. -the best way to escape the harmful effects of alcohol is, of course, to refuse alcohol altogether. -if you do drink alcoholic beverages, do so with care, and in moderation. -look again at the drawing of the brain in figure h7-4, and note that when someone drinks, judgment fails first. -judgment might tell a person to limit alcohol consumption to two drinks at a party, but if the first drink takes judgment away, many more drinks may follow. -the failure to stop drinking as planned, on re- peated occasions, is a danger sign warning that the person should not drink at all. -the accompanying nutrition on the net provides websites for organizations that offer information about alcohol and alcohol abuse. -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow, go to chapter 7, then to highlights nutrition on the net. -al-anon family support groups: www.al-anon.alateen.org find help for a family alcohol problem from alateen and search for alcohol at the u.s. government health site: www.healthfinder.gov gather information on alcohol and drug abuse from the find help for an alcohol or drug problem from alcoholics anonymous (aa) or narcotics anonymous: www.aa.org or www.wsoinc.com national clearinghouse for alcohol and drug information (ncadi): ncadi.samhsa.gov search for party to find tips for hosting a safe party from mothers against drunk driving (madd): www.madd.org learn more about alcoholism and drug dependence from the national council on alcoholism and drug depen- dence (ncadd): www.ncadd.org visit the national institute on alcohol abuse and alco- holism: www.collegedrinkingprevention.gov references 1. d. j. meyerhoff and coauthors, health risks of chronic moderate and heavy alcohol consumption: how much is too much? -alcoholism, clinical and experimental research 29 (2005): 1334-1340; j. b. standridge, r. g. zylstra, and s. m. adams, alcohol consump- tion: an overview of benefits and risks, southern medical journal 97 (2004): 664-672. -2. v. arndt and coauthors, age, alcohol con- sumption, and all-cause mortality, annals of epidemiology 14 (2004): 750-753. -3. j. connor and coauthors, the burden of death, disease, and disability due to alcohol in new zealand, new zealand medical journal 118 (2005): u1412. -4. l. e. nagy, molecular aspects of alcohol metabolism: transcription factors involved in early ethanol-induced liver injury, annual review of nutrition 24 (2004): 55-78. -5. d. krahn and coauthors, alcohol use and cognition at mid-life: the importance of adjusting for baseline cognitive ability and educational attainment, alcoholism: clinical and experimental research 27 (2003): 1162- 1166. -6. r. a. breslow and b. a. smothers, drinking patterns and body mass index in never smokers: national health interview survey, 1997-2001, american journal of epidemiology 161 (2005): 368-376; m. r. yeomans, effects of alcohol on food and energy intake in human subjects: evidence for passive and active over-consumption of energy, british journal of nutrition 92 (2004): s31-s34; s. g. wannamethee and a. g. shaper, alcohol, body weight, and weight gain in middle- aged men, american journal of clinical nutri- tion 77 (2003): 1312-1317; e. jequier, pathways to obesity, international journal of obesity and related metabolic disorders 26 (2002): s12-s17. -7. s. g. wannamethee, a. g. shaper, and p. h. whincup, alcohol and adiposity: effects of quantity and type of drink and time relation with meals, international journal of obesity and related metabolic disorders 29 (2005): 1436-1444; j. m. dorn and coauthors, alcohol drinking patterns differentially affect central adiposity as measured by abdominal height in women and men, journal of nutrition 133 (2003): 2655-2662. -8. position paper on drug policy: physician leadership on national drug policy (plndp), brown university center for alcohol and addiction studies, 2000. -9. a. m. brower, are college students alco- holics? -journal of american college health 50 (2002): 253-255. -10. r. d. brewer and m. h. swahn, binge drink- ing and violence, journal of the american medical association 294 (2005): 616-618; h. wechsler and coauthors, trends in college binge drinking during a period of increased prevention efforts findings from harvard school of public health college alcohol study surveys: 1993-2001, journal of ameri- can college health 50 (2002): 203-217. -11. wechsler and coauthors, 2002. -12. r. w. hingson and coauthors, magnitude of alcohol-related mortality and morbidity among u.s. college students ages 18-24: changes from 1998 to 2001, annual review of public health 26 (2005): 259-279. -13. national center for health statistics, chart- book on trends in the health of americans, alcohol consumption by adults 18 years of age and over, according to selected charac- teristics: united states, selected years 1997- 2003, (2005): 264-266. -14. a. ziemelis, r. b. bucknam, and a. m. elfessi, prevention efforts underlying de- creases in binge drinking at institutions of higher learning, journal of american college health 50 (2002): 238-252. -15. a. y. strandberg and coauthors, alcohol consumption, 29-y total mortality, and quality of life in men in old age, american journal of clinical nutrition 80 (2004): 1366- 1371; i. r. white, d. r. altmann, and k. nanchahal, alcohol consumption and mortality: modeling risks for men and women at different ages, british medical journal 325 (2002): 191-197. -16. centers for disease control, alcohol-attrib- utable deaths and years of potential life lost- united states, 2001, morbidity and mortality weekly report 53 (2004): 866-870. rosemary weller/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow how to: practice problems nutrition portfolio journal nutrition calculations: practice problems nutrition in your life it s a simple mathematical equation: energy in + energy out = energy balance. -the reality, of course, is much more complex. -one day you may devour a dozen doughnuts at midnight and sleep through your morning workout tipping the scales toward weight gain. -another day you may snack on veggies and train for this weekend s 10k race shifting the balance toward weight loss. -your body weight especially as it relates to your body fat and your level of fitness have consequences for your health. -so, how are you doing? -are you ready to see how your energy in and energy out balance and whether your body weight and fat measures are consistent with good health? -energy balance and body composition the body s remarkable machinery can cope with many extremes of diet. -as chapter 7 explained, both excess carbohydrate (glucose) and excess protein (amino acids) can contribute to body fat. -to some extent, amino acids can be used to make glucose. -to a very limited extent, even fat (the glycerol portion) can be used to make glucose. -but a grossly unbalanced diet imposes hardships on the body. -if energy intake is too low or if too lit- tle carbohydrate or protein is supplied, the body must degrade its own lean tissue to meet its glucose and protein needs. -if energy intake is too high, the body stores fat. -both excessive and deficient body fat result from an energy imbalance budgets. -the simple picture is as follows. -people who have consumed more food energy than they have expended bank the surplus as body fat. -to re- duce body fat, they need to expend more energy than they take in from food. -in contrast, people who have consumed too little food energy to sup- port their bodies activities have relied on their bodies fat stores and possi- bly some of their lean tissues as well. -to gain weight, these people need to take in more food energy than they expend. -as you will see, though, the details of the body s weight regulation are quite complex.1 this chapter de- scribes energy balance and body composition and examines the health problems associated with having too much or too little body fat. -the next chapter presents strategies toward resolving these problems. -energy balance people expend energy continuously and eat periodically to refuel. -ideally, their en- ergy intakes cover their energy expenditures without too much excess. -excess energy is stored as fat, and stored fat is used for energy between meals. -the amount of body fat a person deposits in, or withdraws from, storage on any given day depends on the energy balance for that day the amount consumed (energy in) versus the amount expended (energy out). -when a person is maintaining weight, energy in equals energy out. -when the balance shifts, weight changes. -for each 3500 kcalo- ries eaten in excess, a pound of body fat is stored; similarly, a pound of fat is lost for c h a p t e r 8 chapter outline energy balance energy in: the kcalories foods provide food composition food intake energy out: the kcalories the body expends components of energy expenditure estimating energy requirements body weight, body composition, and health defining healthy body weight body fat and its distribution health risks associated with body weight and body fat highlight 8 eating disorders energy in out when energy in balances with energy out, a person s body weight is stable. -249 250 chapter 8 1 lb body fat = 3500 kcal body fat, or adipose tissue, is composed of a mixture of mostly fat, some protein, and water. -a pound of body fat (454 g) is approxi- mately 87% fat, or (454 (cid:2) 0.87) 395 g, and 395g (cid:2) 9 kcal/g = 3555 kcal. -each 3500 kcalories expended beyond those consumed. -the fat stores of even a healthy-weight adult represent an ample reserve of energy 50,000 to 200,000 kcalories. -dietary guidelines for americans 2005 to maintain body weight in a healthy range, balance kcalories from foods and beverages with kcalories expended. -figure 8-1 bomb calorimeter when food is burned, energy is released in the form of heat. -heat energy is mea- sured in kcalories. -thermometer measures temperature changes insulated container keeps heat from escaping motorized stirrer heating element reaction chamber (bomb) food is burned water in which temperature increase from burning food is measured food energy values can be determined by: direct calorimetry, which measures the amount of heat released indirect calorimetry, which measures the amount of oxygen consumed the number of kcalories that the body derives from a food, in contrast to the number of kcalories determined by calorimetry, is the physiological fuel value. -bomb calorimeter (kal-oh-rim-eh-ter): an instrument that measures the heat energy released when foods are burned, thus provid- ing an estimate of the potential energy of the foods. -calor = heat metron = measure quick changes in body weight are not simple changes in fat stores. -weight gained or lost rapidly includes some fat, large amounts of fluid, and some lean tis- sues such as muscle proteins and bone minerals. -(because water constitutes about 60 percent of an adult s body weight, retention or loss of water can greatly influence body weight.) -even over the long term, the composition of weight gained or lost is normally about 75 percent fat and 25 percent lean. -during starvation, losses of fat and lean are about equal. -(recall from chapter 7 that without adequate carbohy- drate, protein-rich lean tissues break down to provide glucose.) -invariably, though, fat gains and losses are gradual. -the next two sections examine the two sides of the energy-balance equation: energy in and energy out. -in summary when the energy consumed equals the energy expended, a person is in energy balance and body weight is stable. -if more energy is taken in than is ex- pended, a person gains weight. -if more energy is expended than is taken in, a person loses weight. -energy in: the kcalories foods provide foods and beverages provide the energy in part of the energy-balance equation. -how much energy a person receives depends on the composition of the foods and beverages and on the amount the person eats and drinks. -food composition to find out how many kcalories a food provides, a scientist can burn the food in a bomb calorimeter (see figure 8-1). -when the food burns, energy is released in the form of heat. -the amount of heat given off provides a direct measure of the food s en- ergy value (remember that kcalories are units of heat energy). -in addition to releas- ing heat, these reactions generate carbon dioxide and water just as the body s cells do when they metabolize the energy-yielding nutrients. -when the food burns and the chemical bonds break, the carbons (c) and hydrogens (h) combine with oxygens (o) to form carbon dioxide (co2) and water (h2o). -the amount of oxygen con- sumed gives an indirect measure of the amount of energy released. -a bomb calorimeter measures the available energy in foods but overstates the amount of energy that the human body derives from foods. -the body is less effi- cient than a calorimeter and cannot metabolize all of the energy-yielding nutrients in a food completely. -researchers can correct for this discrepancy mathematically to create useful tables of the energy values of foods (such as appendix h). -these energy balance and body composition 251 values provide reasonable estimates, but they do not reflect the precise amount of energy a person will derive from the foods consumed. -the energy values of foods can also be computed from the amounts of carbohy- drate, fat, and protein (and alcohol, if present) in the foods. -* for example, a food containing 12 grams of carbohydrate, 5 grams of fat, and 8 grams of protein will provide 48 carbohydrate kcalories, 45 fat kcalories, and 32 protein kcalories, for a total of 125 kcalories. -(to review how to calculate the energy available from foods, turn to p. -9.) -food intake to achieve energy balance, the body must meet its needs without taking in too much or too little energy. -somehow the body decides how much and how often to eat when to start eating and when to stop. -as you will see, many signals initiate or delay eating. -appetite refers to the sensations of hunger, satiation, and satiety that prompt a person to eat or not eat.2 hunger people eat for a variety of reasons, most obviously (although not necessar- ily most commonly) because they are hungry. -most people recognize hunger as an irritating feeling that prompts thoughts of food and motivates them to start eating. -in the body, hunger is the physiological response to a need for food triggered by chemical messengers originating and acting in the brain, primarily in the hypo- thalamus.3 hunger can be influenced by the presence or absence of nutrients in the bloodstream, the size and composition of the preceding meal, customary eating patterns, climate (heat reduces food intake; cold increases it), exercise, hormones, and physical and mental illnesses. -hunger determines what to eat, when to eat, and how much to eat. -the stomach is ideally designed to handle periodic batches of food, and people typically eat meals at roughly four-hour intervals. -four hours after a meal, most, if not all, of the food has left the stomach. -most people do not feel like eating again until the stomach is either empty or almost so. -even then, a person may not feel hungry for quite a while. -satiation during the course of a meal, as food enters the gi tract and hunger di- minishes, satiation develops. -as receptors in the stomach stretch and hormones such as cholecystokinin increase, the person begins to feel full.4 the response: satia- tion occurs and the person stops eating. -satiety after a meal, the feeling of satiety continues to suppress hunger and al- lows a person to not eat again for a while. -whereas satiation tells us to stop eating, satiety reminds us to not start eating again. -figure 8-2 (p. 252) summarizes the re- lationships among hunger, satiation, and satiety. -of course, people can override these signals, especially when presented with stressful situations or favorite foods. -overriding hunger and satiety not surprisingly, eating can be triggered by signals other than hunger, even when the body does not need food. -some people ex- perience food cravings when they are bored or anxious. -in fact, they may eat in re- sponse to any kind of stress, negative or positive. -( what do i do when i m grieving? -eat. -what do i do when i m celebrating? -eat! ) -many people respond to external cues such as the time of day ( it s time to eat ) or the availability, sight, and taste of food ( i d love a piece of chocolate even though i m stuffed ). -environmen- tal influences such as large portion sizes, favorite foods, or an abundance or variety of foods stimulate eating and increase energy intake.5 these cognitive influences can easily lead to weight gain. -eating can also be suppressed by signals other than satiety, even when a person is hungry. -people with the eating disorder anorexia nervosa, for example, use * some of the food energy values in the table of food composition in appendix h were derived by bomb calorimetry, and many were calculated from their energy-yielding nutrient contents. -reminder: 1 g carbohydrate = 4 kcal 1 g fat = 9 kcal 1 g protein = 4 kcal 1 g alcohol = 7 kcal as chapter 1 mentioned, many scientists measure food energy in kilojoules instead. -conversion factors for these and other measures are in the aids to calculation sec- tion on the last two pages of the book. -eating in response to arousal is called stress eating. -cognitive influences include perceptions, memories, intellect, and social interactions. -appetite: the integrated response to the sight, smell, thought, or taste of food that initiates or delays eating. -hunger: the painful sensation caused by a lack of food that initiates food-seeking behavior. -hypothalamus (high-po-thal-ah-mus): a brain center that controls activities such as maintenance of water balance, regulation of body temperature, and control of appetite. -satiation (say-she-ay-shun): the feeling of satisfaction and fullness that occurs during a meal and halts eating. -satiation determines how much food is consumed during a meal. -satiety: the feeling of fullness and satisfaction that occurs after a meal and inhibits eating until the next meal is called. -satiety determines how much time passes between meals. -252 chapter 8 figure 8-2 hunger, satiation, and satiety 1 physiological influences (cid:129) empty stomach (cid:129) gastric contractions (cid:129) absence of nutrients in small intestine (cid:129) gi hormones (cid:129) endorphins (the brain s pleasure chemicals) are triggered by the smell, sight, or taste of foods, enhancing the desire for them 5 postabsorptive influences (after nutrients enter the blood) (cid:129) nutrients in the blood signal the brain (via nerves and hormones) about their availability, use, and storage (cid:129) as nutrients dwindle, satiety diminishes. -(cid:129) hunger develops 1 hunger banana stock, ltd./jupiter images 2 seek food and start meal 2 sensory influences (cid:129) thought, sight, smell, sound, taste of food 5 satiety: several hours later 3 keep eating 4 satiation: end meal 4 postingestive influences (after food enters the digestive tract) (cid:129) food in stomach triggers stretch receptors (cid:129) nutrients in small intestine elicit hormones (for example, fat elicits cholecystokinin, which slows gastric emptying) 3 cognitive influences (cid:129) presence of others, social stimulation (cid:129) perception of hunger, awareness of fullness (cid:129) favorite foods, foods with special meanings (cid:129) time of day (cid:129) abundance of available food s e g a m i r e t i p u j / s a t a e r c s e g a m i r e t i p u j / s a t a e r c i s b r o c / s s e r p x o f e n e b tremendous discipline to ignore the pangs of hunger. -some people simply cannot eat during times of stress, negative or positive. -( i m too sad to eat. -i m too ex- cited to eat! ) -why some people overeat in response to stress and others cannot eat at all remains a bit of a mystery, although researchers are beginning to understand the connections between stress hormones, brain activity, and comfort foods. -6 fac- tors that appear to be involved include how the person perceives the stress and whether usual eating behaviors are restrained. -(highlight 8 features anorexia ner- vosa and other eating disorders.) -sustaining satiation and satiety the extent to which foods produce satiation and sustain satiety depends in part on the nutrient composition of a meal.7 of the three energy-yielding nutrients, protein is considered the most satiating. -foods low in en- ergy density are also more satiating.8 high-fiber foods effectively provide satiation by filling the stomach and delaying the absorption of nutrients. -for this reason, eating a large salad as a first course helps a person eat less during the meal.9 in contrast, fat has a weak effect on satiation; consequently, eating high-fat foods may lead to pas- sive overconsumption. -high-fat foods are flavorful, which stimulates the appetite and entices people to eat more. -high-fat foods are also energy dense; consequently, they deliver more kcalories per bite. -(chapter 1 introduced the concept of energy den- sity, and chapter 9 describes how considering a food s energy density can help with weight management.) -although fat provides little satiation during a meal, it pro- duces strong satiety signals once it enters the intestine. -fat in the intestine triggers the release of cholecystokinin a hormone that signals satiety and inhibits food intake.10 eating high-fat foods while trying to limit energy intake requires small portion sizes, which can leave a person feeling unsatisfied. -portion size correlates directly with a food s satiety. -instead of eating small portions of high-fat foods and feeling satiating: having the power to suppress hunger and inhibit eating. -energy balance and body composition 253 deprived, a person can feel satisfied by eating large portions of high-protein and high-fiber foods. -figure 8-3 illustrates how fat influences portion size. -message central the hypothalamus as you can see, eating is a complex be- havior controlled by a variety of psychological, social, metabolic, and physiological factors. -the hypothalamus appears to be the control center, integrating messages about energy intake, expenditure, and storage from other parts of the brain and from the mouth, gi tract, and liver. -some of these messages influence satiation, which helps control the size of a meal; others influence satiety, which helps deter- mine the frequency of meals. -dozens of chemicals in the brain participate in appetite control and energy bal- ance. -by understanding the action of these brain chemicals, researchers may one day be able to control appetite. -the greatest challenge now is to sort out the many actions of these brain chemicals. -for example, one of these chemicals, neuropeptide y, causes carbohydrate cravings, initiates eating, decreases energy expenditure, and in- creases fat storage all factors favoring a positive energy balance and weight gain. -i s b r o c / n e k n a r f n e w o in summary a mixture of signals governs a person s eating behaviors. -hunger and appetite initiate eating, whereas satiation and satiety stop and delay eating, respec- tively. -each responds to messages from the nervous and hormonal systems. -superimposed on these signals are complex factors involving emotions, habits, and other aspects of human behavior. -energy out: the kcalories the body expends chapter 7 explained that heat is released whenever the body breaks down carbohy- drate, fat, or protein for energy and again when that energy is used to do work. -the generation of heat, known as thermogenesis, can be measured to determine the amount of energy expended. -the total energy a body expends reflects three main categories of thermogenesis: energy expended for basal metabolism energy expended for physical activity figure 8-3 how fat influences portion sizes 837 kcal 71 g fat 100 kcal 9 g fat regardless of hunger, people typically overeat when offered the abundance and variety of an all you can eat buffet. -energy expenditure, like food energy, can be determined by: direct calorimetry, which measures the amount of heat released indirect calorimetry, which measures the amount of oxygen consumed and carbon dioxide expelled neuropeptide y: a chemical produced in the brain that stimulates appetite, diminishes energy expenditure, and increases fat storage. -thermogenesis: the generation of heat; used in physiology and nutrition studies as an index of how much energy the body is expending. ) -h t o b ( . -c n i s o i d u t s a r a l o p 55 kcal 3 g fat 100 kcal 5 g fat for the same size portion, peanuts deliver more than 15 times the kcalories and 20 times the fat of popcorn. -for the same number of kcalories, a person can have a few high-fat peanuts or almost 2 cups of high-fiber popcorn. -(this comparison used oil-based popcorn; using air-popped popcorn would double the amount of popcorn in this example.) -254 chapter 8 figure 8-4 components of energy expenditure the amount of energy spent in a day differs for each individual, but in gen- eral, basal metabolism is the largest component of energy expenditure and the thermic effect of food is the small- est. -the amount spent in voluntary physical activities has the greatest vari- ability, depending on a person s activity patterns. -for a sedentary person, physi- cal activities may account for less than half as much energy as basal metabo- lism, whereas an extremely active per- son may expend as much on activity as for basal metabolism. -30-50% physical activities 10% thermic effect of food 50-65% basal metabolism quick and easy estimates for basal energy needs: men: slightly (cid:3)1 kcal/min (1.1 to 1.3 kcal/min) or 24 kcal/kg/day women: slightly (cid:4)1 kcal/min (0.8 to 1.0 kcal/min) or 23 kcal/kg/day for perspective, a burning candle or a 75- watt light bulb releases about 1 kcal/min. -basal metabolism: the energy needed to maintain life when a body is at complete digestive, physical, and emotional rest. -basal metabolic rate (bmr): the rate of energy use for metabolism under specified conditions: after a 12-hour fast and restful sleep, without any physical activity or emotional excitement, and in a comfortable setting. -it is usually expressed as kcalories per kilogram body weight per hour. -resting metabolic rate (rmr): similar to the basal metabolic rate (bmr), a measure of the energy use of a person at rest in a comfortable setting, but with less stringent criteria for recent food intake and physical activity. -consequently, the rmr is slightly higher than the bmr. -lean body mass: the body minus its fat content. -energy expended for food consumption a fourth category is sometimes involved: energy expended for adaptation components of energy expenditure people expend energy when they are physically active, of course, but they also ex- pend energy when they are resting quietly. -in fact, quiet metabolic activities account for the lion s share of most people s energy expenditures, as figure 8-4 shows. -basal metabolism about two-thirds of the energy the average person expends in a day supports the body s basal metabolism. -metabolic activities maintain the body temperature, keep the lungs inhaling and exhaling air, the bone marrow mak- ing new red blood cells, the heart beating 100,000 times a day, and the kidneys fil- tering wastes in short, they support all the basic processes of life. -the basal metabolic rate (bmr) is the rate at which the body expends en- ergy for these maintenance activities. -the rate may vary dramatically from per- son to person and may vary for the same individual with a change in circumstance or physical condition. -the rate is slowest when a person is sleeping undisturbed, but it is usually measured in a room with a comfortable temperature when the per- son is awake, but lying still, after a restful sleep and an overnight (12 to 14 hour) fast. -a similar measure of energy output called the resting metabolic rate (rmr) is slightly higher than the bmr because its criteria for recent food intake and physical activity are not as strict. -in general, the more a person weighs, the more total energy is expended on basal metabolism, but the amount of energy per pound of body weight may be lower. -for example, an adult s bmr might be 1500 kcalories per day and an in- fant s only 500, but compared to body weight, the infant s bmr is more than twice as fast. -similarly, a normal-weight adult may have a metabolic rate one and a half times that of an obese adult when compared to body weight because lean tissue is metabolically more active than body fat. -table 8-1 summarizes the factors that raise and lower the bmr. -for the most part, the bmr is highest in people who are growing (children, adolescents, and pregnant women) and in those with considerable lean body mass (physically fit people and males). -one way to increase the bmr then is to participate in en- durance and strength-training activities regularly to maximize lean body mass. -the bmr is also high in people with fever or under stress and in people with highly active thyroid glands. -the bmr slows down with a loss of lean body mass and dur- ing fasting and malnutrition. -physical activity the second component of a person s energy output is physical activ- ity: voluntary movement of the skeletal muscles and support systems. -physical activity is the most variable and the most changeable component of energy expenditure. -consequently, its influence on both weight gain and weight loss can be significant. -during physical activity, the muscles need extra energy to move, and the heart and lungs need extra energy to deliver nutrients and oxygen and dispose of wastes. -the amount of energy needed for any activity, whether playing tennis or studying for an exam, depends on three factors: muscle mass, body weight, and activity. -the larger the muscle mass and the heavier the weight of the body part being moved, the more energy is expended. -table 8-2 gives average energy expen- ditures for various activities. -the activity s duration, frequency, and intensity also influence energy expenditure: the longer, the more frequent, and the more intense the activity, the more kcalories expended. -(chapter 14 describes how an activity s duration, frequency, and intensity also influence the body s use of the energy- yielding nutrients.) -thermic effect of food when a person eats, the gi tract muscles speed up their rhythmic contractions, the cells that manufacture and secrete digestive juices energy balance and body composition 255 table 8-1 factors that affect the bmr factor age height growth effect on bmr lean body mass diminishes with age, slowing the bmr.a in tall, thin people, the bmr is higher.b in children and pregnant women, the bmr is higher. -body composition (gender) the more lean tissue, the higher the bmr (which is why males usually have a higher bmr than females). -the more fat tissue, the lower the bmr. -fever stresses environmental temperature fever raises the bmr.c stresses (including many diseases and certain drugs) raise the bmr. -both heat and cold raise the bmr. -fasting/starvation fasting/starvation lowers the bmr.d malnutrition malnutrition lowers the bmr. -hormones (gender) the thyroid hormone thyroxin, for example, can speed up or slow down the bmr.e premenstrual hormones slightly raise the bmr. -smoking caffeine sleep nicotine increases energy expenditure. -caffeine increases energy expenditure. -bmr is lowest when sleeping. -athe bmr begins to decrease in early adulthood (after growth and development cease) at a rate of about 2 percent/decade. -a reduction in voluntary activity as well brings the total decline in energy expenditure to 5 percent/decade. -bif two people weigh the same, the taller, thinner person will have the faster metabolic rate, reflecting the greater skin surface, through which heat is lost by radiation, in proportion to the body s volume (see the margin drawing on p. 256). -cfever raises the bmr by 7 percent for each degree fahrenheit. -dprolonged starvation reduces the total amount of metabolically active lean tissue in the body, although the decline occurs sooner and to a greater extent than body losses alone can explain. -more likely, the neural and hormonal changes that accom- pany fasting are responsible for changes in the bmr. -ethe thyroid gland releases hormones that travel to the cells and influence cellular metabolism. -thyroid hormone activity can speed up or slow down the rate of metabolism by as much as 50 percent. -table 8-2 energy expended on various activities the values listed in this table reflect both the energy expended in physical activity and the amount used for bmr. -to calculate kcalories spent per minute of activity for your own body weight, multiply kcal/lb/min (or kcal/kg/min) by your exact weight and then multiply that number by the number of minutes spent in the activity. -for example, if you weigh 142 pounds, and you want to know how many kcalories you spent doing 30 minutes of vigorous aerobic dance: 0.062 (cid:2) 142 (cid:5) 8.8 kcalories per minute; 8.8 (cid:2) 30 minutes (cid:5) 264 total kcalories spent. -activity aerobic dance (vigorous) basketball (vigorous, full court) bicycling 13 mph 15 mph 17 mph 19 mph 21 mph 23 mph 25 mph canoeing, flat water, moderate pace cross-country skiing 8 mph gardening golf (carrying clubs) kcal/lb min kcal/kg min .062 .136 .097 .213 .045 .049 .057 .076 .090 .109 .139 .099 .108 .125 .167 .198 .240 .306 .045 .099 .104 .045 .045 .229 .099 .099 activity handball horseback riding (trot) rowing (vigorous) running 5 mph 6 mph 7.5 mph 9 mph 10 mph 11 mph soccer (vigorous) studying swimming 20 yd/min 45 yd/min 50 yd/min kcal/lb min kcal/kg min .078 .052 .097 .061 .074 .094 .103 .114 .131 .097 .011 .032 .058 .070 .172 .114 .213 .134 .163 .207 .227 .251 .288 .213 .024 .070 .128 .154 activity table tennis (skilled) tennis (beginner) vacuuming and other household tasks walking (brisk pace) 3.5 mph 4.5 mph weight lifting light-to-moderate effort vigorous effort wheelchair basketball wheeling self in wheelchair kcal/lb min kcal/kg min .045 .032 .099 .070 .030 .066 .035 .048 .024 .048 .084 .030 .077 .106 .053 .106 .185 .066 256 chapter 8 thermic effect of foods: carbohydrate: 5 10% fat: 0 5% protein: 20 30% alcohol: 15 20% the percentages are calculated by dividing the energy expended during digestion and absorption (above basal) by the energy con- tent of the food. -note that table 8-1 (p. 255) lists these fac- tors among those that influence bmr and consequently energy expenditure. -each of these structures is made of 8 blocks. -they weigh the same, but they are arranged differently. -the short, wide structure has 24 sides and the tall, thin one has 34. because the tall, thin structure has a greater surface area, it will lose more heat (expend more energy) than the short, wide one. -similarly, two people of different heights might weigh the same, but the taller, thin one will have a higher bmr (expending more energy) because of the greater skin surface. -thermic effect of food (tef): an estimation of the energy required to process food (digest, absorb, transport, metabolize, and store ingested nutrients); also called the specific dynamic effect (sde) of food or the specific dynamic activity (sda) of food. -the sum of the tef and any increase in the metabolic rate due to overeating is known as diet-induced thermogenesis (dit). -adaptive thermogenesis: adjustments in energy expenditure related to changes in environment such as extreme cold and to physiological events such as overfeeding, trauma, and changes in hormone status. -begin their tasks, and some nutrients are absorbed by active transport. -this accel- eration of activity requires energy and produces heat; it is known as the thermic effect of food (tef). -the thermic effect of food is proportional to the food energy taken in and is usu- ally estimated at 10 percent of energy intake. -thus a person who ingests 2000 kcalories probably expends about 200 kcalories on the thermic effect of food. -the proportions vary for different foods, however, and are also influenced by factors such as meal size and frequency. -in general, the thermic effect of food is greater for high-protein foods than for high-fat foods and for a meal eaten all at once rather than spread out over a couple of hours. -some research suggests that the thermic effect of food is reduced in obese people and may contribute to their effi- cient storage of fat.11 for most purposes, however, the thermic effect of food can be ignored when estimating energy expenditure because its contribution to total en- ergy output is smaller than the probable errors involved in estimating overall en- ergy intake and output. -adaptive thermogenesis some additional energy is spent when a person must adapt to dramatically changed circumstances (adaptive thermogenesis). -when the body has to adapt to physical conditioning, extreme cold, overfeeding, starva- tion, trauma, or other types of stress, it has extra work to do, building the tissues and producing the enzymes and hormones necessary to cope with the demand. -in some circumstances, this energy makes a considerable difference in the total energy ex- pended. -because this component of energy expenditure is so variable and specific to individuals, it is not included when calculating energy requirements. -estimating energy requirements in estimating energy requirements, the dri committee developed equations that consider how the following factors influence energy expenditure: gender. -in general, women have a lower bmr than men, in large part be- cause men typically have more lean body mass. -two sets of energy equa- tions one for men and one for women were developed to accommodate the influence of gender on energy expenditure. -growth. -the bmr is high in people who are growing. -for this reason, preg- nant women, infants, children, and adolescents have their own sets of en- ergy equations (see appendix f). -age. -the bmr declines during adulthood as lean body mass diminishes. -this change in body composition occurs, in part, because some hormones that influence appetite, body weight, and metabolism become more, or less, ac- tive with age.12 physical activities tend to decline as well, bringing the aver- age reduction in energy expenditure to about 5 percent per decade. -the decline in the bmr that occurs when a person becomes less active reflects the loss of lean body mass and may be minimized with ongoing physical activ- ity. -because age influences energy expenditure, it is also factored into the en- ergy equations. -physical activity. -using individual values for various physical activities (as in table 8-2) is time-consuming and impractical for estimating the energy needs of a population. -instead, various activities are clustered according to the typical intensity of a day s efforts. -energy equations include a physical activity factor for various levels of intensity for each gender. -body composition and body size. -the bmr is high in people who are tall and so have a large surface area. -similarly, the more a person weighs, the more energy is expended on basal metabolism. -for these reasons, the energy equations include a factor for both height and weight. -as just explained, energy needs vary between individuals depending on such factors as gender, growth, age, physical activity, and body size and composition. -energy balance and body composition 257 even when two people are similarly matched, however, their energy needs still dif- fer because of genetic differences. -perhaps one day genetic research will reveal how to estimate requirements for each individual. -for now, the accompanying how to provides instructions on calculating your estimated energy requirements using the dri equations and physical activity factors. -in summary a person in energy balance takes in energy from food and expends much of it on basal metabolic activities, some of it on physical activities, and a little on the thermic effect of food. -because energy requirements vary from person to person, such factors as gender, age, weight, and height as well as the intensity and duration of physical activity must be considered when estimating energy requirements. -s e g a m i y t t e g / e n o t s / z e r r o t b o b how to estimate energy requirements to determine your estimated energy re- quirements (eer), use the appropriate equation, inserting your age in years, weight (wt) in kilograms, height (ht) in meters, and physical activity (pa) factor from the accompanying table. -(to convert pounds to kilograms, divide by 2.2; to convert inches to meters, divide by 39.37.) -for men 19 years and older: eer (cid:5) [662 (cid:6) (9.53 (cid:2) age)] (cid:7) pa (cid:2) [(15.91 (cid:2) wt) (cid:7) (539.6 (cid:2) ht)] for women 19 years and older: eer (cid:5) [354 (cid:6) (6.91 (cid:2) age)] (cid:7) pa (cid:2) [(9.36 (cid:2) wt) (cid:7) (726 (cid:2) ht)] for example, consider an active 30- year-old male who is 5 feet 11 inches tall and weighs 178 pounds. -first, he con- verts his weight from pounds to kilograms and his height from inches to meters, if necessary: 178 lb (cid:8) 2.2 (cid:5) 80.9 kg 71 in (cid:8) 39.37 (cid:5) 1.8 m next, he considers his level of daily physi- cal activity and selects the appropriate pa factor from the accompanying table. -(in this example, 1.25 for an active male.) -then, he inserts his age, pa factor, weight, and height into the appropriate equation: eer (cid:5) [662 (cid:6) (9.53 (cid:2) 30)] (cid:7) 1.25 (cid:2) [(15.91 (cid:2) 80.9) (cid:7) (539.6 (cid:2) 1.8)] (a reminder: do calculations within the parentheses first.) -he calculates: eer (cid:5) [662 (cid:6) 286] (cid:7) 1.25 (cid:2) [1287 (cid:7) 971] (another reminder: do calculations within the brackets next.) -eer = 376 (cid:7) 1.25 (cid:2) 2258 (one more reminder: do multiplication before addition.) -eer (cid:5) 376 (cid:7) 2823 eer (cid:5) 3199 the estimated energy requirement for an active 30-year-old male who is 5 feet 11 inches tall and weighs 178 pounds is about 3200 kcalories/day. -his actual requirement probably falls within a range of 200 kcalories above and below this estimate. -note: appendix f provides eer equations for infants, children, adolescents, and pregnant women. -physical activity (pa) factors for eer equations men women physical activity sedentary low active active very active 1.0 1.11 1.25 1.48 1.0 1.12 1.27 1.45 typical daily living activities plus 30 60 min moderate activity plus (cid:9) 60 min moderate activity plus (cid:9) 60 min moderate activity and 60 min vigorous or 120 min moderate activity note: moderate activity is equivalent to walking at 3 to 41/2 mph. -it feels like work and it may make you tired, but studying requires only one or two kcalories per minute. -appendix f presents dri tables that pro- vide a shortcut to estimating total energy expenditure and instructions to help you determine the appropriate physical activity factor to use in the equation. -for most people, the actual energy require- ment falls within these ranges: for men, eer 200 kcal for women, eer 160 kcal for almost all people, the actual energy requirement falls within these ranges: for men, eer 400 kcal for women, eer 320 kcal to practice estimating energy requirements, log on to www.thomsonedu.com/thomsonnow, go to chapter 8, then go to how to. -258 chapter 8 body weight, body composition, and health a person 5 feet 10 inches tall who weighs 150 pounds may carry only about 30 of those pounds as fat. -the rest is mostly water and lean tissues muscles, organs such as the heart and liver, and the bones of the skeleton. -direct measures of body com- position are impossible in living human beings; instead, researchers assess body composition indirectly based on the following assumption: image not available due to copyright restrictions body weight = fat + lean tissue (including water) in metric terms, a person 1.78 meters tall who weighs 68 kilograms may carry only about 14 of those kilograms as fat. -weight gains and losses tell us nothing about how the body s composition may have changed, yet weight is the measure most people use to judge their fatness. -for many people, overweight means overfat, but this is not always the case. -ath- letes with dense bones and well-developed muscles may be overweight by some standards but have little body fat. -conversely, inactive people may seem to have acceptable weights, when, in fact, they may have too much body fat. -defining healthy body weight how much should a person weigh? -how can a person know if her weight is appro- priate for her height? -how can a person know if his weight is jeopardizing his health? -such questions seem so simple, yet the answers can be complex and quite different depending on whom you ask. -the criterion of fashion in asking what is ideal, people often mistakenly turn to fashion for the answer. -no doubt our society sets unrealistic ideals for body weight, especially for women. -miss america, our nation s icon of beauty, has never been overweight, and until recently, she has grown progressively thinner over the years (see figure 8-5). -magazines, movies, and television all convey the message that to be thin is to be beautiful and happy. -as a result, the media have a great influence on the weight concerns and dieting patterns of people of all ages, but most tragically on young, impressionable children and adolescents.13 one-half of preteen girls and one-third of preteen boys are dissatisfied with their body weight and shape.14 figure 8-5 the declining weight of miss america bmi 21 19 17 s i b r o c / d o o w r e d n u d n a d o o w r e d n u 1930 1950 1970 1990 2010 s o t o h p d l r o w e d i w / p a miss america 1944 miss america 1986 as explained on p. 259, the body mass index (bmi) describes relative weight for height. -over the years, the bmi of miss america has declined steadily. -since the mid- 1960s, most have fallen below 18.5, the cutoff point indicating underweight with its associated health problems. -source: s. rubenstein and b. caballero, is miss america an undernourished role model? -journal of the american medical associa- tion 283 (2000): 1569. body composition: the proportions of muscle, bone, fat, and other tissue that make up a person s total body weight. -table 8-3 tips for accepting a healthy body weight value yourself and others for human attributes other than body weight. -realize that prejudging people by weight is as harmful as prejudging them by race, religion, or gender. -use positive, nonjudgmental descriptions of your body. -accept positive comments from others. -focus on your whole self including your intelligence, social grace, and professional and scholastic achievements. -accept that no magic diet exists. -stop dieting to lose weight. -adopt a lifestyle of healthy eating and physi- cal activity permanently. -energy balance and body composition 259 follow the usda food guide. -never restrict food intake below the mini- mum levels that meet nutrient needs. -become physically active, not because it will help you get thin but because it will make you feel good and enhance your health. -seek support from loved ones. -tell them of your plan for a healthy life in the body you have been given. -seek professional counseling, not from a weight-loss counselor, but from someone who can help you make gains in self-esteem without weight as a factor. -importantly, perceived body image has little to do with actual body weight or size. -people of all shapes, sizes, and ages including extremely thin fashion mod- els with anorexia nervosa and fitness instructors with ideal body composition have learned to be unhappy with their overweight bodies. -such dissatisfaction can lead to damaging behaviors, such as starvation diets, diet pill abuse, and health care avoidance.15 the first step toward making healthy changes may be self-acceptance. -keep in mind that fashion is fickle; the body shapes valued by our society change with time. -furthermore, body shapes valued by our society differ from those of other societies. -the standards defining ideal are subjective and fre- quently have little in common with health. -table 8-3 offers some tips for adopting health as an ideal, rather than society s misconceived image of beauty. -the criterion of health even if our society were to accept fat as beautiful, obesity would still be a major risk factor for several life-threatening diseases. -for this reason, the most important criterion for determining how much a person should weigh and how much body fat a person needs is not appearance but good health and longevity. -ideally, a person has enough fat to meet basic needs but not so much as to incur health risks. -this range of healthy body weights has been identified using a common measure of weight and height the body mass index. -body mass index the body mass index (bmi) describes relative weight for height: s e g a m i y t t e g / e n o t s / k e e p i k s m a d a i r o l bmi = weight (kg) or height (m)2 weight (lb) (cid:2) 703 height (in)2 weight classifications based on bmi are presented in figure 8-6 (p. 260). -notice that healthy weight falls between a bmi of 18.5 and 24.9, with underweight below 18.5, overweight above 25, and obese above 30. well over half of adults in the united states have a bmi greater than 25, as figure 8-7 (p. 260) shows.16 a bmi of 25 for adults represents a healthy target for overweight people to achieve or for others not to exceed. -obesity-related diseases and increased mortality become evident beyond a bmi of 25. the lower end of the healthy range may be a reasonable target for severely underweight people. -bmi values slightly below the healthy range may be compatible with good health if food intake is adequate, but signs of illness, reduced work capacity, and poor reproductive function become ap- parent when bmi is below 17. the inside back cover presents weights and visual im- ages associated with various bmi values. -the how to on p. 261 describes how to determine an appropriate body weight based on bmi. -keep in mind that bmi reflects height and weight measures and not body com- position. -consequently, muscular athletes may be classified as overweight by bmi standards and not be overfat.17 at the peak of his bodybuilding career, arnold schwarzenegger won the mr. olympia competition with a bmi of 31; the runner on p. 258 also has a bmi greater than 30. yet neither would be considered obese. -strik- ing differences in body composition are also apparent among people of various ethnic and racial groups, making standard bmi guidelines inappropriate for some a healthy body contains enough lean tissue to support health and the right amount of fat to meet body needs. -to convert pounds to kilograms: lb (cid:2) 2.2 lb/kg = kg to convert inches to meters: in (cid:2) 39.37 in/m = m body mass index (bmi): an index of a person s weight in relation to height; determined by dividing the weight (in kilograms) by the square of the height (in meters). -underweight: body weight below some standard of acceptable weight that is usually defined in relation to height (such as bmi); bmi below 18.5. overweight: body weight above some standard of acceptable weight that is usually defined in relation to height (such as bmi); bmi 25 to 29.9. obese: overweight with adverse health effects; bmi 30 or higher. -260 chapter 8 figure 8-6 bmi values used to assess weight figure 8-7 distribution of body weights in u.s. adults healthy weight (bmi 18.5 24.9) overweight (bmi 25 29.9) obesity (bmi 30 39.9) underweight (bmi <18.5) extreme obesity (bmi (cid:9)40) ) s e o h s t u o h t i w ( t h g e h i 6'6" 6'5" 6'4" 6'3" 6'2" 6'1" 6'0" 5'11" 5'10" 5'9" 5'8" 5'7" 5'6" 5'5" 5'4" 5'3" 5'2" 5'1" 5'0" 4'11" 4'10" 50 18.5 25 30 underweight healthy overweight obese key: bmi <18.5 = underweight bmi 18.5 to 24.9 = healthy bmi 25.0 to 29.9 = overweight bmi (cid:9) 30 = obese 75 100 125 150 175 200 225 250 275 pounds (without clothes) note: chapter 16 presents bmi values for children and adolescents age 2 to 20. source: u.s. department of agriculture and u.s. department of health and human services, nutrition and your health: dietary guidelines for americans (washington, d.c.: 2000), p. 7. populations.18 for example, blacks tend to have a greater bone density and protein content than whites; consequently, using bmi as the standard may overestimate the prevalence of obesity among blacks. -in summary current standards for body weight are based on a person s weight in relation to height, called the body mass index (bmi), and reflect disease risks. -to its dis- advantage, bmi does not reflect body fat, and it may misclassify very muscu- lar people as overweight. -body fat and its distribution although weight measures are inexpensive, easy to take, and highly accurate, they fail to reveal two valuable pieces of information in assessing disease risk: how much of the weight is fat and where the fat is located. -the ideal amount of body fat depends partly on the person. -a normal-weight man may have from 13 to 21 percent body fat; a woman, because of her greater quantity of essential fat, 23 to 31 percent. -in general, health problems typically develop when body fat exceeds 22 percent in young men, 25 percent in men over age 40, 32 percent in young women, and 35 percent in women over age 40. body fat may contribute as much as 70 percent in excessively obese adults. -figure 8-8 compares the body composi- tion of healthy weight men and women. -energy balance and body composition 261 to determine bmi, log on to www.thomsonedu .com/thomsonnow, go to chapter 8, then go to how to. -how to determine body weight based on bmi a person whose bmi reflects an unaccept- able health risk can choose a desired bmi and then calculate an appropriate body weight. -for example, a woman who is 5 feet 5 inches (1.65 meters) tall and weighs 180 pounds (82 kilograms) has a bmi of 30: bmi (cid:5) 82 kg (cid:5) 30 1.65 m2 or bmi (cid:5) 180 lb (cid:2) 703 (cid:5) 30 65 in2 a reasonable target for most overweight people is a bmi 2 units below their cur- rent one. -to determine a desired goal weight based on a bmi of 28, for exam- ple, the woman could divide the desired bmi by the factor appropriate for her height from the table below: desired bmi (cid:8) factor (cid:5) goal weight 28 (cid:8) 0.166 (cid:5) 169 lb to reach a bmi of 28, this woman would need to lose 11 pounds. -such a calcula- tion can help a person to determine realis- tic weight goals using health risk as a guide. -alternatively, a person could search the table on the inside back cover for the weight that corresponds to his or her height and the desired bmi. -height factor height factor height factor 4 7 (1.40 m) 4 8 (1.42 m) 4 9 (1.45 m) 4 10 (1.47 m) 4 11 (1.50 m) 5 0 (1.52 m) 5 1 (1.55 m) 5 2 (1.57 m) 0.232 0.224 0.216 0.209 0.202 0.195 0.189 0.183 5 3 (1.60 m) 5 4 (1.63 m) 5 5 (1.65 m) 5 6 (1.68 m) 5 7 (1.70 m) 5 8 (1.73 m) 5 9 (1.75 m) 5 10 (1.78 m) 0.177 0.172 0.166 0.161 0.157 0.152 0.148 0.143 5 11 (1.80 m) 6 0 (1.83 m) 6 1 (1.85 m) 6 2 (1.88 m) 6 3 (1.90 m) 6 4 (1.93 m) 6 5 (1.96 m) 6 6 (1.98 m) 0.139 0.136 0.132 0.128 0.125 0.122 0.119 0.116 source: r. p. abernathy, body mass index: determination and use, journal of the american dietetic association 91 (1991): 843. some people need less body fat for many athletes, a lower percentage of body fat may be ideal just enough fat to provide fuel, insulate and protect the body, assist in nerve impulse transmissions, and support normal hormone activity, text not available due to copyright restrictions 262 chapter 8 figure 8-9 abdominal fat in healthy weight people, some fat is stored around the organs of the abdomen. -in overweight people, excess abdominal fat increases the risks of diseases. -but not so much as to burden the body with excess bulk. -for some athletes, then, ideal body fat might be 5 to 10 percent for men and 15 to 20 percent for women. -(re- view the photo on p. 258 to appreciate what 8 percent body fat looks like.) -some people need more body fat for an alaska fisherman, a higher percent- age of body fat is probably beneficial because fat provides an insulating blanket to prevent excessive loss of body heat in cold climates. -a woman starting a pregnancy needs sufficient body fat to support conception and fetal growth. -below a certain threshold for body fat, hormone synthesis falters, and individuals may become in- fertile, develop depression, experience abnormal hunger regulation, or become un- able to keep warm. -these thresholds differ for each function and for each individual; much remains to be learned about them. -fat distribution the distribution of fat on the body may be more critical than the to- tal amount of fat alone. -intra-abdominal fat that is stored around the organs of the abdomen is referred to as central obesity or upper-body fat (see figure 8-9). -indepen- dently of bmi or total body fat, central obesity is associated with increased risks of heart disease, stroke, diabetes, hypertension, gallstones, and some types of cancer.19 abdominal fat is most common in men and to a lesser extent in women past menopause. -even when total body fat is similar, men have more abdominal fat than women. -regardless of gender, the risks of cardiovascular disease, diabetes, and mortal- ity are increased for those with excessive abdominal fat. -interestingly, smokers tend to have more abdominal fat than nonsmokers even though they have lower bmi.20 fat around the hips and thighs, sometimes referred to as lower-body fat, is most common in women during their reproductive years and seems relatively harmless. -in fact, overweight people who do not have abdominal fat are less susceptible to intra-abdominal fat: fat stored within the abdominal cavity in association with the internal abdominal organs, as opposed to the fat stored directly under the skin (subcutaneous fat). -central obesity: excess fat around the trunk of the body; also called abdominal fat or upper-body fat. -energy balance and body composition 263 figure 8-10 body shapes compared apple and pear popular articles sometimes call bodies with upper-body fat apples and those with lower-body fat, pears. -researchers sometimes refer to upper-body fat as android (manlike) obesity and to lower- body fat as gynoid (womanlike) obesity. -upper-body fat is more common in men than in women and is closely associated with heart disease, stroke, diabetes, hypertension, and some types of cancer. -lower body fat is more common in women than in men and is not usually associated with chronic diseases. -health problems than overweight people with abdominal fat. -figure 8-10 com- pares the body shapes of people with upper-body fat and lower-body fat. -waist circumference a person s waist circumference is the most practical in- dicator of fat distribution and central obesity. -21 in general, women with a waist cir- cumference of greater than 35 inches (88 centimeters) and men with a waist circumference of greater than 40 inches (102 centimeters) have a high risk of central obesity-related health problems, such as diabetes and cardiovascular disease.22 as waist circumference increases, disease risks increase.23 appendix e includes instruc- tions for measuring waist circumference and assessing abdominal fat. -some researchers use the waist-to-hip ratio when studying disease risks. -the ratio requires another step or two (measuring the hips and comparing that measure to the waist measure), but it does not provide any additional information. -therefore, waist circumference alone is the preferred method for assessing abdominal fat in a clinical setting. -* other measures of body composition health care professionals commonly use bmi and waist circumference measures because they are relatively easy and inexpensive. -together, these two measures prove most valuable in assessing a per- son s health risks and monitoring changes over time.24 researchers needing more precise measures of body composition may choose any of several other techniques to estimate body fat and its distribution (see figure 8-11 on p. 264). -mastering these techniques requires proper instruction and practice to ensure reliability. -in addition to the methods shown in figure 8-11, researchers sometimes estimate body composi- tion using these methods: total body water, radioactive potassium count, near-in- frared spectrophotometry, ultrasound, computed tomography, and magnetic resonance imaging. -each method has advantages and disadvantages with respect to cost, technical difficulty, and precision of estimating body fat (see appendix e for a comparison). -appendix e provides additional details and includes many of the ta- bles and charts routinely used in assessment procedures. -in summary the ideal amount of body fat varies from person to person, but researchers have found that body fat in excess of 22 percent for young men and 32 per- cent for young women (the levels rise slightly with age) poses health risks. -central obesity, in which excess abdominal fat is distributed around the trunk of the body, presents greater health risks than excess fat distributed on the lower body. -health risks associated with body weight and body fat body weight and fat distribution correlate with disease risks and life expectancy.25 they indicate a greater likelihood of developing a chronic disease and shortening life expectancy. -not all overweight and underweight people will get sick and die before their time nor will all normal-weight people live long healthy lives. -correlations are not causes. -for the most part, people with a bmi between 18.5 and 24.9 have rela- tively few health risks; risks increase as bmi falls below or rises above this range, in- dicating that both too little and too much body fat impair health.26 epidemiological data show a j- or u-shaped relationship between body weights and mortality (see figure 8-12, p. 264).27 people who are extremely underweight or extremely obese carry higher risks of early deaths than those whose weights fall within the accept- able range; these mortality risks decline with age.28 * the national heart, lung, and blood institute recommends using the waist circumference instead of the waist-to-hip ratio to assess obesity health risks. -waist circumference: an anthropometric measurement used to assess a person s abdominal fat. -264 chapter 8 figure 8-11 common methods used to assess body fat o h a d i , e s i o b , s s e n l l e w & s s e n t i f t i d e o t o h p / f f l o w - g n u o y d i v a d y h p a r g o t o h p g r e b g n e i r e g skinfold measures estimate body fat by using a caliper to gauge the thickness of a fold of skin on the back of the arm (over the triceps), below the shoulder blade (subscapular), and in other places (including lower-body sites) and then comparing these measurements with standards. -hydrodensitometry measures body density by weighing the person first on land and then again while submerged in water. -the difference between the person s actual weight and underwater weight provides a measure of the body s volume. -a mathematical equation using the two measurements (volume and actual weight) determines body density, from which the percentage of body fat can be estimated. -. -c n i , t n e m e r u s a e m e f i l f o y s e t r u o c o t o h p . -c n i , c i g o l o h f o y s e t r u o c o t o h p bioelectrical impedance measures body fat by using a low-intensity electrical current. -because electrolyte-containing fluids, which readily conduct an electrical current, are found primarily in lean body tissues, the leaner the person, the less resistance to the current. -the measurement of electrical resistance is then used in a mathematical equation to estimate the percentage of body fat. -air displacement plethysmography estimates body composition by having a person sit inside a chamber while computerized sensors determine the amount of air displaced by the person s body. -dual energy x-ray absorptiometry (dexa) uses two low-dose x-rays that differentiate among fat-free soft tissue (lean body mass), fat tissue, and bone tissue, providing a precise measurement of total fat and its distribution in all but extremely obese subjects. -figure 8-12 bmi and mortality this j-shaped curve describes the rela- tionship between body mass index (bmi) and mortality and shows that both underweight and overweight pres- ent risks of a premature death. -s a s e s a e r c n i k s r i s e n i l c e d i m b y t i l a t r o m 15 20 30 25 35 body mass index s e s a e r c n i k s r i s e s i r i m b s a 40 independently of bmi, factors such as smoking habits raise health risks, and physical fitness lowers them.29 a man with a bmi of 22 who smokes two packs of cigarettes a day is jeopardizing his health, whereas a woman with a bmi of 32 who walks briskly for an hour a day is improving her health. -health risks of underweight some underweight people enjoy an active, healthy life, but others are underweight because of malnutrition, smoking habits, substance abuse, or illnesses. -weight and fat measures alone would not reveal these underlying causes, but a complete assessment that includes a diet and medical his- tory, physical examination, and biochemical analysis would. -an underweight person, especially an older adult, may be unable to preserve lean tissue during the fight against a wasting disease such as cancer or a digestive disorder, especially when the disease is accompanied by malnutrition. -without adequate nu- trient and energy reserves, an underweight person will have a particularly tough battle against such medical stresses. -underweight women develop menstrual irregu- larities and become infertile. -exactly how infertility develops is unclear, but contribut- ing factors include body weight as well as restricted energy and fat intake and depleted body fat stores. -those who do conceive may give birth to unhealthy infants. -an underweight woman can improve her chances of having a healthy infant by gaining weight prior to conception, during pregnancy, or both. -underweight and sig- nificant weight loss are also associated with osteoporosis and bone fractures. -for all energy balance and body composition 265 these reasons, underweight people may benefit from enough of a weight gain to pro- vide an energy reserve and protective amounts of all the nutrients that can be stored. -health risks of overweight as for excessive body fat, the health risks are so many that it has been designated a disease obesity. -among the health risks asso- ciated with obesity are diabetes, hypertension, cardiovascular disease, sleep apnea (abnormal ceasing of breathing during sleep), osteoarthritis, some cancers, gall- bladder disease, kidney stones, respiratory problems (including pickwickian syn- drome, a breathing blockage linked with sudden death), and complications in pregnancy and surgery. -each year, these obesity-related illnesses cost our nation bil- lions of dollars in fact, as much as the medical costs of smoking.30 the cost in terms of lives is also great: an estimated 300,000 people die each year from obesity-related diseases. -in fact, obesity is second only to tobacco in causing preventable illnesses and premature deaths. -mortality increases as excess weight increases; people with a bmi greater than 35 are more than twice as likely to die prematurely as others.31 the risks associated with a high bmi appear to be greater for whites than for blacks; in fact, the health risks associated with obesity do not be- come apparent in black women until a bmi of 37.32 equally important, both central obesity and weight gains of more than 20 pounds (9 kilograms) between early and middle adulthood correlate with increased disease risks.33 fluctuations in body weight, as typically occur with yo-yo dieting, may also increase the risks of chronic diseases and premature death. -in contrast, sustained weight loss improves physical well-being, reduces disease risks, and in- creases life expectancy. -cardiovascular disease the relationship between obesity and cardiovascular disease risk is strong, with links to both elevated blood cholesterol and hypertension. -central obesity may raise the risk of heart attack and stroke as much as the three leading risk factors (high ldl cholesterol, hypertension, and smoking) do. -in ad- dition to body fat and its distribution, weight gain also increases the risk of cardio- vascular disease. -weight loss, on the other hand, can effectively lower both blood cholesterol and blood pressure in obese people. -of course, lean and normal-weight people may also have high blood cholesterol and blood pressure, and these factors are just as dangerous in lean people as in obese people. -diabetes most adults with type 2 diabetes are overweight or obese.34 diabetes (type 2) is three times more likely to develop in an obese person than in a nonobese person. -furthermore, the person with type 2 diabetes often has central obesity. -cen- tral-body fat cells appear to be larger and more insulin-resistant than lower-body fat cells.35 the association between insulin resistance and obesity is strong. -both are major risk factors for the development of type 2 diabetes. -diabetes appears to be influenced by weight gains as well as by body weight. -a weight gain of more than 10 pounds (4.5 kilograms) after the age of 18 doubles the risk of developing diabetes, even in women of average weight. -in contrast, weight loss is effective in improving glucose tolerance and insulin resistance.36 inflammation and the metabolic syndrome chronic inflammation accompa- nies obesity, and inflammation contributes to chronic diseases.37 as a person grows fatter, lipids first fill the adipose tissue and then migrate into other tissues such as the muscles and liver.38 this accumulation of fat, especially in the abdominal region, changes the body s metabolism, resulting in insulin resistance, low hdl, high triglyc- erides, and high blood pressure.39 this cluster of symptoms collectively known as the metabolic syndrome increases the risks for diabetes, hypertension, and athero- sclerosis. -fat accumulation, especially in the abdominal region, also activates genes that code for proteins involved in inflammation.40 furthermore, although relatively few immune cells are commonly found in adipose tissue, weight gain sig- nificantly increases their number and their role in inflammation.41 elevated blood lipids whether due to obesity or to a high-fat diet also promote inflammation.42 together, these factors help to explain why chronic inflammation accompanies obe- sity and how obesity contributes to the metabolic syndrome and the progression of cardiovascular disease risk factors associ- ated with obesity: high ldl cholesterol low hdl cholesterol high blood pressure (hypertension) diabetes chapter 18 provides many more details. -metabolic syndrome is a cluster of at least three of the following risk factors: high blood pressure high blood glucose high blood triglycerides low hdl cholesterol high waist circumference proteins released from adipose tissue signal changes in the body s fat and energy status and are called adipokines. -over 50 adipokines have been identified, some of which play a role in inflammation. -insulin resistance: the condition in which a normal amount of insulin produces a subnormal effect in muscle, adipose, and liver cells, resulting in an elevated fasting glucose; a metabolic consequence of obesity that precedes type 2 diabetes. -inflammation: an immunological response to cellular injury characterized by an increase in white blood cells. -266 chapter 8 chronic diseases.43 even in healthy youngsters, body fat correlates positively with chronic inflammation.44 as might be expected, weight loss reduces the number of im- mune cells in adipose tissue and changes gene expression to reduce inflammation.45 cancer the risk of some cancers increases with both body weight and weight gain, but re- searchers do not fully understand the relationships. -one possible explanation may be that obese people have elevated levels of hormones that could influence cancer development.46 for example, adipose tissue is the major site of estrogen synthesis in women, obese women have elevated levels of estrogen, and estrogen has been im- plicated in the development of cancers of the female reproductive system cancers that account for half of all cancers in women. -fit and fat versus sedentary and slim importantly, bmi and weight gains and losses do not tell the whole story. -cardiorespiratory fitness also plays a major role in health and longevity, independently of bmi.47 normal-weight people who are fit have a lower risk of mortality than normal-weight people who are unfit. -furthermore, over- weight but fit people have lower risks than normal-weight, unfit ones.48 clearly, a healthy body weight is good, but it may not be good enough. -fitness, in and of itself, offers many health benefits, as chapter 14 confirms. -the next chapter explores weight management and the benefits of achieving and maintaining a healthy weight. -k c i n t r o p r e f i n n e j f o y s e t r u o c , n o s p m a s e o j being active even if overweight is healthier than being sedentary. -with a bmi of 36, aero- bics instructor jennifer portnick is considered obese, but her daily workout routine helps to keep her in good health. -in summary the weight appropriate for an individual depends largely on factors specific to that individual, including body fat distribution, family health history, and current health status. -at the extremes, both overweight and underweight carry clear risks to health. -www.thomsonedu.com/thomsonnow nutrition portfolio when combined with fitness, a healthy body weight will help you to defend against chronic diseases. -describe how your daily food intake and physical activity balance with each other. -calculate your estimated energy requirements. -describe any health risks that may be of concern for a person of your bmi and waist circumference. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 8, then to nutrition on the net. -obtain food composition data from the usda nutrient data laboratory: www.ars.usda.gov/ba/bhnrc/ndl learn about the 10,000 steps program at shape up america: www.shapeup.org visit the special web pages and interactive applications for healthy weight: www.nhlbi.nih.gov/subsites/ index.htm nutrition calculations for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 8, then to nutrition calculations. -energy balance and body composition 267 these problems give you practice in estimating energy needs. -once you have mastered these examples, you will be pre- pared to examine your own energy intakes and energy ex- penditures. -be sure to show your calculations for each problem and check p. 269 for answers. -1. compare the energy a person might spend on various physical activities. -refer to table 8-2 on p. 255, and com- pute how much energy a person who weighs 142 pounds (64.4 kilograms) would spend doing each of the follow- ing. -you may want to compare various activities based on your weight. -30 min vigorous aerobic dance: 0.062 kcal/lb/min (cid:2) 142 lb (cid:5) 8.8 kcal/min (or 0.136 kcal/kg/min x 64.5 kg = 8.8 kcal/min) 8.8 kcal/min (cid:2) 30 min (cid:5) 264 kcal a. -2 hours golf, carrying clubs b. -20 minutes running at 9 mph study questions c. 45 minutes swimming at 20 yd/min d. 1 hour walking at 3.5 mph 2. consider the effect of age on bmr. -an infant who weighs 20 pounds (9.1 kilograms) has a bmr of 500 kcalories/day; an adult who weighs 170 pounds (77.3 kilograms) has a bmr of about 1500. based on body weight, who has the faster bmr? -3. compute daily energy needs for a woman, age 20, who is 5 feet 6 inches tall (1.68 meters), weighs 130 pounds (59 kilograms), and is lightly active. -4. discover what weight is needed to achieve a desired bmi. -refer to the table on p. 261 and consider a person who is 5 feet 4 inches (1.63 meters) tall. -suppose this person wants to have a bmi of 21. what should this person weigh? -does this agree with the table on the inside back cover? -to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -c. lose 4 to 5 pounds. -d. gain 4 to 5 pounds. -these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. what are the consequences of an unbalanced energy budget? -(pp. -249 250) 2. define hunger, appetite, satiation, and satiety and de- scribe how each influences food intake. -(pp. -251 253) 3. describe each component of energy expenditure. -what factors influence each? -how can energy expenditure be estimated? -(pp. -253 257) 4. distinguish between body weight and body composi- tion. -what assessment techniques are used to measure each? -(pp. -258 264) 5. what problems are involved in defining ideal body weight? -(pp. -258 259) 6. what is central obesity, and what is its relationship to disease? -(pp. -262 265) 7. what risks are associated with excess body weight and excess body fat? -(pp. -265 266) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 269. -1. a person who consistently consumes 1700 kcalories a day and spends 2200 kcalories a day for a month would be expected to: a. lose 1 2 to 1 pound. -b. gain 1 2 to 1 pound. -2. a bomb calorimeter measures: a. physiological fuel. -b. energy available from foods. -c. kcalories a person derives from foods. -d. heat a person releases in basal metabolism. -3. the psychological desire to eat that accompanies the sight, smell, or thought of food is known as: a. hunger. -b. satiety. -c. appetite. -d. palatability. -4. a person watching television after dinner reaches for a snack during a commercial in response to: a. external cues. -b. hunger signals. -c. stress arousal. -d. satiety factors. -5. the largest component of energy expenditure is: a. basal metabolism. -b. physical activity. -c. indirect calorimetry. -d. thermic effect of food. -6. a major factor influencing bmr is: a. hunger. -b. food intake. -c. body composition. -d. physical activity. -268 chapter 8 7. the thermic effect of an 800-kcalorie meal is about: 9. which of the following reflects height and weight? -a. -8 kcalories b. -80 kcalories c. 160 kcalories d. 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american medical association 292 (2004): 1179-1187; t. s. church and coauthors, exercise capac- ity and body composition as predictors of mortality among men with diabetes, dia- betes care 27 (2004): 83-88; s. w. farrell and coauthors, the relation of body mass index, cardiorespiratory fitness, and all-cause mortality in women, obesity research 10 (2002): 417-423; c. d. lee and s. n. blair, cardiorespiratory fitness and smoking- related and total cancer mortality in men, medicine and science in sports and exercise 34 (2002): 735-739; c. d. lee and s. n. blair, cardiorespiratory fitness and stroke mortal- ity in men, medicine and science in sports and exercise 34 (2002): 592-595. -48. f. b. hu and coauthors, adiposity as com- pared with physical activity in predicting mortality among women, new england journal of medicine 351 (2004): 2694-2703. answers nutrition calculations 1. a. -0.045 kcal/lb/min (cid:2) 142 lb (cid:5) 6.4 kcal/min 6.4 kcal/min (cid:2) 120 min (cid:5) 768 kcal b. -0.103 kcal/lb/min (cid:2) 142 lb (cid:5) 14.6 kcal/min 14.6 kcal/min (cid:2) 20 min (cid:5) 292 kcal c. 0.032 kcal/lb/min (cid:2) 142 lb (cid:5) 4.5 kcal/min 4.5 kcal/min (cid:2) 45 min (cid:5) 203 kcal d. 0.035 kcal/lb/min (cid:2) 142 lb (cid:5) 5 kcal/min 5 kcal/min (cid:2) 60 min (cid:5) 300 kcal a bmr of 8.8 kcal/lb, the infant s bmr is almost 3 times faster than the adult s based on body weight. -3. eer (cid:5) [354 (cid:6) (6.91 (cid:2) 20)] (cid:7) 1.12 (cid:2) [(9.36 (cid:2) 59) (cid:7) (726 (cid:2) 1.68)] eer (cid:5) (354 (cid:6) 138.2) (cid:7) 1.12 (552.24 (cid:7) 1219.68) eer (cid:5) (354 (cid:6) 138.2) (cid:7) 1.12 (cid:2) 1771.9 eer (cid:5) 215.8 (cid:7) 1984.6 (cid:5) 2200 kcal/day 4. -21 (cid:8) 0.172 (cid:5) 122 lb., yes 2. the infant has the faster bmr (500 kcal/day (cid:8) 20 lb (cid:5) 25 kcal/lb/day and 1500 kcal/day (cid:8) 170 lb (cid:5) 8.8 kcal/lb/day). -because the infant has a bmr of 25 kcal/lb, whereas the adult has study questions (multiple choice) 1. c 9. a 2. b 3. c 4. a 5. a 6. c 7. b 8. b 10. d highlight 8 eating disorders s e g a m i y t t e g / k n a b for some people, low body weight becomes an obsessive goal, and they begin to view normal healthy body weight as being too fat. -their efforts to lose weight progress to a dan- gerously unhealthy point. -an estimated 5 million people in the united states, primarily girls and young women, suffer from the eat- ing disorders anorexia nervosa and bulimia nervosa (the accompanying glossary defines these and related terms).1 many more suffer from binge-eating disorders or other unspecified conditions that, even though they do not meet the strict criteria for anorexia nervosa or bulimia ner- vosa, imperil a person s well-being. -why do so many people in our society suffer from eating dis- orders? -most experts agree that the causes include multiple fac- tors: sociocultural, psychological, and perhaps neurochemical. -excessive pressure to be thin is at least partly to blame. -young people who attempt extreme weight loss may have learned to identify discomforts such as anger, jealousy, or disappointment with feeling fat. -they may also be depressed or suffer social anxiety. -as weight loss becomes more of a focus, psychological problems worsen, and the likelihood of developing eating disor- ders intensifies. -athletes are among those most likely to develop eating disorders. -the female athlete triad at age 14, suzanne was a top contender for a spot on the state gymnastics team. -each day her coach reminded team members e g a m i f r o d e i n e v e t s e h t / y h p a r g o t o h p that they must weigh no more than their as- signed weights to qualify for competition. -the coach chastised gymnasts who gained weight, and suzanne was terrified of being singled out. -convinced that the less she weighed the better she would perform, suzanne weighed herself several times a day to confirm that she had not exceeded her 80- pound limit. -driven to excel in her sport, suzanne kept her weight down by eating very little and training very hard. -unlike many of her friends, suzanne never began to menstruate. -a few months before her fifteenth birthday, suzanne s coach dropped her back to the second-level team. -suzanne blamed her poor performance on a slow-healing stress fracture. -mentally stressed and physically exhausted, she quit gymnastics and began overeating between periods of self-starva- tion. -suzanne had developed the dangerous combination of problems that characterize the female athlete triad disor- dered eating, amenorrhea, and osteoporosis (see figure h8-1).2 disordered eating part of the reason many athletes engage in disordered eating behaviors may be that they and their coaches have embraced un- suitable weight standards. -an athlete s body must be heavier for a given height than a nonathlete s body because the athlete s body is dense, containing more healthy bone and muscle and less fat. -when athletes rely only on the scales, they may mistakenly believe they are too fat because weight standards, such as the bmi, do not provide adequate information about body composition. -g lossary amenorrhea (ay-men-oh-ree- ah): the absence of or cessation of menstruation. -primary amenorrhea is menarche delayed beyond 16 years of age. -secondary amenorrhea is the absence of three to six consecutive menstrual cycles. -anorexia (an-oh-reck-see-ah) nervosa: an eating disorder characterized by a refusal to maintain a minimally normal body weight and a distortion in perception of body shape and weight. -an (cid:5) without 270 orex (cid:5) mouth nervos (cid:5) of nervous origin binge-eating disorder: an eating disorder with criteria similar to those of bulimia nervosa, excluding purging or other compensatory behaviors. -bulimia (byoo-leem-ee-ah) nervosa: an eating disorder characterized by repeated episodes of binge eating usually followed by self-induced vomiting, misuse of laxatives or diuretics, fasting, or excessive exercise. -buli (cid:5) ox cathartic (ka-thar-tik): a strong laxative. -disordered eating: eating behaviors that are neither normal nor healthy, including restrained eating, fasting, binge eating, and purging. -eating disorders: disturbances in eating behavior that jeopardize a person s physical or psycho- logical health. -emetic (em-ett-ic): an agent that causes vomiting. -female athlete triad: a potentially fatal combination of three medical problems disordered eating, amenorrhea, and osteoporosis. -muscle dysmorphia (dis-more- fee-ah): a psychiatric disorder characterized by a preoccupa- tion with building body mass. -stress fractures: bone damage or breaks caused by stress on bone surfaces during exercise. -unspecified eating disorders: eating disorders that do not meet the defined criteria for specific eating disorders. -figure h8-1 the female athlete triad eating disorder restrictive dieting (inadequate energy and nutrient intake) overexercising weight loss lack of body fat osteoporosis amenorrhea loss of calcium from bones diminished hormones many young athletes severely restrict energy intakes to im- prove performance, enhance the aesthetic appeal of their perfor- mance, or meet the weight guidelines of their specific sports. -they fail to realize that the loss of lean tissue that accompanies energy restriction actually impairs their physical performance. -the increasing incidence of abnormal eating habits among ath- letes is cause for concern. -male athletes, especially wrestlers and gymnasts, are affected by these disorders as well, but females are most vulnerable. -risk factors for eating disorders among athletes include: young age (adolescence) pressure to excel at a chosen sport focus on achieving or maintaining an ideal body weight or body fat percentage participation in sports or competitions that emphasize a lean appearance or judge performance on aesthetic appeal such as gymnastics, wrestling, figure skating, or dance3 weight-loss dieting at an early age unsupervised dieting i s b r o c / . -c n i a i d e m w e n s r e t u e r a few years ago, this olympic gold medalist was weak and malnourished from anorexia nervosa. -however, she recovered and set a world record in the cycling road race. -eating disorders 271 amenorrhea the prevalence of amenorrhea among premenopausal women in the united states is about 2 to 5 percent overall, but among fe- male athletes, it may be as high as 66 percent. -contrary to previ- ous notions, amenorrhea is not a normal adaptation to strenuous physical training: it is a symptom of something going wrong.4 amenorrhea is characterized by low blood estrogen, infertility, and often bone mineral losses. -excessive training, depleted body fat, low body weight, and inadequate nutrition all contribute to amenorrhea. -however amenorrhea develops, it threatens the in- tegrity of the bones. -bone losses remain significant even after re- covery. -(women with bulimia frequently have menstrual irregularities, but because they rarely cease menstruating, they may be spared this loss of bone integrity.5) osteoporosis for most people, weight-bearing physical activity, dietary cal- cium, and (for women) the hormone estrogen protect against the bone loss of osteoporosis. -for young women with disordered eat- ing and amenorrhea, strenuous activity can impair bone health. -vigorous training combined with inadequate food intake disrupts metabolic and hormonal balances.6 these disturbances compro- mise bone health, greatly increasing the risks of stress fractures today and of osteoporosis in later life. -stress fractures, a serious form of bone injury, commonly occur among dancers and other athletes with amenorrhea, low calcium intakes, and disordered eating. -many underweight young athletes have bones like those of postmenopausal women, and they may never recover their lost bone even after diagnosis and treatment which makes preven- tion critical. -young athletes should be encouraged to consume 1300 milligrams of calcium each day, to eat nutrient-dense foods, and to obtain enough energy to support both weight gain and the energy expended in physical activity. -other dangerous practices of athletes only females face the threats of the female athlete triad, of course, but many male athletes face pressure to achieve a certain body weight and may develop eating disorders. -each week throughout the season, david drastically restricts his food and fluid intake before a wrestling match in an effort to make weight. -wrestlers and their coaches believe that competing in a lower weight class will give them a competitive advantage over smaller opponents. -to that end, david practices in rubber suits, sits in saunas, and takes diuretics to lose 4 to 6 pounds. -he hopes to replenish the lost fluids, glycogen, and lean tissue during the hours between his weigh-in and competition, but the body needs days to correct this metabolic mayhem. -reestablishing fluid and electrolyte balances may take a day or two, replenishing glycogen stores may take two to three days, and replacing lean tissue may take even longer. -272 highlight 8 highlight 3 ironically, the combination of food deprivation and dehydra- tion impairs physical performance by reducing muscle strength, decreasing anaerobic power, and reducing endurance capacity. -for optimal performance, wrestlers need to first achieve their competitive weight during the off-season and then eat well- balanced meals and drink plenty of fluids during the competitive season. -some athletes go to extreme measures to bulk up and gain weight. -people afflicted with muscle dysmorphia eat high-pro- tein diets, take dietary supplements, weight train for hours at a time, and often abuse steroids in an attempt to bulk up. -their bodies are large and muscular, yet they see themselves as puny 90-pound weaklings. -they are preoccupied with the idea that their bodies are too small or inadequately muscular. -like others with distorted body images, people with muscle dysmorphia weigh themselves frequently and center their lives on diet and ex- ercise. -paying attention to diet and pumping iron for fitness is ad- mirable, but obsessing over it can cause serious social, occupational, and physical problems. -preventing eating disorders in athletes to prevent eating disorders in athletes and dancers, the perform- ers, their coaches, and their parents must learn about inappropri- ate body weight ideals, improper weight-loss techniques, eating disorder development, proper nutrition, and safe weight-control methods. -young people naturally search for identity and will of- ten follow the advice of a person in authority without question. -therefore, coaches and dance instructors should never encourage unhealthy weight loss to qualify for competition or to conform to distorted artistic ideals. -athletes who truly need to lose weight should try to do so during the off-season and under the supervi- sion of a health care professional. -frequent weighings can push young people who are striving to lose weight into a cycle of starv- ing to confront the scale, then bingeing uncontrollably afterward. -the erosion of self-esteem that accompanies these events can in- terfere with normal psychological development and set the stage for serious problems later on. -table h8-1 includes suggestions to help athletes and dancers protect themselves against developing eating disorders. -the re- maining sections describe eating disorders that anyone, athlete or nonathlete, may experience. -anorexia nervosa julie, 18 years old, is a superachiever in school. -she watches her diet with great care, and she exercises daily, maintaining a rigor- ous schedule of self-discipline. -she is thin, but she is determined to lose more weight. -she is 5 feet 6 inches tall and weighs 85 pounds (roughly 1.68 meters and 39 kilograms). -she has anorexia nervosa. -table h8-1 tips for combating eating disorders general guidelines never restrict food amounts to below those suggested for adequacy by the usda food guide (see table 2-3 on p. 41). -eat frequently. -include healthy snacks between meals. -the person who eats frequently never gets so hungry as to allow hunger to dictate food choices. -if not at a healthy weight, establish a reasonable weight goal based on a healthy body composition. -allow a reasonable time to achieve the goal. -a reasonable loss of excess fat can be achieved at the rate of about 10 percent of body weight in six months. -establish a weight-maintenance support group with people who share interests. -specific guidelines for athletes and dancers replace weight-based goals with performance-based goals. -restrict weight-loss activities to the off-season. -remember that eating disorders impair physical performance. -seek confidential help in obtaining treatment if needed. -focus on proper nutrition as an important facet of your training, as important as proper technique. -characteristics of anorexia nervosa julie is unaware that she is undernourished, and she sees no need to obtain treatment. -she developed amenorrhea several months ago and has become moody and chronically depressed. -she in- sists that she is too fat, although her eyes are sunk in deep hollows in her face. -julie denies that she is ever tired, although she is close to physical exhaustion and no longer sleeps easily. -her family is concerned, and though reluctant to push her, they have finally in- sisted that she see a psychiatrist. -julie s psychiatrist has diagnosed anorexia nervosa (see table h8-2) and prescribed group therapy as a start. -if she does not begin to gain weight soon, she may need to be hospitalized. -as mentioned in the introduction, most anorexia nervosa vic- tims are females; males account for only about 1 in 20 reported cases. -central to the diagnosis of anorexia nervosa is a distorted body image that overestimates personal body fatness. -when julie looks at herself in the mirror, she sees a fat 85-pound body. -the more julie overestimates her body size, the more resistant she is to treatment, and the more unwilling to examine her faulty values and misconceptions. -malnutrition is known to affect brain func- tioning and judgment in this way, causing lethargy, confusion, and delirium. -anorexia nervosa cannot be self-diagnosed. -many people in our society are engaged in the pursuit of thinness, and denial runs high among people with anorexia nervosa. -some women have all the attitudes and behaviors associated with the condition, but without the dramatic weight loss. -self-starvation how can a person as thin as julie continue to starve herself? -julie uses tremendous discipline against her hunger to strictly limit her portions of low-kcalorie foods. -she will deny her hunger, and having adapted to so little food, she feels full af- eating disorders 273 loss of digestive functions that worsens malnutrition. -peristalsis becomes sluggish, the stomach empties slowly, and the lining of the intestinal tract atrophies. -the deteriorated gi tract fails to pro- vide sufficient digestive enzymes and absorptive surfaces for han- dling any food that is eaten. -the pancreas slows its production of digestive enzymes. -the person may suffer from diarrhea, further worsening malnutrition. -other effects of starvation include altered blood lipids, high blood vitamin a and vitamin e, low blood proteins, dry thin skin, abnormal nerve functioning, reduced bone density, low body temperature, low blood pressure, and the development of fine body hair (the body s attempt to keep warm). -the electrical activ- ity of the brain becomes abnormal, and insomnia is common. -both women and men lose their sex drives. -women with anorexia nervosa develop amenorrhea. -(it is one of the diagnostic criteria.) -in young girls, the onset of menstrua- tion is delayed. -menstrual periods typically resume with recovery, although some women never restart even after they have gained weight. -should an underweight woman with anorexia nervosa become pregnant, she is likely to give birth to an underweight baby and low-birthweight babies face many health problems (as chapter 15 explains). -mothers with anorexia nervosa may un- derfeed their children who then fail to grow and may also suffer the other consequences of starvation. -treatment of anorexia nervosa treatment of anorexia nervosa requires a multidisciplinary ap- proach.10 teams of physicians, nurses, psychiatrists, family thera- pists, and dietitians work together to resolve two sets of issues and behaviors: those relating to food and weight and those in- volving relationships with oneself and others. -the first dietary ob- jective is to stop weight loss while establishing regular eating patterns. -appropriate diet is crucial to recovery and must be tai- lored to individual client s needs. -because body weight is low and fear of weight gain is high, initial food intake may be small per- haps only 1200 kcalories per day.11 as eating becomes more com- fortable, clients should gradually increase energy intake. -initially, clients may be unwilling to eat for themselves. -those who do eat will have a good chance of recovering without additional inter- ventions. -even after recovery, however, energy intakes and eating behaviors may not fully return to normal.12 furthermore, weight gains may be slow because energy needs may be slightly elevated due to anxiety, abdominal pain, and cigarette smoking.13 because anorexia nervosa is like starvation physically, health care professionals classify clients based on indicators of pem. -* low-risk clients need nutrition counseling. -intermediate-risk clients may need supplements such as high-kcalorie, high-protein formulas in addition to regular meals. -high-risk clients may re- quire hospitalization and may need to be fed by tube at first to prevent death. -this step may cause psychological trauma. -al- though drugs are commonly prescribed, they play a limited role in treatment. -* indicators of protein-energy malnutrition: a low percentage of body fat, low serum albumin, low serum transferrin, and impaired immune reactions. -text not available due to copyright restrictions ter eating only a half-dozen carrot sticks. -she knows the kcalorie contents of dozens of foods and the kcalorie costs of as many ex- ercises. -if she feels that she has gained an ounce of weight, she runs or jumps rope until she is sure she has exercised it off. -if she fears that the food she has eaten outweighs the exercise, she may take laxatives to hasten the passage of food from her system. -she drinks water incessantly to fill her stomach, risking dangerous mineral imbalances. -she is desperately hungry. -in fact, she is starving, but she doesn t eat because her need for self-control dominates. -many people, on learning of this disorder, say they wish they had a touch of it to get thin. -they mistakenly think that people with anorexia nervosa feel no hunger. -they also fail to recognize the pain of the associated psychological and physical trauma. -physical consequences the starvation of anorexia nervosa damages the body just as the starvation of war and poverty does. -in fact, after a few months, most people with anorexia nervosa have protein-energy malnutrition (pem) that is similar to maras- mus (described in chapter 6).7 their bodies have been depleted of both body fat and protein.8 victims are dying to be thin quite literally. -in young people, growth ceases and normal develop- ment falters. -they lose so much lean tissue that basal metabolic rate slows. -in addition, the heart pumps inefficiently and irregu- larly, the heart muscle becomes weak and thin, the chambers di- minish in size, and the blood pressure falls.9 minerals that help to regulate heartbeat become unbalanced. -many deaths occur due to multiple organ system failure when the heart, kidneys, and liver cease to function. -starvation brings other physical consequences as well, such as loss of brain tissue, impaired immune response, anemia, and a 274 highlight 8 highlight 3 denial runs high among those with anorexia nervosa. -few seek treatment on their own. -about half of the women who are treated can maintain their body weight at 85 percent or more of a healthy weight, and at that weight, many of them begin men- struating again.14 the other half have poor to fair treatment out- comes, relapse into abnormal eating behaviors, or die. -anorexia nervosa has one of the highest mortality rates among psychiatric disorders.15 an estimated 1000 women die each year of anorexia nervosa most commonly from cardiac complications due to malnutrition or by suicide.16 before drawing conclusions about someone who is extremely thin or who eats very little, remember that diagnosis requires pro- fessional assessment. -several national organizations offer informa- tion for people who are seeking help with anorexia nervosa, either for themselves or for others. -* bulimia nervosa kelly is a charming, intelligent, 30-year-old flight attendant of normal weight who thinks constantly about food. -she alternates between starving herself and secretly bingeing, and when she has eaten too much, she makes herself vomit. -most readers recognize these symptoms as those of bulimia nervosa. -characteristics of bulimia nervosa bulimia nervosa is distinct from anorexia nervosa and is more prevalent, although the true incidence is difficult to establish be- cause bulimia nervosa is not as physically apparent. -more men suffer from bulimia nervosa than from anorexia nervosa, but bu- limia nervosa is still more common in women than in men. -the secretive nature of bulimic behaviors makes recognition of the problem difficult, but once it is recognized, diagnosis is based on the criteria listed in table h8-3. -like the typical person with bulimia nervosa, kelly is single, fe- male, and white. -she is well educated and close to her ideal body weight, although her weight fluctuates over a range of 10 pounds or so every few weeks. -she prefers to weigh less than the weight that her body maintains naturally. -kelly seldom lets her eating disorder interfere with work or other activities, although a third of all bulimics do. -from early childhood, she has been a high achiever and emotionally de- pendent on her parents. -as a young teen, kelly frequently fol- lowed severely restricted diets but could never maintain the weight loss. -kelly feels anxious at social events and cannot easily establish close personal relationships. -she is usually depressed, is often impulsive, and has low self-esteem. -when crisis hits, kelly responds by replaying events, worrying excessively, and blaming herself but never asking for help behaviors that interfere with ef- fective coping. -binge eating like the person with anorexia nervosa, the person with bulimia nervosa spends much time thinking about body weight and food. -the preoccupation with food manifests itself in * internet sites are listed at the end of this highlight. -table h8-3 criteria for diagnosis of bulimia nervosa a person with bulimia nervosa demonstrates the following: a. recurrent episodes of binge eating. -an episode of binge eating is char- acterized by both of the following: 1. eating, in a discrete period of time (e.g., within any two-hour pe- riod), an amount of food that is definitely larger than most people would eat during a similar period of time and under similar circum- stances. -2. a sense of lack of control over eating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating). -b. recurrent inappropriate compensatory behavior to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, enemas, or other medications; fasting; or excessive exercise. -c. binge eating and inappropriate compensatory behaviors both occur, on average, at least twice a week for three months. -d. self-evaluation unduly influenced by body shape and weight. -e. the disturbance does not occur exclusively during episodes of anorexia nervosa. -two types: purging type: the person regularly engages in self-induced vomiting or the misuse of laxatives, diuretics, or enemas. -nonpurging type: the person uses other inappropriate compensatory behaviors, such as fasting or excessive exercise, but does not regularly engage in self-induced vomiting or the misuse of laxatives, diuretics, or enemas. -source: reprinted with permission from american psychiatric association, diagnostic and statistical manual of mental disorders, 4th ed. -text revision. -(washington, d.c.: american psychiatric association, 2000). -secret binge-eating episodes, which usually progress through sev- eral emotional stages: anticipation and planning, anxiety, urgency to begin, rapid and uncontrollable consumption of food, relief and relaxation, disappointment, and finally shame or disgust. -a bulimic binge is characterized by a sense of lacking control over eating. -during a binge, the person consumes food for its emotional comfort and cannot stop eating or control what or how much is eaten. -a typical binge occurs periodically, in secret, usually at night, and lasts an hour or more. -because a binge fre- quently follows a period of rigid dieting, eating is accelerated by intense hunger. -energy restriction followed by bingeing can set in motion a pattern of weight cycling, which may make weight loss and maintenance more difficult over time. -during a binge, kelly consumes thousands of kcalories of easy- to-eat, low-fiber, high-fat, and, especially, high-carbohydrate foods. -typically, she chooses cookies, cakes, and ice cream and she eats the entire bag of cookies, the whole cake, and every last spoonful in a carton of ice cream. -after the binge, kelly pays the price with swollen hands and feet, bloating, fatigue, headache, nausea, and pain. -purging to purge the food from her body, kelly may use a cathartic a strong laxative that can injure the lower intestinal tract. -or she may induce vomiting, with or without the use of an emetic a drug intended as first aid for poisoning. -these purg- ing behaviors are often accompanied by feelings of shame or guilt. -hence a vicious cycle develops: negative self-perceptions eating disorders 275 stomach. -sometimes the eyes become red from pressure during vomiting. -the hands may be calloused or cut by the teeth while inducing vomiting. -overuse of emetics depletes potassium con- centrations and can lead to death by heart failure. -unlike julie, kelly is aware that her behavior is abnormal, and she is deeply ashamed of it. -she wants to recover, and this makes recov- ery more likely for her than for julie, who clings to denial. -feeling inadequate ( i can t even control my eating ), kelly tends to be passive and to look to others for confirmation of her sense of worth. -when she experiences rejection, either in reality or in her imagina- tion, her bulimia nervosa becomes worse. -if kelly s depression deepens, she may seek solace in drug or alcohol abuse or in other addictive behaviors. -clinical depression is common in people with bulimia nervosa, and the rates of substance abuse are high.17 treatment of bulimia nervosa kelly needs to establish regular eating patterns. -she may also ben- efit from a regular exercise program.18 weight maintenance, rather than cyclic weight gains and losses, is the treatment goal. -major steps toward recovery include discontinuing purging and restrictive dieting habits and learning to eat three meals a day plus snacks.19 initially, energy intake should provide enough food to satisfy hunger and maintain body weight. -table h8-4 offers diet strategies to correct the eating problems of bulimia nervosa. -about half of the women diagnosed with bulimia nervosa recover table h8-4 nervosa diet strategies for combating bulimia planning principles plan meals and snacks; record plans in a food diary prior to eating. -plan meals and snacks that require eating at the table and using utensils. -refrain from finger foods. -refrain from dieting or skipping meals. -nutrition principles eat a well-balanced diet and regularly timed meals consisting of a variety of foods. -include raw vegetables, salad, or raw fruit at meals to prolong eating times. -choose whole-grain, high-fiber breads, pasta, rice, and cereals to increase bulk. -consume adequate fluid, particularly water. -other tips choose foods that provide protein and fat for satiety and bulky, fiber- rich carbohydrates for immediate feelings of fullness. -try including soups and other water-rich foods for satiety. -choose portions that meet the definition of a serving according to the daily food guide (pp. -42 43). -for convenience (and to reduce temptation) select foods that naturally divide into portions. -select one potato, rather than rice or pasta that can be overloaded onto the plate; purchase yogurt and cottage cheese in individual containers; look for small packages of precut steak or chicken; choose frozen dinners with measured portions. -include 30 minutes of physical activity every day exercise may be an important tool in defeating bulimia. -t i d e o t o h p / n a m w e n l e a h c i m bulimic binges are often followed by self- induced vomiting and feelings of shame or disgust. -followed by dieting, bingeing, and purging, which in turn lead to negative self-perceptions (see figure h8-2). -on first glance, purging seems to offer a quick and easy solu- tion to the problems of unwanted kcalories and body weight. -many people perceive such behavior as neutral or even positive, when, in fact, binge eating and purging have serious physical consequences. -signs of subclinical malnutrition are evident in a compromised immune system. -fluid and mineral imbalances caused by vomiting or diarrhea can lead to abnormal heart rhythms and injury to the kidneys. -urinary tract infections can lead to kidney failure. -vomiting causes irritation and infection of the pharynx, esophagus, and salivary glands; erosion of the teeth; and dental caries. -the esophagus may rupture or tear, as may the figure h8-2 and binge eating the vicious cycle of restrictive dieting negative self-perceptions purging restrictive dieting binge eating 276 highlight 8 highlight 3 completely after five to ten years, with or without treatment, but treatment probably speeds the recovery process. -a mental health professional should be on the treatment team to help clients with their depression and addictive behaviors. -some physicians prescribe the antidepressant drug fluoxetine in the treatment of bulimia nervosa. -* another drug that may be use- ful in the management of bulimia nervosa is naloxone, an opiate antagonist that suppresses the consumption of sweet and high- fat foods in binge-eaters. -anorexia nervosa and bulimia nervosa are distinct eating disor- ders, yet they sometimes overlap in important ways. -anorexia vic- tims may purge, and victims of both disorders may be overly concerned with body weight and have a tendency to drastically undereat. -many perceive foods as forbidden and give in to an eating binge. -the two disorders can also appear in the same person, or one can lead to the other. -treatment is challenging and relapses are not unusual. -other people have unspecified eating disorders that fall short of the criteria for anorexia ner- vosa or bulimia nervosa but share some of their features. -one such condition is binge-eating disorder. -binge-eating disorder charlie is a 40-year-old schoolteacher who has been overweight all his life. -his friends and family are forever encouraging him to lose weight, and he has come to believe that if he only had more willpower, dieting would work. -he periodically gives dieting his best shot restricting energy intake for a day or two only to suc- cumb to uncontrollable cravings, especially for high-fat foods. -like charlie, up to half of the obese people who try to lose weight periodically binge; unlike people with bulimia nervosa, however, they typically do not purge. -such an eating disorder does not meet the criteria for either anorexia nervosa or bulimia nervosa yet such compulsive overeating is a problem and occurs in people of normal weight as well as those who are severely overweight. -table h8-5 lists criteria for unspecified eating disorders, including binge eating. -obesity alone is not an eating disorder. -clinicians note differences between people with bulimia nervosa and those with binge-eating disorder.20 people with binge-eating disorder consume less during a binge, rarely purge, and exert less restraint during times of dieting. -similarities also exist, including feeling out of control, disgusted, depressed, embarrassed, guilty, or distressed because of their self-perceived gluttony.21 * fluoxetine is marketed under the trade name prozac. -there are also differences between obese binge-eaters and obese people who do not binge. -those with the binge-eating dis- order report higher rates of self-loathing, disgust about body size, depression, and anxiety. -their eating habits differ as well. -obese binge-eaters tend to consume more kcalories and more dessert and snack-type foods during regular meals and binges than obese people who do not binge. -binge eating is a behavioral disorder that can be resolved with treatment. -resolving such behavior may not bring weight loss, but it may make participation in weight-control programs easier. -it also improves physical health, mental health, and the chances of success in breaking the cycle of rapid weight losses and gains. -eating disorders in society proof that society plays a role in eating disorders is found in their demographic distribution they are known only in developed na- tions, and they become more prevalent as wealth increases and food becomes plentiful. -some people point to the vomitoriums of ancient times and claim that bulimia nervosa is not new, but the two are actually distinct. -ancient people were eating for pleasure, without guilt, and in the company of others; they vomited so that they could rejoin the feast. -bulimia nervosa is a disorder of isola- tion and is often accompanied by low self-esteem. -chapter 8 described how our society sets unrealistic ideals for body weight, especially in women, and devalues those who do not conform to them. -anorexia nervosa and bulimia nervosa are not a form of rebellion against these unreasonable expectations, but rather an exaggerated acceptance of them. -in fact, body dis- satisfaction is a primary factor in the development of eating disor- ders.22 not everyone who is dissatisfied will develop an eating disorder, but everyone with an eating disorder is dissatisfied. -characteristics of disordered eating such as restrained eating, fasting, binge eating, purging, fear of fatness, and distortion of body image are extraordinarily common among young girls. -most are on diets, and many are poorly nourished. -some eat too little food to support normal growth; thus they miss out on their adolescent growth spurts and may never catch up. -many eat so little that hunger propels them into binge-purge cycles. -perhaps a person s best defense against these disorders is to learn to appreciate his or her own uniqueness. -when people dis- cover and honor their body s real physical needs, they become unwilling to sacrifice health for conformity. -to respect and value oneself may be lifesaving. -eating disorders 277 table h8-5 unspecified eating disorders, including binge-eating disorder criteria for diagnosis of unspecified eating disorders, in general many people have eating disorders but do not meet all the criteria to be classified as having anorexia nervosa or bulimia nervosa. -some examples include those who: a. meet all of the criteria for anorexia nervosa, except irregular menses. -b. meet all of the criteria for anorexia nervosa, except that their current weights fall within the normal ranges. -c. meet all of the criteria for bulimia nervosa, except that binges occur less frequently than stated in the criteria. -d. are of normal body weight and who compensate inappropriately for eating small amounts of food (example: self-induced vomiting after eating two cookies). -e. repeatedly chew food but spit it out without swallowing. -f. have recurrent episodes of binge eating but do not compensate as do those with bulimia nervosa. -criteria for diagnosis of binge-eating disorder, specifically a person with a binge-eating disorder demonstrates the following: a. recurrent episodes of binge eating. -an episode of binge eating is characterized by both of the following: 1. eating, in a discrete period of time (e.g., within any two-hour period) an amount of food that is definitely larger than most people would eat in a similar period of time under similar circumstances. -2. a sense of lack of control over eating during the episode (e.g., a feeling that one cannot stop eating or control what or how much one is eating). -b. binge-eating episodes are associated with at least three of the following: 1. eating much more rapidly than normal. -2. eating until feeling uncomfortably full. -3. eating large amounts of food when not feeling physically hungry. -4. eating alone because of being embarrassed by how much one is eating. -5. feeling disgusted with oneself, depressed, or very guilty after overeating. -c. the binge eating causes marked distress. -d. the binge eating occurs, on average, at least twice a week for six months. -e. the binge eating is not associated with the regular use of inappropriate compensatory behaviors (e.g., purging, fasting, excessive exercise) and does not occur exclusively during the course of anorexia nervosa or bulimia nervosa. -source: reprinted with permission from american psychiatric association, diagnostic and statistical manual of mental disorders, 4th ed. -text revision. -(washington, d.c.: american psychiatric association, 2000). -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 8, then to highlights nutrition on the net. -search for anorexia, bulimia, and eating disorders at the u.s. government health information site: www.healthfinder.gov learn more about anorexia nervosa and related eating disorders from anorexia nervosa and related eating dis- orders or the academy of eating disorders: www.anred.com or www.aedweb.org get facts about eating disorders from the national insti- tute of mental health: www.nimh.nih.gov/ publicat/eatingdisorders.cfm 278 highlight 8 highlight 3 references 1. position of the american dietetic associa- tion: nutrition intervention in the treat- ment of anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified (ednos), journal of the american dietetic association 101 (2001): 810-819. -2. k. kazis and e. iglesias, the female athlete triad, adolescent medicine 14 (2003): 87-95; s. sabatini, the female athlete triad, american journal of the medical sciences 322 (2001): 193-195; committee on sports medicine and fitness, medical concerns in the female athlete, pediatrics 106 (2000): 610-613. -3. m. f. reinking and l. e. alexander, preva- lence of disordered-eating behaviors in undergraduate female collegiate athletes and nonathletes, journal of athletic training 40 (2005): 47-51; m. k. torstveit and j. sundgot-borgen, the female athlete triad: are elite athletes at increased risk? -medicine & science in sports & exercise 37 (2005): 184-193. -4. n. h. golden, a review of the female ath- lete triad (amenorrhea, osteoporosis and disordered eating), international journal of adolescent medicine and health 14 (2002): 9-17. -5. s. j. crow and coauthors, long-term men- strual and reproductive function in patients with bulimia nervosa, american journal of psychiatry 159 (2002): 1048-1050. -6. c. l. zanker and c. b. cooke, energy bal- ance, bone turnover, and skeletal health in physically active individuals, medicine & science in sports & exercise 36 (2004): 1372-1381. -7. m. p. fuhrman, p. charney, and c. m. mueller, hepatic proteins and nutrition assessment, journal of the american dietetic association 104 (2004): 1258-1264. -8. k. p. kerruish and coauthors, body composi- tion in adolescents with anorexia nervosa, american journal of clinical nutrition 75 (2002): 31-37. -9. c. romano and coauthors, reduced hemo- dynamic load and cardiac hypotrophy in patients with anorexia nervosa, american journal of clinical nutrition 77 (2003): 308-312. -10. committee on adolescence, identifying and treating eating disorders, pediatrics 111 (2003): 204-211. -11. j. yager and a. e. andersen, anorexia ner- vosa, new england journal of medicine 353 (2005): 1481-1488. -12. r. sysko and coauthors, eating behavior among women with anorexia nervosa, american journal of clinical nutrition 82 (2005): 296-301; b. r. carruth and j. d. skinner, dietary and physical activity pat- terns of young females with histories of eating disorders, topics in clinical nutrition 16 (2000): 13-23. -13. v. van wymelbeke and coauthors, factors associated with the increase in resting energy expenditure during refeeding in malnourished anorexia nervosa patients, american journal of clinical nutrition 80 (2004): 1469-1477. -14. h. c. steinhausen, the outcome of anorexia nervosa in the 20th century, american journal of psychiatry 159 (2002): 1284-1293; b. lowe and coauthors, long-term outcome of anorexia nervosa in a prospective 21-year follow-up study, psychological medicine 31 (2001): 881-890. -15. p. k. keel and coauthors, predictors of mortality in eating disorders, archives of general psychiatry 60 (2003): 179-183. -16. m. b. tamburrino and r. a. mcginnis, anorexia nervosa: a review, panminerva medica 44 (2002): 301-311. -17. c. m. bulik and coauthors, alcohol use disorder comorbidity in eating disorders: a multicenter study, journal of clinical psychia- try 65 (2004): 1000-1006. -18. j. sundgot-borgen and coauthors, the effect of exercise, cognitive therapy, and nutri- tional counseling in treating bulimia ner- vosa, medicine and science in sports and exercise 34 (2002): 190-195. -19. position of the american dietetic associa- tion, 2001. -20. a. e. dingemans, m. j. bruna, and e. f. van furth, binge eating disorder: a review, international journal of obesity and related metabolic disorders 26 (2002): 299-307. -21. d. m. ackard and coauthors, overeating among adolescents: prevalence and associa- tions with weight-related characteristics and psychological health, pediatrics 111 (2003): 67-74. -22. j. polivy and c. p. herman, causes of eating disorders, annual review of psychology 53 (2002): 187-213. this page intentionally left blank alice edward/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow figure 9-1: animated! -increasing prevalence of obesity among u.s. adults figure 9-8: animated! -influence of physical activity on discretionary kcalorie allowance how to: practice problems nutrition portfolio journal nutrition calculations: practice problems nutrition in your life are you pleased with your body weight? -if so, you are a rare individual. -most people in our society think they should weigh more or less (mostly less) than they do. -usually, their primary concern is appearance, but they often understand that physical health is also somehow related to body weight. -one does not necessarily cause the other that is, an ideal body weight does not ensure good health. -instead, both depend on diet and physical activity. -a well-balanced diet and active lifestyle support good health and help maintain body weight within a reasonable range. -c h a p t e r 9 chapter outline overweight and obesity fat cell development fat cell metabolism set-point theory causes of overweight and obesity genetics environment problems of overweight and obesity health risks perceptions and prejudices dangerous interventions aggressive treatments for obesity drugs surgery weight-loss strategies eating plans physical activity environmental influences behavior and attitude weight maintenance prevention public health programs underweight problems of underweight weight-gain strategies highlight 9 the latest and greatest weight-loss diet again weight management: overweight, obesity, and underweight the previous chapter described how body weight is stable when energy in equals energy out. -weight gains occur when energy intake exceeds energy expended, and conversely, weight losses occur when energy expended ex- ceeds energy intake. -at the extremes, both overweight and underweight present health risks. -weight management is a key component of good health. -this chapter emphasizes overweight, partly because it has been more intensively studied and partly because it is a major health problem in the united states and a growing concern worldwide. -information on under- weight is presented wherever appropriate. -the highlight that follows this chapter examines fad diets. -overweight and obesity despite our preoccupation with body image and weight loss, the prevalence of over- weight and obesity in the united states continues to rise dramatically.1 in the past two decades, obesity increased in every state, in both genders, and across all ages, races, and educational levels (see figure 9-1, p. 282). -an estimated 66 percent of the adults in the united states are now considered overweight or obese, as defined by a bmi of 25 or greater.2 the prevalence of overweight is especially high among women, the poor, blacks, and hispanics. -the prevalence of overweight among children in the united states has also risen at an alarming rate. -an estimated 33 percent of children and adolescents ages 2 to 19 years are either overweight or at risk for overweight. -3 chapter and highlight 16 present information on overweight during childhood and adolescence. -bmi: underweight: (cid:2)18.5 healthy weight: 18.5 24.9 overweight: 25.0 29.9 obese: (cid:3)30 weight management: maintaining body weight in a healthy range by preventing gradual weight gain over time and losing weight if overweight. -281 282 chapter 9 figure 9-1 animated! -increasing prevalence of obesity (bmi (cid:3) 30) among u.s. adults key: no data <10% 10% 14% 15% 19% 20% 24% 25% 29% 30% to test your understanding of these concepts, log on to www .thomsonedu.com/thomsonnow 1990: no state had prevalence rates greater than or equal to 15 percent. -1995: over half the states had prevalence rates greater than or equal to 15 percent, but no state had prevalence rates greater than or equal to 20 percent. -2000: only one state had prevalence rates less than 15 percent, almost half of the states had prevalence rates greater than or equal to 20 percent, and no state had prevalence rates greater than or equal to 25 percent. -2005: only four states had prevalence rates less than 20 percent, about one-third of the states had prevalence rates greater than or equal to 25 percent, with three states having prevalence rates greater than or equal to 30 percent. -source: www.cdc.nccdphp/dnpa/obesity/trend/maps/index.htm obesity is so widespread and its prevalence is rising so rapidly that many refer to it as an epidemic.4 according to the world health organization, this epidemic of obesity has spread worldwide, affecting over 300 million adults. -contrary to popu- lar opinion, obesity is not limited to industrialized nations; over 115 million people in developing countries suffer from obesity-related problems. -before examining the suspected causes of obesity and the various strategies used to treat it, it is helpful to understand the development and metabolism of body fat. -fat cell development when more energy is consumed than is expended, much of the excess energy is stored in the fat cells of adipose tissue. -the amount of fat in a person s body reflects both the number and the size of the fat cells. -the number of fat cells increases most rapidly during the growing years of late childhood and early puberty. -after growth ceases, fat cell number may continue to increase whenever energy balance is posi- tive. -obese people have more fat cells than healthy-weight people; their fat cells are also larger. -when energy intake exceeds expenditure, the fat cells accumulate triglycerides and expand in size (review figure 5-20, p. 155). -when the cells enlarge, they stim- ulate cell proliferation so that their numbers increase again.5 thus obesity develops when a person s fat cells increase in number, in size, or quite often both. -figure 9- 2 illustrates fat cell development. -when energy out exceeds energy in, the size of fat cells dwindles, but not their number. -people with extra fat cells tend to regain lost weight rapidly; with weight gain, their many fat cells readily fill. -in contrast, people with an average number of enlarged fat cells may be more successful in maintaining weight losses; when their cells shrink, both cell size and number are normal. -prevention of obesity is most critical, then, during the growing years when fat cells increase in number. -as mentioned, excess fat is typically stored in adipose tissue. -this stored fat may be well tolerated, but fat accumulation in organs such as the heart or liver clearly plays a key role in the development of diseases such as heart failure or fatty liver.6 fat cell metabolism the enzyme lipoprotein lipase (lpl) promotes fat storage in both adipose and muscle cells. -obese people generally have much more lpl activity in their fat cells than lean people do (their muscle cell lpl activity is similar, though). -this high lpl activity makes fat storage especially efficient. -consequently, even modest excesses in energy intake have a more dramatic impact on obese people than on lean people. -the activity of lpl is partially regulated by gender-specific hormones estrogen in women and testosterone in men. -in women, fat cells in the breasts, hips, and thighs produce abundant lpl, putting fat away in those body sites; in men, fat cells in the abdomen produce abundant lpl. -this enzyme activity explains why men tend to develop central obesity around the abdomen (apple-shaped) whereas women more readily develop lower-body fat around the hips and thighs (pear- shaped). -gender differences are also apparent in the activity of the enzymes controlling the release and breakdown of fat in various parts of the body. -the release of lower- body fat is less active in women than in men, whereas the release of upper-body fat is similar. -furthermore, the rate of fat breakdown is lower in women than in men. -consequently, women may have a more difficult time losing fat in general, and from the hips and thighs in particular. -enzyme activity may also explain why some people who lose weight regain it so easily. -after weight loss, lpl activity increases, and it does so most dramatically in people who were fattest prior to weight loss. -apparently, weight loss serves as a sig- nal to the gene that produces the lpl enzyme, saying make more of the enzyme that stores fat. -people easily regain weight after having lost it because they are bat- figure 9-2 fat cell development fat cells are capable of increasing their size by 20-fold and their number by several thousandfold. -weight management: overweight, obesity, and underweight 283 during growth, fat cells increase in number. -when energy intake exceeds expenditure, fat cells increase in size. -when fat cells have enlarged and energy intake continues to exceed energy expenditure, fat cells increase in number again. -with fat loss, the size of the fat cells shrinks but not the number. -obesity due to an increase in the number of fat cells is hyperplastic obesity. -obesity due to an increase in the size of fat cells is hypertrophic obesity. -the adverse effects of fat in nonadipose tissues are known as lipotoxicity. -reminder: lipoprotein lipase (lpl) is an enzyme that hydrolyzes triglycerides pass- ing by in the bloodstream and directs their parts into the cells, where they can be metabolized or reassembled for storage. -tling against enzymes that want to store fat. -the activities of these and other pro- teins provide an explanation for the observation that some inner mechanism seems to set a person s weight or body composition at a fixed point; the body will adjust to restore that set point if the person tries to change it. -set-point theory many internal physiological variables, such as blood glucose, blood ph, and body temperature, remain fairly stable under a variety of conditions. -the hypothalamus and other regulatory centers constantly monitor and delicately adjust conditions to maintain homeostasis. -the stability of such complex systems may depend on set- point regulators that maintain variables within specified limits. -researchers have confirmed that after weight gains or losses, the body adjusts its metabolism to restore the original weight. -energy expenditure increases after weight gain and decreases after weight loss. -these changes in energy expenditure differ from those that would be expected based on body composition alone, and they help to explain why it is so difficult for an underweight person to maintain weight gains and an overweight person to maintain weight losses. -in summary fat cells develop by increasing in number and size. -prevention of excess weight gain depends on maintaining a reasonable number of fat cells. -with weight gains or losses, the body adjusts in an attempt to return to its previous status. -causes of overweight and obesity why do people accumulate excess body fat? -the obvious answer is that they take in more food energy than they expend. -but that answer falls short of explaining why they do this. -is it genetic? -environmental? -cultural? -behavioral? -socioeconomic? -psychological? -metabolic? -all of these? -most likely, obesity has many interrelated causes. -why an imbalance between energy intake and energy expenditure occurs remains a bit of a mystery; the next sections summarize possible explanations. -epidemic (ep-ih-dem-ick): the appearance of a disease (usually infectious) or condition that attacks many people at the same time in the same region. -epi = upon demos = people set point: the point at which controls are set (for example, on a thermostat). -the set- point theory that relates to body weight proposes that the body tends to maintain a certain weight by means of its own internal controls. -284 chapter 9 leptin: a protein produced by fat cells under direction of the ob gene that decreases appetite and increases energy expenditure; sometimes called the ob protein. -leptos = thin genetics genetics plays a true causative role in relatively few cases of obesity, for example, in prader-willi syndrome a genetic disorder characterized by excessive appetite, mas- sive obesity, short stature, and often mental retardation. -most cases of obesity, how- ever, do not stem from a genetic mutation, yet genetic influences do seem to be involved. -researchers have found that adopted children tend to be similar in weight to their biological parents, not to their adoptive parents. -studies of twins yield similar findings: identical twins are twice as likely to weigh the same as fraternal twins even when reared apart. -these findings suggest an important role for genetics in determining a person s susceptibility to obesity. -in other words, even if genes do not cause obesity, genetic factors interact with the food intake and activity patterns that lead to it and the metabolic pathways that maintain it.7 clearly, something genetic makes a person more or less likely to gain or lose weight when overeating or undereating.8 some people gain more weight than oth- ers on comparable energy intakes. -given an extra 1000 kcalories a day for 100 days, some pairs of identical twins gain less than 10 pounds while others gain up to 30 pounds. -within each pair, the amounts of weight gained, percentages of body fat, and locations of fat deposits are similar. -similarly, some people lose more weight than others following comparable exercise routines. -researchers have been examining several genes in search of answers to obesity questions. -as the section on protein synthesis in chapter 6 described, each cell ex- presses only the genes for the proteins it needs, and each protein performs a unique function. -the following paragraphs describe some recent research involving pro- teins that might help explain appetite control, energy regulation, and obesity de- velopment.9 leptin researchers have identified an obesity gene, called ob, which is expressed primarily in the adipose tissue and codes for the protein leptin. -leptin acts as a hor- mone, primarily in the hypothalamus. -research suggests that leptin from adipose tissue signals sufficient energy stores and promotes a negative energy balance by suppressing appetite and increasing energy expenditure. -changes in energy expen- diture primarily reflect changes in basal metabolism but may also include changes in physical activity patterns. -leptin is also released from stomach cells in response to the presence of food, suggesting a role for both short-term and long-term satiety regulation.10 mice with a defective ob gene do not produce leptin and can weigh up to three times as much as normal mice and have five times as much body fat (see figure 9- 3). -when injected with a synthetic form of leptin, the mice rapidly lose body fat. -(because leptin is a protein, it would be destroyed during digestion if given orally; consequently, it must be given by injection.) -the fat cells not only lose fat, but they self-destruct (reducing cell number), which may explain why weight gains are de- layed when the mice are fed again. -although extremely rare, a genetic deficiency of leptin has been identified in hu- man beings as well. -an error in the gene that codes for leptin has been discovered in a few extremely obese children with barely detectable blood levels of leptin. -without leptin, the children have little appetite control; they are constantly hungry and eat considerably more than their siblings or peers. -given daily injections of leptin, these children lost a substantial amount of weight, confirming leptin s role in regulating appetite and body weight.11 not too surprisingly, leptin injections are effective in suppressing appetite and supporting weight loss only when overeating and obesity are the result of a leptin deficiency. -very few obese people have a leptin deficiency, however. -in fact, obese people generally have high leptin levels, and weight gain increases leptin concen- trations. -researchers speculate that in obesity, leptin rises in an effort to overcome an insensitivity or resistance to leptin. -weight management: overweight, obesity, and underweight 285 figure 9-3 mice with and without leptin compared both of these mice have a defective ob gene. -consequently, they do not produce lep- tin. -they both became obese, but the one on the right received daily injections of leptin, which suppressed food intake and increased energy expenditure, resulting in weight loss. -. -c n i , n e g m a y s e t r u o c without leptin, this mouse weighs almost three times as much as a normal mouse. -with leptin treatment, this mouse lost a significant amount of weight but still weighs almost one and a half times as much as a normal mouse. -some researchers have reexamined the evidence on leptin from another point of view one of undernutrition. -instead of focusing on leptin s role as a satiety signal that might help prevent obesity by regulating food intake, they view leptin as a starvation hormone that signals energy deficits.12 when energy intake is low, lep- tin levels decline, and metabolism slows in an effort to reduce energy demands. -clearly, leptin plays a major role in energy regulation, but additional research is needed to clarify its actions when intake is either excessive or deficient. -in addition to its involvement in energy regulation, leptin plays several other roles in the body.13 for example, leptin may inform the female reproductive system about body fat reserves; stimulate growth of new blood vessels, especially in the cornea of the eye; enhance the maturation of bone marrow cells; promote forma- tion of red blood cells; and help support a normal immune response.14 elevated lep- tin levels may be partially responsible for the early maturation that commonly occurs in obese children.15 ghrelin leptin interacts with another protein that also acts as a hormone primar- ily in the hypothalamus.16 known as ghrelin, this protein is secreted primarily by the stomach cells and promotes a positive energy balance by stimulating appetite and promoting efficient energy storage.17 the role ghrelin plays in regulating food intake and body weight is currently the subject of much intense research.18 ghrelin triggers the desire to eat. -blood levels of ghrelin typically rise before and fall after a meal in proportion to the kcalories ingested reflecting the hunger and satiety that precede and follow eating.19 in general, fasting blood levels correlate inversely with body weight: lean people have high ghrelin levels and obese people have low levels.20 interestingly, although ghrelin levels are high in underweight people, they are exceptionally high in anorexia nervosa and return to normal with nutrition intervention indicating that both body weight and nutrition status in- fluence ghrelin levels.21 also noteworthy, ghrelin levels in prader-willi syndrome are markedly high and remain elevated even after a meal, which helps to explain the excessive appetite commonly seen in this disorder.22 similarly, ghrelin levels do not seem to decline as much after a meal in obese people or in people with binge- eating disorders as they do for lean people.23 ghrelin fights to maintain a stable body weight.24 in fact, some researchers spec- ulate that its role is to maximize fat stores during times of famine.25 on average, ghrelin levels are high whenever the body is in negative energy balance, as occurs during low-kcalorie diets, for example. -this response may help explain why weight ghrelin (grell-in): a protein produced by the stomach cells that enhances appetite and decreases energy expenditure. -ghre = growth 286 chapter 9 reminder: in coupled reactions, the energy released from the breakdown of one com- pound is used to create a bond in the for- mation of another compound. -in uncoupled reactions, the energy is released as heat. -brown adipose tissue: masses of specialized fat cells packed with pigmented mitochondria that produce heat instead of atp. -gene pool: all the genetic information of a population at a given time. -loss is so difficult to maintain. -weight loss is more successful following gastric by- pass surgery, in part because ghrelin levels are abnormally low. -(why this is so re- mains unknown. -)26 ghrelin levels decline again whenever the body is in positive energy balance, as occurs with weight gains.27 ghrelin levels also decline in response to high levels of pyy, a peptide that the gi cells secrete after a meal in proportion to the kcalories ingested.28 in one study, peo- ple who were given pyy and then offered buffet meals consumed 30 percent fewer kcalories in the day than the control group.29 like the hormone leptin, pyy signals satiety and decreases food intake, but unlike leptin, pyy may be an effective treat- ment for obesity. -an ideal diet would maintain the satiating hormones (leptin, pyy, and cholecystokinin) and minimize the appetite stimulating hormone (ghrelin).30 fortunately, the diet that seems to do that best is one that is low in fat and rich in fiber. -like leptin, ghrelin plays roles in the body beyond energy regulation. -in fact, it was first recognized for its participation in growth hormone activity.31 some re- search also indicates that ghrelin promotes sleep.32 interestingly, a lack of sleep increases the hunger hormone ghrelin and decreases the satiety hormone leptin which may help to explain epidemiological evidence finding an association be- tween short sleep duration and high bmi.33 researchers are trying to understand the relationships among genes, sleep disorders, eating habits, and other related factors that may influence body weight and weight gain.34 uncoupling proteins other genes code for proteins involved in energy metabo- lism. -these proteins may influence the storing or expending of energy with different efficiencies or in different types of fat. -the body has two types of fat: white and brown adipose tissue.35 white adipose tissue stores fat for other cells to use for en- ergy; brown adipose tissue releases stored energy as heat. -recall from chapter 7 that when fat is oxidized, some of the energy is released in heat and some is captured in atp. -in brown adipose tissue, oxidation may be uncoupled from atp formation, producing heat only.36 by radiating energy away as heat, the body expends, rather than stores, energy. -brown fat and heat production is particularly important in new- borns and in animals exposed to cold weather, especially those that hibernate.37 they have plenty of brown adipose tissue. -in contrast, most human adults have lit- tle brown fat less than 1 percent of all fat cells and interspersed among the white fat cells.38 the role of brown fat in body weight regulation, though probably mini- mal, is not yet understood.39 uncoupling proteins are active not only in brown fat, but also in white fat and many other tissues. -their actions seem to influence the basal metabolic rate (bmr) and oppose the development of obesity. -animals with abundant amounts of these uncoupling proteins resist weight gain, whereas those with minimal amounts gain weight easily. -similarly, people with a genetic variant of an uncoupling protein have lower metabolic rates and are more overweight than others.40 whether the body dissipates the energy from an ice cream sundae as heat or stores it in body fat has major consequences for a person s body weight. -environment although genetic studies indicate that body weight may be at least partially herita- ble, they do not fully explain obesity. -in contrast to the studies mentioned earlier that found similar weights between identical twins, some identical twins have dra- matically different body weights. -with obesity rates rising over the past three decades and the gene pool remaining relatively unchanged, environment must also play a role in obesity. -the environment includes all of the circumstances that we encounter daily that push us toward fatness or thinness. -keep in mind that genetic and environmental factors are not mutually exclusive; genes can influence eating behaviors, for example, and numerous eating behaviors influence body weight. -a simple behavior, such as regularly skipping breakfast, for example, can contribute to obesity.41 weight management: overweight, obesity, and underweight 287 overeating one explanation for obesity is that overweight people overeat, al- though diet histories may not always reflect high intakes. -diet histories are not al- ways accurate records of actual intakes; both normal-weight and obese people commonly misreport their dietary intakes.42 most importantly, current dietary in- takes may not reflect the eating habits that led to obesity. -obese people who had a positive energy-balance for years and accumulated excess body fat may not cur- rently have a positive energy balance. -this reality highlights an important point: the energy-balance equation must consider time. -both present and past eating and activity patterns influence current body weight. -we live in an environment that exposes us to an abundance of high-kcalorie, high-fat foods that are readily available, relatively inexpensive, heavily advertised, and reasonably tasty.43 food is available everywhere, all the time thanks largely to fast food. -our highways are lined with fast-food restaurants, and conven- ience stores and service stations offer fast food as well. -fast food is available in our schools, malls, and airports. -it s convenient and it s available morning, noon, and night and all times in between. -most alarming are the extraordinarily large serving sizes and ready-to-go meals that offer supersize combinations. -people buy the large sizes and combinations, perceiving them to be a good value, but then they eat more than they need a bad deal. -large package or portion sizes can increase consumption even when the food is not particularly appealing. -moviegoers given stale popcorn ate more when eating from a huge container than from a large container (both sizes were greater than anyone could finish).44 simply put, large portion sizes deliver more kcalo- ries.45 and portion sizes of virtually all foods and beverages have increased markedly in the past several decades, most notably at fast-food restaurants.46 not only have portion sizes increased over time, but they are now two to eight times larger than standard serving sizes.47 the trend toward large portion sizes parallels the increasing prevalence of overweight and obesity in the united states, beginning in the 1970s, increasing sharply in the 1980s, and continuing today.48 restaurant food, especially fast food, is a major player in the development of obesity.49 fast food is often high in fat.50 fat s 9 kcalories per gram quickly add up, amplifying people s energy intakes and enlarging their body fat stores. -the combi- nation of large portions and energy-dense foods is a double whammy.51 reducing portion sizes is somewhat helpful, but the real kcalorie savings come from lowering the energy density.52 after all, large portions of foods with low energy density such as lean meats, fruits, and vegetables can help with weight loss. -unfortunately, these foods may not be as inexpensive, flavorful, and convenient as energy dense foods.53 restaurants can help their customers eat healthfully by reducing portion sizes and offering more fruits, vegetables, legumes, and whole grains.54 physical inactivity our environment fosters physical inactivity as well.55 life re- quires little exertion escalators carry us up stairs, automobiles take us across town, buttons roll down windows, and remote controls change television channels from a distance. -modern technology has replaced physical activity at home, at work, and in transportation. -inactivity contributes to weight gain and poor health.56 in turn, watching television, playing video games, and using the computer may contribute most to physical inactivity. -the more time people spend in these sedentary activities, the more likely they are to be overweight.57 these sedentary activities contribute to weight gain in several ways. -first, they require little energy beyond the resting metabolic rate. -second, they replace time spent in more vigorous activities. -third, watching television influences food pur- chases and correlates with between-meal snacking on the high-kcalorie, high-fat foods most heavily advertised. -people may be obese, therefore, not because they eat too much, but because they move too little both in purposeful exercise and in the routines of daily life. -one study reports that the differences in the time obese and lean people spent lying, sit- ting, standing, and moving accounts for about 350 kcalories a day.58 some obese people are so extraordinarily inactive that even when they eat less than lean people, the food industry spends $30 billion a year on advertising. -the message? -eat more. -want fries with that? -a supersize portion delivers over 600 kcalories. -s e g a m i r e t i p u j / e t y b k c o t s lack of physical activity fosters obesity. -288 chapter 9 dri for physical activity: 60 min/day (moderate intensity) bmi 25.0-29.9 = overweight bmi (cid:3)30 = obese men: (cid:4)40 in ((cid:4)102 cm) women: (cid:4)35 in ((cid:4)88 cm) for reference, a woman with a bmi of 26 might be: 5 ft 3 in, 146 lb (1.60 m, 66.2 kg) 5 ft 5 in, 156 lb (1.65 m, 70.8 kg) 5 ft 7 in, 166 lb (1.70 m, 75.3 kg) obese people and overweight people with two or more of these risk factors require aggressive treatment: hypertension cigarette smoking high ldl low hdl impaired glucose tolerance family history of heart disease men (cid:3)45 yr; women (cid:3)55 yr for reference, a man with a bmi of 28 might be: 5 ft 8 in, 184 lb (1.73 m, 83.5 kg) 5 ft 10 in, 195 lb (1.78m, 88.5 kg) 6 ft, 206 lb (1.83 m, 93.4 kg) they still have an energy surplus. -reducing their food intake further would jeopard- ize health and incur nutrient deficiencies. -physical activity is a necessary compo- nent of nutritional health. -people must be physically active if they are to eat enough food to deliver all the nutrients they need without unhealthy weight gain. -in fact, to prevent weight gain, the dri suggests an accumulation of 60 minutes of moderately intense physical activities every day in addition to the less intense activities of daily living. -in summary obesity has many causes and different combinations of causes in different people. -some causes, such as overeating and physical inactivity, may be within a person s control, and some, such as genetics, may be beyond it. -problems of overweight and obesity an estimated 35 to 45 percent of all u.s. women (and 20 to 30 percent of u.s. men) are trying to lose weight at any given time, spending up to $40 billion each year to do so.59 some of these people do not even need to lose weight. -others may benefit from weight loss, but they are not successful. -relatively few people succeed in losing weight, and even fewer succeed permanently. -whether an overweight person needs to lose weight is a question of health. -health risks chapter 8 described some of the health problems that commonly accompany obe- sity. -in evaluating the risks to health from obesity, health care professionals use three indicators:60 body mass index (bmi, as described in chapter 8) waist circumference (also described in chapter 8) disease risk profile, taking into account family history, life-threatening dis- eases, and common risk factors for chronic diseases61 the higher the bmi, the greater the waist circumference and the more risk factors the greater the urgency to treat obesity. -people can best decide whether weight loss might be beneficial by considering their health status and motivation. -people who are overweight by bmi standards, but otherwise in good health, might not benefit from losing weight; they might fo- cus on preventing further weight gains instead. -in contrast, those who are obese and suffering from a life-threatening disease such as diabetes might improve their health substantially by adopting a diet and exercise plan that supports weight loss. -motivation is a key component; to lose weight, a person needs to be ready and willing to make lifestyle changes for a lifetime. -overweight in good health often a person s motivations for weight loss have nothing to do with health. -a healthy young woman with a bmi of 26 might want to lose a few pounds for spring break, but doing so might not improve her health. -in fact, if she opts for a starvation diet or diet pills, she would be healthier not trying to lose weight. -obese or overweight with risk factors weight loss is recommended for peo- ple who are obese and those who are overweight (or who have a high waist circum- ference) with two or more risk factors for chronic diseases. -a 50-year-old man with a bmi of 28 who has high blood pressure and a family history of heart disease can weight management: overweight, obesity, and underweight 289 improve his health by adopting a diet low in saturated fat and a regular exercise plan. -obese or overweight with life threatening condition weight loss is also recommended for a person who is either overweight or obese and suffering from a life-threatening condition such as heart disease, diabetes, or sleep apnea. -the health benefits of weight loss are clear. -for example, a 30-year-old man with a bmi of 40 might be able to prevent or control the diabetes that runs in his family by losing 75 pounds. -although the effort required to do so may be great, it may be no greater than the effort and consequences of living with diabetes. -perceptions and prejudices many people assume that every obese person can achieve slenderness and should pursue that goal. -first consider that most obese people do not for whatever rea- son successfully lose weight and maintain their losses. -then consider the preju- dice involved in that assumption. -people come with varying weight tendencies, just as they come with varying potentials for height and degrees of health, yet we do not expect tall people to shrink or healthy people to get sick in an effort to be- come normal. -social consequences large segments of our society place such enormous value on thinness that obese people face prejudice and discrimination on the job, at school, and in social situations: they are judged on their appearance more than on their character.62 socially, obese people are stereotyped as lazy and lacking in self- control. -such a critical view of overweight is not prevalent in many other cultures, including segments of our own society. -instead, overweight is simply accepted or even embraced as a sign of robust health and beauty. -many overweight people to- day are tired of the obsession with weight control and simply want to be accepted as they are. -to free society of its obsession with body weight and prejudice against obe- sity, people must first learn to judge others for who they are and not for what they weigh. -psychological problems psychologically, obese people may suffer embarrass- ment when others treat them with hostility and contempt, and some have even come to view their own bodies as grotesque and loathsome. -parents and friends may scold them for lacking the discipline to resolve their weight problems. -health care professionals, including dietitians, are among the chief offenders. -criticism from others hurts self-esteem. -feelings of rejection, shame, or depression are common among obese people. -most weight-loss programs assume that the problem can be solved simply by ap- plying willpower and hard work. -if determination were the only factor involved, though, the success rate would be far greater than it is. -overweight people may readily assume blame for failure to lose weight and maintain the losses when, in fact, it is the programs that have failed. -ineffective treatment and its associated sense of failure add to a person s psychological burden. -figure 9-4 illustrates how the devastating psychological effects of obesity and dieting perpetuate themselves. -dangerous interventions people attach so many dreams of happiness to weight loss that they willingly risk huge sums of money for the slightest chance of success. -as a result, weight-loss schemes flourish. -of the tens of thousands of claims, treatments, and theories for losing weight, few are effective and many are downright dangerous. -the negative effects must be carefully considered before embarking on any weight-loss program. -some interventions entail greater dangers than the risk of being overweight. -phys- ical problems may arise from fad diets, yo-yo dieting, and drug use, and psycho- logical problems may emerge from repeated failures. -obese people and overweight people with any of these diseases require aggressive treatment: heart disease diabetes (type 2) sleep apnea (a disturbance of breathing during sleep, including temporarily stopping) for reference, a man with a bmi of 40 might be: 5 ft 8 in, 265 lb (1.73 m, 120.2 kg) 5 ft 10 in, 280 lb (1.78 m, 127 kg) 6 ft, 295 lb (1.83 m, 133.8 kg) figure 9-4 of weight cycling the psychology i am fat and unhappy. -i lose a little weight, but then regain it (and sometimes more). -i try too hard to reach an unrealistic goal. -i want to be happy. -if i lose weight, i will be happy. -scrutinize fad diets, magic potions, and wonder gizmos with a healthy dose of skepticism. -290 chapter 9 so many promises, so little success. -ephedrine is an amphetamine-like sub- stance extracted from the chinese ephedra herb ma huang. -fad diets: popular eating plans that promise quick weight loss. -most fad diets severely limit certain foods or overemphasize others (for example, never eat potatoes or pasta or eat cabbage soup daily). -serotonin (ser-oh-tone-in): a neurotransmitter important in sleep regulation, appetite control, and sensory perception, among other roles. -serotonin is synthesized in the body from the amino acid tryptophan with the help of vitamin b6. -table 9-1 weight-loss consumer bill of rights (an example) 1. warning: rapid weight loss may cause serious health problems. -rapid weight loss is weight loss of more than 11 2 to 2 pounds per week or weight loss of more than 1 percent of body weight per week after the second week of participation in a weight-loss program. -2. consult your personal physician before starting any weight-loss program. -3. only permanent lifestyle changes, such as making healthful food choices and increasing physi- cal activity, promote long-term weight loss and successful maintenance. -4. qualifications of this provider are available upon request. -5. you have a right to: ask questions about the potential health risks of this program and its nutritional content, psychological support, and educational components. -receive an itemized statement of the actual or estimated price of the weight-loss program, including extra products, services, supplements, examinations, and laboratory tests. -know the actual or estimated duration of the program. -know the name, address, and qualifications of the dietitian or nutritionist who has reviewed and approved the weight-loss program. -t i d e o t o h p / n o r a l l i b some of the nation s most popular diet books and weight-loss programs have mis- led consumers with unsubstantiated claims and deceptive testimonials. -furthermore, they fail to provide an assessment of the short- and long-term results of their treat- ment plans, even though such evaluations are possible and would permit consumers to make informed decisions. -of course, some weight-loss programs are better than others in terms of cost, approach, and customer satisfaction, but few are particularly successful in helping people keep lost weight off. -clients can expect reputable pro- grams to abide by a consumer bill of rights that explains the risks associated with weight-loss programs and provides honest predictions of success (see table 9-1). -fad diets fad diets often sound good, but they typically fall short of delivering on their promises. -they espouse exaggerated or false theories of weight loss and ad- vise consumers to follow inadequate diets. -some fad diets are hazardous to health as highlight 9 explains. -adverse reactions can be as minor as headaches, nausea, and dizziness or as serious as death. -table h9-4 (on p. 320) offers guidelines for identify- ing unsound weight-loss schemes and fad diets. -weight-loss products millions of people in the united states use nonprescription weight-loss products. -most of them are women, especially young overweight women, but almost 10 percent are of normal weight. -in their search for weight-loss magic, some consumers turn to natural herbal products and dietary supplements, even though few have proved to be effective. -st. john s wort, for example, contains substances that inhibit the uptake of serotonin and thus suppress appetite. -in addition to the many cautions that accompany the use of all herbal remedies, consumers should be aware that st. john s wort is often prepared in combination with the herbal stimulant ephedrine. -ephedrine- containing supplements promote modest short-term weight loss (about 2 pounds a month), but the associated risks are high.63 these supplements have been impli- cated in several cases of heart attacks and seizures and have been linked to about 100 deaths. -for this reason, the fda has banned the sale of dietary supplements containing ephedra, but they are readily available on the internet. -* table 9-2 pres- ents the claims and the dangers behind ephedrine and several other common di- etary supplements used for weight loss.64 herbal laxatives containing senna, aloe, rhubarb root, cascara, castor oil, and buckthorn (or various combinations) are commonly sold as dieter s tea. -such concoctions commonly cause nausea, vomiting, diarrhea, cramping, and fainting and may have contributed to the deaths of four women who had drastically re- duced their food intakes. -consumers mistakenly believe that laxatives will dimin- ish nutrient absorption and reduce kcalorie intake, but remember that absorption * ma huang (ephedrine) is illegal in canada. -weight management: overweight, obesity, and underweight 291 table 9-2 selected herbal and other dietary supplements marketed for weight loss product bitter orangea (citrus aurantium, a natural flavoring that contains synephrine, a compound structurally similiar to epinephrine) chitosan b (pronounced kite-oh-san; derived from chitin, the substance that forms the hard shells of lobsters, crabs, and other crustaceans) manufacturers claims stimulates weight loss; provides an alternative to ephedra binds to dietary fat, preventing digestion and absorption research findings adverse effects little evidence available may increase blood pressure; may interact with drugs ineffective impaired absorption of fat-soluble vitamins chromium (trace mineral) eliminates body fat ineffective; weight gain reported when not accompanied by exercise headaches, sleep disturbances, and mood swings; hexavalent form is toxic and carcinogenic conjugated linoleic acid (cla; a group of fatty acids related to linoleic acid, but with different cis- and trans-configurations) reduces body fat and suppresses appetite some evidence in animal studies, but ineffective in human studies none known ephedrine c (amphetamine-like substance derived from the chinese ephedra herb ma huang) speeds body s metabolism short-term weight loss and dangerous side effects insomnia, tremors, heart attacks, strokes, and death; fda has banned the sale of these products hydroxycitric acid d (active ingredient derived from the rind of the tropical fruit garcinia cambogia) inhibits the enzyme that converts citric acid to fat; suppresses appetite ineffective toxicity symptoms reported in animal studies; headaches, respiratory and gastrointestinal dis- tress in humans pyruvate e (3-carbon compound produced during glycolysis) speeds body s metabolism modest weight loss with high doses gi distress yohimbine (derived from the bark of a west african tree) promotes weight loss ineffective nervousness, insomnia, anxiety, dizziness, tremors, headaches, nausea, vomiting, hypertension note: the fda has not approved the use of any of these products; most products are used in conjunction with a 1000- to 1800-kcalorie diet. -a marketed under the trade names xenadrine efx, metabolife ultra, now diet support. -b marketed under the trade names chitorich, exofat, fat breaker, fat blocker, fat magnet, fat trapper, and fatsorb. -c marketed under the trade names diet fuel, metabolife, and nature s nutrition formula one. -d marketed under the trade names ultra burn, citralean, citrimax, citrin, slim life, brindleslim, medislim, and beer belly busters. -e marketed under the trade names exercise in a bottle, pyruvate punch, pyruvate-c, and provate. -occurs primarily in the small intestine and these laxatives act on the large intestine. -highlight 18 explores the possible benefits and potential dangers of herbal products and other alternative therapies. -as it explains, current laws do not require manufac- turers of dietary supplements to test the safety or effectiveness of any product. -con- sumers cannot assume that an herb or supplement of any kind is safe or effective just because it is available on the market. -supplements may contain contaminants and may not contain the amounts of active ingredients listed on the labels.65 any- one using dietary supplements for weight loss should first consult with a physician. -other gimmicks other gimmicks don t help with weight loss either. -hot baths do not speed up metabolism so that pounds can be lost in hours. -steam and sauna baths do not melt the fat off the body, although they may dehydrate people so that they lose wa- ter weight. -brushes, sponges, wraps, creams, and massages intended to move, burn, or break up cellulite do nothing of the kind because there is no such thing as cellulite. -in summary the question of whether a person should lose weight depends on many fac- tors: among them are the extent of overweight, age, health, and genetic makeup. -not all obesity will cause disease or shorten life expectancy. -just as there are unhealthy, normal-weight people, there are healthy, obese people. -some people may risk more in the process of losing weight than in remaining overweight. -fad diets and weight-loss supplements can be physically and psy- chologically damaging. -cellulite (sell-you-light or sell-you-leet): supposedly, a lumpy form of fat; actually, a fraud. -fatty areas of the body may appear lumpy when the strands of connective tissue that attach the skin to underlying muscles pull tight where the fat is thick. -the fat itself is the same as fat anywhere else in the body. -if the fat in these areas is lost, the lumpy appearance disappears. -292 chapter 9 the field of medicine that specializes in treating obesity is called bariatrics. -bar = weight surgery may be an option for people with all of the following conditions: have tried diet and exercise programs without success remain obese (bmi (cid:4) 35) have weight-related health problems clinically severe obesity: a bmi of 40 or greater or a bmi of 35 or greater with additional medical problems. -a less preferred term used to describe the same condition is morbid obesity. -sibutramine (sigh-byoo-tra-mean): a drug used in the treatment of obesity that slows the reabsorption of serotonin in the brain, thus suppressing appetite and creating a feeling of fullness. -orlistat (or-leh-stat): a drug used in the treatment of obesity that inhibits the absorption of fat in the gi tract, thus limiting kcaloric intake. -aggressive treatments for obesity the appropriate strategies for weight reduction depend on the degree of obesity and the risk of disease. -an overweight person in good health may need only to improve eating habits and increase physical activity, but someone with clinically severe obesity may need more aggressive treatment options drugs or surgery.66 drugs appear to be modestly effective and safe, at least in the short term; surgery appears to be dramatically effective but can have severe complications, at least for some peo- ple.67 drugs based on new understandings of obesity s genetic basis and its classification as a chronic disease, much research effort has focused on drug treatments for obesity. -ex- perts reason that if obesity is a chronic disease, it should be treated as such and the treatment of most chronic diseases includes drugs. -the challenge, then, is to develop an effective drug that can be used over time without adverse side effects or the po- tential for abuse. -several drugs for weight loss have been tried over the years. -when used as part of a long-term, comprehensive weight-loss program, drugs can help obese people to lose weight. -because weight regain commonly occurs with the discontinuation of drug therapy, treatment must be long term. -yet the long-term use of drugs poses risks. -we don t yet know whether a person would be harmed more from maintaining a 100- pound excess or from taking a drug for a decade to keep the 100 pounds off. -physicians must prescribe drugs appropriately, inform consumers of the potential risks, and mon- itor side effects carefully. -two prescription drugs are currently on the market: sibu- tramine and orlistat. -one reduces food intake; the other reduces nutrient absorption.68 sibutramine sibutramine suppresses appetite. -* the drug is most effective when used in combination with a reduced-kcalorie diet and increased physical activity. -side effects include dry mouth, headache, constipation, rapid heart rate, and high blood pressure. -the fda warns those with high blood pressure not to use sibu- tramine and advises others to monitor their blood pressure. -orlistat orlistat takes a different approach to weight control. -** it inhibits pancreatic lipase activity in the gi tract, thus blocking dietary fat digestion and absorption by about 30 percent. -the drug is taken with meals and is most effective when accompa- nied by a reduced-kcalorie, low-fat diet. -side effects include gas, frequent bowel move- ments, and reduced absorption of fat-soluble vitamins. -the fda is recently approved the over-the-counter sale of a low-dose version of orlistat. -other drugs some physicians prescribe drugs that have not been approved for weight loss, a practice known as off-label use. -these drugs have been approved for other conditions (such as seizures) and incidentally cause modest weight loss.69 physicians using off-label drugs must be well-informed of the drugs use and effects and monitor their patients responses closely. -surgery surgery as an approach to weight loss is justified in some specific cases of clinically severe obesity. -over 100,000 such surgeries are performed annually.70 as figure 9-5 shows, surgical procedures effectively limit food intake by reducing the capacity of the stomach. -in addition, they suppress hunger by reducing production of the hor- mone ghrelin.71 the results are dramatic: most people achieve a lasting weight loss of more than 50 percent of their excess body weight.72 importantly, most of them ex- perience dramatic improvements in their diabetes, blood lipids, and blood pressure.73 * sibutramine is marketed under the trade name meridia. -** orlistat is marketed under the trade name xenical. -the low-dose, over-the-counter version of orlistat is marketed under the trade name alli (al-eye). -weight management: overweight, obesity, and underweight 293 figure 9-5 gastric surgery used in the treatment of severe obesity both of these surgical procedures limit the amount of food that can be comfort- ably eaten. -esophagus small stomach pouch stomach duodenum jejunum large intestine surgical staples esophagus gastric band stomach port in gastric bypass, the surgeon constructs a small stomach pouch and creates an outlet directly to the small intestine, bypassing most of the stomach, the entire duodenum, and some of the jejunum. -(dark areas highlight the flow of food through the gi tract; pale areas indicate bypassed sections.) -in gastric banding, the surgeon uses a gastric band to reduce the opening from the esophagus to the stomach. -the size of the opening can be adjusted by inflating or deflating the band by way of a port placed in the abdomen just beneath the skin. -whether surgery is a reasonable option for obese teens is the subject of much de- bate among pediatricians and bariatric surgeons.74 in addition to the criteria listed in the margin (p. 292) for adults considering surgery, teens must have a bmi greater than 40, and they must have attained skeletal maturity.75 considerations of the adolescent s physical growth, emotional development, family support, and ability to comply with dietary instructions weigh heavily in the decision. -the long-term safety and effectiveness of gastric surgery depend, in large part, on compliance with dietary instructions. -common immediate postsurgical compli- cations include infections, nausea, vomiting, and dehydration. -in the long term, deficiencies of iron, vitamin b12, folate, calcium, and vitamin d are common.76 weight regain and psychological problems may also occur. -lifelong medical super- vision is necessary for those who choose the surgical route, but in suitable candi- dates, the health benefits of weight loss may prove worth the risks.77 another surgical procedure is used, not to treat obesity, but to remove the evi- dence. -plastic surgeons can extract some fat deposits by suction lipectomy, or lipo- suction. -this cosmetic procedure has little effect on body weight, but can alter body shape slightly in specific areas. -liposuction is a popular procedure in part be- cause of its perceived safety, but, in fact, serious complications can occasionally re- sult in death. -furthermore, removing adipose tissue by way of liposuction does not provide the health benefits that typically accompany weight loss.78 in summary obese people with high risks of medical problems may need aggressive treat- ment, including drugs or surgery. -others may benefit most from improving eating and exercise habits. -294 chapter 9 weight-loss strategies successful weight-loss strategies embrace small changes, moderate losses, and rea- sonable goals.79 people who lose 10 to 20 pounds in a year by consistently choosing nutrient-dense foods and engaging in regular physical activity are much more likely to maintain the loss and reap health benefits than if they were to lose more weight in less time by adopting a radical fad diet. -in keeping with this philosophy, the 2005 dietary guidelines advise those who need to lose weight to aim for a slow, steady weight loss by decreasing kcalorie intake while maintaining an adequate nutrient intake and increasing physical activity. -even modest weight loss brings health benefits. -modest weight loss, even when a person is still overweight, can improve control of diabetes and reduce the risks of heart disease by lowering blood pressure and blood cholesterol, especially for those with central obesity. -improvements in physical capa- bilities and bodily pain become evident with even a 5-pound weight loss. -for these reasons, parameters such as blood pressure, blood cholesterol, or even vitality are more useful than body weight in marking success. -people less concerned with disease risks may prefer to set goals for personal fitness, such as being able to play with chil- dren or climb stairs without becoming short of breath. -importantly, they can enjoy living a healthy life instead of focusing on the elusive goal of losing weight. -whether the goal is health or fitness, expectations need to be reasonable. -un- reachable targets ensure frustration and failure. -when goals are achieved or ex- ceeded, people enjoy rewards instead of finding disappointment. -research findings highlight the great disparity between lofty expectations and reasonable success.80 before beginning a weight-loss program, obese women iden- tified the weights they would describe as dream, happy, acceptable, and dis- appointing (see figure 9-6). -all of these weights were below their starting weight. -their goal weights far exceeded the 5 to 10 percent recommended by experts, or even the 15 percent reported by the most successful weight-loss studies. -even their disappointing weights exceeded recommended goals. -close to a year later, and after an average loss of 35 pounds, almost half of the women did not achieve even their disappointing weights. -they did, however, experience more physical, social, and psychological benefits than they had predicted for that weight. -still, in a cul- figure 9-6 reasonable weight goals and expectations compared ) s d n u o p ( t i h g e w 220 200 180 160 140 120 100 0 a reasonable goal weight (10% below initial weight by 6 months and maintained for 1 year) actual weight disappointing weight acceptable weight happy weight dream weight suggested healthy weight range time (year) 1 areasonable goal weights reflect pounds lost over time. -given more time, reasonable goals may eventually fall within the suggested healthy-weight range. -source: adapted from g. d. foster and coauthors, what is a reasonable weight loss? -patients expectations and evaluations of obesity treatment outcomes, journal of consulting and clinical psychology 65 (1997): 79 85. weight management: overweight, obesity, and underweight 295 safe rate for weight loss: 1/2 to 2 lb/week (0.2 to 0.9 kg) 10% body weight/6 mo for a person weighing 110 kg, a 10% loss is 11 kg, or about 0.5 kg a week for six months ture that overvalues thinness, these women were not satisfied with a 16 percent re- duction in weight not because their efforts were unsuccessful, but because their expectations were unrealistic. -depending on initial body weight, a reasonable rate of weight loss for over- weight people is 1/2 to 2 pounds a week, or 10 percent of body weight over six months.81 for a person weighing 250 pounds, a 10 percent loss is 25 pounds, or about 1 pound a week for six months. -such gradual weight losses are more likely to be maintained than rapid losses. -keep in mind that pursuing good health is a lifelong journey. -most adults are keenly aware of their body weights and shapes and realize that what they eat and what they do can make a difference to some ex- tent. -those who are most successful at weight management seem to have fully in- corporated healthful eating and physical activity into their daily lives.82 such advice to reduce energy intake and increase physical activity would hardly sur- prise anyone, yet relatively few people trying to control their weight follow these recommendations. -eating plans contrary to the claims of fad diets, no single food plan is magical, and no specific food must be included or avoided in a weight-management program. -in designing a plan, people need only consider foods that they like or can learn to like, that are available, and that are within their means. -be realistic about energy intake the main characteristic of a weight-loss diet is that it provides less energy than the person needs to maintain present body weight. -if food energy is restricted too severely, dieters may not receive sufficient nu- trients and may lose lean tissue. -rapid weight loss usually means excessive loss of lean tissue, a lower bmr, and a rapid weight gain to follow. -in addition, restrictive eating may set in motion the unhealthy behaviors of eating disorders as previously described in highlight 8. table 9-3 outlines the recommendations of a weight-loss diet. -energy intake should provide nutritional adequacy without excess that is, somewhere between table 9-3 recommendations for a weight-loss diet nutrient kcalories recommended intake for people with bmi 35 approximately 500 to 1000 kcalories per day reduction from for people with bmi between 27 and 35 total fat saturated fatty acidsa monounsaturated fatty acids polyunsaturated fatty acids cholesterola proteinb carbohydratec sodium chloride calcium fiberc usual intake approximately 300 to 500 kcalories per day reduction from usual intake 30% or less of total kcalories 8 to 10% of total kcalories up to 15% of total kcalories up to 10% of total kcalories 300 mg or less per day approximately 15% of total kcalories 55% or more of total kcalories no more than 2400 mg of sodium or approximately 6 g of sodium chloride (salt) per day 1000 to 1500 mg per day 20 to 30 g per day apeople with high blood cholesterol should aim for less than 7 percent kcalories from saturated fat and 200 milligrams of cholesterol per day. -bprotein should be derived from plant sources and lean sources of animal protein. -ccarbohydrates and fiber should be derived from vegetables, fruits, and whole grains. -source: national institutes of health obesity education initiative, the practical guide: identification, evaluation, and treat- ment of overweight and obesity in adults (washington, d.c.: u.s. department of health and human services, 2000), p. 27. -296 chapter 9 deprivation and complete freedom to eat whatever, whenever. -a reasonable sug- gestion is that an adult needs to increase activity and reduce food intake enough to create a deficit of 500 kcalories per day. -such a deficit produces a weight loss of about 1 pound per week a rate that supports the loss of fat efficiently while retain- ing lean tissue. -in general, weight-loss diets provide 1000 to 1200 kcalories per day for women and 1200 to 1600 kcalories a day for men.83 table 9-4 specifies the amounts of foods from each food group for these kcalorie levels. -emphasize nutritional adequacy nutritional adequacy is difficult to achieve on fewer than 1200 kcalories a day, and most healthy adults need never consume any less. -a plan that provides an adequate intake supports a healthier and more successful weight loss than a restrictive plan that creates feelings of starvation and deprivation, which can lead to an irresistible urge to binge. -table 9-4 includes the recommended amounts for diets providing 1000 to 1600 kcalories. -such an intake would allow most people to lose weight and still meet their nutrient needs with careful, nutrient-dense food selections. -(women might need iron supplements.) -keep in mind, too, that well-balanced diets that emphasize fruits, veg- etables, whole grains, lean meats or meat alternates, and low-fat milk products offer many health rewards even when they don t result in weight loss. -a supplement pro- viding vitamins and minerals at or below 100 percent of the daily values can help people following low-kcalorie diets to achieve nutrient adequacy.84 eat small portions as mentioned earlier, portion sizes at markets, at restaurants, and even at home have increased dramatically over the years.85 we have come to ex- pect large portions, and we have learned to clean our plates. -many of us pay more at- tention to these external cues defining how much to eat than to our internal cues of hunger and satiety.86 for health s sake, we may need to learn to eat less food at each meal one piece of chicken for dinner instead of two, a teaspoon of butter on vegeta- bles instead of a tablespoon, and one cookie for dessert instead of six. -the goal is to eat enough food for adequate energy, abundant vitamins and minerals, and some plea- sure, but not more. -this amount should leave a person feeling satisfied not stuffed. -keep in mind that even fat-free and low-fat foods can deliver a lot of kcalories when a person eats large quantities. -a low-fat cookie or two can be a sweet treat even on a weight-loss diet, but larger portions defeat the savings. -lower energy density most people take their cues about how much to eat based on portion sizes, and the larger the portion size, the more they eat even when the food is not particularly tasty.87 to lower energy intake, a person can either reduce the portion size or reduce the energy density.88 selecting low-energy-dense foods seems to be more a successful strategy than restricting portion sizes.89 figure 9-7 illustrates how water, fiber, and fat influence energy density, and the accompanying how to fea- ture compares foods based on their energy density. -foods containing water, those rich in fiber, and those low in fat help to lower energy density, providing more satiety for table 9-4 1600-kcalorie diets daily amounts from each food group for 1000- to food group 1000 kcalories 1200 kcalories 1400 kcalories 1600 kcalories fruit vegetables grains meat and legumes milk oils 1 c 1 c 3 oz 2 oz 3 c 3 tsp 1 c 11/2 c 4 oz 3 oz 3 c 3 tsp 11/2 c 11/2 c 5 oz 4 oz 3 c 3 tsp 11/2 c 2 c 5 oz 5 oz 3 c 4 tsp note: the usda food guide patterns for 1000-, 1200-, and 1400-kcalories were designed for children and provided 2 cups milk. -they were modified here to include an additional cup of milk, as 3 cups per day is recommended for all adults. -the discretionary kcalorie allowance for these patterns is about 100 kcalories. -weight management: overweight, obesity, and underweight 297 figure 9-7 energy density decreasing the energy density (kcal/g) of foods allows a person to eat satisfying portions while still reducing energy intake. -to lower energy density, select foods high in water or fiber and low in fat. ) -l l a ( o i g g u r r a f w e h t t a m selecting grapes with their high water content instead of raisins increases the volume and cuts the energy intake in half. -even at the same weight and similar serving sizes, the fiber-rich broccoli delivers twice the fiber of the potatoes for about one-fourth the energy. -by selecting the water-packed tuna (on the right) instead of the oil-packed tuna (on the left), a person can enjoy the same amount for fewer kcalories. -fewer kcalories.90 because a low-energy-density diet is a low-fat, high-fiber diet rich in many vitamins and minerals, it supports good health in addition to weight loss.91 remember water water helps with weight management in several ways. -for one, foods with high water content (such as broth-based soups) increase fullness, reduce hunger, and consequently reduce energy intake. -for another, drinking water fills the stomach between meals and satisfies thirst without adding kcalories. -the average u.s. diet delivers an estimated 75 to 150 kcalories a day from sweetened beverages.92 simply replacing nutrient-poor, energy-dense beverages with water could save a per- son up to 15 pounds a year. -water also helps the gi tract adapt to a high-fiber diet. -focus on fiber healthy meals and snacks center on high-fiber foods. -fresh fruits, vegetables, legumes, and whole grains offer abundant vitamins, minerals, and fiber but little fat. -consequently, high-carbohydrate diets rich in fiber tend to be relatively low in energy and high in nutrients.93 high-fiber foods also require effort to eat an added bonus. -eating fiber-rich fruits and vegetables reduces energy density, lowers kcalorie intake, and promotes how to compare foods based on energy density chapter 2 described how to evaluate foods based on their nutrient density their nutrient contribution per kcalorie. -another way to evaluate foods is to con- sider their energy density their energy contribution per gram. -this example compares carrot sticks with french fries. -the conclusion is no surprise, but under- standing the mathematics may offer valuable insight into the concept of en- ergy density. -a carrot weighing 72 grams delivers 31 kcalories. -to calculate the energy density, divide kcalories by grams: 31 kcal (cid:5) 0.43 kcal/g 72 g do the same for french fries weighing 50 grams and contributing 167 kcalories: 167 kcal (cid:5) 3.34 kcal/g 50 g the more kcalories per gram, the greater the energy density. -french fries are more energy dense than carrots. -they provide more energy per gram and per bite. -considering a food s energy density is especially useful in planning diets for weight management. -foods with a high energy density help with weight gain, whereas foods with a low energy density help with weight loss. -o i g g u r r a f w e h t t a m to practice comparing foods based on energy den- sity, log on www.thomsonedu.com/thomsonnow, then go to chapter 9, then go to how to. -298 chapter 9 s i b r o c if you want to lose weight, steer clear of the empty kcalories in fancy coffee drinks. -a 16-oz caf mocha delivers 400 kcalories half of them from fat. -satiety.94 the satiety signal indicating fullness is sent after a 20-minute lag, so a person who slows down and savors each bite eats less before the signal reaches the brain. -of course, much depends on whether the person pays attention to internal satiety signals and stops eating or, instead, responds to external cognitive influ- ences and continues. -choose fats sensibly ideally, a weight-loss diet is both high in fiber and low in fat. -lowering the fat content of a food lowers its energy density for example, se- lecting fat-free milk instead of whole milk. -that way, a person can consume the usual amount (say, a cup of milk) at a lower energy intake (85 instead of 150 kcalories). -fat has a weak satiating effect, and satiation plays a key role in determining food intake during a meal. -consequently, a person eating a high-fat meal raises energy intake by adding more food and more fat kcalories. -for these reasons, measure fat with extra caution. -less fat in the diet means less fat in the body (re- view p. 163 for strategies to lower fat in the diet). -be careful not to take this advice to extremes, however; too little fat in the diet or in the body carries health risks as well, as chapter 5 explained. -whether a low-fat diet is the best option for weight loss is the subject of some controversy and much debate. -an important point to notice in any discussion on weight-loss diets is total energy intake. -low fat simply means the energy derived from fat is relatively low compared with the total energy intake; it does not mean total energy intake is low. -and reducing energy intake to less than expended is es- sential for weight loss. -one way to lower energy intake is to lower fat intake. -in these cases, adopting a low-fat diet can help with weight loss.95 another currently popular way to lower energy intake is to lower carbohydrate intake. -the highlight that follows this chapter discusses these diets fully, but find- ings from a recent study are worth mentioning here as well.96 in this study, people were randomly assigned to one of two diets either a low-carbohydrate diet or a low-fat diet. -they were given descriptions of the diets and then fed themselves, as would be typical of many dieters. -both groups lost weight, but those on the low- carbohydrate diet lost more weight during the first six months; their diets pro- duced a greater energy deficit. -interestingly, the differences in weight loss between the two groups disappeared by the end of one year. -between six months and one year, weight remained fairly stable in the low-fat group, but regains were evident in the low-carbohydrate group, suggesting that adhering to a low-carbohydrate diet for an extended length of time may be difficult. -these findings highlight an important point: weight loss requires a commitment to long-term changes in food choices. -they also confirm another critical point: weight loss depends on a low en- ergy intake not the proportion of energy nutrients.97 watch for other empty kcalories a person trying to achieve or maintain a healthy weight needs to pay attention not only to fat, but to sugar and alcohol, too.98 using sugar or alcohol for pleasure on occasion is compatible with health as long as most daily choices are of nutrient-dense foods. -not only does alcohol add kcalories, but accompanying mixers can also add both kcalories and fat, especially in creamy drinks such as pi a coladas (review table h7-3 on p. 244). -furthermore, drinking alcohol reduces a person s inhibitions, which can sabotage weight-control efforts at least temporarily. -in summary a person who adopts a lifelong eating plan for good health rather than a diet for weight loss will be more likely to keep the lost weight off. -table 9-5 provides several tips for successful weight management. -weight management: overweight, obesity, and underweight 299 table 9-5 weight-management strategies in general focus on healthy eating and activity habits, not on weight losses or gains. -adopt reasonable expectations about health and fitness goals and about how long it will take to achieve them. -make nutritional adequacy a high priority. -learn, practice, and follow a healthful eating plan for the rest of your life. -participate in some form of physical activity regularly. -adopt permanent lifestyle changes to achieve and maintain a healthy weight. -for weight loss energy out should exceed energy in by about 500 kcalories/day. -increase your physical activity enough to spend more energy than you consume from foods. -emphasize foods with a low energy density and a high nutrient density. -eat small portions. -share a restaurant meal with a friend or take home half for lunch tomorrow. -eat slowly. -limit high-fat foods. -make legumes, whole grains, vegetables, and fruits central to your diet plan. -limit low-fat treats to the serving size on the label. -limit concentrated sweets and alcoholic beverages. -drink a glass of water before you begin to eat and another while you eat. -drink plenty of water throughout the day (8 glasses or more a day). -keep a record of diet and exercise habits; it reveals problem areas, the first step toward improving behaviors. -learn alternative ways to deal with emotions and stresses. -attend support groups regularly or develop supportive relationships with others. -for weight gain energy in should exceed energy out by at least 500 kcalories/day. -increase your food intake enough to store more energy than you spend in exercise. -exercise and eat to build muscles. -expect weight gain to take time (1 pound per month would be reasonable). -emphasize energy-dense foods. -eat at least three meals a day. -eat large portions of foods and expect to feel full. -eat snacks between meals. -drink plenty of juice and milk. -physical activity the best approach to weight management includes physical activity.99 yet among people trying to lose weight, only half are physically active and only half of the active group meet minimal recommendations.100 to prevent weight gains and support weight losses, current recommendations advise 60 minutes of moderately intense physical activity a day in addition to activities of daily life.101 people who combine diet and exercise typically lose more fat, retain more muscle, and regain less weight than those who only follow a weight-loss diet. -even when people who include physical activity in their weight-management program do not lose more weight, they seem to follow their diet plans more closely and maintain their losses better than those who do not exercise. -consequently, they benefit from taking in a little less energy as well as from expending a little more energy in physical ac- tivity. -importantly, those who exercise reduce abdominal obesity and improve their blood pressure, insulin resistance, and cardiorespiratory fitness, regardless of weight loss.102 chapter 14 presents the many health benefits of physical activity; the focus here is on its role in weight management. -300 chapter 9 the key to good health is to combine sensible eating with regular exercise. -this postexercise effect raises the energy expenditure of exercise by about 15 percent. -to test your understanding of these concepts log on to www.thomsonedu.com/ thomsonnow. -dietary guidelines for americans 2005 to help manage body weight and prevent gradual, unhealthy body weight gain in adulthood, engage in approximately 60 minutes of moder- ate- to vigorous-intensity activity on most days of the week while not ex- ceeding kcaloric intake requirements. -i s b r o c / w e h c e k i m activity and energy expenditure table 8-2 (p. 255) shows how much energy each of several activities uses. -the number of kcalories spent in an activity depends on body weight, intensity, and duration. -for example, a person who weighs 150 pounds and walks 31/2 miles in 60 minutes expends about 315 kcalories. -that same person running 3 miles in 30 minutes uses a similar amount. -by comparison, a 200- pound person running 3 miles in 30 minutes expends an additional 100 kcalories or so. -the goal is to expend as much energy as your time allows. -the greater the energy deficit created by exercise, the greater the fat loss. -and be careful not to compensate for the energy spent in exercise by eating more food. -otherwise, energy balance won t shift and fat loss will be less significant. -activity and discretionary kcalorie allowance chapter 2 introduced the dis- cretionary kcalorie allowance as the difference between the kcalories needed to sup- ply nutrients and those needed to maintain energy balance. -because exercise expends energy, the energy allowance to maintain balance increases with increased physical activity yet the energy needed to deliver needed nutrients remains about the same. -in this way, physical activity increases the discretionary kcalorie al- lowance (see figure 9-8). -having a larger discretionary kcalorie allowance puts a lit- tle more wiggle room in a weight-loss diet for such options as second helpings, sweet treats, or alcoholic beverages on occasion. -of course, selecting nutrient-dense foods and not using discretionary kcalories will maximize weight loss. -activity and metabolism activity also contributes to energy expenditure in an indirect way by speeding up metabolism. -it does this both immediately and over the long term. -on any given day, metabolism remains slightly elevated for several hours after intense and prolonged exercise. -over the long term, a person who en- gages in daily vigorous activity gradually develops more lean tissue. -metabolic rate rises accordingly, and this supports continued weight loss or maintenance. -activity and body composition physically active people have less body fat than sedentary people do even if they have the same bmi. -physical activity, even figure 9-8 animated! -influence of physical activity on discretionary kcalorie allowance energy allowance to maintain weight discretionary kcalorie allowance energy intake to meet nutrient needs 2400 2000 1500 1000 500 0 s e i r o a c k l sedentary person active person weight management: overweight, obesity, and underweight 301 without weight loss, changes body composition: body fat decreases and lean body mass increases. -furthermore, exercise specifically decreases abdominal fat.103 activity and appetite control many people think that exercising will make them eat more, but this is not entirely true. -active people do have healthy appetites, but immediately after an intense workout, most people do not feel like eating. -they may be thirsty and want to shower, but they are not hungry. -the body has released fuels from storage to support the exercise, so glucose and fatty acids are abundant in the blood. -at the same time, the body has suppressed its digestive functions. -hard physical work and eating are not compatible. -a person must calm down, put energy fuels back in storage, and relax before eating. -at that time, a physically active per- son may eat more than a sedentary person, but not so much as so fully compensate for the kcalories expended in exercise.104 exercise may help curb the inappropriate appetite that accompanies boredom, anxiety, or depression. -weight-management programs encourage people who feel the urge to eat when not hungry to go out and exercise instead. -the activity passes time, relieves anxiety, and prevents inappropriate eating. -activity and psychological benefits activity also helps reduce stress. -because stress itself cues inappropriate eating for many people, activity can help here, too. -in addition, the fit person looks and feels healthy and, as a result, gains self-esteem. -high self-esteem motivates a person to persist in seeking good health and fitness, which keeps the beneficial cycle going. -choosing activities clearly, physical activity is a plus in a weight-management program. -what kind of physical activity is best? -people should choose activities that they enjoy and are willing to do regularly. -what schedule of physical activity is best? -it doesn t matter; whether a person chooses several short bouts of exercise or one continuous workout, the fitness and weight-loss benefits are the same and any ac- tivity is better than being sedentary. -health care professionals frequently advise people to engage in activities of low- to-moderate intensity for a long duration, such as an hour-long, fast-paced walk. -the reasoning behind such advice is that people exercising at low-to-moderate in- tensity are more likely to stick with their activity for longer times and are less likely to injure themselves. -a person who stays with an activity routine long enough to enjoy the rewards will be less inclined to give it up and will, over the long term, reap many health benefits. -activity of low-to-moderate intensity that expends at least 2000 kcalories per week is especially helpful for weight management. -higher levels produce even greater losses.105 in addition to exercise, a person can incorporate hundreds of energy-expending activities into daily routines: take the stairs instead of the elevator, walk to the neighbor s apartment instead of making a phone call, and rake the leaves instead of using a blower. -remember that sitting uses more kcalories than lying down, standing uses more kcalories than sitting, and moving uses more kcalories than standing. -a 175-pound person who replaces a 30-minute television program with a 2-mile walk a day can expend enough energy to lose (or at least not gain) 18 pounds in a year. -meeting an activity goal of 10,000 steps a day helps to support a healthy bmi.106 by wearing a pedometer, a person can easily track a day s activ- ities without measuring miles or watching the clock. -the point is to be active. -walk. -run. -swim. -dance. -cycle. -climb. -skip. -do whatever you enjoy doing and do it often. -spot reducing people sometimes ask about spot reducing. -unfortunately, mus- cles do not own the fat that surrounds them. -fat cells all over the body release fat in response to the demand of physical activity for use by whatever muscles are ac- tive. -no exercise can remove the fat from any particular area. -exercise can help with trouble spots in another way, though. -the trouble spot for most men is the abdomen, their primary site of fat storage. -during aerobic ex- ercise, abdominal fat readily releases its stores, providing fuel to the physically ac- tive body. -with regular exercise and weight loss, men will deplete these abdominal benefits of physical activity in a weight- management program: short-term increase in energy expenditure (from exercise and from a slight rise in metabolism) long-term increase in bmr (from an increase in lean tissue) improved body composition appetite control stress reduction and control of stress eating physical, and therefore psychological, well-being improved self-esteem chapter 14 presents additional benefits of physical activity. -for an active life, limit sedentary activities, engage in strength and flexibility activities, enjoy leisure activities often, engage in vig- orous activities regularly, and be as active as possible every day (see the activity pyra- mid in chapter 14). -estimated energy expended when walking at a moderate pace = 1 kcal/mi/kg body wt. -302 chapter 9 fat stores before those in the lower body. -women may also deplete abdominal fat with exercise, but their trouble spots are more likely to be their hips and thighs. -in addition to aerobic activity, strength training can help to improve the tone of muscles in a trouble area, and stretching to gain flexibility can help with associ- ated posture problems. -a combination of aerobic, strength, and flexibility workouts best improves fitness and physical appearance. -in summary physical activity should be an integral part of a weight-control program. -phys- ical activity can increase energy expenditure, improve body composition, help control appetite, reduce stress and stress eating, and enhance physical and psychological well-being. -environmental influences chapter 8 described how hormones regulate hunger, satiety, and satiation, but people don t always pay close attention to such internal signals. -instead, their eat- ing behaviors are often dictated by environmental factors. -environmental factors include those surrounding the eating experience as well as those pertaining to the food itself.107 changing any of these factors can influence how much a person eats.108 atmosphere the environment surrounding a meal or snack influences its dura- tion. -when the lighting, d cor, aromas, and sounds of an environment are pleas- ant and comfortable, people tend to spend more time eating and thus eat more. -a person needn t eat under neon lights with offensive music to eat less, of course. -in- stead, after completing a meal, remove food from the table and enjoy the ambi- ence without the presence of visual cues to stimulate additional eating. -accessibility among the strongest influences on how much we eat is the acces- sibility, ease, and convenience of obtaining food. -in general, the less effort needed to obtain food, the more likely food will be eaten. -are you more likely to eat if half a leftover pizza is in your refrigerator or if you have to drive to the gro- cery store, buy a frozen pizza, and bake it for 45 minutes? -having food nearby and visible encourages eating. -in one study, secretaries ate more chocolates when the candy was on their desks than when they had to walk six feet.109 inter- estingly, the secretaries underestimated the amount of chocolates they had eaten when the candy was on their desk and overestimated when it was a short dis- tance away. -the message is clear for people wanting to eat less candy (or any other tempting item) keep it out of sight and in an inconvenient place (or don t even buy it). -socializing people tend to eat more when socializing with others. -pleasant con- versations extend the duration of a meal, allowing a person more time to eat more, and research confirms that the longer the meal, the greater the consump- tion.110 in addition, by taking a visual cue from companions, a person might eat more when others at the table, clean their plates, or go to the buffet line for sec- onds. -one way to eat less is to pace yourself with the person who seems to be eat- ing the least and slowest. -social interactions also distract a person from paying attention to how much has been eaten. -in some cases, socializing with friends dur- ing a meal may provide comfort and lower a person s motivation to limit consump- tion. -in other cases, socializing with unfamiliar people during a meal during a job interview or blind date, for example may create stress and reduce food consump- tion. -to eat less while socializing, pay attention to portion sizes. -distractions distractions influence food intake by initiating eating, interfering with internal controls to stop eating, and extending the duration of eating. -some weight management: overweight, obesity, and underweight 303 people start eating dinner when a favorite television program comes on, regard- less of hunger. -other people continue eating breakfast until they finish reading the newspaper. -such mindless eating can easily become overeating. -in addition to influencing the start and stop of a meal, distractions interfere with a person s ability to monitor and regulate how much is consumed.111 do you eat more popcorn when you are engrossed in a movie or if you are paying attention to how much popcorn you are eating? -if distractions are a part of the eating experi- ence, extra care is needed to control portion sizes. -presence the mere sight (or smell, or even thought) of a food can prompt a person to start eating regardless of hunger. -the chocolates in the clear candy dishes on the secretaries desks were eaten much faster than those in opaque containers.112 s e g a m i y t t e g / y a d a n n o d variety when offered a variety of foods, or a variety of flavors of the same food, people tend to eat more. -interestingly, they tend to eat more even when variety is only perceived. -given six flavors of jelly beans, people will eat more when offered an assorted mixture than when presented with the exact same flavors and quan- tities sorted in a sectioned container.113 variety is pleasing and distracting two factors that slow the eating experience and delay satiation.114 to limit intake, then, focus on a limited number of foods per meal. -be careful not to misunderstand and abandon variety in diet planning. -eat- ing a variety of foods from each of the food groups is still a healthy plan just not all at one meal. -package and portion sizes as noted earlier, the sizes of packages in grocery stores and portion sizes at restaurants and at home have increased dramatically in recent decades, contributing to the increase in obesity in the united states.115 put simply, we tend to clean our plates and finish the package. -the larger the bag of potato chips, the greater the intake.116 to keep from overeating, repackage snacks into smaller con- tainers and eat them from a plate, not directly from the package. -serving containers we often use plates, utensils, and glasses as visual cues to guide our decisions on how much to eat and drink.117 if you plan to eat a bowl of ice cream, it matters whether the bowl you select holds 8 ounces or 24 ounces. -even the size of the serving container matters. -students took more and ate more snacks when serving from two large bowls instead of from four medium bowls.118 large dinner plates and wide glasses create illusions and misperceptions about quantities consumed. -a scoop of mashed potatoes on a small plate looks larger than the same-size scoop on a large plate, leading a person to underestimate the amount of food eaten.119 to control portion sizes, use small bowls and plates, small serving spoons, and tall, narrow glasses.120 behavior and attitude behavior and attitude play important roles in supporting efforts to achieve and maintain appropriate body weight and composition. -behavior modification fo- cuses on how to change behaviors to increase energy expenditure and decrease en- ergy intake.121 a person must commit to taking action. -adopting a positive, matter-of-fact attitude helps to ensure success. -healthy eat- ing and activity choices are an essential part of healthy living and should simply be incorporated into the day much like brushing one s teeth or wearing a safety belt. -become aware of behaviors to solve a problem, a person must first identify all the behaviors that created the problem. -keeping a record will help to identify eating and exercise behaviors that may need changing (see figure 9-9, p. 304). -it will also establish a baseline against which to measure future progress. -change behaviors strategies focus on learning desired eating and exercise be- haviors and eliminating unwanted behaviors. -with so many possible behavior changes, a person can choose where to begin. -start simply and don t try to master eating from the package while distracted by television is a weight-gaining combination. -examples of behavioral strategies to sup- port weight change: do not grocery shop when hungry. -eat slowly (pause during meals, chew thoroughly, put down utensils between bites). -exercise when watching television. -behavior modification: the changing of behavior by the manipulation of antecedents (cues or environmental factors that trigger behavior), the behavior itself, and consequences (the penalties or rewards attached to behavior). -304 chapter 9 figure 9-9 food record the entries in a food record should include the times and places of meals and snacks, the types and amounts of foods eaten, and a description of the individ- ual s feelings when eating. -the diary should also record physical activities: the kind, the intensity level, the duration, and the person s feelings about them. -diet analysis programs help people identify high-kcalorie foods and monitor their eating habits. -them all at once. -attempting too many changes at one time can be overwhelming. -pick one trouble area that is manageable and start there. -practice a desired behavior until it becomes routine. -then select another trouble area to work on, and so on. -another bit of advice along the same lines: don t try to tackle major changes during a particularly stressful time of life. -personal attitude for many people, overeating and being overweight have be- come an integral part of their identity. -those who fully understand their personal re- lationships with food are best prepared to make healthful changes in eating and exercise behaviors. -sometimes habitual behaviors that are hazardous to health, such as smoking or drinking alcohol, contribute positively by helping people adapt to stressful situa- tions. -similarly, many people overeat to cope with the stresses of life. -to break out of that pattern, they must first identify the particular stressors that trigger the urge to overeat. -then, when faced with these situations, they must learn and practice problem-solving skills that will help them to respond appropriately.122 all this is not to imply that psychological therapy holds the magic answer to a weight problem. -still, efforts to improve one s general well-being may result in healthy eating and activity habits even when weight loss is not the primary goal. -when the problems that trigger the urge to overeat are resolved in alternative ways, people may find they eat less. -they may begin to respond appropriately to internal cues of hunger rather than inappropriately to external cues of stress. -sound emotional health supports a person s ability to take care of physical health in all ways including nutrition, weight management, and fitness. -support groups group support can prove helpful when making life changes. -some people find it useful to join a group such as take off pounds sensibly (tops), weight watchers (ww), overeaters anonymous (oa), or others. -some di- eters prefer to form their own self-help groups or find support online. -the internet offers numerous opportunities for weight-loss education and counseling that may be effective alternatives to face-to-face programs.123 as always, consumers need to choose wisely and avoid rip-offs. -weight management: overweight, obesity, and underweight 305 in summary a surefire remedy for obesity has yet to be found, although many people find a combination of the approaches just described to be most effective. -diet and exercise shift energy balance so that more energy is being expended than is taken in. -physical activity increases energy expenditure, builds lean tissue, and improves health. -energy intake should be reduced by 500 to 1000 kcalo- ries per day, depending on starting body weight and usual food intake. -behav- ior modification retrains habits to support a healthy eating and exercise plan. -this treatment package requires time, individualization, and sometimes the assistance of a registered dietitian. -weight maintenance people who are successful often experience much of their weight loss within half a year and then reach a plateau. -this slowdown can be disappointing, but it should be recognized as an opportunity for the body to adjust to its new weight. -reaching a plateau provides a little relief from the distraction of weight-loss dieting. -an appro- priate goal at this point is to continue the eating and activity behaviors that will maintain weight. -attempting to lose additional weight at this point would require major effort and would almost certainly meet with failure. -the prevalence of successful weight-loss maintenance is difficult to deter- mine, in part because researchers have used different criteria. -some look at success after one year and others after five years; some quantify success as 10 or more pounds lost and others as 5 or 10 percent of initial body weight lost. -furthermore, most research studies examine the success of one episode of weight loss in a struc- tured program, but this scenario does not necessarily reflect the experiences of the general population. -in reality, most people have lost weight several times in their lifetimes and did so on their own, not in a formal program. -almost 50 percent of people who intentionally lost weight have successfully maintained the loss for at least a year.124 those who are successful in maintaining their weight loss have established vigorous exercise regimens and careful eating patterns, taking in less energy and a lower percentage of kcalories from fat than the national average.125 be- cause these people are more efficient at storing fat, they do not have the same flexibility in their food and activity habits as their friends who have never been overweight. -with weight loss, metabolism shifts downward so that formerly overweight people require less energy than might be expected given their cur- rent body weight and body composition. -consequently, to keep weight off, they must either eat less or exercise more than people the same size who have never been obese. -physical activity plays a key role in maintaining weight.126 those who exercise vigorously are far more successful than those who are inactive. -on average, weight maintenance requires a person to expend about 2000 kcalories in physical activity per week.127 to accomplish this, a person might exercise either moderately (such as brisk walking) for 60 minutes a day or vigorously (such as fast bicycling) for 35 minutes a day, for example. -being active during both work hours and leisure time also helps a person to maintain weight loss.128 e l i f r e t s a m / z e m o g k c i r maintaining a healthy body weight requires maintaining the vigorous physical activities and careful eating habits that supported weight loss. -dietary guidelines for americans 2005 to sustain weight loss in adulthood, participate in at least 60 to 90 minutes of moderately intense physical activity daily while not exceeding kcaloric intake requirements. -some people may need to consult with a healthcare provider before participating in this level of activity. -successful weight-loss maintenance: achieving a weight loss of at least 10 percent of initial body weight and maintaining the loss for at least one year. -306 chapter 9 to prevent weight gain: eat regular meals and limit snacking. -drink water instead of high-kcalorie bev- erages. -select sensible portion sizes and limit daily energy intake to no more than energy expended. -become physically active and limit sedentary activities. -in addition to limiting energy intake and exercising regularly, one other strategy may help with weight maintenance: frequent self-monitoring. -people who weigh themselves periodically and monitor their eating and exercise habits regularly can detect weight gains in the early stages and promptly initiate changes to prevent relapse.129 losing weight and maintaining the loss may not be as easy as gaining the weight in the first place, but it is possible. -those who have been successful find that it gets easier with time the changes in diet and activity patterns become permanent.130 prevention given the information presented up to this point in the chapter, the adage an ounce of prevention is worth a pound of cure seems particularly apropos. -prevent- ing weight gain would benefit almost everybody.131 obesity is a major risk factor for numerous diseases, and losing weight is challenging and often temporary. -strategies for preventing weight gain are very similar to those for losing weight, with one ex- ception: they begin early. -over the years, they become an integral part of a person s life. -it is much easier for a person to resist doughnuts for breakfast if he rarely eats them. -similarly, a person will have little trouble walking each morning if she has al- ways been active. -dietary guidelines for americans 2005 to prevent gradual weight gain over time, make small decreases in food and beverage kcalories and increase physical activity. -public health programs has anyone in the united states not heard the message that obesity raises the risks of chronic diseases and that overweight people should aim for a healthy weight by eat- ing sensibly and becoming physically active? -not likely. -yet implementing such advice is difficult in an environment of abundant food and physical inactivity. -to successfully treat obesity, we may have to change the environment in which we live through pub- lic health law.132 table 9-6 provides examples of public health strategies that have been suggested to improve our nation s nutrition environment. -some of these strate- table 9-6 suggested public health strategies strategies examples of suggested nutritional strategies examples of successful nonnutritional strategies impose safety standards to reduce the potential for harm. -regulate the energy or fat density of foods. -regulate the size of packages of high-fat foods. -mandate safety glass in automobiles. -regulate the lead content of paint. -control commercial advertising to limit the influence of harmful products. -improve nutrition labeling and product restrict cigarette advertising (especially when packaging. -restrict the promotion of high-fat foods (especially when directed at children). -directed at children). -add health warnings to alcoholic beverages. -control the conditions under which products are sold to limit exposure to hazardous substances. -remove high-fat, low nutrient density foods mandate minimum-age laws for the use of from school vending machines. -tobacco, alcohol, and automobiles. -restrict the number of vendors licensed to restrict the number of vendors licensed to sell control prices to reduce consumption. -sell high-fat foods. -alcohol. -tax soft drinks and other foods high in tax alcohol and tobacco. -kcalories, fat, or sugar. -sources: adapted from l. o. gostin, law as a tool to facilitate healthier lifestyles and prevent obesity, journal of the american medical association 297 (2007):87 90; m. nestle and m. f. jacobson, halting the obesity epidemic: a public health policy approach, public health reports 115 (2000): 12 24. weight management: overweight, obesity, and underweight 307 reminder: underweight is a body weight so low as to have adverse health effects; it is generally defined as bmi (cid:2)18.5. gies may seem radical, but dramatic measures may be needed if we are to curb the obesity epidemic that is sweeping across the nation.133 dozens of bills and resolutions are pending in congress.134 whether changes in public policy such as a tax on snack foods will influence diet habits or simply generate revenues remains to be seen.135 in summary preventing weight gains and maintaining weight losses require vigilant attention to diet and physical activity. -taking care of oneself is a lifelong responsibility. -underweight underweight is a far less prevalent problem than overweight, affecting no more than 5 percent of u.s. adults (review figure 8-7 on p. 260). -whether the underweight person needs to gain weight is a question of health and, like weight loss, a highly in- dividual matter. -people who are healthy at their present weight may stay there; there are no compelling reasons to try to gain weight. -those who are thin because of malnourishment or illness, however, might benefit from a diet that supports weight gain. -medical advice can help make the distinction. -thin people may find gaining weight difficult. -those who wish to gain weight for appearance s sake or to improve their athletic performance need to be aware that healthful weight gains can be achieved only by physical conditioning combined with high energy intakes. -on a high-kcalorie diet alone, a person may gain weight, but it will be mostly fat. -even if the gain improves appearance, it can be detrimental to health and might impair athletic performance. -therefore, in weight gain, as in weight loss, physical activity and energy intake are essential components of a sound plan. -problems of underweight the causes of underweight may be as diverse as those of overweight genetic ten- dencies, hunger, appetite, and satiety irregularities; psychological traits; and meta- bolic factors. -habits learned early in childhood, especially food aversions, may perpetuate themselves. -the demand for energy to support physical activity and growth often contributes to underweight. -an active, growing boy may need more than 4000 kcalories a day to maintain his weight and may be too busy to take time to eat adequately. -under- weight people find it hard to gain weight due, in part, to their expenditure of energy in adaptive thermogenesis. -so much energy may be expended adapting to a higher food intake that at first as many as 750 to 800 extra kcalories a day may be needed to gain a pound a week. -like those who want to lose weight, people who want to gain must learn new habits and learn to like new foods. -they are also similarly vulnera- ble to potentially harmful schemes and would be wise to review the consumer bill of rights on p. 290, using weight gain instead of weight loss where appropriate. -as described in highlight 8, the underweight condition anorexia nervosa some- times develops in people who employ self-denial to control their weight. -they go to such extremes that they become severely undernourished, achieving final body weights of 70 pounds or even less. -the distinguishing feature of a person with anorexia nervosa, as opposed to other underweight people, is that the starvation is intentional. -(see highlight 8 for a review of anorexia nervosa and other eating disorders.) -weight-gain strategies weight-gain strategies center on eating energy-dense foods that provide many kcalories in a small volume and exercising to build muscle. -by using the usda food 308 chapter 9 guide recommendations for the higher kcalorie levels (see table 2-3 on p. 41), a per- son can gain weight while meeting nutrient needs. -energy-dense foods energy-dense foods (the very ones eliminated from a suc- cessful weight-loss diet) hold the key to weight gain. -pick the highest-kcalorie items from each food group that is, milk shakes instead of fat-free milk, salmon instead of snapper, avocados instead of cucumbers, a cup of grape juice instead of a small apple, and whole-wheat muffins instead of whole-wheat bread. -because fat provides more than twice as many kcalories per teaspoon as sugar does, fat adds kcalories without adding much bulk. -although eating high-kcalorie, high-fat foods is not healthy for most people, it may be essential for an underweight individual who needs to gain weight. -an un- derweight person who is physically active and eating a nutritionally adequate diet can afford a few extra kcalories from fat. -for health s sake, it is wise to select foods with monounsaturated and polyunsaturated fats instead of those with saturated or trans fats: for example, saut ing vegetables in olive oil instead of butter or hydro- genated margarine. -regular meals daily people who are underweight need to make meals a priority and take the time to plan, prepare, and eat each meal. -they should eat at least three healthy meals every day and learn to eat more food within the first 20 minutes of a meal. -another suggestion is to eat meaty appetizers or the main course first and leave the soup or salad until later. -large portions underweight people need to learn to eat more food at each meal. -for example, they can add extra slices of ham and cheese on the sandwich for lunch, drink milk from a larger glass, and eat cereal from a larger bowl. -the person should expect to feel full. -most underweight individuals are accus- tomed to small quantities of food. -when they begin eating significantly more, they feel uncomfortable. -this is normal and passes over time. -extra snacks since a substantially higher energy intake is needed each day, in addition to eating more food at each meal, it is necessary to eat more frequently. -be- tween-meal snacks do not interfere with later meals; they can readily lead to weight gains.136 for example, a student might make three sandwiches in the morning and eat them between classes in addition to the day s three regular meals. -snacking on dried fruit, nuts, and seeds is also an easy way to add kcalories. -juice and milk beverages provide an easy way to increase energy intake. -consider that 6 cups of cranberry juice add almost 1000 kcalories to the day s intake. -kcalories can be added to milk by mixing in powdered milk or packets of instant breakfast. -for people who are underweight due to illness, concentrated liquid formulas are often recommended because a weak person can swallow them easily. -a physician or registered dietitian can recommend high-protein, high-kcalorie formulas to help an underweight person maintain or gain weight. -used in addition to regular meals, these supplements can help considerably. -exercising to build muscles to gain weight, use strength training primarily, and increase energy intake to support that exercise. -eating extra food will then support a gain of both muscle and fat. -an additional 500 to 1000 kcalories a day above normal energy needs is enough to support the exercise as well as the building of muscle.137 in summary both the incidence of underweight and the health problems associated with it are less prevalent than overweight and its associated problems. -to gain weight, a person must train physically and increase energy intake by selecting energy-dense foods, eating regular meals, taking larger portions, and consum- ing extra snacks and beverages. -table 9-5 (p. 299) includes a summary of weight-gain strategies. -weight management: overweight, obesity, and underweight 309 nutrition portfolio www.thomsonedu.com/thomsonnow to enjoy good health and maintain a reasonable body weight, combine sensible eating habits and regular physical activity. -calculate your bmi and consider whether you need to lose or gain weight for the sake of good health. -reflect on your weight over the past year or so and explain any weight gains or loses. -describe the potential risks and possible benefits of fad diets and over-the- counter weight-loss drugs or herbal supplements. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 9, then to nutrition on the net. -search for obesity and weight control at the u.s. gov- ernment health information site: www.healthfinder.gov review the clinical guidelines on the identification, eval- uation, and treatment of overweight and obesity in adults: www.nhlbi.nih.gov/guidelines/obesity/ ob_home.htm learn about the drugs used for weight loss from the cen- ter for drug evaluation and research: www.fda.gov/cder learn about weight control and the win program from the weight-control information network: www.win.niddk.nih.gov visit weight-loss support groups, such as take off pounds sensibly (tops), overeaters anonymous (oa), and weight watchers: www.tops.org, www.oa.org, and www .weightwatchers.com see what the obesity professionals think at the north american association for the study of obesity and the american society for bariatric surgery: www.naaso.org and www.asbs.org consider the nondietary approaches of hugs interna- tional: www.hugs.com learn about the 10,000 step program from shape up america! -: www.shapeup.org/10000steps.html find helpful information on achieving and maintaining a healthy weight from the calorie control council: www.caloriecontrol.org learn how to end size discrimination and improve the quality of life for fat people from the national association to advance fat acceptance: www.naafa.org find good advice on starting a weight-loss program from the partnership for healthy weight management: www.consumer.gov/weightloss consider ways to live a healthy life at any weight: www.bodypositive.com nutrition calculations for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 9, then to nutrition calculations. -these problems give you practice in doing simple energy- balance calculations (see p. 314 for answers). -once you have mastered these examples, you will be prepared to examine your own food choices. -be sure to show your calculations for each problem. -1. critique a commercial weight-loss plan. -consumers spend billions of dollars a year on weight-loss programs such as slim-fast, sweet success, weight watchers, nutri/system, jenny craig, optifast, medifast, and formula one. -one such plan calls for a milk shake in the morning, at noon, and as an afternoon snack and a sensible, balanced, low- fat dinner in the evening. -one shake mixed in 8 ounces of vitamin a- and d-fortified fat-free milk offers 190 kcalo- ries; 32 grams of carbohydrate, 13 grams of protein, and 1 gram of fat; at least one-third of the daily value for all vitamins and minerals; plus 2 grams of fiber. -a. calculate the kcalories and grams of carbohydrate, protein, and fat that three shakes provide. -310 chapter 9 b. how do these values compare with the criteria c. suppose a person simply can t do this. -try to re- listed in item 2 in table h9-4 on p. 320? -c. plan a sensible, balanced, low-fat dinner that will help make this weight-loss plan adequate and bal- anced. -now, how do the day s totals compare with the criteria in item 2 in table h9-4 on p. 320? -d. critique this plan using the other criteria described in table h9-4 on p. 320 as a guide. -2. evaluate a weight-gain attempt. -people attempting to gain weight sometimes have a hard time because they choose low-kcalorie, high-bulk foods that make it hard to consume enough energy. -consider the following lunch: a chef s salad consisting of 2 cups iceberg lettuce, 1 whole tomato, 1 ounce swiss cheese, 1 ounce roasted ham (extra lean), 1 hard-boiled egg, 1 2 cup grated carrots, and 1 4 cup thousand island salad dressing. -if you weighed these foods, you d find that they totaled 442 grams. -this is a pretty filling meal. -a. the meal provides 459 kcalories. -what is the energy density of this meal, expressed in kcalories per gram? -b. to gain weight, this person is advised to eat an additional 500 kcalories at this meal. -using foods with this same energy density, how much more chef s salad will this person have to eat? -study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. describe how body fat develops, and suggest some rea- sons why it is difficult for an obese person to maintain weight loss. -(pp. -282 283) 2. what factors contribute to obesity? -(pp. -283 288) 3. list several aggressive ways to treat obesity, and explain why such methods are not recommended for every over- weight person. -(pp. -292 293) 4. discuss reasonable dietary strategies for achieving and maintaining a healthy body weight. -(pp. -294 299) 5. what are the benefits of increased physical activity in a weight-loss program? -(pp. -299 302) 6. describe the behavioral strategies for changing an indi- vidual s dietary habits. -what role does personal attitude play? -(pp. -303 305) 7. describe strategies for successful weight gain. -(pp. -307 308) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 314. -1. with weight loss, fat cells: a. decrease in size only. -b. decrease in number only. -c. decrease in both number and size. -d. decrease in number, but increase in size. -duce the bulk of this meal by replacing some of the lettuce with more energy-dense foods. -delete 1 cup lettuce from the salad and add another ounce roast ham and 1 ounce cheddar cheese. -show how these changes influence the weight and kcalories of this meal. -(use appendix h.) item no./food weight (g) energy (kcal) original totals: minus: #5083 lettuce, 1 c plus: 442 459 (cid:6)______________ (cid:6)______________ #12212 roast ham, 1 oz #1007 cheddar cheese, 1 oz (cid:7)______________ (cid:7)______________ (cid:7)______________ (cid:7)______________ totals: ________________ ________________ d. how many kcalories did the changes add? -e. how much more weight of food did these changes add? -this exercise should reveal why people attempting to gain weight are advised to add high-fat items, within reason, to their daily meals. -2. obesity is caused by: a. overeating. -b. inactivity. -c. defective genes. -d. multiple factors. -3. the protein produced by the fat cells under the direction of the ob gene is called: a. leptin. -b. serotonin. -c. sibutramine. -d. phentermine. -4. the biggest problem associated with the use of drugs in the treatment of obesity is: a. cost. -b. chronic dosage. -c. ineffectiveness. -d. adverse side effects. -5. a realistic goal for weight loss is to reduce body weight: a. down to the weight a person was at age 25. b. down to the ideal weight in the weight-for-height tables. -c. by 10 percent over six months. -d. by 15 percent over three months. -6. a nutritionally sound weight-loss diet might restrict daily energy 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composition on substrate utilization and hunger, american journal of clinical nutrition 76 (2002): 518-528. -137. position paper: nutrition and athletic performance position of the american dietetic association, dietitians of canada, and the american college of sports medi- cine, journal of the american dietetic associa- tion 100 (2000): 1543-1556. answers nutrition calculations 1. a. three milk shakes provide: 3 (cid:8) 190 kcal (cid:5) 570 kcal; 3 (cid:8) 32 g carbohydrate (cid:5) 96 g carbohydrate; 3 (cid:8) 13 g pro- tein (cid:5) 39 g protein; and 3 (cid:8) 1 g fat (cid:5) 3 g fat. -b. to meet this criteria, the plan needs at least an additional 430 kcalories (1000 kcal (cid:6) 570 kcal (cid:5) 430 kcal); an addi- tional 7 to 17 grams of protein, depending on the person s rda based on gender and age (56 g (cid:6) 39 g (cid:5) 17 g and 46 g (cid:6) 39 g (cid:5) 7 g); an additional 4 grams of carbohydrate (100 g (cid:6) 96 g (cid:5) 4 g); and some additional fat. -c. of course, there are many possible dinners that you could plan. -one might be: salad made with 1 c lettuce, 1 c chopped tomatoes and onions, 1 4 c garbanzo beans, and 2 tbs low-fat dressing 4 oz grilled chicken 1 medium baked potato 1 c summer squash and zucchini 1 c melon cubes this meal brings the day s totals to 1215 kcalories, 90 g of protein, 192 g of carbohydrate, and 13 g of fat, which meets the goals for kcalories, protein, and carbohydrate. -because the milk shake has been fortified, all vitamin and mineral needs are covered as well. -the only possible dietary shortcoming is that the day s percent kcalories from fat is low (only 10%), but because energy and nutrient recom- mendations have been met and the goal is weight loss, this may be acceptable. -d. this weight-loss plan uses a liquid formula rather than foods, making clients dependent on a special device (the formula) rather than teaching them how to make good choices from the conventional food supply. -it provides no information about dropout rates, the long-term success of clients, or weight maintenance after the program ends. -2. a. -459 kcal (cid:9) 442 g (cid:5) 1.04 kcal/g b. more than another whole salad (1.04 kcal/g (cid:8) 500 kcal (cid:5) 520 g) c. item no./food weight (g) energy (kcal) original totals: minus: #5083 lettuce, 1 c plus: #12212 roast ham, 1 oz #1007 cheddar cheese, 1 oz 442 (cid:6)55 (cid:7)28 (cid:7)28 459 (cid:6)6 (cid:7)41 (cid:7)113 totals: 443 g 607 kcal d. 607 kcal (cid:6) 459 kcal (cid:5) 148 kcal added e. 443 g (cid:6) 442 g (cid:5) 1 g added study questions (multiple choice) 1. a 9. d 2. d 3. a 4. d 5. c 6. c 7. d 8. d 10. b highlight 9 the latest and greatest weight-loss diet again to paraphrase william shakespeare, a fad diet by any other name would still be a fad diet. -and the names are legion: the atkins diet, the calories don t count diet, the pro- tein power diet, the carbohydrate addict s diet, the lo-carbo diet, the south beach diet, the zone diet. -* year after year, new and im- proved diets appear on bookstore shelves and circulate among friends. -people of all sizes eagerly try the best diet on the market ever, hoping that this one will really work. -sometimes these diets seem to work for a while, but more often than not, their success is short-lived. -then another diet takes the spotlight. -here s how dr. k. brownell, an obesity researcher at yale university, describes this phenomenon: when i get calls about the latest diet fad, i imagine a trick birth- day cake candle that keeps lighting up and we have to keep blow- ing it out. -realizing that fad diets do not offer a safe and effective plan for weight loss, health professionals speak out, but they never get the candle blown out permanently. -new fad diets can keep making outrageous claims because no one requires their advocates to prove what they say. -fad diet gurus do not have to conduct cred- ible research on the benefits or dangers of their diets. -they can simply make recommendations and then later, if questioned, search for bits and pieces of research that support the conclusions they have already reached. -that s backwards. -diet and health rec- ommendations should follow years of sound research that has been reviewed by panels of scientists before being offered to the public. -because anyone can publish anything in books or on the in- ternet peddlers of fad diets can make unsubstantiated state- ments that fall far short of the truth but sound impressive to the uninformed. -they often offer distorted bits of legitimate research. -they may start with one or more actual facts but then leap from one erroneous conclusion to the next. -anyone who wants to be- lieve these claims has to wonder how the thousands of scientists working on obesity research over the past century could possibly have missed such obvious connections. -table h9-1 (p. 316) pres- ents some of the claims and truths of fad diets. -* the following sources offer comparisons and evaluations of various fad diets for your review: battle of the diet books ii, nutrition action healthletter, july/august 2006, pp. -10 11; b. liebman, weighing the diet books, nutrition action healthletter, january/february 2004, pp. -1 8; s. t. st. jeor and coauthors, dietary protein and weight reduction: a statement for healthcare profession- als from the nutrition committee of the council on nutrition, physical activ- ity, and metabolism of the american heart association, circulation 104 (2001): 1869 1874. i r e g g r e b g n e fad diets come in almost as many shapes and sizes as the people who search them out. -some restrict fats or carbohydrates, some limit portion sizes, some focus on food com- binations, and some claim that a person s ge- netic type or blood type determines the foods best suited to manage weight and prevent disease. -table h9-2 (p. 317) compares some of today s more popular diets. -regardless of their names, many popular diets espouse a carbohydrate-restricted or carbohydrate- modified diet. -some diets claim that all or some types of carbohydrates are bad. -some go so far as to equate carbohydrates with toxic poisons or addictive drugs. -bad car- bohydrates such as sugar, white flour, and potatoes are con- sidered evil because they are absorbed easily and raise blood glucose. -the pancreas then responds by secreting insulin and insulin is touted as the real villain responsible for our nation s epi- demic of obesity. -whether restricting overall carbohydrate intake or replacing certain bad carbohydrates with good carbohy- drates, these diets tend to overemphasize protein. -this highlight examines some of the science and the science fiction behind a few carbohydrate-restricted or carbohydrate-modified, high-pro- tein fad diets. -the diet s appeal perhaps the greatest appeal of fad diets such as the atkins diet is that it turns nutrient recommendations upside down. -foods such as meats and milk products that need to be selected carefully to limit saturated fat can be eaten with abandon on this diet. -grains, legumes, vegetables, and fruits that consumers are told to eat in abundance can now be ignored. -for some people, this is a dream come true: steaks without the potatoes, ribs without the coleslaw, and meatballs without the pasta. -who can resist the promise of weight loss while eating freely from a list of favorite foods? -to lure dieters in, proponents of fad diets often blame current recommendations for our obesity troubles. -they claim that the in- cidence of obesity is rising because we are eating less fat. -such a claim may impress the naive, but it sends skeptical people run- ning for the facts. -true, the incidence of obesity has risen dramat- ically over the past two decades.1 true, our intake of fat has dropped from 35 to 33 percent of daily energy intake.2 such facts might seem to imply that lowering fat intake leads to obesity, but this is an erroneous conclusion. -the percentage declined only be- cause average energy intakes increased by almost 200 kcalories a 315 316 highlight 9 table h9-1 the claims and truths of fad diets the claim: you can lose weight easily. -the truth: most fad diet plans have complicated rules that require you to calculate protein requirements, count carbohy- drate grams, combine certain foods, time meal inter- vals, purchase special products, plan daily menus, and measure serving sizes. -the claim: the truth: you can lose weight by eating a specific ratio of carbo- hydrates, protein, and fat. -weight loss depends on spending more energy than you take in, not on the proportion of energy nutrients. -the claim: this revolutionary diet can reset your genetic code. -the truth: the claim: the truth: you inherited your genes and cannot alter your genetic code. -high-protein diets are popular, selling more than 20 million books, because they work. -weight-loss books are popular because people grasp for quick fixes and simple solutions to their weight prob- lems. -if book sales were an indication of weight-loss success, we would be a lean nation but they re not, and neither are we. -the claim: people gain weight on low-fat diets. -the truth: people can gain weight on low-fat diets if they over- indulge in carbohydrates and proteins while cutting fat; low-fat diets are not necessarily low-kcalorie diets. -but people can also lose weight on low-fat diets if they cut kcalories as well as fat. -the claim: high-protein diets energize the brain. -the truth: the claim: the truth: the claim: the truth: the brain depends on glucose for its energy; the pri- mary dietary source of glucose is carbohydrate, not protein. -thousands of people have been successful with this plan. -authors of fad diets have not published their research findings in scientific journals. -success stories are anec- dotal and failures are not reported. -carbohydrates raise blood glucose levels, triggering insulin production and fat storage. -insulin promotes fat storage when energy intake ex- ceeds energy needs. -furthermore, insulin is only one hormone involved in the complex processes of main- taining the body s energy balance and health. -the claim: eat protein and lose weight. -the truth: for every complicated problem, there is a simple and wrong solution. -day (from 1878 kcalories a day to 2056). -actual fat intake in- creased by 3 grams a day (from 73 grams to 76). -furthermore, fewer than half of us engage in regular physical activity.3 obesity experts blame our high energy intakes and low energy outputs for the increase in obesity. -weight loss, after all, depends on a negative energy balance. -to their credit, some of these diet plans recommend exercise and regular physical activity is an integral component of successful weight loss.4 dieters are also lured into fad diets by sophisticated yet often erroneous explanations of the metabolic consequences of eat- ing certain foods. -terms such as eicosanoids and de novo lipogen- o i g g u r r a f w e h t t a m low-carbohydrate meals overemphasize meat, fish, poultry, eggs, and cheeses, and shun breads, pastas, fruits, and vegetables. -esis are scattered about, often intimidating readers into believing that the authors must be right given their brilliance in under- standing the body. -several of the latest fad diets hold insulin re- sponsible for the obesity problem and the glycemic index as the weight loss solution. -yet, among nutrition researchers, contro- versy continues to surround the questions of whether insulin pro- motes weight gain or a low-glycemic diet fosters weight loss.5 what does insulin do? -among its roles, insulin facilitates the transport of glucose into the cells, the storage of fatty acids as fat, and the synthesis of cholesterol. -it is an anabolic hormone that builds and stores. -true but there s more to the story. -insulin is only one of many factors involved in the body s metabolism of nutrients and regulation of body weight. -furthermore, as chapter 4 s discussion of the glycemic index pointed out, blood glucose and insulin do not always respond to foods as might be expected. -the glycemic effect of a food depends on how the food is ripened, processed, and cooked; the time of day the food is eaten; the other foods eaten with it; and the presence or absence of certain diseases such as type 2 diabetes in the person eating the food.6 thus the glycemic effect of a particular food varies fad diet books mislead people by claiming that each food has a set glycemic effect. -many carbohydrates fruits, vegetables, legumes, and whole grains are rich in fibers that slow glucose absorption and moderate insulin response. -furthermore, there is no clear evidence that elevated blood insulin concentrations pro- mote weight gain in healthy people or that foods with a low glycemic effect promote weight loss.7 a review of the evidence thus far concludes that the ideal long-term study has not yet been conducted.8 most importantly, insulin is critical to maintaining health, as any person with type 1 diabetes can attest. -insulin causes prob- lems only when a person develops insulin resistance that is, when the body s cells do not respond to the large quantities of in- sulin that the pancreas continues to pump out in an effort to get a response. -insulin resistance is a major health problem but it is not caused by carbohydrate, or by protein, or by fat. -it results from being overweight. -when a person loses weight, insulin re- sponse improves. -the latest and greatest weight-loss diet again 317 table h9-2 popular diets compared diet major premise promoted strong point(s) weak point(s) high carbohydrate, low-fat ornish diet by strictly limiting fat (both animal and vegetable), you eat fewer kcalories without eating less food. -pritikin program by eating low-fat, mainly plant-based foods, you can eat more food and still feel satisfied. -low-carbohydrate, high protein atkins diet people are overweight or obese because they have metabolic imbalances caused by eating too many carbohydrates; by restricting carbohydrates, these imbalances can be corrected. -you can lose weight without lowering kcalorie intake. -low-carbohydrate zone diet eating the correct proportions of car- bohydrates, fat, and protein leads to hormonal balance, weight loss, disease prevention, and increased vitality. -carbohydrate-modified south beach diet the ultimate weight solution diet eating good carbohdrates such as vegetables, whole-wheat pastas, and brown rice will maintain satiety and resist cravings for bad carbohydrates such as white rice and potatoes. -foods that require great effort to prepare and eat are nutrient-dense; eating these kinds of foods (raw vegetables, vegetable soups, whole grains, beans, meats, poultry, and fish) will lead to weight loss. -foods that take little effort to prepare and eat provide excess kcalories relative to nutrients; eating these kinds of foods (fast foods, puddings, high- kcalorie convenience foods, processed foods) leads to uncontrolled eating and weight gain. -high-fiber, low-fat foods in this so little fat that essential fatty acids plan can lower blood cholesterol and blood pressure. -no food group is completely eliminated in this high-fiber, low-fat diet program. -some use of foods rich in omega-3 fatty acids are encouraged. -may be lacking. -limits fish, nuts, and olive oil which may protect against heart disease. -for some people, very low-fat diets may be unsatisfying and therefore difficult to adhere to. -quick, short-term weight restricts carbohydrates to a level that loss is achieved. -induces ketosis. -ketosis can cause nausea, light- headedness, and fatigue. -ketosis can worsen existing medical problems such as kidney disease. -a diet high in fat such as atkins can increase the risk of heart disease and some cancers. -promotes weight loss because the diet is rigid, restrictive, and complicated, making it difficult for most people to follow accurately. -the overblown health claims of the diet s proponents are based on misinterpreted science and remain unsubstantiated. -starchy carbohydrates and all fruits are completely excluded during the first two weeks. -confusing as to exactly what to eat or how much. -it is a low-kcalorie diet. -encourages consumption of vegetables, lean meats, and fish, and the use of unsaturated oils when cooking. -restricts fatty meats and cheeses as well as sweets. -encourages consumption of lean meats and fish; whole grains; vegetables; fruit; and low-fat milk, yogurt, and cheese. -restricts fatty meats and cheeses as well as sweets. -encourages exercise. -metabolic type eat right 4 your type your blood type determines which foods you should eat or not eat. -none food groups or individual foods are excluded, depending on blood type. -no scientific data on the relationship between blood type and food choices. -318 highlight 9 another distortion of the facts is the claim that high-protein foods expend more energy. -as chapter 8 mentioned, the thermic effect of food for protein is higher than for carbohydrate or fat, but the increase is still insignificant perhaps the equivalent of two pounds per year, at most. -if low-carbohydrate, high-protein diets were as successful as some people claim, then consumers who tried them would lose weight, and their obesity problems would be solved. -but this is not the case. -similarly, if high-protein diets were as worthless as others claim, then consumers would eventually stop pursuing them. -clearly, this is not happening either. -these diets have enough going for them that they work for some people at least for a short time, but they fail to produce long-lasting results for most people. -studies report that people following high-protein, low-carbohydrate diets do lose weight.9 in fact, they lose more than people following conventional high-carbohydrate, low-fat diets but only for the first six months. -their later gains make up the difference, so total weight loss is no different after one year.10 the following sections examine some of the apparent achieve- ments and shortcomings of high-protein diets.11 the diet s achievements with over half of our nation s adults overweight and many more concerned about their weight, the market for a weight-loss book, product, or program is huge (no pun intended). -americans spend an estimated $33 billion a year on weight-loss books and prod- ucts. -even a plan that offers only minimal weight-loss success eas- ily attracts a following. -carbohydrate-modified and high-protein, low-carbohydrate diet plans offer a little success to some people for a short time. -here s why. -don t count kcalories who wants to count kcalories? -even experienced dieters find count- ing kcalories burdensome, not to mention timeworn. -they want a new, easy way to lose weight, and high-protein diet plans seem to of- fer this boon. -but, though these diets often claim to disregard kcalo- ries, their design typically ensures a low energy intake. -most of the sample menu plans provided by these diets, especially in the early stages, are designed to deliver an average of 1200 kcalories a day. -even when counting kcalories is truly not necessary, the total for these diets tends to be low simply because food intake is so limited. -without its refried beans, tortilla wrapping, and chopped vegetables, a burrito is reduced to a pile of ground beef. -without the baked potato, there s no need for butter and sour cream. -weight loss occurs because of the low energy intake not the proportion of energy nutrients.12 success, then, depends on the restricted intake, not on protein s magical powers or carbohy- drate s evil forces. -this is an important point. -any diet can pro- duce weight loss, at least temporarily, if intake is restricted. -the real value of a diet is determined by its ability to maintain weight loss and support good health over the long term. -the goal is not simply weight loss, but health gains and whether carbohydrate- modified or high-protein, low-carbohydrate diets can support op- timal health over time remains unknown. -satisfy hunger protein may promote weight loss by providing satiety.13 as chap- ter 8 mentioned, of the three energy-yielding nutrients, protein is the most satiating. -high-protein meals suppress hunger and de- lay the start of the next meal. -furthermore, people tend to eat less after a high-protein meal than after a low-protein one. -in one study, when protein intake increased from 15 percent of total en- ergy to 30 percent but carbohydrate was held constant at 50 per- cent of total energy, people decreased their energy intakes and lost body weight and body fat.14 this research suggests that less emphasis should be placed on carbohydrate restriction. -in real-life situations, there is a strong association between a person s protein intake and bmi the higher the intake, the higher the bmi.15 this association remains apparent even after adjusting for energy intake and physical activity. -all meals whether designed for weight loss or not should include enough protein to satisfy hunger, but not so much as to contribute to weight gain. -follow a plan most people need specific instructions and examples to make di- etary changes. -popular diets offer dieters a plan. -the user doesn t have to decide what foods to eat, how to prepare them, or how much to eat. -unfortunately, these instructions only serve short- term weight-loss needs. -they do not provide for long-term changes in lifestyle that will support weight maintenance or health goals. -the success of any weight-loss diet depends on the person adopting the plan and sticking with it. -people who prefer the high-protein, low-carbohydrate diet over the high-carbohydrate, low-fat diet may have more success at sticking with it. -again, weight loss occurs because of the duration of a low-kcalorie plan not the proportion of energy nutrients.16 limit choices diets that omit hundreds of foods and several food groups limit a person s options and lack variety. -chapter 2 praised variety as a valuable way to ensure an adequate intake of nutrients, but vari- ety also entices people to eat more food and gain more weight. -without variety, some people lose interest in eating, which further reduces energy intake. -even if the allowed foods are favorites, eat- ing the same foods week after week can become monotonous. -the diet s shortcomings most of the foods that fad diets promote are healthy foods lean meats, fat-free or low-fat milk and yogurt, vegetables, whole grains, beans, and fruit. -the dietary guidelines for americans 2005 encourage consumers to eat the same foods. -the dietary guide- lines also advise consumers to eat less saturated fat, however, and some carbohydrate-restricted or carbohydrate-modified diets can be high in saturated fat. -like some of the carbohydrate-modified diets, the dietary guidelines also encourage people to eat a diet high in fiber-rich carbohydrate foods. -fad diet claims that people lose weight because they switch from eating bad carbohy- drates to eating good ones, however, are misleading; in truth, people lose weight on these diets because they are eating fewer kcalories not because they are eating different kinds of kcalories. -still, people who have followed carbohydrate-restricted or carbo- hydrate-modified diet plans for several months have lost weight. -can these diets be harmful? -too much fat some fad diets focus so intently on promoting protein and curb- ing carbohydrate that they fail to account for the fat that accom- panies many high-protein foods. -a breakfast of bacon and eggs, lunch of ham and cheese, and dinner of barbecued short ribs would provide 100 grams of protein and 121 grams of fat! -yet this day s meals, even with a snack of peanuts, provide only 1600 kcalories. -without careful selection, protein-rich diets can be ex- traordinarily high in saturated fat and cholesterol dietary factors that raise ldl cholesterol and the risks for heart disease. -overall, studies report that people following high-protein, low- carbohydrate diets have little or no change in blood pressure or blood lipids risk factors for heart disease.17 some researchers spec- ulate that the weight loss that occurs on these diets offsets the ad- verse effects of a diet high in saturated fat and low in fruits and vegetables.18 others point out that different sources of protein have different effects on risk factors for heart disease.19 for example, the effects of white meat from chicken or fish differ from those of red meat. -diets containing large amounts of red meat appear to in- crease the risk of heart disease. -in contrast, replacing animal sources of protein with plant sources of protein may benefit health. -too much protein moderation has been a recurring theme throughout this text, with recommendations to get enough, but not too much of any- thing, and cautions that too much can be as harmful as too little. -too much protein can contribute to weight gain just as too much carbohydrate or fat can. -as mentioned earlier, protein intake is positively associated with bmi.20 the dri committee did not es- tablish an upper level for protein, but it does recognize that high- protein diets have been implicated in chronic diseases such as osteoporosis, kidney stones and kidney disease, some cancers, heart disease, and obesity.21 health recommendations typically advise a protein intake of 50 to 100 grams per day and within the range of 10 to 35 percent of energy intake.22 this range allows for flexibility without risk of harm. -by comparison, popular high-pro- tein diets suggest a protein intake of 70 to 160 grams per day, representing 25 to 65 percent of energy intake.23 guidelines from the dri committee include higher protein in- takes (10 to 35 percent of total energy) than recommended pre- viously, but long-term studies of high-protein intakes are needed to ascertain the health consequences of such diets. -one such study is currently under way: the diogenes (diet, obesity, and genes) project is examining the interactions among a high di- etary protein intake, the glycemic effect of foods, and genetic and behavioral factors in preventing weight gain and regain.24 the the latest and greatest weight-loss diet again 319 study focuses on about 700 overweight or obese adults and their children in eight different countries across europe and may in- volve the united states as well. -too little everything else the quality of the diet suffers when carbohydrates are restricted.25 without fruits, vegetables, and whole grains, high-protein diets lack not only carbohydrate, but fiber, vitamins, minerals, and phyto- chemicals as well all dietary factors protective against disease.26 to help shore up some of these inadequacies, fad diets often rec- ommend a dietary supplement. -conveniently, many of the compa- nies selling fad diets also peddle these supplements. -but as highlights 10 and 11 explain, foods offer many more health bene- fits than any supplement can provide. -quite simply, if the diet is in- adequate, it needs to be improved, not supplemented. -the body s perspective when a person consumes a low-carbohydrate diet, a metabolism similar to that of fasting prevails. -(see chapter 7 for a review of fast- ing.) -with little dietary carbohydrate coming in, the body uses its glycogen stores to provide glucose for the cells of the brain, nerves, and blood. -once the body depletes its glycogen reserves, it begins making glucose from the amino acids of protein (gluconeogenesis). -a low-carbohydrate diet may provide abundant protein from food, but the body still uses some protein from body tissues. -dieters can know glycogen depletion has occurred and gluco- neogenesis has begun by monitoring their urine. -whenever glycogen or protein is broken down, water is released and urine production increases. -low-carbohydrate diets also induce ketosis, and ketones can be detected in the urine. -ketones form whenever glucose is lacking and fat breakdown is incomplete. -many fad diets regard ketosis as the key to losing weight, but studies comparing weight-loss diets find no relation between ke- tosis and weight loss.27 people in ketosis may experience a loss of s e g a m i y t t e g / c s i d o t o h p the wise consumer distinguishes between loss of fat and loss of weight. -320 highlight 9 adverse side effects of low-carbohydrate, table h9-3 ketogenic diets nausea fatigue (especially if physically active) constipation low blood pressure elevated uric acid (which may exacerbate kidney disease and cause inflammation of the joints in those predisposed to gout) stale, foul taste in the mouth (bad breath) in pregnant women, fetal harm and stillbirth appetite and a dramatic weight loss within the first few days. -they should know that much of this weight loss reflects the loss of glycogen and protein together with large quantities of body fluids and important minerals.28 they need to appreciate the difference between loss of fat and loss of weight. -fat losses on ketogenic di- ets are no greater than on other diets providing the same num- ber of kcalories. -once the dieter returns to well-balanced meals that provide adequate energy, carbohydrate, fat, protein, vita- mins, and minerals, the body avidly retains these needed nutri- ents. -the weight will return, quite often to a level higher than the starting point. -table h9-3 lists other consequences of a keto- genic diet. -table h9-4 offers guidelines for identifying fad diets and other weight-loss scams; it includes the hallmarks of a reasonable weight-loss program as well. -diets that overemphasize protein and fall short on carbohydrate may not harm healthy people if used for only a little while, but they cannot support optimal health for long. -chapter 9 includes reasonable approaches to weight management and concludes that the ideal diet is one you can live with for the rest of your life. -keep that criterion in mind when you evaluate the next latest and greatest weight-loss diet that comes along. -table h9-4 guidelines for identifying fad diets and other weight-loss scams fad diets and weight-loss scams healthy diet guidelines 1. they promise dramatic, rapid weight loss. -2. they promote diets that are nutritionally unbalanced or extremely low 1. weight loss should be gradual and not exceed 2 pounds per week. -2. diets should provide: in kcalories. -a reasonable number of kcalories (not fewer than 1000 kcalories per day for women and 1200 kcalories per day for men) enough, but not too much, protein (between the rda and twice the rda) enough, but not too much, fat (between 20 and 35% of daily energy intake from fat) enough carbohydrates to spare protein and prevent ketosis (at least 100 grams per day) and 20 to 30 grams of fiber from food sources a balanced assortment of vitamins and minerals from a variety of foods from each of the food groups at least 1 liter (about 1 quart) of water daily or 1 milliliter per kcalorie daily whichever is more. -3. they use liquid formulas rather than foods. -3. foods should accommodate a person s ethnic background, taste prefer- ences, and financial means. -4. they attempt to make clients dependent upon special foods or devices. -4. programs should teach clients how to make good choices from the con- 5. they fail to encourage permanent, realistic lifestyle changes. -ventional food supply. -5. programs should teach physical activity plans that involve spending at least 300 kcalories a day and behavior-modification strategies that help to correct poor eating habits. -6. they misrepresent salespeople as counselors supposedly qualified to 6. even if adequately trained, such counselors would still be objection- give guidance in nutrition and/or general health. -able because of the obvious conflict of interest that exists when providers profit directly from products they recommend and sell. -7. they collect large sums of money at the start or require that clients sign 7. programs should be reasonably priced and run on a pay-as-you-go basis. -contracts for expensive, long-term programs. -8. they fail to inform clients of the risks associated with weight loss in gen- 8. they should provide information about dropout rates, the long-term eral or the specific program being promoted. -success of their clients, and possible diet side effects. -9. they promote unproven or spurious weight-loss aids such as human chorionic gonadotropin hormone (hcg), starch blockers, diuretics, sauna belts, body wraps, passive exercise, ear stapling, acupuncture, electric muscle-stimulating (ems) devices, spirulina, amino acid supple- ments (e.g. -arginine, ornithine), glucomannan, methylcellulose (a bulk- ing agent ), unique ingredients, and so forth. -9. they should focus on nutrient-rich foods and regular excercise. -10. they fail to provide for weight maintenance after the program ends. -10. they should provide a plan for weight maintenance after successful weight loss. -sources: adapted from american college of sports medicine, acsm s guidelines for exercise testing and prescription (baltimore: williams & wilkins, 1995), pp. -218 219; j. t. dwyer, treat- ment of obesity: conventional programs and fad diets, in obesity, ed. -p. bj rntorp and b.n. -brodoff (philadelphia: j.b. lippincott, 1992), p. 668; national council against health fraud newsletter, march/april 1987, national council against health fraud, inc. the latest and greatest weight-loss diet again 321 nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 9, then to highlights nutrition on the net. -search for the great nutrition debate at the usda s site: www.usda.gov references 1. c. l. ogden and coauthors, prevalence of overweight and obesity in the united states, 1999-2004, journal of the american medical association 295 (2006): 1549-1555. -2. p. chanmugam and coauthors, did fat intake in the 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to follow a low-glycaemic index diet? -yes, obesity reviews 3 (2002): 235-243. -6. f. x. pi-sunyer, glycemic index and disease, american journal of clinical nutrition 76 (2002): 290s-298s. -7. pi-sunyer, 2002. -8. a. g. pittas and s. b. roberts, dietary compo- sition and weight loss: can we individualize dietary prescriptions according to insulin sensitivity or secretion status? -nutrition reviews 64 (2006): 435-448; raben, 2002. -9. a. astrup, t. m. larsen, and a. harper, atkins and other low-carbohydrate diets: hoax or an effective tool for weight loss? -the lancet 364 (2004): 897-899; e. c. west- man and coauthors, effect of 6-month adherence to a very low carbohydrate diet program, american journal of medicine 113 (2002): 30-36. -10. l. stern and coauthors, the effects of low- carbohydrate versus conventional weight loss diets in severely obese adults: one-year follow-up of a randomized trial, annals of internal medicine 140 (2004): 778-785; g. d. foster and coauthors, a randomized 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high-carbohydrate/low-fat diet, journal of the american dietetic associa- tion 105 (2005): 1433-1437. -14. d. s. weigle and coauthors, a high-protein diet induces sustained reductions in ap- petite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concen- trations, american journal of clinical nutri- tion 82 (2005): 41-48. -15. a. trichopoulou and coauthors, lipid, protein and carbohydrate intake in relation to body mass index, european journal of clinical nutrition 56 (2002): 37-43. -16. bravata and coauthors, 2003. -17. bravata and coauthors, 2003. -18. foster and coauthors, 2003. -19. f. b. hu, protein, body weight, and cardio- vascular health, american journal of clinical nutrition 82 (2005): 242s-247s. -20. a. trichopoulou and coauthors, lipid, protein and carbohydrate intake in relation to body mass index, european journal of clinical nutrition 56 (2002): 37-43. -21. committee on dietary reference intakes, dietary reference intakes for energy, carbohy- drate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (washington, d.c.: national academies press, 2002/2005). -22. committee on dietary reference intakes, 2002/2005; s. t. st. jeor and coauthors, dietary protein and weight reduction: a statement for healthcare professionals from the nutrition committee of the council on nutrition, physical activity, and metabolism of the american heart association, circula- tion 104 (2001): 1869-1874. -23. st. jeor and coauthors, 2001. -24. w. h. m. saris and a. harper, diogenes: a multidisciplinary offensive focused on the obesity epidemic, obesity reviews 6 (2005): 175-176. -25. l. s. greene-finestone and coauthors, adolescents low-carbohydrate-density diets are related to poorer dietary intakes, journal of the american dietetic association 105 (2005): 1783-1788; e. t. kennedy and coau- thors, popular diets: correlation to health, nutrition, and obesity, journal of the ameri- can dietetic association 101 (2001): 411-420. -26. w. cunningham and d. hyson, the skinny on high-protein, low-carbohydrate diets, preventive cardiology 9 (2006): 166-171. -27. m. d. coleman and s. m. nickols-richard- son, urinary ketones reflect serum ketone concentration but do not relate weight loss in overweight premenopausal women following a low-carbohydrate/high-protein diet, journal of the american dietetic associa- tion 105 (2005): 608-611; foster and coau- thors, 2003. -28. st. jeor and coauthors, 2001. michael rosenfeld/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow figure 10-1: animated! -coenzyme action figure 10-13: animated! -metabolic pathways involving b vitamins how to: practice problems nutrition portfolio journal if you were playing a word game and your partner said vitamins, how would you respond? -if pills and supplements immediately come to mind, you may be missing the main message of the vitamin story that hundreds of foods deliver over a dozen vitamins that participate in thousands of activities throughout your body. -quite simply, foods supply vitamins to support all that you are and all that you do and supplements of any one of them, or even a nutrition calculations: practice problems combination of them, can t compete with foods in keeping you healthy. -the water soluble vitamins: b vitamins and vitamin c earlier chapters focused on the energy-yielding nutrients, which play lead- ing roles in the body. -the vitamins and minerals are their supporting cast. -this chapter begins with an overview of the vitamins and then examines each of the water-soluble vitamins and a nonvitamin relative named choline; the next chapter features the fat-soluble vitamins. -chapters 12 and 13 present the minerals. -the vitamins an overview researchers first recognized that foods contain substances that are vital to life in the early 1900s. -since then, the world of vitamins has opened up dramatically. -the vitamins are powerful substances, as their absence attests. -vitamin a deficiency can cause blindness; a lack of the b vitamin niacin can cause dementia; and a lack of vitamin d can retard bone growth. -the consequences of deficiencies are so dire, and the effects of restoring the needed vitamins so dramatic, that people spend bil- lions of dollars every year in the belief that vitamin pills will cure a host of ailments (see highlight 10). -vitamins certainly support sound nutritional health, but they do not cure all ills. -furthermore, vitamin supplements do not offer the many benefits that come from vitamin-rich foods. -the presence of the vitamins also attests to their power. -the b vitamin folate helps to prevent birth defects. -vitamin c seems to protect against certain types of cancer. -similarly, vitamin e seems to help protect against some facets of cardiovascular dis- ease. -as you will see, the vitamins roles in supporting optimal health extend far be- yond preventing deficiency diseases. -in fact, some of the credit given to low-fat diets in preventing disease actually belongs to the vitamins found in vegetables, fruits, and whole grains (see highlight 11 for more on vitamins in disease prevention). -the vitamins differ from carbohydrates, fats, and proteins in the following ways: structure. -vitamins are individual units; they are not linked together (as are molecules of glucose or amino acids). -appendix c presents the chemical structure for each of the vitamins. -function. -vitamins do not yield usable energy when broken down; they assist the enzymes that release energy from carbohydrates, fats, and proteins. -c h a p t e r 10 chapter outline the vitamins an overview the b vitamins as individuals thiamin riboflavin niacin biotin pantothentic acid vitamin b6 folate vitamin b12 non-b vitamins the b vitamins in concert b vitamin roles b vitamin deficiencies b vitamin toxicities b vitamin food sources vitamin c vitamin c roles vitamin c recommendations vitamin c defi- ciency vitamin c toxicity vitamin c food sources highlight 10 vitamin and mineral supplements reminder: the vitamins are organic, essen- tial nutrients required in tiny amounts to perform specific functions that promote growth, reproduction, or the maintenance of health and life. -vita = life amine = containing nitrogen (the first vitamins discovered contained nitrogen) 1 g = 1000 mg food contents. -the amounts of vitamins people ingest daily from foods and the amounts they require are measured in micrograms ( g) or milligrams (mg), rather than grams (g). -1 mg = 1000 g for perspective, a dollar bill weighs about 1 g. 323 324 chapter 10 to minimize vitamin losses, wrap cut fruits and vegetables or store them in airtight containers. -water-soluble vitamins: b vitamins: thiamin riboflavin niacin biotin pantothenic acid vitamin b6 folate vitamin b12 vitamin c fat-soluble vitamins: vitamin a vitamin d vitamin e vitamin k bioavailability: the rate at and the extent to which a nutrient is absorbed and used. -precursors: substances that precede others; with regard to vitamins, compounds that can be converted into active vitamins; also known as provitamins. -the vitamins are similar to the energy-yielding nutrients, though, in that they are vital to life, organic, and available from foods. -bioavailability the amount of vitamins available from foods depends not only on the quantity provided by a food but also on the amount absorbed and used by the body referred to as the vitamins bioavailability. -the quantity of vitamins in a food can be determined relatively easily. -researchers analyze foods to determine their vitamin contents and publish the results in tables of food composition such as appendix h. determining the bioavailability of a vitamin is a more complex task because it depends on many factors, including: efficiency of digestion and time of transit through the gi tract previous nutrient intake and nutrition status . -c n i , s o i d u t s a r a l o p other foods consumed at the same time (chapters 10 13 describe factors that inhibit or enhance the absorption of individual vitamins and minerals.) -method of food preparation (raw, cooked, or processed) source of the nutrient (synthetic, fortified, or naturally occurring) experts consider these factors when estimating recommended intakes. -precursors some of the vitamins are available from foods in inactive forms known as precursors, or provitamins. -once inside the body, the precursor is con- verted to an active form of the vitamin. -thus, in measuring a person s vitamin in- take, it is important to count both the amount of the active vitamin and the potential amount available from its precursors. -the discussions and summary ta- bles throughout this chapter and the next indicate which vitamins have precursors. -organic nature being organic, vitamins can be destroyed and left unable to per- form their duties. -therefore, they must be handled with care during storage and in cooking. -prolonged heating may destroy much of the thiamin in food. -because ri- boflavin can be destroyed by the ultraviolet rays of the sun or by fluorescent light, foods stored in transparent glass containers are most likely to lose riboflavin. -oxygen destroys vitamin c, so losses occur when foods are cut, processed, and stored; these losses may be enough to reduce its action in the body.1 table 10-1 summarizes ways to minimize nutrient losses in the kitchen, and chapter 19 provides more details. -solubility as you may recall, carbohydrates and proteins are hydrophilic and lipids are hydrophobic. -the vitamins divide along the same lines the hydrophilic, water-soluble ones are the eight b vitamins and vitamin c; the hydrophobic, fat- soluble ones are vitamins a, d, e, and k. as each vitamin was discovered, it was given a name and sometimes a letter and number as well. -many of the water- soluble vitamins have multiple names, which has led to some confusion. -the mar- gin lists the standard names, and summary tables throughout this chapter provide the common alternative names. -solubility is apparent in the food sources of the different vitamins, and it affects their absorption, transport, storage, and excretion by the body. -the water-soluble vitamins are found in the watery compartments of foods; the fat-soluble vitamins table 10-1 minimizing nutrient losses to slow the degradation of vitamins, refrigerate (most) fruits and vegetables. -to minimize the oxidation of vitamins, store fruits and vegetables that have been cut in airtight wrappers, and store juices that have been opened in closed containers (and refrigerate them). -to prevent losses during washing, rinse fruits and vegetables before cutting. -to minimize losses during cooking, use a microwave oven or steam vegetables in a small amount of water. -add vegetables after water has come to a boil. -use the cooking water in mixed dishes such as casseroles and soups. -avoid high temperatures and long cooking times. -the water soluble vitamins: b vitamins and vitamin c 325 usually occur together in the fats and oils of foods. -on being absorbed, the water- soluble vitamins move directly into the blood. -like fats, however, the fat-soluble vita- mins must first enter the lymph, then the blood. -once in the blood, many of the wa- ter-soluble vitamins travel freely, whereas many of the fat-soluble vitamins require protein carriers for transport. -upon reaching the cells, water-soluble vitamins freely circulate in the water-filled compartments of the body, but fat-soluble vitamins are held in fatty tissues and the liver until needed. -the kidneys, monitoring the blood that flows through them, detect and remove small excesses of water-soluble vitamins (large excesses, however, may overwhelm the system, creating adverse effects). -fat- soluble vitamins tend to remain in fat-storage sites in the body rather than being ex- creted, and so are more likely to reach toxic levels when consumed in excess. -because the body stores fat-soluble vitamins, they can be eaten in large amounts once in a while and still meet the body s needs over time. -water-soluble vitamins are retained for varying periods in the body. -although a single day s omission from the diet does not bring on a deficiency, the water-soluble vitamins must still be eaten more regularly than the fat-soluble vitamins. -toxicity knowledge about some of the amazing roles of vitamins has prompted many people to assume that more is better and take vitamin supplements. -but just as an inadequate intake can cause harm, so can an excessive intake. -even some of the water-soluble vitamins have adverse effects when taken in large doses. -that a vitamin can be both essential and harmful may seem surprising, but the same is true of most nutrients. -the effects of every substance depend on its dose, and this is one reason consumers should not self-prescribe supplements for their ailments. -see the how to below for a perspective on doses. -the committee on dietary reference intakes (dri) addresses the possibility of adverse effects from high doses of nutrients by establishing tolerable upper intake levels. -an upper level defines the highest amount of a nutrient that is likely not to cause harm for most healthy people when consumed daily. -the risk of harm in- creases as intakes rise above the upper level. -of the nutrients discussed in this chapter, niacin, vitamin b6, folate, choline, and vitamin c have upper levels, and these values are presented in their respective summary tables. -data are lacking to establish upper levels for the remaining b vitamins, but this does not mean that how to understand dose levels and effects a substance may have a beneficial or harm- ful effect, but a critical thinker would not conclude that the substance itself was bene- ficial or harmful without first asking what dose was used. -the accompanying figure shows three possible relationships between dose levels and effects. -the third diagram represents the situation with nutrients more is better up to a point, but beyond that point, still more can be harmful. -r e t t e b r e t t e b r e t t e b more more more as you progress in the direction of more, the effect gets better and better, with no end in sight (real life is seldom, if ever, like this). -as you progress in the direction of more, the effect reaches a maximum and then a plateau, becoming no better with higher doses. -as you progress in the direction of more, the effect reaches an optimum at some intermediate dose and then declines, showing that more is better up to a point and then harmful. -that too much can be as harmful as too little represents the situation with most nutrients. -326 chapter 10 excessively high intakes would be without risk. -(the inside front cover pages pres- ent upper levels for the vitamins and minerals.) -in summary the vitamins are essential nutrients needed in tiny amounts in the diet both to prevent deficiency diseases and to support optimal health. -the water- soluble vitamins are the b vitamins and vitamin c; the fat-soluble vitamins are vitamins a, d, e, and k. the accompanying table summarizes the differ- ences between the water-soluble and fat-soluble vitamins. -water-soluble vitamins: b vitamins and vitamin c fat-soluble vitamins: vitamins a, d, e, and k absorption directly into the blood transport storage excretion toxicity travel freely circulate freely in water-filled parts of the body kidneys detect and remove excess in urine first into the lymph, then the blood many require protein carriers stored in the cells associated with fat less readily excreted; tend to remain in fat-storage sites possible to reach toxic levels when consumed from supplements likely to reach toxic levels when consumed from supplements reminder: a coenzyme is a small organic molecule that associates closely with cer- tain enzymes; many b vitamins form an integral part of coenzymes. -requirements needed in frequent doses (perhaps 1 to 3 days) needed in periodic doses (perhaps weeks or even months) note: exceptions occur, but these differences between the water-soluble and fat-soluble vitamins are valid generalizations. -the discussion of b vitamins that follows begins with a brief description of each of them, then offers a look at the ways they work together. -thus, a preview of the in- dividual vitamins is followed by a survey of how they work together, in concert. -the b vitamins as individuals despite supplement advertisements that claim otherwise, the vitamins do not pro- vide the body with fuel for energy. -it is true, though, that without b vitamins the body would lack energy. -the energy-yielding nutrients carbohydrate, fat, and pro- tein are used for fuel; the b vitamins help the body to use that fuel. -several of the b vitamins thiamin, riboflavin, niacin, pantothenic acid, and biotin form part of the coenzymes that assist certain enzymes in the release of energy from carbohy- drate, fat, and protein. -other b vitamins play other indispensable roles in metabo- lism. -vitamin b6 assists enzymes that metabolize amino acids; folate and vitamin b12 help cells to multiply. -among these cells are the red blood cells and the cells lin- ing the gi tract cells that deliver energy to all the others. -the vitamin portion of a coenzyme allows a chemical reaction to occur; the re- maining portion of the coenzyme binds to the enzyme. -without its coenzyme, an enzyme cannot function. -thus symptoms of b vitamin deficiencies directly reflect the disturbances of metabolism incurred by a lack of coenzymes. -figure 10-1 illus- trates coenzyme action. -the following sections describe individual b vitamins and note many coenzymes and metabolic pathways. -keep in mind that a later discussion assembles these pieces of information into a whole picture. -the following sections also present the recom- mendations, deficiency and toxicity symptoms, and food sources for each vitamin. -the recommendations for the b vitamins and vitamin c reflect the 1998 and 2000 dri, respectively.2 for thiamin, riboflavin, niacin, vitamin b6, folate, vitamin b12, and vitamin c, sufficient data were available to establish an rda; for biotin, pantothenic acid, and choline, an adequate intake (ai) was set; only niacin, vitamin b6, folate, choline, and vitamin c have tolerable upper intake levels. -these values appear in the summary tables and figures that follow and on the pages of the inside front cover. -the water soluble vitamins: b vitamins and vitamin c 327 figure 10-1 animated! -coenzyme action some vitamins form part of the coenzymes that enable enzymes either to synthesize compounds (as illustrated by the lower enzymes in this figure) or to dismantle compounds (as illustrated by the upper enzymes). -to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow enzyme active site compounds cd a b active site enzyme enzyme coenzyme vitamin b a cd vitamin coenzyme enzyme enzyme cd a b enzyme without coenzymes, compounds a, b, and cd don t respond to their enzymes. -with the coenzymes in place, compounds are attracted to their sites on the enzymes . -. -. -. -. -. -and the reactions proceed instantaneously. -the coenzymes often donate or accept electrons, atoms, or groups of atoms. -enzyme c d a b new products enzyme the reactions are completed with either the formation of a new product, ab, or the breaking apart of a compound into two new products, c and d, and the release of energy. -thiamin thiamin is the vitamin part of the coenzyme tpp (thiamin pyrophosphate), which assists in energy metabolism. -the tpp coenzyme participates in the conversion of pyruvate to acetyl coa (described in chapter 7). -the reaction removes one carbon from the 3-carbon pyruvate to make the 2-carbon acetyl coa and carbon dioxide (co2). -later, tpp participates in a similar step in the tca cycle where it helps con- vert a 5-carbon compound to a 4-carbon compound. -besides playing these pivotal roles in the energy metabolism of all cells, thiamin occupies a special site on the membranes of nerve cells. -consequently, processes in nerves and in their respond- ing tissues, the muscles, depend heavily on thiamin. -thiamin recommendations dietary recommendations are based primarily on thiamin s role in enzyme activity. -generally, thiamin needs will be met if a person eats enough food to meet energy needs if that energy comes from nutritious foods. -the average thiamin intake in the united states and canada meets or exceeds rec- ommendations. -thiamin deficiency and toxicity people who fail to eat enough food to meet en- ergy needs risk nutrient deficiencies, including thiamin deficiency. -inadequate thi- amin intakes have been reported among the nation s malnourished and homeless people. -similarly, people who derive most of their energy from empty-kcalorie items risk thiamin deficiency. -alcohol is a good example. -it contributes energy but pro- vides few, if any, nutrients and often displaces food. -in addition, alcohol impairs thi- amin absorption and enhances thiamin excretion in the urine, doubling the risk of deficiency. -an estimated four out of five alcoholics are thiamin deficient. -prolonged thiamin deficiency can result in the disease beriberi, which was first observed in indonesia when the custom of polishing rice became widespread.3 rice provided 80 percent of the energy intake of the people of that area, and the germ and bran of the rice grain was their principal source of thiamin. -when the germ and bran were removed in the preparation of white rice, beriberi spread like wildfire. -the symp- toms of beriberi include damage to the nervous system as well as to the heart and other muscles. -figure 10-2 presents one of the symptoms of beriberi. -no adverse effects have been associated with excesses of thiamin; no upper level has been determined. -severe thiamin deficiency in alcohol abusers is called the wernicke-korsakoff (ver-nee-key kore-sah-kof) syndrome. -symptoms include disorientation, loss of short-term memory, jerky eye movements, and staggering gait. -thiamin (thigh-ah-min): a b vitamin. -the coenzyme form is tpp (thiamin pyrophosphate). -beriberi: the thiamin-deficiency disease. -beri = weakness beriberi = i can t, i can t 328 chapter 10 thiamin-deficiency figure 10-2 symptom the edema of beriberi beriberi may be characterized as wet (referring to edema) or dry (with mus- cle wasting, but no edema). -physical examination confirms that this person has wet beriberi. -notice how the impres- sion of the physician s thumb remains on the leg. -thiamin food sources before examining figure 10-3, you may want to read the accompanying how to, which describes the many features found in this and similar figures in this chapter and the next three chapters. -when you look at fig- ure 10-3, notice that thiamin occurs in small quantities in many nutritious foods. -the long red bar near the bottom of the graph shows that meats in the pork fam- ily are exceptionally rich in thiamin. -yellow bars confirm that enriched grains are a reliable source of thiamin. -as mentioned earlier, prolonged cooking can destroy thiamin. -also, like other water-soluble vitamins, thiamin leaches into water when foods are boiled or blanched. -cooking methods that require little or no water such as steaming and microwave heating conserve thiamin and other water-soluble vitamins. -the ac- companying table (p. 329) summarizes thiamin s main functions, food sources, and deficiency symptoms. -riboflavin like thiamin, riboflavin serves as a coenzyme in many reactions, most notably in the release of energy from nutrients in all body cells. -the coenzyme forms of ri- boflavin are fmn (flavin mononucleotide) and fad (flavin adenine dinucleotide); both can accept and then donate two hydrogens (see figure 10-4, p. 330). -during en- ergy metabolism, fad picks up two hydrogens (with their electrons) from the tca cycle and delivers them to the electron transport chain (described in chapter 7). -o t o h p k c o t s l a c i d e m m o t s u c / b s m n figure 10-3 thiamin in selected foods see the how to section on the next page for more information on using this figure. -milligrams food serving size (kcalories) 0 0.25 0.50 0.75 1.00 1.25 bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice banana orange strawberries c shr 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 edded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 c (31 kcal) 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 c fresh (22 kcal) 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 c low-fat 2% (101 kcal) 1 2 c cooked (117 kcal) 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 c (76 kcal) 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: pork chop, lean 3 oz broiled (169 kcal) soy milk squash, acorn 1 c (81 kcal) 1 2 c baked (69 kcal) rda for men rda for women thiamin many different foods contribute some thiamin, but few are rich sources. -together, several servings of a variety of nutritious foods will help meet thiamin needs. -bread and cereal selections should be either whole grain or enriched. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie the water soluble vitamins: b vitamins and vitamin c 329 how to evaluate foods for their nutrient contributions figure 10-3 is the first of a series of figures in this and the next three chapters that present the vitamins and minerals in foods. -each figure presents the same 24 foods, which were selected to ensure a variety of choices representative of each of the food groups as suggested by the usda food guide. -for example, a bread, a cereal, and a pasta were chosen from the grain group. -the suggestion to include a variety of vegetables was also considered: dark green, leafy vegetables (broccoli); deep orange and yellow vegeta- bles (carrots); starchy vegetables (potatoes); legumes (pinto beans); and other vegetables (tomato juice). -the selection of fruits followed suggestions to use whole fruits (bananas); citrus fruits (oranges); melons (watermelon); and berries (strawberries). -items were se- lected from the milk and meat groups in a similar way. -in addition to the 24 foods that appear in all of the figures, three different foods were selected for each of the nutrients to add variety and often reflect excellent, and sometimes unusual, sources. -notice that the figures list the food, the serving size, and the food energy (kcalories) on the left. -the amount of the nutrient per serving is presented in the graph on the right along with the rda (or ai) for adults, so you can see how many servings would be needed to meet recommendations. -the colored bars show at a glance which food groups best provide a nutrient: yellow for breads and cereals; green for vegetables; purple for fruits; white for milk and milk prod- ucts; brown for legumes; and red for meat, fish, and poultry. -because the usda food guide mentions legumes with both the meat group and the vegetable group and because legumes are especially rich in many vitamins and minerals, they have been given their own color to highlight their nutrient contributions. -notice how the bar graphs shift in the various figures. -careful study of all of the figures taken together will confirm that variety is the key to nutrient adequacy. -another way to evaluate foods for their nutrient contributions is to consider their nutrient density (their thiamin per 100 kcalo- ries, for example). -quite often, vegetables rank higher on a nutrient-per-kcalorie list than they do on a nutrient-per-serving list (see p. 38 to review how to evaluate foods based on nutrient density). -the left column in the figure highlights about five foods that offer the best deal for your energy dollar (the kcalorie). -notice how many of them are vegetables. -realistically, people cannot eat for single nutrients. -fortunately, most foods deliver more than one nutrient, allowing people to combine foods into nourishing meals. -in summary thiamin other names deficiency disease beriberi (wet, with edema; dry, with muscle wasting) deficiency symptomsa enlarged heart, cardiac failure; muscular weakness; apathy, poor short-term memory, confusion, irritability; anorexia, weight loss toxicity symptoms none reported vitamin b1 rda men: 1.2 mg/day women: 1.1 mg/day chief functions in the body part of coenzyme tpp (thiamin pyrophosphate) used in energy metabolism significant sources whole-grain, fortified, or enriched grain products; moderate amounts in all nutritious food; pork easily destroyed by heat asevere thiamin deficiency is often related to heavy alcohol consumption with limited food consumption (wernicke- korsakoff syndrome). -riboflavin recommendations like thiamin s rda, riboflavin s rda is based primarily on its role in enzyme activity. -most people in the united states and canada meet or exceed riboflavin recommendations. -riboflavin deficiency and toxicity riboflavin deficiency most often accom- panies other nutrient deficiencies. -lack of the vitamin causes inflammation of the membranes of the mouth, skin, eyes, and gi tract. -excesses of riboflavin appear to cause no harm; no upper level has been established. -. -c n i s o i d u t s a r a l o p pork is the richest source of thiamin, but enriched or whole-grain products typically make the greatest contribution to a day s intake because of the quantities eaten. -legumes such as split peas are also valuable sources of thiamin. -riboflavin deficiency is called ariboflavi- nosis (ay-rye-boh-flay-vin-oh-sis). -a = not osis = condition riboflavin food sources the greatest contributions of riboflavin come from milk and milk products (see figure 10-5, p. 331). -whole-grain or enriched bread and cereal products are also valuable sources because of the quantities typically consumed. -riboflavin (rye-boh-flay-vin): a b vitamin. -the coenzyme forms are fmn (flavin mononucleotide) and fad (flavin adenine dinucleotide). -330 chapter 10 turn to p. 38 for a review of how to evalu- ate foods based on nutrient density (per kcalorie). -figure 10-4 riboflavin coenzyme, accepting and donating hydrogens this figure shows the chemical structure of the riboflavin portion of the coenzyme only; the remainder of the coenzyme structure is represented by dotted lines (see appendix c for the complete chemical structures of fad and fmn). -the reactive sites that accept and donate hydrogens are highlighted in white. -h3c h3c c c o c n c c n n c c nh c o h c c h h3c h3c c c h n n c c c c h c c h o c n h nh c o fad during the tca cycle, compounds release hydrogens, and the riboflavin coenzyme fad picks up two of them. -as it accepts two hydrogens, fad becomes fadh2. -fadh2 fadh2 carries the hydrogens to the electron transport chain. -at the end of the electron transport chain, the hydrogens are accepted by oxygen, creating water, and fadh2 becomes fad again. -for every fadh2 that passes through the electron transport chain, 2 atp are generated. -when riboflavin sources are ranked by nutrient density (per kcalorie), many dark green, leafy vegetables (such as broccoli, turnip greens, asparagus, and spinach) ap- pear high on the list. -vegans and others who don t use milk must rely on ample serv- ings of dark greens and enriched grains for riboflavin. -nutritional yeast is another good source. -ultraviolet light and irradiation destroy riboflavin. -for these reasons, milk is sold in cardboard or opaque plastic containers, and precautions are taken when vi- tamin d is added to milk by irradiation. -* in contrast, riboflavin is stable to heat, so cooking does not destroy it. -the following summary table lists riboflavin s chief functions, food sources, and deficiency symptoms. -* vitamin d can be added to milk by feeding cows irradiated yeast or by irradiating the milk itself. -in summary riboflavin other names vitamin b2 rda men: 1.3 mg/day women: 1.1 mg/day chief functions in the body part of coenzymes fmn (flavin mononucleotide) and fad (flavin adenine dinucleotide) used in energy metabolism significant sources milk products (yogurt, cheese); whole-grain, fortified, or enriched grain products; liver . -c n i s o i d u t s l a r a o p easily destroyed by ultraviolet light and irradiation deficiency disease ariboflavinosis (ay-rye-boh-flay-vin-oh-sis) deficiency symptoms sore throat; cracks and redness at corners of mouth;a painful, smooth, purplish red tongue;b inflammation characterized by skin lesions cov- ered with greasy scales toxicity symptoms none reported all of these foods are rich in riboflavin, but milk and milk products provide much of the riboflavin in the diets of most people. -acracks at the corners of the mouth are called angular stomatitis or cheilosis (kye-loh-sis or kee-loh-sis). -bsmoothness of the tongue is caused by loss of its surface structures and is termed glossitis (gloss-eye-tis). -the water soluble vitamins: b vitamins and vitamin c 331 figure 10-5 riboflavin in selected foods see the how to section on p. 329 for more information on using this figure. -milligrams food serving size (kcalories) 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice banana orange strawberries watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) c fr c cooked (99 kcal) 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 edded raw (24 kcal) c shr 1 medium baked w/skin (133 kcal) 3 4 c (31 kcal) 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 esh (22 kcal) 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 c (76 kcal) 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: liver 3 oz fried (184 kcal) rda for men rda for women riboflavin milk and milk products (white) are noted for their riboflavin; several servings are needed to meet recommendations. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie clams, canned mushrooms 3 oz (126 kcal) 1 2 c cooked (21 kcal) niacin the name niacin describes two chemical structures: nicotinic acid and nicoti- namide (also known as niacinamide). -the body can easily convert nicotinic acid to nicotinamide, which is the major form of niacin in the blood. -the two coenzyme forms of niacin, nad (nicotinamide adenine dinucleotide) and nadp (the phosphate form), participate in numerous metabolic reactions. -they are central in energy-transfer reactions, especially the metabolism of glucose, fat, and alcohol. -nad is similar to the riboflavin coenzymes in that it carries hydro- gens (and their electrons) during metabolic reactions, including the pathway from the tca cycle to the electron transport chain. -niacin recommendations niacin is unique among the b vitamins in that the body can make it from the amino acid tryptophan. -to make 1 milligram of niacin requires approximately 60 milligrams of dietary tryptophan. -for this reason, recom- mended intakes are stated in niacin equivalents (ne). -a food containing 1 mil- ligram of niacin and 60 milligrams of tryptophan provides the equivalent of 2 milligrams of niacin, or 2 niacin equivalents. -the rda for niacin allows for this con- version and is stated in niacin equivalents; average niacin intakes in the united states and canada exceed recommendations. -niacin deficiency the niacin-deficiency disease, pellagra, produces the symptoms of diarrhea, dermatitis, dementia, and eventually death (often called the four ds ). -1 ne = 1 mg niacin or 60 mg tryptophan niacin (nigh-a-sin): a b vitamin. -the coenzyme forms are nad (nicotinamide adenine dinucleotide) and nadp (the phosphate form of nad). -niacin can be eaten preformed or made in the body from its precursor, tryptophan, one of the amino acids. -niacin equivalents (ne): the amount of niacin present in food, including the niacin that can theoretically be made from its precursor, tryptophan, present in the food. -pellagra (pell-ay-gra): the niacin-deficiency disease. -pellis = skin agra = rough 332 chapter 10 figure 10-6 niacin-deficiency symptom the dermatitis of pellagra in the dermatitis of pellagra, the skin darkens and flakes away as if it were sunburned. -the protein- deficiency disease kwashiorkor also produces a flaky paint dermatitis, but the two are easily distinguished. -the dermatitis of pellagra is bilateral and symmetrical and occurs only on those parts of the body exposed to the sun. -. -c n i , s r e h c r a e s e r o t o h p / y r a s n a . -a . -m . -r d in the early 1900s, pellagra caused widespread misery and some 87,000 deaths in the u.s. south, where many people subsisted on a low-protein diet centered on corn. -this diet supplied neither enough niacin nor enough tryptophan. -at least 70 percent of the niacin in corn is bound to complex carbohydrates and small pep- tides, making it unavailable for absorption. -furthermore, corn is high in the amino acid leucine, which interferes with the trypto- phan-to-niacin conversion, thus further contributing to the devel- opment of pellagra. -figure 10-6 illustrates the dermatitis of pellagra. -pellagra was originally believed to be caused by an infection. -medical researchers spent many years and much effort searching for infectious microbes until they realized that the problem was not what was present in the food but what was absent from it. -that a disease such as pellagra could be caused by diet and not by germs was a groundbreaking discovery. -it contradicted com- monly held medical opinions that diseases were caused only by infectious agents. -by carefully following the scientific method (as described in chapter 1), researchers advanced the science of nutri- tion dramatically. -* niacin toxicity naturally occurring niacin from foods causes no harm, but large doses from supplements or drugs produce a va- riety of adverse effects, most notably niacin flush. -niacin flush occurs when nicotinic acid is taken in doses only three to four times the rda. -it dilates the capillaries and causes a tingling sensation that can be painful. -the nicotinamide form does not produce this effect nor does it lower blood cholesterol. -large doses of nicotinic acid have been used to help lower blood cholesterol and prevent heart disease. -such therapy must be closely monitored. -people with the following conditions may be particularly susceptible to the toxic effects of niacin: liver disease, diabetes, peptic ulcers, gout, irregular heartbeats, inflammatory bowel disease, migraine headaches, and alcoholism. -when a normal dose of a nutrient (levels commonly found in foods) provides a nor- mal blood concentration, the nutrient is having a physiological effect. -when a large dose (levels commonly available only from supplements) overwhelms some body sys- tem and acts like a drug, the nutrient is having a pharmacological effect. -physio = natural pharma = drug niacin food sources tables of food composition typically list pre- formed niacin only, but as mentioned, niacin can also be made in the body from the amino acid tryptophan. -dietary tryptophan could meet about half the daily niacin need for most people, but the average diet easily supplies enough preformed niacin. -the how to on p. 333 shows how to es- timate the total amount of niacin available from both tryptophan and pre- formed niacin in the diet. -figure 10-7 (p. 334) presents niacin in selected foods. -meat, poultry, legumes, and enriched and whole grains contribute about half the niacin people con- sume. -mushrooms, potatoes, and tomatoes are among the richest vegetable sources, and they can provide abundant niacin when eaten in generous amounts. -niacin is less vulnerable to losses during food preparation and storage than other water-soluble vitamins. -being fairly heat-resistant, niacin can withstand reasonable cooking times, but like other water-soluble vitamins, it will leach into cooking water. -the summary table includes food sources as well as niacin s various names, functions, and deficiency and toxicity symptoms. -niacin flush: a temporary burning, tingling, and itching sensation that occurs when a person takes a large dose of nicotinic acid; often accompanied by a headache and reddened face, arms, and chest. -* dr. joseph goldberger, a physician for the u.s. government, headed the investigations that deter- mined that pellagra was a dietary disorder, not an infectious disease. -he died several years before con- rad elevjhem discovered that a deficiency of niacin caused pellagra. -the water soluble vitamins: b vitamins and vitamin c 333 how to estimate niacin equivalents to estimate niacin equivalents: calculate total protein consumed pounds to kilograms if necessary, and then multiply by 0.8 g/kg: to practice estimating niacin requirements, log on to www.thomsonedu.com/thomsonnow, go to chap- ter 10, then go to how to. -(grams). -assuming that the rda amount of pro- tein will be used first to make body pro- tein, subtract the rda to obtain leftover protein available to make niacin (grams). -(actually, the rda pro- vides a generous protein allowance, so leftover protein may be even greater than this.) -about 1 gram of every 100 grams of high-quality protein is tryptophan, so divide by 100 to obtain the tryptophan in this leftover protein (grams). -multiply by 1000 to express this amount of tryptophan in milligrams. -divide by 60 to get niacin equivalents (milligrams). -finally, add the amount of preformed niacin obtained in the diet (milligrams). -for example, suppose that a 19-year- old woman who weighs 130 pounds consumes 75 grams of protein in a day. -to calculate her protein rda, first convert 130 lb (cid:2) 2.2 lb/kg (cid:3) 59 kg 59 kg (cid:4) 0.8 g/kg (cid:3) 47 g then determine her leftover protein by subtracting her rda from her intake: 75 g protein intake (cid:5) 47 g protein rda (cid:3) 28 g protein leftover next calculate the amount of tryptophan in this leftover protein: 28 g protein (cid:2) 100 (cid:3) 0.28 g tryptophan 0.28 g tryptophan (cid:4) 1000 (cid:3) 280 mg tryptophan then convert milligrams of tryptophan to niacin equivalents: 280 mg tryptophan (cid:2) 60 (cid:3) 4.7 mg ne to determine the total amount of niacin available from the diet, add the amount available from tryptophan (4.7 mg ne) to the amount of preformed niacin obtained from the diet. -in summary niacin other names significant sources nicotinic acid, nicotinamide, niacinamide, vitamin b3; precursor is dietary tryptophan (an amino acid) milk, eggs, meat, poultry, fish; whole-grain, fortified, and enriched grain products; nuts and all protein-containing foods rda men: 16 mg ne/day women: 14 mg ne/day upper level adults: 35 mg/day chief functions in the body part of coenzymes nad (nicotinamide adenine dinucleotide) and nadp (its phosphate form) used in energy metabolism deficiency disease pellagra deficiency symptoms diarrhea, abdominal pain, vomiting; inflamed, swollen, smooth, bright red tongue;a depres- sion, apathy, fatigue, loss of memory, headache; bilateral symmetrical rash on areas exposed to sunlight toxicity symptoms painful flush, hives, and rash ( niacin flush ); nausea and vomiting; liver damage, impaired glucose tolerance asmoothness of the tongue is caused by loss of its surface structures and is termed glossitis (gloss-eye-tis). -. -c n i , s o i d u t s a r a l o p protein-rich foods such as meat, fish, poultry, and peanut butter contribute much of the niacin in people s diets. -enriched breads and cereals and a few vegetables are also rich in niacin. -biotin biotin plays an important role in metabolism as a coenzyme that carries acti- vated carbon dioxide. -this role is critical in the tca cycle: biotin delivers a carbon biotin (by-oh-tin): a b vitamin that functions as a coenzyme in metabolism. -334 chapter 10 figure 10-7 niacin in selected foods see the how to section on p. 329 for more information on using this figure. -food serving size (kcalories) 0 2 4 6 8 10 12 14 16 18 20 milligrams c (31 kcal) c fresh (22 kcal) c cooked (99 kcal) bread, whole wheat cornflakes, fortified spaghetti pasta 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) tortilla, flour broccoli carrots potato tomato juice banana orange strawberries watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: liver peanuts mushrooms 3 oz fried (184 kcal) 1 oz roasted (165 kcal) 1 2 c cooked (21 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) c (76 kcal) rda for men rda for women niacin members of the meat group (red) are prominent niacin sources. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie reminder: gluconeogenesis is the synthesis of glucose from noncarbohydrate sources such as amino acids or glycerol. -the protein avidin (av-eh-din) in egg whites binds biotin. -avid = greedy to 3-carbon pyruvate, thus replenishing oxaloacetate, the 4-carbon compound needed to combine with acetyl coa to keep the tca cycle turning. -the biotin coen- zyme also participates in gluconeogenesis, fatty acid synthesis, and the break- down of certain fatty acids and amino acids. -recent research has uncovered roles for biotin in gene expression.4 biotin recommendations biotin is needed in very small amounts. -instead of an rda, an adequate intake (ai) has been determined. -biotin deficiency and toxicity biotin deficiencies rarely occur. -researchers can induce a biotin deficiency in animals or human beings by feeding them raw egg whites, which contain a protein that binds biotin and thus prevents its absorption. -biotin-deficiency symptoms include skin rash, hair loss, and neurological impair- ment. -more than two dozen egg whites must be consumed daily for several months to produce these effects, however, and the eggs have to be raw; cooking denatures the binding protein. -no adverse effects from high biotin intakes have been reported, but some research indicates that biotin supplementation damages dna.5 biotin does not have an upper level. -biotin food sources biotin is widespread in foods (including egg yolks), so eating a variety of foods protects against deficiencies. -some biotin is also synthesized by gi tract bacteria, but this amount may not contribute much to the biotin absorbed. -a review of biotin facts is provided in the summary table. -the water soluble vitamins: b vitamins and vitamin c 335 in summary biotin adequate intake (ai) deficiency symptoms adults: 30 g/day chief functions in the body part of a coenzyme used in energy metabo- lism, fat synthesis, amino acid metabolism, and glycogen synthesis significant sources widespread in foods; liver, egg yolks, soy- beans, fish, whole grains; also produced by gi bacteria depression, lethargy, hallucinations, numb or tingling sensation in the arms and legs; red, scaly rash around the eyes, nose, and mouth; hair loss toxicity symptoms none reported pantothenic acid pantothenic acid is part of the chemical structure of coenzyme a the same coa that forms acetyl coa, the crossroads compound in several metabolic path- ways, including the tca cycle. -(appendix c presents the chemical structures of these two molecules and shows that coenzyme a is made up in part of pan- tothenic acid.) -as such, it is involved in more than 100 different steps in the syn- thesis of lipids, neurotransmitters, steroid hormones, and hemoglobin. -pantothenic acid recommendations an adequate intake (ai) for pantothenic acid has been set. -it reflects the amount needed to replace daily losses. -pantothenic acid deficiency and toxicity pantothenic acid deficiency is rare. -its symptoms involve a general failure of all the body s systems and include fatigue, gi distress, and neurological disturbances. -the burning feet syndrome that af- fected prisoners of war in asia during world war ii is thought to have been caused by pantothenic acid deficiency. -no toxic effects have been reported, and no upper level has been established. -pantothenic acid food sources pantothenic acid is widespread in foods, and typical diets seem to provide adequate intakes. -beef, poultry, whole grains, pota- toes, tomatoes, and broccoli are particularly good sources. -losses of pantothenic acid during food production can be substantial because it is readily destroyed by the freezing, canning, and refining processes. -the following summary table pres- ents pantothenic acid facts. -in summary pantothenic acid adequate intake (ai) deficiency symptoms adults: 5 mg/day chief functions in the body part of coenzyme a, used in energy metabolism significant sources widespread in foods; chicken, beef, potatoes, oats, tomatoes, liver, egg yolk, broccoli, whole grains easily destroyed by food processing vomiting, nausea, stomach cramps; insomnia, fatigue, depression, irritability, restlessness, apathy; hypoglycemia, increased sensitivity to insulin; numbness, muscle cramps, inability to walk toxicity symptoms none reported pantothenic (pan-toe-then-ick) acid: a b vitamin. -the principal active form is part of coenzyme a, called coa throughout chapter 7. pantos = everywhere 336 chapter 10 reminder: serotonin is a neurotransmitter important in appetite control, sleep regula- tion, and sensory perception, among other roles; it is synthesized in the body from the amino acid tryptophan with the help of vitamin b6. -vitamin b6: a family of compounds pyridoxal, pyridoxine, and pyridoxamine. -the primary active coenzyme form is plp (pyridoxal phosphate). -antagonist: a competing factor that counteracts the action of another factor. -when a drug displaces a vitamin from its site of action, the drug renders the vitamin ineffective and thus acts as a vitamin antagonist. -carpal tunnel syndrome: a pinched nerve at the wrist, causing pain or numbness in the hand. -it is often caused by repetitive motion of the wrist. -vitamin b6 vitamin b6 occurs in three forms pyridoxal, pyridoxine, and pyridoxamine. -all three can be converted to the coenzyme plp (pyridoxal phosphate), which is active in amino acid metabolism. -because plp can transfer amino groups (nh2) from an amino acid to a keto acid, the body can make nonessential amino acids (review fig- ure 7-15, p. 226). -the ability to add and remove amino groups makes plp valuable in protein and urea metabolism as well. -the conversions of the amino acid trypto- phan to niacin or to the neurotransmitter serotonin also depend on plp as does the synthesis of heme (the nonprotein portion of hemoglobin), nucleic acids (such as dna and rna), and lecithin. -a surge of research in the last decade has revealed that vitamin b6 influences cognitive performance, immune function, and steroid hormone activity. -unlike other water-soluble vitamins, vitamin b6 is stored extensively in muscle tissue. -vitamin b6 recommendations because the vitamin b6 coenzymes play many roles in amino acid metabolism, previous rda were expressed in terms of protein in- takes; the current rda for vitamin b6, however, is not. -research does not support claims that large doses of vitamin b6 enhance muscle strength or physical en- durance. -as highlight 14 explains, vitamin supplements cannot compete with a nu- tritious diet and physical training. -vitamin b6 deficiency without adequate vitamin b6, synthesis of key neuro- transmitters diminishes, and abnormal compounds produced during tryptophan metabolism accumulate in the brain. -early symptoms of vitamin b6 deficiency in- clude depression and confusion; advanced symptoms include abnormal brain wave patterns and convulsions. -alcohol contributes to the destruction and loss of vitamin b6 from the body. -as highlight 7 described, when the body breaks down alcohol, it produces acetalde- hyde. -if allowed to accumulate, acetaldehyde dislodges the plp coenzyme from its enzymes; once loose, plp breaks down and is excreted. -low concentrations of plp increase the risk of heart disease.6 another drug that acts as a vitamin b6 antagonist is inh, a medication that inhibits the growth of the tuberculosis bacterium. -* this drug has saved countless lives, but as a vitamin b6 antagonist, inh binds and inactivates the vitamin, induc- ing a deficiency. -whenever inh is used to treat tuberculosis, vitamin b6 supple- ments must be given to protect against deficiency. -vitamin b6 toxicity the first major report of vitamin b6 toxicity appeared in the early 1980s. -until that time, everyone (including researchers and dietitians) believed that, like the other water-soluble vitamins, vitamin b6 could not reach toxic concen- trations in the body. -the report described neurological damage in people who had been taking more than 2 grams of vitamin b6 daily (20 times the current upper level of 100 milligrams per day) for two months or more. -some people have taken vitamin b6 supplements in an attempt to cure carpal tunnel syndrome and sleep disorders even though such treatment seems to be in- effective or at least inconclusive.7 self-prescribing is ill-advised because large doses of vitamin b6 taken for months or years may cause irreversible nerve degeneration. -vitamin b6 food sources as you can see from the colors in figure 10-8 (p. 337), meats, fish, and poultry (red bars), potatoes and a few other vegetables (green bars), and fruits (purple bars) offer vitamin b6. -as is true of most of the other vitamins, fruits and vegetables would rank considerably higher if foods were judged by nutri- ent density (vitamin b6 per kcalorie). -several servings of vitamin b6 rich foods are needed to meet recommended intakes. -foods lose vitamin b6 when heated. -information is limited, but vitamin b6 bioavailability from plant-derived foods seems to be lower than from animal- * inh stands for isonicotinic acid hydrazide. -the water soluble vitamins: b vitamins and vitamin c 337 figure 10-8 vitamin b6 in selected foods see the how to section on p. 329 for more information on using this figure. -food serving size (kcalories) 0 0.5 milligrams 1.0 1.5 2.0 bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice banana orange strawberries c (31 kcal) c fresh (22 kcal) c cooked (99 kcal) 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: 3 4 prune juice 3 oz baked (135 kcal) bluefish 1 2 c baked (69 kcal) squash, acorn c (137 kcal) c (76 kcal) rda for adults (19 50 yr) vitamin b6 many foods including vegetables, fruits, and meats offer vitamin b6. -variety helps a person meet vitamin b6 needs. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie derived foods. -fiber does not appear to interfere with absorption of vitamin b6. -the summary table lists food sources of vitamin b6 as well as its chief functions in the body and the common symptoms of deficiency and toxicity. -in summary vitamin b6 other names significant sources pyridoxine, pyridoxal, pyridoxamine rda adults (19 50 yr): 1.3 mg/day upper level adults: 100 mg/day chief functions in the body part of coenzymes plp (pyridoxal phosphate) and pmp (pyridoxamine phosphate) used in amino acid and fatty acid metabolism; helps to convert tryptophan to niacin and to serotonin; helps to make red blood cells asmall-cell type anemia is called microcytic anemia. -meats, fish, poultry, potatoes and other starchy vegetables, legumes, noncitrus fruits, fortified cereals, liver, soy products easily destroyed by heat deficiency symptoms scaly dermatitis; anemia (small-cell type);a depression, confusion, convulsions toxicity symptoms depression, fatigue, irritability, headaches, nerve damage causing numbness and muscle weakness leading to an inability to walk and convulsions; skin lesions . -c n i s o i d u t s l a r a o p most protein-rich foods such as meat, fish, and poultry provide ample vitamin b6; some veg- etables and fruits are good sources, too. -338 chapter 10 to calculate dfe: dfe = g food folate + (1.7 (cid:4) g synthetic folate) using the example in the text: 100 g food + 170 g supplement (1.7 (cid:4) 100 g) 270 g dfe the two main types of neural tube defects are spina bifida (literally, split spine ) and anencephaly ( no brain ). -women of childbearing age (15 to 45 yr) should: eat folate-rich foods eat folate-fortified foods take a multivitamin daily (most provide 400 g folate) reminder: a milligram (mg) is one-thou- sandth of a gram. -a microgram ( g) is one-thousandth of a milligram (or one- millionth of a gram). -0.4 mg = 400 g folate (fole-ate): a b vitamin; also known as folic acid, folacin, or pteroylglutamic (tare-o- eel-glue-tam-ick) acid (pga). -the coenzyme forms are dhf (dihydrofolate) and thf (tetrahydrofolate). -dietary folate equivalents (dfe): the amount of folate available to the body from naturally occurring sources, fortified foods, and supplements, accounting for differences in the bioavailability from each source. -neural tube defects: malformations of the brain, spinal cord, or both during embryonic development that often result in lifelong disability or death. -neural tube: the embryonic tissue that forms the brain and spinal cord. -folate folate, also known as folacin or folic acid, has a chemical name that would fit a flying dinosaur: pteroylglutamic acid (pga for short). -its primary coenzyme form, thf (tetrahydrofolate), serves as part of an enzyme complex that transfers one- carbon compounds that arise during metabolism. -this action helps convert vita- min b12 to one of its coenzyme forms and helps synthesize the dna required for all rapidly growing cells. -foods deliver folate mostly in the bound form that is, combined with a string of amino acids (glutamate), known as polyglutamate. -(see appendix c for the chemical structure.) -the small intestine prefers to absorb the free folate form folate with only one glutamate attached (the monoglutamate form).8 en- zymes on the intestinal cell surfaces hydrolyze the polyglutamate to monogluta- mate and several glutamates. -then the monoglutamate is attached to a methyl group (ch3). -special transport systems deliver the monoglutamate with its methyl group to the liver and other body cells. -for the folate coenzyme to function, the methyl group must be removed by an enzyme that requires the help of vitamin b12. -without that help, folate be- comes trapped inside cells in its methyl form, unavailable to support dna syn- thesis and cell growth. -figure 10-9 summarizes the process of folate s absorption and activation. -to dispose of excess folate, the liver secretes most of it into bile and ships it to the gallbladder. -thus folate returns to the intestine in an enterohepatic circulation route like that of bile itself (review figure 5-16, p. 151). -this complicated system for handling folate is vulnerable to gi tract injuries. -because folate is actively secreted back into the gi tract with bile, it has to be reabsorbed repeatedly. -if the gi tract cells are damaged, then folate is rapidly lost from the body. -such is the case in alcohol abuse; folate deficiency rapidly develops and, ironically, further damages the gi tract. -the folate coenzymes, remember, are active in cell multiplication and the cells lining the gi tract are among the most rapidly renewed cells in the body. -when unable to make new cells, the gi tract deteriorates and not only loses folate, but also fails to absorb other nutrients. -folate recommendations the bioavailability of folate ranges from 50 percent for foods to 100 percent for supplements taken on an empty stomach. -these differ- ences in bioavailability were considered when establishing the folate rda. -natu- rally occurring folate from foods is given full credit. -synthetic folate from fortified foods and supplements is given extra credit because, on average, it is 1.7 times more available than naturally occurring food folate. -thus a person consuming 100 micro- grams of folate from foods and 100 micrograms from a supplement receives 270 di- etary folate equivalents (dfe). -(the how to on p. 339 describes how to estimate dietary folate equivalents.) -the need for folate rises considerably during pregnancy and whenever cells are multiplying, so the recommendations for preg- nant women are considerably higher than for other adults. -folate and neural tube defects folate has proven to be critical in reducing the risks of neural tube defects.9 the brain and spinal cord develop from the neural tube, and defects in its orderly formation during the early weeks of preg- nancy may result in various central nervous system disorders and death. -(chap- ter 15 includes photos of neural tube development and an illustration of a neural tube defect.) -folate supplements taken one month before conception and continued throughout the first trimester of pregnancy can help prevent neural tube defects. -for this reason, all women of childbearing age who are capable of becoming pregnant should consume 0.4 milligram (400 micrograms) of folate daily, al- though only one-third of them actually do.10 this recommendation can be met through a diet that includes at least five servings of fruits and vegetables daily, but many women typically fail to do so and receive only half this amount from foods. -figure 10-9 folate s absorption and activation cooh ch2 ch2 o c nh ch cooh ring structure + glutamate folate the water soluble vitamins: b vitamins and vitamin c 339 in foods, folate naturally occurs as polyglutamate. -(folate occurs as mono- glutamate in fortified foods and supplements.) -spinach + ch3 in the intestine, digestion breaks glutamates off . -. -. -and adds a methyl group. -folate is absorbed and delivered to cells. -intestine ch3 in the cells, folate is trapped in its inactive form. -cell b12 ch3 to activate folate, vitamin b12 removes and keeps the methyl group, which activates vitamin b12. -b12 ch3 both the folate coenzyme and the vitamin b12 coenzyme are now active and available for dna synthesis. -dna how to estimate dietary folate equivalents folate is expressed in terms of dfe (dietary folate equivalents) because synthetic folate from supplements and fortified foods is absorbed at almost twice (1.7 times) the rate of naturally occurring folate from other foods. -use the following equation to calculate: dfe (cid:3) g food folate (cid:6) (1.7 (cid:4) g synthetic folate) consider, for example, a pregnant woman who takes a supplement and eats a bowl of fortified cornflakes, 2 slices of fortified bread, and a cup of fortified pasta. -from the supplement and fortified foods, she obtains synthetic folate: supplement fortified cornflakes fortified bread fortified pasta 100 g folate 100 g folate 40 g folate 60 g folate 300 g folate to calculate the dfe, multiply the amount of synthetic folate by 1.7: 300 g (cid:4) 1.7 (cid:3) 510 g dfe now add the naturally occurring folate from the other foods in her diet in this example, another 90 g of folate. -510 g dfe (cid:6) 90 g (cid:3) 600 g dfe notice that if we had not converted synthetic folate from supplements and fortified foods to dfe, then this woman s intake would appear to fall short of the 600 g recommendation for pregnancy (300 g (cid:6) 90 g (cid:3) 390 g). -but as our example shows, her intake does meet the recommendation. -at this time, supple- ment and fortified food labels list folate in g only, not g dfe, making such calcula- tions necessary. -to practice estimating folate equivalents, log on to www.thomsonedu.com/thomsonnow, go to chap- ter 10, then go to how to. -340 chapter 10 figure 10-10 decreasing spina bifida rates since folate fortification neural tube defects have declined since folate fortification began in 1996. -30 25 20 key: rate per 100,000 15 1991 1996 2001 source: national vital statistics system, national center for health statistics, centers for disease control. -furthermore, because of the enhanced bioavailability of synthetic folate, supple- mentation or fortification improves folate status significantly. -women who have given birth to infants with neural tube defects previously should consume 4 mil- ligrams of folate daily before conception and throughout the first trimester of pregnancy. -because half of the pregnancies each year are unplanned and because neural tube defects occur early in development before most women realize they are preg- nant, the food and drug administration (fda) has mandated that grain products be fortified to deliver folate to the u.s. -population. -* labels on fortified products may claim that adequate intake of folate has been shown to reduce the risk of neural tube defects. -fortification has improved folate status in women of child- bearing age and lowered the number of neural tube defects that occur each year, as figure 10-10 shows.11 whether additional fortification will help save even more in- fants is a topic of current debate.12 folate fortification raises safety concerns as well, especially because folate in- takes from fortified foods are more than twice as high as originally predicted.13 be- cause high intakes of folate complicate the diagnosis of a vitamin b12 deficiency, folate consumption should not exceed 1 milligram daily without close medical supervision.14 some research suggests a relationship between abnormal folate metabolism and non-neural tube birth defects such as down syndrome.15 folate s exact role, however, remains unclear, and supplementation does not appear to decrease the prevalence of down syndrome.16 some women whose infants develop these defects are not deficient in folate, and others with severe folate deficiencies do not give birth to infants with birth defects.17 researchers continue to look for other factors that must also be involved. -folate and heart disease the fda s decision to fortify grain products with fo- late was strengthened by research indicating an important role for folate in defend- ing against heart disease. -as chapter 6 mentioned, research indicates that high levels of the amino acid homocysteine and low levels of folate increase the risk of fa- tal heart disease.18 one of folate s key roles in the body is to break down homocys- * bread products, flour, corn grits, cornmeal, farina, rice, macaroni, and noodles must be fortified with 140 micrograms of folate per 100 grams of grain. -for perspective, 100 grams is roughly 3 slices of bread; 1 cup of flour; 1/2 cup of corn grits, cornmeal, farina, or rice; or 3/4 cup of macaroni or noodles. -the water soluble vitamins: b vitamins and vitamin c 341 teine. -without folate, homocysteine accumulates, which seems to enhance blood clot formation and arterial wall deterioration. -fortified foods and folate supple- ments raise blood folate and reduce blood homocysteine levels to an extent that may help to prevent heart disease.19 supplements do not seem to reduce the risk of death from cardiovascular causes.20 folate and cancer folate may also play a role in preventing cancer.21 notably, folate may be most effective in protecting those most likely to develop cancers: men who smoke (against pancreatic cancer) and women who drink alcohol (against breast cancer).22 folate deficiency folate deficiency impairs cell division and protein synthesis processes critical to growing tissues. -in a folate deficiency, the replacement of red blood cells and gi tract cells falters. -not surprisingly, then, two of the first symp- toms of a folate deficiency are anemia and gi tract deterioration. -the anemia of folate deficiency is characterized by large, immature red blood cells. -without folate, dna damage destroys many of the red blood cells as they attempt to divide and mature.23 the result is fewer, but larger, red blood cells that cannot carry oxygen or travel through the capillaries as efficiently as normal red blood cells. -folate deficiencies may develop from inadequate intake and have been re- ported in infants who were fed goat s milk, which is notoriously low in folate. -fo- late deficiency may also result from impaired absorption or an unusual metabolic need for the vitamin. -metabolic needs increase in situations where cell multiplica- tion must speed up, such as pregnancies involving twins and triplets; cancer; skin- destroying diseases such as chicken pox and measles; and burns, blood loss, gi tract damage, and the like. -of all the vitamins, folate appears to be most vulnerable to interactions with drugs, which can lead to a secondary deficiency. -some medications, notably anti- cancer drugs, have a chemical structure similar to folate s structure and can dis- place the vitamin from enzymes and interfere with normal metabolism. -like all cells, cancer cells need the real vitamin to multiply without it, they die. -unfortu- nately, these drugs affect both cancerous cells and healthy cells, and they create a folate deficiency for all cells. -(highlight 17 discusses nutrient-drug interactions and includes a figure illustrating the similarities between the vitamin folate and the anticancer drug methotrexate.) -aspirin and antacids also interfere with the body s handling of folate. -healthy adults who use these drugs to relieve an occasional headache or upset stomach need not be concerned, but people who rely heavily on aspirin or antacids should be aware of the nutrition consequences. -oral contraceptives may also impair fo- late status, as may smoking.24 folate toxicity naturally occurring folate from foods alone appears to cause no harm. -excess folate from fortified foods or supplements, however, can reach levels that are high enough to obscure a vitamin b12 deficiency and delay diag- nosis of neurological damage. -for this reason, an upper level has been estab- lished for folate from fortified foods or supplements (see the inside front cover). -folate food sources figure 10-11 (p. 342) shows that folate is especially abundant in legumes, fruits, and vegetables. -the vitamin s name suggests the word foliage, and indeed, leafy green vegetables are outstanding sources. -with fortification, grain products also contribute folate. -the small red and white bars in figure 10-11 indicate that meats, milk, and milk products are poor fo- late sources. -heat and oxidation during cooking and storage can destroy as much as half of the folate in foods. -the table on the next page provides a sum- mary of folate information. -. -c n i s o i d u t s a r a l o p leafy dark green vegetables (such as spinach and broccoli), legumes (such as black beans, kidney beans, and black-eyed peas), liver, and some fruits (notably citrus fruits and juices) are naturally rich in folate. -large-cell anemia is known as macro- cytic or megaloblastic anemia. -macro = large cyte = cell mega = large anemia (ah-nee-me-ah): literally, too little blood. -anemia is any condition in which too few red blood cells are present, or the red blood cells are immature (and therefore large) or too small or contain too little hemoglobin to carry the normal amount of oxygen to the tissues. -it is not a disease itself but can be a symptom of many different disease conditions, including many nutrient deficiencies, bleeding, excessive red blood cell destruction, and defective red blood cell formation. -an = without emia = blood 342 chapter 10 figure 10-11 folate in selected foods see the how to section on p. 329 for more information on using this figure. -micrograms food serving size (kcalories) 0 50 100 150 200 250 300 350 400 bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice banana orange strawberries watermelon 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 1 2 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) c fresh (22 kcal) c (31 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: 1 2 lentils 1 2 asparagus 3 4 orange juice c cooked (115 kcal) c cooked (22 kcal) c fresh (84 kcal) c (76 kcal) rda for adults folate vegetables (green) and legumes (brown) are rich sources of folate, as are fortified grain products (yellow). -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie in summary folate other names significant sources folic acid, folacin, pteroylglutamic acid (pga) rda adults: 400 g/day upper level adults: 1000 g/day chief functions in the body fortified grains, leafy green vegetables, legumes, seeds, liver easily destroyed by heat and oxygen deficiency symptoms anemia (large-cell type);a smooth, red tongue;b mental confusion, weakness, fatigue, irritability, headache; shortness of breath; elevated homocysteine part of coenzymes thf (tetrahydrofolate) and dhf (dihydrofolate) used in dna synthesis and therefore important in new cell formation toxicity symptoms masks vitamin b12 deficiency symptoms alarge-cell type anemia is known as either macrocytic or megaloblastic anemia. -bsmoothness of the tongue is caused by loss of its surface structures and is termed glossitis (gloss-eye-tis). -vitamin b12: a b vitamin characterized by the presence of cobalt (see figure 13-12, p. 462). -the active forms of coenzyme b12 are methylcobalamin and deoxyadenosylcobalamin. -vitamin b12 vitamin b12 and folate are closely related: each depends on the other for activa- tion. -recall that vitamin b12 removes a methyl group to activate the folate coen- the water soluble vitamins: b vitamins and vitamin c 343 zyme. -when folate gives up its methyl group, the vitamin b12 coenzyme becomes ac- tivated (review figure 10-9 on p. 339). -the regeneration of the amino acid methionine and the synthesis of dna and rna depend on both folate and vitamin b12. -* in addition, without any help from folate, vitamin b12 maintains the sheath that surrounds and protects nerve fibers and promotes their normal growth. -bone cell activity and metabolism also depend on vitamin b12. -in the stomach, hydrochloric acid and the digestive enzyme pepsin release vita- min b12 from the proteins to which it is attached in foods. -the stomach also secretes a molecule called intrinsic factor. -as vitamin b12 passes to the small intestine, it binds with intrinsic factor. -bound together, intrinsic factor and vitamin b12 travel to the end of the small intestine, where receptors recognize the complex. -(importantly, the receptors do not recognize vitamin b12 alone without intrinsic factor.) -there the intrinsic factor is degraded, and the vitamin is gradually absorbed into the blood- stream. -transport of vitamin b12 in the blood depends on specific binding proteins. -like folate, vitamin b12 follows the enterohepatic circulation route. -it is continu- ally secreted into bile and delivered to the intestine, where it is reabsorbed. -because most vitamin b12 is reabsorbed, healthy people rarely develop a deficiency even when their intake is minimal. -vitamin b12 recommendations the rda for adults is only 2.4 micrograms of vitamin b12 a day just over two-millionths of a gram. -the ink in the period at the end of this sentence may weigh about 2.4 micrograms. -but tiny though this amount appears to the human eye, it contains billions of molecules of vitamin b12, enough to provide coenzymes for all the enzymes that need its help. -vitamin b12 deficiency and toxicity most vitamin b12 deficiencies reflect inad- equate absorption, not poor intake. -inadequate absorption typically occurs for one of two reasons: a lack of hydrochloric acid or a lack of intrinsic factor. -without hy- drochloric acid, the vitamin is not released from the dietary proteins and so is not available for binding with the intrinsic factor. -without the intrinsic factor, the vita- min cannot be absorbed. -many people, especially those over 50, develop atrophic gastritis, a common condition in older people that damages the cells of the stomach. -atrophic gastritis may also develop in response to iron deficiency or infection with helicobacter pylori, the bacterium implicated in ulcer formation. -without healthy stomach cells, pro- duction of hydrochloric acid and intrinsic factor diminishes. -even with an ade- quate intake from foods, vitamin b12 status suffers. -the vitamin b12 deficiency caused by atrophic gastritis and a lack of intrinsic factor is known as pernicious anemia. -some people inherit a defective gene for the intrinsic factor. -in such cases, or when the stomach has been injured and cannot produce enough of the intrinsic factor, vitamin b12 must be injected to bypass the need for intestinal absorption. -al- ternatively, the vitamin may be delivered by nasal spray; absorption is rapid, high, and well tolerated. -a prolonged inadequate intake, as can occur with a vegan diet, may also cre- ate a vitamin b12 deficiency.25 people who stop eating animal-derived foods con- taining vitamin b12 may take several years to develop deficiency symptoms because the body recycles much of its vitamin b12, reabsorbing it over and over again. -even when the body fails to absorb vitamin b12, deficiency may take up to three years to develop because the body conserves its supply. -because vitamin b12 is required to convert folate to its active form, one of the most obvious vitamin b12 deficiency symptoms is the anemia of folate deficiency. -this anemia is characterized by large, immature red blood cells, which indicate slow dna synthesis and an inability to divide (see figure 10-12, p. 344). -when folate is * in the body, methionine serves as a methyl (ch3) donor. -in doing so, methionine can be converted to other amino acids. -some of these amino acids can regenerate methionine, but methionine is still con- sidered an essential amino acid that is needed in the diet. -vitamin b12 is found primarily in foods derived from animals. -intrinsic factor: a glycoprotein (a protein with short polysaccharide chains attached) secreted by the stomach cells that binds with vitamin b12 in the small intestine to aid in the absorption of vitamin b12. -intrinsic = on the inside atrophic (a-tro-fik) gastritis (gas-try-tis): chronic inflammation of the stomach accompanied by a diminished size and functioning of the mucous membrane and glands. -atrophy = wasting gastro = stomach itis = inflammation pernicious (per-nish-us) anemia: a blood disorder that reflects a vitamin b12 deficiency caused by lack of intrinsic factor and characterized by abnormally large and immature red blood cells. -other symptoms include muscle weakness and irreversible neurological damage. -pernicious = destructive 344 chapter 10 figure 10-12 normal and anemic blood cells the anemia of folate deficiency is indistinguishable from that of vitamin b12 defi- ciency. -appendix e describes the biochemical tests used to differentiate the two conditions. ) -h t o b ( d e t i m i l n u s l a u s i v / l a c i g o l o i b normal blood cells. -the size, shape, and color of these red blood cells show that they are normal. -blood cells in pernicious anemia (mega- loblastic). -these megaloblastic blood cells are slightly larger than normal red blood cells, and their shapes are irregular. -a n i d r a c trapped in its inactive (methyl folate) form due to vitamin b12 deficiency or is un- available due to folate deficiency itself, dna synthesis slows. -first to be affected in a vitamin b12 or folate deficiency are the rapidly growing blood cells. -either vitamin b12 or folate will clear up the anemia, but if folate is given when vitamin b12 is needed, the result is disastrous: devastating neurological symptoms. -remember that vitamin b12, but not folate, maintains the sheath that surrounds and protects nerve fibers and promotes their normal growth. -folate cures the blood symptoms of a vitamin b12 deficiency, but cannot stop the nerve symptoms from progressing. -by doing so, folate masks a vitamin b12 deficiency. -marginal vitamin b12 deficiency impairs performance on tests measuring intelli- gence, spatial ability, and short-term memory. -advanced neurological symptoms include a creeping paralysis that begins at the extremities and works inward and up the spine. -early detection and correction are necessary to prevent permanent nerve damage and paralysis. -with sufficient folate in the diet, the neurological symptoms of vitamin b12 deficiency can develop without evidence of anemia. -such interactions between folate and vitamin b12 highlight some of the safety issues sur- rounding the use of supplements and the fortification of foods. -no adverse effects have been reported for excess vitamin b12, and no upper level has been set. -vitamin b12 food sources vitamin b12 is unique among the vitamins in being found almost exclusively in foods derived from animals. -anyone who eats reason- able amounts of meat is guaranteed an adequate intake, and vegetarians who use milk products or eggs are also protected from deficiency. -vegans, who restrict all foods derived from animals, need a reliable source, such as vitamin b12 fortified soy milk or vitamin b12 supplements. -yeast grown on a vitamin b12 enriched medium and mixed with that medium provides some vitamin b12, but yeast itself does not contain active vitamin b12. -fermented soy products such as miso (a soybean paste) and sea algae such as spirulina also do not provide active vitamin b12. -extensive re- search shows that the amounts listed on the labels of these plant products are inac- curate and misleading because the vitamin b12 is in an inactive, unavailable form. -as mentioned earlier, the water-soluble vitamins are particularly vulnerable to losses in cooking. -for most of these nutrients, microwave heating minimizes losses as well as, or better than, traditional cooking methods. -such is not the case for vi- tamin b12, however. -microwave heating inactivates vitamin b12. -to preserve this vi- tamin, use the oven or stovetop instead of a microwave to cook meats and milk the water soluble vitamins: b vitamins and vitamin c 345 products (major sources of vitamin b12). -the accompanying table provides a sum- mary of information about vitamin b12. -in summary vitamin b12 other names significant sources cobalamin (and related forms) rda adults: 2.4 g/day chief functions in the body part of coenzymes methylcobalamin and deoxyadenosylcobalamin used in new cell synthesis; helps to maintain nerve cells; re- forms folate coenzyme; helps to break down some fatty acids and amino acids foods of animal origin (meat, fish, poultry, shellfish, milk, cheese, eggs), fortified cereals easily destroyed by microwave cooking deficiency disease pernicious anemiaa deficiency symptoms anemia (large-cell type);b fatigue, degeneration of peripheral nerves progressing to paralysis; sore tongue, loss of appetite, constipation toxicity symptoms none reported athe name pernicious anemia refers to the vitamin b12 deficiency caused by atrophic gastritis and a lack of intrinsic factor, but not to that caused by inadequate dietary intake. -blarge-cell type anemia is known as either macrocytic or megaloblastic anemia. -non-b vitamins nutrition scientists debate whether other dietary compounds might also be consid- ered vitamins. -in some cases, the compounds may be conditionally essential that is, needed by the body from foods when synthesis becomes insufficient to support normal growth and metabolism. -in other cases, the compounds may be vitamin im- postors not needed under any circumstances. -choline determining whether choline is an essential nutrient has been blurry for decades, in part because the body can make choline from the amino acid methion- ine. -furthermore, choline is commonly found in many foods as part of the lecithin molecule (review figure 5-9 on p. 146). -consequently, choline deficiencies are rare. -without any dietary choline, however, synthesis alone appears to be insufficient to meet the body s needs, making choline a conditionally essential nutrient. -for this rea- son, the 1998 dri report established an adequate intake (ai) for choline. -the body uses choline to make the neurotransmitter acetylcholine and the phospholipid lecithin. -during fetal development, choline supports the structure and function of the brain and spinal chord.26 the accompanying table summarizes key choline facts. -in summary choline adequate intake (ai) deficiency symptoms men: 550 mg/day women: 425 mg/day upper level adults: 3500 mg/day liver damage toxicity symptoms body odor, sweating, salivation, reduced growth rate, low blood pressure, liver damage chief functions in the body needed for the synthesis of the neurotransmitter acetylcholine and the phospholipid lecithin significant sources milk, liver, eggs, peanuts reminder: choline is a nitrogen-containing compound found in foods and made in the body from the amino acid methionine. -choline is part of the phospholipid lecithin and the neurotransmitter acetylcholine. -346 chapter 10 inositol (in-oss-ih-tall): a nonessential nutrient that can be made in the body from glucose. -inositol is a part of cell membrane structures. -carnitine (car-neh-teen): a nonessential, nonprotein amino acid made in the body from lysine that helps transport fatty acids across the mitochondrial membrane. -inositol and carnitine inositol is a part of cell membrane structures, and car- nitine transports long-chain fatty acids from the cytosol to the mitochondria for ox- idation. -like choline, these two substances can be made by the body, but unlike choline, no recommendations have been established. -researchers continue to ex- plore the possibility that these substances may be essential. -even if they are essen- tial, though, supplements are unnecessary because these compounds are widespread in foods. -some vitamin companies include choline, inositol, and carnitine in their formu- lations to make their vitamin pills look more complete than others, but this strat- egy offers no real advantage. -for a rational way to compare vitamin-mineral supplements, read highlight 10. vitamin impostors other substances have been mistaken for essential nutrients for human beings because they are needed for growth by bacteria or other forms of life. -among them are paba (para-aminobenzoic acid, a component of folate s ring structure), the bioflavonoids (vitamin p or hesperidin), pyrroloquinoline quinone (methoxatin), orotic acid, lipoic acid, and ubiquinone (coenzyme q10). -other names erroneously associated with vitamins are vitamin o (oxygenated salt water), vi- tamin b5 (another name for pantothenic acid), vitamin b15 (also called pangamic acid, a hoax), and vitamin b17 (laetrile, an alleged cancer cure and not a vitamin or a cure by any stretch of the imagination in fact, laetrile is a po- tentially dangerous substance). -in summary the b vitamins serve as coenzymes that facilitate the work of every cell. -they are active in carbohydrate, fat, and protein metabolism and in the making of dna and thus new cells. -historically famous b vitamin deficiency diseases are beriberi (thiamin), pellagra (niacin), and pernicious anemia (vitamin b12). -pellagra can be prevented by adequate protein because the amino acid tryp- tophan can be converted to niacin in the body. -a high intake of folate can mask the blood symptoms of a vitamin b12 deficiency, but it will not prevent the associated nerve damage. -vitamin b6 participates in amino acid metabo- lism and can be harmful in excess. -biotin and pantothenic acid serve impor- tant roles in energy metabolism and are common in a variety of foods. -many substances that people claim as b vitamins are not. -the b vitamins in concert this chapter has described some of the impressive ways that vitamins work individ- ually, as if their many actions in the body could easily be disentangled. -in fact, it is often difficult to tell which vitamin is truly responsible for a given effect because the nutrients are interdependent; the presence or absence of one affects another s ab- sorption, metabolism, and excretion. -you have already seen this interdependence with folate and vitamin b12. -riboflavin and vitamin b6 provide another example. -one of the riboflavin coen- zymes, fmn, assists the enzyme that converts vitamin b6 to its coenzyme form plp. -consequently, a severe riboflavin deficiency can impair vitamin b6 activity.27 thus a deficiency of one nutrient may alter the action of another. -furthermore, a defi- ciency of one nutrient may create a deficiency of another. -for example, both ri- boflavin and vitamin b6 (as well as iron) are required for the conversion of tryptophan to niacin. -consequently, an inadequate intake of either riboflavin or vi- tamin b6 can diminish the body s niacin supply. -these interdependent relationships are evident in many of the roles b vitamins play in the body. -the water soluble vitamins: b vitamins and vitamin c 347 b vitamin roles figure 10-13 summarizes the metabolic pathways introduced in chapter 7 and conveys an impression of the many ways b vitamins assist in those metabolic path- ways. -metabolism is the body s work, and the b vitamin coenzymes are indispensa- ble to every step. -in scanning the pathways of metabolism depicted in the figure, note the many abbreviations for the coenzymes that keep the processes going. -look at the now-familiar pathway of glucose breakdown. -to break down glu- cose to pyruvate, the cells must have certain enzymes. -for the enzymes to work, they must have the niacin coenzyme nad. -to make nad, the cells must be sup- plied with niacin (or enough of the amino acid tryptophan to make niacin). -they can make the rest of the coenzyme without dietary help. -figure 10-13 animated! -metabolic pathways involving b vitamins these metabolic pathways were introduced in chapter 7 and are presented here to highlight the many coenzymes that facilitate the reactions. -these coenzymes depend on the following vitamins: nad and nadp: niacin tpp: thiamin coa: pantothenic acid b12: vitamin b12 pathways leading toward acetyl coa and the tca cycle are catabolic, and those leading toward amino acids, glycogen, and fat are anabolic. -for further details, see appendix c. fmn and fad: riboflavin thf: folate plp: vitamin b6 biotin some amino acids nad plp plp b12 some amino acids some amino acids thf plp nad biotin some amino acids plp plp glycogen plp glucose nad pyruvate nad tpp fad acetyl coa nad nad tpp fad nad tca cycle tca cycle fad coa nadp biotin nad fad fat thf b12 other compounds fmn yields energy electron transport chain nad fad yields energy yields energy to test your understanding of these concepts, log on to www.thomsonedu.com/login 348 chapter 10 for want of a nail, a horseshoe was lost. -for want of a horseshoe, a horse was lost. -for want of a horse, a soldier was lost. -for want of a soldier, a battle was lost. -for want of a battle, the war was lost, and all for the want of a horseshoe nail! -mother goose the next step is the breakdown of pyruvate to acetyl coa. -the enzymes involved in this step require both nad and the thiamin and riboflavin coenzymes tpp and fad, respectively. -the cells can manufacture the enzymes they need from the vita- mins, if the vitamins are in the diet. -another coenzyme needed for this step is coa. -predictably, the cells can make coa except for an essential part that must be obtained in the diet pantothenic acid. -another coenzyme requiring biotin serves the enzyme complex involved in converting pyruvate to oxaloacetate, the compound that combines with acetyl coa to start the tca cycle. -these and other coenzymes participate throughout all the metabolic pathways. -when the diet provides riboflavin, the body synthesizes fad a needed coenzyme in the tca cycle. -vitamin b6 is an indispensable part of plp a coenzyme required for many amino acid conversions, for a crucial step in the making of the iron- containing portion of hemoglobin for red blood cells, and for many other reactions. -folate becomes thf the coenzyme required for the synthesis of new genetic mate- rial and therefore new cells. -the vitamin b12 coenzyme, in turn, regenerates thf to its active form; thus vitamin b12 is also necessary for the formation of new cells. -thus each of the b vitamin coenzymes is involved, directly or indirectly, in en- ergy metabolism. -some facilitate the energy-releasing reactions themselves; others help build new cells to deliver the oxygen and nutrients that allow the energy reac- tions to occur. -b vitamin deficiencies now suppose the body s cells lack one of these b vitamins niacin, for example. -without niacin, the cells cannot make nad. -without nad, the enzymes involved in every step of the glucose-to-energy pathway cannot function. -then, because all the body s activities require energy, literally everything begins to grind to a halt. -this is no exaggeration. -the deadly disease pellagra, caused by niacin deficiency, produces the devastating four ds : dermatitis, which reflects a failure of the skin; dementia, a failure of the nervous system; diarrhea, a failure of digestion and absorption; and eventually, as would be the case for any severe nutrient deficiency, death. -these symptoms are the obvious ones, but a niacin deficiency affects all other organs, too, because all are dependent on the energy pathways. -in short, niacin is like the horse- shoe nail for want of which a war was lost. -all the vitamins are like horseshoe nails. -with any b vitamin deficiency, many body systems become deranged, and similar symptoms may appear. -a lack of horseshoe nails can have disastrous and far-reaching effects. -deficiencies of single b vitamins seldom show up in isolation, however. -after all, people do not eat nutrients singly; they eat foods, which contain mixtures of nutri- ents. -only in two cases described earlier beriberi and pellagra have dietary defi- ciencies associated with single b vitamins been observed on a large scale in human populations. -even in these cases, the deficiencies were not pure. -both diseases were attributed to deficiencies of single vitamins, but both were deficiencies of several vi- tamins in which one vitamin stood out above the rest. -when foods containing the vitamin known to be needed were provided, the other vitamins that were in short supply came as part of the package. -major deficiency diseases of epidemic proportions such as pellagra and beriberi are no longer seen in the united states and canada, but lesser deficiencies of nutri- ents, including the b vitamins, sometimes occur in people whose food choices are poor because of poverty, ignorance, illness, or poor health habits like alcohol abuse. -(review highlight 7 to fully appreciate how alcohol induces vitamin defi- ciencies and interferes with energy metabolism.) -remember from chapter 1 that deficiencies can arise not only from deficient intakes (primary causes), but also for other (secondary) reasons. -in identifying nutrient deficiencies, it is important to realize that a particular symptom may not always have the same cause. -the skin and the tongue (shown in figure 10-14) appear to be especially sensitive to b vitamin deficiencies, but iso- figure 10-14 b vitamin deficiency symptoms the smooth tongue of glossitis and the skin lesions of cheilosis the water soluble vitamins: b vitamins and vitamin c 349 o t o h p k c o t s l i a c d e m m o t s u c . -c n i , s r e h c r a e s e r o t o h p / y r a r b l i o t o h p e c n e c s i . -d e v r e s e r s t h g i r l l a i . -y t e c o s l i a c d e m s t t e s u h c a s s a m 4 0 0 2 a healthy tongue has a rough and somewhat bumpy surface. -in a b vitamin deficiency, the tongue becomes smooth and swollen due to atrophy of the tissue (glossitis). -in a b vitamin deficiency, the corners of the mouth become irritated and inflamed (cheilosis). -lating these body parts in the summary tables earlier in this chapter gives them un- due emphasis. -both the skin and the tongue are readily visible in a physical exam- ination. -the physician sees and reports the deficiency s outward symptoms, but the full impact of a vitamin deficiency occurs inside the cells of the body. -if the skin de- velops a rash or lesions, other tissues beneath it may be degenerating, too. -similarly, the mouth and tongue are the visible part of the digestive system; if they are abnor- mal, most likely the rest of the gi tract is, too. -the how to (p. 350) offers other in- sights into symptoms and their causes. -two symptoms commonly seen in b vita- min deficiencies are glossitis (gloss-eye- tis), an inflammation of the tongue, and cheilosis (kye-loh-sis or kee-loh-sis), a condition of reddened lips with cracks at the corners of the mouth. -glossa = tongue cheilos = lip b vitamin toxicities toxicities of the b vitamins from foods alone are unknown, but they can occur when people overuse supplements. -with supplements, the quantities can quickly over- whelm the cells. -consider that one small capsule can easily deliver 2 milligrams of vi- tamin b6, but it would take more than 3000 bananas, 6600 cups of rice, or 3600 chicken breasts to supply an equivalent amount. -when the cells become oversatu- rated with a vitamin, they must work to eliminate the excess. -the cells dispatch water- soluble vitamins to the urine for excretion, but sometimes they cannot keep pace with the onslaught. -homeostasis becomes disturbed and symptoms of toxicity develop. -b vitamin food sources significantly, deficiency diseases, such as beriberi and pellagra, were eliminated by supplying foods not pills. -vitamin pill advertisements make much of the fact that vitamins are indispensable to life, but human beings obtained their nourishment from foods for centuries before vitamin pills existed. -if the diet lacks a vitamin, the first solution is to adjust food intake to obtain that vitamin. -manufacturers of so-called natural vitamins boast that their pills are purified from real foods rather than synthesized in a laboratory. -think back on the course of human evolution; it is not natural to take any kind of pill. -in reality, the finest, most natural vitamin supplements available are whole grains, vegetables, fruits, meat, fish, poultry, eggs, legumes, nuts, and milk and milk products. -350 chapter 10 the tradition of providing british sailors with citrus juice daily to prevent scurvy gave them the nickname limeys. -scurvy: the vitamin c deficiency disease. -how to distinguish symptoms and causes the cause of a symptom is not always apparent. -the summary tables in this chapter show that deficiencies of riboflavin, niacin, biotin, and vitamin b6 can all cause skin rashes. -but so can a deficiency of protein, linoleic acid, or vitamin a. because skin is on the outside and easy to see, it is a useful indicator of things going wrong inside cells. -but, by itself, a skin symptom says nothing about its possible cause. -the same is true of anemia. -anemia is often caused by iron deficiency, but it can also be caused by a folate or vitamin b12 deficiency; by digestive tract failure to absorb any of these nutrients; or by such nonnutritional causes as infections, para- sites, cancer, or loss of blood. -no single nutrient will always cure a given symp- tom. -a person who feels chronically tired may be tempted to self-diagnose iron- deficiency anemia and self-prescribe an iron supplement. -but this will relieve tiredness only if the cause is indeed iron- deficiency anemia. -if the cause is a folate deficiency, taking iron will only prolong the fatigue. -a person who is better in- formed may decide to take a vitamin supplement with iron, covering the possi- bility of a vitamin deficiency. -but the symptom may have a nonnutritional cause. -if the cause of the tiredness is actually hidden blood loss due to cancer, the postponement of a diagnosis may be fatal. -when fatigue is caused by a lack of sleep, of course, no nutrient or combina- tion of nutrients can replace a good night s rest. -a person who is chronically tired should see a physician rather than self-prescribe. -if the condition is nutrition related, a registered dietitian should be consulted as well. -the bar graphs of selected foods in this chapter, taken together, sing the praises of a balanced diet. -the grains deliver thiamin, riboflavin, niacin, and folate. -the fruit and vegetable groups excel in folate. -the meat group serves thiamin, niacin, vitamin b6, and vitamin b12 well. -the milk group stands out for riboflavin and vi- tamin b12. -a diet that offers a variety of foods from each group, prepared with rea- sonable care, serves up ample b vitamins. -in summary the b vitamin coenzymes work together in energy metabolism. -some facilitate the energy-releasing reactions themselves; others help build cells to deliver the oxygen and nutrients that permit the energy pathways to run. -these vitamins depend on each other to function optimally; a deficiency of any of them cre- ates multiple problems. -fortunately, a variety of foods from each of the food groups provides an adequate supply of all of the b vitamins. -vitamin c two hundred and fifty years ago, any man who joined the crew of a seagoing ship knew he had at best a 50 50 chance of returning alive not because he might be slain by pi- rates or die in a storm, but because he might contract the dread disease scurvy. -as many as two-thirds of a ship s crew could die of scurvy during a long voyage. -only men on short voyages, especially around the mediterranean sea, were free of scurvy. -no one knew the reason: that on long ocean voyages, the ship s cook used up the fresh fruits and vegetables early and then served only cereals and meats until the return to port. -the first nutrition experiment ever performed on human beings was devised in the mid-1700s to find a cure for scurvy. -james lind, a british physician, divided 12 sailors with scurvy into 6 pairs. -each pair received a different supplemental ration: cider, vinegar, sulfuric acid, seawater, oranges and lemons, or a strong laxative mixed with spices. -those receiving the citrus fruits quickly recovered, but sadly, it was 50 years before the british navy required all vessels to provide every sailor with lime juice daily. -the water soluble vitamins: b vitamins and vitamin c 351 the antiscurvy something in limes and other foods was dubbed the antiscor- butic factor. -nearly 200 years later, the factor was isolated and found to be a six- carbon compound similar to glucose; it was named ascorbic acid. -shortly thereafter, it was synthesized, and today hundreds of millions of vitamin c pills are produced in pharmaceutical laboratories each year. -vitamin c roles vitamin c parts company with the b vitamins in its mode of action. -in some set- tings, vitamin c serves as a cofactor helping a specific enzyme perform its job, but in others, it acts as an antioxidant participating in more general ways. -as an antioxidant vitamin c loses electrons easily, a characteristic that allows it to perform as an antioxidant. -in the body, antioxidants defend against free radicals. -free radicals are discussed in highlight 11, but for now, a simple defini- tion will suffice. -a free radical is a molecule with one or more unpaired electrons, which makes it unstable and highly reactive. -by donating an electron or two, an- tioxidants neutralize free radicals and protect other substances from their dam- age. -figure 10-15 illustrates how vitamin c can give up electrons to stop free-radical damage and then accept them again to become reactivated. -this re- cycling of vitamin c is key to limiting losses and maintaining a reserve of antiox- idants in the body. -transporting and concentrating vitamin c in the cells enhances its role as an antioxidant.28 vitamin c is like a bodyguard for water-soluble substances; it stands ready to sacrifice its own life to save theirs. -in the cells and body fluids, vitamin c protects tissues from oxidative stress and thus may play an important role in preventing diseases. -in the intestines, vitamin c enhances iron absorption by protecting iron from oxidation. -(chapter 13 provides more details about the relationship between vitamin c and iron.) -as a cofactor in collagen formation vitamin c helps to form the fibrous structural protein of connective tissues known as collagen. -collagen serves as the matrix on which bones and teeth are formed. -when a person is wounded, collagen glues the separated tissues together, forming scars. -cells are held together largely by collagen; this is especially important in the artery walls, which must expand and contract with each beat of the heart, and in the thin capillary walls, which must withstand a pulse of blood every second or so without giving way. -chapter 6 described how the body makes proteins by stringing together chains of amino acids. -during the synthesis of collagen, each time a proline or lysine is added to the growing protein chain, an enzyme hydroxylates it (adds an oh group figure 10-15 active forms of vitamin c the two hydrogens highlighted in yellow give vitamin c its acidity and its ability to act as an antioxidant. -o c o ch ho ho c c ho ch ch2oh 2h+ 2h+ o c o ch o o c c ho ch ch2oh ascorbic acid protects against oxidative damage by donating its two hydrogens with their electrons to free radicals (molecules with unpaired electrons). -in doing so, ascorbic acid becomes dehydroascorbic acid. -dehydroascorbic acid can readily accept hydrogens to become ascorbic acid. -the reversibility of this reaction is key to vitamin c s role as an antioxidant. -reminder: a cofactor is a small, inorganic or organic substance that facilitates the action of an enzyme. -key antioxidant nutrients: vitamin c, vitamin e, beta-carotene selenium reminder: collagen is the structural protein from which connective tissues such as scars, tendons, ligaments, and the foundations of bones and teeth are made. -antiscorbutic (an-tee-skor-bue-tik) factor: the original name for vitamin c. anti = against scorbutic = causing scurvy ascorbic acid: one of the two active forms of vitamin c (see figure 10-15). -many people refer to vitamin c by this name. -a = without scorbic = having scurvy antioxidant: a substance in foods that significantly decreases the adverse effects of free radicals on normal physiological functions in the human body. -free radicals: unstable molecules with one or more unpaired electrons. -oxidative stress: a condition in which the production of oxidants and free radicals exceeds the body s ability to handle them and prevent damage. -352 chapter 10 figure 10-16 vitamin c intake (mg/day) recommendations for vitamin c are set generously above the minimum require- ment and well below the toxicity level. -3000 2000 adverse consequences may appear at such a high dose upper level for adults 200 125 110 100 90 75 30 10 0 limited absorption and little increase in blood concentrations at higher doses recommendation for men smokers recommendation for women smokers saturates tissues rda for men rda for women supports metabolism prevents scurvy to it), making the amino acid hydroxyproline or hydroxylysine, respectively. -these two special amino acids facilitate the binding together of collagen fibers to make strong, ropelike structures. -the conversion of proline to hydroxyproline requires both vitamin c and iron. -iron works as a cofactor in the reaction, and vitamin c protects iron from oxidation, thereby allowing iron to perform its duty. -without vi- tamin c and iron, the hydroxylation step does not occur. -as a cofactor in other reactions vitamin c also serves as a cofactor in the synthesis of several other compounds. -as in collagen formation, vitamin c helps in the hydroxylation of carnitine, a compound that transports long-chain fatty acids into the mitochondria of a cell for energy metabolism. -it participates in the conver- sions of the amino acids tryptophan and tyrosine to the neurotransmitters serotonin and norepinephrine, respectively. -vitamin c also assists in the making of hormones, including thyroxin, which regulates the metabolic rate; when metabolism speeds up in times of extreme physical stress, the body s use of vitamin c increases. -in stress the adrenal glands contain more vitamin c than any other organ in the body, and during stress, these glands release the vitamin, together with hormones, into the blood. -the vitamin s exact role in the stress reaction remains unclear, but physical stresses raise vitamin c needs. -among the stresses known to increase vitamin c needs are infections; burns; extremely high or low temperatures; intakes of toxic heavy met- als such as lead, mercury, and cadmium; the chronic use of certain medications, in- cluding aspirin, barbiturates, and oral contraceptives; and cigarette smoking. -when immune system cells are called into action, they use a great deal of oxygen and pro- duce free radicals. -in this case, free radicals are helpful. -they act as ammunition in an oxidative burst that demolishes the offending viruses and bacteria and destroys the damaged cells. -vitamin c steps in as an antioxidant to control this oxidative activity. -as a cure for the common cold newspaper headlines touting vitamin c as a cure for colds have appeared frequently over the years, but research supporting such claims has been conflicting and controversial. -some studies find no relationship be- tween vitamin c and the occurrence of the common cold, whereas others report fewer colds, fewer days, and shorter duration of severe symptoms.29 a review of the research on vitamin c in the treatment and prevention of the common cold reveals a modest benefit a significant difference in duration of less than a day per cold in favor of those taking a daily dose of at least 1 gram of vitamin c.30 the term significant means that statistical analysis suggests that the findings probably didn t arise by chance, but instead from the experimental treatment being tested. -is one day without a cold suf- ficient to warrant routine daily supplementation? -supplement users seem to think so. -interestingly, those who received the placebo but thought they were receiving vita- min c had fewer colds than the group who received vitamin c but thought they were receiving the placebo. -(never underestimate the healing power of faith!) -discoveries about how vitamin c works in the body provide possible links be- tween the vitamin and the common cold. -anyone who has ever had a cold knows the discomfort of a runny or stuffed-up nose. -nasal congestion develops in response to elevated blood histamine, and people commonly take antihistamines for relief. -like an antihistamine, vitamin c comes to the rescue and deactivates histamine. -in disease prevention whether vitamin c may help in preventing or treating cancer, heart disease, cataract, and other diseases is still being studied, and findings are presented in highlight 11. conducting research in the united states and canada can be difficult, however, because diets typically contribute enough vitamin c to provide optimal health benefits. -histamine (hiss-tah-mean or hiss-tah-men): a substance produced by cells of the immune system as part of a local immune reaction to an antigen; participates in causing inflammation. -vitamin c recommendations how much vitamin c does a person need? -as figure 10-16 illustrates, recommenda- tions are set generously above the minimum requirement to prevent scurvy and well below the toxicity level.31 the water soluble vitamins: b vitamins and vitamin c 353 for perspective, 1 c orange juice provides (cid:7)100 mg vitamin c. the requirement the amount needed to prevent the overt symptoms of scurvy is only 10 milligrams daily. -however, 10 milligrams a day does not satu- rate all the body tissues; higher intakes will increase the body s total vitamin c. at about 100 milligrams per day, 95 percent of the population probably reaches tis- sue saturation. -at about 200 milligrams, absorption reaches a maximum, and there is little, if any, increase in blood concentrations at higher doses. -excess vita- min c is readily excreted. -as mentioned earlier, cigarette smoking increases the need for vitamin c. ciga- rette smoke contains oxidants, which greedily deplete this potent antioxidant. -ex- posure to cigarette smoke, especially when accompanied by low intakes of vitamin c, depletes the body s pool in both active and passive smokers. -people who chew to- bacco also have low levels of vitamin c. because people who smoke cigarettes reg- ularly suffer significant oxidative stress, their requirement for vitamin c is increased an additional 35 milligrams; nonsmokers regularly exposed to cigarette smoke should also be sure to meet their rda for vitamin c. vitamin c deficiency two of the most notable signs of a vitamin c deficiency reflect its role in maintain- ing the integrity of blood vessels. -the gums bleed easily around the teeth, and cap- illaries under the skin break spontaneously, producing pinpoint hemorrhages (see figure 10-17). -when the vitamin c pool falls to about a fifth of its optimal size (this may take more than a month on a diet lacking vitamin c), scurvy symptoms begin to appear. -inadequate collagen synthesis causes further hemorrhaging. -muscles, including the heart muscle, degenerate. -the skin becomes rough, brown, scaly, and dry. -wounds fail to heal because scar tissue will not form. -bone rebuilding falters; the ends of the long bones become softened, malformed, and painful, and fractures develop. -the teeth become loose as the cartilage around them weakens. -anemia and infections are common. -there are also characteristic psychological signs, including hysteria and depression. -sudden death is likely, caused by massive internal bleeding. -once diagnosed, scurvy is readily resolved by vitamin c. moderate doses in the neighborhood of 100 milligrams per day are sufficient, curing the scurvy within about five days. -such an intake is easily achieved by including vitamin c rich foods in the diet. -vitamin c toxicity the availability of vitamin c supplements and the publication of books recom- mending vitamin c to prevent colds and cancer have led thousands of people to figure 10-17 vitamin c deficiency symptoms scorbutic gums and pinpoint hemorrhages . -c n i , s e t a i c o s s a & n a m g r e b . -v . -l . -c n i s r e h r a e s e r o t o h p / i z z a r a m p. . -r d scorbutic gums. -unlike other lesions of the mouth, scurvy presents a symmetrical appearance without infection. -pinpoint hemorrhages. -small red spots appear in the skin, indicating spontaneous bleeding internally. -354 chapter 10 when dietitians say vitamin c, people think citrus fruits . -. -. -. -. -. -but these foods are also rich in vitamin c. reminder: gout is a metabolic disease in which uric acid crystals precipitate in the joints. -false positive: a test result indicating that a condition is present (positive) when in fact it is not (therefore false). -false negative: a test result indicating that a condition is not present (negative) when in fact it is present (therefore false). -. -c n i c s i d o t o h p . -c n i s o i d u t s a r a l o p take large doses of vitamin c. not surprisingly, side effects of vitamin c supplemen- tation such as nausea, abdominal cramps, and diarrhea are often reported. -several instances of interference with medical regimens are also known. -large amounts of vitamin c excreted in the urine obscure the results of tests used to de- tect diabetes, giving a false positive result in some instances and a false nega- tive in others. -people taking anticlotting medications may unwittingly counteract the effect if they also take massive doses of vitamin c. those with kidney disease, a tendency toward gout, or a genetic abnormality that alters vitamin c s break- down to its excretion products are prone to forming kidney stones if they take large doses of vitamin c.* vitamin c supplements may adversely affect people with iron overload. -(chapter 13 describes the damaging effects of too much iron.) -vitamin c enhances iron absorption and releases iron from body stores; free iron causes the kind of cellular damage typical of free radicals. -these adverse consequences of vi- tamin c s effects on iron have not been seen in clinical studies, but they illustrate how vitamin c can act as a prooxidant when quantities exceed the body s needs.32 the estimated average intake from both diet and supplements is 187 milligrams of vitamin c a day. -few instances warrant consuming more than 200 milligrams a day. -for adults who dose themselves with up to 2 grams a day (and relatively few do), the risks may not be great; those taking more should be aware of the distinct possibility of adverse effects. -vitamin c food sources fruits and vegetables can easily provide a generous amount of vitamin c. a cup of orange juice at breakfast, a salad for lunch, and a stalk of broccoli and a potato for dinner alone provide more than 300 milligrams. -clearly, a person making such food choices needs no vitamin c pills. -figure 10-18 shows the amounts of vitamin c in various common foods. -the overwhelming abundance of purple and green bars reveals not only that the citrus fruits are justly famous for being rich in vitamin c, but that other fruits and vegeta- bles are in the same league. -a half cup of broccoli, bell pepper, or strawberries pro- vides more than 50 milligrams of the vitamin (and an array of other nutrients). -because vitamin c is vulnerable to heat, raw fruits and vegetables usually have a higher nutrient density than their cooked counterparts. -similarly, because vitamin c is readily destroyed by oxygen, foods and juices should be stored properly and consumed within a week of opening.33 the potato is an important source of vitamin c, not because one potato by itself meets the daily need, but because potatoes are such a common staple that they make significant contributions. -in fact, scurvy was unknown in ireland until the potato blight of the mid-1840s when some two million people died of malnutrition and infection. -the lack of yellow, white, brown, and red bars in figure 10-18 confirms that grains, milk (except breast milk), legumes, and meats are notoriously poor sources of vitamin c. organ meats (liver, kidneys, and others) and raw meats contain some vitamin c, but most people don t eat large quantities of these foods. -raw meats and fish contribute enough vitamin c to be significant sources in parts of alaska, canada, and japan, but elsewhere fruits and vegetables are necessary to supply sufficient vitamin c. because of vitamin c s antioxidant property, food manufacturers sometimes add a variation of vitamin c to some beverages and most cured meats, such as luncheon meats, to prevent oxidation and spoilage. -this compound safely pre- serves these foods, but it does not have vitamin c activity in the body. -simply put, ham and bacon cannot replace fruits and vegetables. -see the accompanying table for a summary of vitamin c. * vitamin c is inactivated and degraded by several routes, and sometimes oxalate, which can form kid- ney stones, is produced along the way. -people may also develop oxalate crystals in their kidneys regard- less of vitamin c status. -the water soluble vitamins: b vitamins and vitamin c 355 figure 10-18 vitamin c in selected foods see the how to section on p. 329 for more information on using this figure. -milligrams food serving size (kcalories) 0 10 20 30 40 50 60 70 80 90 bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice banana orange strawberries watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast c (31 kcal) c fresh (22 kcal) 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) c (76 kcal) tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: 1 2 red bell pepper 1 (46 kcal) kiwi 1 2 brussels sprouts c cooked (30 kcal) c raw chopped (20 kcal) rda for men rda for women vitamin c meeting vitamin c needs without fruits (purple) and vegetables (green) is almost impossible. -many of them provide the entire rda in one serving, and others provide at least half. -most meats, legumes, breads, and milk products are poor sources. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie in summary vitamin c other names ascorbic acid rda men: 90 mg/day women: 75 mg/day smokers: (cid:6)35 mg/day upper level adults: 2000 mg/day chief functions in the body collagen synthesis (strengthens blood vessel walls, forms scar tissue, pro- vides matrix for bone growth), antioxidant, thyroxin synthesis, amino acid metabolism, strengthens resistance to infection, helps in absorption of iron significant sources citrus fruits, cabbage-type vegetables (such as brussels sprouts and cauli- flower), dark green vegetables (such as bell peppers and broccoli), cantaloupe, strawberries, lettuce, tomatoes, potatoes, papayas, mangoes easily destroyed by heat and oxygen deficiency disease scurvy deficiency symptoms anemia (small-cell type),a atherosclerotic plaques, pinpoint hemorrhages; bone fragility, joint pain; poor wound healing, frequent infections; bleeding gums, loosened teeth; muscle degeneration and pain, hysteria, depression; rough skin, blotchy bruises toxicity symptoms nausea, abdominal cramps, diarrhea; headache, fatigue, insomnia; hot flashes, rashes; interference with medical tests, aggravation of gout symptoms, urinary tract problems, kidney stonesb asmall-cell type anemia is microcytic anemia. -bpeople with kidney disease, a tendency toward gout, or a genetic abnormality that alters the breakdown of vitamin c are prone to forming kidney stones. -vitamin c is inactivated and de- graded by several routes, sometimes producing oxalate, which can form stones in the kidneys. -356 chapter 10 vita means life. -after this discourse on the vitamins, who could dispute that they deserve their name? -their regulation of metabolic processes makes them vital to the normal growth, development, and maintenance of the body. -the accompany- ing summary table condenses the information provided in this chapter for a quick review. -the remarkable roles of the vitamins continue in the next chapter. -food sources enriched, fortified, or whole- grain products; pork milk products; enriched, forti- fied, or whole-grain products; liver protein-rich foods in summary the water-soluble vitamins vitamin and chief functions deficiency symptoms thiamin part of coenzyme tpp in energy metabolism beriberi (edema or muscle wasting), anorexia and weight loss, neurological disturbances, muscular weakness, heart enlargement and failure toxicity symptoms none reported riboflavin part of coenzymes fad and fmn in energy metabolism niacin part of coenzymes nad and nadp in energy metabolism biotin part of coenzyme in energy metabolism pantothenic acid part of coenzyme a in energy metabolism vitamin b6 part of coenzymes used in amino acid and fatty acid metabolism folate activates vitamin b12; helps synthesize dna for new cell growth vitamin b12 activates folate; helps synthesize dna for new cell growth; protects nerve cells vitamin c synthesis of collagen, carnitine, hormones, neurotransmitters; antioxidant inflammation of the mouth, skin, and eyelids none reported pellagra (diarrhea, dermatitis, and dementia) niacin flush, liver damage, impaired glucose tolerance skin rash, hair loss, neurological disturbances none reported widespread in foods; gi bacteria synthesis digestive and neurological disturbances none reported widespread in foods scaly dermatitis, depression, confusion, convulsions, anemia nerve degeneration, skin lesions protein-rich foods anemia, glossitis, neurological disturbances, elevated homocysteine masks vitamin b12 deficiency legumes, vegetables, fortified grain products anemia; nerve damage and paralysis none reported foods derived from animals scurvy (bleeding gums, pinpoint hemor- rhages, abnormal bone growth, and joint pain) diarrhea, gi distress fruits and vegetables www.thomsonedu.com/thomsonnow nutrition portfolio to obtain all the vitamins you need each day, be sure to select from a variety of foods. -examine your daily choices of whole or enriched grains, dark green leafy vegetables, citrus fruits, and legumes and evaluate their contributions to your vitamin intakes. -if you are a woman of childbearing age, calculate the dietary folate equivalents you receive from folate-rich foods, fortified foods, and supplements and com- pare that to recommended intakes. -compare your vitamin intakes from supplements with their upper levels. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 10, then to nutrition on the net. -search for vitamins at the american dietetic association: www.eatright.org visit the world health organization to learn about vita- min deficiencies around the world: www.who.int learn more about neural tube defects from the spina bifida association of america: www.sbaa.org the water soluble vitamins: b vitamins and vitamin c 357 read about dr. joseph goldberger and his groundbreaking discovery linking pellagra to diet by searching for his name at: www.nih.gov or www.pbs.org learn how fruits and vegetables support a healthy diet rich in vitamins from the national cancer institute or the 5 a day for better health program: www.5aday.gov or 5aday.org nutrition calculations for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 10, then to nutrition calculations. -these problems give you practice in doing simple vitamin- related calculations (answers are provided on p. 359). -be sure to show your calculations for each problem. -1. review the units in which vitamins are measured (a spot check). -a. for each of these vitamins, note the unit of measure: thiamin riboflavin niacin vitamin b6 folate vitamin b12 vitamin c b. recall from the chapter s description of people s self-dosing with vitamin b6 that people who suffer toxicity symptoms may be taking more than 2 grams a day, whereas the rda is less than 2 mil- ligrams. -how much higher than 2 milligrams is 2 grams? -c. vitamin b12 is measured in micrograms. -how many micrograms are in a gram? -how many grams are in a teaspoon of a granular powder? -how many mi- crograms does that represent? -what is your rda for vitamin b12? -this exercise should convince you that the amount of vitamins a person needs is indeed quite small yet still essential. -2. be aware of how niacin intakes are affected by dietary protein availability. -a. refer to the how to on p. 333, and calculate how much niacin a woman receives from a diet that delivers 90 grams protein and 9 milligrams niacin. -(assume her rda for protein is 46 grams/day.) -b. is this woman getting her rda of niacin (14 milligrams ne)? -this exercise should demonstrate that protein helps meet niacin needs. -study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -4. for thiamin, riboflavin, niacin, biotin, pantothenic acid, vitamin b6, folate, vitamin b12, and vitamin c, state: these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -its chief function in the body. -its characteristic deficiency symptoms. -its significant food sources. -(see respective sum- mary tables.) -1. how do the vitamins differ from the energy nutrients? -5. what is the relationship of tryptophan to niacin? -(pp. -323 324) (p. 331) 2. describe some general differences between fat-soluble and water-soluble vitamins. -(pp. -324 326) 3. which b vitamins are involved in energy metabolism? -protein metabolism? -cell division? -(p. 326) 6. describe the relationship between folate and vitamin b12. -(pp. -338 345) 7. what risks are associated with high doses of niacin? -vitamin b6? -vitamin c? -(pp. -332, 336, 353 354) 6. the vitamin that protects against neural tube defects is: a. niacin. -b. folate. -c. riboflavin. -d. vitamin b12. -7. a lack of intrinsic factor may lead to: a. beriberi. -b. pellagra. -c. pernicious anemia. -d. atrophic gastritis. -8. which of the following is a b vitamin? -a. inositol b. carnitine c. vitamin b15 d. pantothenic acid 9. vitamin c serves as a(n): a. coenzyme. -b. antagonist. -c. antioxidant. -d. intrinsic factor. -10. the requirement for vitamin c is highest for: a. smokers. -b. athletes. -c. alcoholics. -d. the elderly. -358 chapter 10 these questions will help you prepare for an exam. -answers can be found on p. 359. -1. vitamins: a. are inorganic compounds. -b. yield energy when broken down. -c. are soluble in either water or fat. -d. perform best when linked in long chains. -2. the rate at and the extent to which a vitamin is absorbed and used in the body is known as its: a. bioavailability. -b. intrinsic factor. -c. physiological effect. -d. pharmacological effect. -3. many of the b vitamins serve as: a. coenzymes. -b. antagonists. -c. antioxidants. -d. serotonin precursors. -4. with respect to thiamin, which of the following is the most nutrient dense? -a. -1 slice whole-wheat bread (69 kcalories and 0.1 milligram thiamin) b. -1 cup yogurt (144 kcalories and 0.1 milligram thi- amin) c. 1 cup snow peas (69 kcalories and 0.22 milligram thiamin) d. 1 chicken breast (141 kcalories and 0.06 milligram thiamin) 5. the body can make niacin from: a. tyrosine. -b. serotonin. -c. carnitine. -d. tryptophan. -references 1. c. s. johnston and j. c. hale, oxidation of ascorbic acid in stored orange juice is associ- ated with reduced plasma vitamin c con- centrations and elevated lipid peroxides, journal of the american dietetic association 105 (2005): 106-109. -2. committee on dietary reference intakes, dietary reference intakes for vitamin c, vita- min e, selenium, and carotenoids (washing- ton, d.c.: national academy press, 2000); committee on dietary reference intakes, dietary reference intakes for thiamin, ri- boflavin, niacin, vitamin b6, folate, vitamin b12, pantothenic acid, biotin, and choline (washington, d.c.: national academy press, 1998). -3. k. j. carpenter, beriberi, white rice, and vitamin b: a disease, a cause, and a cure (berkeley: university of california press, 2000). -4. j. zempleni, uptake, localization, and noncarboxylase roles of biotin, annual review of nutrition 25 (2005): 175-196. -5. r. rodriguez-melendez, j. b. griffin, and j. zempleni, biotin supplementation increases expression of the cytochrome p450 1b1 gene in jurkat cells, increasing the occur- rence of single-stranded dna breaks, journal of nutrition 134 (2004): 2222-2228. -6. s. friso and coauthors, low plasma vitamin b-6 concentrations and modulation of coronary artery disease risk, american journal of clinical nutrition 79 (2004): 992-998. -7. e. aufiero and coauthors, pyridoxine hy- drochloride treatment of carpal tunnel syndrome: a review, nutrition reviews 62 (2004): 96-104; a. a. gerritsen and coau- thors, conservative treatment options for carpal tunnel syndrome: a systematic re- view of randomized controlled trials, journal of neurology 249 (2002): 272-280; r. lu- boshitzky and coauthors, the effect of pyridoxine administration on melatonin secretion in normal men, neuroendocrinology letters 23 (2002): 213-217. -8. a. melse-boonstra and coauthors, bioavail- ability of heptaglutamyl relative to monog- lutamyl folic acid in healthy adults, american journal of clinical nutrition 79 (2004): 424-429. -9. l. b. bailey and r. j. berry, folic acid supple- mentation and the occurrence of congenital heart defects, orofacial clefts, multiple births, and miscarriage, american journal of clinical nutrition 81 (2005): 1213s-1217s. -10. use of dietary supplements containing folic acid among women of childbearing age- united states, 2005, morbidity and mortality weekly report 54 (2005): 955-957. -11. t. tamura and m. f. picciano, folate and human reproduction, american journal of clinical nutrition 83 (2006): 993-1016; spina bifida and anencephaly before and after folic acid mandate united states, 1995- 1996 and 1999-2000, morbidity and mortality weekly report 53 (2004): 362-365. -12. r. l. brent and g. p. oakley, the folate debate, pediatrics 117 (2006): 1418-1419; j. i. rader and b. o. schneeman, prevalence of neural tube defects, folate status, and folate fortification of enriched cereal-grain prod- ucts in the united states, pediatrics 117 (2006): 1394-1399. -13. e. p. quinlivan and j. f. gregory iii, effect of food fortification on folic acid intake in the united states, american journal of clinical nutrition 77 (2003): 221-225. -14. committee on dietary reference intakes, 1998. -15. t. k. eskes, abnormal folate metabolism in mothers with down syndrome offspring: review of the literature, european journal of obstetrics, gynecology, and reproductive biol- ogy 124 (2006): 130-133; j. l. gueant and coauthors, genetic determinants of folate and vitamin b12 metabolism: a common pathway in neural tube defect and down syndrome? -clinical chemistry and laboratory medicine 41 (2003): 1473-1477; n. takamura and coauthors, abnormal folic acid-homo- cysteine metabolism as maternal risk factors for down syndrome in japan, european journal of nutrition 43 (2004): 285-287. -16. h. s. cuckle, primary prevention of down s syndrome, international journal of medical sciences 2 (2005): 93-99; j. g. ray and coau- thors, prevalence of trisomy 21 following folic acid food fortification, american journal of medicinal genetics, part a 120 (2003): 309-313. -17. p. j. baggot and coauthors, a folate-depend- ent metabolite in amniotic fluid from preg- nancies with normal or trisomy 21 chromosomes, fetal diagnosis and therapy 21 (2006): 148-152; n. takamura and coau- thors, abnormal folic acid-homocysteine metabolism as maternal risk factors for down syndrome in japan, european journal of nutrition 43 (2004): 285-287. -18. d. s. wald, m. law, and j. k. morris, homo- cysteine and cardiovascular disease: evi- dence on causality from a meta-analysis, british medical journal 325 (2002): 1202. -19. homocysteine lowering trialists collabora- tion, dose-dependent effects of folic acid on blood concentrations of homocysteine: a meta-analysis of the randomized trials, american journal of clinical nutrition 82 (2005): 806-812; c. m. pfeiffer and coau- thors, biochemical indicators of b vitamin status in the us population after folic acid fortification: results from the national health and nutrition examination survey 1999-2000, american journal of clinical nutrition 82 (2005): 442-450; k. l. tucker and coauthors, breakfast cereal fortified with folic acid, vitamin b-6, and vitamin b- 12 increases vitamin concentrations and reduces homocysteine concentrations: a randomized trial, american journal of clinical nutrition 79 (2004): 805-811; f. v. van oort and coauthors, folic acid and reduction of plasma homocysteine concentrations in older adults: a dose-response study, ameri- can journal of clinical nutrition 77 (2003): 1318-1323; b. j. venn and coauthors, di- the water soluble vitamins: b vitamins and vitamin c 359 etary counseling to increase natural folate intake: a randomized placebo-controlled trial in free-living subjects to assess effects on serum folate and plasma total homocys- teine, american journal of clinical nutrition 76 (2002): 758-765. -20. e. lonn and coauthors, homocysteine lowering with folic acid and b vitamins in vascular disease, new england journal of medicine 354 (2006): 1567-1577. women and the influences of diet, smoking, and alcohol consumption, american journal of clinical nutrition 81 (2005): 669-671. -25. s. p. stabler and r. h. allen, vitamin b12 deficiency as a worldwide problem, annual review of nutrition 24 (2004): 299-326. -26. s. h. zeisel, choline: critical role during fetal development and dietary requirements in adults, annual review of nutrition 26 (2006): 229-250. -21. y. i. kim, 5,10-methylenetetrahydrofolate 27. h. j. powers, riboflavin (vitamin b-2) and reductase polymorphisms and pharmacoge- netics: a new role of single nucleotide polymorphisms in the folate metabolic pathway in human health and disease, nutrition reviews 63 (2005): 398-407; h. j. powers, interaction among folate, riboflavin, genotype, and cancer, with reference to colorectal and cervical cancer, journal of nutrition 135 (2005): 2960s-2966s; d. c. mccabe and m. a. caudill, dna methylation, genomic silencing, and links to nutrition and cancer, nutrition reviews 63 (2005): 183-195; m. e. mart nez, s. m. henning, and d. s. alberts, folate and colorectal neoplasia: relation between plasma and dietary markers of folate and adenoma recurrence, american journal of clinical nutrition 79 (2004): 691-697; g. c. rampersaud, l. b. bailey, and g. p. a. kauwell, relationship of folate to colorectal and cervical cancer: review and recommen- dations for practitioners, journal of the american dietetic association 102 (2002): 1273-1282. -22. a. tjonneland and coauthors, folate intake, alcohol and risk of breast cancer among postmenopausal women in denmark, euro- pean journal of clinical nutrition 60 (2006): 280-286; s. c. larsson and coauthors, folate intake and pancreatic cancer incidence: a prospective study of swedish women and men, journal of the national cancer institute 98 (2006): 407-413; l. baglietto and coau- thors, does dietary folate intake modify effect of alcohol consumption on breast cancer risk? -prospective cohort study, british medical journal 331 (2005): 807-810. -23. m. j. koury and p. ponka, new insights into erythropoiesis: the roles of folate, vitamin b12, and iron, annual review of nutrition 24 (2004): 105-131. -24. k. d. stark and coauthors, status of plasma folate after folic acid fortification of the food supply in pregnant african american health, american journal of clinical nutrition 77 (2003): 1352-1360. -28. j. x. wilson, regulation of vitamin c trans- port, annual review of nutrition 25 (2005): 105-125. -29. b. arroll, non-antibiotic treatments for upper-respiratory tract infections (common cold), respiratory medicine 99 (2005): 1477- 1484; s. sasazuki and coauthors, effect of vitamin c on common cold: randomized controlled trial, european journal of clinical nutrition 24 (2005): 9-17; h. hemil and coauthors, vitamin c, vitamin e, and beta- carotene in relation to common cold inci- dence in male smokers, epidemiology 13 (2002): 32-37; b. takkouche and coauthors, intake of vitamin c and zinc and risk of common cold: a cohort study, epidemiology 13 (2002): 38-44; m. van straten and p. josling, preventing the common cold with a vitamin c supplement: a double-blind, placebo-controlled survey, advances in therapy 19 (2002): 151-159. -30. e. s. wintergerst, s. maggini, and d. h. hornig, immune-enhancing role of vitamin c and zinc and effect on clinical conditions, annals of nutrition and metabolism 50 (2006): 85-94; r. m. douglas, e. b. chalker, and b. treacy, vitamin c for preventing and treat- ing the common cold (cochrane review), cochrane database of systematic reviews 2 (2000): cd000980. -31. committee on dietary reference intakes, 2000. -32. j. n. hathcock and coauthors, vitamins e and c are safe across a broad range of in- takes, american journal of clinical nutrition 81 (2005): 736-745. -33. c. s. johnston and d. l. bowling, stability of ascorbic acid in commercially available orange juices, journal of the american dietetic association 102 (2002): 525-529. answers nutrition calculations 1. a. thiamin: mg riboflavin: mg niacin: mg ne vitamin b6: mg folate: g dfe vitamin b12: g vitamin c: mg b. a thousand times higher (2 g (cid:4) 1000 mg/g (cid:3) 2000 mg; 2. a. she eats 90 g protein. -assume she uses 46 g as protein. -this leaves 90 g (cid:5) 46 g (cid:3) 44 g protein leftover. -44 g protein (cid:2) 100 (cid:3) 0.44 g tryptophan 0.44 g tryptophan (cid:4) 1000 (cid:3) 440 mg tryptophan 440 mg tryptophan (cid:2) 60 (cid:3) 7.3 mg ne 7.3 mg ne (cid:6) 9 mg niacin (cid:3) 16.3 mg ne 2000 mg (cid:2) 2 mg (cid:3) 1000) b. yes c. 1 g (cid:3) 1000 mg; 1 mg (cid:3) 1000 g (1000 (cid:4) 1000 (cid:3) study questions (multiple choice) 1,000,000); 1 million g (cid:3) 1 g 1 tsp (cid:3) 5 g 5 (cid:4) 1,000,000 g (cid:3) 5,000,000 g/tsp see inside front cover for your rda based on age and gender. -1. c 9. c 2. a 3. a 4. c 5. d 6. b 7. c 8. d 10. a highlight 10 vitamin and mineral supplements an estimated 29,000 supplements are cur- rently on the market. -one-third of the popula- tion in the united states takes a vitamin- mineral supplement daily, spending billions of dollars on them each year.1 many people take supplements as dietary insurance in case they are not meeting their nutrient needs from foods alone. -others take supplements as health insurance to protect against certain diseases. -s e g a m i y t t e g / f f l o w - g n u o y d i v a d arguments for supplements vitamin-mineral supplements may be appro- priate in some circumstances. -in some cases, they can prevent or correct deficiencies; in others, they can reduce the risk of diseases. -one out of every five people takes multinutrient pills daily. -others take large doses of single nutrients, most commonly, vita- min c, vitamin e, beta-carotene, iron, and calcium. -in many cases, taking supplements is a costly but harmless practice; some- times, it is both costly and harmful to health. -for the most part, people self-prescribe supplements, taking them on the advice of friends, advertisements, websites, or books that may or may not be reliable. -sometimes, they take supple- ments on the recommendation of a physician. -when such advice follows a valid nutrition assessment, supplementation may be warranted, but even then the preferred course of action is to im- prove food choices and eating habits.2 without an assessment, the advice to take supplements may be inappropriate. -a regis- tered dietitian can help with the decision.3 when people think of supplements, they often think of vita- mins, but minerals are important, too, of course. -people whose diets lack vitamins, for whatever reason, probably lack several minerals as well. -this highlight asks several questions related to vitamin-mineral supplements. -(the accompanying glossary de- fines supplements and related terms.) -what are the arguments for taking supplements? -what are the arguments against taking them? -finally, if people do take supplements, how can they choose the appropriate ones? -(in addition to vitamins and minerals, supplements may also contain amino acids or herbs, which are discussed in chapter 6 and highlight 18, respectively.) -correct overt deficiencies in the united states and canada, adults rarely suffer nutrient defi- ciency diseases such as scurvy, pellagra, and beriberi, but they do still occur. -to correct an overt deficiency disease, a physician may prescribe therapeutic doses two to ten times the rda (or ai) of a nutrient. -at such high doses, the supplement is acting as a drug. -support increased nutrient needs as chapters 15 17 explain, nutrient needs increase during certain stages of life, making it difficult to meet some of those needs with- out supplementation. -for example, women who lose a lot of blood and therefore a lot of iron during menstruation each month may need an iron supplement. -women of childbearing age need folate supplements to reduce the risks of neural tube defects. -similarly, pregnant women and women who are breastfeeding their infants have exceptionally high nutrient needs and so usually need special supplements. -newborns routinely receive a single dose of vitamin k at birth to prevent abnormal bleeding. -infants may need other supplements as well, depending on whether they are breastfed or receiving formula, and on whether their water contains fluoride. -improve nutrition status in contrast to the classical deficiencies, which present a multitude of symptoms and are relatively easy to recognize, subclinical defi- g lossary fda (food and drug adminis- tration): a part of the depart- ment of health and human ser- vices public health service that is responsible for ensuring the safety and wholesomeness of all dietary supplements and food processed and sold in interstate 360 commerce except meat, poultry, and eggs (which are under the jurisdiction of the usda); inspecting food plants and imported foods; and setting standards for food composition and product labeling. -high potency: 100% or more of the daily value for the nutrient in a single supplement and for at least two-thirds of the nutrients in a multinutrient supplement. -supplement: any pill, capsule, tablet, liquid, or powder that contains vitamins, minerals, herbs, or amino acids; intended to increase dietary intake of these substances. -ciencies are subtle and easy to overlook and they are also more likely to occur. -people who do not eat enough food to deliver the needed amounts of nutrients, such as habitual dieters and the elderly, risk developing subclinical deficiencies. -similarly, vegetar- ians who restrict their use of entire food groups without appropri- ate substitutions may fail to fully meet their nutrient needs. -if there is no way for these people to eat enough nutritious foods to meet their needs, then vitamin-mineral supplements may be ap- propriate to help prevent nutrient deficiencies. -improve the body s defenses health care professionals may provide special supplementation to people being treated for addictions to alcohol or other drugs and to people with prolonged illnesses, extensive injuries, or other severe stresses such as surgery.4 illnesses that interfere with appetite, eat- ing, or nutrient absorption impair nutrition status. -for example, the stomach condition atrophic gastritis often creates a vitamin b12 de- ficiency. -in addition, nutrient needs are often heightened by diseases or medications. -in all these cases, supplements are appropriate. -reduce disease risks few people consume the optimal amounts of all the vitamins and minerals by diet alone. -inadequate intakes have been linked to chronic diseases such as heart disease, some cancers, and osteo- porosis.5 for this reason, some physicians recommend that all adults take vitamin-mineral supplements.6 such regular supple- mentation would provide an optimum intake to enhance meta- bolic harmony and prevent disease at relatively little cost.7 others recognize the lack of conclusive evidence and the potential harm of supplementation and advise against such a recommendation.8 the most recent statement from the national institutes of health ac- knowledges that evidence is insufficient to recommend either for or against the use of supplements to prevent chronic diseases.9 highlight 11 reviews the relationships between supplement use and disease prevention. -it describes some of the accumulat- ing evidence suggesting that intakes of certain nutrients at levels much higher than can be attained from foods alone may be ben- eficial in reducing disease risks. -it also presents research confirm- ing the associated risks. -clearly, consumers must be cautious in taking supplements to prevent disease. -many people, especially postmenopausal women and those who are intolerant to lactose or allergic to milk, may not receive enough calcium to forestall the bone degeneration of old age, os- teoporosis. -for them, nonmilk calcium-rich foods are especially valuable, but calcium supplements may also be appropriate. -(highlight 12 provides more details.) -who needs supplements? -in summary, the following list acknowledges that in these specific conditions, these people may need to take supplements: people with specific nutrient deficiencies need specific nutri- ent supplements. -people whose energy intakes are particularly low (fewer than 1600 kcalories per day) need multivitamin and mineral supplements. -vitamin and mineral supplements 361 vegetarians who eat all-plant diets (vegans) and older adults with atrophic gastritis need vitamin b12. -people who have lactose intolerance or milk allergies or who otherwise do not consume enough milk products to forestall extensive bone loss need calcium. -people in certain stages of the life cycle who have increased nutrient requirements need specific nutrient supplements. -(for example, infants need iron and fluoride, women of childbearing age and pregnant women need folate and iron, and the elderly need vitamins b12 and d.) people who have inadequate milk intakes, limited sun expo- sure, or heavily pigmented skin need vitamin d. people who have diseases, infections, or injuries or who have undergone surgery that interferes with the intake, absorption, metabolism, or excretion of nutrients may need specific nutrient supplements. -people taking medications that interfere with the body s use of specific nutrients may need specific nutrient supplements. -except for people in these circumstances, most adults can nor- mally get all the nutrients they need by eating a varied diet of nu- trient-dense foods. -even athletes can meet their nutrient needs without the help of supplements, as chapter 14 explains. -arguments against supplements foods rarely cause nutrient imbalances or toxicities, but supple- ments can. -the higher the dose, the greater the risk of harm. -peo- ple s tolerances for high doses of nutrients vary, just as their risks of deficiencies do. -amounts that some can tolerate may be harm- ful for others, and no one knows who falls where along the spec- trum. -it is difficult to determine just how much of a nutrient is enough or too much. -the tolerable upper intake levels of the dri answer the question how much is too much? -by defining the highest amount that appears safe for most healthy people. -table h10-1 (p. 362) presents these suggested upper levels and daily values for selected vitamins and minerals and the quantities typically found in supplements. -toxicity the extent and severity of supplement toxicity remain unclear. -only a few alert health care professionals can recognize toxicity, even when it is acute. -when it is chronic, with the effects devel- oping subtly and progressing slowly, it often goes unrecognized. -in view of the potential hazards, some authorities believe supple- ments should bear warning labels, advising consumers that large doses may be toxic. -toxic overdoses of vitamins and minerals in children are more readily recognized and, unfortunately, fairly common. -fruit- flavored, chewable vitamins shaped like cartoon characters entice young children to eat them like candy in amounts that can cause poisoning. -high-potency iron supplements (30 milligrams of iron or more per tablet) are especially toxic and are the leading cause 362 highlight 10 table h10-1 vitamin and mineral intakes for adults nutrient vitamins vitamin a vitamin d vitamin e vitamin k thiamin riboflavin niacin (as niacinamide) vitamin b6 folate vitamin b12 pantothenic acid biotin vitamin c choline minerals calcium phosphorus magnesium iron zinc iodine selenium fluoride copper manganese chromium molybdenum tolerable upper intake levelsa daily values typical multivitamin- mineral supplement average single- nutrient supplement 3000 g (10,000 iu) 50 g (2000 iu) 1000 mg (1500 to 2200 iu)b c c c 35 mgb 100 mg 1000 gb c c c 2000 mg 3500 mg 2500 mg 4000 mg 350 mgd 45 mg 40 mg 1100 g 400 g 10 mg 10 mg 11 mg c 2000 g 5000 iu 5000 iu 8000 to 10,000 iu 400 iu 30 iu 80 g 1.5 mg 1.7 mg 20 mg 2 mg 400 g 6 g 10 mg 300 g 60 mg 1000 mg 1000 mg 400 mg 18 mg 15 mg 150 g 70 g 2 mg 2 mg 120 g 75 g 400 iu 30 iu 40 g 1.5 mg 1.7 mg 20 mg 2 mg 400 g 6 g 10 mg 30 g 10 mg 10 mg 160 mg 110 mg 100 mg 18 mg 15 mg 150 g 10 g 0.5 mg 5 mg 25 g 25 g 400 iu 100 to 1000 iu e 50 mg 25 mg 100 to 500 mg 100 to 200 mg 400 g 100 to 1000 g 100 to 500 mg 300 to 600 g 500 to 2000 mg 250 mg 250 to 600 mg e 250 mg 18 to 30 mg 10 to 100 mg e 50 to 200 g e e e 200 to 400 g e aunless otherwise noted, upper levels represent total intakes from food, water, and supplements. -bupper levels represent intakes from supplements, fortified foods, or both. -cthese nutrients have been evaluated by the dri committee for tolerable upper intake levels, but none were established because of insufficient data. -no adverse effects have been reported with intakes of these nutrients at levels typical of supplements, but caution is still advised, given the potential for harm that accompanies excessive intakes. -dupper levels represent intakes from supplements only. -eavailable as a single supplement by prescription. -of accidental ingestion fatalities among children. -even mild over- doses cause gi distress, nausea, and black diarrhea that reflects gastric bleeding. -severe overdoses result in bloody diarrhea, shock, liver damage, coma, and death. -to be truthful and not misleading, but they often fall far short of both. -highlight 18 revisits this topic and includes a discussion of herbal preparations and other alternative therapies. -life-threatening misinformation another problem arises when people who are ill come to believe that high doses of vitamins or minerals can be therapeutic. -not only can high doses be toxic, but the person may take them in- stead of seeking medical help. -furthermore, there are no guaran- tees that the supplements will be effective. -marketing materials for supplements often make health statements that are required unknown needs another argument against the use of supplements is that no one knows exactly how to formulate the ideal supplement. -what nutrients should be included? -which, if any, of the phytochemi- cals should be included? -how much of each? -on whose needs should the choices be based? -surveys have repeatedly shown lit- tle relationship between the supplements people take and the nu- trients they actually need. -false sense of security another argument against supplement use is that it may lull peo- ple into a false sense of security. -a person might eat irresponsibly, thinking, my supplement will cover my needs. -or, experiencing a warning symptom of a disease, a person might postpone seek- ing a diagnosis, thinking, i probably just need a supplement to make this go away. -such self-diagnosis is potentially dangerous. -other invalid reasons other invalid reasons people might use for taking supplements include: the belief that the food supply or soil contains inadequate nutrients the belief that supplements can provide energy the belief that supplements can enhance athletic perfor- mance or build lean body tissues without physical work or faster than work alone (see highlight 14) the belief that supplements will help a person cope with stress the belief that supplements can prevent, treat, or cure con- ditions ranging from the common cold to cancer ironically, people with health problems are more likely to take supplements than other people, yet today s health problems are more likely to be due to overnutrition and poor lifestyle choices than to nutrient deficiencies. -the truth that most people would benefit from improving their eating and exercise habits is harder to swallow than a supplement pill. -bioavailability and antagonistic actions in general, the body absorbs nutrients best from foods in which the nutrients are diluted and dispersed among other substances that may facilitate their absorption. -taken in pure, concentrated form, nutrients are likely to interfere with one another s absorption or with the absorption of nutrients in foods eaten at the same time. -documentation of these effects is particularly extensive for minerals: zinc hinders copper and calcium absorption, iron hinders zinc absorption, calcium hinders magnesium and iron absorption, and magnesium hinders the absorption of calcium and iron. -simi- larly, binding agents in supplements limit mineral absorption. -although minerals provide the most familiar and best- documented examples, interference among vitamins is now be- ing seen as supplement use increases. -the vitamin a precursor beta-carotene, long thought to be nontoxic, interferes with vita- min e metabolism when taken over the long term as a dietary supplement. -vitamin e, on the other hand, antagonizes vitamin k activity and so should not be used by people being treated for blood-clotting disorders. -consumers who want the benefits of optimal absorption of nutrients should eat ordinary foods, se- lected for nutrient density and variety. -whenever the diet is inadequate, the person should first attempt to improve it so as to obtain the needed nutrients from foods. -if that is truly impossible, then the person needs a multivitamin- mineral supplement that supplies between 50 and 150 percent of vitamin and mineral supplements 363 the daily value for each of the nutrients. -these amounts reflect the ranges commonly found in foods and therefore are compati- ble with the body s normal handling of nutrients (its physiologic tolerance). -the next section provides some pointers to assist in the selection of an appropriate supplement. -selection of supplements whenever a physician or registered dietitian recommends a sup- plement, follow the directions carefully. -when selecting a sup- plement yourself, look for a single, balanced vitamin-mineral supplement. -supplements with a usp verification logo have been tested by the u.s. pharmacopeia (usp) to assure that the supplement: contains the declared ingredients and amounts listed on the label does not contain harmful levels of contaminants will disintegrate and release ingredients in the body was made under safe and sanitary conditions if you decide to take a vitamin-mineral supplement, ignore the eye-catching art and meaningless claims. -pay attention to the form the supplements are in, the list of ingredients, and the price. -here s where the truth lies, and from it you can make a rational decision based on facts. -you have two basic questions to answer. -form the first question: what form do you want chewable, liquid, or pills? -if you d rather drink your supplements than chew them, fine. -(if you choose a chewable form, though, be aware that chewable vitamin c can dissolve tooth enamel.) -if you choose pills, look for statements about the disintegration time. -the usp suggests that supplements should completely disintegrate within 30 to 45 minutes. -* obviously, supplements that don t dissolve have little chance of entering the bloodstream, so look for a brand that claims to meet usp disintegration standards. -contents the second question: what vitamins and minerals do you need? -generally, an appropriate supplement provides vitamins and min- erals in amounts that do not exceed recommended intakes. -avoid supplements that, in a daily dose, provide more than the tolera- ble upper intake level for any nutrient. -avoid preparations with more than 10 milligrams of iron per dose, except as prescribed by a physician. -iron is hard to get rid of once it s in the body, and an excess of iron can cause problems, just as a deficiency can (see chapter 13). -misleading claims be aware that organic or natural supplements are no more effective than others and often cost more. -the word synthetic * the usp establishes standards for quality, strength, and purity of supplements. -364 highlight 10 may sound like fake, but to synthesize just means to put together. -they are less expensive, it may be because the price does not have to cover the cost of national advertising. -avoid products that make high potency claims. -more is not better (review the how to on p. 325). -remember that foods are also providing these nutrients. -nutrients can build up and cause unexpected problems. -for example, a man who takes vitamins and begins to lose his hair may think his hair loss means he needs more vitamins, when in fact it may be the early sign of a vitamin a overdose. -(of course, it may be completely unrelated to nutrition as well.) -be wise to fake vitamins and preparations that contain items not needed in human nutrition, such as carnitine and inositol. -such ingredients reveal a marketing strategy aimed at your pocket, not at your health. -the manufacturer wants you to be- lieve that its pills contain the latest new nutrient that other brands omit, but in reality, these substances are not known to be needed by human beings. -realize that the claim that supplements relieve stress is an- other marketing ploy. -if you give even passing thought to what people mean by stress, you ll realize manufacturers could never design a supplement to meet everyone s needs. -is it stressful to take an exam? -well, yes. -is it stressful to survive a major car wreck with third-degree burns and multiple bone fractures? -definitely, yes. -the body s responses to these stresses are different. -the body does use vitamins and minerals in mounting a stress response, but a body fed a well-balanced diet can meet the needs of most minor stresses. -for the major ones, medical intervention is needed. -in any case, taking a vitamin supplement won t make life any less stressful. -other marketing tricks to sidestep are green pills that con- tain dehydrated, crushed parsley, alfalfa, and other fruit and veg- etable extracts. -the nutrients and phytochemicals advertised can be obtained from a serving of vegetables more easily and for less money. -such pills may also provide enzymes, but enzymes are in- activated in the stomach during protein digestion. -be aware that some geriatric tonics are low in vitamins and minerals and may be high in alcohol. -the liquids designed for in- fants offer a more complete option. -recognize the latest nutrition buzzwords. -manufacturers were marketing antioxidant supplements before the print had time to dry on the first scientific reports of antioxidant vitamins action in preventing cancer and cardiovascular disease. -remember, too, that high doses can alter a nutrient s action in the body. -an an- tioxidant in physiological quantities may be beneficial, but in pharmacological quantities, it may act as a prooxidant and pro- duce harmful by-products. -highlight 11 explores antioxidants and supplement use in more detail. -finally, be aware that advertising on the internet is cheap and not closely regulated. -promotional e-mails can be sent to millions of people in an instant. -internet messages can easily cite refer- ences and provide links to other sites, implying an endorsement when in fact none has been given.10 be cautious when examining unsolicited information and search for a balanced perspective. -cost when shopping for supplements, remember that local or store brands may be just as good as nationally advertised brands. -if regulation of supplements the dietary supplement health and education act of 1994 was intended to enable consumers to make informed choices about nutrient supplements. -the act subjects supplements to the same general labeling requirements that apply to foods. -specifically: nutrition labeling for dietary supplements is required. -labels may make nutrient claims (as high or low ) according to specific criteria (for example, an excellent source of vitamin c ). -labels may claim that the lack of a nutrient can cause a deficiency disease, but if they do, they must also include the prevalence of that deficiency disease in the united states. -labels may make health claims that are supported by signifi- cant scientific agreement and are not brand specific (for example, folate protects against neural tube defects ). -labels may claim to diagnose, treat, cure, or relieve com- mon complaints such as menstrual cramps or memory loss, but may not make claims about specific diseases (except as noted above). -labels may make structure-function claims about the role a nutrient plays in the body, how the nutrient performs its function, and how consuming the nutrient is associated with general well-being. -these claims must be accompanied by an fda disclaimer statement: this statement has not been evaluated by the food and drug administration. -this prod- uct is not intended to diagnose, treat, cure or prevent any disease. -figure h10-1 provides an example of a supple- ment label that complies with the requirements. -the multibillion-dollar-a-year supplement industry spends much money and effort influencing these regulations. -the net ef- fect of the dietary supplement health and education act was a deregulation of the supplement industry. -unlike food additives or structure-function claim fda disclaimer structure-function claims do not need fda authorization, but they must be accompanied by a disclaimer. -e i w o d e n n a vitamin and mineral supplements 365 drugs, supplements do not need to be proved safe and effective, nor do they need the fda s approval before being marketed. -fur- thermore, there are no standards for potency or dosage and no requirements for providing warnings of potential side effects. -should a problem arise, the burden falls to the fda to prove that the supplement poses a significant or unreasonable risk of illness or injury. -11 only then would it be removed from the market. -when asked, most americans express support for greater regula- tion of dietary supplements. -health professionals agree.12 if all the nutrients we need can come from food, why not just eat food? -foods have so much more to offer than supplements do. -nutrients in foods come in an infinite variety of combinations with a multitude of different carriers and absorption enhancers. -they come with water, fiber, and an array of beneficial phyto- chemicals. -foods stimulate the gi tract to keep it healthy. -they provide energy, and as long as you need energy each day, why not have nutritious foods deliver it? -foods offer pleasure, satiety, and opportunities for socializing while eating. -in no way can nu- trient supplements hold a candle to foods as a means of meeting human health needs. -for further proof, read highlight 11. figure h10-1 an example of a supplement label product name statement of identity descriptive terms if product meets criteria contents or weight supplement facts panel the suggested dose the name, quantity per tablet, and % daily value for all nutrients listed; nutrients without a daily value may be listed below. -dietary supplement rich in 11 essential vitamins 100 tablets for your protection, do not use if printed foil seal under cap is broken or missing. -directions for use: one tablet daily for adults. -warning: close tightly and keep out of reach of children. -contains iron, which can be harmful or fatal to children in large doses. -in case of accidental overdose, seek professional assistance or contact a poison control center immediately. -store in a dry place at room temperature (59 -86 f). -supplement facts serving size 1 tablet amount per tablet % daily value vitamin a 5000 iu (40% beta carotene) vitamin c 60 mg vitamin d 400 iu vitamin e 30 iu thiamin 1.5 mg riboflavin 1.7 mg niacin 20 mg vitamin b6 2 mg folate 400 mcg vitamin b12 6 mcg biotin 30 mcg pantothenic acid 10 mg calcium 130 mg iron 18 mg phosphorus 100 mg iodine 150 mcg magnesium 100 mg zinc 15 mg selenium 10 mcg copper 2 mg manganese 2.5 mg chromium 10 mcg molybdenum 10 mcg chloride 34 mg potassium 37.5 mg 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 10% 100% 13% 100% 10% 100% 25% 100% 14% 100% 71% 8% 6% 1% 1% ingredients: dicalcium phosphate, magnesium hydroxide, microcrystalline cellulose, potassium chloride, ascorbic acid, ferrous fumarate, modified cellulose gum, zinc sulfate, gelatin, stearic acid, vitamin e acetate, hydroxypropyl methylcellulose, niacinamide, calcium silicate, citric acid, magnesium, stearate, calcium pantothenate, artificial colors (fd&c red no. -40, titanium dioxide, fd&c yellow no. -6 and fd&c blue no. -2), selenium yeast, manganese sulfate, polyethylene glycol, cupric sulfate, molybdenum yeast, chromium yeast, vitamin a acetate, pyridoxine hydrochloride, riboflavin, sodium lauryl sulfate, thiamin mononitrate, beta carotene, folic acid, polysorbate 80, vitamin d, potassium iodide, gluten, biotin, cyanocobalamin. -supplements, inc. 1234 fifth avenue anywhere, usa complete satisfaction or your money back all ingredients must be listed on the label, but not necessarily in the ingredient list nor in descending order of predominance; ingredients named in the nutrition panel need not be repeated here. -name and address of manufacturer nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 10, then to highlights nutrition on the net. -gather information from the office of dietary supple- ments or health canada: dietary-supplements.info .nih.gov or www.hc-sc.gc.ca search for supplements at the american dietetic associ- ation: www.eatright.org learn more about supplements from the fda center for food safety and applied nutrition: www.cfsan.fda.gov/~dms/supplmnt.html obtain consumer information on dietary supplements report adverse reactions associated with dietary supple- from the u.s. pharmacopeia: www.usp.org ments to the fda s medwatch program: www.fda.gov/medwatch review the federal trade commission policies for dietary supplement advertising: www.ftc.gov/bcp/ conline/pubs/buspubs/dietsupp.htm 366 highlight 10 references 1. national institutes of health, multivita- min/mineral supplements and chronic disease prevention, annals of internal medi- cine 145 (2006): 364-371; a. e. millen, k. w. dodd, and a. f. subar, use of vitamin, mineral, nonvitamin, and nonmineral supplements in the united states: the 1987, 1992, and 2000 national health interview survey results, journal of the american di- etetic association 104 (2004): 942-950. -2. position of the american dietetic associa- tion: fortification and nutritional supple- ments, journal of the american dietetic association 105 (2005): 1300-1311. -3. practice paper of the american dietetic association: dietary supplements, journal of the american dietetic association 105 (2005): 460-470; j. r. hunt, tailoring advice on dietary supplements: an opportunity for dietetics professionals, journal of the ameri- can dietetic association 102 (2002): 1754- 1755; c. thomson and coauthors, guidelines regarding the recommendation and sale of dietary supplements, journal of the american dietetic association 102 (2002): 1158-1164. -4. d. e. wildish, an evidence-based approach for dietitian prescription of multiple vita- mins with minerals, journal of the american dietetic association 104 (2004): 779-786. -5. k. m. fairfield and r. h. fletcher, vitamins for chronic disease prevention in adults: scientific review, journal of the american medical association 287 (2002): 3116-3126. -6. r. h. fletcher and k. m. fairfield, vitamins for chronic disease prevention in adults: clinical applications, journal of the american medical association 287 (2002): 3127-3129. -7. b. n. ames, the metabolic tune-up: meta- bolic harmony and disease prevention, journal of nutrition 133 (2003): 1544s-1548s. -8. p.m. kris-etherton and coauthors, antioxi- dant vitamin supplements and cardiovascu- lar disease, circulation 110 (2004): 637-641; c. d. morris and s. carson, routine vitamin supplementation to prevent cardiovascular disease: a summary of the evidence for the u.s. preventive services task force, annals of internal medicine 139 (2003): 56-70; b. hasanain and a. d. mooradian, antioxidant vitamins and their influence in diabetes mellitus, current diabetes reports 2 (2002): 448-456. -9. national institutes of health, 2006. -10. j. m. drazen, inappropriate advertising of dietary supplements, new england journal of medicine 348 (2003): 777-778. -11. institute of medicine and national research council, dietary supplements: a framework for evaluating safety, (washington, d.c.: na- tional academy press, 2004); c. l. taylor, regulatory frameworks for functional foods and dietary supplements, nutrition reviews 62 (2004): 55-59. -12. p. b. fontanarosa, d. rennie, and c. d. deangelis, the need for regulation of di- etary supplements lessons from ephedra, journal of the american medical association 289 (2003): 1568-1570. this page intentionally left blank harald sund/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow figure 11-3: animated! -vitamin a s role in vision figure 11-9: animated! -vitamin d synthesis and activation nutrition portfolio journal realizing that vitamin a from vegetables participates in vision, a mom encourages her children to eat your carrots because they re good for your eyes. -a dad takes his children outside to enjoy the fresh air and sunshine because they need the vitamin d that is made with the help of the sun. -a physician recommends that a patient use vitamin e to slow the progression of nutrition calculations: practice problems heart disease. -another physician gives a newborn a dose of vitamin k to protect against life threatening blood loss. -these common daily occurrences highlight some of the heroic work of the fat-soluble vitamins. -the fat soluble vitamins: a, d, e, and k the fat-soluble vitamins a, d, e, and k differ from the water-soluble vita- mins in several significant ways (review the table on p. 326). -being insolu- ble in the watery gi juices, the fat-soluble vitamins require bile for their absorption. -upon absorption, fat-soluble vitamins travel through the lym- phatic system within chylomicrons before entering the bloodstream, where many of them require protein carriers for transport. -the fat-soluble vita- mins participate in numerous activities throughout the body, but excesses are stored primarily in the liver and adipose tissue. -the body maintains blood concentrations by retrieving these vitamins from storage as needed; thus people can eat less than their daily need for days, weeks, or even months or years without ill effects. -they need only ensure that, over time, average daily intakes approximate recommendations. -by the same token, because fat-soluble vitamins are not readily excreted, the risk of toxicity is greater than it is for the water-soluble vitamins. -vitamin a and beta-carotene vitamin a was the first fat-soluble vitamin to be recognized. -almost a century later, vitamin a and its precursor, beta-carotene, continue to intrigue re- searchers with their diverse roles and profound effects on health. -three different forms of vitamin a are active in the body: retinol, retinal, and retinoic acid. -collectively, these compounds are known as retinoids. -foods derived from animals provide compounds (retinyl esters) that are readily digested and ab- sorbed as retinol in the intestine.1 foods derived from plants provide carotenoids, some of which have vitamin a activity. -* the most studied of the carotenoids is beta-carotene, which can be split to form retinol in the intestine and liver. -beta- carotene s absorption and conversion are significantly less efficient than those of the retinoids.2 figure 11-1 (p. 370) illustrates the structural similarities and differ- ences of these vitamin a compounds and the cleavage of beta-carotene. -the cells can convert retinol and retinal to the other active forms of vitamin a as needed. -the conversion of retinol to retinal is reversible, but the further conversion of * carotenoids with vitamin a activity include alpha-carotene, beta-carotene, and beta-cryptoxanthin; carotenoids with no vitamin a activity include lycopene, lutein, and zeaxanthin. -c h a p t e r 11 chapter outline vitamin a and beta-carotene roles in the body vitamin a deficiency vitamin a toxicity vitamin a recom- mendations vitamin a in foods vitamin d roles in the body vita- min d deficiency vitamin d toxicity vitamin d recommendations and sources vitamin e vitamin e as an antioxidant vitamin e deficiency vitamin e toxi- city vitamin e recommendations vitamin e in foods vitamin k roles in the body vita- min k deficiency vitamin k toxicity vitamin k recommendations and sources the fat-soluble vitamins in summary highlight 11 anitoxidant nutrients in disease prevention a compound that can be converted into an active vitamin is called a precursor. -carotenoids are among the best-known phytochemicals. -vitamin a: all naturally occurring compounds with the biological activity of retinol (ret-ih- nol), the alcohol form of vitamin a. beta-carotene (bay-tah kare-oh-teen): one of the carotenoids; an orange pigment and vitamin a precursor found in plants. -retinoids (ret-ih-noyds): chemically related compounds with biological activity similar to that of retinol; metabolites of retinol. -carotenoids (kah-rot-eh-noyds): pigments commonly found in plants and animals, some of which have vitamin a activity. -the carotenoid with the greatest vitamin a activity is beta-carotene. -vitamin a activity: a term referring to both the active forms of vitamin a and the precursor forms in foods without distinguishing between them. -369 370 chapter 11 figure 11-1 forms of vitamin a in this diagram, corners represent carbon atoms, as in all previous diagrams in this book. -a further simplification here is that methyl groups (ch3) are understood to be at the ends of the lines extending from corners. -(see appendix c for complete structures.) -h c h oh h c o o c oh retinol, the alcohol form retinal, the aldehyde form retinoic acid, the acid form cleavage at this point can yield two molecules of vitamin a* *sometimes cleavage occurs at other points as well, so that one molecule of beta-carotene may yield only one molecule of vitamin a. furthermore, not all beta-carotene is converted to vitamin a, and absorption of beta-carotene is not as efficient as that of vitamin a. for these reasons, 12 g of beta-carotene are equivalent to 1 g of vitamin a. conversion of other carotenoids to vitamin a is even less efficient. -beta-carotene, a precursor retinal to retinoic acid is irreversible (see figure 11-2). -this irreversibility is significant because each form of vitamin a performs a function that the others cannot. -several proteins participate in the digestion and absorption of vitamin a.3 after absorption via the lymph system, vitamin a eventually arrives at the liver, where it is stored. -there, a special transport protein, retinol-binding protein (rbp), picks up vitamin a from the liver and carries it in the blood. -cells that use vitamin a have special protein receptors for it, as if the vitamin were fragile and had to be passed carefully from hand to hand without being dropped. -each form of vitamin a has its own receptor protein (retinol has several) within the cells. -roles in the body vitamin a is a versatile vitamin, known to influence over 500 genes.4 its major roles include: promoting vision participating in protein synthesis and cell differentiation (and thereby main- taining the health of epithelial tissues and skin) supporting reproduction and growth as mentioned, each form of vitamin a performs specific tasks. -retinol supports reproduction and is the major transport and storage form of the vitamin. -retinal is active in vision and is also an intermediate in the conversion of retinol to retinoic acid (review figure 11-2). -retinoic acid acts like a hormone, regulating cell differ- entiation, growth, and embryonic development.5 animals raised on retinoic acid figure 11-2 conversion of vitamin a compounds notice that the conversion from retinol to retinal is reversible, whereas the pathway from retinal to retinoic acid is not. -in foods: retinyl esters (in animal foods) beta carotene (in plant foods) retinol-binding protein (rbp): the specific protein responsible for transporting retinol. -in the body: retinol (supports reproduction) retinal (participates in vision) retinoic acid (regulates growth) the fat-soluble vitamins: a, d, e, and k 371 as their sole source of vitamin a can grow normally, but they become blind because retinoic acid cannot be converted to retinal (review figure 11-2). -vitamin a in vision vitamin a plays two indispensable roles in the eye: it helps maintain a crystal-clear outer window, the cornea, and it participates in the con- version of light energy into nerve impulses at the retina (see figure 11-3 for details). -the cells of the retina contain pigment molecules called rhodopsin; each rhodopsin molecule is composed of a protein called opsin bonded to a molecule of retinal. -when light passes through the cornea of the eye and strikes the cells of the retina, rhodopsin responds by changing shape and becoming bleached. -as it does, the retinal shifts from a cis to a trans configuration, just as fatty acids do during hy- drogenation (see pp. -143 145). -the trans-retinal cannot remain bonded to opsin. -when retinal is released, opsin changes shape, thereby disturbing the membrane of the cell and generating an electrical impulse that travels along the cell s length. -at the other end of the cell, the impulse is transmitted to a nerve cell, which conveys the message to the brain. -much of the retinal is then converted back to its active cis form and combined with the opsin protein to regenerate the pigment rhodopsin. -some reti- nal, however, may be oxidized to retinoic acid, a biochemical dead end for the visual process. -visual activity leads to repeated small losses of retinal, necessitating its con- stant replenishment either directly from foods or indirectly from retinol stores. -vitamin a in protein synthesis and cell differentiation despite its important role in vision, only one-thousandth of the body s vitamin a is in the retina. -much more is in the cells lining the body s surfaces. -there, the vitamin participates in protein synthesis and cell differentiation, a process by which each type of cell develops to perform a specific function. -its role in cell differenti- ation helps explain how vitamin a may prevent cancer.6 all body surfaces, both inside and out, are covered by layers of cells known as ep- ithelial cells. -the epithelial tissue on the outside of the body is, of course, the skin and vitamin a helps to protect against skin damage from sunlight.7 the epithe- lial tissues that line the inside of the body are the mucous membranes: the linings of the mouth, stomach, and intestines; the linings of the lungs and the passages lead- ing to them; the linings of the urinary bladder and urethra; the linings of the uterus and vagina; and the linings of the eyelids and sinus passageways. -within the body, the mucous membranes of the gi tract alone line an area larger than a quarter of a football field, and vitamin a helps to maintain their integrity (see figure 11-4, p. 372). -vitamin a promotes differentiation of epithelial cells and goblet cells, one-celled glands that synthesize and secrete mucus. -mucus coats and protects the epithelial cells from invasive microorganisms and other harmful substances, such as gastric juices. -figure 11-3 animated! -vitamin a s role in vision to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow. -more than 100 million cells reside in the retina, and each contains about 30 million molecules of vitamin a-containing visual pigments. -cornea (kor-nee-uh): the transparent membrane covering the outside of the eye. -retina (ret-in-uh): the layer of light-sensitive nerve cells lining the back of the inside of the eye; consists of rods and cones. -pigment: a molecule capable of absorbing certain wavelengths of light so that it reflects only those that we perceive as a certain color. -rhodopsin (ro-dop-sin): a light-sensitive pigment of the retina; contains the retinal form of vitamin a and the protein opsin. -rhod = red (pigment) opsin = visual protein opsin (op-sin): the protein portion of the visual pigment molecule. -cell differentiation (dif-er-en-she-ay-shun): the process by which immature cells develop specific functions different from those of the original that are characteristic of their mature cell type. -epithelial (ep-i-thee-lee-ul) cells: cells on the surface of the skin and mucous membranes. -epithelial tissue: the layer of the body that serves as a selective barrier between the body s interior and the environment. -(examples are the cornea of the eyes, the skin, the respiratory lining of the lungs, and the lining of the digestive tract.) -mucous (myoo-kus) membranes: the membranes, composed of mucus-secreting cells, that line the surfaces of body tissues. -as light enters the eye, rhodopsin within the cells of the retina absorbs the light. -the cells of the retina contain rhodopsin, a molecule composed of opsin (a protein) and cis-retinal (vitamin a). -light energy cornea retina cells (rods and cones) eye nerve impulses to the brain o c h cis-retinal c o h trans-retinal as rhodopsin absorbs light, retinal changes from cis to trans, which triggers a nerve impulse that carries visual information to the brain. -372 chapter 11 figure 11-4 mucous membrane integrity vitamin a maintains healthy cells in the mucous membranes. -without vitamin a, the normal structure and function of the cells in the mucous membranes are impaired. -mucus goblet cells vitamin a in reproduction and growth as mentioned, vitamin a also sup- ports reproduction and growth. -in men, retinol participates in sperm development, and in women, vitamin a supports normal fetal development during pregnancy. -children lacking vitamin a fail to grow. -when given vitamin a supplements, these children gain weight and grow taller. -the growth of bones illustrates that growth is a complex phenomenon of re- modeling. -to convert a small bone into a large bone, the bone-remodeling cells must undo some parts of the bone as they go, and vitamin a participates in the dismantling. -the cells that break down bone contain sacs of degradative enzymes. -with the help of vitamin a, these enzymes eat away at selected sites in the bone, removing the parts that are not needed. -beta-carotene as an antioxidant in the body, beta-carotene serves primarily as a vitamin a precursor.8 not all dietary beta-carotene is converted to active vita- min a, however. -some beta-carotene may act as an antioxidant capable of pro- tecting the body against disease. -(see highlight 11 for details.) -vitamin a deficiency vitamin a status depends mostly on the adequacy of vitamin a stores, 90 percent of which are in the liver. -vitamin a status also depends on a person s protein status be- cause retinol-binding proteins serve as the vitamin s transport carriers inside the body. -if a person were to stop eating vitamin a containing foods, deficiency symp- toms would not begin to appear until after stores were depleted one to two years for a healthy adult but much sooner for a growing child. -then the consequences would be profound and severe. -vitamin a deficiency is uncommon in the united states, but it is one of the developing world s major nutrition problems. -more than 100 million children worldwide have some degree of vitamin a deficiency and thus are vulnerable to infectious diseases and blindness. -infectious diseases in developing countries around the world, measles is a devastating infectious disease, killing as many as two million children each year. -the severity of the illness often correlates with the degree of vitamin a de- ficiency; deaths are usually due to related infections such as pneumonia and se- vere diarrhea. -providing large doses of vitamin a reduces the risk of dying from these infections. -the world health organization (who) and unicef (the united nations inter- national children s emergency fund) have made the control of vitamin a defi- ciency a major goal in their quest to improve child health and survival throughout the cells that destroy bone during growth are osteoclasts; those that build bone are osteoblasts. -osteo = bone clast = break blast = build the sacs of degradative enzymes are lyso- somes (lye-so-zomes). -key antioxidant nutrients: vitamin c, vitamin e, beta-carotene selenium remodeling: the dismantling and re- formation of a structure, in this case, bone. -figure 11-5 vitamin a deficiency symptom night blindness these photographs illustrate the eyes slow recovery in response to a flash of bright light at night. -in animal research studies, the response rate is measured with electrodes. -the fat-soluble vitamins: a, d, e, and k 373 ) l l a ( e h t y m s e g a m i / r r a f d i v a d in dim light, you can make out the details in this room. -you are using your rods for vision. -a flash of bright light momentarily blinds you as the pigment in the rods is bleached. -you quickly recover and can see the details again in a few seconds. -with inadequate vitamin a, you do not recover but remain blinded for many seconds. -the developing world. -they recommend routine vitamin a supplementation for all children with measles in areas where vitamin a deficiency is a problem or where the measles death rate is high. -in the united states, the american academy of pe- diatrics recommends vitamin a supplementation for certain groups of measles- infected infants and children. -vitamin a supplementation also protects against the complications of other life-threatening infections, including malaria, lung dis- eases, and hiv (human immunodeficiency virus, the virus that causes aids).9 night blindness night blindness is one of the first detectable signs of vitamin a deficiency and permits early diagnosis. -in night blindness, the retina does not re- ceive enough retinal to regenerate the visual pigments bleached by light. -the per- son loses the ability to recover promptly from the temporary blinding that follows a flash of bright light at night or to see after the lights go out. -in many parts of the world, after the sun goes down, vitamin a deficient people become night-blind: children cannot find their shoes or toys, and women cannot fetch water or wash dishes. -they often cling to others or sit still, afraid that they may trip and fall or lose their way if they try to walk alone. -in many developing countries, night blindness due to vitamin a deficiency is so common that the people have special words to de- scribe it. -in indonesia, the term is buta ayam, which means chicken eyes or chicken blindness. -(chickens do not have the cells of the retina that respond to dim light and therefore cannot see at night.) -figure 11-5 shows the eyes slow recov- ery in response to a flash of bright light in night blindness. -blindness (xerophthalmia) beyond night blindness is total blindness failure to see at all. -night blindness is caused by a lack of vitamin a at the back of the eye, the retina; total blindness is caused by a lack at the front of the eye, the cornea. -se- vere vitamin a deficiency is the major cause of childhood blindness in the world, causing more than half a million preschool children to lose their sight each year. -blindness due to vitamin a deficiency, known as xerophthalmia, develops in stages. -at first, the cornea becomes dry and hard, a condition known as xerosis. -then, corneal xerosis can quickly progress to keratomalacia, the softening of the cornea that leads to irreversible blindness. -keratinization elsewhere in the body, vitamin a deficiency affects other surfaces. -on the body s outer surface, the epithelial cells change shape and begin to secrete the protein keratin the hard, inflexible protein of hair and nails. -as figure 11-6 shows, the skin becomes dry, rough, and scaly as lumps of keratin accumulate (keratiniza- tion). -without vitamin a, the goblet cells in the gi tract diminish in number and ac- tivity, limiting the secretion of mucus. -with less mucus, normal digestion and absorption of nutrients falter, and this, in turn, worsens malnutrition by limiting the absorption of whatever nutrients the diet may deliver. -similar changes in the cells of d e t i m i l n u s l a u s i v / r e e r g n e k figure 11-6 vitamin a deficiency symptom the rough skin of keratinization in vitamin a deficiency, the epithelial cells secrete the protein keratin in a process known as keratinization. -(keratinization doesn t occur in the gi tract, but mucus-producing cells dwindle and mucus production declines.) -the extreme of this condition is hyperkeratinization or hyperkeratosis. -when keratin accumulates around hair follicles, the condition is known as follicular hyperkeratosis. -night blindness: slow recovery of vision after flashes of bright light at night or an inability to see in dim light; an early symptom of vitamin a deficiency. -xerophthalmia (zer-off-thal-mee-uh): progressive blindness caused by severe vitamin a deficiency. -xero = dry ophthalm = eye xerosis (zee-row-sis): abnormal drying of the skin and mucous membranes; a sign of vitamin a deficiency. -keratomalacia (kare-ah-toe-ma-lay-shuh): softening of the cornea that leads to irreversible blindness; seen in severe vitamin a deficiency. -keratin (kare-uh-tin): a water-insoluble protein; the normal protein of hair and nails. -keratinization: accumulation of keratin in a tissue; a sign of vitamin a deficiency. -374 chapter 11 multivitamin supplements typically provide: 750 g (2500 iu) 1500 g (5000 iu) for perspective, the rda for vitamin a is 700 g for women and 900 g for men. -for perspective, 10,000 iu 3000 g vitamin a, roughly four times the rda for women. -1 g rae = 1 g retinol = 2 g beta-carotene (supplement) = 12 g beta-carotene (dietary) = 24 g of other vitamin a precursor carotenoids 1 iu retinol = 0.3 g retinol or 0.3 g rae 1 iu beta-carotene (supplement) = 0.5 iu retinol or 0.15 g rae 1 iu beta-carotene (dietary) = 0.165 iu retinol or 0.05 g rae 1 iu other vitamin a precursor carotenoids = 0.025 g rae preformed vitamin a: dietary vitamin a in its active form. -teratogenic (ter-at-oh-jen-ik): causing abnormal fetal development and birth defects. -terato = monster genic = to produce acne: a chronic inflammation of the skin s follicles and oil-producing glands, which leads to an accumulation of oils inside the ducts that surround hairs; usually associated with the maturation of young adults. -retinol activity equivalents (rae): a measure of vitamin a activity; the amount of retinol that the body will derive from a food containing preformed retinol or its precursor beta-carotene. -other epithelial tissues weaken defenses, making infections of the respiratory tract, the gi tract, the urinary tract, the vagina, and possibly the inner ear likely. -vitamin a toxicity just as a deficiency of vitamin a affects all body systems, so does a toxicity. -symp- toms of toxicity begin to develop when all the binding proteins are swamped, and free vitamin a damages the cells. -such effects are unlikely when a person depends on a balanced diet for nutrients, but toxicity is a real possibility when concentrated amounts of preformed vitamin a in foods derived from animals, fortified foods, or supplements is consumed.10 children are most vulnerable to toxicity because they need less vitamin a and are more sensitive to overdoses. -an upper level has been set for preformed vitamin a (see inside front cover). -beta-carotene, which is found in a wide variety of fruits and vegetables, is not converted efficiently enough in the body to cause vitamin a toxicity; instead, it is stored in the fat just under the skin. -although overconsumption of beta-carotene from foods may turn the skin yellow, this is not harmful (see figure 11-7).11 in con- trast, overconsumption of beta-carotene from supplements may be quite harmful. -in excess, this antioxidant may act as a prooxidant, promoting cell division and destroying vitamin a. furthermore, the adverse effects of beta-carotene supple- ments are most evident in people who drink alcohol and smoke cigarettes. -bone defects excessive intake of vitamin a over the years may weaken the bones and contribute to fractures and osteoporosis.12 research findings suggest that most people should not take vitamin a supplements.13 even multivitamin supplements provide more vitamin a than most people need. -birth defects excessive vitamin a poses a teratogenic risk. -high intakes (10,000 iu of supplemental vitamin a daily) before the seventh week of pregnancy appear to be the most damaging. -for this reason, vitamin a is not given as a supplement in the first trimester of pregnancy without specific evidence of deficiency, which is rare. -not for acne adolescents need to know that massive doses of vitamin a have no beneficial effect on acne. -the prescription medicine accutane is made from vitamin a but is chemically different. -taken orally, accutane is effective against the deep le- sions of cystic acne. -it is highly toxic, however, especially during growth, and has caused birth defects in infants when women have taken it during their pregnancies. -for this reason, women taking accutane must begin using two effective forms of contraception at least one month before taking the drug and continue using contra- ception at least one month after discontinuing its use. -they should also refrain from taking any supplements containing vitamin a to avoid additive toxic effects. -another vitamin a relative, retin-a, fights acne, the wrinkles of aging, and other skin disorders. -applied topically, this ointment smooths and softens skin; it also lightens skin that has become darkly pigmented after inflammation. -during treatment, the skin becomes red and tender and peels. -vitamin a recommendations because the body can derive vitamin a from various retinoids and carotenoids, its contents in foods and its recommendations are expressed as retinol activity equivalents (rae). -a microgram of retinol counts as 1 rae, as does 12 micro- grams of dietary beta-carotene. -most food and supplement labels report their vita- min a contents using international units (iu), an old measure of vitamin activity used before direct chemical analysis was possible. -vitamin a in foods the richest sources of the retinoids are foods derived from animals liver, fish liver oils, milk and milk products, butter, and eggs. -because vitamin a is fat soluble, it is the fat-soluble vitamins: a, d, e, and k 375 lost when milk is skimmed. -to compensate, reduced-fat, low-fat, and fat-free milks are often fortified so as to supply 6 to 10 percent of the daily value per cup. -* mar- garine is usually fortified to provide the same amount of vitamin a as butter. -plants contain no retinoids, but many vegetables and some fruits contain vita- min a precursors the carotenoids, red and yellow pigments of plants. -only a few carotenoids have vitamin a activity; the carotenoid with the greatest vitamin a ac- tivity is beta-carotene. -the bioavialability of carotenoids depends in part on fat ac- companying the meal; more carotenoids are absorbed when salads have regular dressing than when reduced-fat dressing is used and essentially no carotenoid ab- sorption occurs when fat-free dressing is used.14 the colors of vitamin a foods the dark leafy greens (like spinach not celery or cabbage) and the rich yellow or deep orange vegetables and fruits (such as win- ter squash, cantaloupe, carrots, and sweet potatoes not corn or bananas) help peo- ple meet their vitamin a needs (see figure 11-8). -a diet including several servings of such carotene-rich sources helps to ensure a sufficient intake. -an attractive meal that includes foods of different colors most likely supplies vi- tamin a as well. -most foods with vitamin a activity are brightly colored green, yellow, orange, and red. -any plant-derived food with significant vitamin a activity must have some color, since beta-carotene is a rich, deep yellow, almost orange * vitamin a fortification of milk in the united states is required to a level found in whole milk (1200 iu per quart), but many manufacturers commonly fortify to a higher level (2000 iu per quart). -simi- larly, in canada all milk that has had fat removed must be fortified with vitamin a. figure 11-8 vitamin a in selected foods see the how to section on p. 329 for more information on using this figure. -symptom of beta- figure 11-7 carotene excess discoloration of the skin y t e i c o s l a c i d e m s t t e s u h c a s s a m 2 0 0 2 the hand on the right shows the skin discoloration that occurs when blood levels of beta-carotene rise in response to a low-kcalorie diet that features carrots, pumpkins, and orange juice. -(the hand on the left belongs to someone else and is shown here for comparison.) -food serving size (kcalories) 0 100 200 300 400 500 600 700 800 900 1000 micrograms rae c (31 kcal) c fresh (22 kcal) bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) banana orange strawberries watermelon milk, fortified yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: beef liver sweet potatoes mango 3 oz fried (184 kcal) 1 2 1 (135 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) c cooked (116 kcal) c (76 kcal) rda for women rda for men vitamin a dark green and deep orange vegetables (green) and fruits (purple) and fortified foods such as milk contribute large quantities of viatmin a. some foods are rich enough in vitamin a to provide the rda and more in a single serving. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie 376 chapter 11 the carotenoids in foods bring colors to meals; the retinoids in our eyes allow us to see them. -chlorophyll (klo-row-fil): the green pigment of plants, which absorbs light and transfers the energy to other molecules, thereby initiating photosynthesis. -xanthophylls (zan-tho-fills): pigments found in plants; responsible for the color changes seen in autumn leaves. -compound. -the beta-carotene in dark green, leafy vegetables is abundant but masked by large amounts of the green pigment chlorophyll. -bright color is not always a sign of vitamin a activity, however. -beets and corn, for example, derive their colors from the red and yellow xanthophylls, which have no vitamin a activity. -as for white plant foods such as potatoes, cauliflower, pasta, and rice, they also offer little or no vitamin a. vitamin a poor fast foods fast foods often lack vitamin a. anyone who dines frequently on hamburgers, french fries, and colas is wise to emphasize colorful veg- etables and fruits at other meals. -. -c n i s o i d u t s a r a l o p vitamin a rich liver people sometimes wonder if eating liver too frequently can cause vitamin a toxicity. -liver is a rich source because vitamin a is stored in the liv- ers of animals, just as in humans. -* arctic explorers who have eaten large quantities of polar bear liver have become ill with symptoms suggesting vitamin a toxicity, as have young children who regularly ate a chicken liver spread that provided three times their daily recommended intake. -liver offers many nutrients, and eating it pe- riodically may improve a person s nutrition status. -but caution is warranted not to eat too much too often, especially for pregnant women. -with one ounce of beef liver providing more than three times the rda for vitamin a, intakes can rise quickly. -in summary vitamin a is found in the body in three forms: retinol, retinal, and retinoic acid. -together, they are essential to vision, healthy epithelial tissues, and growth. -vitamin a deficiency is a major health problem worldwide, leading to infections, blindness, and keratinization. -toxicity can also cause problems and is most often associated with supplement abuse. -animal-derived foods such as liver and whole or fortified milk provide retinoids, whereas brightly colored plant-derived foods such as spinach, carrots, and pumpkins provide beta-carotene and other carotenoids. -in addition to serving as a precursor for vitamin a, beta-carotene may act as an antioxidant in the body. -the accom- panying table summarizes vitamin a s functions in the body, deficiency symp- toms, toxicity symptoms, and food sources. -vitamin a other names retinol, retinal, retinoic acid; precursors are carotenoids such as beta-carotene beta-carotene: spinach and other dark leafy greens; broccoli, deep orange fruits (apricots, cantaloupe) and vegetables (squash, carrots, sweet potatoes, pumpkin) rda men: 900 g rae/day women: 700 g rae/day upper level adults: 3000 g/day chief functions in the body vision; maintenance of cornea, epithelial cells, mucous membranes, skin; bone and tooth growth; reproduction; immunity significant sources retinol: fortified milk, cheese, cream, butter, fortified margarine, eggs, liver deficiency disease hypovitaminosis a deficiency symptoms night blindness, corneal drying (xerosis), triangu- lar gray spots on eye (bitot s spots), softening of the cornea (keratomalacia), and corneal degener- ation and blindness (xerophthalmia); impaired immunity (infectious diseases); plugging of hair follicies with keratin, forming white lumps (hyper- keratosis) toxicity disease hypervitaminosis aa (continued) aa related condition, hypercarotenemia, is caused by the accumulation of too much of the vitamin a precursor beta- carotene in the blood, which turns the skin noticeably yellow. -hypercarotenemia is not, strictly speaking, a toxicity symptom. -* the liver is not the only organ that stores vitamin a. the kidneys, adrenals, and other organs do, too, but the liver stores the most and is the most commonly eaten organ meat. -the fat-soluble vitamins: a, d, e, and k 377 vitamin a (continued) chronic toxicity symptoms acute toxicity symptoms increased activity of osteoclastsb causing reduced bone density; liver abnormalities; birth defects blurred vision, nausea, vomiting, vertigo; in- crease of pressure inside skull, mimicking brain tumor; headaches; muscle incoordination bosteoclasts are the cells that destroy bone during its growth. -those that build bone are osteoblasts. -vitamin d vitamin d (calciferol) is different from all the other nutrients in that the body can synthesize it, with the help of sunlight, from a precursor that the body makes from cholesterol. -therefore, vitamin d is not an essential nutrient; given enough time in the sun, people need no vitamin d from foods. -figure 11-9 diagrams the pathway for making and activating vitamin d. ul- traviolet rays from the sun hit the precursor in the skin and convert it to previt- amin d3. -this compound works its way into the body and slowly, over the next 36 hours, is converted to its active form with the help of the body s heat. -the bi- ological activity of the active vitamin is 500- to 1000-fold greater than that of its precursor. -regardless of whether the body manufactures vitamin d3 or obtains it directly from foods, two hydroxylation reactions must occur before the vitamin becomes fully active.15 first, the liver adds an oh group, and then the kidneys add another oh group to produce the active vitamin. -a review of figure 11-9 reveals how dis- eases affecting either the liver or the kidneys can interfere with the activation of vi- tamin d and produce symptoms of deficiency. -roles in the body though called a vitamin, vitamin d is actually a hormone a compound manufac- tured by one part of the body that causes another part to respond. -like vitamin a, vitamin d has a binding protein that carries it to the target organs most notably, the intestines, the kidneys, and the bones. -all respond to vitamin d by making the minerals needed for bone growth and maintenance available. -vitamin d in bone growth vitamin d is a member of a large and cooperative bone-making and maintenance team composed of nutrients and other com- pounds, including vitamins a, c, and k; hormones (parathyroid hormone and cal- citonin); the protein collagen; and the minerals calcium, phosphorus, magnesium, and fluoride. -vitamin d s special role in bone growth is to maintain blood concen- trations of calcium and phosphorus. -the bones grow denser and stronger as they ab- sorb and deposit these minerals. -vitamin d raises blood concentrations of these minerals in three ways. -it en- hances their absorption from the gi tract, their reabsorption by the kidneys, and their mobilization from the bones into the blood.16 the vitamin may work alone, as it does in the gi tract, or in combination with parathyroid hormone, as it does in the bones and kidneys. -vitamin d is the director, but the star of the show is cal- cium. -details of calcium balance appear in chapter 12. vitamin d in other roles scientists have discovered many other vitamin d tar- get tissues, including cells of the immune system, brain and nervous system, pan- creas, skin, muscles and cartilage, and reproductive organs. -because vitamin d has numerous functions, it may be valuable in treating a number of disorders. -recent ev- idence suggests that vitamin d may protect against tuberculosis, gum inflammation, multiple sclerosis, and some cancers.17 vitamin d comes in many forms, the two most important being a plant version called vitamin d2 or ergocalciferol (er- go-kal-sif-er-ol) and an animal version called vitamin d3 or cholecalciferol (ko-lee-kal-sif-er-ol). -key bone nutrients: vitamin d, vitamin k, vitamin a calcium, phosphorus, magnesium, fluoride figure 11-9 animated! -vitamin d synthesis and activation the precursor of vitamin d is made in the liver from cholesterol (see figure 5- 11 on p. 147 and appendix c). -the acti- vation of vitamin d is a closely regu- lated process. -the final product, active vitamin d, is also known as 1,25-dihy- droxycholecalciferol (or calcitriol). -in the skin: 7-dehydrocholesterol (a precursor made in the liver from cholesterol) ultraviolet light from the sun previtamin d3 foods vitamin d3 (an inactive form) in the liver: hydroxylation 25-hydroxy vitamin d3 in the kidneys: hydroxylation 1,25-dihydroxy vitamin d3 (active form) to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow. -378 chapter 11 because the poorly formed rib attachments resemble rosary beads, this symptom is commonly known as rachitic (ra-kit-ik) rosary ( the rosary of rickets ). -vitamin d deficiency factors that contribute to vitamin d deficiency include dark skin, breastfeeding without supplementation, lack of sunlight, and not using fortified milk. -in vitamin d deficiency, production of the protein that binds calcium in the intestinal cells slows. -thus, even when calcium in the diet is adequate, it passes through the gi tract unabsorbed, leaving the bones undersupplied. -consequently, a vitamin d defi- ciency creates a calcium deficiency and increases the risks of several chronic dis- eases, most notably osteoporosis.18 vitamin d deficient adolescents may not reach their peak bone mass.19 rickets worldwide, the vitamin d deficiency disease rickets still afflicts many children.20 in the united states, rickets is not common, but when it occurs, young, breast-fed, black children are the ones most likely to be affected.21 in rickets, the bones fail to calcify normally, causing growth retardation and skeletal abnormali- ties. -the bones become so weak that they bend when they have to support the body s weight (see figure 11-10). -a child with rickets who is old enough to walk character- istically develops bowed legs, often the most obvious sign of the disease. -another sign is the beaded ribs that result from the poorly formed attachments of the bones to the cartilage. -osteomalacia in adults, the poor mineralization of bone results in the painful bone disease osteomalacia.22 the bones become increasingly soft, flexible, brittle, and deformed. -osteoporosis any failure to synthesize adequate vitamin d or obtain enough from foods sets the stage for a loss of calcium from the bones, which can result in fractures. -highlight 12 describes the many factors that lead to osteoporosis, a condi- tion of reduced bone density. -the elderly vitamin d deficiency is especially likely in older adults for several rea- sons. -for one, the skin, liver, and kidneys lose their capacity to make and activate vi- figure 11-10 vitamin d deficiency symptoms bowed legs and beaded ribs of rickets a t n a l t a f o e r a c h t l a e h s n e r d l i h c t a o h l a v r a c l a m r o n . -r d f o y s e t r u o c o t o h p bowed legs. -in rickets, the poorly formed long bones of the legs bend outward as weight-bearing activities such as walking begin. -beaded ribs. -in rickets, a series of beads develop where the cartilages and bones attach. -. -c n i , s r e h c r a e s e r o t o h p / s e t a i c o s s a o t o h p o i b rickets: the vitamin d deficiency disease in children characterized by inadequate mineralization of bone (manifested in bowed legs or knock-knees, outward-bowed chest, and knobs on ribs). -a rare type of rickets, not caused by vitamin d deficiency, is known as vitamin d refractory rickets. -osteomalacia (os-tee-oh-ma-lay-shuh): a bone disease characterized by softening of the bones. -symptoms include bending of the spine and bowing of the legs. -the disease occurs most often in adult women. -osteo = bone malacia = softening the fat-soluble vitamins: a, d, e, and k 379 tamin d with advancing age. -for another, older adults typically drink little or no milk the main dietary source of vitamin d. and finally, older adults typically spend much of the day indoors, and when they do venture outside, many of them cautiously wear protective clothing or apply sunscreen to all sun-exposed areas of their skin. -dark-skinned people living in northern regions are particularly vulnera- ble.23 all of these factors increase the likelihood of vitamin d deficiency and its con- sequences: bone losses and fractures. -vitamin d supplementation helps to reduce the risks of falls and fractures in elderly persons.24 vitamin d toxicity vitamin d clearly illustrates how nutrients in optimal amounts support health, but both inadequacies and excesses cause trouble. -vitamin d is the most likely of the vitamins to have toxic effects when consumed in excessive amounts. -the amounts of vitamin d made by the skin and found in foods are well within the safe limits set by the upper level, but supplements containing the vitamin in con- centrated form should be kept out of the reach of children and used cautiously, if at all, by adults. -excess vitamin d raises the concentration of blood calcium. -excess blood cal- cium tends to precipitate in the soft tissue, forming stones, especially in the kidneys where calcium is concentrated in the effort to excrete it. -calcification may also harden the blood vessels and is especially dangerous in the major arteries of the heart and lungs, where it can cause death. -vitamin d recommendations and sources only a few foods contain vitamin d naturally. -fortunately, the body can make vita- min d with the help of a little sunshine. -in setting dietary recommendations, how- ever, the dri committee assumed that no vitamin d was available from skin synthesis. -current recommendations may be insufficient, however, given recent re- search showing numerous health benefits and safety of higher intakes.25 vitamin d in foods most adults, especially in sunny regions, need not make spe- cial efforts to obtain vitamin d from food. -people who are not outdoors much or who live in northern or predominantly cloudy or smoggy areas are advised to drink at least 2 cups of vitamin d fortified milk a day. -the fortification of milk with vitamin d is the best guarantee that people will meet their needs and underscores the impor- tance of milk in a well-balanced diet. -* despite vitamin-d fortification, the average intake in the united states falls short of recommendations.26 without adequate sunshine, fortification, or supplementation, a vegan diet can- not meet vitamin d needs. -vegetarians who do not include milk in their diets may use vitamin d fortified soy milk and cereals. -importantly, feeding infants and young children nonfortified health beverages instead of milk or infant formula can create severe nutrient deficiencies, including rickets. -vitamin d from the sun most of the world s population relies on natural expo- sure to sunlight to maintain adequate vitamin d nutrition. -the sun imposes no risk of vitamin d toxicity; prolonged exposure to sunlight degrades the vitamin d pre- cursor in the skin, preventing its conversion to the active vitamin. -even lifeguards on southern beaches are safe from vitamin d toxicity from the sun. -prolonged exposure to sunlight does, however, prematurely wrinkle the skin and present the risk of skin cancer. -sunscreens help reduce these risks, but unfor- tunately, sunscreens with sun protection factors (spf) of 8 and higher also pre- vent vitamin d synthesis. -a strategy to avoid this dilemma is to apply sunscreen after enough time has elapsed to provide sufficient vitamin d synthesis. -for high blood calcium is known as hypercal- cemia and may develop from a variety of disorders, including vitamin d toxicity. -it does not develop from a high calcium intake. -k c o t s r e p u s / z u r c o c s i c n a r f * vitamin d fortification of milk in the united states is 10 micrograms cholecalciferol (400 iu) per quart; in canada, it is 9 to 12 micrograms (350 to 470 iu) per liter, with a current proposal to raise it slightly. -a cold glass of milk refreshes as it replenishes vitamin d and other bone-building nutrients. -380 chapter 11 the sunshine vitamin vitamin d. factors that may limit sun exposure and, therefore, vitamin d synthesis: geographic location season of the year time of day air pollution clothing tall buildings indoor living sunscreens figure 11-11 vitamin d synthesis and latitude above 40 north latitude (and below 40 south latitude in the southern hemi- sphere), vitamin d synthesis essentially ceases for the four months of winter. -synthesis increases as spring approaches, peaks in summer, and declines again in the fall. -people living in regions of extreme northern (or extreme southern) latitudes may miss as much as six months of vitamin d production. -50 50 4040 40 salt lake city chicago new york 4040 40 i s b r o c / a i h p a r g o t o f san francisco denver st. louis washington, d.c. indianapolis 30 30 most people, exposing hands, face, and arms on a clear summer day for 5 to 10 minutes two or three times a week should be sufficient to maintain vitamin d nutrition.27 the pigments of dark skin provide some protection from the sun s damage, but they also reduce vitamin d synthesis. -dark-skinned people require longer sunlight exposure than light-skinned people: heavily pigmented skin achieves the same amount of vitamin d synthesis in three hours as fair skin in 30 minutes. -latitude, season, and time of day also have dramatic effects on vitamin d synthesis (see figure 11-11). -heavy clouds, smoke, or smog block the ultraviolet (uv) rays of the sun that promote vitamin d synthesis. -differences in skin pigmentation, latitude, and smog may account for the finding that african american people, especially those in northern, smoggy cities, are most likely to be vitamin d deficient and de- velop rickets.28 to ensure an adequate vitamin d status, supplements may be needed.29 the body s vitamin d stores from summer synthesis alone are insufficient to meet winter needs.30 dietary guidelines for americans 2005 people with dark skin and those with insufficient exposure to sunlight should consume extra vitamin d from vitamin d-fortified foods and/or supplements. -depending on the radiation used, the uv rays from tanning lamps and tanning beds may also stimulate vitamin d synthesis and increase bone density.31 the po- tential hazards of skin damage, however, may outweigh any possible benefits. -* the food and drug administration (fda) warns that if the lamps are not properly fil- tered, people using tanning booths risk burns, damage to the eyes and blood ves- sels, and skin cancer. -* the best wavelengths for vitamin d synthesis are uv-b rays between 290 and 310 nanometers. -some tanning parlors advertise uv-a rays only, for a tan without the burn, but uv-a rays can damage the skin. -the fat-soluble vitamins: a, d, e, and k 381 in summary vitamin d can be synthesized in the body with the help of sunlight or obtained from fortified milk. -it sends signals to three primary target sites: the gi tract to absorb more calcium and phosphorus, the bones to release more, and the kid- neys to retain more. -these actions maintain blood calcium concentrations and support bone formation. -a deficiency causes rickets in childhood and osteoma- lacia in later life. -the table below summarizes vitamin d facts. -vitamin d other names calciferol (kal-sif-er-ol), 1,25-dihydroxy vita- min d (calcitriol); the animal version is vitamin d3 or cholecalciferol; the plant version is vitamin d2 or ergocalciferol; precursor is the body s own cholesterol adequate intake (ai) adults: 5 g/day (19 50 yr) 10 g/day (51 70 yr) 15 g/day (>70 yr) upper level adults: 50 g/day chief functions in the body mineralization of bones (raises blood calcium and phosphorus by increasing absorption from digestive tract, withdrawing calcium from bones, stimulating retention by kidneys) significant sources synthesized in the body with the help of sunlight; fortified milk, margarine, butter, juices, cereals, and chocolate mixes; veal, beef, egg yolks, liver, fatty fish (herring, salmon, sardines) and their oils deficiency symptoms rickets in children inadequate calcification, resulting in misshapen bones (bowing of legs); enlargement of ends of long bones (knees, wrists); deformities of ribs (bowed, with beads or knobs);a delayed closing of fontanel, resulting in rapid enlarge- ment of head (see figure below); lax muscles resulting in protrusion of abdomen; muscle spasms osteomalacia or osteoporosis in adults loss of calcium, resulting in soft, flexible, brittle, and deformed bones; progressive weakness; pain in pelvis, lower back, and legs toxicity disease hypervitaminosis d toxicity symptoms elevated blood calcium; calcification of soft tissues (blood vessels, kidneys, heart, lungs, tisues around joints) fontanel a fontanel is an open space in the top of a baby s skull before the bones have grown together. -in rickets, closing of the fontanel is delayed. -fpo anterior fontanel normally closes by the end of the second year. -posterior fontanel normally closes by the end of the first year. -abowing of the ribs causes the symptoms known as pigeon breast. -the beads that form on the ribs resemble rosary beads; thus this symptom is known as rachitic (ra-kit-ik) rosary ( the rosary of rickets ). -vitamin e researchers discovered a component of vegetable oils necessary for reproduction in rats and named this antisterility factor tocopherol, which means to bring forth offspring. -when chemists isolated four different tocopherol compounds, they desig- nated them by the first four letters of the greek alphabet: alpha, beta, gamma, and delta. -the tocopherols consist of a complex ring structure and a long saturated side chain. -(appendix c provides the chemical structures.) -the positions of methyl tocopherol (tuh-koff-er-ol): a general term for several chemically related compounds, one of which has vitamin e activity. -(see appendix c for chemical structures.) -382 chapter 11 key antioxidant nutrients: vitamin c, vitamin e, beta-carotene selenium alpha-tocopherol: the active vitamin e compound. -erythrocyte (eh-rith-ro-cite) hemolysis (he-moll-uh-sis): the breaking open of red blood cells (erythrocytes); a symptom of vitamin e deficiency disease in human beings. -erythro = red cyte = cell hemo = blood lysis = breaking hemolytic (he-moh-lit-ick) anemia: the condition of having too few red blood cells as a result of erythrocyte hemolysis. -muscular dystrophy (dis-tro-fee): a hereditary disease in which the muscles gradually weaken. -its most debilitating effects arise in the lungs. -fibrocystic (fye-bro-sis-tik) breast disease: a harmless condition in which the breasts develop lumps, sometimes associated with caffeine consumption. -in some, it responds to abstinence from caffeine; in others, it can be treated with vitamin e. fibro = fibrous tissue cyst = closed sac intermittent claudication (klaw-dih-kay- shun): severe calf pain caused by inadequate blood supply. -it occurs when walking and subsides during rest. -intermittent = at intervals claudicare = to limp groups (ch3) on the side chain and their chemical rotations distinguish one toco- pherol from another. -alpha-tocopherol is the only one with vitamin e activity in the human body.32 the other tocopherols are not readily converted to alpha- tocopherol in the body, nor do they perform the same roles. -whether these other to- copherols might be beneficial in other ways is the subject of current research.33 vitamin e as an antioxidant vitamin e is a fat-soluble antioxidant and one of the body s primary defenders against the adverse effects of free radicals. -its main action is to stop the chain reac- tion of free radicals producing more free radicals (see highlight 11). -in doing so, vi- tamin e protects the vulnerable components of the cells and their membranes from destruction. -most notably, vitamin e prevents the oxidation of the polyunsaturated fatty acids, but it protects other lipids and related compounds (for example, vitamin a) as well. -accumulating evidence suggests that vitamin e may reduce the risk of heart dis- ease by protecting low-density lipoproteins (ldl) against oxidation and reducing inflammation.34 the oxidation of ldl and inflammation have been implicated as key factors in the development of heart disease. -highlight 11 provides many more details on how vitamin e and other antioxidants protect against chronic diseases, such as heart disease and cancer. -vitamin e deficiency in human beings, a primary deficiency of vitamin e (from poor dietary intake) is rare; deficiency is usually associated with diseases of fat malabsorption such as cys- tic fibrosis. -without vitamin e, the red blood cells break open and spill their con- tents, probably due to oxidation of the polyunsaturated fatty acids in their membranes. -this classic sign of vitamin e deficiency, known as erythrocyte he- molysis, is seen in premature infants, born before the transfer of vitamin e from the mother to the infant that takes place in the last weeks of pregnancy. -vitamin e treat- ment corrects hemolytic anemia. -prolonged vitamin e deficiency also causes neuromuscular dysfunction involv- ing the spinal cord and retina of the eye. -common symptoms include loss of mus- cle coordination and reflexes and impaired vision and speech. -vitamin e treatment corrects these neurological symptoms of vitamin e deficiency, but it does not prevent or cure the hereditary muscular dystrophy that afflicts young children. -two other conditions seem to respond to vitamin e treatment, although results are inconsistent. -one is a nonmalignant breast disease (fibrocystic breast dis- ease), and the other is an abnormality of blood flow that causes cramping in the legs (intermittent claudication). -vitamin e toxicity vitamin e supplement use has risen in recent years as its protective actions against chronic diseases have been recognized. -still, toxicity is rare, and it appears safe across a broad range of intakes.35 the upper level for vitamin e (1000 milligrams) is more than 65 times greater than the recommended intake for adults (15 mil- ligrams). -extremely high doses of vitamin e may interfere with the blood-clotting ac- tion of vitamin k and enhance the effects of drugs used to oppose blood clotting, causing hemorrhage. -vitamin e recommendations the current rda for vitamin e is based on the alpha-tocopherol form only. -as men- tioned earlier, the other tocopherols cannot be converted to alpha-tocopherol, nor the fat-soluble vitamins: a, d, e, and k 383 e r o o m . -m g i a r c fat-soluble vitamin e is found predominantly in vegetable oils, seeds, and nuts. -appendix h accurately presents vitamin e data in milligrams of alpha-tocopherol. -can they perform the same metabolic roles in the body. -a person who consumes large quantities of polyunsaturated fatty acids needs more vitamin e. fortu- nately, vitamin e and polyunsaturated fatty acids tend to occur together in the same foods. -current research suggests that most adults in the united states fall short of recommended intakes for vitamin e and that smokers may have a higher requirement.36 vitamin e in foods vitamin e is widespread in foods. -much of the vitamin e in the diet comes from veg- etable oils and products made from them, such as margarine and salad dressings. -wheat germ oil is especially rich in vitamin e. because vitamin e is readily destroyed by heat processing (such as deep-fat fry- ing) and oxidation, fresh or lightly processed foods are preferable sources. -most processed and convenience foods do not contribute enough vitamin e to ensure an adequate intake. -prior to 2000, values of the vitamin e in foods reflected all of the tocopherols and were expressed in milligrams of tocopherol equivalents. -these measures over- estimated the amount of alpha-tocopherol. -to estimate the alpha-tocopherol con- tent of foods stated in tocopherol equivalents, multiply by 0.8.37 in summary vitamin e acts as an antioxidant, defending lipids and other components of the cells against oxidative damage. -deficiencies are rare, but they do occur in premature infants, the primary symptom being erythrocyte hemolysis. -vita- min e is found predominantly in vegetable oils and appears to be one of the least toxic of the fat-soluble vitamins. -the summary table reviews vitamin e s functions, deficiency symptoms, toxicity symptoms, and food sources. -significant sources polyunsaturated plant oils (margarine, salad dressings, shortenings), leafy green vegetables, wheat germ, whole grains, liver, egg yolks, nuts, seeds, fatty meats easily destroyed by heat and oxygen deficiency symptoms red blood cell breakage,a nerve damage toxicity symptoms augments the effects of anticlotting medication vitamin e other names alpha-tocopherol rda adults: 15 mg/day upper level adults: 1000 mg/day chief functions in the body antioxidant (stabilization of cell membranes, regulation of oxidation reactions, protection of polyunsaturated fatty acids [pufa] and vitamin a) athe breaking of red blood cells is called erythrocyte hemolysis. -vitamin k like vitamin d, vitamin k can be obtained from a nonfood source. -bacteria in the gi tract synthesize vitamin k that the body can absorb. -vitamin k acts primarily in blood clotting, where its presence can make the difference between life and death. -blood has a remarkable ability to remain liquid, but it can turn solid within seconds k stands for the danish word koagulation ( coagulation or clotting ). -384 chapter 11 soon after birth, newborn infants receive a dose of vitamin k to prevent hemorrhagic disease. -hemophilia is caused by a genetic defect and has no relation to vitamin k. reminder: a primary deficiency develops in response to an inadequate dietary intake whereas a secondary deficiency occurs for other reasons. -hemorrhagic (hem-oh-raj-ik) disease: a disease characterized by excessive bleeding. -hemophilia (he-moh-feel-ee-ah): a hereditary disease in which the blood is unable to clot because it lacks the ability to synthesize certain clotting factors. -sterile: free of microorganisms, such as bacteria. -when the integrity of that system is disturbed. -(if blood did not clot, a single pinprick could drain the entire body of all its blood.) -. -c n i , s r e h c r a e s e r o t o h p / r e s a r f i n o m s roles in the body more than a dozen different proteins and the mineral calcium are involved in mak- ing a blood clot. -vitamin k is essential for the activation of several of these proteins, among them prothrombin, made by the liver as a precursor of the protein thrombin (see figure 11-12). -when any of the blood-clotting factors is lacking, hemorrhagic disease results. -if an artery or vein is cut or broken, bleeding goes unchecked. -(of course, this is not to say that hemorrhaging is always caused by vitamin k defi- ciency. -another cause is the hereditary disorder hemophilia, which is not cur- able with vitamin k.) vitamin k also participates in the synthesis of bone proteins. -without vitamin k, the bones produce an abnormal protein that cannot bind to the minerals that nor- mally form bones, resulting in low bone density.38 an adequate intake of vitamin k helps to make the bone protein correctly, decreases bone turnover, and protects against hip fractures.39 vitamin k is historically known for its role in blood clotting, and more recently for its participation in bone building, but researchers continue to discover proteins needing vitamin k s assistance.40 these proteins have been identified in the plaques of atherosclerosis, the kidneys, and the nervous system. -vitamin k deficiency a primary deficiency of vitamin k is rare, but a secondary deficiency may occur in two circumstances. -first, whenever fat absorption falters, as occurs when bile pro- duction fails, vitamin k absorption diminishes. -second, some drugs disrupt vitamin k s synthesis and action in the body: antibiotics kill the vitamin k producing bacte- ria in the intestine, and anticoagulant drugs interfere with vitamin k metabolism and activity. -when vitamin k deficiency does occur, it can be fatal. -newborn infants present a unique case of vitamin k nutrition because they are born with a sterile intestinal tract, and the vitamin k producing bacteria take weeks to establish themselves. -at the same time, plasma prothrombin concentra- tions are low. -(this reduces the likelihood of fatal blood clotting during the stress of figure 11-12 blood-clotting process when blood is exposed to air, foreign substances, or secretions from injured tis- sues, platelets (small, cell-like structures in the blood) release a phospholipid known as thromboplastin. -thromboplastin catalyzes the conversion of the inac- tive protein prothrombin to the active enzyme thrombin. -thrombin then cat- alyzes the conversion of the precursor protein fibrinogen to the active protein fib- rin that forms the clot. -vitamin k calcium and thromboplastin (a phospholipid) from blood platelets fibrinogen (a soluble protein) several precursors earlier in the series depend on vitamin k prothrombin (an inactive protein) thrombin (an active enzyme) fibrin (a solid clot) the fat-soluble vitamins: a, d, e, and k 385 the natural form of vitamin k is phyllo- quinone (fill-oh-kwin-own); the syn- thetic form is menadione (men-uh-dye- own). -see appendix c for the chemistry of these structures. -o i g g u r r a f w e h t t a m notable food sources of vitamin k include green vegetables such as collards, spinach, bib lettuce, brussels sprouts, and cabbage and veg- etable oils such as soybean oil and canola oil. -birth.) -to prevent hemorrhagic disease in the newborn, a single dose of vitamin k (usually as the naturally occurring form, phylloquinone) is given at birth either orally or by intramuscular injection. -concerns that vitamin k given at birth raises the risks of childhood cancer are unproved and unlikely. -vitamin k toxicity toxicity is not common, and no adverse effects have been reported with high intakes of vitamin k. therefore, an upper level has not been established. -high doses of vi- tamin k can reduce the effectiveness of anticoagulant drugs used to prevent blood clotting.41 people taking these drugs should eat vitamin k rich foods in moderation and keep their intakes consistent from day to day. -vitamin k recommendations and sources as mentioned earlier, vitamin k is made in the gi tract by the billions of bacteria that normally reside there. -once synthesized, vitamin k is absorbed and stored in the liver. -this source provides only about half of a person s needs. -vitamin k rich foods such as green vegetables and vegetable oils can easily supply the rest. -in summary vitamin k helps with blood clotting, and its deficiency causes hemorrhagic dis- ease (uncontrolled bleeding). -bacteria in the gi tract can make the vitamin; people typically receive about half of their requirements from bacterial synthe- sis and half from foods such as green vegetables and vegetable oils. -because people depend on bacterial synthesis for vitamin k, deficiency is most likely in newborn infants and in people taking antibiotics. -the accompanying table provides a summary of vitamin k facts. -vitamin k other names phylloquinone, menaquinone, menadione, naphthoquinone adequate intakes (ai) men: 120 g/day women: 90 g/day chief functions in the body synthesis of blood-clotting proteins and bone proteins significant sources bacterial synthesis in the digestive tract;a liver; leafy green vegetables, cabbage-type vegetables; milk deficiency symptoms hemorrhaging toxicity symptoms none known avitamin k needs cannot be met from bacterial synthesis alone; however, it is a potentially important source in the small intestine, where absorption efficiency ranges from 40 to 70 percent. -the fat-soluble vitamins in summary the four fat-soluble vitamins play many specific roles in the growth and mainte- nance of the body. -their presence affects the health and function of the eyes, skin, gi tract, lungs, bones, teeth, nervous system, and blood; their deficiencies become apparent in these same areas. -toxicities of the fat-soluble vitamins are possible, especially when people use supplements, because the body stores excesses. -386 chapter 11 as with the water-soluble vitamins, the function of one fat-soluble vitamin often depends on the presence of another. -recall that vitamin e protects vitamin a from oxidation. -in vitamin e deficiency, vitamin a absorption and storage are impaired. -three of the four fat-soluble vitamins a, d, and k play important roles in bone growth and remodeling. -as mentioned, vitamin k helps synthesize a specific bone protein, and vitamin d regulates that synthesis. -vitamin a, in turn, may control which bone-building genes respond to vitamin d. fat-soluble vitamins also interact with minerals. -vitamin d and calcium coop- erate in bone formation, and zinc is required for the synthesis of vitamin a s trans- port protein, retinol-binding protein. -zinc also assists the enzyme that regenerates retinal from retinol in the eye. -the roles of the fat-soluble vitamins differ from those of the water-soluble vitamins, and they appear in different foods yet they are just as essential to life. -the need for them underlines the importance of eating a wide variety of nourishing foods daily. -the following table condenses the information on fat-soluble vitamins into a short summary. -in summary the fat-soluble vitamins vitamin and chief functions vitamin a vision; maintenance of cornea, epithelial cells, mucous membranes, skin; bone and tooth growth; reproduction; immunity vitamin d mineralization of bones (raises blood calcium and phosphorus by increasing absorption from digestive tract, withdrawing calcium from bones, stimulating retention by kidneys) vitamin e antioxidant (stabilization of cell membranes, regulation of oxidation reactions, protection of polyunsaturated fatty acids [pufa] and vitamin a) vitamin k synthesis of blood-clotting proteins and bone proteins deficiency symptoms toxicity symptoms significant sources infectious diseases, night blindness, blindness (xerophthalmia), keratinization reduced bone mineral density, liver abnormalities, birth defects retinol: milk and milk products beta-carotene: dark green leafy and deep yellow/orange vegetables rickets, osteomalacia calcium imbalance (calcification of soft tisues and formation of stones) synthesized in the body with the help of sunshine; fortified milk erythrocyte hemolysis, nerve damage hemorrhagic effects vegetable oils hemorrhage none known synthesized in the body by gi bacteria; green leafy vegetables www.thomsonedu.com/thomsonnow nutrition portfolio for the fat-soluble vitamins, select colorful fruits and vegetables, fortified milk or soy products, and vegetable oils; use supplements with caution, if at all. -examine your weekly choices of vegetables and evaluate whether you meet the recommendations for dark green or orange and deep yellow vegetables. -consider whether you drink enough vitamin d-fortified milk or go outside in the sunshine regularly. -describe the vegetable oils you use when you cook and their vitamin contributions. -the fat-soluble vitamins: a, d, e, and k 387 nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 11, then to nutrition on the net. -search for vitamins at the american dietetic associa- tion: www.eatright.org review the dietary reference intakes for vitamins a, d, e, and k and the carotenoids by searching for dri : www.nap.edu visit the world health organization to learn about vita- min deficiencies around the world: www.who.int search for vitamins at the u.s. government health in- formation site: www.healthfinder.gov learn how fruits and vegetables support a healthy diet rich in vitamins from the 5 a day for better health pro- gram: www.5aday.com or www.5aday.gov nutrition calculations for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 11, then to nutrition calculations. -these exercises will help you learn the best food sources for the vitamins and prepare you to examine your own food choices. -see p. 389 for answers. -1. review the units in which vitamins are measured (a spot check). -for each of these vitamins, note the unit of measure: vitamin a vitamin e vitamin d vitamin k 2. analyze the vitamin contents of foods. -review the fig- ures, photos, and food sources sections in chapters 10 and 11 and list the food group(s) that contributed the most of each vitamin. -which food groups offer the most thiamin? -the most riboflavin? -the most niacin? -the most vitamin b6? -the most folate? -the most vitamin b12? -the most vitamin c? -the most vitamin a? -the most vitamin d? -the most vitamin e? -list the groups that provide the most and compare them with the usda food guide in chapter 2. this exercise should convince you that each of the food groups provides some, but not all, of the vitamins needed daily. -for a full array, a person needs to eat a variety of foods from each of the food groups regularly. -study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -5. describe vitamin e s role as an antioxidant. -what are the chief symptoms of vitamin e deficiency? -(p. 382) these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. list the fat-soluble vitamins. -what characteristics do they have in common? -how do they differ from the water-soluble vitamins? -(p. 369) 2. summarize the roles of vitamin a and the symptoms of its deficiency. -(pp. -370 374) 3. what are vitamin precursors? -name the precursors of vitamin a, and tell in what classes of foods they are located. -give examples of foods with high vitamin a activity. -(pp. -369, 374 376) 4. how is vitamin d unique among the vitamins? -what is its chief function? -what are the richest sources of this vitamin? -(pp. -377, 379 380) 6. what is vitamin k s primary role in the body? -what con- ditions may lead to vitamin k deficiency? -(pp. -384 385) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 389. -1. fat-soluble vitamins: a. are easily excreted. -b. seldom reach toxic levels. -c. require bile for absorption. -d. are not stored in the body s tissues. -2. the form of vitamin a active in vision is: a. retinal. -b. retinol. -c. rhodopsin. -d. retinoic acid. -388 chapter 11 3. vitamin a deficiency symptoms include: 7. vitamin e s most notable role is to: a. rickets and osteomalacia. -b. hemorrhaging and jaundice. -c. night blindness and keratomalacia. -d. fibrocystic breast disease and erythrocyte hemolysis. -a. protect lipids against oxidation. -b. activate blood-clotting proteins. -c. support protein and dna synthesis. -d. enhance calcium deposits in the bones. -4. good sources of vitamin a include: 8. the classic sign of vitamin e deficiency is: a. oatmeal, pinto beans, and ham. -b. apricots, turnip greens, and liver. -c. whole-wheat bread, green peas, and tuna. -d. corn, grapefruit juice, and sunflower seeds. -a. rickets. -b. xeropthalmia. -c. muscular dystrophy. -d. erythrocyte hemolysis. -5. to keep minerals available in the blood, vitamin d targets: 9. without vitamin k: a. the skin, the muscles, and the bones. -b. the kidneys, the liver, and the bones. -c. the intestines, the kidneys, and the bones. -d. the intestines, the pancreas, and the liver. -a. muscles atrophy. -b. bones become soft. -c. skin rashes develop. -d. blood fails to clot. -6. vitamin d can be synthesized from a precursor that the 10. a significant amount of vitamin k comes from: body makes from: a. bilirubin. -b. tocopherol. -c. cholesterol. -d. beta-carotene. -references a. vegetable oils. -b. sunlight exposure. -c. bacterial synthesis. -d. fortified grain products. -1. e. h. harrison, mechanisms of digestion and absorption of dietary vitamin a, annual review of nutrition 25 (2005): 87-103. -2. s. j. hickenbottom and coauthors, variabil- ity in conversion of -carotene to vitamin a in men as measured by using a double-tracer study design, american journal of clinical nutrition 75 (2002): 900-907; k. j. yeum and r. m. russell, carotenoid bioavailability and bioconversion, annual review of nutrition 22 (2002): 483-504. -3. e. h. harrison, mechanisms of digestion and absorption of dietary vitamin a, annual review of nutrition 25 (2005): 87-103. -4. j. bastien and c. rochette-egly, nuclear retinoid receptors and the transcription of retinoid-target genes, gene 328 (2004): 1-16; j. e. balmer and r. blomhoff, gene expres- sion regulation by retinoic acid, journal of lipid research 43 (2002): 1773-1808. -5. m. clagett-dame and h. f. deluca, the role of vitamin a in mammalian reproduction and embryonic development, annual review of nutrition 22 (2002): 347-381. -6. t. oren, j. a. sher, and t. evans, hematopoiesis and retinoids: development and disease, leukemia lymphoma 44 (2003): 1881-1891; a. c. ross, advances in retinoid research: mechanisms of cancer chemopre- vention symposium introduction, journal of nutrition 133 (2003): 271s-272s. -7. h. sies and w. stahl, nutritional protection against skin damage from sunlight, annual review of nutrition 24 (2004): 173-200. -8. committee on dietary reference intakes, dietary reference intakes for vitamin c, vitamin e, selenium, and carotenoids (wash- ington, d.c.: national academy press, 2000). -9. e. villamor and coauthors, vitamin a supplements ameliorate the adverse effect of hiv-1, malaria, and diarrheal infections on child growth, pediatrics 109 (2002): e6. -10. k. l. penniston and s. a. tanumihardjo, the acute and chonic toxic effects of vita- min a, american journal of clinical nutrition 83 (2006): 191-201. -11. a. mazzone and a. dal canton, images in clinical medicine hypercarotenemia, new england journal of medicine 346 (2002): 821. -12. p. s. genaro and l. a. martini, vitamin a supplementation and risk of skeletal frac- ture, nutrition reviews 62 (2004): 65-72; p. lips, hypervitaminosis a and fractures, new england journal of medicine 348 (2003): 347- 349; k. micha lsson and coauthors, serum retinol levels and the risk of fracture, new england journal of medicine 348 (2003): 287-294; d. feskanich and coauthors, vita- min a intake and hip fractures among post- menopausal women, journal of the american medical association 287 (2002): 47-54. -13. h. a. jackson and a. h. sheehan, effect of vitamin a on fracture risk, the annals of pharmacotherapy 39 (2005): 2086-2090. -14. m. j. brown and coauthors, carotenoid bioavailability is higher from salads ingested with full-fat than with fat-reduced salad dressings as measured with electrochemical detection, american journal of clinical nutri- tion 80 (2004): 396-403. -15. p. lips, vitamin d physiology, progress in biophysics and molecular biology 92 (2006): 4-8. -16. h. f. deluca, overview of general physio- logic features and functions of vitamin d, american journal of clinical nutrition 80 (2004): 1689s-1696s. -17. p. t. liu and coauthors, toll-like receptor triggering of a vitamin d-mediated human antimicrobial response, science 311 (2006): 1770-1773; t. dietrich and coauthors, association between serum concentrations of 25-hydroxyvitamin d and gingival in- flammation, american journal of clinical nutrition 82 (2005): 575-580; j. welsh, vitamin d and breast cancer: insights from animal models, american journal of clinical nutrition 80 (2004): 1721s-1724s; i. a. van der mei and coauthors, past exposure to sun, skin phenotype, and risk of multiple sclerosis: case-control study, british medical journal 327 (2003): 316-321. -18. m. f. holick, vitamin d: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis, american journal of clinical nutrition 79 (2004): 362-371. -19. m. k. m. lehtonen-veromaa and coauthors, vitamin d and attainment of peak bone mass among peripubertal finnish girls: a 3-y prospective study, american journal of clinical nutrition 76 (2002): 1446-1453. -20. s. a. abrams, nutritional rickets: an old disease returns, nutrition reviews 60 (2002): 111-115. -21. p. weisberg and coauthors, nutritional rickets among children in the united states: review of cases reported between 1986 and 2003, american journal of clinical nutrition 80 (2004): 1697s-1705s. -22. m. f. holick, high prevalence of vitamin d inadequacy and implications for health, mayo clinic proceedings 81 (2006): 353-373. -23. m. s. calvo and s. j. whiting, prevalence of vitamin d insufficiency in canada and the united states: importance to health status and efficacy of current food fortification and dietary supplement use, nutrition re- views 61 (2003): 107-113. -24. h. a. bischoff-ferrari and coauthors, frac- ture prevention with vitamin d supplemen- tation: a meta-analysis of randomized controlled trials, journal of the american medical association 293 (2005): 2257-2264; h. a. bischoff-ferrari and coauthors, effect of vitamin d on falls: a meta-analysis, journal of the american medical association 291 (2004): 1999-2006. -25. h. a. bischoff-ferrari and coauthors, esti- mation of optimal serum concentrations of 25-hydroxyvitamin d for multiple health outcomes, american journal of clinical nutri- tion 84 (2006): 18-28. -26. m. s. calvo, s. l. whiting, and c. n. bar- ton, vitamin d fortification in the united states and canada: current status and data needs, american journal of clinical nutrition 80 (2004): 1710s-1716s; c. moore and coauthors, vitamin d intake in the united states, journal of the american dietetic associ- ation 104 (2004): 980-983. -27. m. f. holick, sunlight and vitamin d for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease, american journal of clinical nutrition 80 (2004): 1678s-1688s. -28. t. a. sentongo and coauthors, vitamin d status in children, adolescents, and young adults with crohn disease, american journal answers nutrition calculations 1. vitamin a: g rae vitamin d: g vitamin e: mg vitamin k: g 2. thiamin: legumes and grains riboflavin: milks, grains, and meats niacin: meats and grains vitamin b6: meats folate: legumes and vegetables vitamin b12: meats and milks vitamin c: vegetables and fruits the fat-soluble vitamins: a, d, e, and k 389 of clinical nutrition 76 (2002): 1077-1081; s. nesby-o dell and coauthors, hypovita- minosis d prevalence and determinants among african american and white women of reproductive age: third national health and nutrition examination survey, 1988- 1994, american journal of clinical nutrition 76 (2002): 187-192. -29. l. steingrimsdottir and coauthors, relation- ship between serum parathyroid hormone levels, vitamin d sufficiency, and calcium intake, journal of the american medical asso- ciation 294 (2005): 2336-2341. -30. r. p. heaney and coauthors, human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol, american journal of clinical nutrition 77 (2003): 204-210. -31. v. tangpricha and coauthors, tanning is associated with optimal vitamin d status (serum 25-hydroxyvitamin d concentra- tion) and higher bone mineral density, american journal of clinical nutrition 80 (2004): 1645-1649. -32. committee on dietary reference intakes, 2000. -33. s. devaraj and i. jialal, failure of vitamin e in clinical trials: is gamma-tocopherol the answer? -nutrition reviews 63 (2005): 290- 293; m. c. morris and coauthors, relation of the tocopherol forms to incident alzheimer disease and to cognitive change, american journal of clinical nutrition 81 (2005): 508-514; a. m. papas, beyond (cid:2)-tocopherol: the role of the other toco- pherols and tocotrienols, in m. s. meskin and coeditors, phytochemicals in nutrition and health (boca raton, fla.: crc press, 2002) pp. -61-77; q. jiang and coauthors, (cid:3)-tocopherol, the major form of vitamin e in the us diet, deserves more attention, american journal of clinical nutrition 74 (2001): 714-722. -34. u. singh, s. devaraj, and i. jialal, vitamin e, oxidative stress, and inflammation, annual review of nutrition 25 (2005): 151-174. -35. j. n. hathcock and coauthors, vitamins e and c are safe across a broad range of in- takes, american journal of clinical nutrition 81 (2005): 736-745. -36. r. s. bruno and coauthors, (cid:2)-tocopherol disappearance is faster in cigarette smokers and is inversely related to their ascorbic acid status, american journal of clinical nutrition 81 (2005): 95-103; j. maras and coauthors, intake of (cid:2)-tocopherol is limited among us adults, journal of the american dietetic associ- ation 104 (2004): 567-575. -37. committee on dietary reference intakes, 2000. -38. s. l. booth and coauthors, vitamin k intake and bone mineral density in women and men, american journal of clinical nutrition 77 (2003): 512-516. -39. k. d. cashman, vitamin k status may be an important determinant of childhood bone health, nutrition reviews 63 (2005): 284-293; h. j. kalkwarf and coauthors, vitamin k, bone turnover, and bone mass in girls, american journal of clinical nutrition 80 (2004): 1075-1080; n. c. binkley and coau- thors, a high phylloquinone intake is re- quired to achieve maximal osteocalcin (cid:3)-carboxylation, american journal of clinical nutrition 76 (2002): 1055-1060. -40. k. l. berkner, the vitamin k-dependent carboxylase, annual review of nutrition 25 (2005): 127-149. -41. m. a. johnson, influence of vitamin k on anticoagulant therapy depends on vitamin k status and the source and chemical forms of vitamin k, nutrition reviews 63 (2005): 91-100. vitamin a: vegetables, fruits, and milks vitamin d: milks vitamin e: legumes and oils taken together, the most groups form the usda food guide grains, vegetables, legumes, fruits, milks, meats, and oils. -study questions (multiple choice) 1. c 9. d 2. a 3. c 4. b 5. c 6. c 7. a 8. d 10. c highlight 11 antioxidant nutrients in disease prevention count on supplement manufacturers to ex- ploit the day s hot topics in nutrition. -the mo- ment bits of research news surface, new supplements appear and terms like antioxi- dants and lycopene become household words. -friendly faces in tv commercials try to persuade us that these supplements hold the magic in the fight against aging and disease. -new supplements hit the market and cash registers ring. -vitamin c, for years the leading single nutrient supplement, gains new popu- larity, and sales of lutein, beta-carotene, and vitamin e supplements soar as well. -in the meantime, scientists and medical ex- perts around the world continue their work to clarify and confirm the roles of antioxidants in preventing chronic dis- eases. -this highlight summarizes some of the accumulating evidence. -it also revisits the advantages of foods over supplements. -but first it is important to introduce the troublemakers the free radicals. -(the accompanying glossary defines free radicals and related terms.) -free radicals and disease chapter 7 described how the body s cells use oxygen in meta- bolic reactions. -in the process, oxygen sometimes reacts with body compounds and produces highly unstable molecules known as free radicals. -in addition to normal body processes, en- vironmental factors such as ultraviolet radiation, air pollution, and tobacco smoke generate free radicals. -a free radical is a molecule with one or more unpaired elec- trons. -* an electron without a partner is unstable and highly reac- tive. -to regain its stability, the free radical quickly finds a stable but vulnerable compound from which to steal an electron. -with the loss of an electron, the formerly stable molecule becomes a free radical itself and steals an electron from another nearby molecule. -thus, an electron-snatching chain reaction is under way with free radicals pro- ducing more free radicals. -antioxidants neu- tralize free radicals by donating one of their own electrons, thus ending the chain reac- tion. -when they lose electrons, antioxidants do not become free radicals because they are stable in either form. -(review figure 10-15 on p. 351 to see how ascorbic acid can give up two hydrogens with their electrons and become dehydroascorbic acid.) -s e g a m i y t t e g / i x a t / s t n e m e l c k c i n once formed, free radicals attack. -occa- sionally, these free-radical attacks are helpful. -for example, cells of the immune system use free radicals as ammunition in an oxida- tive burst that demolishes disease-causing viruses and bacteria. -most often, however, free-radical attacks cause widespread dam- age. -they commonly damage the polyunsaturated fatty acids in lipoproteins and in cell membranes, disrupting the transport of substances into and out of cells. -free radicals also alter dna, rna, and proteins, creating excesses and deficiencies of specific pro- teins, impairing cell functions, and eliciting an inflammatory re- sponse. -all of these actions contribute to cell damage, disease progression, and aging (see figure h11-1). -* many free radicals exist, but oxygen-derived free radicals are most common in the human body. -examples of oxygen-derived free radicals . -), hydroxyl radical (oh. -), and nitric oxide include superoxide radical (o2 (no.). -(the dots in the symbols represent the unpaired electrons.) -techni- cally, hydrogen peroxide (h2o2) and singlet oxygen are not free radicals because they contain paired electrons, but the unstable conformation of their electrons makes radical-producing reactions likely. -scientists some- times use the term reactive oxygen species (ros) to describe all of these compounds. -g lossary free radicals: unstable and highly reactive atoms or molecules that have one or more unpaired electrons in the outer orbital. -(see appendix b for a review of basic chemistry concepts.) -oxidants (oks-ih-dants): compounds (such as oxygen itself) that oxidize other compounds. -compounds that prevent oxidation are called antioxidants, whereas those that promote it are called prooxidants. -anti (cid:4) against pro (cid:4) for prooxidants: substances that significantly induce oxidative stress. -reminders: dietary antioxidants are substances typically found in foods that significantly decrease the adverse effects of free radicals on normal functions in the body. -nonnutrients are compounds in foods that do not fit into the six classes of nutrients. -phytochemicals are nonnutrient compounds found in plant- derived foods that have biological activity in the body. -oxidative stress is a condition in which the production of oxidants and free radicals exceeds the body s ability to handle them and prevent damage. -390 antioxidant nutrients in disease prevention 391 figure h11-1 free radical damage free radicals are highly reactive. -they might attack the polyunsaturated fatty acids in a cell membrane, which generates lipid radicals that damage cells and accelerate disease progression. -free radicals might also attack and damage dna, rna, and proteins, which inter- feres with the body s ability to maintain normal cell function, causing disease and premature aging. -free radical polyunsaturated fatty acids free radical free radical dna and rna proteins lipid radicals altered dna and rna altered proteins absence of specific proteins excess of specific proteins impaired cell function inflammatory response cell damage diseases aging the body s natural defenses and repair systems try to control the destruction caused by free radicals, but these systems are not 100 percent effective. -in fact, they become less effective with age, and the unrepaired damage accumulates. -to some extent, di- etary antioxidants defend the body against oxidative stress, but if antioxidants are unavailable or if free-radical production be- comes excessive, health problems may develop.1 oxygen-derived free radicals may cause diseases, not only by indiscriminately de- stroying the valuable components of cells, but also by serving as signals for specific activities within the cells. -scientists have iden- tified oxidative stress as a causative factor and antioxidants as a protective factor in cognitive performance and the aging process as well as in the development of diseases such as cancer, arthritis, cataracts, diabetes, and heart disease.2 defending against free radicals the body maintains a couple lines of defense against free-radical damage. -a system of enzymes disarms the most harmful oxi- dants. -* the action of these enzymes depends on the minerals se- lenium, copper, manganese, and zinc. -if the diet fails to provide adequate supplies of these minerals, this line of defense weakens. -the body also uses the antioxidant vitamins vitamin e, beta- * these enzymes include glutathione peroxidase, thioredoxin reductase, superoxide dismutase, and catalase. -carotene, and vitamin c. vitamin e defends the body s lipids (cell membranes and lipoproteins, for example) by efficiently stopping the free-radical chain reaction. -beta-carotene also acts as an an- tioxidant in lipid membranes. -vitamin c protects other tissues, such as the skin and fluid of the blood, against free-radical at- tacks.3 vitamin c seems especially adept at neutralizing free radi- cals from polluted air and cigarette smoke; it may also restore oxidized vitamin e to its active state. -dietary antioxidants may also include nonnutrients some of the phytochemicals (featured in highlight 13). -together, nu- trients and phytochemicals with antioxidant activity minimize damage in the following ways: limiting free-radical formation destroying free radicals or their precursors stimulating antioxidant enzyme activity repairing oxidative damage stimulating repair enzyme activity these actions play key roles in defending the body against cancer and heart disease. -defending against cancer cancers arise when cellular dna is damaged sometimes by free- radical attacks. -antioxidants may reduce cancer risks by protect- ing dna from this damage. -many researchers have reported low rates of cancer in people whose diets include abundant vegeta- bles and fruits, rich in antioxidants.4 preliminary reports suggest an inverse relationship between dna damage and vegetable 392 highlight 11 intake and a positive relationship with beef and pork intake. -labora- tory studies with animals and with cells in tissue culture also seem to support such findings. -foods rich in vitamin c seem to protect against certain types of cancers, especially those of the mouth, larynx, esophagus, and stomach. -such a correlation may reflect the benefits of a diet rich in fruits and vegetables and low in fat; it does not necessarily sup- port taking vitamin c supplements to treat or prevent cancer. -researchers hypothesize that vitamin e might inhibit cancer formation by attacking free radicals that damage dna. -evidence that vitamin e helps guard against cancer, however, is contradic- tory and inconclusive.5 several studies report a cancer-preventing benefit of vegeta- bles and fruits rich in beta-carotene and the other carotenoids as well. -carotenoids seem to protect against oxidative damage to dna.6 high concentrations of beta-carotene are associated with a lower mortality from all causes and lower rates of cancer.7 defending against heart disease high blood cholesterol carried in ldl is a major risk factor for car- diovascular disease, but how do ldl exert their damage? -one scenario is that free radicals within the arterial walls oxidize ldl, changing their structure and function. -the oxidized ldl then ac- celerate the formation of artery-clogging plaques.8 these free radicals also oxidize the polyunsaturated fatty acids of the cell membranes, sparking additional changes in the arterial walls, which impede the flow of blood. -susceptibility to such oxidative damage within the arterial walls is heightened by a diet high in saturated fat or cigarette smoke. -in contrast, diets that include plenty of fruits and vegetables, especially when combined with little saturated fat, strengthen antioxidant defenses against ldl oxidation. -antioxidant nutrients taken as supplements also seem to slow the early progression of atherosclerosis.9 antioxidants, especially vitamin e, may protect against cardio- vascular disease.10 epidemiological studies suggest that people who eat foods rich in vitamin e have relatively few atherosclerotic plaques and low rates of death from heart disease.11 similarly, large doses of vitamin e supplements may slow the progression of heart disease. -among its many protective roles, vitamin e defends against ldl oxidation, inflammation, arterial injuries, and blood clotting.12 less clear is whether vitamin e supplements benefit people who already have heart disease or multiple risk factors for it. -antioxidant supplements may not be beneficial and, in fact, may even be harmful for these people.13 vitamin c supplements may reduce the risk of heart disease.14 some studies suggest that vitamin c protects against ldl oxida- tion, raises hdl, lowers total cholesterol, and improves blood pressure. -vitamin c may also minimize inflammation and the free-radical action within the arterial wall.15 foods, supplements, or both? -in the process of scavenging and quenching free radicals, antiox- idants themselves become oxidized. -to some extent, they can be regenerated, but losses still occur and free radicals attack contin- uously. -to maintain defenses, a person must replenish dietary an- tioxidants regularly. -but should antioxidants be replenished from foods or from supplements? -foods especially fruits and vegetables offer not only antiox- idants, but an array of other valuable vitamins and minerals as well. -importantly, deficiencies of these nutrients can damage dna as readily as free radicals can. -eating fruits and vegetables in abundance protects against both deficiencies and diseases. -a ma- jor review of the evidence gathered from metabolic studies, epi- demiologic studies, and dietary intervention trials identified three dietary strategies most effective in preventing heart disease:16 use unsaturated fats (that have not been hydrogenated) instead of saturated or trans fats (see highlight 5). -select foods rich in omega-3 fatty acids (see chapter 5). -consume a diet high in fruits, vegetables, nuts, and whole grains and low in refined grain products. -such a diet combined with exercise, weight control, and not smoking serves as the best prescription for health. -notably, taking supplements is not among these disease-prevention rec- ommendations. -some research suggests a protective effect from as little as a daily glass of orange juice or carrot juice (rich sources of vitamin c and beta-carotene, respectively). -other intervention studies, however, have used levels of nutrients that far exceed current recommenda- tions and can be achieved only by taking supplements. -in making their recommendations for the antioxidant nutrients, members of the dri committee considered whether these studies support sub- stantially higher intakes to help protect against chronic diseases. -they did raise the recommendations for vitamins c and e, but they do not support taking vitamin pills over eating a healthy diet. -while awaiting additional research, should people anticipate the go-ahead and start taking antioxidant supplements now? -most scientists agree that the evidence is insufficient for such a recommendation.17 though fruits and vegetables containing many antioxidant nutrients and phytochemicals have been asso- ciated with a diminished risk of many cancers, supplements have not always proved beneficial. -in fact, sometimes the benefits are more apparent when the vitamins come from foods rather than from supplements. -in other words, the antioxidant actions of fruits and vegetables are greater than their nutrients alone can ex- plain.18 without data to confirm the benefits of supplements, we cannot accept the potential risks.19 and the risks are real. -consider the findings from meta-analysis studies of the rela- tionships between daily supplements of vitamin e, beta-carotene, or both and total mortality. -researchers concluded that supple- ments either had no benefit or increased mortality and should be avoided.20 even if research clearly proves that a particular nutrient is the ul- timate protective ingredient in foods, supplements would not be the answer because their contents are limited. -vitamin e supple- ments, for example, usually contain alpha-tocopherol, but foods provide an assortment of tocopherols among other nutrients, many of which provide valuable protection against free-radical damage. -in addition to a full array of nutrients, foods provide phy- tochemicals that also fight against many diseases.21 supplements shortchange users. -furthermore, supplements should only be used as an adjunct to other measures such as smoking cessation, weight control, physical activity, and medication as needed.22 clearly, much more research is needed to define optimal and dangerous levels of intake. -this much we know: antioxidants be- have differently under various conditions. -at physiological levels typical of a healthy diet, they act as antioxidants, but at pharma- cological doses typical of supplements, they may act as prooxi- dants, stimulating the production of free radicals and altering metabolism in a way that may promote disease. -a high intake of vitamin c from supplements, for example, may increase the risk of heart disease in women with diabetes.23 high doses (more than 400 iu per day) of vitamin e supplements may increase mortal- ity.24 until the optimum intake of antioxidant nutrients can be de- termined, the risks of supplement use remain unclear. -the best way to add antioxidants to the diet is to eat generous servings of fruits and vegetables daily. -it should be clear by now that we cannot know the identity and action of every chemical in every food. -even if we did, why create a supplement to replicate a food? -why not eat foods and antioxidant nutrients in disease prevention 393 t r a h n i e r n a y r b many cancer-fighting products are available now at your local pro- duce counter. -enjoy the pleasure, nourishment, and health benefits they pro- vide? -the beneficial constituents in foods are widespread among plants. -among the fruits, pomegranates, berries, and citrus rank high in antioxidants; top antioxidant vegetables include kale, spinach, and brussels sprouts; millet and oats contain the most antioxidants among the grains; pinto beans and soybeans are the outstanding legumes; and walnuts outshine the other nuts.25 but don t try to single out one particular food for its magic nutrient, antioxidant, or phytochemical. -instead, eat a wide variety of fruits, vegetables, grains, legumes, and nuts every day and get all the magic compounds these foods have to offer. -references 1. a. j. mceligot, s. yang, and f. l. meyskens, redox regulation by intrinsic species and extrinsic nutrients in normal and cancer cells, annual review of nutrition 25 (2005): 261-295; s. f. clark, the biochemistry of antioxidants revisited, nutrition in clinical practice 17 (2002): 5-17. -2. j. l. evans and coauthors, are oxidative stress-activated signaling pathways media- tors of insulin resistance and beta-cell dys- function? -diabetes 52 (2003): 1-8; f. grodstein, j. chen, and w. c. willett, high- dose antioxidant supplements and cognitive function in community-dwelling elderly women, american journal of clinical nutrition 77 (2003): 975-984; m. j. engelhart and coauthors, dietary intake of antioxidants and risk of alzheimer disease, journal of the american medical association 287 (2002): 3223-3229. -3. m. v. catani and coauthors, biological role of vitamin c in keratinocytes, nutrition reviews 63 (2005): 81-90. -4. d. p. hayes, the protective role of fruits and vegetables against radiation-induced cancer, nutrition reviews 63 (2005): 303-311; a. martin and coauthors, roles of vitamins e and c on neurodegenerative diseases and cognitive performance, nutrition reviews 60 (2002): 308-326; h. chen and coauthors, dietary patterns and adenocarcinoma of the esophagus and distal stomach, american journal of clinical nutrition 75 (2002): 137-144. -5. d. q. pham and r. plakogiannis, vitamin e supplementation in cardiovascular disease and cancer prevention: part 1, annals of pharmacotherapy 39 (2005): 1870-1878. -6. x. zhao and coauthors, modification of lymphocyte dna damage by carotenoid supplementation in postmenopausal women, american journal of clinical nutrition 83 (2006): 163-169. -7. b. buijsse and coauthors, plasma carotene and (cid:2)-tocopherol in relation to 10-y all- cause and cause-specific mortality in euro- pean elderly: the survey in europe on nutrition and the elderly, a concerted action (seneca), american journal of clini- cal nutrition 82 (2005): 879-886. -8. g. a. a. ferns and d. j. lamb, what does the lipoprotein oxidation phenomenon mean? -biochemical society transactions 32 (2004): 160-163; w. jessup, l. kritharides, and r. stocker, lipid oxidation in atheroge- nesis: an overview, biochemical society transactions 32 (2004): 134-138. -9. l. liu and m. meydani, combined vitamin c and e supplementation retards early progression of arteriosclerosis in heart transplant patients, nutrition reviews 60 (2002): 368-371; h. y. huang and coauthors, effects of vitamin c and vitamin e on in vivo lipid peroxidation: results of a ran- domized controlled trial, american journal of clinical nutrition 76 (2002): 549-555. -10. e. k. kabagambe and coauthors, some dietary and adipose tissue carotenoids are associated with the risk of nonfatal acute myocardial infarction in costa rica, journal of nutrition 135 (2005): 1763-1769; a. ian- nuzzi and coauthors, dietary and circulating antioxidant vitamins in relation to carotid plaques in middle-aged women, american journal of clinical nutrition 76 (2002): 582-587. -11. a. iannuzzi and coauthors, dietary and circulating antioxidant vitamins in relation to carotid plaques in middle-aged women, american journal of clinical nutrition 76 (2002): 582-587. -12. u. singh, s. devaraj, and i. jialal, vitamin e, oxidative stress, and inflammation, annual review of nutrition 25 (2005): 151-174; s. devaraj, a. harris, and i. jialal, modulation of monocyte-macrophage function with 394 highlight 11 (cid:2)-tocopherol: implications for atherosclero- sis, nutrition reviews 60 (2002): 8-14; l. j. van tits and coauthors, (cid:2)-tocopherol sup- plementation decreases production of superoxide and cytokines by leukocytes ex vivo in both normolipidemic and hyper- triglyceridemic individuals, american journal of clinical nutrition 71 (2000): 458-464; m. meydani, vitamin e and prevention of heart disease in high-risk patients, nutrition re- views 58 (2000): 278-281. -13. the hope and hope-too investigators, effects of long-term vitamin e supplementa- tion on cardiovascular events and cancer: a randomized controlled trial, journal of the american medical association 293 (2005): 1338-1347; d. d. waters and coauthors, effects of hormone replacement therapy and antioxidant vitamin supplements on coronary atherosclerosis in postmenopausal women: a randomized controlled trial, journal of the american medical association 288 (2002): 2432-2440. -14. p. knekt and coauthors, antioxidant vita- mins and coronary heart disease risk: a pooled analysis of 9 cohorts, american journal of clinical nutrition 80 (2004): 1508-1520. -15. s. g. wannamethee and coauthors, associa- tions of vitamin c status, fruit and vegetable intakes, and markers of inflammation and hemostasis, american journal of clinical nutrition 83 (2006): 567-574. -16. f. b. hu and w. c. willett, optimal diets for prevention of coronary heart disease, journal of the american medical association 288 (2002): 2569-2578. -17. h. y. huang and coauthors, the efficacy and safety of multivitamin and mineral supplement use to prevent cancer and chronic disease in adults: a systematic review for a national institutes of health state-of-the-science conference, annals of internal medicine 145 (2006): 372-385; p. m. kris-etherton and coauthors, antioxidant vitamin supplements and cardiovascular disease, circulation 110 (2004): 637-641. -18. l. o. dragsted and coauthors, the 6-a-day study: effects of fruit and vegetables on markers of oxidative stress and antioxidative defense in healthy nonsmokers, american journal of clinical nutrition 79 (2004): 1060-1072. -19. s. hercberg, the history of (cid:5)-carotene and cancers: from observational to intervention studies. -what lessons can be drawn for future research on polyphenols? -american journal of clinical nutrition 81 (2005): 218s- 222s. -20. e. r. miller and coauthors, meta-analysis: high-dosage vitamin e supplementation may increase all-cause mortality, annals of internal medicine 142 (2005): 37-46; i. lee and coauthors, vitamin e in the primary prevention of cardiovascular disease and cancer the women s health study: a randomized controlled trial, journal of the american medical association 294 (2005): 56- 65; d. p. vivekananthan and coauthors, use of antioxidant vitamins for the prevention of cardiovascular disease: meta-analysis of randomised trials, lancet 361 (2003): 2017-2023. -21. p. m. kris-etherton and coauthors, bioactive compounds in nutrition and health-research methodologies for establishing biological function: the antioxidant and anti-inflam- matory effects of flavonoids on atheroscle- rosis, annual review of nutrition 24 (2004): 511-538. -22. j. e. manson, s. s. bassuk, and m. j. stampfer, does vitamin e supplementation prevent cardiovascular events? -journal of womens health 12 (2003): 123-136. -23. d. h. lee and coauthors, does supplemen- tal vitamin c increase cardiovascular disease risk in women with diabetes? -american journal of clinical nutrition 80 (2004): 1194- 1200. -24. e. r. miller and coauthors, meta-analysis: high-dosage vitamin e supplementation may increase all-cause mortality, annals of internal medicine 142 (2005): 37-46. -25. b. l. halvorsen and coauthors, a systematic screening of total antioxidants in dietary plants, journal of nutrition 132 (2002): 461-471. this page intentionally left blank paul webster/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow figure 12-2: animated! -a nephron, one of the kidney s many functioning units figure 12-3: animated! -how the body regulates blood volume figure 12-12: animated! -calcium balance how to: practice problems nutrition portfolio journal nutrition in your life what s your beverage of choice? -if you said water, then congratulate yourself for recognizing its importance in maintaining your body s fluid balance. -if you answered milk, then pat yourself on the back for taking good care of your bones. -faced with a lack of water, you would realize within days how vital it is to your very survival. -the consequences of a lack of milk (or other calcium-rich foods) are also dramatic, but may not become apparent for decades. -water, calcium, and all the other major minerals support fluid balance and bone nutrition calculations: practice problems health. -before getting too comfortable reading this chapter, you might want to get yourself a glass of water or milk. -your body will thank you. -c h a p t e r 12 chapter outline water and the body fluids water balance and recommended intakes blood volume and blood pressure fluid and electrolyte balance fluid and elec- trolyte imbalance acid-base balance the minerals an overview sodium chloride potassium calcium calcium roles in the body calcium recommendation and sources calcium deficiency phosphorus magnesium sulfate highlight 12 osteoporosis and calcium water and the major minerals water is an essential nutrient, more important to life than any of the oth- ers. -the body needs more water each day than any other nutrient. -further- more, you can survive only a few days without water, whereas a deficiency of the other nutrients may take weeks, months, or even years to develop. -this chapter begins with a look at water and the body s fluids. -the body maintains an appropriate balance and distribution of fluids with the help of another class of nutrients the minerals. -in addition to introducing the minerals that help regulate body fluids, this chapter describes many of the other important functions minerals perform in the body. -chapter 19 revis- its water as a beverage and addresses consumer concerns about its safety. -water and the body fluids water constitutes about 60 percent of an adult s body weight and a higher percent- age of a child s (see figure 1 1, p. 6). -because water makes up about three-fourths of the weight of lean tissue and less than one-fourth of the weight of fat, a person s body composition influences how much of the body s weight is water. -the propor- tion of water is generally smaller in females, obese people, and the elderly because of their smaller proportion of lean tissue. -in the body, water is the fluid in which all life processes occur. -the water in the body fluids: carries nutrients and waste products throughout the body maintains the structure of large molecules such as proteins and glycogen participates in metabolic reactions serves as the solvent for minerals, vitamins, amino acids, glucose, and many other small molecules so that they can participate in metabolic activities acts as a lubricant and cushion around joints and inside the eyes, the spinal cord, and, in pregnancy, the amniotic sac surrounding the fetus in the womb aids in the regulation of normal body temperature (as chapter 14 explains, evaporation of sweat from the skin removes excess heat from the body.) -i s b r o c / e l o p l e a h c i m maintains blood volume water is the most indispensable nutrient. -397 398 chapter 12 water balance: intake = output to support these and other vital functions, the body actively maintains an appropri- ate water balance. -fluids in the body: intracellular (inside cells) extracellular (outside cells) interstitial (between cells) intravascular (inside blood vessels) reminder: the hypothalamus is a brain cen- ter that controls activities such as mainte- nance of water balance, regulation of body temperature, and control of appetite. -water balance: the balance between water intake and output (losses). -intracellular fluid: fluid within the cells, usually high in potassium and phosphate. -intracellular fluid accounts for approximately two-thirds of the body s water. -intra = within interstitial (in-ter-stish-al) fluid: fluid between the cells (intercellular), usually high in sodium and chloride. -interstitial fluid is a large component of extracellular fluid. -inter = in the midst, between extracellular fluid: fluid outside the cells. -extracellular fluid includes two main components the interstitial fluid and plasma. -extracellular fluid accounts for approximately one-third of the body s water. -extra = outside thirst: a conscious desire to drink. -dehydration: the condition in which body water output exceeds water input. -symptoms include thirst, dry skin and mucous membranes, rapid heartbeat, low blood pressure, and weakness. -water intoxication: the rare condition in which body water contents are too high in all body fluid compartments. -water balance and recommended intakes every cell contains fluid of the exact composition that is best for that cell (intracel- lular fluid) and is bathed externally in another such fluid (interstitial fluid). -in- terstitial fluid is the largest component of extracellular fluid. -figure 12-1 illustrates a cell and its associated fluids. -these fluids continually lose and replace their components, yet the composition in each compartment remains remarkably constant under normal conditions. -because imbalances can be devastating, the body quickly responds by adjusting both water intake and excretion as needed. -con- sequently, the entire system of cells and fluids remains in a delicate, but controlled, state of homeostasis. -water intake thirst and satiety influence water intake, apparently in response to changes sensed by the mouth, hypothalamus, and nerves. -when water intake is inadequate, the blood becomes concentrated (having lost water but not the dis- solved substances within it), the mouth becomes dry, and the hypothalamus initi- ates drinking behavior. -when water intake is excessive, the stomach expands and stretch receptors send signals to stop drinking. -similar signals are sent from recep- tors in the heart as blood volume increases. -thirst drives a person to seek water, but it lags behind the body s need. -when too much water is lost from the body and not replaced, dehydration develops. -a first sign of dehydration is thirst, the signal that the body has already lost some of its fluid. -if a person is unable to obtain fluid or, as in many elderly people, fails to per- ceive the thirst message, the symptoms of dehydration may progress rapidly from thirst to weakness, exhaustion, and delirium and end in death if not corrected (see table 12-1). -dehydration may easily develop with either water deprivation or exces- sive water losses. -(chapter 14 revisits dehydration and the fluid needs of athletes.) -water intoxication, on the other hand, is rare but can occur with excessive water ingestion and kidney disorders that reduce urine production. -the symptoms may include confusion, convulsions, and even death in extreme cases. -excessive water ingestion (10 to 20 liters) within a few hours contributes to the dangerous condition known as hyponatremia, sometimes seen in endurance athletes. -for this reason, guidelines suggest limiting fluid intake during times of heavy sweating to 1 to 1.5 liters per hour.1 (chapter 14 revisits hyponatremia.) -water sources the obvious dietary sources of water are water itself and other beverages, but nearly all foods also contain water. -most fruits and vegetables con- tain up to 90 percent water, and many meats and cheeses contain at least 50 per- cent. -(see table 12-2 for selected foods and appendix h for many more.) -also, water is generated during metabolism. -recall from chapter 7 that when the energy-yielding table 12-1 signs of dehydration body weight lost (%) symptoms 1 2 3 4 5 6 thirst, fatigue, weakness, vague discomfort, loss of appetite impaired physical performance, dry mouth, reduction in urine, flushed skin, impatience, apathy difficulty concentrating, headache, irritability, sleepiness, impaired tem- perature regulation, increased respiratory rate 7 10 dizziness, spastic muscles, loss of balance, delirium, exhaustion, collapse note: the onset and severity of symptoms at various percentages of body weight lost depend on the activity, fitness level, degree of acclimation, temperature, and humidity. -if not corrected, dehydration can lead to death. -table 12-2 percentage of water in selected foods 100% water 90 99% fat-free milk, strawberries, watermelon, lettuce, cabbage, celery, spinach, broccoli 80 89% fruit juice, yogurt, apples, grapes, oranges, carrots 70 79% shrimp, bananas, corn, potatoes, avocados, cottage cheese, ricotta cheese 60 69% pasta, legumes, salmon, ice cream, chicken breast 50 59% ground beef, hot dogs, feta cheese 40 49% pizza 30 39% cheddar cheese, bagels, bread 20 29% pepperoni sausage, cake, biscuits 10 19% butter, margarine, raisins 1 9% 0% crackers, cereals, pretzels, taco shells, peanut butter, nuts oils, sugars nutrients break down, their carbons and hydrogens combine with oxygen to yield carbon dioxide (co2) and water (h2o). -as table 12-3 shows, the water derived daily from these three sources averages about 21/2 liters (roughly 21/2 quarts or 101/2 cups). -water losses the body must excrete a minimum of about 500 milliliters (about 2 cups) of water each day as urine enough to carry away the waste products gener- ated by a day s metabolic activities. -above this amount, excretion adjusts to balance intake. -if a person drinks more water, the kidneys excrete more urine, and the urine becomes more dilute. -in addition to urine, water is lost from the lungs as vapor and from the skin as sweat; some is also lost in feces. -* the amount of fluid lost from each source varies, depending on the environment (such as heat or humidity) and physi- cal conditions (such as exercise or fever). -on average, daily losses total about 21/2 liters. -table 12-3 shows how water excretion balances intake; maintaining this bal- ance requires healthy kidneys and an adequate intake of fluids. -water recommendations because water needs vary depending on diet, activity, environmental temperature, and humidity, a general water requirement is difficult to establish. -recommendations are sometimes expressed in proportion to the amount of energy expended under average environmental conditions.2 the recommended water intake for a person who expends 2000 kcalories a day, for example, is 2 to 3 liters of water (about 8 to 12 cups). -this recommendation is in line with the adequate intake (ai) for total water set by the dri committee. -total water includes not only drinking water, but water in other beverages and in foods as well. -table 12-3 water balance water sources amount (ml) water losses amount (ml) liquids foods 550 to 1500 700 to 1000 metabolic water 200 to 300 kidneys (urine) skin (sweat) lungs (breath) gi tract (feces) 500 to 1400 450 to 900 350 150 total 1450 to 2800 total 1450 to 2800 note: for perspective, 100 ml is a little less than 1/2 cup and 1000 ml is a little more than 1 quart (1 ml = 0.03 oz). -* water lost from the lungs and skin accounts for almost one-half of the daily losses even when a per- son is not visibly perspiring; these losses are commonly referred to as insensible water losses. -** for those using kilojoules: 4.2 to 6.3 ml/kj expended. -water and the major minerals 399 figure 12-1 one cell and its associated fluids fluids are found within the cells (intra- cellular) or outside the cells (extracellu- lar). -extracellular fluids include plasma (the fluid portion of blood in the intravascular spaces of blood vessels) and interstitial fluids (the tissue fluid that fills the intercellular spaces between the cells). -fluid between the cells (intercellular or interstitial) cell membrane nucleus fluid within the cell (intracellular) fluid (plasma) within the blood vessels (intravascular) blood vessel the amount of water the body has to excrete each day to dispose of its wastes is the obligatory (ah-blig-ah-tore-ee) water excretion about 500 ml (about 2 c, or a pint). -water recommendation: 1.0 to 1.5 ml/kcal expended (adults)** 1.5 ml/kcal expended (infants and athletes) conversion factors: 1 ml = 0.03 fluid ounce 125 ml (cid:2) 1/2 c easy estimation: 1/2 c per 100 kcal expended ai for total water: men: 3.7 l/day women: 2.7 l/day conversion factors: 1 l (cid:2) 1 qt (cid:2) 32 oz (cid:2) 4 c 400 chapter 12 because a wide range of water intakes will prevent dehydration and its harmful consequences, the ai is based on average intakes. -people who are physically active or who live in hot environments may need more.3 which beverages are best? -any beverage can readily meet the body s fluid needs, but those with few or no kcalories do so without contributing to weight gain. -given that obesity is a major health problem and that beverages currently represent over 20 percent of the total energy intake in the united states, most people would do well to select water as their preferred beverage. -other choices include tea, coffee, nonfat and low-fat milk and soymilk, artificially sweetened beverages, fruit and vegetable juices, sports drinks, and lastly, sweetened nutri- ent-poor beverages.4 some research indicates that people who drink caffeinated beverages lose a lit- tle more fluid than when drinking water because caffeine acts as a diuretic. -the dri committee considered such findings in their recommendations for water in- take and concluded: caffeinated beverages contribute to the daily total water in- take similar to that contributed by non-caffeinated beverages. -5 in other words, it doesn t seem to matter whether people rely on caffeine-containing beverages or other beverages to meet their fluid needs. -as highlight 7 explained, alcohol acts as a diuretic, and it has many adverse effects on health and nutrition status. -alcohol should not be used to meet fluid needs. -health effects of water in addition to meeting the body s fluid needs, drinking plenty of water may protect against urinary stones and constipation.6 even mild de- hydration seems to interfere with daily tasks involving concentration, alertness, and short-term memory.7 the kind of water a person drinks may also make a difference to health. -water is usually either hard or soft. -hard water has high concentrations of calcium and magnesium; sodium or potassium is the principal mineral of soft water. -(see the accompanying glossary for these and other common terms used to describe water.) -in practical terms, soft water makes more bubbles with less soap; hard water leaves a ring on the tub, a crust of rocklike crystals in the teakettle, and a gray residue in the laundry. -soft water may seem more desirable around the house, and some homeowners purchase water softeners that replace magnesium and calcium with sodium. -in the body, however, soft water with sodium may aggravate hypertension and heart dis- ease. -in contrast, the minerals in hard water may benefit these conditions. -g lossary of water terms artesian water: water drawn filtered water: water treated by from a well that taps a confined aquifer in which the water is under pressure. -bottled water: drinking water sold in bottles. -carbonated water: water that contains carbon dioxide gas, either naturally occurring or added, that causes bubbles to form in it; also called bubbling or sparkling water. -seltzer, soda, and tonic waters are legally soft drinks and are not regulated as water. -distilled water: water that has been vaporized and recon- densed, leaving it free of dis- solved minerals. -filtration, usually through activated carbon filters that reduce the lead in tap water, or by reverse osmosis units that force pressurized water across a membrane removing lead, arsenic, and some microorganisms from tap water. -hard water: water with a high calcium and magnesium content. -mineral water: water from a spring or well that typically contains 250 to 500 parts per million (ppm) of minerals. -minerals give water a distinctive flavor. -many mineral waters are high in sodium. -natural water: water obtained from a spring or well that is certified to be safe and sanitary. -the mineral content may not be changed, but the water may be treated in other ways such as with ozone or by filtration. -public water: water from a municipal or county water system that has been treated and disinfected. -purified water: water that has been treated by distillation or other physical or chemical processes that remove dissolved solids. -because purified water contains no minerals or contaminants, it is useful for medical and research purposes. -soft water: water with a high sodium or potassium content. -spring water: water originating from an underground spring or well. -it may be bubbly (carbon- ated), or flat or still, mean- ing not carbonated. -brand names such as spring pure do not necessarily mean that the water comes from a spring. -well water: water drawn from ground water by tapping into an aquifer. -water and the major minerals 401 soft water also more easily dissolves certain contaminant minerals, such as cad- mium and lead, from old plumbing pipes. -as chapter 13 explains, these contami- nant minerals harm the body by displacing the nutrient minerals from their normal sites of action. -people who live in old buildings should run the cold water tap a minute to flush out harmful minerals whenever the water faucet has been off for more than six hours. -many people select bottled water, believing it to be safer than tap water and therefore worth its substantial cost. -chapter 19 offers a discussion of bottled water safety and regulations. -in summary water makes up about 60 percent of the adult body s weight. -it assists with the transport of nutrients and waste products throughout the body, participates in chemical reactions, acts as a solvent, serves as a shock absorber, and regulates body temperature. -to maintain water balance, intake from liquids, foods, and metabolism must equal losses from the kidneys, skin, lungs, and gi tract. -the amount and type of water a person drinks may have positive or negative health effects. -blood volume and blood pressure fluids maintain the blood volume, which in turn influences blood pressure. -the kid- neys are central to the regulation of blood volume and blood pressure.8 all day, every day, the kidneys reabsorb needed substances and water and excrete wastes with some water in the urine (see figure 12-2 on p. 402). -the kidneys meticulously adjust the volume and the concentration of the urine to accommodate changes in the body, including variations in the day s food and beverage intakes. -instructions on whether to retain or release substances or water come from adh, renin, an- giotensin, and aldosterone. -adh and water retention whenever blood volume or blood pressure falls too low, or whenever the extracellular fluid becomes too concentrated, the hypothala- mus signals the pituitary gland to release antidiuretic hormone (adh). -adh is a water-conserving hormone that stimulates the kidneys to reabsorb water. -conse- quently, the more water you need, the less your kidneys excrete. -these events also trigger thirst. -drinking water and retaining fluids raise the blood volume and dilute the concentrated fluids, thus helping to restore homeostasis. -renin and sodium retention cells in the kidneys respond to low blood pressure by releasing an enzyme called renin. -through a complex series of events, renin causes the kidneys to reabsorb sodium. -sodium reabsorption, in turn, is always accompa- nied by water retention, which helps to restore blood volume and blood pressure. -angiotensin and blood vessel constriction in addition to its role in sodium retention, renin converts the blood protein angiotensinogen to its active form angiotensin. -angiotensin is a powerful vasoconstrictor that narrows the diam- eters of blood vessels, thereby raising the blood pressure. -aldosterone and sodium retention in addition to acting as a vasoconstrictor, angiotensin stimulates the release of the hormone aldosterone from the adrenal glands. -aldosterone signals the kidneys to retain more sodium, and therefore water, because when sodium moves, fluids follow. -again, the effect is that when more water is needed, less is excreted. -all of these actions are presented in figure 12-3 (p. 403) and help to explain why high-sodium diets aggravate conditions such as hypertension or edema. -too much reminder: antidiuretic hormone (adh) is a hormone produced by the pituitary gland in response to dehydration (or a high sodium concentration in the blood). -it stim- ulates the kidneys to reabsorb more water and therefore to excrete less. -recall from highlight 7 that alcohol depresses adh activity, thus promoting fluid losses and dehydration. -in addition to its antidiuretic effect, adh elevates blood pressure and so is also called vasopressin (vas-oh-pres-in). -vaso = vessel press = pressure renin (ren-in): an enzyme from the kidneys that activates angiotensin. -angiotensin (an-gee-oh-ten-sin): a hormone involved in blood pressure regulation. -its precursor protein is called angiotensinogen; it is activated by renin, an enzyme from the kidneys. -vasoconstrictor (vas-oh-kon-strik-tor): a substance that constricts or narrows the blood vessels. -aldosterone (al-dos-ter-own): a hormone secreted by the adrenal glands that regulates blood pressure by increasing the reabsorption of sodium by the kidneys. -aldosterone also regulates chloride and potassium concentrations. -adrenal glands: glands adjacent to, and just above, each kidney. -402 chapter 12 figure 12-2 animated! -a nephron, one of the kidney s many functioning units to test your understanding of these concepts, log on to www.thomsonedu.com/login a nephron (a working unit of the kidney). -each kidney contains over one million nephrons. -blood vessel glomerulus capillaries of glomerulus kidney ureter pelvis bladder to the body renal artery renal vein 1 2 1 blood flows into the glomerulus, and some of its fluid, with dissolved substances, is absorbed into the tubule. -tubule 2 then the fluid and substances needed by the body are returned to the blood in vessels alongside the tubule. -3 3 the tubule passes waste materials on to the bladder. -to the bladder kidney, sectioned to show location of nephrons the cleansing of blood in the nephron is roughly analogous to the way you might clean your car. -first you remove all your possessions and trash so that the car can be vacuumed. -then you put back in the car what you want to keep and throw away the trash. -2 1 3 sodium causes water retention and an accompanying rise in blood pressure or swelling in the interstitial spaces. -chapter 18 discusses hypertension in detail. -in summary in response to low blood volume, low blood pressure, or highly concentrated body fluids, these actions combine to effectively restore homeostasis: adh retains water. -renin retains sodium. -angiotensin constricts blood vessels. -aldosterone retains sodium. -these actions can maintain water balance only if a person drinks enough water. -fluid and electrolyte balance maintaining a balance of about two-thirds of the body fluids inside the cells and one- third outside is vital to the life of the cells. -if too much water were to enter the cells, they might rupture; if too much water were to leave, they would collapse. -to control the movement of water, the cells direct the movement of the major minerals. -the major minerals: sodium chloride potassium calcium phosphorus magnesium sulfur figure 12-3 animated! -how the body regulates blood volume to test your understanding of these concepts, log on to www.thomsonedu.com/login kidneys brain the kidneys respond to reduced blood flow by releasing the enzyme renin. -renin the hypothalamus responds to high salt concentrations in the blood by stimulating the pituitary gland. -renin initiates the activation of the protein angiotensinogen to angiotensin. -the pituitary gland releases antidiuretic hormone (adh). -angiotensin angiotensin signals the adrenal glands to secrete aldosterone. -aldosterone angiotensin causes the blood vessels to constrict, raising pressure. -adh aldosterone and adh signal the kidneys to retain sodium and water, respectively, thus increasing blood volume. -dissociation of salt in water when a mineral salt such as sodium chloride (nacl) dissolves in water, it separates (dissociates) into ions positively and neg- atively charged particles (na+ and cl ). -the positive ions are cations; the negative ones are anions. -unlike pure water, which conducts electricity poorly, ions dis- solved in water carry electrical current. -for this reason, salts that dissociate into ions are called electrolytes, and fluids that contain them are electrolyte solutions. -in all electrolyte solutions, anion and cation concentrations are balanced (the number of negative and positive charges are equal). -if a fluid contains 1000 nega- tive charges, it must contain 1000 positive charges, too. -if an anion enters the fluid, a cation must accompany it or another anion must leave so that electrical neutral- ity will be maintained. -thus, whenever sodium (na+) ions leave a cell, potassium (k+) ions enter, for example. -in fact, it s a good bet that whenever na+ and k+ ions are moving, they are going in opposite directions. -table 12-4 (p. 404) shows that, indeed, the positive and negative charges inside and outside cells are perfectly balanced even though the numbers of each kind of ion differ over a wide range. -inside the cells, the positive charges total 202 and the negative charges balance these perfectly. -outside the cells, the amounts and pro- portions of the ions differ from those inside, but again the positive and negative charges balance. -(scientists count these charges in milliequivalents, meq.) -electrolytes attract water electrolytes attract water. -each water molecule has a net charge of zero, but the oxygen side of the molecule has a slight negative charge, and the hydrogens have a slight positive charge. -figure 12-4 (p. 404) shows the result in an electrolyte solution: both positive and negative ions attract clusters of water water and the major minerals 403 to remember the difference between cations and anions, think of the t in cations as a plus (+) sign and the n in anions as negative. -a neutral molecule, such as water, that has opposite charges spatially separated within the molecule is polar. -see appendix b for more details. -salt: a compound composed of a positive ion other than h+ and a negative ion other than oh-. -an example is sodium chloride (na+ cl-). -na = sodium cl = chloride dissociates (dis-so-see-aites): physically separates. -ions (eye-uns): atoms or molecules that have gained or lost electrons and therefore have electrical charges. -examples include the positively charged sodium ion (na+) and the negatively charged chloride ion (cl-). -for a closer look at ions, see appendix b. cations (cat-eye-uns): positively charged ions. -anions (an-eye-uns): negatively charged ions. -electrolytes: salts that dissolve in water and dissociate into charged particles called ions. -electrolyte solutions: solutions that can conduct electricity. -milliequivalents (meq): the concentration of electrolytes in a volume of solution. -milliequivalents are a useful measure when considering ions because the number of charges reveals characteristics about the solution that are not evident when the concentration is expressed in terms of weight. -404 chapter 12 table 12-4 important body electrolytes electrolytes cations (positively charged ions) sodium (na(cid:2)) potassium (k(cid:2)) calcium (ca(cid:2)(cid:2)) magnesium (mg(cid:2)(cid:2)) anions (negatively charged ions) chloride (cl(cid:3)) (cid:3)) bicarbonate (hco3 (cid:4)) phosphate (hpo4 sulfate (so4 organic acids (lactate, pyruvate) (cid:4)) proteins intracellular (inside cells) concentration (meq/l) extracellular (outside cells) concentration (meq/l) 10 150 2 40 202 2 10 103 20 10 57 202 142 5 5 3 155 103 27 2 1 6 16 155 the word ending -ate denotes a salt of the mineral. -thus, phosphate is the salt form of the mineral phosphorus, and sulfate is the salt form of sulfur. -note: the numbers of positive and negative charges in a given fluid are the same. -for example, in extracellular fluid, the cations and anions both equal 155 milliequivalents per liter (meq/l). -of the cations, sodium ions make up 142 meq/l; and potassium, calcium, and magnesium ions make up the remainder. -of the anions, chloride ions number 103 meq/l; bicarbonate ions number 27; and the rest are provided by phosphate ions, sulfate ions, organic acids, and protein. -molecules around them. -this attraction dissolves salts in water and enables the body to move fluids into appropriate compartments. -water follows electrolytes as figure 12-5 shows, some electrolytes reside pri- marily outside the cells (notably, sodium and chloride), whereas others reside pre- dominantly inside the cells (notably, potassium, magnesium, phosphate, and sulfate). -cell membranes are selectively permeable, meaning that they allow the pas- figure 12-4 water dissolves salts and follows electrolytes the structural arrangement of the two hydrogen atoms and one oxygen atom enables water to dissolve salts. -water s role as a solvent is one of its most valuable characteristics. -+ h ho + the negatively charged electrons that bond the hydrogens to the oxygen spend most of their time near the oxygen atom. -as a result, the oxygen is slightly negative, and the hydrogens are slightly positive (see appendix b). -cl na+ na+ cl in an electrolyte solution, water molecules are attracted to both anions and cations. -notice that the negative oxygen atoms of the water molecules are drawn to the sodium cation (na+), whereas the positive hydrogen atoms of the water molecules are drawn to the chloride ions (cl ). -figure 12-5 a cell and its electrolytes all of these electrolytes are found both inside and outside the cells, but each can be found mostly on one side or the other of the cell membrane. -water and the major minerals 405 e r o o m . -m g i a r c e r o o m . -m g i a r c when immersed in water, raisins become plump because water moves toward the higher concentration of sugar inside the raisins. -when sprinkled with salt, vegetables sweat because water moves toward the higher con- centration of salt outside the eggplant. -chemical symbols: (cid:129)k = potassium (cid:129)p = phosphorus (cid:129)mg = magnesium (cid:129)s = sulfate (cid:129)na = sodium (cid:129)cl = chloride outside the cells cell membrane k p mg s within the cell na cl key: cations anions blood vessel sage of some molecules, but not others. -whenever electrolytes move across the membrane, water follows. -the movement of water across a membrane toward the more concentrated solutes is called osmosis. -the amount of pressure needed to prevent the move- ment of water across a membrane is called the osmotic pressure. -figure 12-6 presents osmosis, and the photos of salted eggplant and rehydrated raisins provide familiar examples. -proteins regulate flow of fluids and ions chapter 6 described how proteins attract water and help to regulate fluid movement. -in addition, transport proteins in figure 12-6 osmosis water flows in the direction of the more highly concentrated solution. -a b a b a b 2 now additional solute is added to side b. solute cannot flow across the divider (in the case of a cell, its membrane). -1 with equal numbers of solute particles on both sides of the semipermeable membrane, the concentrations are equal, and the tendency of water to move in either direction is about the same. -3 water can flow both ways across the divider, but has a greater tendency to move from side a to side b, where there is a greater concentration of solute. -the volume of water becomes greater on side b, and the concentrations on side a and b become equal. -solutes (soll-yutes): the substances that are dissolved in a solution. -the number of molecules in a given volume of fluid is the solute concentration. -osmosis: the movement of water across a membrane toward the side where the solutes are more concentrated. -osmotic pressure: the amount of pressure needed to prevent the movement of water across a membrane. -406 chapter 12 physically active people must remember to replace their body fluids. -health care workers use oral rehydration therapy (ort) a simple solution of sugar, salt, and water, taken by mouth to treat dehydration caused by diarrhea. -a simple ort recipe (cool before giving): 1/2 l boiling water a small handful of sugar (4 tsp) 3 pinches of salt (1/2 tsp) reminder: ph is the unit of measure expressing a substance s acidity or alkalinity. -the cell membranes regulate the passage of positive ions and other substances from one side of the membrane to the other. -negative ions follow positive ions, and wa- ter flows toward the more concentrated solution. -a protein that regulates the flow of fluids and ions in and out of cells is the sodium-potassium pump. -the pump actively exchanges sodium for potassium across the cell membrane, using atp as an energy source. -figure 6-10 on p. 192 il- lustrates this action. -regulation of fluid and electrolyte balance the amounts of various miner- als in the body must remain nearly constant. -regulation occurs chiefly at two sites: the gi tract and the kidneys. -the digestive juices of the gi tract contain minerals. -these minerals and those from foods are reabsorbed in the large intestine as needed. -each day, 8 liters of flu- ids and associated minerals are recycled this way, providing ample opportunity for the regulation of electrolyte balance. -i s b r o c / r e f e a h c s t r e b r o n the kidneys control of the body s water content by way of the hormone adh has already been described (see p. 401). -to regulate the electrolyte contents, the kidneys depend on the adrenal glands, which send out messages by way of the hormone al- dosterone (also explained on p. 401). -if the body s sodium is low, aldosterone stim- ulates sodium reabsorption from the kidneys. -as sodium is reabsorbed, potassium (another positive ion) is excreted in accordance with the rule that total positive charges must remain in balance with total negative charges. -fluid and electrolyte imbalance normally, the body defends itself successfully against fluid and electrolyte imbal- ances. -certain situations and some medications, however, may overwhelm the body s ability to compensate. -severe, prolonged vomiting and diarrhea as well as heavy sweating, burns, and traumatic wounds may incur such great fluid and electrolyte losses as to precipitate a medical emergency. -different solutes lost by different routes different solutes are lost depending on why fluid is lost. -if fluid is lost by vomiting or diarrhea, sodium is lost indis- criminately. -if the adrenal glands oversecrete aldosterone, as may occur when they develop a tumor, the kidneys may excrete too much potassium. -also, the per- son with uncontrolled diabetes may lose glucose, a solute not normally excreted, and large amounts of fluid with it. -each situation results in dehydration, but drinking water alone cannot restore electrolyte balance. -medical intervention is required. -replacing lost fluids and electrolytes in many cases, people can replace the fluids and minerals lost in sweat or in a temporary bout of diarrhea by drinking plain cool water and eating regular foods. -some cases, however, demand rapid re- placement of fluids and electrolytes for example, when diarrhea threatens the life of a malnourished child. -caregivers around the world have learned to use simple formulas to treat mild-to-moderate cases of diarrhea. -these lifesaving formulas do not require hospitalization and can be prepared from ingredients available locally. -caregivers need only learn to measure ingredients carefully and use sanitary water. -once rehydrated, a person can begin eating foods. -(chapter 14 presents a discussion of sport drinks.) -acid-base balance the body uses its ions not only to help maintain fluid and electrolyte balance, but also to regulate the acidity (ph) of its fluids. -the ph scale introduced in chapter 3 is repeated here, in figure 12-7, with the normal and abnormal ph ranges of the blood added. -as you can see, the body must maintain the ph within a narrow range to avoid life-threatening consequences. -slight deviations in either direction can de- water and the major minerals 407 figure 12-7 the ph scale ph of common substances basic 14 concentrated lye normal and abnormal ph ranges of blood 8.00 death 13 12 11 10 9 8 7 6 5 4 3 2 1 0 ph neutral acidic household ammonia alkalosis baking soda pancreatic juice blood water milk urine coffee orange juice vinegar lemon juice gastric juice battery acid 7.45 7.35 normal acidosis 6.8 death note: each step is ten times as concentrated in base (1 10 as much acid, or h(cid:2)) as the one below it. -nature proteins, causing metabolic mayhem. -enzymes couldn t catalyze reactions and hemoglobin couldn t carry oxygen to name just two examples. -the acidity of the body s fluids is determined by the concentration of hydrogen ions (h+). -a high concentration of hydrogen ions is very acidic. -normal energy metabolism generates hydrogen ions, as well as many other acids, that must be neutralized. -three systems defend the body against fluctuations in ph buffers in the blood, respiration in the lungs, and excretion in the kidneys. -regulation by the buffers bicarbonate (a base) and carbonic acid (an acid) in the body fluids (as well as some proteins) protect the body against changes in acidity by acting as buffers substances that can neutralize acids or bases. -figure 12-8 (p. 408) presents the chemical reactions of this buffer system, which is prima- rily under the control of the lungs and kidneys. -carbon dioxide, which is formed all the time during energy metabolism, dis- solves in water to form carbonic acid in the blood. -carbonic acid, in turn, dissociates to form hydrogen ions and bicarbonate ions. -the appropriate balance between car- bonic acid and bicarbonate is essential to maintaining optimal blood ph. -regulation in the lungs the lungs control the concentration of carbonic acid by raising or slowing the respiration rate, depending on whether the ph needs to be in- creased or decreased. -if too much carbonic acid builds up, the respiration rate speeds up; this hyperventilation increases the amount of carbon dioxide exhaled, thereby lowering the carbonic acid concentration and restoring homeostasis. -conversely, if bicarbonate builds up, the respiration rate slows; carbon dioxide is retained and forms more carbonic acid. -again, homeostasis is restored. -the lower the ph, the higher the h+ ion concentration and the stronger the acid. -a ph above 7 is alkaline, or base (a solution in which oh ions predominate). -reminder: bicarbonate is an alkaline com- pound with the formula hco3. -it is pro- duced in all cell fluids from the dissociation of carbonic acid to help maintain the body s acid-base balance. -(bicarbonate is also secreted from the pancreas during digestion as part of the pancreatic juice.) -carbonic acid: a compound with the formula h2co3 that results from the combination of carbon dioxide (co2) and water (h2o); of particular importance in maintaining the body s acid-base balance. -408 chapter 12 reminder: an inorganic substance does not contain carbon. -major minerals: essential mineral nutrients found in the human body in amounts larger than 5 g; sometimes called macrominerals. -figure 12-8 bicarbonate-carbonic acid buffer system the reversible reactions of the bicarbonate-carbonic acid buffer system help to reg- ulate the body s ph. -recall from chapter 7 that carbon dioxide and water are formed during energy metabolism. -carbon dioxide (co2) is a volatile gas that quickly dissolves in water (h2o), forming carbonic acid (h2co3): co2 carbon dioxide + + h2o water h2co3 carbonic acid carbonic acid readily dissociates to a hydrogen ion (h+) and a bicarbonate ion (hco3): h2co3 h+ carbonic acid hydrogen ion + + hco3 bicarbonate ion regulation in the kidneys the kidneys control the concentration of bicarbonate by either reabsorbing or excreting it, depending on whether the ph needs to be in- creased or decreased, respectively. -their work is complex, but the net effect is easy to sum up. -the body s total acid burden remains nearly constant; the acidity of the urine fluctuates to accommodate that balance. -in summary electrolytes (charged minerals) in the fluids help distribute the fluids inside and outside the cells, thus ensuring the appropriate water balance and acid- base balance to support all life processes. -excessive losses of fluids and elec- trolytes upset these balances, and the kidneys play a key role in restoring homeostasis. -the minerals an overview figure 12-9 (p. 409) shows the amounts of the major minerals found in the body and, for comparison, some of the trace minerals. -the distinction between the major and trace minerals does not mean that one group is more important than the other all minerals are vital. -the major minerals are so named because they are present, and needed, in larger amounts in the body. -they are shown at the top of the figure and are discussed in this chapter. -the trace minerals (shown at the bottom) are discussed in chapter 13. a few generalizations pertain to all of the minerals and distinguish them from the vitamins. -especially notable is their chemical nature. -inorganic elements unlike the organic vitamins, which are easily destroyed, minerals are inorganic elements that always retain their chemical identity. -once minerals enter the body proper, they remain there until excreted; they can- not be changed into anything else. -iron, for example, may temporarily combine with other charged elements in salts, but it is always iron. -neither can minerals be destroyed by heat, air, acid, or mixing. -consequently, little care is needed to pre- serve minerals during food preparation. -in fact, the ash that remains when a food is burned contains all the minerals that were in the food originally. -minerals can be lost from food only when they leach into cooking water that is then poured down the drain. -figure 12-9 minerals in a 60-kilogram (132-pound) human body not only are the major minerals present in the body in larger amounts than the trace minerals, but they are also needed by the body in larger amounts. -recommended intakes for the major minerals are stated in hundreds of milligrams or grams, whereas those for the trace minerals are listed in tens of milligrams or even micrograms. -calcium phosphorus potassium sulfur sodium chloride magnesium 30 iron zinc copper manganese iodine selenium 2.4 2.0 0.09 0.02 0.02 0.02 600 1150 210 150 90 90 major minerals the major minerals are those present in amounts larger than 5 g (a teaspoon). -a pound is about 454 g; thus only calcium and phosphorus appear in amounts larger than a pound. -trace minerals there are more than a dozen trace minerals, although only six are shown here. -0 100 200 300 400 500 600 700 800 900 1000 1100 1200 amount (g) the body s handling of minerals the minerals also differ from the vitamins in the amounts the body can absorb and in the extent to which they must be specially handled. -some minerals, such as potassium, are easily absorbed into the blood, transported freely, and readily excreted by the kidneys, much like the water-soluble vitamins. -other minerals, such as calcium, are more like fat-solu- ble vitamins in that they must have carriers to be absorbed and transported. -and, like some of the fat-soluble vitamins, minerals taken in excess can be toxic. -variable bioavailability the bioavailability of minerals varies. -some foods contain binders that combine chemically with minerals, preventing their ab- sorption and carrying them out of the body with other wastes. -examples of binders include phytates, which are found primarily in legumes and grains, and oxalates, which are present in rhubarb and spinach, among other foods. -these foods contain more minerals than the body actually receives for use. -nutrient interactions chapter 10 described how the presence or absence of one vitamin can affect another s absorption, metabolism, and excretion. -the same is true of the minerals. -the interactions between sodium and calcium, for example, cause both to be excreted when sodium intakes are high. -phosphorus binds with magnesium in the gi tract, so magnesium absorption is limited when phosphorus intakes are high. -these are just two examples of the interac- tions involving minerals featured in this chapter. -discussions in both this chap- ter and the next point out additional problems that arise from such interactions. -notice how often they reflect an excess of one mineral creating an inadequacy of another and how supplements not foods are most often to blame. -water and the major minerals 409 reminder: bioavailability refers to the rate at and the extent to which a nutrient is absorbed and used. -key fluid balance nutrients: sodium, potassium, chloride varied roles although all the major minerals help to maintain the body s fluid balance as described earlier, sodium, chloride, and potassium are most noted for that role. -for this reason, these three minerals are discussed first here. -later sec- tions describe the minerals most noted for their roles in bone growth and health calcium, phosphorus, and magnesium. -binders: chemical compounds in foods that combine with nutrients (especially minerals) to form complexes the body cannot absorb. -examples include phytates (fye-tates) and oxalates (ock-sa-lates). -410 chapter 12 ai for sodium: 1500 mg/day (19 50 yr) 1300 mg/day (51 70 yr) 1200 mg/day ((cid:5)70 yr) sodium: the principal cation in the extracellular fluids of the body; critical to the maintenance of fluid balance, nerve impulse transmissions, and muscle contractions. -salt sensitivity: a characteristic of individuals who respond to a high salt intake with an increase in blood pressure or to a low salt intake with a decrease in blood pressure. -in summary the major minerals are found in larger quantities in the body, whereas the trace minerals occur in smaller amounts. -minerals are inorganic elements that retain their chemical identities. -they usually receive special handling and regulation in the body, and they may bind with other substances or inter- act with other minerals, thus limiting their absorption. -sodium people have held salt (sodium chloride) in high regard throughout recorded his- tory. -we describe someone we admire as the salt of the earth and someone we consider worthless as not worth their salt. -even the word salary comes from the latin word for salt. -cultures vary in their use of salt, but most people find its taste innately appeal- ing. -salt brings its own tangy taste and enhances other flavors, most likely by sup- pressing the bitter flavors. -you can taste this effect for yourself: tonic water with its bitter quinine tastes sweeter with a little salt added. -sodium roles in the body sodium is the principal cation of the extracellular fluid and the primary regulator of its volume. -sodium also helps maintain acid-base balance and is essential to nerve impulse transmission and muscle contraction. -* sodium is readily absorbed by the intestinal tract and travels freely in the blood un- til it reaches the kidneys, which filter all the sodium out of the blood. -then, with great precision, the kidneys return to the bloodstream the exact amount of sodium the body needs. -normally, the amount excreted is approximately equal to the amount ingested on a given day. -when blood sodium rises, as when a person eats salted foods, thirst signals the person to drink until the appropriate sodium-to-water ratio is restored. -then the kidneys excrete both the excess water and the excess sodium together. -sodium recommendations diets rarely lack sodium, and even when intakes are low, the body adapts by reducing sodium losses in urine and sweat, thus making deficiencies unlikely. -sodium recommendations are set low enough to protect against high blood pressure, but high enough to allow an adequate intake of other nutrients with a typical diet. -because high sodium intakes correlate with high blood pressure, the upper level for adults is set at 2300 milligrams per day, slightly lower than the daily value used on food labels (2400 milligrams). -the average sodium in- take for adults in the united states exceeds the upper level and most adults will develop hypertension at some point in their lives. -sodium and hypertension for years, a high sodium intake was considered the primary factor responsible for high blood pressure. -then research pointed to salt (sodium chloride) as the dietary culprit. -salt has a greater effect on blood pressure than either sodium or chloride alone or in combination with other ions. -for some individuals, blood pressure increases in response to excesses in salt intake. -people most likely to have a salt sensitivity include those whose parents had high blood pressure, those with chronic kidney disease or diabetes, african americans, and people over 50 years of age. -** overweight people also appear to be particularly sensi- tive to the effect of salt on blood pressure. -for them, a high salt intake correlates strongly with heart disease, and salt restriction helps to lower their blood pressure. -in fact, a salt-restricted diet lowers blood pressure in people without hyperten- sion as well. -because reducing salt intake causes no harm and diminishes the risk * one of the ways the kidneys regulate acid-base balance is by excreting hydrogen ions (h+) in exchange for sodium ions (na+). -** compared with others, salt-sensitive individuals have elevated concentrations of renin in their blood. -dietary guidelines for americans 2005 consume less than 2300 mg (approximately 1 tsp of salt) of sodium per day. -of hypertension and heart disease, the 2005 dietary guidelines advise limiting daily salt intake to about 1 teaspoon (the equivalent of 2.3 grams or 2300 milligrams of sodium). -higher intakes seem to be well tolerated in most healthy people, how- ever. -the accompanying how to offers strategies for cutting salt (and therefore sodium) intake. -one diet plan, known as the dash (dietary approaches to stop hypertension) diet, also lowers blood pressure. -the dash approach emphasizes fruits, vegetables, and low-fat milk products; includes whole grains, nuts, poultry, and fish; and calls for reduced intakes of red meat, butter, and other high-fat foods. -the dash diet in combination with a reduced sodium intake is even more effective in lowering blood pressure than either strategy alone. -chapter 18 offers a complete discussion of hy- pertension and the dietary recommendations for its prevention and treatment. -sodium and bone loss (osteoporosis) a high salt intake is also associated with increased calcium excretion, but its influence on bone loss is less clear.9 in ad- dition, potassium may prevent the increase in calcium excretion caused by a high- salt diet.10 for these reasons, dietary advice to prevent bone loss parallel those suggested for hypertension a dash diet that is low in sodium and abundant in potassium-rich fruits and vegetables and calcium-rich low-fat milk products.11 sodium in foods in general, processed foods have the most sodium, whereas un- processed foods such as fresh fruits, vegetables, milk, and meats have the least. -in fact, as much as 75 percent of the sodium in people s diets comes from salt added to foods by manufacturers; about 15 percent comes from salt added during cooking and at the table; and only 10 percent comes from the natural content in foods. -how to cut salt (and sodium) intake most people eat more salt (and therefore sodium) than they need. -some people can lower their blood pressure by avoid- ing highly salted foods and removing the saltshaker from the table. -foods eaten without salt may seem less tasty at first, but with repetition, people can learn to enjoy the natural flavors of many unsalted foods. -strategies to cut salt intake in- clude: select fresh, unprocessed foods. -cook with little or no added salt. -prepare foods with sodium-free spices such as basil, bay leaves, curry, garlic, ginger, mint, oregano, pepper, rosemary, and thyme; lemon juice; vinegar; or wine. -add little or no salt at the table; taste foods before adding salt. -read labels with an eye open for sodium. -(see the glossary on p. 58 for terms used to describe the sodium contents of foods on labels.) -select low-salt or salt-free products when available. -use these foods sparingly: foods prepared in brine, such as pickles, olives, and sauerkraut salty or smoked meats, such as bologna, corned or chipped beef, bacon, frank- furters, ham, lunch meats, salt pork, sausage, and smoked tongue salty or smoked fish, such as anchovies, caviar, salted and dried cod, herring, sardines, and smoked salmon snack items such as potato chips, pret- zels, salted popcorn, salted nuts, and crackers condiments such as bouillon cubes; seasoned salts; msg; soy, teriyaki, worcestershire, and barbeque sauces; prepared horseradish, catsup, and mustard cheeses, especially processed types canned and instant soups water and the major minerals 411 salt (sodium chloride) is about 40% sodium. -1 g salt contributes 400 mg sodium 5 g salt = 1 tsp 1 tsp salt contributes 2000 mg sodium y r e g a m i k c o t s x e d n i / y c n e g a p s b i fresh herbs add flavor to a recipe without adding salt. -412 chapter 12 because processed foods may contain sodium without chloride, as in additives such as sodium bicarbonate or sodium saccharin, they do not always taste salty. -most people are surprised to learn that 1 ounce of cornflakes contains more sodium than 1 ounce of salted peanuts and that 1/2 cup of instant chocolate pudding con- tains still more. -(the peanuts taste saltier because the salt is all on the surface, where the tongue s sensors immediately pick it up.) -figure 12-10 shows that processed foods not only contain more sodium than their less processed counterparts but also have less potassium. -low potassium may be as significant as high sodium when it comes to blood pressure regulation, so processed foods have two strikes against them. -dietary guidelines for americans 2005 choose and prepare foods with little salt. -at the same time, consume potassium-rich foods, such as fruits and vegetables. -sodium deficiency if blood sodium drops, as may occur with vomiting, diarrhea, or heavy sweating, both sodium and water must be replenished. -under normal con- ditions of sweating due to physical activity, salt losses can easily be replaced later in the day with ordinary foods. -salt tablets are not recommended because too much salt, especially if taken with too little water, can induce dehydration. -during intense activities, such as ultra-endurance events, athletes can lose so much sodium and drink so much water that they develop hyponatremia the dangerous condition of having too little sodium in the blood. -chapter 14 offers details about hyponatremia and guidelines for ultra-endurance athletes. -figure 12-10 what processing does to the sodium and potassium contents of foods people who eat foods high in salt often happen to be eating fewer potassium-containing foods at the same time. -notice how potassium is lost and sodium is gained as foods become more processed, causing the potassium-to-sodium ratio to fall dramatically. -even when potassium isn t lost, the addition of sodium still lowers the potassium-to-sodium ratio. -limiting sodium intake may help in two ways, then by lowering blood pressure in salt-sensitive individuals and by indirectly raising potassium intakes in all individuals. -milks meats vegetables fruits grains milk (whole) roast beef fresh corn fresh peaches rolled oats unprocessed processed key: potassium sodium instant chocolate pudding chipped beef canned cream corn peach pie oat cereal ) l l a ( o i g u r r a f w e h t t a m sodium toxicity and excessive intakes the immediate symptoms of acute sodium toxicity are edema and hypertension, but such toxicity poses no problem as long as water needs are met. -prolonged excessive sodium intake may contribute to hypertension in some people, as explained earlier. -ul for sodium: 2300 mg/day water and the major minerals 413 in summary sodium is the main cation outside cells and one of the primary electrolytes re- sponsible for maintaining fluid balance. -dietary deficiency is rare, and ex- cesses may aggravate hypertension in some people. -for this reason, health professionals advise a diet moderate in salt and sodium. -the accompanying table summarizes information about sodium. -sodium adequate intake (ai) deficiency symptoms adults: 1500 mg/day (19 50 yr) 1300 mg/day (51 70 yr) 1200 mg/day (>70 yr) upper level adults: 2300 mg/day chief functions in the body maintains normal fluid and electrolyte balance; assists in nerve impulse transmission and muscle contraction muscle cramps, mental apathy, loss of appetite toxicity symptoms edema, acute hypertension significant sources table salt, soy sauce; moderate amounts in meats, milks, breads, and vegetables; large amounts in processed foods chloride the element chlorine (cl2) is a poisonous gas. -when chlorine reacts with sodium or hydrogen, however, it forms the negative chloride ion (cl ). -chloride, an essential nu- trient, is required in the diet. -chloride roles in the body chloride is the major anion of the extracellular fluids (outside the cells), where it occurs mostly in association with sodium. -chloride moves passively across membranes through channels and so also associates with potassium inside cells. -like sodium and potassium, chloride maintains fluid and electrolyte balance. -in the stomach, the chloride ion is part of hydrochloric acid, which maintains the strong acidity of the gastric juice. -one of the most serious consequences of vomiting is the loss of this acid from the stomach, which upsets the acid-base balance. -* such imbalances are commonly seen in bulimia nervosa, as described in highlight 8. chloride recommendations and intakes chloride is abundant in foods (es- pecially processed foods) as part of sodium chloride and other salts. -because the pro- portion of chloride in salt is greater than sodium, chloride recommendations are slightly higher than, but still equivalent to, those of sodium. -in other words, 3/4 tea- spoon of salt will deliver some sodium, more chloride, and still meet the ai for both. -chloride deficiency and toxicity diets rarely lack chloride. -chloride losses may occur in conditions such as heavy sweating, chronic diarrhea, and vomiting. -the only known cause of high blood chloride concentrations is dehydration due to reminder: the loss of acid can lead to alka- losis, an above-normal alkalinity in the blood and body fluids. -salt (sodium chloride) is about 60% chloride. -1 g salt contributes 600 mg chloride 5 g salt = 1 tsp 1 tsp salt contributes 3000 mg chloride * hydrochloric acid secretion into the stomach involves the addition of bicarbonate ions (base) to the (cid:3)) are neutralized by hydrogen ions (h+) from the gastric secretions plasma. -these bicarbonate ions (hco3 that are reabsorbed into the plasma. -when hydrochloric acid is lost during vomiting, these hydrogen ions are no longer available for reabsorption, and so, in effect, the concentrations of bicarbonate ions in the plasma are increased. -in this way, excessive vomiting of acidic gastric juices leads to metabolic alkalosis. -chloride (klo-ride): the major anion in the extracellular fluids of the body. -chloride is the ionic form of chlorine, cl(cid:3). -see appendix b for a description of the chlorine-to-chloride conversion. -414 chapter 12 reminder: the dash diet, used to lower blood pressure, emphasizes potassium-rich foods such as fruits and vegetables. -water deficiency. -in both cases, consuming ordinary foods and beverages can restore chloride balance. -in summary chloride is the major anion outside cells, and it associates closely with sodium. -in addition to its role in fluid balance, chloride is part of the stomach s hy- drochloric acid. -the accompanying table summarizes information on chloride. -chloride adequate intake (ai) deficiency symptoms adults: 2300 mg/day (19 50 yr) 2000 mg/day (51 70 yr) 1800 mg/day (>70 yr) upper level adults: 3600 mg/day chief functions in the body maintains normal fluid and electrolyte balance; part of hydrochloric acid found in the stom- ach, necessary for proper digestion do not occur under normal circumstances toxicity symptoms vomiting significant sources table salt, soy sauce; moderate amounts in meats, milks, eggs; large amounts in processed foods potassium like sodium, potassium is a positively charged ion. -in contrast to sodium, potas- sium is the body s principal intracellular cation, inside the body cells. -potassium roles in the body potassium plays a major role in maintaining fluid and electrolyte balance and cell integrity. -during nerve impulse transmission and muscle contraction, potassium and sodium briefly trade places across the cell mem- brane. -the cell then quickly pumps them back into place. -controlling potassium dis- tribution is a high priority for the body because it affects many aspects of homeostasis, including a steady heartbeat. -potassium recommendations and intakes potassium is abundant in all liv- ing cells, both plant and animal. -because cells remain intact unless foods are processed, the richest sources of potassium are fresh foods as figure 12-11 (p. 415) shows. -in contrast, most processed foods such as canned vegetables, ready-to-eat ce- reals, and luncheon meats contain less potassium and more sodium (recall figure 12-10, p. 412). -to meet the ai for potassium, most people need to increase their in- take of fruits and vegetables to five to nine servings daily. -potassium and hypertension diets low in potassium seem to play an impor- tant role in the development of high blood pressure. -low potassium intakes raise blood pressure, whereas high potassium intakes, especially when combined with low sodium intakes, appear to both prevent and correct hypertension.12 potassium- rich fruits and vegetables also appear to reduce the risk of stroke more so than can be explained by the reduction in blood pressure alone. -potassium deficiency potassium deficiency is characterized by an increase in blood pressure, salt sensitivity, kidney stones, and bone turnover. -as deficiency progresses, symptoms include irregular heartbeats, muscle weakness, and glucose intolerance. -potassium: the principal cation within the body s cells; critical to the maintenance of fluid balance, nerve impulse transmissions, and muscle contractions. -potassium toxicity potassium toxicity does not result from overeating foods high in potassium; therefore an upper level was not set. -it can result from overconsump- tion of potassium salts or supplements (including some energy fitness shakes ) and from certain diseases or treatments. -given more potassium than the body needs, the figure 12-11 potassium in selected foods see the how to on p. 329 for more information on using this figure. -food serving size (kcalories) 0 200 milligrams 400 600 800 water and the major minerals 415 c (31 kcal) c fresh (22 kcal) c cooked (22 kcal) c shredded raw (24 kcal) bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 1 2 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) broccoli carrots potato tomato juice banana orange strawberries watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: 1 2 squash, acorn 1 2 soybeans 1 (60 kcal) artichoke c low-fat 2% (101 kcal) c cooked (117 kcal) c baked (69 kcal) c cooked (149 kcal) c (76 kcal) the ai for potassium is 4700 mg per day. -potassium fresh fruits (purple), vegetables (green), legumes (brown), and meats (red) contribute potassium to the diet. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie kidneys accelerate their excretion. -if the gi tract is bypassed, however, and potas- sium is injected directly into a vein, it can stop the heart. -in summary potassium, like sodium and chloride, is an electrolyte that plays an important role in maintaining fluid balance. -potassium is the primary cation inside cells; fresh foods, notably fruits and vegetables, are its best sources. -the table below summarizes facts about potassium. -potassium adequate intake (ai) toxicity symptoms muscular weakness; vomiting; if given into a vein, can stop the heart significant sources all whole foods: meats, milks, fruits, vegetables, grains, legumes adults: 4700 mg/day chief functions in the body maintains normal fluid and electrolyte balance; facilitates many reactions; supports cell integrity; assists in nerve impulse transmission and muscle contractions deficiency symptomsa irregular heatbeat, muscular weakness, glucose intolerance adeficiency accompanies dehydration. -. -c n i s o i d u t s l a r a o p fresh foods, especially fruits and vegetables, provide potassium in abundance. -416 chapter 12 an example of a protein that calcium binds with and activates is calmodulin (cal-mod-you-lin). -one of calmodulin s roles is to activate the enzymes involved in breaking down glycogen, which releases energy for muscle contractions. -calcium: the most abundant mineral in the body; found primarily in the body s bones and teeth. -hydroxyapatite (high-drox-ee-app-ah-tite): crystals made of calcium and phosphorus. -mineralization: the process in which calcium, phosphorus, and other minerals crystallize on the collagen matrix of a growing bone, hardening the bone. -calcium calcium is the most abundant mineral in the body. -it receives much emphasis in this chapter and in the highlight that follows because an adequate intake helps grow a healthy skeleton in early life and minimize bone loss in later life. -calcium roles in the body ninety-nine percent of the body s calcium is in the bones (and teeth), where it plays two roles. -first, it is an integral part of bone structure, providing a rigid frame that holds the body upright and serves as attachment points for muscles, making motion possible. -second, it serves as a calcium bank, offering a readily available source of the mineral to the body fluids should a drop in blood calcium occur. -calcium in bones as bones begin to form, calcium salts form crystals, called hy- droxyapatite, on a matrix of the protein collagen. -during mineralization, as the crystals become denser, they give strength and rigidity to the maturing bones. -as a result, the long leg bones of children can support their weight by the time they have learned to walk. -many people have the idea that once a bone is built, it is inert like a rock. -actu- ally, the bones are gaining and losing minerals continuously in an ongoing process of remodeling. -growing children gain more bone than they lose, and healthy adults maintain a reasonable balance. -when withdrawals substantially exceed de- posits, problems such as osteoporosis develop (as described in highlight 12). -the formation of teeth follows a pattern similar to that of bones. -the turnover of minerals in teeth is not as rapid as in bone, however; fluoride hardens and sta- bilizes the crystals of teeth, opposing the withdrawal of minerals from them. -calcium in body fluids although only 1 percent of the body s calcium circulates in the extracellular and intracellular fluids, its presence there is vital to life. -many of its actions help to maintain normal blood pressure. -cells throughout the body can detect calcium in the extracellular fluids and re- spond accordingly. -for example, when the extracellular fluid contains too little cal- cium, the parathyroid glands release parathyroid hormone and the kidneys reabsorb calcium all in an effort to raise calcium levels. -extracellular calcium also participates in blood clotting. -the calcium in intracellular fluids binds to proteins within the cells and acti- vates them. -these proteins participate in the regulation of muscle contractions, the transmission of nerve impulses, the secretion of hormones, and the activation of some enzyme reactions. -calcium and disease prevention calcium may protect against hypertension. -for this reason, restricting sodium to treat hypertension is narrow advice, especially considering the success of the dash diet in lowering blood pressure. -the dash diet is not particularly low in sodium, but it is rich in calcium, as well as in magnesium and potassium. -as mentioned earlier, the dash diet, together with a reduced sodium intake, is more effective in lowering blood pressure than either strategy alone. -some research also suggests protective relationships between dietary calcium and blood cholesterol, diabetes, and colon cancer.13 highlight 12 explores calcium s role in preventing osteoporosis. -calcium and obesity calcium may also play a role in maintaining a healthy body weight.14 analyses of national survey data as well as small clinical studies show an inverse relationship between calcium intake and body fatness: the higher the cal- cium intake, the lower the body fatness.15 in particular, calcium from dairy foods, but not from supplements, seems to influence body weight.16 an adequate dietary cal- cium intake may help prevent excessive fat accumulation by stimulating hormonal action that targets the breakdown of stored fat.17 not all research suggests that cal- cium or dairy foods are associated with body weight.18 large, well-designed clinical studies are needed to clarify the effects of dietary calcium intake on body weight. -water and the major minerals 417 to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow. -figure 12-12 animated! -calcium balance blood calcium is regulated in part by vitamin d and two hormones calcitonin and parathyroid hormone. -bone serves as a reservoir when blood calcium is high and as a source of calcium when blood calcium is low. -osteoclasts break down bone and release calcium into the blood; osteoblasts build new bone using calcium from the blood. -rising blood calcium signals the thyroid gland to secrete calcitonin. -* thyroid parathyroid (embedded in the thyroid) falling blood calcium signals the parathyroid glands to secrete parathyroid hormone. -1 2 3 4 calcitonin inhibits the activation of vitamin d. calcitonin prevents calcium reabsorption in the kidneys. -calcitonin limits calcium absorption in the intestines. -calcitonin inhibits osteoclast cells from breaking down bone, preventing the release of calcium. -calcitonin parathyroid hormone 1 vitamin d activation 1 vitamin d 2 2 kidneys 3 4 intestines 3 4 1 2 3 4 parathyroid hormone stimulates the activation of vitamin d. vitamin d and parathyroid hormone stimulate calcium reabsorption in the kidneys. -vitamin d enhances calcium absorption in the intestines. -vitamin d and parathyroid hormone stimulate osteoclast cells to break down bone, releasing calcium into the blood. -all these actions lower blood calcium levels, which inhibits calcitonin secretion. -bones all these actions raise blood calcium levels, which inhibits parathyroid hormone secretion. -*calcitonin plays a major role in defending infants and young children against the dangers of rising blood calcium that can occur when regular feedings of milk deliver large quantities of calcium to a small body. -in contrast, calcitonin plays a relatively minor role in adults because their absorption of calcium is less efficient and their bodies are larger, making elevated blood calcium unlikely. -calcium balance calcium homeostasis involves a system of hormones and vitamin d. whenever blood calcium falls too low or rises too high, three organ systems respond: the intestines, bones, and kidneys. -figure 12-12 illustrates how vitamin d and two hor- mones parathyroid hormone and calcitonin return blood calcium to normal. -the calcium in bone provides a nearly inexhaustible bank of calcium for the blood. -the blood borrows and returns calcium as needed so that even with a di- etary deficiency, blood calcium remains normal even as bone calcium diminishes (see figure 12-13, p. 418). -blood calcium changes only in response to abnormal regulatory control, not to diet. -a person can have an inadequate calcium intake for years and suffer no noticeable symptoms. -only later in life does it become appar- ent that bone integrity has been compromised. -blood calcium above normal results in calcium rigor: the muscles contract and cannot relax. -similarly, blood calcium below normal causes calcium tetany also characterized by uncontrolled muscle contraction. -these conditions do not reflect a dietary excess or lack of calcium; they are caused by a lack of vita- min d or by abnormal secretion of the regulatory hormones. -a chronic dietary de- ficiency of calcium, or a chronic deficiency due to poor absorption over the years, parathyroid hormone: a hormone from the parathyroid glands that regulates blood calcium by raising it when levels fall too low; also known as parathormone (pair-ah- thor-moan). -calcitonin (kal-seh-toe-nin): a hormone secreted by the thyroid gland that regulates blood calcium by lowering it when levels rise too high. -calcium rigor: hardness or stiffness of the muscles caused by high blood calcium concentrations. -calcium tetany (tet-ah-nee): intermittent spasm of the extremities due to nervous and muscular excitability caused by low blood calcium concentrations. -418 chapter 12 figure 12-13 maintaining blood cal- cium from the diet and from the bones depletes the savings account in the bones. -again: the bones, not the blood, are robbed by a calcium deficiency. ) -h t o b ( 6 8 9 1 , s e r r e n i m e n o b j m o r f r e t s p m e d d i v a d calcium absorption many factors affect calcium absorption, but on average, adults absorb about 25 percent of the calcium they ingest. -the stomach s acidity helps to keep calcium soluble, and vitamin d helps to make the calcium-binding protein needed for absorption. -(this explains why calcium-rich milk is the best food for vitamin d fortification.) -whenever calcium is needed, the body increases its production of the calcium- binding protein to improve calcium absorption. -the result is obvious in the case of a pregnant woman, who absorbs 50 percent of the calcium from the milk she drinks. -similarly, growing children and teens absorb 50 to 60 percent of the calcium they consume. -then, when bone growth slows or stops, absorption falls to the adult level of about 25 percent. -in addition, absorption becomes more efficient during times of inadequate intakes. -many of the conditions that enhance calcium absorption inhibit its absorption when they are absent. -for example, sufficient vitamin d supports absorption, and a deficiency impairs it. -in addition, fiber, in general, and the binders phytate and oxalate, in particular, interfere with calcium absorption, but their effects are rela- tively minor in typical u.s. diets. -vegetables with oxalates and whole grains with phytates are nutritious foods, of course, but they are not useful calcium sources. -the margin note presents factors that influence calcium balance. -calcium recommendations and sources calcium is unlike most other nutrients in that hormones maintain its blood concen- tration regardless of dietary intake. -as figure 12-13 shows, when calcium intake is high, the bones benefit; when intake is low, the bones suffer. -calcium recommenda- tions are therefore based on the amount needed to retain the most calcium in bones. -by retaining the most calcium possible, the bones can develop to their fullest poten- tial in size and density their peak bone mass within genetic limits. -calcium recommendations because obtaining enough calcium during growth helps to ensure that the skeleton will be strong and dense, recommendations have been set high at 1300 milligrams daily for adolescents up to the age of 18 years. -between the ages of 19 and 50, recommendations are lowered to 1000 milligrams a day; for older adults, recommendations are raised again to 1200 milligrams a day to minimize the bone loss that tends to occur later in life. -some authorities advocate as much as 1500 milligrams a day for women over 50. many people in the united states and canada, particularly women, have calcium intakes far below current recommendations. -high intakes of calcium from supplements may have adverse effects such as kidney stone for- mation.19 for this reason, an upper level has been established (see inside front cover). -high intakes of both dietary protein and sodium increase calcium losses, but whether these losses impair bone development remains unclear. -in the case of protein, high intakes of either animal or plant proteins may be problematic, but the effects are minimized by the beneficial effects of other nutrients in the food and diet for exam- ple, by the potassium in legumes and the calcium in milk.20 in establishing an adequate intake (ai) for calcium, the dri committee considered these nutrient inter- actions and did not adjust dietary recommendations based on this information. -calcium in milk products figure 12-14 shows that calcium is found most abun- dantly in a single class of foods milk. -the person who doesn t like to drink milk may prefer to eat cheese or yogurt. -alternatively, milk and milk products can be con- cealed in foods. -powdered fat-free milk can be added to casseroles, soups, and other mixed dishes during preparation; 5 heaping tablespoons offer the equivalent of 1 cup of milk. -this simple step is an excellent way for older women not only to obtain extra calcium, but more protein, vitamins, and minerals as well. -it is especially difficult for children who don t drink milk to meet their calcium needs.21 children who don t drink milk have lower calcium intakes and poorer bone with an adequate intake of calcium-rich food, blood calcium remains normal . -. -. -with a dietary deficiency, blood calcium still remains normal . -. -. -. -. -. -and bones deposit calcium. -the result is strong, dense bones. -. -. -. -because bones give up calcium to the blood. -the result is weak, osteoporotic bones. -factors that enhance calcium absorption: stomach acid vitamin d lactose (in infants only) factors that inhibit calcium absorption: lack of stomach acid vitamin d deficiency high phosphorus intake phytates (in seeds, nuts, grains) oxalates (in beet greens, rhubarb, spinach, sweet potatoes) suggested daily amounts: young children (2 to 8 yr): 2 c older children, teenagers, and all adults: 3 c calcium-binding protein: a protein in the intestinal cells, made with the help of vitamin d, that facilitates calcium absorption. -peak bone mass: the highest attainable bone density for an individual, developed during the first three decades of life. -figure 12-14 calcium in selected foods see the how to on p. 329 for more information on using this figure. -food serving size (kcalories) 0 100 200 300 400 500 600 700 800 900 1000 1100 1200 milligrams water and the major minerals 419 bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice banana orange strawberries watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd)a ground beef, lean chicken breast c (31 kcal) c fresh (22 kcal) 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) c (76 kcal) tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: sardines, with bonesb bok choy (chinese cabbage) almonds 3 oz canned (176 kcal) 1 2 c cooked (10 kcal) 1 oz (167 kcal) calcium as in the riboflavin figure, milk and milk products (white) dominate the calcium figure. -most people need at least three selections from the milk group to meet recommendations. -avalues based on products containing added calcium salts; the calcium in 1 2 c soybeans is about 2 3 as much as in 1 2 c tofu. -bif bones are discarded, calcium declines dramatically. -ai for women 19 50 ai for women 51+ ai for men 19 50 ai for men 51+ key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie health than those who drink milk regularly.22 the consequences of drinking too lit- tle milk during childhood and adolescence persist into adulthood. -women who sel- dom drank milk as children or teenagers have lower bone density and greater risk of fractures than those who drank milk regularly.23 it is possible for people who do not drink milk to obtain adequate calcium, but only if they carefully select other cal- cium-rich foods. -calcium in other foods many people, for a variety of reasons, cannot or do not drink milk. -some cultures do not use milk in their cuisines; some vegetarians exclude milk as well as meat; and some people are allergic to milk protein or are lactose intol- erant. -others simply do not enjoy the taste of milk. -these people need to find non- milk sources of calcium to help meet their calcium needs. -some brands of tofu, corn tortillas, some nuts (such as almonds), and some seeds (such as sesame seeds) can supply calcium for the person who doesn t use milk products. -a slice of most breads contains only about 5 to 10 percent of the calcium found in milk, but it can be a ma- jor source for people who eat many slices because the calcium is well absorbed. -among the vegetables, mustard and turnip greens, bok choy, kale, parsley, wa- tercress, and broccoli are good sources of available calcium. -so are some seaweeds such as the nori popular in japanese cooking. -some dark green, leafy vegetables notably spinach and swiss chard appear to be calcium-rich but actually provide little, if any, calcium to the body because of the binders they contain. -it would take 8 cups of spinach containing six times as much calcium as 1 cup of milk to de- liver the equivalent in absorbable calcium. -people with lactose intolerance may be able to consume small quantities of milk, as chapter 4 explains. -420 chapter 12 figure 12-15 bioavailability of calcium from selected foods 50% absorbed 30% absorbed cauliflower, watercress, brussels sprouts, rutabaga, kale, mustard greens, bok choy, broccoli, turnip greens milk, calcium-fortified soy milk, calcium-set tofu, cheese, yogurt, calcium- fortified foods and beverages 20% absorbed almonds, sesame seeds, pinto beans, sweet potatoes 5% absorbed spinach, rhubarb, swiss chard to practice estimating calcium intake, log on to www.thomsonedu.com/login, go to chapter 12, then go to how to. -milk and milk products are notorious for their calcium, but calcium-set tofu, bok choy, kale, calcium-fortified orange juice, and broccoli are also rich in calcium. -with the exception of foods such as spinach that contain calcium binders, how- ever, the calcium content of foods is usually more important than bioavailability. -consequently, recognizing that people eat a variety of foods containing calcium, the dri committee did not consider calcium bioavailability when setting recommenda- tions. -figure 12-15 ranks selected foods according to their calcium bioavailability. -oysters are also a rich source of calcium, as are small fish eaten with their bones, such as canned sardines. -many asians prepare a stock from bones that helps account for their adequate calcium intake without the use of milk. -they soak the cracked bones from chicken, turkey, pork, or fish in vinegar and then slowly boil the bones until they become soft. -the bones release calcium into the acidic broth, and most of the vinegar boils off. -cooks then use the stock, which contains more than 100 milligrams of calcium per tablespoon, in place of water to prepare soups, vegetables, and rice. -similarly, cooks in the navajo tribe use an ash pre- pared from the branches and needles of the juniper tree in their recipes. -one tea- spoon of juniper ash provides about as much calcium as a cup of milk. -some mineral waters provide as much as 500 milligrams of calcium per liter, of- fering a convenient way to meet both calcium and water needs.24 similarly, calcium- fortified orange juice and other fruit and vegetable juices allow a person to obtain both calcium and vitamins easily. -other examples of calcium-fortified foods include high-calcium milk (milk with extra calcium added) and calcium-fortified cereals. -fortified juices and foods help consumers increase calcium intakes, but depending on the calcium sources, the bioavailability may be significantly less than quantities listed on food labels.25 the how to below describes a shortcut method for estimat- ing your calcium intake. -highlight 12 discusses calcium supplements. -how to estimate your calcium intake most dietitians have developed useful short- cuts to help them estimate nutrient intakes and see inadequacies in the diet. -they can tell at a glance whether a day s meals fall short of calcium recommendations, for example. -to estimate calcium intakes, keep two bits of information in mind: a cup of milk provides about 300 mil- ligrams of calcium. -adults need between 1000 and 1200 milligrams of calcium per day, which represents 3 to 4 cups of milk or the equivalent: 1000 mg (cid:6) 300 mg/c (cid:4) 31 3 c 1200 mg (cid:6) 300 mg/c (cid:4) 4 c if a person drinks 3 to 4 cups of milk a day, it s easy to see that calcium needs are being met. -if not, it takes some detective work to identify the other sources and estimate total calcium intake. -to estimate a person s daily calcium intake, use this shortcut, which compares the calcium in calcium-rich foods to the calcium content of milk. -the calcium in a cup of milk is assigned 1 point, and the goal is to attain 3 to 4 points per day. -foods are given points as follows: 1 c milk, yogurt, or fortified soy milk or 11 2 oz cheese (cid:4) 1 point o i g g u r r a f w e h t t a m 4 oz canned fish with bones (sardines) (cid:4) 1 point 1 c ice cream, cottage cheese, or calcium-rich vegetable (see the text) (cid:4) 1 2 point then, because other foods also contribute small amounts of calcium, together they are given a point. -well-balanced diet containing a variety of foods (cid:4) 1 point now consider a day s meals with calcium in mind. -cereal with 1 cup of milk for breakfast (1 point for milk), a ham and cheese sub sandwich for lunch (1 point for cheese), and a cup of broccoli and lasagna for dinner (1 2 point for calcium- rich vegetable and 1 point for cheese in lasagna) plus 1 point for all other foods eaten that day adds up to 41 2 points. -this shortcut estimate indicates that calcium recommendations have been met, and a diet analysis of these few foods reveals a calcium intake of over 1000 milligrams. -by knowing the best sources of each nutrient, you can learn to scan the day s meals and quickly see if you are meeting your daily goals. -water and the major minerals 421 a generalization that has been gaining strength throughout this book is supported by the information given here about calcium. -a balanced diet that supplies a vari- ety of foods is the best plan to ensure adequacy for all essential nutrients. -all food groups should be included, and none should be overemphasized. -in our culture, cal- cium intake is usually inadequate wherever milk is lacking in the diet whether through ignorance, poverty, simple dislike, fad dieting, lactose intolerance, or al- lergy. -by contrast, iron is usually lacking whenever milk is overemphasized, as chapter 13 explains. -calcium deficiency a low calcium intake during the growing years limits the bones ability to reach their optimal mass and density. -most people achieve a peak bone mass by their late 20s, and dense bones best protect against age-related bone loss and fractures (see figure 12-16). -all adults lose bone as they grow older, beginning between the ages of 30 and 40. when bone losses reach the point of causing fractures under common, everyday stresses, the condition is known as osteoporosis. -osteoporosis affects more than 44 million people in the united states, mostly older women. -unlike many diseases that make themselves known through symptoms such as pain, shortness of breath, skin lesions, tiredness, and the like, osteoporosis is silent. -the body sends no signals saying bones are losing their calcium and, as a result, their integrity. -blood samples offer no clues because blood calcium remains normal regardless of bone content, and measures of bone density are not routinely taken. -highlight 12 suggests strategies to protect against bone loss, of which eating cal- cium-rich foods is only one. -figure 12-16 phases of bone development throughout life the active growth phase occurs from birth to approximately age 20. the next phase of peak bone mass development occurs between the ages of 12 and 30. the final phase, when bone resorption exceeds formation, begins between the ages of 30 and 40 and continues through the remainder of life. -peak bone mass bone density 10 20 30 40 50 60 70 80 years active growth bone loss in summary most of the body s calcium is in the bones where it provides a rigid structure and a reservoir of calcium for the blood. -blood calcium participates in muscle contraction, blood clotting, and nerve impulses, and it is closely regulated by a system of hormones and vitamin d. calcium is found predominantly in milk and milk products, but some other foods including certain vegetables and tofu also provide calcium. -even when calcium intake is inadequate, blood calcium remains normal, but at the expense of bone loss, which can lead to osteoporo- sis. -calcium s roles, deficiency symptoms, and food sources are summarized on the next page. -(continued) osteoporosis (os-tee-oh-pore-oh-sis): a disease in which the bones become porous and fragile due to a loss of minerals; also called adult bone loss. -osteo = bone porosis = porous 422 chapter 12 phosphorus: a major mineral found mostly in the body s bones and teeth. -calcium (continued) adequate intake (ai) deficiency symptoms adults: 1000 mg/day (19 50 yr) 1200 mg/day (>51 yr) stunted growth in children; bone loss (osteo- porosis) in adults upper level adults: 2500 mg/day chief functions in the body mineralization of bones and teeth; also in- volved in muscle contraction and relaxation, nerve functioning, blood clotting, blood pressure toxicity symptoms constipation; increased risk of urinary stone formation and kidney dysfunction; interference with absorption of other minerals significant sources milk and milk products, small fish (with bones), calcium-set tofu, greens (bok choy, broccoli, chard, kale), legumes phosphorus phosphorus is the second most abundant mineral in the body. -about 85 percent of it is found combined with calcium in the hydroxyapatite crystals of bones and teeth. -phosphorus roles in the body phosphorus salts (phosphates) are found not only in bones and teeth, but in all body cells as part of a major buffer system (phos- phoric acid and its salts). -phosphorus is also part of dna and rna and is therefore necessary for all growth. -phosphorus assists in energy metabolism. -many enzymes and the b vitamins be- come active only when a phosphate group is attached. -atp itself, the energy cur- rency of the cells, uses three phosphate groups to do its work. -lipids containing phosphorus as part of their structures (phospholipids) help to transport other lipids in the blood. -phospholipids are also the major structural com- ponents of cell membranes, where they control the transport of nutrients into and out of the cells. -some proteins, such as the casein in milk, contain phosphorus as part of their structures (phosphoproteins). -phosphorus recommendations and intakes because phosphorus is com- monly found in almost all foods, dietary deficiencies are unlikely. -as figure 12-17 shows, foods rich in proteins are the best sources of phosphorus. -milk and cheese con- tribute about one-fourth of the phosphorus in the u.s. diet. -in the past, researchers emphasized the importance of an ideal calcium-to- phosphorus ratio from the diet to support calcium metabolism, but there is little or no evidence to support this concept. -the quantities of calcium and phosphorus in the diet are far more important than their ratio to each other. -a high phosphorus intake has been blamed for bone loss when, in fact, a low calcium intake not a phosphorus toxicity or an improper ratio is responsible. -research shows that the displacement of milk in the diet by cola drinks, not the phosphoric acid content of the beverages, has adverse effects on bone. -no adverse effects of high dietary phos- phorus intakes have been reported; still, an upper level has been established (see inside front cover). -in summary phosphorus accompanies calcium both in the crystals of bone and in many foods such as milk. -phosphorus is also important in energy metabolism, as part of phospholipids, and as part of the genetic materials dna and rna. -the summary table on the next page lists functions of, and other information about, phosphorus. -(continued) figure 12-17 phosphorus in selected foods see the how to on p. 329 for more information on using this figure. -food serving size (kcalories) 0 100 200 300 400 500 600 700 milligrams water and the major minerals 423 c (31 kcal) c fresh (22 kcal) 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice banana orange strawberries watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: liver almonds candy bar 3 oz (184 kcal) 1 oz (165 kcal) 2.2 oz (278 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) c (76 kcal) rda for adults phosphorus protein-rich sources, such as milk (white), meats (red), and legumes (brown), provide abundant phosphorus. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats miscellaneous best sources per kcalorie phosphorus rda adults: 700 mg/day upper level deficiency symptoms muscular weakness, bone paina toxicity symptoms adults (19 70 yr): 4000 mg/day chief functions in the body mineralization of bones and teeth; part of every cell; important in genetic material, part of phospholipids, used in energy transfer and in buffer systems that maintain acid-base balance calcification of nonskeletal tissues, particularly the kidneys significant sources all animal tissues (meat, fish, poultry, eggs, milk) adietary deficiency rarely occurs, but some drugs can bind with phosphorus making it unavailable and resulting in bone loss that is characterized by weakness and pain. -magnesium magnesium barely qualifies as a major mineral: only about 1 ounce of magne- sium is present in the body of a 130-pound person. -over half of the body s magne- sium is in the bones. -much of the rest is in the muscles and soft tissues, with only 1 magnesium: a cation within the body s cells, active in many enzyme systems. -424 chapter 12 reminder: a catalyst is a compound that facilitates chemical reactions without itself being changed in the process. -percent in the extracellular fluid. -as with calcium, bone magnesium may serve as a reservoir to ensure normal blood concentrations. -magnesium roles in the body in addition to maintaining bone health, mag- nesium acts in all the cells of the soft tissues, where it forms part of the protein- making machinery and is necessary for energy metabolism. -it participates in hundreds of enzyme systems. -a major role of magnesium is as a catalyst in the reaction that adds the last phosphate to the high-energy compound atp, making it essential to the body s use of glucose; the synthesis of protein, fat, and nucleic acids; and the cells membrane transport systems. -together with calcium, mag- nesium is involved in muscle contraction and blood clotting: calcium promotes the processes, whereas magnesium inhibits them. -this dynamic interaction be- tween the two minerals helps regulate blood pressure and lung function. -like many other nutrients, magnesium supports the normal functioning of the im- mune system. -magnesium intakes average dietary magnesium estimates for u.s. adults fall below recommendations. -dietary intake data, however, do not include the contribu- tion made by water. -in areas with hard water, the water contributes both calcium and magnesium to daily intakes. -mineral waters noted earlier for their calcium con- tent may also be magnesium-rich and can be important sources of this mineral for those who drink them.26 bioavailability of magnesium from mineral water is about 50 percent, but it improves when the water is consumed with a meal.27 the brown bars in figure 12-18 indicate that legumes, seeds, and nuts make sig- nificant magnesium contributions. -magnesium is part of the chlorophyll molecule, so leafy green vegetables are also good sources. -magnesium deficiency even with average magnesium intakes below recom- mendations, deficiency symptoms rarely appear except with diseases. -magnesium deficiency may develop in cases of alcohol abuse, protein malnutrition, kidney dis- orders, and prolonged vomiting or diarrhea. -people using diuretics may also show symptoms. -a severe magnesium deficiency causes a tetany similar to the calcium tetany described earlier. -magnesium deficiencies also impair central nervous system activity and may be responsible for the hallucinations experienced during alcohol withdrawal. -magnesium and hypertension magnesium is critical to heart function and seems to protect against hypertension and heart disease.28 interestingly, people liv- ing in areas of the country with hard water, which contains high concentrations of calcium and magnesium, tend to have low rates of heart disease. -with magnesium deficiency, the walls of the arteries and capillaries tend to constrict a possible ex- planation for the hypertensive effect. -magnesium toxicity magnesium toxicity is rare, but it can be fatal. -the upper level for magnesium applies only to nonfood sources such as supplements or mag- nesium salts. -in summary like calcium and phosphorus, magnesium supports bone mineralization. -magnesium is also involved in numerous enzyme systems and in heart func- tion. -it is found abundantly in legumes and leafy green vegetables and, in some areas, in water. -the table below offers a summary. -magnesium rda upper level men (19 30 yr): 400 mg/day adults: 350 mg nonfood magnesium/day women (19 30 yr): 310 mg/day (continued) figure 12-18 magnesium in selected foods see the how to on p. 329 for more information on using this figure. -food serving size (kcalories) 0 50 100 150 200 250 300 350 400 milligrams water and the major minerals 425 bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots potato tomato juice banana orange strawberries c (31 kcal) c fresh (22 kcal) 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg c (76 kcal) 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: halibut cashews artichoke 3 oz baked (199 kcal) 1 oz (161 kcal) 1 (60 kcal) magnesium (continued) rda for men 19 30 rda for women 19 30 magnesium legumes (brown) are a rich source of magnesium. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie chief functions in the body deficiency symptoms toxicity symptoms bone mineralization, building of protein, enzyme action, normal muscle contraction, nerve im- pulse transmission, maintenance of teeth, and functioning of immune system weakness; confusion; if extreme, convulsions, bizarre muscle movements (especially of eye and face muscles), hallucinations, and difficulty in swallowing; in children, growth failurea from nonfood sources only; diarrhea, alkalosis, dehydration significant sources nuts, legumes, whole grains, dark green vegeta- bles, seafood, chocolate, cocoa aa still more severe deficiency causes tetany, an extreme, prolonged contraction of the muscles similar to that caused by low blood calcium. -sulfate sulfate is the oxidized form of the mineral sulfur, as it exists in food and water. -the body s need for sulfate is easily met by a variety of foods and beverages. -in addition, the body receives sulfate from the amino acids methionine and cysteine found in di- etary proteins. -these sulfur-containing amino acids help determine the contour of protein molecules. -the sulfur-containing side chains in cysteine molecules can link to each other, forming disulfide bridges, which stabilize the protein structure. -(see the drawing of insulin with its disulfide bridges on p. -184.) -skin, hair, and nails contain some of the body s more rigid proteins, which have a high sulfur content. -because the body s sulfate needs are easily met with normal protein intakes, there is no recommended intake for sulfate. -deficiencies do not occur when diets contain protein. -only when people lack protein to the point of severe deficiency will they lack the sulfur-containing amino acids. -sulfate: the oxidized form of sulfur. -sulfur: a mineral present in the body as part of some proteins. -426 chapter 12 in summary like the other nutrients, minerals actions are coordinated to get the body s work done. -the major minerals, especially sodium, chloride, and potassium, influence the body s fluid balance; whenever an anion moves, a cation moves always maintaining homeostasis. -sodium, chloride, potassium, calcium, and magnesium are key members of the team of nutrients that direct nerve impulse transmission and muscle contraction. -they are also the primary nutrients involved in regulating blood pres- sure. -phosphorus and magnesium participate in many reactions involving glucose, fatty acids, amino acids, and the vita- mins. -calcium, phosphorus, and magnesium combine to form the structure of the bones and teeth. -each major mineral also plays other specific roles in the body. -(see the summary table below.) -the major minerals mineral and chief functions sodium maintains normal fluid and electrolyte balance; assists in nerve impulse transmission and muscle contraction chloride maintains normal fluid and electrolyte balance; part of hydrochloric acid found in the stomach, necessary for proper digestion potassium maintains normal fluid and electrolyte balance; facilitates many reactions; supports cell integrity; assists in nerve impulse transmission and muscle contractions calcium mineralization of bones and teeth; also involved in muscle contraction and relaxation, nerve functioning, blood clotting, and blood pressure phosphorus mineralization of bones and teeth; part of every cell; important in genetic material, part of phospholipids, used in energy transfer and in buffer systems that maintain acid- base balance magnesium bone mineralization, building of protein, enzyme action, normal muscle contraction, nerve impulse transmission, maintenance of teeth, and functioning of immune system sulfate as part of proteins, stabilizes their shape by forming disulfide bridges; part of the vitamins biotin and thiamin and the hormone insulin deficiency symptoms toxicity symptoms significant sources muscle cramps, mental apathy, loss of appetite edema, acute hypertension do not occur under normal circumstances vomiting table salt, soy sauce; moderate amounts in meats, milks, breads, and vegetables; large amounts in processed foods table salt, soy sauce; moderate amounts in meats, milks, eggs; large amounts in processed foods irregular heartbeat, muscular weakness, glucose intolerance muscular weakness; vomiting; if given into a vein, can stop the heart all whole foods; meats, milks, fruits, vegetables, grains, legumes stunted growth in children; bone loss (osteo- porosis) in adults muscular weakness, bone paina constipation; increased risk of urinary stone for- mation and kidney dys- function; interference with absorption of other minerals milk and milk products, small fish (with bones), tofu, greens (bok choy, broccoli, chard), legumes calcification of nonskeletal tissues, particularly the kidneys all animal tissues (meat, fish, poultry, eggs, milk) weakness; confusion; if extreme, convulsions, bizarre muscle movements (especially of eye and face muscles), hallucinations, and diffi- culty in swallowing; in children, growth failureb from nonfood sources only; diarrhea, alkalosis, dehydration nuts, legumes, whole grains, dark green vegetables, seafood, chocolate, cocoa none known; protein deficiency would occur first toxicity would occur only if sulfur-containing amino acids were eaten in excess; this (in ani- mals) suppresses growth all protein-containing foods (meats, fish, poultry, eggs, milk, legumes, nuts) adietary deficiency rarely occurs, but some drugs can bind with phosphorus making it unavailable and resulting in bone loss that is characterized by weakness and pain. -ba still more severe deficiency causes tetany, an extreme, prolonged contraction of the muscles similar to that caused by low blood calcium. -water and the major minerals 427 with all of the tasks these minerals perform, they are of great importance to life. -consuming enough of each of them every day is easy, given a variety of foods from each of the food groups. -whole-grain breads supply magnesium; fruits, vegetables, and legumes provide magnesium and potassium, too; milks offer calcium and phosphorus; meats offer phosphorus and sulfate as well; all foods provide sodium and chloride, with excesses being more problematic than inadequacies. -the mes- sage is quite simple and has been repeated throughout this text: for an adequate intake of all the nutrients, including the major minerals, choose different foods from each of the five food groups. -and drink plenty of water. -nutrition portfolio www.thomsonedu.com/thomsonnow many people may miss the mark when it comes to drinking enough water to keep their bodies well hydrated or obtaining enough calcium to promote strong bones; in contrast, sodium intakes often exceed those recommended for health. -describe your strategy for ensuring that you drink plenty of water about 8 glasses every day. -explain the importance of selecting and preparing foods with less salt. -determine whether you drink at least 3 glasses of milk or get the equivalent in calcium every day. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 12, then to nutrition on the net. -www.whymilk.com find tips and recipes for including more milk in the diet: search for minerals at the american dietetic association site: www.eatright.org learn about sodium in foods and on food labels from the food and drug administration: www.fda.gov/fdac/ foodlabel/sodium.html learn about the benefits of calcium from the national dairy council: www.nationaldairycouncil.org nutrition calculations for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 12, then to nutrition calculations. -these problems give you an appreciation for the minerals in foods. -be sure to show your calculations (see p. 430 for answers). -2. learn to appreciate calcium-dense foods. -the foods in the accompanying table are ranked in order of their calcium contents per serving. -1. for each of these minerals, note the unit of measure: calcium potassium sodium magnesium phosphorus a. which foods offer the most calcium per kcalorie? -to calculate calcium density, divide calcium (mg) by energy (kcal). -record your answer in the table (round your answers); the first one is done for you. -428 chapter 12 b. the top five items ranked in order of calcium con- tents per serving are sardines > milk > cheese > salmon > broccoli. -what are the top five items in order of calcium content per kcalorie? -calcium density (mg/kcal) 1.85 food sardines, 3 oz canned milk, fat-free, 1 c cheddar cheese, 1 oz salmon, 3 oz canned broccoli, cooked from fresh, chopped, 1 2 c sweet potato, baked in skin, 1 ea cantaloupe melon, 1 2 whole-wheat bread, 1 slice apple, 1 medium sirloin steak, lean, 3 oz calcium (mg) energy (kcal) 325 301 204 182 36 32 29 21 15 9 176 85 114 118 22 140 93 64 125 171 this information should convince you that milk, milk products, fish eaten with their bones, and dark green vegetables are the best choices for calcium. -3. a. consider how the rate of absorption influences the amount of calcium available for the body s use. -use figure 12-15 on p. 420 to determine how much study questions calcium the body actually receives from the foods listed in the accompanying table by multiplying the milligrams of calcium in the food by the percentage absorbed. -the first one is done for you. -b. to appreciate how the absorption rate influences the amount of calcium available to the body, com- pare broccoli with almonds. -which provides more calcium in foods and to the body? -c. to appreciate how the calcium content of foods influences the amount of calcium available to the body, compare cauliflower with milk. -how much cauliflower would a person have to eat to receive an equivalent amount of calcium as from 1 cup of milk? -how does your answer change when you account for differences in their absorption rates? -food cauliflower, 1 2 c cooked, fresh broccoli, 1 2 c cooked, fresh milk, 1 c 1% low-fat almonds, 1 oz spinach, 1 c raw calcium in the food (mg) absorption rate (%) calcium in the body (mg) 50 5 10 36 300 75 55 to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -8. list calcium s roles in the body. -how does the body keep blood calcium constant regardless of intake? -(pp. -416 418) these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. list the roles of water in the body. -(p. 397) 2. list the sources of water intake and routes of water ex- cretion. -(pp. -398 399) 3. what is adh? -where does it exert its action? -what is aldosterone? -how does it work? -(p. 401) 4. how does the body use electrolytes to regulate fluid balance? -(pp. -402 406) 5. what do the terms major and trace mean when describ- ing the minerals in the body? -(pp. -408 409) 6. describe some characteristics of minerals that distin- guish them from vitamins. -(pp. -408 409) 7. what is the major function of sodium in the body? -de- scribe how the kidneys regulate blood sodium. -is a di- etary deficiency of sodium likely? -why or why not? -(pp. -410 413) 9. name significant food sources of calcium. -what are the consequences of inadequate intakes? -(pp. -408 421) 10. list the roles of phosphorus in the body. -discuss the relationships between calcium and phosphorus. -is a dietary deficiency of phosphorus likely? -why or why not? -(pp. -422 423) 11. state the major functions of chloride, potassium, magne- sium, and sulfur in the body. -are deficiencies of these nutrients likely to occur in your own diet? -why or why not? -(pp. -422 423) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 430. -1. the body generates water during the: a. buffering of acids. -b. dismantling of bone. -c. metabolism of minerals. -d. breakdown of energy nutrients. -2. regulation of fluid and electrolyte balance and acid-base 6. which would provide the most potassium? -water and the major minerals 429 balance depends primarily on the: a. kidneys. -b. intestines. -c. sweat glands. -d. specialized tear ducts. -3. the distinction between the major and trace minerals reflects the: a. ability of their ions to form salts. -b. amounts of their contents in the body. -c. importance of their functions in the body. -d. capacity to retain their identity after absorption. -4. the principal cation in extracellular fluids is: a. sodium. -b. chloride. -c. potassium. -d. phosphorus. -5. the role of chloride in the stomach is to help: a. support nerve impulses. -b. convey hormonal messages. -c. maintain a strong acidity. -d. assist in muscular contractions. -a. bologna b. potatoes c. pickles d. whole-wheat bread 7. calcium homeostasis depends on: a. vitamin k, aldosterone, and renin. -b. vitamin k, parathyroid hormone, and renin. -c. vitamin d, aldosterone, and calcitonin. -d. vitamin d, calcitonin, and parathyroid hormone. -8. calcium absorption is hindered by: a. lactose. -b. oxalates. -c. vitamin d. d. stomach acid. -9. phosphorus assists in many activities in the body, but not: a. energy metabolism. -b. the clotting of blood. -c. the transport of lipids. -d. bone and teeth formation. -10. most of the body s magnesium can be found in the: a. bones. -b. nerves. -c. muscles. -d. extracellular fluids. -references 1. j. w. gardner, death by water intoxication, metabolism 87 (2002): 2008-2012. military medicine 167 (2002): 432-434. -2. f. manz and a. wentz, hydration status in the united states and germany, nutrition reviews 63 (2005): s55-s62. -3. m. n. sawka, s. n. cheuvront, and r. carter iii, human water needs, nutrition reviews 63 (2005): s30-s39. -4. b. m. popkin and coauthors, a new pro- posed guidance system for beverage con- sumption in the united states, american journal of clinical nutrition 83 (2006): 529-542. -5. committee on dietary reference intakes, dietary reference intakes for water, potassium, sodium, chloride, and sulfate (washington, d.c.: national academies press, 2004), pp. -120-121. -6. f. manz and a. wentz, the importance of good hydration for the prevention of chronic diseases, nutrition reviews 63 (2005): s2-s5. -7. p. ritz and g. berrut, the importance of good hydration for day-to-day health, nutrition reviews 63 (2005): s6-s13. -8. k. m. o shaughnessy and f. e. karet, salt handling and hypertension, annual review of nutrition 26 (2006): 343-365. -9. m. harrington and k. d. cashman, high salt intake appears to increase bone resorp- tion in postmenopausal women but high potassium intake ameliorates this adverse effect, nutrition reviews 61 (2003): 179-183. -10. d. e. sellmeyer, m. schloetter, and a. se- bastin, potassium citrate prevents increased urine calcium excretion and bone resorp- tion induced by a high sodium chloride diet, journal of clinical endocrinology and 11. p. lin and coauthors, the dash diet and sodium reduction improve markers of bone turnover and calcium metabolism in adults, journal of nutrition 133 (2003): 3130-3136. -12. c. a. nowson and coauthors, blood pres- sure response to dietary modifications in free-living individuals, journal of nutrition 134 (2004): 2322-2329. -13. s. c. larsson and coauthors, calcium and dairy food intakes are inversely associated with colorectal cancer risk in the cohort of swedish men, american journal of clinical nutrition 83 (2006): 667-673; a. flood and coauthors, calcium from diet and supple- ments is associated with reduced risk of colorectal cancer in a prospective cohort of women, cancer epidemiology, biomarkers, and prevention 14 (2005): 126-132; u. peters and coauthors, calcium intake and colorectal adenoma in a us colorectal cancer early detection program, american journal of clinical nutrition 80 (2004): 1358-1365; e. cho and coauthors, dairy foods, calcium, and colorectal cancer: a pooled analysis of 10 cohort studies, journal of the national cancer institute 96 (2004): 1015-1022; m. jacqmain and coauthors, calcium intake, body composition, and lipoprotein-lipid concentrations, american journal of clinical nutrition 77 (2003): 1448-1452. -14. s. j. parikh and j. a. yanovski, calcium and adiposity, american journal of clinical nutri- tion 77 (2003): 281-287; d. teegarden, calcium intake and reduction in weight or fat mass, journal of nutrition 133 (2003): 249s-251s; r. p. heaney, k. m. davies, and m. j. barger-lux, calcium and weight: clinical studies, journal of the american college of nutrition 21 (2002): 152-155. -15. r. j. loos and coauthors, calcium intake is associated with adiposity in black and white men and white women of the heritage family study, journal of nutrition 134 (2004): 1772-1778; jacqmain and coauthors, 2003; teegarden, 2003; heaney, davies, and barger-lux, 2002. -16. j. k. lorenzen and coauthors, calcium supplementation for 1 y does not reduce body weight or fat mass in young girls, american journal of clinical nutrition 83 (2006): 18-23; m. b. zemel and coauthors, dietary calcium and dairy products acceler- ate weight and fat loss during energy restric- tion in obese adults, american journal of clinical nutrition 75 (2002): 342s. -17. m. b. zemel, mechanisms of dairy modula- tion of adiposity, journal of nutrition 133 (2003): 252s-256s. -18. s. n. rajpathak and coauthors, calcium and dairy intakes in relation to long-term weight gain in us men, american journal of clinical nutrition 83 (2006): 559-566; c. w. gunther and coauthors, dairy products do not lead to alterations in body weight or fat mass in young women in a 1-y intervention, ameri- can journal of clinical nutrition 81 (2005): 751-756; s. i. barr, increased dairy product or calcium intake: is body weight or compo- sition affected in humans? -journal of nutri- tion 133 (2003): 245s-248s. -19. r. d. jackson and coauthors, calcium plus vitamin d supplementation and the risk of fractures, new england journal of medicine 354 (2006): 669-683. -23. f. r. greer, n. f. krebs, and the committee on nutrition, optimizing bone health and calcium intakes of infants, children, and adolescents, pediatrics 117 (2006) 578-585; h. j. kalkwarf, j. c. khoury, and b. p. lan- phear, milk intake during childhood and adolescence, adult bone density, and osteo- porotic fractures in us women, american journal of clinical nutrition 77 (2003): 257-265. -24. r. p. heaney, absorbability and utility of calcium in mineral waters, american journal of clinical nutrition 84 (2006): 371-374. -25. r. p. heaney and coauthors, calcium fortifi- cation systems differ in bioavailability, journal of the american dietetic association 105 (2005): 807-809. -26. galan and coauthors, 2002. -27. m. sabatier and coauthors, meal effect on magnesium bioavailability from mineral water in healthy women, american journal of clinical nutrition 75 (2002): 65-71. -28. s. h. jee and coauthors, the effect of mag- nesium supplementation on blood pressure: a meta-analysis of randomized clinical trials, american journal of hypertension 15 (2002): 691-696. b. the almonds offer more than twice as much calcium per serving, but an equivalent amount after absorption. -c. to equal the 300 milligrams provided by milk, a person would need to eat 15 cups of cauliflower (300 mg/c milk (cid:6) 10 mg/1 2 c cauliflower (cid:4) 30 1 2 c or 15 c). -after considering the better absorption rate of cauli- flower, a person would need to eat 9 cups of cauli- flower (5 mg/1 2 c or 10 mg/c; 90 mg (cid:6) 10 mg/c (cid:4) 9 c) to match the 90 milligrams available to the body from milk after absorption. -the better absorption rate reduced the quantity of cauliflower significantly, but that s still a lot of cauliflower. -study questions (multiple choice) 1. d 9. b 2. a 3. b 4. a 5. c 6. b 7. d 8. b 10. a 430 chapter 12 20. l. k. massey, dietary animal and plant protein and human bone health: a whole foods approach, journal of nutrition 133 (2003): 862s-865s. -21. x. gao and coauthors, meeting adequate intake for dietary calcium without dairy foods in adolescents aged 9 to 18 years (national health and nutrition examina- tion survey 2001-2002), journal of the american dietetic association 106 (2006): 1759-1765. -22. r. e. black and coauthors, children who avoid drinking cow milk have low dietary calcium intakes and poor bone health, american journal of clinical nutrition 76 (2002): 675-680. answers nutrition calculations 1. calcium: mg magnesium: mg phosphorus: mg potassium: mg sodium: mg 2. a. food sardines, 3 oz canned milk, fat-free, 1 c cheddar cheese, 1 oz salmon, 3 oz canned broccoli, cooked from fresh, chopped, 1 2 c sweet potato, baked in skin, 1 ea cantaloupe melon, 1 2 whole-wheat bread, 1 slice apple, 1 medium sirloin steak, lean, 3 oz calcium density (mg/kcal) 325 mg (cid:6) 176 kcal (cid:4) 1.85 mg/kcal 301 mg (cid:6) 85 kcal (cid:4) 3.54 mg/kcal 204 mg (cid:6) 114 kcal (cid:4) 1.79 mg/kcal 182 mg (cid:6) 118 kcal (cid:4) 1.54 mg/kcal 36 mg (cid:6) 22 kcal (cid:4) 1.64 mg/kcal 32 mg (cid:6) 140 kcal (cid:4) 0.23 mg/kcal 29 mg (cid:6) 93 kcal (cid:4) 0.31 mg/kcal 21 mg (cid:6) 64 kcal (cid:4) 0.33 mg/kcal 15 mg (cid:6) 125 kcal (cid:4) 0.12 mg/kcal 9 mg (cid:6) 171 kcal (cid:4) 0.05 mg/kcal b. ranked by calcium density (calcium per kcalorie): milk > sardines > cheese > broccoli > salmon 3. a. food cauliflower, 1 2 c cooked, fresh broccoli, 1 2 c cooked, fresh milk, 1 c 1% low-fat almonds, 1 oz spinach, 1 c raw calcium in food (mg) (cid:7)(cid:7) absorption rate (%) (cid:4) calcium in the body (mg) 10 mg (cid:7) 0.50 (cid:4) 5 mg (or more) 36 mg (cid:7) 0.50 (cid:4) 18 mg (or more) 300 mg (cid:7) 0.30 (cid:4) 90 mg 75 mg (cid:7) 0.20 (cid:4) 15 mg 55 mg (cid:7) 0.05 (cid:4) 3 mg (or less) highlight 12 osteoporosis and calcium osteoporosis becomes apparent during the later years, but it develops much earlier and without warning. -few people are aware that their bones are being robbed of their strength. -the problem often first becomes evident when someone s hip suddenly gives way. -people say, she fell and broke her hip, but in fact the hip may have been so fragile that it broke before she fell. -even bumping into a table may be enough to shatter a porous bone into fragments so numerous and scattered that they cannot be reassem- bled. -removing them and replacing them with an artificial joint requires major surgery. -an estimated 300,000 people in the united states are hospitalized each year because of hip fractures related to osteoporosis. -about a fourth die of complications within a year. -a fourth of those who survive will never walk or live independently again. -their quality of life slips downward. -this highlight examines osteoporosis, one of the most preva- lent diseases of aging, affecting more than 44 million people in the united states most of them women over 50.1 it reviews the many factors that contribute to the 1.5 million breaks in the bones of the hips, vertebrae, wrists, arms, and ankles each year. -and it presents strategies to reduce the risks, paying special atten- tion to the role of dietary calcium. -bone development and disintegration i s e g a m y t t e g / c s i d o t o h p bone has two compartments: the outer, hard shell of cortical bone and the inner, lacy matrix of trabecular bone. -(the glossary defines these and other bone-related terms.) -both can lose minerals, but in different ways and at different rates. -the photograph on p. 432 shows a human leg bone sliced length- wise, exposing the lacy, calcium-containing crystals of trabecular bone. -these crystals give up calcium to the blood when the diet runs short, and they take up calcium again when the supply is plentiful (review figure 12-13 on p. 418). -for people who have eaten calcium-rich foods throughout the bone- forming years of their youth, these deposits make bones dense and provide a rich reservoir of calcium. -surrounding and protecting the trabecular bone is a dense, ivorylike exterior shell the cortical bone. -cortical bone com- poses the shafts of the long bones, and a thin cortical shell caps the end of the bone, too. -both compartments confer strength on bone: cortical bone provides the sturdy outer wall, and trabecular bone provides support along the lines of stress. -the two types of bone play different roles in calcium balance and osteoporosis. -supplied with blood vessels and metabolically g lossary bone meal or powdered bone: crushed or ground bone preparations intended to supply calcium to the diet. -calcium from bone is not well absorbed and is often contaminated with toxic minerals such as arsenic, mercury, lead, and cadmium. -bone density: a measure of bone strength. -when minerals fill the bone matrix (making it dense), they give it strength. -cortical bone: the very dense and comprises the shaft of a long bone. -dolomite: a compound of minerals (calcium magnesium carbonate) found in limestone and marble. -dolomite is powdered and is sold as a calcium-magnesium supplement. -however, it may be contaminated with toxic minerals, is not well absorbed, and interacts adversely with absorption of other esssential minerals. -bone tissue that forms the outer shell surrounding trabecular bone oyster shell: a product made from the powdered shells of oysters that is sold as a calcium supplement, but it is not well absorbed by the digestive system. -trabecular (tra-beck-you-lar) bone: the lacy inner structure of calcium crystals that supports the bone s structure and provides a calcium storage bank. -type i osteoporosis: osteoporosis characterized by rapid bone losses, primarily of trabecular bone. -type ii osteoporosis: osteoporosis characterized by gradual losses of both trabecular and cortical bone. -reminder: osteoporosis is a disease characterized by porous and fragile bones. -antacids are medications used to relieve indigestions by neutralizing acid in the stomach. -calcium- containing preparations (such as tums) contain available calcium. -antacids with aluminum or magnesium hydroxides (such as rolaids) can accelerate calcium losses. -431 432 highlight 12 active, trabecular bone is sensitive to hormones that govern day- to-day deposits and withdrawals of calcium. -it readily gives up minerals whenever blood calcium needs replenishing. -losses of trabecular bone start becoming significant for men and women in their 30s, although losses can occur whenever calcium with- drawals exceed deposits. -cortical bone also gives up calcium, but slowly and at a steady pace. -cortical bone losses typically begin at about age 40 and continue slowly but surely thereafter. -losses of trabecular and cortical bone reflect two types of os- teoporosis, which cause two types of bone breaks. -type i osteo- porosis involves losses of trabecular bone (see figure h12-1). -these losses sometimes exceed three times the expected rate, and bone breaks may occur suddenly. -trabecular bone becomes so fragile that even the body s own weight can overburden the spine vertebrae may suddenly disintegrate and crush down, painfully pinching major nerves. -wrists may break as bone ends weaken, and teeth may loosen or fall out as the trabecular bone of the jaw recedes. -women are most often the victims of this type of osteoporosis, outnumbering men six to one. -in type ii osteoporosis, the calcium of both cortical and tra- becular bone is drawn out of storage, but slowly over the years. -as old age approaches, the vertebrae may compress into wedge shapes, forming what is often called a dowager s hump, the pos- ture many older people assume as they grow shorter. -figure h12-2 (p. 433) shows the effect of compressed spinal bone on a woman s height and posture. -because both the cortical shell and the trabecular interior weaken, breaks most often occur in the hip, as mentioned in the introductory paragraph. -a woman is twice as likely as a man to suffer type ii osteoporosis. -figure h12-1 healthy and osteoporotic trabecular bones t i d e o t o h p / f f l o w g n u o y d i v a d using a dexa (dual-energy x-ray absorpiometry) scan to measure bone mineral density identifies osteoporosis, determines risks for fractures, and tracks responses to treatment. -table h12-1 summarizes the differences between the two types of osteoporosis. -physicians can diagnose osteoporosis and assess the risk of bone fractures by measuring bone density using dual-energy x-ray absorptiometry (dexa scan) or ultrasound. -they also consider risk factors that predict bone fractures, including age, personal and family history of fracture, bmi, and physical inactivity.2 table h12-2 summarizes the major risk factors and protective factors for osteo- ) h t o b ( 6 8 9 1 , s e r r e n i m e n o b j m o r f r e t s p m e d d i v a d y b n o i s s i m r e p i l i m n o j g f o y s e t r u o c trabecular bone is the lacy network of calcium-containing crystals that fills the interior. -cortical bone is the dense, ivorylike bone that forms the exterior shell. -electron micrograph of healthy trabecular bone. -electron micrograph of trabecular bone affected by osteoporosis. -figure h12-2 loss of height in a woman caused by osteoporosis the woman on the left is about 50 years old. -on the right, she is 80 years old. -her legs have not grown shorter. -instead, her back has lost length due to collapse of her spinal bones (vertebrae). -collapsed vertebrae cannot protect the spinal nerves from pressure that causes excruciating pain. -6 inches lost 50 years old 80 years old table h12-1 types of osteoporosis compared osteoporosis and calcium 433 porosis. -the more risk factors that apply to a person, the greater the chances of bone loss. -notice that several risk factors that are influen- tial in the development of osteoporosis such as age, gender, and genetics cannot be changed. -other risk factors such as diet, phys- ical activity, body weight, smoking, and alcohol use are personal behaviors that can be changed. -by eating a calcium-rich, well- balanced diet, being physically active, abstaining from smoking, and drinking alcohol in moderation (if at all), people can defend them- selves against osteoporosis. -these decisions are particularly important for those with other risk factors that cannot be changed. -whether a person develops osteoporosis seems to depend on the interactions of several factors, including nutrition. -the strongest predictor of bone density is age: osteoporosis is respon- sible for 90 percent of the hip fractures in women and 80 percent in men over the age of 65. age and bone calcium two major stages of life are critical in the development of osteo- porosis. -the first is the bone-acquiring stage of childhood and adolescence. -the second is the bone-losing decades of late adult- hood (especially in women after menopause). -the bones gain strength and density all through the growing years and into young adulthood. -as people age, the cells that build bone gradu- ally become less active, but those that dismantle bone continue working. -the result is that bone loss exceeds bone formation. -some bone loss is inevitable, but losses can be curtailed by maxi- mizing bone mass. -table h12-2 risk factors and protective factors for osteoporosis risk factors older age low bmi protective factors younger age high bmi caucasian, asian, or hispanic african american heritage heritage cigarette smoking no smoking alcohol consumption in excess alcohol consumption in moderation sedentary lifestyle regular weight-bearing exercise type i type ii use of glucocorticoids or use of diuretics other name age of onset bone loss fracture sites gender incidence primary causes postmenopausal osteoporosis 50 to 70 years old trabecular bone wrist and spine 6 women to 1 man rapid loss of estrogen in women following menopause; loss of testosterone in men with advancing age senile osteoporosis 70 years and older both trabecular and cortical bone hip 2 women to 1 man reduced calcium absorption, increased bone mineral loss, increased propensity to fall anticonvulsants female gender male gender maternal history of osteoporosis bone density assessment and fracture or personal history of fracture estrogen deficiency in women (amenorrhea or menopause, especially early or surgically induced); testosterone deficiency in men treatment (if necessary) use of estrogen therapy lifetime diet inadequate in calcium and vitamin d lifetime diet rich in calcium and vitamin d 434 highlight 12 maximizing bone mass to maximize bone mass, the diet must deliver an adequate supply of calcium during the first three decades of life. -children and teens who get enough calcium and vitamin d have denser bones than those with inadequate intakes.3 with little or no calcium from the diet, the body must depend on bone to supply calcium to the blood bone mass diminishes, and bones lose their density and strength. -when people reach the bone-losing years of middle age, those who formed dense bones during their youth have the advan- tage. -they simply have more bone starting out and can lose more before suffering ill effects. -figure h12-3 demonstrates this effect. -minimizing bone loss not only does dietary calcium build strong bones in youth, but it remains important in protecting against losses in the later years. -unfortunately, calcium intakes of older adults are typically low, and calcium absorption declines after menopause.4 the kidneys do not activate vitamin d as well as they did earlier (recall that active vita- min d enhances calcium absorption). -also, sunlight is needed to form vitamin d, and many older people spend little or no time outdoors in the sunshine. -for these reasons, and because intakes of vitamin d are typically low anyway, blood vitamin d declines. -some of the hormones that regulate bone and calcium metab- olism also change with age and accelerate bone mineral with- drawal. -* together, these age-related factors contribute to bone loss: inefficient bone remodeling, reduced calcium intakes, im- paired calcium absorption, poor vitamin d status, and hormonal changes that favor bone mineral withdrawal. -figure h12-3 bone losses over time compared peak bone mass is achieved by age 30. women gradually lose bone mass until menopause, when losses accelerate dramatically and then gradually taper off. -woman a entered adulthood with enough calcium in her bones to last a lifetime. -s s a m e n o b danger zone a osteoporosis woman b had less bone mass starting out and so suffered ill effects from bone loss later on. -age 30 menopause age 60 time apeople with a moderate degree of bone mass reduction are said to have osteopenia and are at increased risk of fractures. -source: data from committee on dietary reference intakes, dietary reference intakes for calcium, phospho- rus, magnesium, vitamin d, and fluoride (washington, d.c.: national academy press, 1997), pp. -71 145. gender and hormones after age, gender is the next strongest predictor of osteoporosis. -men have greater bone density than women at maturity, and women have greater losses than men in later life. -consequently, men develop bone problems about 10 years later than women, and women account for four out of five cases of osteoporosis.5 menopause imperils women s bones. -bone dwindles rapidly when the hormone estrogen diminishes and menstruation ceases. -women may lose up to 20 percent of their bone mass dur- ing the six to eight years following menopause. -eventually, losses taper off so that women again lose bone at the same rate as men their age. -losses of bone minerals continue throughout the re- mainder of a woman s lifetime, but not at the free-fall pace of the menopause years (review figure h12-3). -rapid bone losses also occur when young women s ovaries fail to produce enough estrogen, causing menstruation to cease. -in some cases, diseased ovaries are to blame and must be removed; in oth- ers, the ovaries fail to produce sufficient estrogen because the women suffer from anorexia nervosa and have unreasonably re- stricted their body weight (see highlight 8). -the amenorrhea and low body weights explain much of the bone loss seen in these young women, even years after diagnosis and treatment. -estrogen therapy can help nonmenstruating women prevent further bone loss and reduce the incidence of fractures.6 because estrogen ther- apy may increase the risks for breast cancer, women must carefully weigh any potential benefits against the possible dangers.7 the two main classes of drugs used to prevent or treat osteoporosis are an- tiresorptive agents that block bone resorption by inhibiting osteo- clast activity (examples include raloxifene, alendronate, risedronate, and calcitonin) and anabolic agents that stimulate bone formation by acting on osteoblasts (an ex- ample is parathyroid hormone).8** a combination of these drugs or of hormone replacement and a drug may be most beneficial.9 some women who choose not to use estrogen therapy turn to soy as an alternative treatment. -interestingly, the phytochemicals commonly found in soybeans mimic the actions of estrogen in the body. -when natural estrogen is lacking, as after menopause, these phytochemicals may step in to stimulate estrogen-sensitive tissues. -by way of this action, soy and its phytochemicals may help to pre- vent the rapid bone losses of the menopause years.10 re- search is far from conclusive, but some evidence suggests that soy may indeed offer some protection.11 if estrogen deficiency is a major cause of osteoporosis in women, what is the cause of bone loss in men? -the male sex hormone testosterone appears to play a role. -men with low levels of testosterone, as occurs after re- *among the hormones suggested as influential are parathyroid hormone, calcitonin, and estrogen. -**raloxifene (rah-lox-ih-feen) is a selective estrogen-receptor modulator (serm), marketed as evista; alendronate (a-len- droe-nate) is a bisphosphonate, marketed as fosamax; rise- dronate (rih-seh-droe-nate) is a bisphosphonate, marketed as actonel; and calcitonin is a hormone, marketed as calcimar and miacalcin. -moval of diseased testes or when testes lose function with aging, suffer more fractures. -treatment for men with osteoporosis in- cludes testosterone replacement therapy. -thus both male and fe- male sex hormones participate in the development and treatment of osteoporosis. -genetics and ethnicity osteoporosis may, in part, be hereditary, and family history of osteo- porosis or fracture is a risk factor. -the exact role of genetics is un- clear, but it most likely influences both the peak bone mass achieved during growth and the bone loss incurred during the later years. -the extent to which a given genetic potential is realized, however, de- pends on many outside factors. -diet and physical activity, for exam- ple, can maximize peak bone density during growth, whereas alcohol and tobacco abuse can accelerate bone losses later in life. -risks of osteoporosis appear to run along racial lines and reflect genetic differences in bone development. -african americans, for example, seem to use and conserve calcium more efficiently than caucasians.12 consequently, even though their calcium intakes are typically lower, black people have denser bones than white people do. -greater bone density expresses itself in less bone loss, fewer fractures, and a lower rate of osteoporosis among blacks.13 fractures, for example, are about twice as likely in white women age 65 or older as in black women. -other ethnic groups have a high risk of osteoporosis. -asians from china and japan, mexican americans, hispanic people from central and south america, and inuit people from st. lawrence island typically have lower bone density than caucasians. -one might expect that these groups would suffer more bone frac- tures, but this is not always the case. -again, genetic differences may explain why. -asians, for example, generally have small, com- pact hips, which makes them less susceptible to fractures. -findings from around the world demonstrate that although a person s genes may lay the groundwork for bone health, environ- mental factors influence the genes ultimate expression. -diet in general, and calcium in particular, are among those environmen- tal factors. -others include physical activity, body weight, smok- ing, and alcohol. -importantly, all of these factors are within a person s control. -physical activity and body weight physical activity may be the single most important factor support- ing bone growth during adolescence.14 muscle strength and bone strength go together. -when muscles work, they pull on the bones, stimulating them to develop more trabeculae and grow denser. -the hormones that promote new muscle growth also fa- vor the building of bone. -as a result, active bones are denser and stronger than sedentary bones.15 to keep bones healthy, a person should engage in weight training or weight-bearing endurance activities (such as tennis osteoporosis and calcium 435 i s b r o c / e n i w e l b o r and jogging or vigorous walking) regularly.16 regu- lar physical activity com- bined with an adequate intake helps to calcium maximize bone density in adolescence.17 adults can also maximize and maintain bone density with a regular program of weight training. -even past menopause, when most women are los- ing bone, weight training improves bone density.18 heavier body weights and weight gains place a similar stress on the bones and promote their density. -in fact, weight losses reduce bone density and increase the risk of fractures in part because energy restriction diminishes calcium absorption and com- promises calcium balance.19 as mentioned in highlight 8, the com- bination of underweight, severely restricted energy intake, extreme daily exercise, and amenorrhea reliably predicts bone loss. -strength training helps to build strong bones. -smoking and alcohol add bone damage to the list of ill consequences associated with smoking. -the bones of smokers are less dense than those of non- smokers even after controlling for differences in age, body weight, and physical activity habits.20 fortunately, the damaging effects can be reversed with smoking cessation. -blood indicators of beneficial bone activity are apparent six weeks after a person stops smoking.21 in time, bone density is similar for former smok- ers and nonsmokers. -people who abuse alcohol often suffer from osteoporosis and experience more bone breaks than others. -several factors appear to be involved. -alcohol enhances fluid excretion, leading to ex- cessive calcium losses in the urine; upsets the hormonal balance required for healthy bones; slows bone formation, leading to lower bone density; stimulates bone breakdown; and increases the risk of falling. -dietary calcium bone strength later in life depends most on how well the bones were built during childhood and adolescence. -adequate calcium nutrition during the growing years is essential to achieving opti- mal peak bone mass. -simply put, growing children who do not get enough calcium do not have strong bones.22 neither do adults who did not get enough calcium during their childhood and adolescence.23 to that end, the dri committee recommends 1300 milligrams of calcium per day for everyone 9 through 18 436 highlight 12 years of age. -unfortunately, few girls meet the recommendations for calcium during these bone-forming years. -(boys generally ob- tain intakes close to those recommended because they eat more food.) -consequently, most girls start their adult years with less- than-optimal bone density. -as adults, women rarely meet their recommended intakes of 1000 to 1200 milligrams from food. -some authorities suggest 1500 milligrams of calcium for post- menopausal women who are not receiving estrogen, but they warn that intakes exceeding 2500 milligrams a day could cause health problems. -other nutrients much research has focused on calcium, but other nutrients sup- port bone health, too.24 adequate protein protects bones and re- duces the likelihood of hip fractures.25 as mentioned earlier, vitamin d is needed to maintain calcium metabolism and optimal bone health.26 supplementation with vitamin d reduces bone loss and the risk of fractures.27 vitamin k decreases bone turnover and protects against hip fractures.28 the minerals magnesium and potassium also help to maintain bone mineral density. -vita- min a is needed in the bone-remodeling process, but too much vitamin a may be associated with osteoporosis.29 omega-3 fatty acids may help preserve bone integrity.30 additional research points to the bone benefits not of a specific nutrient, but of a diet rich in fruits and vegetables.31 in contrast, diets containing too much salt are associated with bone losses.32 clearly, a well- balanced diet that depends on all the food groups to supply a full array of nutrients is central to bone health. -a perspective on supplements bone health depends, in part, on calcium. -people who do not consume milk products or other calcium-rich foods in amounts that provide even half the recommended calcium should consider consulting a registered dietitian who can assess the diet and sug- gest food choices to correct any inadequacies. -for those who are unable to consume enough calcium-rich foods, taking calcium supplements may help to enhance bone density and protect against bone loss.33 selecting a calcium supplement requires a little investigative work to sort through the many options. -before examining cal- cium supplements, recognize that multivitamin-mineral pills con- tain little or no calcium. -the label may list a few milligrams of calcium, but remember that the recommended intake is a gram or more for adults. -calcium supplements are typically sold as compounds of cal- cium carbonate (common in antacids and fortified chocolate candies), citrate, gluconate, lactate, malate, or phosphate. -these supplements often include magnesium, vitamin d, or both. -in ad- dition, some calcium supplements are made from bone meal, oyster shell, or dolomite (limestone). -many calcium supple- ments, especially those derived from these natural products, con- tain lead which impairs health in numerous ways, as chapter 13 points out.34 fortunately, calcium interferes with the absorption and action of lead in the body. -the first question to ask is how much calcium the supplement provides. -most calcium supplements provide between 250 and 1000 milligrams of calcium. -to be safe, total calcium intake from both foods and supplements should not exceed 2500 milligrams a day. -read the label to find out how much a dose supplies. -unless the label states otherwise, supplements of calcium carbonate are 40 percent calcium; those of calcium citrate are 21 percent; lac- tate, 13 percent; and gluconate, 9 percent. -select a low-dose sup- plement, and take it several times a day rather than taking a large-dose supplement all at once. -taking supplements in doses of 500 milligrams or less improves absorption. -small doses also help ease the gi distress (constipation, intestinal bloating, and exces- sive gas) that sometimes accompanies calcium supplement use. -the next question to ask is how well the body absorbs and uses the calcium from various supplements. -most healthy people absorb calcium equally well (and as well as from milk) from any of these supplements: calcium carbonate, citrate, or phosphate. -more important than supplement solubility is tablet disintegra- tion. -when manufacturers compress large quantities of calcium into small pills, the stomach acid has difficulty penetrating the pill. -to test a supplement s ability to dissolve, drop it into a 6- ounce cup of vinegar, and stir occasionally. -a high-quality formu- lation will dissolve within half an hour. -finally, people who choose supplements must take them reg- ularly. -furthermore, consideration should be given to the best time to take the supplements. -to circumvent adverse nutrient in- teractions, take calcium supplements between, not with, meals. -(importantly, do not take calcium supplements with iron supple- ments or iron-rich meals; calcium inhibits iron absorption.) -to en- hance calcium absorption, take supplements with meals. -if such contradictory advice drives you crazy, reconsider the benefits of food sources of calcium. -most experts agree that foods are the best source of most nutrients. -some closing thoughts unfortunately, many of the strongest risk factors for osteoporosis are beyond people s control: age, gender, and genetics. -but sev- eral strategies are still effective for prevention.35 first, ensure an optimal peak bone mass during childhood and adolescence by eating a balanced diet rich in calcium and engaging in regular physical activity. -then, maintain that bone mass by continuing those healthy diet and activity habits, abstaining from cigarette smoking, and using alcohol moderately, if at all. -finally, minimize bone loss by maintaining an adequate nutrition and exercise reg- imen, and, for women, consult a physician about calcium sup- plements or other drug therapies that may be effective both in preventing bone loss and in restoring lost bone. -the reward is the best possible chance of preserving bone health throughout life. -osteoporosis and calcium 437 nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 12, then to highlights nutrition on the net. -visit the national institutes of health osteoporosis and related bone diseases national resource center: www.osteo.org search for falls and fractures at the national institute obtain additional information from the national on aging: www.nih.gov/nia osteoporosis foundation: www.nof.org references 1. u.s. department of health and human services, bone health and osteoporosis: a report of the surgeon general, (rockville, md. -: u.s. department of health and human services, office of the surgeon general, 2004). -2. l. g. raisz, screening for osteoporosis, new england journal of medicine 353 (2005): 164- 171. -3. f. r. greer, n. f. krebs, and the committee on nutrition, optimizing bone health and calcium intakes of infants, children, and adolescents, pediatrics 117 (2006) 578-585. -4. b. e. c. nordin and coauthors, effect of age on calcium absorption in postmenopausal women, american journal of clinical nutrition 80 (2004): 998-1002. -5. j. m. campion and m. j. maricic, osteo- porosis in men, american family physician 67 (2003): 1521-1526. -6. h. j. kloosterboer and a. g. ederveen, pros and cons of existing treatment modalities in osteoporosis: a comparison between ti- bolone, serms and estrogen (+/- progesto- gen) treatments, journal of steroid biochemistry and molecular biology 83 (2002): 157-165; r. a. sayegh and p. g. stubblefield, bone metabolism and the perimenopause overview, risk factors, screening, and osteo- porosis preventive measures, obstetrics and gynecology clinics of north america 29 (2002): 495-510. -7. r. t. chlebowski and coauthors, influence of estrogen plus progestin on breast cancer and mammography in healthy postmenopausal women: the women s health initiative randomized trial, journal of the american medical association 289 (2003): 3243-3253; c. g. solomon and r. g. dluhy, rethinking postmenopausal hor- mone therapy, new england journal of medi- cine 348 (2003): 579-580; writing group for the women s health initiative investigators, risks and benefits of estrogen plus progestin in healthy postmenopausal women: princi- pal results from the women s health initia- tive randomized controlled trial, journal of the american medical association 288 (2002): 321-333; o. ylikorkala and m. metsa- heikkila, hormone replacement therapy in women with a history of breast cancer, gynecological endocrinology 16 (2002): 469-478. -8. c. j. rosen, postmenopausal osteoporosis, new england journal of medicine 353 (2005): 595-603; j. f. whitfield, how to grow bone to treat osteoporosis and mend fractures, current rheumatology reports 5 (2003): 45-56. -9. r. p. heaney and r. r. recker, combination and sequential therapy of osteoporosis, new england journal of medicine 353 (2005): 624- 625; s. l. greenspan, n. m. resnick, and r. a. parker, combination therapy with hor- mone replacement and alendronate for prevention of bone loss in elderly women: a randomized controlled trial, journal of the american medical association 289 (2003): 2525-2533. -10. c. atkinson and coauthors, the effects of phytoestrogen isoflavones on bone density in women: a double-blind, randomized, placebo-controlled trial, american journal of clinical nutrition 79 (2004): 326-333; r. brynin, soy and its isoflavones: a review of their effects on bone density, alternative medicine review 7 (2002): 317-327. -11. b. h. arjmandi and coauthors, soy protein has a greater effect on bone in postmenopausal women not on hormone replacement therapy, as evidenced by reduc- ing bone resorption and urinary calcium excretion, journal of clinical endocrinology and metabolism 88 (2003): 1048-1054; t. uesugi, y. fukui, and y. yamori, beneficial effects of soybean isoflavone supplementa- tion on bone metabolism and serum lipids in postmenopausal japanese women: a four- week study, journal of the american college of nutrition 21 (2002): 97-102. -12. k. wigertz and coauthors, racial differences in calcium retention in response to dietary salt in adolescent girls, american journal of clinical nutrition 81 (2005): 845-850. -13. j. a. cauley and coauthors, longitudinal study of changes in hip bone mineral den- sity in caucasian and african-american women, journal of the american geriatrics society 53 (2005): 183-189; j. a. cauley and coauthors, bone mineral density and the risk of incident nonspinal fractures in black and white women, journal of the american medical association 293 (2005): 2102-2108. -14. a. j. lanou, s. e. berkow, and n. d. barnard, calcium, dairy products, and bone health in children and young adults: a reevaluation of the evidence, pediatrics 115 (2005): 736-743. -15. f. r. greer, bone health: it s more than calcium intake, pediatrics 115 (2005): 792-794. -16. american college of sports medicine posi- tion stand, physical activity and bone health, medicine and science in sports and exercise 36 (2004): 1985-1996. -17. j. m. welch and c. m. weaver, calcium and exercise affect the growing skeleton, nutri- tion reviews 63 (2005): 361-373; t. lloyd and coauthors, lifestyle factors and the development of bone mass and bone strength in young women, journal of pedi- atrics 144 (2004): 776-782; m. c. wang and coauthors, diet in midpuberty and seden- tary activity in prepuberty predict peak bone mass, american journal of clinical nutrition 77 (2003): 495-503; s. j. stear and coauthors, effect of a calcium and exercise intervention on the bone mineral status of 16-18-y-old adolescent girls, american jour- nal of clinical nutrition 77 (2003): 985-992. -18. e. c. cussler and coauthors, weight lifted in strength training predicts bone change in postmenopausal women, medicine and science in sports and exercise 35 (2003): 10-17. -19. m. cifuentes and coauthors, weight loss and calcium intake influence calcium ab- sorption in overweight postmenopausal women, american journal of clinical nutrition 80 (2004): 123-130; t. l. radak, caloric restriction and calcium s effect on bone metabolism and body composition in over- weight and obese premenopausal women, nutrition reviews 62 (2004): 468-481. -20. p. gerdhem and k. j. obrant, effects of cigarette-smoking on bone mass as assessed by dual-energy x-ray absorptiometry and ultrasound, osteoporosis international 13 (2002): 932-936. -21. c. oncken and coauthors, effects of smoking cessation or reduction on hormone profiles and bone turnover in postmenopausal women, nicotine and tobacco research 4 (2002): 451-458. -22. r. e. black and coauthors, children who avoid drinking cow milk have low dietary calcium intakes and poor bone health, american journal of clinical nutrition 76 (2002): 675-680. -23. h. j. kalkwarf, j. c. khoury, and b. p. lan- phear, milk intake during childhood and adolescence, adult bone density, and osteo- porotic fractures in us women, american journal of clinical nutrition 77 (2003): 257-265. -24. j. w. nieves, osteoporosis: the role of micronutrients, american journal of clinical nutrition 81 (2005): 1232s-1239s. -25. j. bell, elderly women need dietary protein to maintain bone mass, nutrition reviews 60 (2002): 337-341; b. dawson-hughes and s. s. harris, calcium intake influences the association of protein intake with rates of bone loss in elderly men and women, ameri- can journal of clinical nutrition 75 (2002): 773-779; j. h. e. promislow and coauthors, protein consumption and bone mineral density in the elderly: the rancho bernardo study, american journal of epidemiology 155 (2002): 636-644. -26. l. steingrimsdottir and coauthors, relation- ship between serum parathyroid hormone levels, vitamin d sufficiency, and calcium intake, journal of the american medical asso- ciation 294 (2005): 2336-2341. -27. h. a. bischoff-ferrari and coauthors, frac- ture prevention with vitamin d supplemen- tation: a meta-analysis of randomized controlled trials, journal of the american medical association 293 (2005): 2257-2264; d. feskanich, w. c. willett, and g. a. colditz, calcium, vitamin d, milk con- sumption, and hip fractures: a prospective study among postmenopausal women, 438 highlight 12 american journal of clinical nutrition 77 (2003): 504-511. -28. h. j. kalkwarf and coauthors, vitamin k, bone turnover, and bone mass in girls, american journal of clinical nutrition 80 (2004): 1075-1080; n. c. binkley and coau- thors, a high phylloquinone intake is re- quired to achieve maximal osteocalcin -carboxylation, american journal of clinical nutrition 76 (2002): 1055-1060. -29. k. michaelsson and coauthors, serum retinol levels and the risk of fractures, new england journal of medicine 348 (2003): 287- 294; d. feskanich and coauthors, vitamin a intake and hip fractures among postmenopausal women, journal of the american medical association 287 (2002): 47- 54; s. johnasson and coauthors, subclinical hypervitaminosis a causes fragile bones in rats, bone 31 (2002): 685-689. -30. l. a. weiss, e. barrett-connor, and d. von m hlen, ratio of n -6 to n -3 fatty acids and bone mineral density in older adults: the rancho bernardo study, american journal of clinical nutrition 81 (2005): 934-938. -31. h. vatanparast and coauthors, positive effects of vegetable and fruit consumption and calcium intake on bone mineral accrual in boys during growth from childhood to adolescence: the university of saskatchewan pediatric bone mineral ac- crual study, american journal of clinical nutrition 82 (2005): 700-706; c. p. mcgart- land and coauthors, fruit and vegetable consumption and bone mineral density: the northern ireland young hearts project, american journal of clinical nutrition 80 (2004): 1019-1023; l. doyle and k. d. cashman, the dash diet may have benefi- cial effects on bone health, nutrition reviews 62 (2004): 215-220; k. l. tucker and coau- thors, bone mineral density and dietary patterns in older adults: the framingham osteoporosis study, american journal of clinical nutrition 76 (2002): 245-252. -32. m. harrington and k. d. cashman, high salt intake appears to increase bone resorp- tion in postmenopausal women but high potassium intake ameliorates this adverse effect, nutrition reviews 61 (2003): 179-183; tucker and coauthors, 2002. -33. v. matkovic and coauthors, calcium supple- mentation and bone mineral density in females from childhood to young adult- hood: a randomized controlled trial, ameri- can journal of clinical nutrition 81 (2005): 175-188; r. p. dodiuk-gad and coauthors, sustained effect of short-term calcium supplementation on bone mass in adoles- cent girls with low calcium intake, american journal of clinical nutrition 81 (2005): 168- 174; l. d. mccabe and coauthors, dairy intakes affect bone density in the elderly, american journal of clinical nutrition 80 (2004): 1066-1074. -34. e. a. ross, n. j. szabo, and i. r. tebbett, lead content of calcium supplements, journal of the american medical association 284 (2000): 1425-1429. -35. nih consensus development panel on osteoporosis prevention, diagnosis, and therapy, osteoporosis prevention, diagno- sis, and therapy, journal of the american medical association 285 (2001): 785-795. this page intentionally left blank food image source/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow figure 13-3: animated! -iron recycled in the body figure 13-6: animated! -enteropancreatic circulation of zinc nutrition portfolio journal nutrition calculations: practice problems nutrition in your life trace barely a perceptible amount. -but the trace minerals tackle big jobs. -your blood can t carry oxygen without iron, and insulin can t deliver glucose without chromium. -teeth become decayed without fluoride, and thyroid glands develop goiter without iodine. -together, the trace minerals iron, zinc, iodine, selenium, copper, manganese, fluoride, chromium, and molybdenum keep you healthy and strong. -where can you get these amazing minerals? -a variety of foods, especially those from the meat and meat alternate group, sprinkled with a little iodized salt and complemented by a glass of fluoridated water will do the trick. -it s remarkable what your body can do with only a few milligrams or even micrograms of the trace minerals. -the trace minerals figure 12-9 in the last chapter (p. 409) showed the tiny quantities of trace minerals in the human body. -the trace minerals are so named because they are present, and needed, in relatively small amounts in the body. -all together, they would produce only a bit of dust, hardly enough to fill a tea- spoon. -yet they are no less important than the major minerals or any of c h a p t e r 13 chapter outline the trace minerals an overview iron iron roles in the body iron absorption and metabolism iron defi- ciency iron toxicity iron recommen- dations and sources iron contamina- tion and supplementation zinc zinc roles in the body zinc absorption and metabolism zinc deficiency zinc toxicity zinc recommendations and sources zinc supplementation the other nutrients. -each of the trace minerals performs a vital role. -a de- iodine ficiency of any of them may be fatal, and an excess of many is equally deadly. -remarkably, people s diets normally supply just enough of these minerals to maintain health. -the trace minerals an overview the body requires the trace minerals in minuscule quantities. -they participate in di- verse tasks all over the body, each having special duties that only it can perform. -food sources the trace mineral contents of foods depend on soil and water com- position and on how foods are processed. -furthermore, many factors in the diet and within the body affect the minerals bioavailability. -still, outstanding food sources for each of the trace minerals, just like those for the other nutrients, include a wide variety of foods, especially unprocessed, whole foods. -deficiencies severe deficiencies of the better-known minerals are easy to recog- nize. -deficiencies of the others may be harder to diagnose, and for all minerals, mild deficiencies are easy to overlook. -because the minerals are active in all the body sys- tems the gi tract, cardiovascular system, blood, muscles, bones, and central ner- vous system deficiencies can have wide-reaching effects and can affect people of all ages. -the most common result of a deficiency in children is failure to grow and thrive. -toxicities some of the trace minerals are toxic at intakes not far above the esti- mated requirements. -thus it is important not to habitually exceed the upper level of recommended intakes. -many vitamin-mineral supplements contain trace miner- als, making it easy for users to exceed their needs. -highlight 10 discusses supple- ment use and some of the regulations included in the dietary supplement health selenium copper manganese fluoride chromium molybdenum other trace minerals contaminant minerals closing thoughts on the nutrients highlight 13 phytochemicals and functional foods reminder: bioavailability refers to the rate at and the extent to which a nutrient is absorbed and used. -trace minerals: essential mineral nutrients found in the human body in amounts smaller than 5 g; sometimes called microminerals. -441 442 chapter 13 iron s two ionic states: ferrous iron (reduced): fe++ ferric iron (oxidized): fe+++ reminder: a cofactor is a substance that works with an enzyme to facilitate a chem- ical reaction. -and education act. -as that discussion notes, the food and drug administration (fda) has no authority to limit the amounts of trace minerals in supplements; con- sumers have demanded the freedom to choose their own doses of nutrients. -* individ- uals who take supplements must therefore be aware of the possible dangers and select supplements that contain no more than 100 percent of the daily value. -it would be easier and safer to meet nutrient needs by selecting a variety of foods than by combining an assortment of supplements (see highlight 10). -interactions interactions among the trace minerals are common and often well coordinated to meet the body s needs. -for example, several of the trace minerals support insulin s work, influencing its synthesis, storage, release, and action. -at other times, interactions lead to nutrient imbalances. -an excess of one may cause a deficiency of another. -(a slight manganese overload, for example, may ag- gravate an iron deficiency.) -a deficiency of one may interfere with the work of an- other. -(a selenium deficiency halts the activation of the iodine-containing thyroid hormones.) -a deficiency of a trace mineral may even open the way for a contami- nant mineral to cause a toxic reaction. -(iron deficiency, for example, makes the body vulnerable to lead poisoning.) -these examples reinforce the need to balance intakes and to use supplements wisely, if at all. -a good food source of one nutrient may be a poor food source of another, and factors that enhance the action of some trace minerals may interfere with others. -(meats are a good source of iron but a poor source of calcium; vitamin c enhances the absorption of iron but hinders that of copper.) -research on the trace minerals is active, suggesting that we have much more to learn about them. -in summary although the body uses only tiny amounts of the trace minerals, they are vi- tal to health. -because so little is required, the trace minerals can be toxic at levels not far above estimated requirements a consideration for supplement users. -like the other nutrients, the trace minerals are best obtained by eating a variety of whole foods. -iron iron is an essential nutrient, vital to many of the cells activities, but it poses a prob- lem for millions of people. -some people simply don t eat enough iron-containing foods to support their health optimally, whereas others absorb so much iron that it threatens their health. -iron exemplifies the principle that both too little and too much of a nutrient in the body can be harmful. -in its wisdom, the body has several ways to achieve iron homeostasis, protecting against both deficiency and overload.1 iron roles in the body iron has the knack of switching back and forth between two ionic states. -in the re- duced state, iron has lost two electrons and therefore has a net positive charge of two; it is known as ferrous iron. -in the oxidized state, iron has lost a third electron, has a net positive charge of three, and is known as ferric iron. -ferrous iron can be oxidized to ferric iron, and ferric iron can be reduced to ferrous iron. -thus iron can serve as a cofactor to enzymes involved in oxidation-reduction reactions reactions so wide- spread in metabolism that they occur in all cells. -enzymes involved in making amino acids, collagen, hormones, and neurotransmitters all require iron. -(for de- tails about ions, oxidation, and reduction, see appendix b.) -* canada regulates the amounts of trace minerals in supplements. -iron forms a part of the electron carriers that participate in the electron trans- port chain (discussed in chapter 7). -* in this pathway, these carriers transfer hydro- gens and electrons to oxygen, forming water, and in the process, make atp for the cells energy use. -most of the body s iron is found in two proteins: hemoglobin in the red blood cells and myoglobin in the muscle cells. -in both, iron helps accept, carry, and then release oxygen. -iron absorption and metabolism the body conserves iron. -because it is difficult to excrete iron once it is in the body, balance is maintained primarily through absorption. -more iron is absorbed when stores are empty and less is absorbed when stores are full.2 iron absorption special proteins help the body absorb iron from food (see figure 13-1). -one protein, called mucosal ferritin, receives iron from food and stores it in the mucosal cells of the small intestine. -when the body needs iron, mucosal fer- ritin releases some iron to another protein, called mucosal transferrin. -mucosal transferrin transfers the iron to another protein, blood transferrin, which transports the iron to the rest of the body. -if the body does not need iron, it is carried out when the intestinal cells are shed and excreted in the feces; intestinal cells are replaced about every three to five days. -by holding iron temporarily, these cells control iron absorption by either delivering iron when the day s intake falls short or disposing of it when intakes exceed needs. -heme and nonheme iron iron absorption depends in part on its dietary source.3 iron occurs in two forms in foods: as heme iron, which is found only in foods derived from the flesh of animals, such as meats, poultry, and fish and as non- heme iron, which is found in both plant-derived and animal-derived foods (see fig- ure 13-2, p. 444). -on average, heme iron represents about 10 percent of the iron a * the iron-containing electron carriers of the electron transport chain are known as cytochromes. -see appendix c for details of this pathway. -the trace minerals 443 reminder: hemoglobin is the oxygen-carrying protein of the red blood cells that trans- ports oxygen from the lungs to tissues throughout the body; hemoglobin accounts for 80% of the body s iron. -a mucous membrane such as the one that lines the gi tract is sometimes called the mucosa (mu-ko-sa). -the adjective of mucosa is mucosal (mu-ko-sal). -myoglobin: the oxygen-holding protein of the muscle cells. -myo = muscle ferritin (fair-ih-tin): the iron storage protein. -transferrin (trans-fair-in): the iron transport protein. -heme (heem): the iron-holding part of the hemoglobin and myoglobin proteins. -about 40% of the iron in meat, fish, and poultry is bound into heme; the other 60% is nonheme iron. -figure 13-1 iron absorption iron in food if the body does not need iron iron is not absorbed and is excreted in shed intestinal cells instead. -thus, iron absorption is reduced when the body does not need iron. -mucosal cells in the intestine store excess iron in mucosal ferritin (a storage protein). -if the body needs iron mucosal ferritin releases iron to mucosal transferrin (a transport protein), which hands off iron to another transferrin that travels through the blood to the rest of the body. -444 chapter 13 figure 13-2 heme and nonheme iron in foods only foods derived from animal flesh provide heme, but they also contain nonheme iron. -key: heme nonheme all of the iron in foods derived from plants is nonheme iron. -heme accounts for about 10% of the average daily iron intake, but it is well absorbed (about 25%). -nonheme iron accounts for the remaining 90%, but it is less well absorbed (about 17%). -s e g a m i y t t e g / s e r u t c i p x d n a r b / . -r j k n i f . -f n i m a j n e b person consumes in a day. -even though heme iron accounts for only a small propor- tion of the intake, it is so well absorbed that it contributes significant iron. -about 25 percent of heme iron and 17 percent of nonheme iron is absorbed, depending on di- etary factors and the body s iron stores.4 in iron deficiency, absorption increases. -in iron overload, absorption declines.5 researchers disagree as to whether heme iron absorption responds to iron stores as sensitively as nonheme iron absorption does. -absorption-enhancing factors meat, fish, and poultry contain not only the well-absorbed heme iron, but also a peptide (called the mfp factor) that promotes the absorption of nonheme iron from other foods eaten at the same meal.6 vita- min c also enhances nonheme iron absorption from foods eaten in the same meal by capturing the iron and keeping it in the reduced ferrous form, ready for absorp- tion. -some acids and sugars also enhance nonheme iron absorption. -absorption-inhibiting factors some dietary factors bind with nonheme iron, in- hibiting absorption. -these factors include the phytates in legumes, whole grains, and rice; the vegetable proteins in soybeans, other legumes, and nuts; the calcium in milk; and the polyphenols (such as tannic acid) in tea, coffee, grain products, oregano, and red wine. -dietary factors combined the many dietary enhancers, inhibitors, and their combined effects make it difficult to estimate iron absorption. -most of these factors exert a strong influence individually, but not when combined with the others in a meal. -furthermore, the impact of the combined effects diminishes when a diet is evaluated over several days. -when multiple meals are analyzed together, three fac- tors appear to be most relevant: mfp and vitamin c as enhancers and phytates as inhibitors. -individual variation overall, about 18 percent of dietary iron is absorbed from mixed diets and only about 10 percent from vegetarian diets.7 as you might expect, vegetarian diets do not have the benefit of easy-to-absorb heme iron or the help of mfp in enhancing absorption. -in addition to dietary influences, iron absorption also depends on an individual s health, stage in the life cycle, and iron status. -absorption can be as low as 2 percent in a person with gi disease or as high as 35 percent in a rapidly growing, healthy child. -the body adapts to absorb more iron when a per- son s iron stores fall short or when the need increases for any reason (such as preg- nancy). -the body makes more mucosal transferrin to absorb more iron from the intestines and more blood transferrin to carry more iron around the body. -similarly, when iron stores are sufficient, the body adapts to absorb less iron. -iron transport and storage blood transferrin delivers iron to the bone marrow and other tissues. -the bone marrow uses large quantities to make new red blood this chili dinner provides several factors that may enhance iron absorption: heme and non- heme iron and mfp from meat, nonheme iron from legumes, and vitamin c from tomatoes. -factors that enhance nonheme iron absorption: mfp factor vitamin c (ascorbic acid) factors that inhibit nonheme iron absorption: phytates (legumes, grains, and rice) vegetable proteins (soybeans, legumes, nuts) calcium (milk) tannic acid (and other polyphenols in tea and coffee) mfp factor: a peptide released during the digestion of meat, fish, and poultry that enhances nonheme iron absorption. -the trace minerals 445 cells, whereas other tissues use less. -surplus iron is stored in the protein ferritin, pri- marily in the liver, but also in the bone marrow and spleen. -when dietary iron has been plentiful, ferritin is constantly and rapidly made and broken down, providing an ever-ready supply of iron. -when iron concentrations become abnormally high, the liver converts some ferritin into another storage protein called hemosiderin. -hemosiderin releases iron more slowly than ferritin does. -by storing excess iron, the body protects itself: free iron acts as a free radical, attacking cell lipids, dna, and protein. -(see highlight 11 for more information on free radicals and the damage they can cause.) -iron recycling the average red blood cell lives about four months; then the spleen and liver cells remove it from the blood, take it apart, and prepare the degra- dation products for excretion or recycling. -the iron is salvaged: the liver attaches it to blood transferrin, which transports it back to the bone marrow to be reused in making new red blood cells. -thus, although red blood cells live for only about four months, the iron recycles through each new generation of cells (see figure 13-3). -the body loses some iron daily via the gi tract and, if bleeding occurs, in blood. -only tiny amounts of iron are lost in urine, sweat, and shed skin. -* iron balance maintaining iron balance depends on the careful regulation of iron absorption, transport, storage, recycling, and losses. -the hormone hepcidin is cen- tral to the regulation of iron balance.8 produced by the liver, hepcidin helps to main- tain blood iron within the normal range by inhibiting absorption from the intestines and transport out of storage as needed. -iron deficiency worldwide, iron deficiency is the most common nutrient deficiency, affecting more than 1.2 billion people.9 in developing countries, almost half of preschool chil- * adults lose about 1.0 milligram of iron per day. -women lose additional iron in menses. -menstrual losses vary considerably, but over a month, they average about 0.5 milligram per day. -hemosiderin (heem-oh-sid-er-in): an iron- storage protein primarily made in times of iron overload. -hepcidin: a hormone produced by the liver that regulates iron balance. -iron deficiency: the state of having depleted iron stores. -figure 13-3 animated! -iron recycled in the body once iron enters the body, most of it is recycled. -some is lost with body tissues and must be replaced by eating iron-containing food. -some losses via sweat, skin, and urine transferrin carries iron in blood. -liver (and spleen) dismantles red blood cells, packages iron into transferrin, and stores excess iron in ferritin (and hemosiderin). -some iron delivered to myoglobin of muscle cells bone marrow incorporates iron into hemoglobin of red blood cells and stores excess iron in ferritin (and hemosiderin). -some losses if bleeding occurs iron-containing hemoglobin in red blood cells carries oxygen. -to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow 446 chapter 13 high risk for iron deficiency: women in their reproductive years pregnant women infants and young children teenagers the iron content of blood is about 0.5 mg/100 ml blood. -a person donating a pint of blood (approximately 500 ml) loses about 2.5 mg of iron. -stages of iron deficiency: iron stores diminish transport iron decreases hemoglobin production declines iron-deficiency anemia is a microcytic (my-cro-sit-ic) hypochromic (high- po-krome-ic) anemia. -micro = small cytic = cell hypo = too little chrom = color iron-deficiency anemia: severe depletion of iron stores that results in low hemoglobin and small, pale red blood cells. -anemias that impair hemoglobin synthesis are microcytic (small cell). -micro = small cytic = cell erythrocyte protoporphyrin (pro-toe- pore-fe-rin): a precursor to hemoglobin. -hematocrit (hee-mat-oh-krit): measurement of the volume of the red blood cells packed by centrifuge in a given volume of blood. -dren and pregnant women suffer from iron-deficiency anemia.10 in the united states, iron deficiency is less prevalent, but it still affects 10 percent of tod- dlers, adolescent girls, and women of childbearing age. -iron deficiency is also rel- atively common among overweight children and adolescents compared with those who are normal weight.11 preventing and correcting iron deficiency are high priorities.12 vulnerable stages of life some stages of life demand more iron but provide less, making deficiency likely. -women in their reproductive years are especially prone to iron deficiency because of repeated blood losses during menstruation. -pregnancy demands additional iron to support the added blood volume, growth of the fetus, and blood loss during childbirth. -infants and young children receive lit- tle iron from their high-milk diets, yet need extra iron to support their rapid growth. -iron deficiency among toddlers in the united states is common.13 the rapid growth of adolescence, especially for males, and the menstrual losses of females also demand extra iron that a typical teen diet may not provide. -an adequate iron intake is especially important during these stages of life. -blood losses bleeding from any site incurs iron losses. -in some cases, such as an active ulcer, the bleeding may not be obvious, but even small chronic blood losses sig- nificantly deplete iron reserves. -in developing countries, blood loss is often brought on by malaria and parasitic infections of the gi tract. -people who donate blood reg- ularly also incur losses and may benefit from iron supplements. -as mentioned, men- strual losses can be considerable as they tap women s iron stores regularly. -assessment of iron deficiency iron deficiency develops in stages. -this section provides a brief overview of how to detect these stages, and appendix e provides more details. -in the first stage of iron deficiency, iron stores diminish. -measures of serum ferritin (in the blood) reflect iron stores and are most valuable in assessing iron status at this earliest stage. -the second stage of iron deficiency is characterized by a decrease in transport iron: serum iron falls, and the iron-carrying protein transferrin increases (an adap- tation that enhances iron absorption). -together, measurements of serum iron and transferrin can determine the severity of the deficiency the more transferrin and the less iron in the blood, the more advanced the deficiency is. -transferrin satura- tion the percentage of transferrin that is saturated with iron decreases as iron stores decline. -the third stage of iron deficiency occurs when the lack of iron limits hemoglobin production. -now the hemoglobin precursor, erythrocyte protoporphyrin, be- gins to accumulate as hemoglobin and hematocrit values decline. -hemoglobin and hematocrit tests are easy, quick, and inexpensive, so they are the tests most commonly used in evaluating iron status. -their usefulness in detect- ing iron deficiency is limited, however, because they are late indicators. -further- more, other nutrient deficiencies and medical conditions can influence their values. -iron deficiency and anemia iron deficiency and iron-deficiency anemia are not the same: people may be iron deficient without being anemic. -the term iron defi- ciency refers to depleted body iron stores without regard to the degree of depletion or to the presence of anemia. -the term iron-deficiency anemia refers to the severe deple- tion of iron stores that results in a low hemoglobin concentration. -in iron-deficiency anemia, hemoglobin synthesis decreases, resulting in red blood cells that are pale (hypochronic) and small (microcytic), as shown in figure 13-4.14 these cells can t carry enough oxygen from the lungs to the tissues. -without adequate iron, energy metabolism in the cells falters. -the result is fatigue, weakness, headaches, apathy, pallor, and poor resistance to cold temperatures. -because hemoglobin is the bright red pigment of the blood, the skin of a fair person who is anemic may become no- ticeably pale. -in a dark-skinned person, the tongue and eye lining, normally pink, is very pale. -figure 13-4 normal and anemic blood cells ) h t o b ( the trace minerals 447 d e t i m i l n u s l a u s i v / s i l l i w n e d d a l g . -r d both size and color are normal in these blood cells. -blood cells in iron-deficiency anemia are small (microcytic) and pale (hypochromic) because they contain less hemoglobin. -the fatigue that accompanies iron-deficiency anemia differs from the tiredness a person experiences from a simple lack of sleep. -people with anemia feel fatigue only when they exert themselves. -iron supplementation can relieve the fatigue and improve the body s response to physical activity.15 (the iron needs of physically ac- tive people and the special iron deficiency known as sports anemia are discussed in chapter 14.) -iron deficiency and behavior long before the red blood cells are affected and anemia is diagnosed, a developing iron deficiency affects behavior. -even at slightly lowered iron levels, energy metabolism is impaired and neurotransmitter synthesis is altered, reducing physical work capacity and mental productivity.16 without the physical energy and mental alertness to work, plan, think, play, sing, or learn, peo- ple simply do these things less. -they have no obvious deficiency symptoms; they just appear unmotivated, apathetic, and less physically fit. -work productivity and vol- untary activities decline. -many of the symptoms associated with iron deficiency are easily mistaken for behavioral or motivational problems. -a restless child who fails to pay attention in class might be thought contrary. -an apathetic homemaker who has let housework pile up might be thought lazy. -no responsible dietitian would ever claim that all behavioral problems are caused by nutrient deficiencies, but poor nutrition is al- ways a possible contributor to problems like these. -when investigating a behav- ioral problem, check the adequacy of the diet and seek a routine physical examination before undertaking more expensive, and possibly harmful, treatment options. -(the effects of iron deficiency on children s behavior are discussed further in chapter 16.) -iron deficiency and pica a curious behavior seen in some iron-deficient people, especially in women and children of low-income groups, is pica an appetite for ice, clay, paste, and other nonfood substances. -these substances contain no iron and cannot remedy a deficiency; in fact, clay actually inhibits iron absorption, which may explain the iron deficiency that accompanies such behavior. -iron toxicity in general, even a diet that includes fortified foods poses no special risk for iron tox- icity.17 the body normally absorbs less iron when its stores are full, but some individ- uals are poorly defended against excess iron. -once considered rare, iron overload has emerged as an important disorder of iron metabolism and regulation. -pica (pie-ka): a craving for nonfood substances. -also known as geophagia (gee- oh-fay-gee-uh) when referring to clay eating and pagophagia (pag-oh-fay-gee-uh) when referring to ice craving. -iron overload: toxicity from excess iron. -448 chapter 13 hemochromatosis (he-moh-kro-ma-toe- sis): a genetically determined failure to prevent absorption of unneeded dietary iron that is characterized by iron overload and tissue damage. -hemosiderosis (he-moh-sid-er-oh-sis): a condition characterized by the deposition of hemosiderin in the liver and other tissues. -iron overload the iron overload disorder known as hemochromatosis is usu- ally caused by a genetic failure to prevent unneeded iron in the diet from being absorbed.18 recent research suggests that just as insulin supports normal glucose homeostasis and its absence or ineffectiveness causes diabetes, the hormone hep- cidin supports iron homeostasis and its absence or ineffectiveness causes he- mochromatosis. -hereditary hemochromatosis is the most common genetic disorder in the united states, affecting some 1.5 million people. -other causes of iron overload include re- peated blood transfusions (which bypass the intestinal defense), massive doses of supplementary iron (which overwhelm the intestinal defense), and other rare metabolic disorders. -excess iron may cause hemosiderosis, a condition character- ized by deposits of the iron storage protein hemosiderin in the liver, heart, joints, and other tissues. -some of the signs and symptoms of iron overload are similar to those of iron de- ficiency: apathy, lethargy, and fatigue. -therefore, taking iron supplements before assessing iron status is clearly unwise; hemoglobin tests alone would fail to make the distinction because excess iron accumulates in storage. -iron overload assess- ment tests measure transferrin saturation and serum ferritin. -iron overload is characterized by tissue damage, especially in iron-storing or- gans such as the liver. -infections are likely because bacteria thrive on iron-rich blood. -symptoms are most severe in alcohol abusers because alcohol damages the intestine, further impairing its defenses against absorbing excess iron. -untreated hemochromatosis increases the risks of diabetes, liver cancer, heart disease, and arthritis. -iron overload is more common in men than in women and is twice as prevalent among men as iron deficiency. -the widespread fortification of foods with iron makes it difficult for people with hemochromatosis to follow a low-iron diet, and greater dangers lie in the indiscriminate use of iron and vitamin c supplements. -vi- tamin c not only enhances iron absorption, but also releases iron from ferritin, al- lowing free iron to wreak the damage typical of free radicals. -thus vitamin c acts as a prooxidant when taken in high doses. -(see highlight 11 for a discussion of free radicals and their effects on disease development.) -iron and heart disease some research suggests a link between heart disease and iron, especially when accompanied by alcohol consumption.19 as mentioned, free radicals can attack ferritin, causing it to release iron from storage. -free iron, in turn, acts as an oxidant that can generate more free radicals. -whether iron s role in oxidative stress contributes to the development of diseases is unclear.20 iron and cancer there may be an association between iron and some cancers.21 explanations for how iron might be involved in causing cancer focus on its free- radical activity, which can damage dna (see highlight 11). -one of the benefits of a high-fiber diet may be that the accompanying phytates bind iron, making it less available for such reactions. -iron poisoning large doses of iron supplements cause gi distress, including con- stipation, nausea, vomiting, and diarrhea. -these effects may not be as serious as other consequences of iron toxicity, but they are consistent enough to establish an upper level of 45 milligrams per day for adults. -ingestion of iron-containing supplements remains a leading cause of accidental poisoning in small children. -symptoms of toxicity include nausea, vomiting, diar- rhea, a rapid heartbeat, a weak pulse, dizziness, shock, and confusion. -as few as five iron tablets containing as little as 200 milligrams of iron have caused the deaths of dozens of young children. -the exact cause of these deaths is uncertain, but excessive free-radical damage is thought to play a role in heart failure and res- piratory distress. -autopsy reports reveal iron deposits and cell death in the stom- ach, small intestine, liver, and blood vessels (which can cause internal bleeding). -keep iron-containing tablets out of the reach of children. -if you suspect iron poison- ing, call the nearest poison control center or a physician immediately. -the trace minerals 449 to calculate the rda for vegetarians, multi- ply by 1.8: 8 mg (cid:4) 1.8 = 14 mg/day (vegetarian men) 18 mg (cid:4) 1.8 = 32 mg/day (vegetarian women, 19 to 50 yr) iron recommendations and sources to obtain enough iron, people must first select iron-rich foods and then take advan- tage of factors that maximize iron absorption. -this discussion begins by identifying iron-rich foods and then reviews the factors affecting absorption. -recommended iron intakes the usual diet in the united states provides about 6 to 7 milligrams of iron for every 1000 kcalories. -the recommended daily intake for men is 8 milligrams, and because most men eat more than 2000 kcalories a day, they can meet their iron needs with little effort. -women in their reproductive years, however, need 18 milligrams a day. -the accompanying how to explains how to calculate the recommended intake. -vegetarians need 1.8 times as much iron to make up for the low bioavailabil- ity typical of their diets.22 to maximize iron absorption, vegetarians should incor- porate iron-rich foods into a diet that is low in inhibitors (foods such as leavened breads and fermented soy products such as miso and tempeh) and high in en- hancers (foods rich in vitamin c and the organic acids found in fruits and vegeta- bles). -good vegetarian sources of iron include soy foods (such as soybeans and tofu), legumes (such as lentils and kidney beans), nuts (such as cashews and al- monds), seeds (such as pumpkin seeds and sunflower seeds), cereals (such as cream of wheat and oatmeal), dried fruit (such as apricots and raisins), vegetables (such as mushrooms and potatoes), and blackstrap molasses. -because women have higher iron needs and lower energy needs, they sometimes have trouble obtaining enough iron. -on average, women receive only 12 to 13 mil- ligrams of iron per day, which is not enough iron for women until after menopause. -to meet their iron needs from foods, premenopausal women need to select iron-rich foods at every meal. -dietary guidelines for americans 2005 women of childbearing age who may become pregnant should eat foods high in heme-iron and/or consume iron-rich plant foods or iron-fortified foods with an enhancer of iron absorption, such as vitamin c-rich foods. -iron in foods figure 13-5 (p. 450) shows the amounts of iron in selected foods. -meats, fish, and poultry contribute the most iron per serving; other protein-rich foods such as legumes and eggs are also good sources. -although an indispensable part of the diet, foods in the milk group are notoriously poor in iron. -grain products vary, with whole-grain, enriched, and fortified breads and cereals contributing sig- nificantly to iron intakes. -finally, dark greens (such as broccoli) and dried fruits (such as raisins) contribute some iron. -e r o o m . -m g i a r c when the label on a grain product says enriched, it means iron and several b vita- mins have been added. -how to estimate the recommended daily intake for iron to calculate the recommended daily iron intake, the dri committee considers a number of factors. -for example, for a woman of childbearing age (19 to 50): losses from feces, urine, sweat, and shed skin: 1.0 milligram losses through menstruation: 0.5 mil- ligram (about 14 milligrams total aver- aged over 28 days) these losses reflect an average daily need (total) of 1.5 milligrams of absorbed iron. -an estimated average requirement is determined based on the daily need and the assumption that an average of 18 percent of ingested iron is absorbed: 1.5 mg iron (needed) (cid:2) 0.18 (percent iron absorbed) (cid:3) 8 mg iron (estimated average requirement) then, a margin of safety is added to cover the needs of essentially all women of childbearing age, and the rda is set at 18 milligrams. -450 chapter 13 figure 13-5 iron in selected foods see the how to section on p. 329 for more information on using this figure. -food serving size (kcalories) 0 2 4 6 8 10 12 14 16 18 milligrams c (31 kcal) c fresh (22 kcal) bread, whole wheat cornflakes, fortified spaghetti pasta tortilla, flour broccoli carrots 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 c cooked (99 kcal) 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 1 2 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) potato tomato juice banana orange strawberries watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg 1 hard cooked (78 kcal) excellent, and sometimes unusual, sources: clams, canned beef liver parsley 3 oz (126 kcal) 3 oz fried (184 kcal) 1 c raw (22 kcal) c low-fat 2% (101 kcal) c cooked (117 kcal) c (76 kcal) rda for women 19 50 rda for women 51+ rda for men iron meats (red), legumes (brown), and some vegetables (green) make the greatest contributions of iron to the diet. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie iron-enriched foods iron is one of the enrichment nutrients for grain products. -one serving of enriched bread or cereal provides only a little iron, but because peo- ple eat many servings of these foods, the contribution can be significant. -iron added to foods is not absorbed as well as naturally occurring iron, but when eaten with ab- sorption-enhancing foods, enrichment iron can make a difference. -in cases of iron overload, enrichment may exacerbate the problem.23 maximizing iron absorption in general, the bioavailability of iron is high in meats, fish, and poultry, intermediate in grains and legumes, and low in most veg- etables, especially those containing oxalates such as spinach. -as mentioned earlier, the amount of iron ultimately absorbed from a meal depends on the combined ef- fects of several enhancing and inhibiting factors. -for maximum absorption of non- heme iron, eat meat for mfp and fruits or vegetables for vitamin c. the iron of baked beans, for example, will be enhanced by the mfp in a piece of ham served with them. -the iron of bread will be enhanced by the vitamin c in a slice of tomato on a sandwich. -contamination iron: iron found in foods as the result of contamination by inorganic iron salts from iron cookware, iron-containing soils, and the like. -iron contamination and supplementation in addition to the iron from foods, contamination iron from nonfood sources of inorganic iron salts can contribute to the day s intakes. -people can also get iron from supplements. -contamination iron foods cooked in iron cookware take up iron salts. -the more acidic the food and the longer it is cooked in iron cookware, the higher the iron content. -the iron content of eggs can triple in the time it takes to scramble them in an iron pan. -admittedly, the absorption of this iron may be poor (perhaps only 1 to 2 percent), but every little bit helps a person who is trying to increase iron intake. -iron supplements people who are iron deficient may need supplements as well as an iron-rich, absorption-enhancing diet. -many physicians routinely recommend iron supplements to pregnant women, infants, and young children. -iron from sup- plements is less well absorbed than that from food, so the doses must be high. -the absorption of iron taken as ferrous sulfate or as an iron chelate is better than that from other iron supplements. -absorption also improves when supplements are taken between meals, at bedtime on an empty stomach, and with liquids (other than milk, tea, or coffee, which inhibit absorption). -taking iron supplements in a single dose instead of several doses per day is equally effective and may improve a person s willingness to take it regularly. -there is no benefit to taking iron supplements with orange juice because vita- min c does not enhance absorption from supplements as it does from foods. -(vita- min c enhances iron absorption by converting insoluble ferric iron in foods to the more soluble ferrous iron, and supplemental iron is already in the ferrous form.) -constipation is a common side effect of iron supplementation; drinking plenty of water may help to relieve this problem. -in summary most of the body s iron is in hemoglobin and myoglobin where it carries oxy- gen for use in energy metabolism; some iron is also required for enzymes in- volved in a variety of reactions. -special proteins assist with iron absorption, transport, and storage all helping to maintain an appropriate balance, be- cause both too little and too much iron can be damaging. -iron deficiency is most common among infants and young children, teenagers, women of child- bearing age, and pregnant women. -symptoms include fatigue and anemia. -iron overload is most common in men. -heme iron, which is found only in meat, fish, and poultry, is better absorbed than nonheme iron, which occurs in most foods. -nonheme iron absorption is improved by eating iron-containing foods with foods containing the mfp factor and vitamin c; absorption is lim- ited by phytates and oxalates. -the summary table presents a few iron facts. -iron rda men: 8 mg/day women: 18 mg/day (19 50 yr) 8 mg/day (51(cid:5)) upper level adults: 45 mg/day chief functions in the body part of the protein hemoglobin, which carries oxygen in the blood; part of the protein myo- globin in muscles, which makes oxygen avail- able for muscle contraction; necessary for the utilization of energy as part of the cells meta- bolic machinery significant sources red meats, fish, poultry, shellfish, eggs, legumes, dried fruits deficiency symptoms anemia: weakness, fatigue, headaches; im- paired work performance and cognitive func- tion; impaired immunity; pale skin, nailbeds, mucous membranes, and palm creases; con- cave nails; inability to regulate body tempera- ture; pica toxicity symptoms gi distress iron overload: infections, fatigue, joint pain, skin pigmentation, organ damage the trace minerals 451 . -c n i s o i d u t s a r a l o p an old-fashioned iron skillet adds iron to foods. -chelate (key-late): a substance that can grasp the positive ions of a mineral. -chele = claw 452 chapter 13 reminder: a cofactor is a substance that works with an enzyme to facilitate a chem- ical reaction. -zinc zinc is a versatile trace element required as a cofactor by more than 100 enzymes. -virtually all cells contain zinc, but the highest concentrations are found in muscle and bone.24 metalloenzymes that require zinc: help make parts of the genetic materials dna and rna manufacture heme for hemoglobin participate in essential fatty acid metabolism release vitamin a from liver stores metabolize carbohydrates synthesize proteins metabolize alcohol in the liver dispose of damaging free radicals metalloenzymes (meh-tal-oh-en-zimes): enzymes that contain one or more minerals as part of their structures. -metallothionein (meh-tal-oh-thigh-oh- neen): a sulfur-rich protein that avidly binds with and transports metals such as zinc. -metallo = containing a metal thio = containing sulfur ein = a protein enteropancreatic (en-ter-oh-pan-kree-at- ik) circulation: the circulatory route from the pancreas to the intestine and back to the pancreas. -zinc roles in the body zinc supports the work of numerous proteins in the body, such as the metalloen- zymes, which are involved in a variety of metabolic processes, including the reg- ulation of gene expression. -* in addition, zinc stabilizes cell membranes, helping to strengthen their defense against free-radical attacks. -zinc also assists in immune function and in growth and development. -zinc participates in the synthesis, storage, and release of the hormone insulin in the pancreas, although it does not appear to play a direct role in insulin s action. -zinc interacts with platelets in blood clotting, affects thyroid hormone function, and influences behavior and learning perfor- mance. -it is needed to produce the active form of vitamin a (retinal) in visual pig- ments and the retinol-binding protein that transports vitamin a. it is essential to normal taste perception, wound healing, the making of sperm, and fetal develop- ment. -a zinc deficiency impairs all these and other functions, underlining the vast importance of zinc in supporting the body s proteins. -zinc absorption and metabolism the body s handling of zinc resembles that of iron in some ways and differs in oth- ers. -a key difference is the circular passage of zinc from the intestine to the body and back again. -zinc absorption the rate of zinc absorption varies from about 15 to 40 percent, depending on a person s zinc status if more is needed, more is absorbed. -also, di- etary factors influence zinc absorption. -for example, phytates bind zinc, thus limit- ing its bioavailability.25 upon absorption into an intestinal cell, zinc has two options. -it may become in- volved in the metabolic functions of the cell itself. -alternatively, it may be retained within the cell by metallothionein, a special binding protein similar to the iron storage protein, mucosal ferritin. -metallothionein in the intestinal cells helps to regulate zinc absorption by hold- ing it in reserve until the body needs zinc. -then metallothionein releases zinc into the blood where it can be transported around the body. -metallothionein in the liver performs a similar role, binding zinc until other body tissues signal a need for it. -zinc recycling some zinc eventually reaches the pancreas, where it is incorpo- rated into many of the digestive enzymes that the pancreas releases into the intes- tine at mealtimes. -the intestine thus receives two doses of zinc with each meal one from foods and the other from the zinc-rich pancreatic secretions. -the recycling of zinc in the body from the pancreas to the intestine and back to the pancreas is re- ferred to as the enteropancreatic circulation of zinc. -as this zinc circulates through the intestine, it may be excreted in shed intestinal cells or absorbed into the body on any of its times around (see figure 13-6). -the body loses zinc primarily in feces. -smaller losses occur in urine, shed skin, hair, sweat, menstrual fluids, and se- men. -zinc transport zinc s main transport vehicle in the blood is the protein albumin. -some zinc also binds to transferrin the same transferrin that carries iron in the * among the metalloenzymes requiring zinc are carbonic anhydrase, deoxythymidine kinase, dna and rna polymerase, and alkaline phosphatase. -figure 13-6 animated! -enteropancreatic circulation of zinc some zinc from food is absorbed by the small intestine and sent to the pancreas to be incorporated into digestive enzymes that return to the small intestine. -this cycle is called the enteropancreatic circulation of zinc. -to test your understanding of these concepts, log on to www .thomsonedu.com/thomsonnow zinc in food the trace minerals 453 if the body does not need zinc zinc is not absorbed and is excreted in shed intestinal cells instead. -thus, zinc absorption is reduced when the body does not need zinc. -the pancreas uses zinc to make digestive enzymes and secretes them into the intestine. -mucosal cells in the intestine store excess zinc in metallothionein. -if the body needs zinc metallothionein releases zinc to albumin and transferrin for transport to the rest of the body. -blood. -in healthy individuals, transferrin is usually less than 50 percent saturated with iron, but in iron overload, it is more saturated. -diets that deliver more than twice as much iron as zinc leave too few transferrin sites available for zinc. -the result is poor zinc absorption. -the converse is also true: large doses of zinc inhibit iron absorption. -large doses of zinc create a similar problem with another essential mineral, cop- per. -these nutrient interactions highlight one of the many reasons why people should use supplements conservatively, if at all: supplementation can easily create imbalances. -zinc deficiency severe zinc deficiencies are not widespread in developed countries, but they do occur in vulnerable groups pregnant women, young children, the elderly, and the poor. -human zinc deficiency was first reported in the 1960s in children and adolescent boys in egypt, iran, and turkey. -children have especially high zinc needs because they are growing rapidly and synthesizing many zinc-containing proteins, and the native diets among those populations were not meeting these needs. -middle eastern diets are typically low in the richest zinc source, meats, and the staple foods are legumes, unleavened breads, and other whole-grain foods all high in fiber and phytates, which inhibit zinc absorption. -* figure 13-7 shows the severe growth retardation and mentions the immature sexual development characteristic of zinc deficiency. -in addition, zinc deficiency hinders digestion and absorption, causing diarrhea, which worsens malnutrition not only for zinc, but for all nutrients. -it also impairs the immune response, mak- ing infections likely among them, gi tract infections, which worsen malnutrition, including zinc malnutrition (a classic downward spiral of events).26 chronic zinc deficiency damages the central nervous system and brain and may lead to poor motor development and cognitive performance. -because zinc deficiency directly impairs vitamin a metabolism, vitamin a deficiency symptoms often appear. -zinc * unleavened bread contains no yeast, which normally breaks down phytates during fermentation. -figure 13-7 zinc-deficiency symp- tom the stunted growth of dwarfism the growth retardation, known as dwarfism, is rightly ascribed to zinc defi- ciency because it is partially reversible when zinc is restored to the diet. -n o t s e v l a g t a s a x e t f o y t i s r e v i n u , d a e t s n a s . -h the egyptian man on the right is an adult of average height. -the egyptian boy on the left is 17 years old but is only 4 feet tall, like a 7-year-old in the united states. -his genitalia are like those of a 6-year-old. -454 chapter 13 zinc is highest in protein-rich foods such as oysters, beef, poultry, legumes, and nuts. -deficiency also disturbs thyroid function and the metabolic rate. -it alters taste, causes loss of appetite, and slows wound healing in fact, its symptoms are so per- vasive that generalized malnutrition and sickness are more likely to be the diagno- sis than simple zinc deficiency. -zinc toxicity high doses (over 50 milligrams) of zinc may cause vomiting, diarrhea, headaches, exhaustion, and other symptoms. -an upper level for adults was set at 40 mil- ligrams based on zinc s interference in copper metabolism an effect that, in ani- mals, leads to degeneration of the heart muscle. -. -c n i s o i d u t s a r a l o p zinc recommendations and sources figure 13-8 shows zinc amounts in foods per serving. -zinc is highest in protein- rich foods such as shellfish (especially oysters), meats, poultry, milk, and cheese. -legumes and whole-grain products are good sources of zinc if eaten in large quan- tities; in typical u.s. diets, the phytate content of grains is not high enough to im- pair zinc absorption. -vegetables vary in zinc content depending on the soil in which they are grown. -average intakes in the united states are slightly higher than recommendations. -figure 13-8 zinc in selected foods see the how to section on p. 329 for more information on using this figure. -food serving size (kcalories) 0 2 4 6 8 10 12 milligrams c (31 kcal) c fresh (22 kcal) c cooked (99 kcal) bread, whole wheat cornflakes, fortified spaghetti pasta 1 oz slice (70 kcal) 1 oz (110 kcal) 1 2 1 10"-round (234 kcal) 1 2 c cooked (22 kcal) 1 2 c shredded raw (24 kcal) 1 medium baked w/skin (133 kcal) 3 4 1 medium raw (109 kcal) 1 medium raw (62 kcal) 1 2 1 slice (92 kcal) 1 c reduced-fat 2% (121 kcal) 1 c low-fat (155 kcal) 11 2 oz (171 kcal) 1 2 1 2 2 tbs (188 kcal) 1 oz dry (165 kcal) 1 2 3 oz broiled (244 kcal) 3 oz roasted (140 kcal) tortilla, flour broccoli carrots potato tomato juice banana orange strawberries watermelon milk yogurt, plain cheddar cheese cottage cheese pinto beans peanut butter sunflower seeds tofu (soybean curd) ground beef, lean chicken breast tuna, canned in water 3 oz (99 kcal) egg c low-fat 2% (101 kcal) c cooked (117 kcal) 1 hard cooked (78 kcal) c (76 kcal) excellent, and sometimes unusual, sources: 3 oz cooked (139 kcal) oysters 3 oz broiled (172 kcal) sirloin steak, lean 3 oz cooked (94 kcal) crab rda for men rda for women zinc meat, fish, and poultry (red) are concentrated sources of zinc. -milk (white) and legumes (brown) contain some zinc. -key: breads and cereals vegetables fruits milk and milk products legumes, nuts, seeds meats best sources per kcalorie the trace minerals 455 zinc supplementation in developed countries, most people obtain enough zinc from the diet without resort- ing to supplements. -in developing countries, zinc supplements play a major role in the treatment of childhood infectious diseases. -zinc supplements effectively reduce the incidence of disease and death associated with diarrhea.27 the use of zinc lozenges to treat the common cold has been controversial and in- conclusive, with some studies finding them effective and others not.28 the different study results may reflect the effectiveness of various zinc compounds. -some studies using zinc gluconate report shorter duration of cold symptoms, whereas most stud- ies using other combinations of zinc report no effect. -common side effects of zinc lozenges include nausea and bad taste reactions. -in summary zinc-requiring enzymes participate in a multitude of reactions affecting growth, vitamin a activity, and pancreatic digestive enzyme synthesis, among others. -both dietary zinc and zinc-rich pancreatic secretions (via enteropancre- atic circulation) are available for absorption. -absorption is monitored by a special binding protein (metallothionein) in the intestine. -protein-rich foods derived from animals are the best sources of bioavailable zinc. -fiber and phy- tates in cereals bind zinc, limiting absorption. -growth retardation and sexual immaturity are hallmark symptoms of zinc deficiency. -these facts and others are included in the following table. -zinc rda men: 11 mg/day women: 8 mg/day upper level adults: 40 mg/day chief functions in the body part of many enzymes; associated with the hormone insulin; involved in making genetic material and proteins, immune reactions, transport of vitamin a, taste perception, wound healing, the making of sperm, and the normal development of the fetus significant sources protein-containing foods: red meats, shellfish, whole grains; some fortified cereals deficiency symptomsa growth retardation, delayed sexual maturation, impaired immune function, hair loss, eye and skin lesions, loss of appetite toxicity symptoms loss of appetite, impaired immunity, low hdl, copper and iron deficiencies aa rare inherited disease of zinc malabsorption, acrodermatitis (ak-roh-der-ma-tie-tis) enteropathica (en-ter-oh-path-ick- ah), causes additional and more severe symptoms. -iodine traces of the iodine ion (called iodide) are indispensable to life. -in the gi tract, io- dine from foods becomes iodide. -this chapter uses the term iodine when referring to the nutrient in foods and iodide when referring to it in the body. -iodide occurs in the body in minuscule amounts, but its principal role in the body and its requirement are well established. -iodide roles in the body iodide is an integral part of the thyroid hormones that regulate body temperature, metabolic rate, reproduction, growth, blood cell production, nerve and muscle function, and more. -by controlling the rate at which the cells use oxygen, these hormones influence the amount of energy released dur- ing basal metabolism. -the ion form of iodine is called iodide. -the thyroid gland releases tetraiodothyro- nine (t4), commonly known as thyroxine (thigh-rocks-in), to its target tissues. -upon reaching the cells, t4 is deiodinated to tri- iodothyronine (t3), which is the active form of the hormone. -456 chapter 13 figure 13-9 tom the enlarged thyroid of goiter iodine-deficiency symp- s k r o w e g a m i e h t / h c i r m m e a d b o b in iodine deficiency, the thyroid gland enlarges a condition known as simple goiter. -thyroid-stimulating hormone is also called thyrotropin. -examples of goitrogen-containing foods: cabbage, spinach, radishes, rutabagas soybeans, peanuts peaches, strawberries the underactivity of the thyroid gland is known as hypothyroidism and may be caused by iodine deficiency or any number of other causes. -without treatment, an infant with congenital hypothyroidism will develop the physical and mental retarda- tion of cretinism. -iodized salt contains about 60 g iodine per gram salt. -on average, 1/2 tsp iodized salt provides the rda for iodine. -goiter (goy-ter): an enlargement of the thyroid gland due to an iodine deficiency, malfunction of the gland, or overconsumption of a goitrogen. -goiter caused by iodine deficiency is simple goiter. -goitrogen (goy-troh-jen): a substance that enlarges the thyroid gland and causes toxic goiter. -goitrogens occur naturally in such foods as cabbage, kale, brussels sprouts, cauliflower, broccoli, and kohlrabi. -cretinism (cree-tin-ism): a congenital disease characterized by mental and physical retardation and commonly caused by maternal iodine deficiency during pregnancy. -iodine deficiency the hypothalamus regulates thyroid hormone production by controlling the release of the pituitary s thyroid-stimulating hormone (tsh). -with iodine deficiency, thyroid hormone production declines, and the body responds by secreting more tsh in a futile attempt to accelerate iodide uptake by the thyroid gland. -if a deficiency persists, the cells of the thyroid gland enlarge to trap as much iodide as possible. -sometimes the gland enlarges until it makes a visible lump in the neck, a simple goiter (shown in figure 13-9). -goiter afflicts about 200 million people the world over, many of them in south america, asia, and africa. -in all but 4 percent of these cases, the cause is iodine de- ficiency. -as for the 4 percent (8 million), most have goiter because they regularly eat excessive amounts of foods that contain an antithyroid substance (goitro- gen) whose effect is not counteracted by dietary iodine. -the goitrogens present in plants remind us that even natural components of foods can cause harm when eaten in excess. -goiter may be the earliest and most obvious sign of iodine deficiency, but the most tragic and prevalent damage occurs in the brain. -children with even a mild iodine deficiency typically have goiters and perform poorly in school. -with sus- tained treatment, however, mental performance in the classroom as well as thyroid function improves.29 a severe iodine deficiency during pregnancy causes the extreme and irreversible mental and physical retardation known as cretinism. -cretinism affects approx- imately 6 million people worldwide and can be averted by the early diagnosis and treatment of maternal iodine deficiency. -a worldwide effort to provide iodized salt to people living in iodine-deficient areas has been dramatically successful. -because iron deficiency is common among people with iodine deficiency and because iron deficiency reduces the effectiveness of iodized salt, dual fortification with both iron and iodine may be most beneficial.30 iodine toxicity excessive intakes of iodine can interfere with thyroid function and enlarge the glands, just as deficiency can.31 during pregnancy, exposure to excessive iodine from foods, prenatal supplements, or medications is especially damaging to the developing infant. -an infant exposed to toxic amounts of iodine during gestation may develop a goiter so severe as to block the airways and cause suffocation. -the upper level is over 1100 micrograms per day for an adult sev- eral times higher than average intakes. -iodine recommendations and sources the ocean is the world s major source of iodine. -in coastal areas, seafood, water, and even iodine-containing sea mist are dependable iodine sources. -further inland, the amount of iodine in foods is variable and generally reflects the amount present in the soil in which plants are grown or on which animals graze. -landmasses that were once under the ocean have soils rich in iodine; those in flood-prone areas where water leaches iodine from the soil are poor in iodine. -in the united states and canada, the iodization of salt has elimi- nated the widespread misery caused by iodine deficiency during the 1930s, but iodized salt is not available in many parts of the world. -some countries add iodine to bread, fish paste, or drinking water instead. -although average consumption of iodine in the united states exceeds recom- mendations, it falls below toxic levels. -some of the excess iodine in the u.s. diet stems from fast foods, which use iodized salt liberally. -some iodine comes from bak- ery products and from milk. -the baking industry uses iodates (iodine salts) as dough conditioners, and most dairies feed cows iodine-containing medications and use iodine to disinfect milking equipment. -now that these sources have been iden- tified, food industries have reduced their use of these compounds, but the sudden emergence of this problem points to a need for continued surveillance of the food supply. -processed foods in the united states use regular salt, not iodized salt. -the recommended intake of iodine for adults is a minuscule amount. -the need for iodine is easily met by consuming seafood, vegetables grown in iodine-rich soil, and iodized salt. -in the united states, labels indicate whether salt is iodized; in canada, all table salt is iodized. -the trace minerals 457 e r o o m . -m g i a r c only iodized salt has had iodine added. -in summary iodide, the ion of the mineral iodine, is an essential component of the thyroid hormone. -an iodine deficiency can lead to simple goiter (enlargement of the thyroid gland) and can impair fetal development, causing cretinism. -iodiza- tion of salt has largely eliminated iodine deficiency in the united states and canada. -the table provides a summary of iodine. -iodine rda adults: 150 g/day upper level 1100 g/day chief functions in the body a component of two thyroid hormones that help to regulate growth, development, and metabolic rate significant sources iodized salt, seafood, bread, dairy products, plants grown in iodine-rich soil and animals fed those plants deficiency disease simple goiter, cretinism deficiency symptoms underactive thyroid gland, goiter, mental and physical retardation in infants (cretinism) toxicity symptoms underactive thyroid gland, elevated tsh, goiter selenium the essential mineral selenium shares some of the chemical characteristics of the mineral sulfur. -this similarity allows selenium to substitute for sulfur in the amino acids methionine, cysteine, and cystine.32 selenium roles in the body selenium is one of the body s antioxidant nutrients, working primarily as a part of proteins most notably, the enzyme glutathione peroxidase.33 glutathione peroxidase and vitamin e work in tandem. -glutathione peroxidase prevents free-radical formation, thus blocking the chain reaction before it begins; if free radicals do form and a chain reaction starts, vitamin e stops it. -(highlight 11 describes free-radical formation, chain reactions, and antioxidant ac- tion in detail.) -another enzyme that converts the thyroid hormone to its active form also contains selenium. -selenium deficiency selenium deficiency is associated with a heart disease that is prevalent in regions of china where the soil and foods lack selenium. -al- though the primary cause of this heart disease is probably a virus, selenium de- ficiency appears to predispose people to it, and adequate selenium seems to prevent it. -selenium and cancer some research suggests that selenium may protect against some types of cancers.34 given the potential for harm and the lack of conclusive ev- idence, however, recommendations to take selenium supplements would be prema- ture and perhaps ineffective as well. -selenium from foods appears to be more effective in inhibiting cancer growth than selenium from supplements. -such a find- ing reinforces a theme that has been repeated throughout this text foods offer many more health benefits than supplements. -selenium recommendations and sources selenium is found in the soil, and therefore in the crops grown for consumption.35 people living in regions with sele- nium-poor soil may still get enough selenium, partly because they eat vegetables key antioxidant nutrients: vitamin c, vitamin e, beta-carotene selenium the heart disease associated with selenium deficiency is named keshan (kesh-an or ka-shawn) disease for one of the provinces of china where it was studied. -keshan disease is characterized by heart enlargement and insufficiency; fibrous tis- sue replaces the muscle tissue that nor- mally composes the middle layer of the walls of the heart. -selenium (se-leen-ee-um): a trace element. -458 chapter 13 and grains transported from other regions and partly because they eat meats and other animal products, which are reliable sources of selenium. -average intakes in the united states and canada are above the rda, which is based on the amount needed to maximize glutathione peroxidase activity. -selenium toxicity because high doses of selenium are toxic, an upper level has been set. -selenium toxicity causes loss and brittleness of hair and nails, garlic breath odor, and nervous system abnormalities. -in summary selenium is an antioxidant nutrient that works closely with the glutathione peroxidase enzyme and vitamin e. selenium is found in association with pro- tein in foods. -deficiencies are associated with a predisposition to a type of heart abnormality known as keshan disease. -see the table below for a sum- mary of selenium. -deficiency symptoms predisposition to heart disease characterized by cardiac tissue becoming fibrous (keshan dis- ease) toxicity symptoms loss and brittleness of hair and nails; skin rash, fatigue, irritability, and nervous system disor- ders; garlic breath odor selenium rda adults: 55 g/day upper level adults: 400 g/day chief functions in the body defends against oxidation; regulates thyroid hormone significant sources seafood, meat, whole grains, fruits, and veg- etables (depending on soil content) copper the body contains about 100 milligrams of copper. -it is found in a variety of cells and tissues. -copper roles in the body copper serves as a constituent of several enzymes. -the copper-containing enzymes have diverse metabolic roles with one common characteristic: all involve reactions that consume oxygen or oxygen radicals. -for ex- ample, copper-containing enzymes catalyze the oxidation of ferrous iron to ferric iron. -*36 copper s role in iron metabolism makes it a key factor in hemoglobin syn- thesis. -two copper- and zinc-containing enzymes participate in the body s natural defense against free radicals. -** still another copper enzyme helps to manufacture collagen and heal wounds. -copper, like iron, is needed in many of the metabolic re- actions related to the release of energy. -copper deficiency and toxicity typical u.s. diets provide adequate amounts of copper and deficiency is rare. -in animals, copper deficiency raises blood cholesterol and damages blood vessels, raising questions about whether low dietary copper might contribute to cardiovascular disease in humans. -* the copper-containing enzyme ceruloplasmin participates in the oxidation of ferrous iron to ferric iron. -** two copper-containing superoxide dismutase enzymes defend against free radicals. -the copper-containing enzyme lysyl oxidase helps synthesize connective tissues. -the copper-containing enzyme cytochrome c oxidase participates in the electron transport chain. -the trace minerals 459 some genetic disorders create a copper toxicity, but excessive intakes from foods are unlikely. -excessive intakes from supplements may cause liver damage, and therefore an upper level has been set. -two rare genetic disorders affect copper status in opposite directions. -in menkes disease, the intestinal cells absorb copper, but cannot release it into circulation, causing a life-threatening deficiency. -in wilson s disease, copper accumulates in the liver and brain, creating a life-threatening toxicity. -wilson s disease can be con- trolled by reducing copper intake, using chelating agents such as penicillamine, and taking zinc supplements, which interfere with copper absorption. -(the use of chelation in health care is mentioned in highlight 18 s discussion of alternative therapies.) -copper recommendations and sources the richest food sources of copper are legumes, whole grains, nuts, shellfish, and seeds. -over half of the copper from foods is absorbed, and the major route of elimination appears to be bile. -water may also pro- vide copper, depending on the type of plumbing pipe and the hardness of the water. -in summary copper is a component of several enzymes, all of which are involved in some way with oxygen or oxidation. -some act as antioxidants; others are essential to iron metabolism. -legumes, whole grains, and shellfish are good sources of copper. -see the table for a summary of copper facts. -copper rda significant sources adults: 900 g/day seafood, nuts, whole grains, seeds, legumes upper level deficiency symptoms adults: 10,000 g/day (10 mg/day) anemia, bone abnormalities chief functions in the body toxicity symptoms necessary for the absorption and use of iron in the formation of hemoglobin; part of several enzymes liver damage manganese the human body contains a tiny 20 milligrams of manganese. -most of it can be found in the bones and metabolically active organs such as the liver, kidneys, and pancreas. -manganese roles in the body manganese acts as a cofactor for many enzymes that facilitate the metabolism of carbohydrate, lipids, and amino acids. -in addition, manganese-containing metalloenzymes assist in bone formation and the conver- sion of pyruvate to a tca cycle compound. -manganese deficiency and toxicity manganese requirements are low, and many plant foods contain significant amounts of this trace mineral, so deficiencies are rare. -as is true of other trace minerals, however, dietary factors such as phytates inhibit its absorption. -in addition, high intakes of iron and calcium limit man- ganese absorption, so people who use supplements of those minerals regularly may impair their manganese status. -toxicity is more likely to occur from an environment contaminated with man- ganese than from dietary intake.37 miners who inhale large quantities of man- ganese dust on the job over prolonged periods show symptoms of a brain disease, 460 chapter 13 key bone nutrients: vitamin d, vitamin k, vitamin a calcium, phosphorus, magnesium, fluoride for perspective, 1 part per million (1 ppm) is approximately 1 mg per liter. -to prevent fluorosis: monitor the fluoride content of the local water supply. -supervise toddlers when they brush their teeth using only a little toothpaste (pea- size amount). -use fluoride supplements only as pre- scribed by a physician. -fluorapatite (floor-app-uh-tite): the stabilized form of bone and tooth crystal, in which fluoride has replaced the hydroxyl groups of hydroxyapatite. -fluorosis (floor-oh-sis): discoloration and pitting of tooth enamel caused by excess fluoride during tooth development. -along with abnormalities in appearance and behavior. -still, an upper level has been established based on intakes from food, water, and supplements. -manganese recommendations and sources grain products make the great- est contribution of manganese to the diet. -with insufficient information to establish an rda, an ai was set based on average intakes. -in summary manganese-dependent enzymes are involved in bone formation and various metabolic processes. -because manganese is widespread in plant foods, defi- ciencies are rare, although regular use of calcium and iron supplements may limit manganese absorption. -a summary of manganese appears in the table below. -manganese ai men: 2.3 mg/day women: 1.8 mg/day upper level adults: 11 mg/day chief functions in the body cofactor for several enzymes; bone formation fluoride significant sources nuts, whole grains, leafy vegetables, tea deficiency symptoms rare toxicity symptoms nervous system disorders fluoride is present in virtually all soils, water supplies, plants, and animals. -only a trace of fluoride occurs in the human body, but with this amount, the crystalline de- posits in bones and teeth are larger and more perfectly formed. -fluoride roles in the body as chapter 12 explained, during the mineralization of bones and teeth, calcium and phosphorus form crystals called hydroxyapatite. -then fluoride replaces the hydroxyl (oh) portions of the hydroxyapatite crystal, forming fluorapatite, which makes the bones stronger and the teeth more resist- ant to decay. -dental caries ranks as the nation s most widespread health problem: an esti- mated 95 percent of the population have decayed, missing, or filled teeth. -by inter- fering with a person s ability to chew and eat a wide variety of foods, these dental problems can quickly lead to a multitude of nutrition problems. -where fluoride is lacking, dental decay is common. -drinking water is usually the best source of fluoride, and more than 65 percent of the u.s. population served by public water systems receives optimal levels of flu- oride (see figure 13-10).38 (most bottled waters lack fluoride.) -fluoridation of drink- ing water (to raise the concentration to 1 part fluoride per 1 million parts water) offers the greatest protection against dental caries at virtually no risk of toxicity.39 by fluoridating the drinking water, a community offers its residents, particularly the children, a safe, economical, practical, and effective way to defend against dental caries. -fluoride toxicity too much fluoride can damage the teeth, causing fluorosis.40 for this reason, an upper level has been established. -in mild cases, the teeth develop small white specks; in severe cases, the enamel becomes pitted and permanently stained (as shown in figure 13-11). -fluorosis occurs only during tooth development and cannot be reversed, making its prevention a high priority. -to limit fluoride in- gestion, take care not to swallow fluoride-containing dental products such as tooth- paste and mouthwash. -fluoride recommendations and sources as mentioned earlier, much of the u.s. population has access to water with an optimal fluoride concentration, which typically delivers about 1 milligram per person per day.41 fish and most teas contain appreciable amounts of natural fluoride. -in summary fluoride makes bones stronger and teeth more resistant to decay. -fluoridation of public water supplies can significantly reduce the incidence of dental caries, but excess fluoride during tooth development can cause fluorosis discolored and pitted tooth enamel. -the table below summarizes fluoride information. -the trace minerals 461 figure 13-10 u.s. population with access to fluoridated water through public water systems key: <49% 50% 74% >75% flouride ai men: 3.8 mg/day women: 3.1 mg/day upper level adults: 10 mg/day chief functions in the body maintains health of bones and teeth; helps to make teeth resistant to decay chromium significant sources drinking water (if fluoride containing or fluori- dated), tea, seafood deficiency symptoms susceptibility to tooth decay toxicity symptoms fluorosis (pitting and discoloration of teeth) figure 13-11 fluoride-toxicity symp- tom the mottled teeth of fluorosis / y r a r b i l o t o h p e c n e i c s / i z a r r a m p. . -r d . -c n i , s r e h c r a e s e r o t o h p small organic compounds that enhance insulin s action are called glucose tolerance factors (gtf). -some glucose tolerance factors contain chromium. -chromium is an essential mineral that participates in carbohydrate and lipid me- tabolism. -like iron, chromium assumes different charges. -in chromium, the cr+++ ion is the most stable and most commonly found in foods. -chromium roles in the body chromium helps maintain glucose homeostasis by enhancing the activity of the hormone insulin. -when chromium is lacking, a diabetes-like condition may develop with elevated blood glucose and impaired glu- cose tolerance, insulin response, and glucagon response. -in spite of these relation- ships, research findings suggest that chromium supplements do not effectively improve glucose or insulin responses in diabetes.42 chromium recommendations and sources chromium is present in a variety of foods. -the best sources are unrefined foods, particularly liver, brewer s yeast, and whole grains. -the more refined foods people eat, the less chromium they ingest. -chromium supplements supplement advertisements have succeeded in convincing consumers that they can lose fat and build muscle by taking chromium picolinate. -whether chromium supplements (either picolinate or plain) reduce body fat or im- prove muscle strength remains controversial. -(highlight 14 revisits chromium picoli- nate and other supplements athletes use in the hopes of improving their performance.) -in summary chromium enhances insulin s action. -a deficiency can result in a diabetes-like con- dition. -chromium is widely available in unrefined foods including brewer s yeast, whole grains, and liver. -the following table provides a summary of chromium. -(continued) 462 chapter 13 figure 13-12 cobalt with vitamin b12 h2n co h2c h3c h3c o c h h2c nh2 nh2 c o c cn ch2 ch2 nh2 c o ch3 h3c ch2 ch2 h h n n co+ n n nh2 c o ch2 ch3 ch3 ch2 ch2 c o nh2 ch3 ch2 ch2 ch3 ch3 c o ch ch2 nh o o p o o h ch2 oh oh h h o h h n+ n h h ch3 ch3 the intricate vitamin b12 molecule contains one atom of the mineral cobalt. -the alternative name for vitamin b12, cobalamin, reflects the presence of cobalt in its structure. -molybdenum (mo-lib-duh-num): a trace element. -deficiency symptoms diabetes-like condition toxicity symptoms none reported chromium (continued) ai men: 35 g/day women: 25 g/day chief functions in the body enhances insulin action and may improve glucose tolerance significant sources meats (especially liver), whole grains, brewer s yeast molybdenum molybdenum acts as a working part of several metalloenzymes. -dietary deficien- cies of molybdenum are unknown because the amounts needed are minuscule as little as 0.1 part per million parts of body tissue. -legumes, breads and other grain products, leafy green vegetables, milk, and liver are molybdenum-rich foods. -aver- age daily intakes fall within the suggested range of intakes. -molybdenum toxicity in people is rare. -it has been reported in animal studies, and an upper level has been established. -characteristics of molybdenum toxicity include kidney damage and reproductive abnormalities. -for a summary of molyb- denum facts, see the accompanying table. -in summary molybdenum rda adults: 45 g/day upper level adults: 2 mg/day significant sources legumes, cereals, nuts deficiency symptoms unknown toxicity symptoms chief functions in the body cofactor for several enzymes none reported; reproductive effects in animals other trace minerals research to determine whether other trace minerals are essential is difficult because their quantities in the body are so small and also because human deficiencies are unknown. -guessing their functions in the body can be particularly problematic. -much of the available knowledge comes from research using animals. -nickel may serve as a cofactor for certain enzymes. -silicon is involved in the for- mation of bones and collagen. -vanadium, too, is necessary for growth and bone de- velopment and for normal reproduction. -cobalt is a key mineral in the large vitamin b12 molecule (see figure 13-12), but it is not an essential nutrient and no recommendation has been established. -boron may play a key role in brain activi- ties; in animals, boron strengthens bones.43 in the future, we may discover that many other trace minerals play key nutri- tional roles. -even arsenic famous as a poison used by murderers and known to be a carcinogen may turn out to be essential for human beings in tiny quantities. -it has already proved useful in the treatment of some types of leukemia. -contaminant minerals chapter 12 and this chapter have told of the many ways minerals serve the body maintaining fluid and electrolyte balance, providing structural support to the bones, transporting oxygen, and assisting enzymes. -in contrast to the minerals that the body requires, contaminant minerals impair the body s growth, work capacity, and general health. -contaminant minerals include the heavy metals lead, mer- cury, and cadmium that enter the food supply by way of soil, water, and air pollu- tion. -this section focuses on lead poisoning because it is a serious environmental threat to young children and because reducing blood lead levels in children is a goal of healthy people 2010.44 much of the information on lead applies to the other contaminant minerals as well they all disrupt body processes and impair nutri- tion status similarly. -like other minerals, lead is indestructible; the body cannot change its chem- istry. -chemically similar to nutrient minerals like iron, calcium, and zinc (cations with two positive charges), lead displaces them from some of the metabolic sites they normally occupy but is then unable to perform their roles. -for example, lead competes with iron in heme, but it cannot carry oxygen. -similarly, lead competes with calcium in the brain, but it cannot signal messages from nerve cells. -excess lead in the blood also deranges the structure of red blood cell membranes, making them leaky and fragile. -lead interacts with white blood cells, too, impairing their ability to fight infection, and it binds to antibodies, thwarting their effort to resist disease. -in addition to its effects on the blood, lead impairs many body systems, most no- tably causing irreversible damage to the central nervous system.45 it impairs such normal activities as growth by interfering with hormone activity.46 it interferes with tooth development and may contribute to dental caries as well.47 even at low levels, blood lead concentrations correlate with poor iq scores.48 in short, lead s interactions in the body have profound adverse effects the greater the exposure, the more dam- aging the effects. -the american academy of pediatrics recommends testing children who have been identified as having a high risk for lead poisoning. -follow-up testing is critical to ensuring appropriate intervention.49 children with high blood lead lev- els are treated with chelating agents medications that bind specifically to lead and carry it out in the urine.50 table 13-1 lists symptoms of lead toxicity. -lead typifies the ways all heavy metals behave in the body: they interfere with nutrients that are trying to do their jobs. -the good guy nutrients are shoved aside by the bad guy contaminants. -then, when the contaminants cannot perform the roles of the nutrients, health diminishes. -to safeguard our health, we must defend ourselves against contamination by eating nutrient-rich foods and preserving a clean environment. -closing thoughts on the nutrients this chapter completes the introductory lessons on the nutrients. -each nutrient from the amino acids to zinc has been described rather thoroughly its chemistry, roles in the body, sources in the diet, symptoms of deficiency and toxicity, and influences on health and disease. -such a detailed examination is informative, but it can also be misleading. -it is important to step back from the detailed study of the individual nu- trients to look at them as a whole. -after all, people eat foods, not nutrients, and most foods deliver dozens of nutrients. -furthermore, nutrients work cooperatively with each other in the body; their actions are most often interactions. -this chapter alone mentioned how iron depends on vitamin c to keep it in its active form and copper to incorporate it into hemoglobin, how zinc is needed to activate and transport vitamin the trace minerals 463 table 13-1 symptoms of lead toxicity in children learning disabilities (reduced short-term memory; impaired concentration) low iq behavior problems slow growth iron-deficiency anemia dental caries sleep disturbances (night waking, restlessness, head banging) nervous system disorders; seizures slow reaction time; poor coordination impaired hearing in adults hypertension reproductive complications kidney failure heavy metals: mineral ions such as mercury and lead, so called because they are of relatively high atomic weight. -many heavy metals are poisonous. -464 chapter 13 in summary the trace minerals a, and how both iodine and selenium are needed for the synthesis of thyroid hor- mone. -the accompanying table condenses the information on the trace minerals for your review. -mineral and chief functions iron part of the protein hemoglobin, which carries oxygen in the blood; part of the protein myoglobin in muscles, which makes oxygen available for muscle contraction; necessary for energy metabolism zinc part of insulin and many enzymes; involved in making genetic material and proteins, immune reactions, transport of vitamin a, taste perception, wound healing, the making of sperm, and normal fetal development iodine a component of the thyroid hormones that help to regulate growth, development, and metabolic rate selenium part of an enzyme that defends against oxidation; regulates thyroid hormone copper helps form hemoglobin; part of several enzymes deficiency symptoms anemia: weakness, fatigue, headaches; im- paired work performance; impaired immunity; pale skin, nail beds, mucous membranes, and palm creases; concave nails; inability to regu- late body temperature; pica toxicity symptomsa gi distress; iron overload: infections, fatigue, joint pain, skin pigmentation, organ damage significant sources red meats, fish, poultry, shellfish, eggs, legumes, dried fruits growth retardation, delayed sexual maturation, impaired immune function, hair loss, eye and skin lesions, loss of appetite. -loss of appetite, im- paired immunity, low hdl, copper and iron deficiencies protein-containing foods: red meats, fish, shellfish, poultry, whole grains; fortified cereals underactive thyroid gland, goiter, mental and physical retardation (cretinism) underactive thyroid gland, elevated tsh, goiter iodized salt; seafood; plants grown in iodine-rich soil and animals fed those plants associated with keshan disease nail and hair brittleness and loss; fatigue, irri- tability, and nervous system disorders, skin rash, garlic breath odor seafoods, organ meats; other meats, whole grains, fruits, and vegetables (depending on soil content) anemia, bone abnormalities liver damage seafood, nuts, legumes, whole grains, seeds manganese cofactor for several enzymes; bone formation rare fluoride maintains health of bones and teeth; confers decay resistance on teeth susceptibility to tooth decay chromium enhances insulin action, may improve glucose intolerance diabetes-like condition molybdenum cofactor for several enzymes unknown a acute toxicities of many minerals cause abdominal pain, nausea, vomiting, and diarrhea. -nervous symptom disorders nuts, whole grains, leafy vegetables, tea fluorosis (pitting and discoloration) of teeth, drinking water (if fluoridated), tea, seafood none reported meats (liver), whole grains, brewer s yeast none reported legumes, cereals, nuts how much of each particular nutrient does the body need? -estimates fall some- where between intakes that are inadequate and cause illness and intakes that are excessive and cause illness. -a wide range of intakes that support health, to varying degrees, lies between deficiency and toxicity. -in the past, nutrient needs were deter- mined by how much was needed to prevent deficiency symptoms. -if lack of a nutri- the trace minerals 465 ent caused illness, it was defined as essential. -today, nutrient needs are based on how much is needed to support optimal health. -the amount of vitamin c needed to prevent scurvy is much less than the amount correlated with reducing the risk of cancer, for example. -furthermore, nutrients are being examined within the context of the whole diet. -health benefits are not credited to vitamin c alone, but also to the vitamin c rich fruits and vegetables that provide many other nutrients and nonnutrients (phytochemicals) important to health. -people can also improve their health with physical activity. -energy expenditure is unlike money expenditure: it is desirable to spend energy, not to save it (within reason, of course). -the more energy people spend, the more food they can afford to eat food that delivers both nutrients and pleasure. -the next chapter presents de- tails on nutrition and physical activity. -nutrition portfolio www.thomsonedu.com/thomsonnow trace minerals from a variety of foods, especially those in the meat and meat alter- nate group, support many of your body s activities. -examine the variety in your food intake, taking particular notice of how often you include meats, seafood, poultry, or legumes, weekly. -describe the advantages of using iodized salt. -determine whether your community provides fluoridated water. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 13, then to nutrition on the net. -websites learn more about iron overload from the iron overload diseases association: www.ironoverload.org learn more about iodine and thyroid disease from the american thyroid association: www.thyroid.org search for minerals at the american dietetic associa- learn more about lead in paint, dust, and soil from the tion: www.eatright.org search for the individual minerals by name at the u.s. government health information site: www.healthfinder.gov nutrition calculations centers for disease control or environmental protection agency: www.cdc.gov/lead or www.epa.gov/lead for additional practice log on to www.thomsonedu.com/thomsonnow. -go to chapter 13, then to nutrition calculations. -once you have mastered these examples, you will under- stand minerals a little better and be prepared to examine your own food choices. -be sure to show your calculations for each problem. -(see p. 468 for answers.) -1. for each of these minerals, note the unit of measure for recommendations: iron zinc iodine selenium copper manganese fluoride chromium molybdenum 2. appreciate foods for their iron density. -following is a list of foods with the energy amount and the iron content per serving (p. 466). -a. rank these foods by iron per serving. -b. calculate the iron density (divide milligrams by kcalories) for these foods and rank them by their iron per kcalorie. -466 chapter 13 c. name three foods that are higher on the second list than they were on the first list. -d. what do these foods have in common? -food milk, fat-free, 1 c cheddar cheese, 1 oz broccoli, cooked from fresh, chopped, 1 c sweet potato, baked in skin, 1 ea cantaloupe melon, 1 2 carrots, from fresh, 1 2 c whole-wheat bread, 1 slice green peas, cooked from frozen, 1 2 c apple, medium sirloin steak, lean, 4 oz pork chop, lean, broiled, 1 ea iron (mg) energy (kcal) iron density (mg/kcal) 0.10 0.19 1.31 0.51 0.56 0.48 0.87 1.26 0.38 3.81 0.66 85 114 44 117 93 35 64 62 125 228 166 study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. distinguish between heme and nonheme iron. -discuss the factors that enhance iron absorption. -(pp. -443 444) 2. distinguish between iron deficiency and iron-deficiency anemia. -what are the symptoms of iron-deficiency ane- mia? -(pp. -445 447) 1. iron absorption is impaired by: a. heme. -b. phytates. -c. vitamin c. d. mfp factor. -2. which of these people is least likely to develop an iron deficiency? -a. -3-year-old boy b. -52-year-old man c. 17-year-old girl d. 24-year-old woman 3. what causes iron overload? -what are its symptoms? -3. which of the following would not describe the blood (p. 448) cells of a severe iron deficiency? -4. describe the similarities and differences in the absorp- tion and regulation of iron and zinc. -(pp. -443 445, 452 453) 5. discuss possible reasons for a low intake of zinc. -what factors affect the bioavailability of zinc? -(p. 454) 6. describe the principal functions of iodide, selenium, copper, manganese, fluoride, chromium, and molybde- num in the body. -(pp. -455 462) 7. what public health measure has been used in preventing simple goiter? -what measure has been recommended for protection against tooth decay? -(pp. -456 457, 460 461) 8. discuss the importance of balanced and varied diets in obtaining the essential minerals and avoiding toxicities. -(pp. -463 465) a. anemic b. microcytic c. pernicious d. hypochromic 4. which provides the most absorbable iron? -a. -1 apple b. -1 c milk c. 3 oz steak d. 1 2 c spinach 5. the intestinal protein that helps to regulate zinc absorp- tion is: a. albumin. -b. ferritin. -c. hemosiderin. -d. metallothionein. -9. describe some of the ways trace minerals interact with 6. a classic sign of zinc deficiency is: each other and with other nutrients. -(p. 463) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 468. a. anemia. -b. goiter. -c. mottled teeth. -d. growth retardation. -the trace minerals 467 7. cretinism is caused by a deficiency of: 9. fluorosis occurs when fluoride: a. iron. -b. zinc. -c. iodine. -d. selenium. -a. is excessive. -b. is inadequate. -c. binds with phosphorus. -d. interacts with calcium. -8. the mineral best known for its role as an antioxidant is: 10. which mineral enhances insulin activity? -a. copper. -b. selenium. -c. manganese. -d. molybdenum. -a. zinc b. iodine c. chromium d. manganese references 1. m. w. hentze, m. u. muckenthaler, and n. c. andrews, molecular control of mam- malian iron metabolism, cell 117 (2004): 285-297. -2. r. e. fleming and b. r. bacon, orchestra- tion of iron homeostasis, new england journal of medicine 352 (2005): 1741-1744; chung and wessling-resnick, lessons learned from genetic and nutritional iron deficiencies, nutrition reviews 62 (2004): 212-220. -3. e. g. theil, iron, ferritin, and nutrition, annual review of nutrition 24 (2004): 327-343. -4. committee on dietary reference intakes, dietary reference intakes for vitamin a, vita- min k, arsenic, boron, chromium, copper, iodine, iron, manganese, molybdenum, nickel, silicon, vanadium, and zinc (washington, d.c.: national academy press, 2001), p. 315. -5. s. miret, r. j. simpson, and a. t. mckie, physiology and molecular biology of dietary iron absorption, annual review of nutrition 23 (2003): 283-301. -6. r. f. hurrell and coauthors, meat protein fractions enhance nonheme iron absorption in humans, journal of nutrition 136 (2006): 2808-2812. -7. committee on dietary reference intakes, 2001, p. 351. -8. e. nemeth and t. ganz, regulation of iron metabolism by hepcidin, annual review of nutrition 26 (2006): 323-342. -9. j. l. beard and j. r. connor, iron status and neural functioning, annual review of nutri- tion 23 (2003): 41-58. -10. world health organization, http://www.who.int/nut/ida.htm. -11. k. g. nead and coauthors, overweight chil- dren and adolescents: a risk group for iron deficiency, pediatrics 114 (2004): 104-108. -12. iron deficiency united states, 1999-2000, morbidity and mortality weekly report 51 (2002): 897-899. -13. k. c. white, anemia is a poor predictor of iron deficiency among toddlers in the united states: for heme the bell tolls, pedi- atrics 115 (2005): 315-320. -14. m. j. koury and p. ponka, new insights into erythropoiesis: the roles of folate, vitamin b12, and iron, annual review of nutrition 24 (2004): 105-131. -15. t. brownlie and coauthors, marginal iron deficiency without anemia impairs aerobic adaptation among previously untrained women, american journal of clinical nutrition 75 (2002): 734-742. -16. j. beard, iron deficiency alters brain devel- opment and functioning, journal of nutrition 133 (2003): 1468s-1472s; e. m. ross, evalua- tion and treatment of iron deficiency in adults, nutrition in clinical care 5 (2002): 220-224. -17. p. c. adams and coauthors, hemochro- matosis and iron-overload screening in a racially diverse population, new england journal of medicine 352 (2005): 1769-1778; a. l. m. heath and s. j. fairweather-tait, health implications of iron overload: the role of diet and genotype, nutrition reviews 61 (2003): 45-62. -18. a. pietrangelo, hereditary hemochromato- sis, annual review of nutrition 26 (2006): 251-270. -19. d. lee, a. r. folsom, and d. r. jacobs, iron, zinc, and alcohol consumption and mortal- ity from cardiovascular diseases: the iowa women s health study, american journal of clinical nutrition 81 (2005): 787-791; u. ramakrishnan, e. kuklina, and a. d. stein, iron stores and cardiovascular disease risk factors in women of reproductive age in the united states, american journal of clinical nutrition 76 (2002): 1256-1260. -20. m. b. reddy and l. clark, iron, oxidative stress, and disease risk, nutrition reviews 62 (2004): 120-124; j. l. derstine and coau- thors, iron status in association with cardio- vascular disease risk in 3 controlled feeding studies, american journal of clinical nutrition 77 (2003): 56-62. -21. a. g. mainous and coauthors, iron, lipids, and risk of cancer in the framingham off- spring cohort, american journal of epidemiol- ogy 160 (2005): 1115-1122. -22. committee on dietary reference intakes, 2001, p. 351. -23. j. r. backstrand, the history and future of food fortification in the united states: a public health perspective, nutrition reviews 60 (2002): 15-26. -24. h. tapiero and k. d. tew, trace elements in human physiology and pathology: zinc and metallothioneins, biomedicine and pharma- cotherapy 57 (2003): 399-411. -25. c. l. adams and coauthors, zinc absorption from a low-phytic acid maize, american journal of clinical nutrition 76 (2002): 556-559. -26. c. f. walker and r. e. black, zinc and the risk for infectious disease, annual review of nutrition 24 (2004): 255-275. -27. j. m. m. gardner and coauthors, zinc sup- plementation and psychosocial stimulation: effects on the development of undernour- ished jamaican children, american journal of clinical nutrition 82 (2005): 399-405; t. a. strand and coauthors, effectiveness and efficacy of zinc for the treatment of acute diarrhea in young children, pediatrics 109 (2002): 898-903; n. bhandari and coauthors, substantial reduction in severe diarrheal morbidity by daily zinc supplementation in young north indian children, pediatrics 109 (2002): e86. -28. g. a. eby and w. w. halcomb, ineffective- ness of zinc gluconate nasal spray and zinc orotate lozenges in common-cold treat- ment: a double-blind placebo-controlled clinical trial, alternative therapies in health and medicine 12 (2006): 34-48; b. arroll, non-antibiotic treatments for upper-respira- tory tract infections (common cold), respira- tory medicine 99 (2005): 1477-1484; b. h. mcelroy and s. p. miller, effectiveness of zinc gluconate glycine lozenges (cold-eeze) against the common cold in school-aged subjects: a retrospective chart review, ameri- can journal of therapeutics 9 (2002): 472-475. -29. m. b. zimmermann and coauthors, rapid relapse of thyroid dysfunction and goiter in school-age children after discontinuation of salt iodization, american journal of clinical nutrition 79 (2004): 642-645. -30. m. b. zimmerman, the influence of iron status on iodine utilization and thyroid function, annual review of nutrition 26 (2006): 367-389. -31. w. teng and coauthors, effect of iodine intake on thyroid diseases in china, new england journal of medicine 354 (2006): 2783- 2793. -32. d. m. driscoll and p. r. copeland, mecha- nism and regulation of selenoprotein syn- thesis, annual review of nutrition 23 (2003): 17-40. -33. r. f. burk and k. e. hill, selenoprotein p: an extracellular protein with unique physical characteristics and a role in selenium home- ostasis, annual review of nutrition 25 (2005): 215-235. -34. a. j. duffield-lillico, i. shureiqi, and s. m. lippman, can selenium prevent colorectal cancer? -a signpost from epidemiology, journal of the national cancer institute 96 (2004): 1645-1647. -35. j. w. finley, selenium accumulation in plant foods, nutrition reviews 63 (2005): 196-202. -36. n. e. hellman and j. d. gitlin, ceruloplas- min metabolism and function, annual review of nutrition 22 (2002): 439-458. -37. j. w. finley, does environmental exposure to manganese pose a health risk to healthy adults? -nutrition reviews 62 (2004): 148-153. -38. populations receiving optimally fluoridated public drinking water united states, 2000, morbidity and mortality weekly report 51 (2002): 144-147. -39. position of the american dietetic associa- tion: the impact of fluoride on health, journal of the american dietetic association 105 (2005): 1620-1628. -40. surveillance for dental caries, dental sealants, tooth retention, edentulism, and enamel fluorosis united states, 1988-1994 and 1999-2002, morbidity and mortality weekly report 54 (2005): 1-44. -468 chapter 13 41. populations receiving optimally fluoridated public drinking water united states, 2000, 2002. -42. m. d. althuis and coauthors, glucose and insulin responses to dietary chromium supplements: a meta-analysis, american journal of clinical nutrition 76 (2002): 148- 155. -43. t. a. devirian and s. l. volpe, the physio- logical effects of dietary boron, critical reviews in food and science nutrition 43 (2003): 219-231. -44. committee on environmental health, lead exposure in children: prevention, detection, and management, pediatrics 116 (2005): answers nutrition calculations 1036-1046; blood lead levels united states, 1999-2002, morbidity and mortality weekly report 54 (2005): 513-527. -45. d. c. bellinger, lead, pediatrics 113 (2004): 1016-1022. -46. s. g. selevan and coauthors, blood lead concentration and delayed puberty in girls, new england journal of medicine 348 (2003): 1527-1536. -47. r. j. billings, r. j. berkowitz, and g. watson, teeth, pediatrics 113 (2004): 1120-1127. -48. r. l. canfield and coauthors, intellectual impairment in children with blood lead concentrations below 10 g per deciliter, new england journal of medicine 348 (2003): 1517-1526. -49. a. r. kemper and coauthors, follow-up testing among children with elevated screening blood lead levels, journal of the american medical association 293 (2005): 2232-2237. -50. k. kalia and s. j. flora, strategies for safe and effective therapeutic measures for chronic arsenic and lead poisoning, journal of occupational health 47 (2005): 1-21; s. p. murphy and coauthors, simple measures of dietary variety are associated with improved dietary quality, journal of the american dietetic association 106 (2006): 425 429. c. broccoli, green peas, and carrots are all higher on the per- 1. iron: mg zinc: mg iodine: g selenium: g copper: g fluoride: mg chromium: g manganese: mg molybdenum: g kcalorie list. -d. they are all vegetables. -2. a. ranked by iron per serving: sirloin steak > broccoli > green study questions (multiple choice) peas > bread > pork chop > cantaloupe > sweet potato > carrots > apple > cheese > milk 1. b 9. a 2. b 3. c 4. c 5. d 6. d 7. c 8. b 10. c b. food iron density (mg/kcal) milk, fat-free, 1 c cheddar cheese, 1 oz 0.10 mg (cid:2) 85 kcal (cid:3) 0.0012 mg/kcal 0.19 mg (cid:2) 114 kcal (cid:3) 0.0017 mg/kcal broccoli, cooked from fresh, chopped, 1 c sweet potato, baked in skin, 1 ea cantaloupe melon, 1 2 carrots, from fresh, 1 2 c whole-wheat bread, 1 slice green peas, cooked from frozen, 1 2 c apple, medium sirloin steak, lean, 4 oz pork chop, lean broiled, 1 ea 1.31 mg (cid:2) 44 kcal (cid:3) 0.0298 mg/kcal 0.51 mg (cid:2) 117 kcal (cid:3) 0.0044 mg/kcal 0.56 mg (cid:2) 93 kcal (cid:3) 0.0060 mg/kcal 0.48 mg (cid:2) 35 kcal (cid:3) 0.0137 mg/kcal 0.87 mg (cid:2) 64 kcal (cid:3) 0.0136 mg/kcal 1.26 mg (cid:2) 62 kcal (cid:3) 0.0203 mg/kcal 0.38 mg (cid:2) 125 kcal (cid:3) 0.0030 mg/kcal 3.81 mg (cid:2) 228 kcal (cid:3) 0.0167 mg/kcal 0.66 mg (cid:2) 166 kcal (cid:3) 0.0040 mg/kcal ranked by iron density (iron per kcalorie): broccoli > green peas > sirloin steak > carrots > bread > cantaloupe > sweet potato > pork chop > apple > cheese > milk highlight 13 highlight phytochemicals and functional foods chapter 13 completes the introductory dis- cussions on the six classes of nutrients carbo- hydrates, lipids, proteins, vitamins, minerals, and water. -in addition to these nutrients, foods contain thousands of nonnutrient com- pounds, including the phytochemicals. -chap- ter 1 introduced the phytochemicals as compounds found in plant-derived foods (phyto means plant) that have biological activ- ity in the body. -research on phytochemicals is unfolding daily, adding to our knowledge of their roles in human health, but there are still many questions and only tentative answers. -just a few of the tens of thousands of phytochemicals have been researched at all, and only a sampling are mentioned in this highlight enough to illustrate their wide variety of food sources and roles in sup- porting health. -the concept that foods provide health benefits beyond those of the nutrients emerged from numerous epidemiological studies showing the protective effects of plant-based diets on cancer and heart disease. -people have been using foods to maintain health and prevent disease for years, but now these foods have been given a name they are called functional foods. -(the accom- panying glossary defines this and other terms.) -as chapter 1 ex- plained, functional foods include all foods (whole, fortified, or modified foods) that have a potentially beneficial effect on health.1 much of this text touts the benefits of nature s functional foods grains rich in dietary fibers, fish rich in omega-3 fatty acids, and fruits rich in phytochemicals, for example. -this high- light begins with a look at some of these familiar functional foods, the phytochemicals they contain, and their roles in disease pre- s e g a m i y t t e g / x i p d o o f / y l l e k . -e n h o j vention. -then the discussion turns to examine the most controversial of functional foods novel foods to which phytochemicals have been added to promote health. -how these foods fit into a healthy diet is still unclear.2 the phytochemicals in foods, phytochemicals impart tastes, aromas, colors, and other characteristics. -they give hot peppers their burning sensation, garlic its pungent flavor, and tomatoes their dark red color. -in the body, phytochemicals can have profound physiological effects, acting as antioxidants, mimicking hormones, and suppressing the development of diseases.3 table h13-1 (p. 470) presents the names, possible effects, and food sources of some of the better- known phytochemicals. -defending against cancer a variety of phytochemicals from a variety of foods appear to pro- tect against dna damage and defend the body against cancer. -a few examples follow. -soybeans and products made from them correlate with low rates of some cancers.4 soybeans as well as other legumes, flaxseeds, whole grains, fruits, and vegetables are a rich source of an array of phytochemicals, among them the phytoestrogens. -because the chemical structure of these phytochemicals is similar to the steroid hormone estrogen, they can weakly mimic or modulate the effects of estrogen in the body.5 they also have antioxidant g lossary flavonoids (flay-von-oyds): yellow pigments in foods; phytochemicals that may exert physiological effects on the body. -flaxseeds: the small brown seeds of the flax plant; valued as a source of linseed oil, fiber, and omega-3 fatty acids. -lignans: phytochemicals present in flaxseed, but not in flax oil, that are converted to phytosterols by intestinal bacteria and are under study as possible anticancer agents. -phytoestrogens: plant-derived lutein (loo-teen): a plant pigment of yellow hue; a phytochemical believed to play roles in eye functioning and health. -lycopene (lye-koh-peen): a pigment responsible for the red color of tomatoes and other red-hued vegetables; a phytochemical that may act as an antioxidant in the body. -compounds that have structural and functional similarities to human estrogen. -phytoestrogens include the isoflavones genistein, daidzein, and glycitein. -phytosterols: plant-derived compounds that have structural similarities to cholesterol and lower blood cholesterol by competing with cholesterol for absorption. -phytosterols include sterol esters and stanol esters. -reminders: phytochemicals are nonnutrient compounds found in plant-derived foods that have biological activity in the body. -functional foods are foods that contain physiologically active compounds that provide health benefits beyond basic nutrition. -469 470 highlight 13 table h13-1 phytochemicals their food sources and actions name alkylresorcinolsa capsaicin possible effects may contribute to the protective effect of grains in reduc- ing the risks of diabetes, heart disease, and some cancers. -food sources whole grain wheat and rye modulates blood clotting, possibly reducing the risk of fatal clots in heart and artery disease. -hot peppers carotenoids (include beta- carotene, lycopene, lutein, and hundreds of related compounds)b act as antioxidants, possibly reducing risks of cancer and other diseases. -deeply pigmented fruits and vegetables (apricots, broccoli, cantaloupe, carrots, pumpkin, spinach, sweet potatoes, tomatoes) curcumin may inhibit enzymes that activate carcinogens. -tumeric, a yellow-colored spice flavonoids (include flavones, flavonols, isoflavones, catechins, and others)a,c act as antioxidants; scavenge carcinogens; bind to nitrates in the stomach, preventing conversion to nitrosamines; inhibit cell proliferation. -berries, black tea, celery, citrus fruits, green tea, olives, onions, oregano, purple grapes, purple grape juice, soy- beans and soy products, vegetables, whole wheat, wine indolesd may trigger production of enzymes that block dna damage from carcinogens; may inhibit estrogen action. -isothiocyanates (including sulforaphane) inhibit enzymes that activate carcinogens; trigger pro- duction of enzymes that detoxify carcinogens. -broccoli and other cruciferous vegetables (brussels sprouts, cabbage, cauliflower), horseradish, mustard greens broccoli and other cruciferous vegetables (brussels sprouts, cabbage, cauliflower), horseradish, mustard greens lignanse block estrogen activity in cells, possibly reducing the risk of cancer of the breast, colon, ovaries, and prostate. -flaxseed and its oil, whole grains monoterpenes (include limonene) may trigger enzyme production to detoxify carcinogens; inhibit cancer promotion and cell proliferation. -citrus fruit peels and oils organosulfur compounds may speed production of carcinogen-destroying enzymes; slow production of carcinogen-activating enzymes. -chives, garlic, leeks, onions phenolic acidsa phytic acid phytoestrogens (genistein and daidzein) protease inhibitors resveratrol saponins tanninsa may trigger enzyme production to make carcinogens water soluble, facilitating excretion. -coffee beans, fruits (apples, blueberries, cherries, grapes, oranges, pears, prunes), oats, potatoes, soybeans binds to minerals, preventing free-radical formation, possibly reducing cancer risk. -whole grains estrogen inhibition may produce these actions: inhibit cell replication in gi tract; reduce risk of breast, colon, ovarian, prostate, and other estrogen-sensitive cancers; reduce cancer cell survival. -estrogen mimicking may reduce risk of osteoporosis. -may suppress enzyme production in cancer cells, slowing tumor growth; inhibit hormone binding; inhibit malignant changes in cells. -soybeans, soy flour, soy milk, tofu, textured vegetable protein, other legume products broccoli sprouts, potatoes, soybeans and other legumes, soy products offsets artery-damaging effects of high-fat diets. -red wine, peanuts may interfere with dna replication, preventing cancer cells from multiplying; stimulate immune response. -alfalfa sprouts, other sprouts, green vegetables, potatoes, tomatoes may inhibit carcinogen activation and cancer promotion; act as antioxidants. -black-eyed peas, grapes, lentils, red and white wine, tea aa subset of the larger group phenolic phytochemicals. -bother carotenoids include alpha-carotene, beta-cryptoxanthin, and zeaxanthin. -cother flavonoids of interest include ellagic acid and ferulic acid; see also phytoestrogens. -dindoles include dithiothiones, isothiocyantes, and others. -elignans act as phytosterols and phytoestrogens, but their food sources are limited. -activity that appears to slow the growth of breast and prostate cancers.6 however, the use of phytoestrogen supplements is ill- advised as they may stimulate the growth of estrogen-dependent cancers (such as breast cancer).7 even the role of soy foods for breast cancer survivors is uncertain. -soy foods may be most effec- tive when consumed in moderation throughout life. -the ameri- can cancer society recommends: breast cancer survivors should consume only moderate amounts of soy foods as part of a healthy plant-based diet and should not intentionally ingest very high lev- els of soy products. -8 tomatoes seem to offer protection against cancers of the esoph- agus, lungs, prostate, and stomach. -among the phytochemicals re- sponsible for this effect is lycopene, one of beta-carotene s many carotenoid relatives. -lycopene is the pigment that gives apricots, guava, papaya, pink grapefruits, and watermelon their red color and it is especially abundant in tomatoes and cooked tomato prod- ucts. -lycopene is a powerful antioxidant that seems to inhibit the growth of cancer cells.9 importantly, these benefits are seen when people eat foods containing lycopene.10 soybeans and tomatoes are only two of the many fruits and vegetables credited with providing anticancer activity. -strong and convincing evidence shows that the risk of many cancers, and perhaps of cancer in general, decreases when diets include an abundance of fruits and vegetables.11 to that end, current recom- mendations urge consumers to eat five to nine servings of fruits and vegetables a day. -defending against heart disease diets based primarily on unprocessed foods appear to support heart health better than those founded on highly refined foods perhaps because of the abundance of nutrients, fiber, or phytochemicals such as the flavonoids.12 flavonoids, a large group of phytochem- icals known for their health-promoting qualities, are found in whole grains, legumes, soy, vegetables, fruits, herbs, spices, teas, choco- late, nuts, olive oil, and red wines.13 flavonoids are powerful antiox- idants that may help to protect ldl cholesterol against oxidation and reduce blood platelet stickiness, making blood clots less likely.14 an abundance of flavonoid-containing foods in the diet lowers the risks of chronic diseases.15 importantly, no claims can be made for flavonoids themselves as the protective factor, particularly when they are extracted from foods and sold as supplements.16 in addition to flavonoids, fruits and vegetables are rich in carotenoids. -studies suggest that a diet rich in carotenoids is also associated with a lower risk of heart disease.17 notable among the carotenoids that may defend against heart disease are lutein and lycopene.18 the phytosterols of soybeans and the lignans of flaxseed may also protect against heart disease.19 these cholesterol-like molecules are naturally found in all plants and inhibit cholesterol absorption in the body. -as a result, blood cholesterol levels de- cline.20 these phytochemicals also seem to protect against heart disease by acting as antioxidants and lowering blood pressure.21 the phytochemicals in perspective because foods deliver thousands of phytochemicals in addition to dozens of nutrients, researchers must be careful in giving credit for particular health benefits to any one compound. -diets rich in whole grains, legumes, vegetables, fruits, and nuts seem to pro- tect against heart disease and cancer, but identifying the specific foods or components of foods that are responsible is difficult.22 each food possesses a unique array of phytochemicals citrus fruits provide monoterpenes; grapes, resveratrol; and flaxseed, lig- nans. -(review table h13-1 for the possible effects and other food sources of these phytochemicals.) -broccoli may contain as many as 10,000 different phytochemicals each with the potential to influ- e r o o m . -i m g a r c phytochemicals and functional foods 471 ence some action in the body. -beverages such as wine, spices such as oregano, and oils such as olive oil (especially virgin olive oil) contain many phytochemicals that may explain, in part, why peo- ple who live in the mediterranean region have reduced risks of heart disease and cancer.23 phytochemicals might also explain why the dash diet is so effective in lowering blood pressure and blood lipids.24 even identifying all of the phytochemicals and their effects doesn t answer all the questions because the actions of phytochemicals may be complementary or overlapping which reinforces the principle of variety in diet planning. -for an appreci- ation of the array of phytochemicals offered by a variety of fruits and vegetables, see figure h13-1 (p. 472). -functional foods because foods naturally contain thousands of phytochemicals that are biologically active in the body, virtually all of them have some special value in supporting health. -in other words, even simple, whole foods, in reality, are functional foods. -cranberries may help protect against urinary tract infections; garlic may lower blood cho- lesterol; and tomatoes may protect against some cancers, just to name a few examples.25 but that hasn t stopped food manufactur- ers from trying to create functional foods as well. -the creation of more functional foods has become the fastest-growing trend and the greatest influence transforming the american food supply.26 many processed foods become functional foods when they are fortified with nutrients or enhanced with phytochemicals or herbs (calcium-fortified orange juice, for example). -less frequently, an entirely new food is created, as in the case of a meat substitute made of mycoprotein a protein derived from a fungus. -*27 this functional food not only provides dietary fiber, polyunsaturated fats, and high-quality protein, but it lowers ldl cholesterol, raises hdl cholesterol, improves glucose response, and prolongs satiety after a meal. -such a novel functional food raises the question is it a food or a drug? -foods as pharmacy not too long ago, most of us could agree on what was a food and what was a drug. -today, functional foods blur the distinctions.28 they have characteristics similar to both foods and drugs, but do not fit neatly into either category. -consider margarine, for example. -eating nonhydrogenated margarine sparingly instead of but- ter generously may lower blood cholesterol slightly over several months and clearly falls into the food category. -taking the drug lipitor, on the other hand, lowers blood cholesterol significantly within weeks and clearly falls into the drug category. -but mar- garine enhanced with a phytosterol that lowers blood cholesterol is in a gray area between the two. -the margarine looks and tastes like a food, but it acts like a drug. -the use of functional foods as drugs creates a whole new set of diet-planning challenges. -not only must foods provide an adequate intake of all the nutrients to support good health, but they must nature offers a variety of functional foods that provide us with many health benefits. -* this mycoprotein product is marketed under the trade name quorn (pro- nounced kworn). -472 highlight 13 figure h13-1 an array of phytochemicals in a variety of fruits and vegetables o i g g u r r a f w e h t t a m , s e g a m i y t t e g / c s i d o t o h p , a d a n a c f o l i c n u o c x a l f f o y s e t r u o c , . -c n i , e r i w e y e , c s i d o t o h p 1 0 0 2 , s t c u d o r p n o i t c e t o r p a c i s s a r b f o y s e t r u o c broccoli and broccoli sprouts contain an abundance of the cancer-fighting phytochemical sulforaphane. -an apple a day rich in flavonoids may protect against lung cancer. -the phytoestrogens of soybeans seem to starve cancer cells and inhibit tumor growth; the phytosterols may lower blood cholesterol and protect garlic, with its abundant organosulfur compounds, may lower blood cholesterol and protect against stomach cancer. -the phytochemical resveratrol found in grapes (and nuts) protects against cancer by inhibiting cell growth and against heart disease by limiting clot formation and inflammation. -the ellagic acid of strawberries may inhibit certain types of cancer. -tomatoes, with their abundant lycopene, may defend against cancer by protecting dna from oxidative damage. -the monoterpenes of citrus fruits (and cherries) may inhibit cancer growth. -the flavonoids in black tea may protect against heart disease, whereas those in green tea may defend against cancer. -the flavonoids in cocoa and chocolate defend against oxidation and reduce the tendency of blood to clot. -spinach and other colorful vegetables contain the carotenoids lutein and zeaxanthin, which help protect the eyes against macular degeneration. -flaxseed, the richest source of lignans, may prevent the spread of cancer. -blueberries, a rich source of flavonoids, improve memory in animals. -also deliver drug-like ingredients to protect against disease. -like drugs used to treat chronic diseases, functional foods may need to be eaten several times a day for several months or years to have a beneficial effect. -sporadic users may be disappointed in the re- sults. -margarine enriched with 2 to 3 grams of phytosterols may reduce cholesterol by up to 15 percent, much more than regular margarine does, but not nearly as much as the more than 30 per- cent reduction seen with cholesterol-lowering drugs.29 for this reason, functional foods may be more useful for prevention and mild cases of disease than for intervention and more severe cases. -foods and drugs differ dramatically in cost as well. -functional foods such as fruits and vegetables incur no added costs, of course, but foods that have been manufactured with added phy- tochemicals can be expensive, costing up to six times as much as their conventional counterparts. -the price of functional foods typically falls between that of traditional foods and medicines. -unanswered questions to achieve a desired health effect, which is the better choice: to eat a food designed to affect some body function or simply to ad- just the diet? -does it make more sense to use a margarine en- hanced with a phytosterol that lowers blood cholesterol or simply to limit the amount of butter eaten? -* is it smarter to eat eggs en- riched with omega-3 fatty acids or to restrict egg consumption? -* margarine products that lower blood cholesterol contain either sterol esters from vegetable oils, soybeans, and corn or stanol esters from wood pulp. -might functional foods offer a sensible solution for improving our nation s health if done correctly? -perhaps so, but the problem is that the food industry is moving too fast for either scientists or the food and drug administration to keep up. -consumers were able to buy soup with st. john s wort that claimed to enhance mood and fruit juice with echinacea that was supposed to fight colds while sci- entists were still conducting their studies on these ingredients. -re- search to determine the safety and effectiveness of these substances is still in progress. -until this work is complete, consumers are on their own in finding the answers to the following questions: does it work? -research is generally lacking and findings are often inconclusive. -how much does it contain? -food labels are not required to list the quantities of added phytochemicals. -even if they were, con- sumers have no standard for comparison and cannot deduce whether the amounts listed are a little or a lot. -most impor- tantly, until research is complete, food manufacturers do not know what amounts (if any) are most effective or most toxic. -is it safe? -functional foods can act like drugs. -they contain ingredients that can alter body functions and cause allergies, drug interactions, drowsiness, and other side effects. -yet, unlike drug labels, food labels do not provide instructions for the dosage, frequency, or duration of treatment. -is it healthy? -adding phytochemicals to a food does not magi- cally make it a healthy choice. -a candy bar may be fortified with phytochemicals, but it is still made mostly of sugar and fat. -critics suggest that the designation functional foods may be nothing more than a marketing tool. -after all, even the most expe- rienced researchers cannot yet identify the perfect combination of nutrients and phytochemicals to support optimal health. -yet manu- facturers are freely experimenting with various concoctions as if they possessed that knowledge. -is it okay for them to sprinkle phyto- chemicals on fried snack foods or caramel candies and label them functional, thus implying health benefits? -future foods nature has elegantly designed foods to provide us with a com- plex array of dozens of nutrients and thousands of additional phytochemicals and functional foods 473 functional foods currently on the market promise to enhance mood, promote relaxation and good karma, increase alert- ness, and improve memory, among other claims. -e r o o m . -m g i a r c compounds that may benefit health most of which we have yet to identify or understand. -over the years, we have taken those foods, deconstructed them, and then reconstructed them in an effort to improve them. -with new scientific understand- ings of how nutrients and the myriad other compounds in foods interact with genes, we may someday be able to design foods to meet the exact health needs of each individual.30 in- deed, our knowledge of the human genome and of human nu- trition may well merge to allow specific recommendations for individuals based on their predisposition to diet-related diseases. -if the present trend continues, someday physicians may be able to prescribe the perfect foods to enhance your health, and farmers will be able to grow them. -as highlight 19 explains, sci- entists have already developed gene technology to alter the composition of food crops. -they can grow rice enriched with vi- tamin a and tomatoes containing a hepatitis vaccine, for exam- ple. -it seems quite likely that foods can be created to meet every possible human need. -but then, in a sense, that was largely true 100 years ago when we relied on the bounty of nature. -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 13, then to highlights nutrition on the net. -search for functional foods at the center for science in the public interest: www.cspinet.org find out if warnings have been issued for any food ingre- search for functional foods at the international food dients at the fda website: www.fda.gov information council: www.ific.org 474 highlight 13 references 1. position of the american dietetic associa- tion: functional foods, journal of the ameri- can dietetic association 104 (2004): 814-826. -2. c. h. halsted, dietary supplements and functional foods: 2 sides of a coin? -american journal of clinical nutrition 77 (2003): 1001s- 1007s. -3. c. manach and coauthors, polyphenols: food sources and bioavailability, american journal of clinical nutrition 79 (2004): 727- 747; p. m. kris-etherton and coauthors, bioactive compounds in foods: their role in the prevention of cardiovascular disease and cancer, american journal of medicine 113 (2002): 71s-88s. -4. m. b. schabath and coauthors, dietary phytoestrogens and lung cancer risk, journal of the american medical association 294 (2005): 1493-1504; w. h. xu and coauthors, soya food intake and risk of endometrial cancer among chinese women in shanghai: population based case-control study, british medical journal 328 (2004): 1285-1288. -5. i. c. munro and coauthors, soy isoflavones: a safety review, nutrition reviews 61 (2003): 1-33. -6. t. a. ryan-borchers and coauthors, soy isoflavones modulate immune function in healthy postmenopausal women, american journal of clinical nutrition 83 (2006): 1118- 1125; c. a. lamartiniere and coauthors, genistein chemoprevention: timing and mechanisms of action in murine mammary and prostate, journal of nutrition 132 (2002): 552s-558s. -7. m. messina, w. mccaskill-stevens, j. w. lampe, addressing the soy and breast can- cer relationship: review, commentary, and workshop proceedings, journal of the na- tional cancer institute 98 (2006): 1275-1284. -8. g. maskarinec, soy foods for breast cancer survivors and women at high risk for breast cancer? -journal of the american dietetic association 105 (2005): 1524-1528. -9. a. basu and v. imrhan, tomatoes versus lycopene in oxidative stress and carcinogen- esis: conclusions from clinical trials, euro- pean journal of clinical nutrition (2006); d. heber and q. y. lu, overview of mecha- nisms of action of lycopene, experimental biology and medicine 227 (2002): 920-923; t. m. vogt and coauthors, serum lycopene, other serum carotenoids, and risk of prostate cancer in us blacks and whites, american journal of epidemiology 155 (2002): 1023-1032. -10. s. ellinger, j. ellinger, and p. stehle, toma- toes, tomato products and lycopene in the prevention and treatment of prostate can- cer: do we have the evidence from interven- tion studies? -current opinion in clinical nutrition and metabolic care 9 (2006): 722- 727; e. giovannucci and coauthors, a prospective study of tomato products, lycopene, and prostate cancer risk, journal of the national cancer institute 94 (2002): 391-398. -11. c. a. gonzalez, nutrition and cancer: the current epidemiological evidence, british journal of nutrition 96 (2006): s42-s45; h. vainio and e. weiderpass, fruit and vegeta- bles in cancer prevention, nutrition and cancer 54 (2006): 111-142. -12. j. a. ross and c. m. kasum, dietary flavonoids: bioavailability, metabolic effects, and safety, annual review of nutrition 22 (2002): 19-34. -13. m. b. engler and m. m. engler, the emerg- ing role of flavonoid-rich cocoa and choco- late in cardiovascular health and disease, nutrition reviews 64 (2006): 109-118; m. w. ariefdjohan and d. a. savaiano, chocolate and cardiovascular health: is it too good to be true? -nutrition reviews 63 (2005): 427- 430; f. m. steinberg, m. m. bearden, and c. l. keen, cocoa and chocolate flavonoids: implications for cardiovascular health, journal of the american dietetic association 103 (2003): 215-223; f. visioli and c. galli, biological properties of olive oil phytochem- icals, critical reviews in food science and nutrition 42 (2002): 209-221; y. j. surh, anti-tumor promoting potential of selected spice ingredients with antioxidative and anti-inflammatory activities: a short review, food and chemical toxicology 40 (2002): 1091-1097; j. m. geleijnse and coauthors, inverse association of tea and flavonoid intakes with incident myocardial infarction: the rotterdam study, american journal of clinical nutrition 75 (2002): 880-886. -15. m. messina, c. gardner, and s. barnes, gaining insight into the health effects of soy but a long way still to go: commentary on the fourth international symposium on the role of soy in preventing and treating chronic disease, journal of nutrition 132 (2002): 547s-551s; p. knekt and coauthors, flavonoid intake and risk of chronic dis- eases, american journal of clinical nutrition 76 (2002): 560-568. -16. ross and kasum, 2002. -17. s. k. osganian and coauthors, dietary carotenoids and risk of coronary artery disease in women, american journal of clini- cal nutrition 77 (2003): 1390-1399; s. liu and coauthors, intake of vegetables rich in carotenoids and risk of coronary heart disease in men: the physicians heart study, international journal of epidemiology 30 (2001): 130-135. -18. t. h. rissanen and coauthors, serum ly- copene concentrations and carotid athero- sclerosis: the kuopio ischaemic heart disease risk factor study, american journal of clinical nutrition 77 (2003): 133-138; heber and lu, 2002. -19. l. t. bloedon and p. o. szapary, flaxseed and cardiovascular risk, nutrition reviews 62 (2004): 18-27; x. zhang and coauthors, soy food consumption is associated with lower risk of coronary heart disease in chinese women, journal of nutrition 133 (2003): 2874-2878; r. e. ostlund, jr., phytosterols in human nutrition, annual review of nutrition 22 (2002): 533-549. -20. v. w. y. lau, m. journoud, and p. j. h. jones, plant sterols are efficacious in lower- ing plasma ldl and non-hdl cholesterol in hypercholesterolemic type 2 diabetic and nondiabetic persons, american journal of clinical nutrition 81 (2005): 1351-1358; s. zhan and s. c. ho, meta-analysis of the effects of soy protein containing isoflavones on the lipid profile, american journal of clinical nutrition 81 (2005): 397-408; e. a. lucas and coauthors, flaxseed improves lipid profile without altering biomarkers of bone metabolism in postmenopausal women, journal of clinical endocrinology and metabolism 87 (2002): 1527-1532; c. a. vanstone and coauthors, unesterified plant sterols and stanols lower ldl-cholesterol concentrations equivalently in hypercholes- terolemic persons, american journal of clini- cal nutrition 76 (2002): 1272-1278. -21. l. t. bloedon and p. o. szapary, flaxseed and cardiovascular risk, nutrition reviews 62 (2004): 18-27; m. rivas and coauthors, soy milk lowers blood pressure in men and women with mild to moderate essential hypertension, journal of nutrition 132 (2002): 1900-1902. -23. m. i. covas and coauthors, the effect of polyphenols in olive oil on heart disease risk factors: a randomized trial, annals of inter- nal medicine 145 (2006): 333-341; y. z. h-y. -hashim and coauthors, components of olive oil and chemoprevention of colorectal cancer, nutrition reviews 63 (2005): 374-386; f. visioli, a. poli, and c. gall, antioxidant and other biological activities of phenols from olives and olive oil, medicinal research reviews 22 (2002): 65-75. -24. m. m. most, estimated phytochemical content of the dietary approaches to stop hypertension (dash) diet is higher than in the control study diet, journal of the ameri- can dietetic association 104 (2004): 1725-1727. -25. a. b. howell and b. foxman, cranberry juice and adhesion of antibiotic resistant uropathogens, journal of the american med- ical association 287 (2002): 3082-3083; c. w. hadley and coauthors, tomatoes, lycopene, and prostate cancer: progress and promise, experimental biology and medicine 227 (2002): 869-880. -26. position of the american dietetic associa- tion, 2004. -27. t. peregrin, mycoprotein: is america ready for a meat substitute derived from a fungus? -journal of the american dietetic association 102 (2002): 628. -28. c. l. taylor, regulatory frameworks for functional foods and dietary supplements, nutrition reviews 62 (2004): 55-59. -29. c. s. patch, l. c. tapsell, and p. g. williams, plant sterol/stanol prescription is an effec- tive treatment strategy for managing hyper- cholesterolemia in outpatient clinical practice, journal of the american dietetic association 105 (2005): 46-52; d. a. j. m. kerckhoffs and coauthors, effects on the human serum lipoprotein profile of - glucan, soy protein and isoflavones, plant sterols and stanols, garlic and tocotrienols, journal of nutrition 132 (2002): 2494-2505; l. a. simons, additive effect of plant sterol- ester margarine and cerivastatin in lowering low-density lipoprotein cholesterol in pri- mary hypercholesterolemia, american jour- nal of cardiology 90 (2002): 737-740. -30. j. a. milner, functional foods and health: a us perspective, british journal of nutrition 88 (2002): s151-158. -this page intentionally left blank tony generico/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow figure 14-2: animated! -delivery of oxygen by the heart and lungs to the muscles nutrition portfolio journal nutrition in your life you choose to be physically active or inactive, and your choice can make a huge difference in how well you feel and how long you live. -today s world makes it easy to be inactive too easy in fact but the many health rewards of being physically active make it well worth the effort. -you may even discover how much fun it is to be active, and with a little perseverance, you may become physically fit as well. -as you become more active, you will find that the foods you eat can make a difference in how fast you run, how far you swim, or how much weight you lift. -it s up to you. -the choice is yours. -fitness: physical activity, nutrients, and body adaptations are you physically fit? -if so, the following description applies to you. -your joints are flexible, your muscles are strong, and your body is lean with enough, but not too much, fat. -you have the endurance to engage in daily physical activities with enough reserve energy to handle added challenges. -carrying heavy suitcases, opening a stuck window, or climbing four flights of stairs, which might strain an unfit person, is easy for you. -what s more, you are prepared to meet mental and emotional challenges, too. -all these characteristics of fitness describe the same wonderful condition of a healthy body. -or perhaps you are leading a sedentary life. -today s world encourages inactivity, and people who go through life exerting minimal physical ef- fort, become weak and unfit and may begin to feel unwell. -in fact, a seden- tary lifestyle fosters the development of several chronic diseases. -regardless of your level of fitness, this chapter is written for you, who- ever you are and whatever your goals whether you want to improve your health, lose weight, hone your athletic skills, ensure your position on a sports team, or simply adopt an active lifestyle. -this chapter begins by dis- cussing fitness and its benefits and then goes on to explain how the body uses energy nutrients to fuel physical activity. -finally, it describes diets to support fitness. -fitness fitness depends on a certain minimum amount of physical activity or exer- cise. -both physical activity and exercise involve body movement, muscle contrac- tion, and enhanced energy expenditure, but a distinction is made between the two terms. -exercise is often considered to be vigorous, structured, and planned physi- cal activity. -this chapter focuses on how the active body uses energy nutrients whether that body is pedaling a bike across campus or pedaling a stationary bike in a gym. -thus, for our purposes, the terms physical activity and exercise are used interchangeably. -c h a p t e r 14 chapter outline fitness benefits of fitness develop- ing fitness cardiorespiratory endurance weight training energy systems, fuels, and nutri- ents to support activity the energy systems of physical activity atp and cp glucose use during physical activity fat use during physical activity protein use during physical activity and between times vitamins and minerals to support activity fluids and electrolytes to support activity poor beverage choices: caffeine and alcohol diets for physically active people choosing a diet to support fitness meals before and after competition highlight 14 supplements as ergogenic aids fitness: the characteristics that enable the body to perform physical activity; more broadly, the ability to meet routine physical demands with enough reserve energy to rise to a physical challenge; or the body s ability to withstand stress of all kinds. -sedentary: physically inactive (literally, sitting down a lot ). -physical activity: bodily movement produced by muscle contractions that substantially increase energy expenditure. -exercise: planned, structured, and repetitive body movements that promote or maintain physical fitness. -477 478 chapter 14 physical activity, or its lack, exerts a significant and pervasive influence on everyone s nutri- tion and overall health. -each comparison influences the risks asso- ciated with chronic disease and death similarly: vigorous exercise vs. minimal exercise healthy weight vs. 20% overweight nonsmoking vs. smoking (one pack a day) e l i f r e t s a m / h c i l i m n a r o z benefits of fitness extensive evidence confirms that regular physical activity promotes health and reduces the risk of developing a number of diseases.1 still, despite an increasing awareness of the health benefits that physical activity confers, more than half of adults in the united states are not regularly active, and 25 percent are completely inactive.2 physical inactivity is linked to the major degenerative diseases heart dis- ease, cancer, stroke, diabetes, and hypertension the primary killers of adults in de- veloped countries.3 every year an estimated $77 billion is spent on health care costs attributed to physical inactivity in the united states.4 as a person becomes physically fit, the health of the entire body improves. -in general, physically fit people enjoy: restful sleep. -rest and sleep occur naturally after periods of physical activity. -during rest, the body repairs injuries, disposes of wastes generated during ac- tivity, and builds new physical structures. -nutritional health. -physical activity expends energy and thus allows people to eat more food. -if they choose wisely, active people will consume more nutri- ents and be less likely to develop nutrient deficiencies. -optimal body composition. -a balanced program of physical activity limits body fat and increases or maintains lean tissue. -thus physically active peo- ple have relatively less body fat than sedentary people at the same body weight.5 optimal bone density. -weight-bearing physical activity builds bone strength and protects against osteoporosis.6 resistance to colds and other infectious diseases. -fitness enhances immunity. -*7 low risks of some types of cancers. -lifelong physical activity may help to pro- tect against colon cancer, breast cancer, and some other cancers.8 strong circulation and lung function. -physical activity that challenges the heart and lungs strengthens the circulatory system. -low risk of cardiovascular disease. -physical activity lowers blood pressure, slows resting pulse rate, and lowers blood cholesterol, thus reducing the risks of heart attacks and strokes.9 some research suggests that physical activity may reduce the risk of cardiovascular disease in another way as well by re- ducing intra-abdominal fat stores.10 low risk of type 2 diabetes. -physical activity normalizes glucose tolerance.11 regular physical activity reduces the risk of developing type 2 diabetes and benefits those who already have the condition. -reduced risk of gallbladder disease in women. -regular physical activity reduces women s risk of gallbladder disease perhaps by facilitating weight control and lowering blood lipid levels.12 low incidence and severity of anxiety and depression. -physical activity may im- prove mood and enhance the quality of life by reducing depression and anxiety.13 strong self-image. -the sense of achievement that comes from meeting physi- cal challenges promotes self-confidence. -long life and high quality of life in the later years. -active people have a lower mortality rate than sedentary people.14 even a two-mile walk daily can add years to a person s life. -in addition to extending longevity, physical activity supports independence and mobility in later life by reducing the risk of falls and minimizing the risk of injury should a fall occur.15 * moderate physical activity can stimulate immune function. -intense, vigorous, prolonged activity such as marathon running, however, may compromise immune function. -fitness: physical activity, nutrients, and body adaptations 479 dietary guidelines for americans 2005 engage in regular physical activity and reduce sedentary activities to pro- mote health, psychological well-being, and a healthy body weight. -what does a person have to do to reap the health rewards of physical activ- ity? -the dietary guidelines for americans 2005 specify that, for health s sake, peo- ple need to spend an accumulated minimum of 30 minutes in some sort of physical activity on most days of each week.16 eight minutes spent climbing up stairs, another 10 spent pulling weeds, and 12 more spent walking the dog all contribute to the day s total (see figure 14-1). -both the dietary guidelines 2005 and the dri committee, however, advise that 30 minutes of physical activity each day is not enough for adults to maintain a healthy body weight (bmi of 18.5 to 24.9) and recommend at least 60 minutes of moderately intense activity such as walking or jogging each day.17 the hour or more of activity can be split into shorter sessions throughout the day two 30-minute sessions, or four 15- minute sessions, for example.18 to develop and maintain fitness, the american college of sports medicine (acsm) recommends the types and amounts of physical activities presented in table 14-1 (p. 480).19 following these guidelines will help adults improve their car- diorespiratory endurance, body composition, strength, and flexibility. -at this level of fitness, a person can reap even greater health benefits (further reduction of cardiovascular disease risk, for example).20 the bottom line is that any physical activity, even moderate activity, provides some health benefits, and these benefits follow a dose-response relationship. -figure 14-1 physical activity pyramid reminder: body composition refers to the proportions of muscle, bone, fat, and other tissue that make up a person s total body weight. -do seldom limit sedentary activities. -(cid:129) watch tv or movies (cid:129) leisure computer time 2 3 days/week engage in strength and flexibility activities and enjoy leisure activities often. -(cid:129) sit-ups, push-ups (cid:129) strength training such as weight lifting (cid:129) stretching exercises such as yoga (cid:129) leisure activities such as canoeing, dancing, golfing, horseback riding, bowling 4 6 days/week engage in moderate or vigorous activities regularly. -(cid:129) aerobic activities such as running, biking, swimming, roller-blading, rowing, cross-country skiing, kickboxing, power walking, dancing, jumping rope (cid:129) sports activities such as basketball, soccer, volleyball, tennis, football, racquetball, softball every day be as active as possible. -(cid:129) use the stairs (cid:129) walk or bike to class, work, or shops (cid:129) scrub floors, wash windows (cid:129) walk your dog (cid:129) mow grass, rake leaves, turn compost, shovel snow,tend garden (cid:129) wash and wax your car (cid:129) play with children s i b r o c / s e g a m i n o s t a w e k i m y m a l a / t t i h y e l s e w y t t e g / t t a b s i u o l n a e j s e g a m i y t t e g / l l e w o p e k i m s e g a m i note: tips for increasing physical activity every day can be found at mypyramid.gov. -480 chapter 14 table 14-1 guidelines for physical fitness cardiorespiratory strength flexibility s e g a m i y t t e g / c s i d o t o h p y h p a r g o t o h p r e v o n a h d i v a d y h p a r g o t o h p r e v o n a h d i v a d aerobic activity that uses large- muscle groups and can be main- tained continuously resistance activity that is performed at a controlled speed and through a full range of motion stretching activity that uses the major muscle groups 3 to 5 days per week 2 to 3 days per week 2 to 7 days per week 55 to 90% of maximum heart rate enough to enhance muscle strength and improve body composition enough to develop and maintain a full range of motion 20 to 60 minutes 8 to 12 repetitions of 8 to 10 different exercises (minimum) 2 to 4 repetitions of 15 to 30 seconds per muscle group running, cycling, swimming, inline skating, rowing, power walking, cross-country skiing, kickboxing, jumping rope; sports activities such as basketball, soccer, raquetball, tennis, volleyball pull-ups, push-ups, weight lifting, pilates yoga type of activity frequency intensity duration examples source: adapted from american college of sports medicine, general principles of exercise prescription, in acsm s guidelines for exercise testing and prescription, 7th ed. -(philadelphia, pa: lippincott williams & wilkins, 2006), pp.133 173. flexibility: the capacity of the joints to move through a full range of motion; the ability to bend and recover without injury. -muscle strength: the ability of muscles to work against resistance. -muscle endurance: the ability of a muscle to contract repeatedly without becoming exhausted. -cardiorespiratory endurance: the ability to perform large-muscle, dynamic exercise of moderate-to-high intensity for prolonged periods. -conditioning: the physical effect of training; improved flexibility, strength, and endurance. -training: practicing an activity regularly, which leads to conditioning. -(training is what you do; conditioning is what you get.) -progressive overload principle: the training principle that a body system, in order to improve, must be worked at frequencies, durations, or intensities that gradually increase physical demands. -frequency: the number of occurrences per unit of time (for example, the number of activity sessions per week). -intensity: the degree of exertion while exercising (for example, the amount of weight lifted or the speed of running). -duration: length of time (for example, the time spent in each activity session). -therefore, some activity is better than none, and more activity is better still up to a point. -(pursued in excess, intense physical activity, especially when combined with poor eating habits, can undermine health, as highlight 8 explained.) -developing fitness to be physically fit, a person must develop enough flexibility, muscle strength and en- durance, and cardiorespiratory endurance to meet the everyday demands of life with some to spare and to achieve a reasonable body weight and body composition. -flex- ibility allows the joints to move freely, reducing the risk of injury. -muscle strength and muscle endurance enable muscles to work harder and longer without fatigue. -cardiorespiratory endurance supports the ongoing activity of the heart and lungs. -physical activity supports lean body tissues and reduces excess body fat. -a per- son who practices a physical activity adapts by becoming better able to perform that activity after each session with more flexibility, more strength, and more endurance. -the principles of conditioning apply to each component of fitness flexibility, strength, and endurance. -during conditioning, the body adapts microscopically to perform the work it is asked to do. -the way to achieve conditioning is by training, primarily by applying the progressive overload principle that is, by asking a little more of the body in each training session. -the overload principle you can apply the progressive overload principle in several different ways. -you can perform the activity more often that is, increase its fre- quency. -you can perform it more strenuously that is, increase its intensity. -or you can do it for longer times that is, increase its duration. -all three strategies, individu- ally or in combination, work well. -the rate of progression depends on individual char- acteristics such as fitness level, health status, age, and preference. -if you enjoy your workout, do it more often. -if you do not have much time, increase intensity. -if you dis- like hard work, take it easy, and do it for longer time periods. -if you want continuous im- provements, remember to overload progressively as you reach higher levels of fitness. -fitness: physical activity, nutrients, and body adaptations 481 when increasing the frequency, intensity, or duration of a workout, however, ex- ercise to a point that only slightly exceeds the comfortable capacity to work. -it is bet- ter to progress slowly than to risk injury by overexertion. -the body s response to physical activity fitness develops in response to de- mand and wanes when demand ceases. -muscles gain size and strength after being made to work repeatedly, a response called hypertrophy. -conversely, without ac- tivity, muscles diminish in size and lose strength, a response called atrophy. -hypertrophy and atrophy are adaptive responses to the muscles greater and lesser work demands, respectively. -thus cyclists often have strong, well-developed legs but less arm or chest strength; a tennis player may have one superbly strong arm, while the other is just average. -a variety of physical activities produces the best overall fit- ness, and to this end, people need to work different muscle groups from day to day. -this strategy provides a day or two of rest for different muscle groups, giving them time to replenish nutrients and to repair any minor damage incurred by the activity. -other tips for building fitness and minimizing the risk of overuse injuries are: be active all week, not just on the weekends. -use proper equipment and attire. -perform exercises using proper form. -include warm-up and cool-down activities in each session. -warming up helps to prepare muscles, ligaments, and tendons for the upcoming activity and mobilizes fuels to support strength and endurance activities. -cooling down reduces muscle cramping and allows the heart rate to slow gradually. -train hard enough to challenge your strength or endurance a few times each week rather than every time you work out. -between challenges, do moderate workouts and include at least one day of rest each week. -pay attention to body signals. -symptoms such as abnormal heartbeats, dizzi- ness, lightheadedness, cold sweat, confusion, or pain or pressure in the middle of the chest, teeth, jaw, neck, or arm demand immediate medical attention. -work out wisely. -do not start with activities so demanding that pain stops you within a day or two. -learn to enjoy small steps toward improvement. -fitness builds slowly. -cautions on starting a fitness program before beginning a fitness program, make sure it is safe for you to do so. -most apparently healthy people can begin a moderate exercise program such as walking or increasing daily activities without a medical examination, but people with any of the risk factors listed in the margin may need medical advice.21 s e g a m i y t t e g / c s i d o t o h p / y a v c m n a y r s e g a m i y t t e g / e n o t s / n o s i d a m d i v a d people s bodies are shaped by the activities they perform. -s i b r o c / h c s r o m y o r physical activity helps you look good, feel good, and have fun, and it brings many long- term health benefits as well. -major coronary risk factors: family history of heart disease cigarette smoking hypertension serum cholesterol (cid:2)200 mg/dl or hdl (cid:3)40 mg/dl, or taking lipid- lowering medication diabetes sedentary lifestyle obesity (bmi (cid:4)30) hypertrophy (high-per-tro-fee): growing larger; with regard to muscles, an increase in size (and strength) in response to use. -atrophy (at-ro-fee): becoming smaller; with regard to muscles, a decrease in size (and strength) because of disuse, undernutrition, or wasting diseases. -warm-up: 5 to 10 minutes of light activity, such as easy jogging or cycling, prior to a workout to prepare the body for more vigorous activity. -cool-down: 5 to 10 minutes of light activity, such as walking or stretching, following a vigorous workout to gradually return the body s core to near-normal temperature. -moderate exercise: activity equivalent to the rate of exertion reached when walking at a speed of 4 miles per hour (15 minutes to walk one mile). -482 chapter 14 the key to regular physical activity is finding an activity that you enjoy. -recall from chapter 7 that aerobic means requiring oxygen. -cardiorespiratory conditioning: increases cardiac output and oxygen delivery increases stroke volume slows resting pulse increases breathing efficiency improves circulation reduces blood pressure vo2max: the maximum rate of oxygen consumption by an individual at sea level. -cardiorespiratory conditioning: improvements in heart and lung function and increased blood volume, brought about by aerobic training. -cardiac output: the volume of blood discharged by the heart each minute; determined by multiplying the stroke volume by the heart rate. -the stroke volume is the amount of oxygenated blood the heart ejects toward the tissues at each beat. -cardiac output (volume/minute) = stroke volume (volume/beat) (cid:5) heart rate (beats/minute) s i b r o c / e c r u o s e g a m i cardiorespiratory endurance the length of time a person can remain active with an elevated heart rate that is, the ability of the heart, lungs, and blood to sustain a given demand defines a per- son s cardiorespiratory endurance. -cardiorespiratory endurance training improves a person s ability to sustain vigorous activities such as running, brisk walking, or swimming. -such training enhances the capacity of the heart, lungs, and blood to de- liver oxygen to, and remove waste from, the body s cells. -cardiorespiratory en- durance training, therefore, is aerobic. -as the cardiorespiratory system gradually adapts to the demands of aerobic activity, the body delivers oxygen more efficiently. -in fact, the accepted measure of a person s cardiorespiratory fitness is maximal oxy- gen uptake (vo2max). -the benefits of cardiorespiratory training are not just phys- ical, though, because all of the body s cells, including the brain cells, require oxygen to function. -when the cells receive more oxygen more readily, both the body and the mind benefit. -cardiorespiratory conditioning cardiorespiratory conditioning occurs as aerobic workouts improve heart and lung activities. -cardiac output increases, thus enhancing oxygen delivery.22 the heart becomes stronger, and each beat pumps more blood. -because the heart pumps more blood with each beat, fewer beats are necessary, and the resting heart rate slows down. -the average resting pulse rate for adults is around 70 beats per minute, but people who achieve cardiorespira- tory conditioning may have resting pulse rates of 50 or even lower. -the muscles that work the lungs become stronger, too, so breathing becomes more efficient. -circula- tion through the arteries and veins improves. -blood moves easily, and blood pres- sure falls.23 cardiorespiratory endurance reflects the health of the heart and circulatory sys- tem, on which all other body systems depend. -figure 14-2 shows the major relation- ships among the heart, circulatory system, and lungs. -to improve your cardiorespiratory endurance, the activity you choose must be sustained for 20 minutes or longer and use most of the large-muscle groups of the body (legs, buttocks, and abdomen). -you must also train at an intensity that ele- vates your heart rate. -a person s own perceived effort is usually a reliable indicator of the intensity of an activity. -in general, when you re working out, do so at an intensity that raises your heart rate but still leaves you able to talk comfortably. -if you are more com- petitive and want to work to your limit on some days, a treadmill test can reveal your maximum heart rate. -you can work out safely at up to 90 percent of that rate. -the acsm guidelines for developing and maintaining cardiorespiratory fitness are given in table 14-1 on p. 480. muscle conditioning one of the benefits of cardiorespiratory training is that fit muscles use oxygen efficiently, reducing the heart s workload. -an added bonus is that muscles that use oxygen efficiently can burn fat longer a plus for body com- position and weight control. -a balanced fitness program the intensity and type of physical activities that are best for one person may not be good for another. -the intensity to choose depends on your present fitness: work hard enough to breathe heavily, but not so hard as to incur an oxygen debt. -a person who has been sedentary will initially perform at a dramatically different level of intensity than a fit person. -the type of physical activity that is best for you depends, too, on what you want to achieve and what you enjoy doing. -some people love walking, whereas others prefer to dance or ride a bike. -if you want to be stronger and firmer, lift weights. -and remember, muscle is more metabolically active than body fat, so the more muscle you have, the more energy you ll burn. -in a balanced fitness program, aerobic activity improves cardiorespiratory fit- ness, stretching enhances flexibility, and weight training develops muscle strength and endurance. -table 14-2 provides an example of a balanced fitness program. -fitness: physical activity, nutrients, and body adaptations 483 figure 14-2 animated! -delivery of oxygen by the heart and lungs to the muscles to test your understanding of these concepts, log on to www.thomsonedu.com/thomsonnow. -the cardiorespiratory system responds to the muscles demand for oxygen by building up its capacity to deliver oxygen. -researchers can measure cardiorespira- tory fitness by measuring the maximum amount of oxygen a person consumes per minute while working out, a measure called vo2max. -air (o2, co2), other gases 1 the respiratory system delivers oxygen to the blood. -o2 co2 co2 o2 co2 o2 o2 co2 4 the blood carries the carbon dioxide back to the lungs. -2 the circulatory system carries oxygenated blood throughout the body. -3 the muscles and other tissues obtain oxygen from the blood and release carbon dioxide into it. -dietary guidelines for americans 2005 achieve physical fitness by including cardiovascular conditioning, stretch- ing exercises for flexibility, and resistance exercises or calisthenics for mus- cle strength and endurance. -in summary physical activity brings positive rewards: good health and long life. -to develop fitness whose components are flexibility, muscle strength and endurance, and cardiorespiratory endurance a person must condition the body, through training, to adapt to the activity performed. -table 14-2 fitness program a sample balanced monday, tuesday, wednesday, thursday, friday: 5 minutes of warm-up activity 45 minutes of aerobic activity 10 minutes of cool-down activity and stretching tuesday, thursday, saturday: 5 minutes of warm-up activity 30 minutes of weight training 10 minutes of cool-down activity and stretching saturday and/or sunday: sports, walking, hiking, biking, or swimming 484 chapter 14 weight training (also called resistance training): the use of free weights or weight machines to provide resistance for developing muscle strength and endurance. -a person s own body weight may also be used to provide resistance as when a person does push-ups, pull-ups, or abdominal crunches. -weight training weight training has long been recognized as a means to build lean body mass and develop and maintain muscle strength and endurance. -additional benefits of weight training, however, have emerged only recently. -progressive weight training not only increases muscle strength and endurance, but it also prevents and man- ages several chronic diseases, including cardiovascular disease, and enhances psy- chological well-being.24 weight training can also help to maximize and maintain bone mass.25 even in women past menopause (when most women are losing bone), a one-year program of weight training can improve bone density; in fact, the more weight lifted, the greater the improvement.26 by promoting strong muscles in the back and abdomen, weight training can im- prove posture and reduce the risk of back injury. -weight training can also help pre- vent the decline in physical mobility that often accompanies aging.27 older adults, even those in their eighties, who participate in weight training programs not only gain muscle strength but also improve their muscle endurance, which enables them to walk longer before exhaustion. -leg strength and walking endurance are powerful indicators of an older adult s physical abilities. -depending on the technique, weight training can emphasize either muscle strength or muscle endurance. -to emphasize muscle strength, combine high resist- ance (heavy weight) with a low number (8 to 10) of repetitions. -to emphasize mus- cle endurance, combine less resistance (lighter weight) with more (12 to 15) repetitions. -weight training enhances performance in other sports, too. -swimmers can develop a more efficient stroke and tennis players, a more powerful serve, when they train with weights.28 energy systems, fuels, and nutrients to support activity nutrition and physical activity go hand in hand. -activity demands carbohydrate and fat as fuel, protein to build and maintain lean tissues, vitamins and minerals to support both energy metabolism and tissue building, and water to help distribute the fuels and to dissipate the resulting heat and wastes. -this section describes how nutrition supports a person who decides to get up and go. -the energy systems of physical activity atp and cp muscles contract fast. -when called upon, they respond quickly without taking time to metabolize fat or carbohydrate for energy. -in the first fractions of a second, mus- cles starting to move depend on their supplies of quick-energy compounds to power their movements. -exercise physiologists know these compounds by their abbrevia- tions, atp and cp. -atp as chapter 7 described, all of the energy-yielding nutrients carbohydrate, fat, and protein can enter metabolic pathways that make the high-energy com- pound atp (adenosine triphosphate). -atp is present in small amounts in all body tissues all the time, and it can deliver energy instantly. -in the muscles, atp provides the chemical driving force for contraction. -when an atp molecule is split, its energy is released, and the muscle cells channel some of that energy into mechanical move- ment and most of it into heat. -cp immediately after the onset of a demand, before muscle atp pools dwindle, a muscle enzyme begins to break down another high-energy compound that is stored fitness: physical activity, nutrients, and body adaptations 485 in the muscle, cp, or creatine phosphate. -cp is made from creatine, a compound commonly found in muscles, with a phosphate group attached, and it can split (anaerobically) to release phosphate and replenish atp supplies. -supplies of cp in a muscle last for only about 10 seconds, producing enough quick energy without oxygen for a 100-meter dash. -when activity ceases and the muscles are resting, atp feeds energy back to cp by giving up one of its phosphate groups to creatine. -thus cp is produced during rest by reversing the process that occurs during muscular activity. -(highlight 14 includes creatine supplements in its discussion of substances commonly used in the pursuit of fitness.) -the energy-yielding nutrients to meet the more prolonged demands of sus- tained activity, the muscles generate atp from the more abundant fuels: carbohy- drate, fat, and protein. -the breakdown of these nutrients generates atp all day every day, and so maintains the supply. -muscles always use a mixture of fuels never just one. -during rest, the body derives more than half of its atp from fatty acids and most of the rest from glucose, along with a small percentage from amino acids. -during physical activity, the body adjusts its mixture of fuels. -how much of which fuel the muscles use during physical activity depends on an interplay among the fuels available from the diet, the intensity and duration of the activity, and the degree to which the body is conditioned to perform that activity. -the next sections explain these relationships by examining each of the energy-yielding nutrients individu- ally, but keep in mind that although one fuel may predominate at a given time, the other two will still be involved. -table 14-3 shows how fuel use changes accord- ing to the intensity and duration of the activity. -as you read about each of the energy-yielding nutrients, notice how its contribu- tion to the fuel mixture shifts depending on whether the activity is anaerobic or aerobic. -anaerobic activities are associated with strength, agility, and split-second surges of power. -the jump of the basketball player, the slam of the tennis serve, the heave of a bodybuilder lifting weights, and the blast of the fullback through the op- posing line all involve anaerobic work. -such high-intensity, short-duration activi- ties depend mostly on glucose as the chief energy fuel. -endurance activities of low-to-moderate intensity and long duration depend more on fat to provide energy aerobically. -the ability to continue swimming to the shore, to keep on hiking to the top of the mountain, or to continue pedaling all the way home reflects aerobic capacity. -as mentioned earlier, aerobic capacity is also crucial to maintaining a healthy heart and circulatory system. -the relationships among fuels and physical activity bear heavily on what foods best support your chosen activities. -s e g a m i y t t e g / k n a b e g a m i e h t / n o s t a w n o m s i split-second surges of power as in the heave of a barbell or jump of a basketball player involve anaerobic work. -recall from chapter 7 that anaerobic means not requiring oxygen. -during rest: atp + creatine cp during activity: cp atp + creatine fuel mixture during activity depends on: diet intensity and duration of activity training glucose use during physical activity glucose, stored in the liver and muscles as glycogen, is vital to physical activity. -dur- ing exertion, the liver breaks down its glycogen and releases the glucose into the bloodstream. -the muscles use this glucose as well as their own private glycogen cp, creatine phosphate (also called phosphocreatine): a high-energy compound in muscle cells that acts as a reservoir of energy that can maintain a steady supply of atp. -cp provides the energy for short bursts of activity. -table 14-3 fuels used for activities of different intensities and durations activity intensity activity duration preferred fuel source oxygen needed? -activity example extremea very high high moderate 8 to 10 sec atp-cp (immediate availability) 20 sec to 3 min atp from carbohydrate (lactate) 3 min to 20 min atp from carbohydrate more than 20 min atp from fat no (anaerobic) no (anaerobic) yes (aerobic) yes (aerobic) 100-yard dash, shot put 1 4-mile run at maximal speed cycling, swimming, or running hiking aall levels of activity intensity use the atp-cp system initially; extremely intense short-term activities rely solely on the atp-cp system. -486 chapter 14 sustained muscular efforts as in a long-dis- tance rowing event or a cross-country run involve aerobic work. -to fill glycogen stores, eat plenty of carbohydrate-rich foods. -reminder: lactate is the product of anaero- bic glycolysis. -stores to fuel their work. -glycogen supplies can easily support everyday activities but are limited to less than 2000 kcalories of energy, enough for about 20 miles of run- ning.29 the more glycogen the muscles store, the longer the glycogen will last dur- ing physical activity, which in turn influences performance. -when glycogen is depleted, the muscles become fatigued. -diet affects glycogen storage and use how much carbohydrate a person eats influences how much glycogen is stored. -a classic study compared fuel use during activity among three groups of runners on different diets.30 for several days before testing, one group consumed a normal mixed diet, a second group consumed a high-carbohydrate diet, and the third group consumed a no-carbohydrate diet (fat and protein diet). -as figure 14-3 shows, the high-carbohydrate diet allowed the run- ners to keep going longer before exhaustion. -this study and many others that fol- lowed have confirmed that high-carbohydrate diets enhance endurance by ensuring ample glycogen stores. -t i d e o t o h p / f f l o w - g n u o y d i v a d intensity of activity affects glycogen use how long an exercising person s glycogen will last depends not only on diet, but also on the intensity of the activity. -moderate activities, such as jogging, during which breathing is steady and easy, use glycogen slowly. -the lungs and circulatory system have no trouble keeping up with the muscles need for oxygen. -the individual breathes easily, and the heart beats steadily the activity is aerobic. -the muscles derive their energy from both glucose and fatty acids. -by depending partly on fatty acids, moderate aerobic activity con- serves glycogen. -intense activities the kind that make it difficult to catch your breath, such as a quarter-mile race use glycogen quickly. -in such activities, the muscles break down glucose to pyruvate anaerobically, producing atp quickly. -lactate when the rate of glycolysis exceeds the capacity of the mitochondria to ac- cept hydrogens with their electrons for the electron transport chain, the accumulat- ing pyruvate molecules are converted to lactate. -at low intensities, lactate is readily cleared from the blood, but at higher intensities, lactate accumulates. -when the rate of lactate production exceeds the rate of clearance, intense activity can be maintained for only 1 to 3 minutes (as in a 400- to 800-meter race or a boxing figure 14-3 the effect of diet on physical endurance a high-carbohydrate diet can increase an athlete s endurance. -in this study, the fat and protein diet provided 94 percent of kcalories from fat and 6 percent from protein; the normal mixed diet provided 55 percent of kcalories from carbohy- drate; and the high-carbohydrate diet provided 83 percent of kcalories from carbo- hydrate. -fat and protein diet normal mixed diet high-carbohydrate diet . -c n i , t i d e o t o h p / n m a k i i e n n o b maximum endurance time: 57 min 114 min 167 min fitness: physical activity, nutrients, and body adaptations 487 match). -lactate was long blamed for muscle fatigue, but recent research disputes this idea. -working muscles may produce lactate and experience fatigue, but the lac- tate does not cause the fatigue.31 when production of lactate exceeds the ability of the muscles to use it, they re- lease it, and it travels in the blood to the liver. -there, liver enzymes convert the lac- tate back into glucose. -glucose can then return to the muscles to fuel additional activity. -(the recycling process that regenerates glucose from lactate is known as the cori cycle, as shown in figure 7-6 on p. -220.) -duration of activity affects glycogen use glycogen use depends not only on the intensity of an activity, but also on its duration. -within the first 20 minutes or so of moderate activity, a person uses mostly glycogen for fuel about one-fifth of the available glycogen. -as the muscles devour their own glycogen, they become raven- ous for more glucose, and the liver responds by emptying out its glycogen stores. -after 20 minutes, a person who continues exercising moderately (mostly aero- bically) begins to use less and less glycogen and more and more fat for fuel (review table 14-3 on p. 485). -still, glycogen use continues, and if the activity lasts long enough and is intense enough, blood glucose declines and muscle and liver glyco- gen stores are depleted. -physical activity can continue for a short time thereafter only because the liver scrambles to produce, from lactate and certain amino acids, the minimum amount of glucose needed to briefly forestall total depletion. -glucose depletion after a couple of hours of strenuous activity, glucose stores are depleted. -when depletion occurs, it brings nervous system function to a near halt, making continued exertion almost impossible. -marathon runners refer to this point of glucose exhaustion as hitting the wall. -to avoid such debilitation, endurance athletes try to maintain their blood glu- cose for as long as they can. -the following guidelines will help endurance atheletes maximize glucose supply: eat a high-carbohydrate diet (approximately 8 grams of carbohydrate per kilogram of body weight or about 70 percent of energy intake) regularly. -* take glucose (usually in sports drinks) periodically during activities that last for 45 minutes or more. -s e g a m i y t t e g / i x a t / y h a e l d i v a d moderate- to high-intensity aerobic exercises that can be sustained for only a short time (less than 20 minutes) use some fat, but more glucose for fuel. -eat carbohydrate-rich foods (approximately 60 grams of carbohydrate) for perspective, snack ideas providing 60 g immediately following activity. -train the muscles to store as much glycogen as possible. -the last section of this chapter, diets for physically active people, discusses how to design a high-carbohydrate diet for performance, and the how to on p. 488 de- scribes carbohydrate loading a technique used to maximize glycogen stores for long endurance competitions. -glucose during activity muscles can obtain the glucose they need not only from glycogen stores, but also from foods and beverages consumed during activity. -con- suming carbohydrate is especially useful during exhausting endurance activities (lasting more than 45 minutes) and during games such as soccer or hockey, which last for hours and demand repeated bursts of intense activity.32 endurance athletes often run short of glucose by the end of competitive events, and they are wise to take light carbohydrate snacks or drinks (about 200 kcalories) periodically during activ- ity.33 during the last stages of an endurance competition, when glycogen is running low, glucose consumed during the event can slowly make its way from the digestive tract to the muscles and augment the body s supply of glucose enough to forestall exhaustion. -* percentage of energy intake is meaningful only when total energy intake is known. -consider that at high energy intakes (say, 5000 kcalories/day), even a moderate carbohydrate diet (40 percent of energy intake) supplies 500 grams of carbohydrate enough for a 137-pound (62 kilogram) athlete in heavy training. -by comparison, at a moderate energy intake (2000 kcalories/day), a high carbohydrate intake (70 percent of energy intake) supplies 350 grams plenty of carbohydrate for most people, but not enough for athletes in heavy training. -carbohydrate: 16 oz sports drink and a small bagel 16 oz milk and 4 oatmeal cookies 8 oz pineapple juice and a granola bar carbohydrate loading: a regimen of moderate exercise followed by the consumption of a high-carbohydrate diet that enables muscles to store glycogen beyond their normal capacities; also called glycogen loading or glycogen super compensation. -488 chapter 14 how to maximize glycogen stores: carbohydrate loading some athletes use a technique called carbohydrate loading to trick their mus- cles into storing extra glycogen before a competition. -carbohydrate loading can nearly double muscle glycogen concentra- tions. -in general, the athlete tapers train- ing during the week before the competition and then eats a high- carbohydrate diet during the three days just prior to the event.a specifically, the athlete follows the plan in the accompany- ing table. -in this carbohydrate loading plan, glycogen storage occurs slowly, and athletes must alter their training for sev- eral days before the event. -in contrast, a group of researchers have designed a quick method of carbohydrate loading that has produced promising re- sults. -the researchers found that athletes ae. -coleman, carbohydrate and exercise, in sports nutrition: a practice manual for professionals, 4th ed., ed. -m. dunford (chicago: the american dietetic association, 2006), pp. -14 32. before the event training intensity training dietary duration carbohydrate 6 days 4 5 days 2 3 days 1 day moderate (70% vo2max) moderate (70% vo2max) moderate (70% vo2max) rest 90 min 40 min 20 min normal (5 g/kg body weight) normal (5 g/kg body weight) high-carbohydrate (10 g/kg body weight) high-carbohydrate (10 g/kg body weight) could attain above-normal concentrations of muscle glycogen by eating a high-carbo- hydrate diet (10 g/kg body weight) after a short (3 minutes) but very intense bout of exercise.b more studies are needed to con- firm these findings and to determine whether an exercise session of less intensity and shorter duration would accomplish the same results. -extra glycogen gained through carbohy- drate loading can benefit an athlete who must keep going for 90 minutes or longer. -those who exercise for shorter times simply need a regular high-carbohydrate diet. -in a hot climate, extra glycogen confers an additional advantage: as glycogen breaks down, it releases water, which helps to meet the athlete s fluid needs. -bt. -j. fairchild and coauthors, rapid carbohydrate loading after a short bout of near maximal-intensity exercise, medicine and science in sports and exercise 34 (2002): 980 986. glucose after activity eating high-carbohydrate foods after physical activity also enlarges glycogen stores. -a high-carbohydrate meal eaten within 15 minutes after physical activity accelerates the rate of glycogen storage by 300 percent. -after two hours, the rate of glycogen storage declines by almost half. -despite this slower rate of glycogen restoration, muscles continue to accumulate glycogen as long as athletes eat carbohydrate-rich foods within two hours following activity.34 this is particularly important to athletes who train hard more than once a day. -chapter 4 introduced the glycemic effect and discussed the possible health ben- efits of eating a low-glycemic diet. -for athletes wishing to maximize muscle glyco- gen synthesis after strenuous training, however, eating foods with a high glycemic index may be more beneficial (see figure 4-13 on p. 116).35 foods with a high glycemic index elicit greater rates of glycogen synthesis compared to foods with a low glycemic index.36 s e g a m i y t t e g / c s i d o t o h p training affects glycogen use training, too, affects how much glycogen mus- cles will store. -muscle cells that repeatedly deplete their glycogen through hard work adapt to store greater amounts of glycogen to support that work. -conditioned muscles also rely less on glycogen and more on fat for energy, so glycogen breakdown and glucose use occur more slowly in trained than in un- trained individuals at a given work intensity.37 a person attempting an activity for the first time uses much more glucose than an athlete who is trained to perform it. -oxygen delivery to the muscles by the heart and lungs plays a role, but equally im- portantly, trained muscles are better equipped to use the oxygen because their cells contain more mitochondria. -untrained muscles depend more heavily on anaer- obic glucose breakdown, even when physical activity is just moderate. -fat use during physical activity as figure 14-3 (p. 486) shows, researchers have long recognized the importance of a high-carbohydrate diet for endurance performance. -when endurance ath- letes fat load by consuming high-fat, low-carbohydrate diets for one to three abundant energy from the breakdown of fat can come only from aerobic metabolism. -in popular magazine articles and on the internet, foods with a high glycemic index are sometimes called high impact carbs, and foods with a low glycemic index are sometimes called low impact carbs. -reminder: the mitochondria are the struc- tures within a cell responsible for produc- ing atp (see figure 7-1 on p. 214). -fitness: physical activity, nutrients, and body adaptations 489 i s b r o c / s n i m m u c m i j low- to moderate-intensity aerobic exercises that can be sustained for a long time (more than 20 minutes) use some glucose, but more fat for fuel. -days, their performance is impaired because their small glycogen stores are de- pleted quickly.38 endurance athletes who adhere to a high-fat, low-carbohydrate diet for more than a week, however, adapt by relying more on fat to fuel activ- ity. -even with fat adaptation, however, performance benefits are not consis- tently evident.39 in some cases, athletes on high-fat diets experience greater fatigue and perceive the activity to be more strenuous than athletes on high- carbohydrate diets.40 diets high in saturated fat carry risks of heart disease, too. -physical activity of- fers some protection against cardiovascular disease, but athletes, like everyone else, can suffer heart attacks and strokes. -most nutrition experts agree that the potential for adverse health effects of prolonged high-fat diets continues to outweigh any possible benefit to performance. -sports nutrition experts recommend that endurance athletes consume 20 to 30 percent of their energy from fat to meet nutrient and energy needs.41 athletes who restrict fat below 20 percent of total energy intake may fail to consume adequate energy and nutrients. -in contrast to dietary fat, body fat stores are extremely important during physical activity, as long as the activity is not too intense. -unlike glycogen stores, the body s fat stores can usually provide more than 70,000 kcalories and fuel hours of activity without running out.42 the fat used in physical activity is liberated as fatty acids from the internal fat stores and from the fat under the skin. -areas that have the most fat to spare do- nate the greatest amounts to the blood (although they may not be the areas that appear fattiest). -thus spot reducing doesn t work because muscles do not own the fat that surrounds them. -fat cells release fatty acids into the blood, not into the underlying muscles. -then the blood gives to each muscle the amount of fat that it needs. -proof of this is found in a tennis player s arms the skinfold measures are the same in both arms, even though the muscles of one arm work much harder and may be larger than those of the other. -a balanced fitness program that in- cludes strength training, however, will tighten muscles underneath the fat, im- proving the overall appearance. -keep in mind that some body fat is essential to good health. -duration of activity affects fat use early in an activity, as the muscles draw on fatty acids, blood levels fall. -if the activity continues for more than a few minutes, the hormone epinephrine signals the fat cells to begin breaking down their stored triglycerides and liberating fatty acids into the blood. -after about 20 minutes of physical activity, the blood fatty acid concentration surpasses the normal resting concentration. -thereafter, sustained, moderate activity uses body fat stores as its major fuel. -intensity of activity affects fat use the intensity of physical activity also affects fat use. -as the intensity of activity increases, fat makes less and less of a contribution to the fuel mixture. -remember that fat can be broken down for en- ergy only by aerobic metabolism. -for fat to fuel activity, then, oxygen must be abundantly available. -if a person is breathing easily during activity, the mus- cles are getting all the oxygen they need and are able to use more fat in the fuel mixture. -training affects fat use training repeated aerobic activity produces the adaptations that permit the body to draw more heavily on fat for fuel. -training stimulates the muscle cells to manufacture more and larger mitochondria, the power house structures of the cells that produce atp for energy. -another adapta- tion: the heart and lungs become stronger and better able to deliver oxygen to mus- cles at high activity intensities. -still another: hormones in the body of a trained person slow glucose release from the liver and speed up the use of fat instead. -these adaptations reward not only trained athletes but all active people; a person who trains by way of aerobic activities such as distance running or cycling becomes well suited to the activity. -490 chapter 14 to conserve protein, eat a diet adequate in energy and rich in carbohydrate. -protein use during physical activity and between times table 14-3 on p. 485 summarizes the fuel uses discussed so far, but does not include the third energy-yielding nutrient, protein, because protein is not a major fuel for physical activity. -nevertheless, physically active people use protein just as other peo- ple do to build muscle and other lean tissues and, to some extent, to fuel activity. -the body does, however, handle protein differently during activity than during rest. -protein used in muscle building synthesis of body proteins is suppressed dur- ing activity. -in the hours of recovery following activity, though, protein synthesis ac- celerates beyond normal resting levels. -as noted earlier, eating high-carbohydrate foods immediately after exercise accelerates muscle glycogen storage. -similarly, re- search shows that eating carbohydrate, together with protein, enhances muscle pro- tein synthesis.43 remember that the body adapts and builds the molecules, cells, and tissues it needs for the next period of activity. -whenever the body remodels a part of itself, it also tears down old structures to make way for new ones. -repeated activity, with just a slight overload, triggers the protein-dismantling and protein-synthesiz- ing equipment of each muscle cell to make needed changes that is, to adapt. -the physical work of each muscle cell acts as a signal to its dna and rna to be- gin producing the kinds of proteins that will best support that work. -take jogging, for example. -in the first difficult sessions, the body is not yet equipped to perform aerobic work easily, but with each session, the cells genetic material gets the mes- sage that an overhaul is needed. -in the hours that follow the session, the genes send molecular messages to the protein-building equipment that tell it what old struc- tures to break down and what new structures to build. -within the limits of its ge- netic potential, the body responds. -an athlete may add between 1/4 ounce and 1 ounce (between 7 and 28 grams) of body protein to existing muscle mass each day during active muscle-building phases of training. -also, more mitochondria are cre- ated to facilitate efficient aerobic metabolism. -over a few weeks time, remodeling occurs and jogging becomes easier. -protein used as fuel not only do athletes retain more protein in their muscles, but they also use more protein as fuel. -muscles speed up their use of amino acids for energy during physical activity, just as they speed up their use of fat and carbohy- drate. -still, protein contributes only about 10 percent of the total fuel used, both dur- ing activity and during rest. -the most active people of all, endurance athletes, use up large amounts of all energy fuels, including protein, during performance, but such athletes also eat more food and therefore usually consume enough protein. -diet affects protein use during activity the factors that affect how much pro- tein is used during activity seem to be the same three that influence the use of fat and carbohydrate one factor is diet. -people who consume diets adequate in energy and rich in carbohydrate use less protein than those who eat protein- and fat-rich diets. -recall that carbohydrates spare proteins from being broken down to make glucose when needed. -because physical activity requires glucose, a diet lacking in carbohydrate necessitates the conversion of amino acids to glucose. -the same is true for diet high in fat because fatty acids can never provide glucose. -intensity and duration of activity affect protein use during activity a second factor, the intensity and duration of activity, also modifies protein use. -en- durance athletes who train for more than an hour a day, engaging in aerobic activ- ity of moderate intensity and long duration, may deplete their glycogen stores by the end of their workouts and become somewhat more dependent on body protein for energy. -in contrast, anaerobic strength training does not use more protein for energy, but it does demand more protein to build muscle. -thus the protein needs of both endurance and strength athletes are higher than those of sedentary people, but cer- tainly not as high as the protein intakes many athletes consume. -fitness: physical activity, nutrients, and body adaptations 491 for perfect functioning, every nutrient is needed. -training affects protein use a third factor that influences a person s use of pro- tein during physical activity is the extent of training. -particularly in strength ath- letes such as bodybuilders, the higher the degree of training, the less protein a person uses during an activity. -protein recommendations for active people as mentioned, all active peo- ple, and especially athletes in training, probably need more protein than sedentary people do. -endurance athletes, such as long-distance runners and cyclists, use more protein for fuel than strength or power athletes do, and they retain some, especially in the muscles used for their sport. -strength athletes, such as bodybuilders, and power athletes, such as football players, use less protein for fuel, but they still use some and retain much more. -therefore, all athletes in training should attend to pro- tein needs, but they should first meet their energy needs with adequate carbohy- drate intakes. -without adequate carbohydrate intake, athletes will burn off as fuel the very protein that they wish to retain in muscle. -how much protein, then, should an active person consume? -although the dri committee does not recommend greater than normal protein intakes for athletes, other authorities do.44 these recommendations specify different protein intakes for athletes pursuing different activities (see table 14-4).45 a later section translates protein recommendations into a diet plan and shows that no one needs protein supplements, or even large servings of meat, to obtain the highest recommended protein intakes. -(chapter 6 concluded that most people receive more than enough protein without supplements and reviewed the potential dangers of using protein and amino acid supplements.) -s e g a m i y t t e g / e n o t s / a m o h t b o b in summary the mixture of fuels the muscles use during physical activity depends on diet, the intensity and duration of the activity, and training. -during intense activ- ity, the fuel mix is mostly glucose, whereas during less intense, moderate ac- tivity, fat makes a greater contribution. -with endurance training, muscle cells adapt to store more glycogen and to rely less on glucose and more on fat for energy. -athletes in training may need more protein than sedentary people do, but they typically eat more food as well and therefore obtain enough protein. -vitamins and minerals to support activity many of the vitamins and minerals assist in releasing energy from fuels and in transporting oxygen. -this knowledge has led many people to believe, mistakenly, table 14-4 recommended protein intakes for athletes recommendations (g/kg/day) protein intakes (g/day) rda for adults recommended intake for power (strength or speed) athletes recommended intake for endurance athletes u.s. average intake 0.8 1.6 1.7 1.2 1.6 males 56 112 119 females 44 88 94 84 112 66 88 95 65 note: daily protein intakes are based on a 70-kilogram (154-pound) man and 55-kilogram (121-pound) woman. -sources: committee on dietary reference intakes, dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein and amino acids (washington, d.c.: national academies press, 2005), pp. -660 661; position of the american dietetic association, dietitians of canada, and the american college of sports medicine: nutrition and athletic performance, journal of the american dietetic association 100 (2000): 1543 1556. -492 chapter 14 the tolerable upper intake level (ul) for vitamin e is 1000 mg per day. -that vitamin and mineral supplements offer physically active people both health benefits and athletic advantages. -(review highlight 10 for a discussion of vitamin and mineral supplements, and see highlight 14, which explores supplements and other products people use in the hope of enhancing athletic performance.) -supplements nutrient supplements do not enhance the performance of well- nourished people. -deficiencies of vitamins and minerals, however, do impede per- formance. -in general, active people who eat enough nutrient-dense foods to meet energy needs also meet their vitamin and mineral needs. -after all, active people eat more food; it stands to reason that with the right choices, they ll get more nutrients. -athletes who lose weight to meet low body-weight requirements, however, may eat so little food that they fail to obtain all the nutrients they need.46 the practice of making weight is opposed by many health and fitness organizations, but for athletes who choose this course of action, a single daily multivitamin-mineral sup- plement that provides no more than the dri recommendations for nutrients may be beneficial. -some athletes believe that taking vitamin or mineral supplements directly be- fore competition will enhance performance. -these beliefs are contrary to scientific reality. -most vitamins and minerals function as small parts of larger working units. -after entering the blood, they have to wait for the cells to combine them with their appropriate other parts so that they can do their work. -this takes time hours or days. -vitamins or minerals taken right before an event are useless for improving performance, even if the person is actually suffering deficiencies of them. -in general, then, most active people who eat well-balanced meals do not need vitamin or mineral supplements. -two nutrients, vitamin e and iron, do merit spe- cial mention here, however, each for a different reason. -vitamin e is discussed be- cause so many athletes take vitamin e supplements. -iron is discussed because some athletes may be unaware that they need iron supplements. -vitamin e vitamin e and other antioxidant nutrients may be especially effective for athletes exercising in extreme environments, such as heat, cold, and high alti- tudes. -during prolonged, high-intensity physical activity, the muscles consumption of oxygen increases tenfold or more, enhancing the production of damaging free radicals in the body.47 vitamin e is a potent antioxidant that vigorously defends cell membranes against oxidative damage. -some athletes and active people take mega- doses of vitamin e in hopes of preventing such oxidative damage to muscles. -in some studies, supplementation with vitamin e does seem to protect against exercise- induced oxidative stress. -other studies show no effect on oxidative stress, however, and a few show enhanced stress after vitamin e supplementation.48 there is little ev- idence that vitamin e supplements can improve performance.49 clearly, more re- search is needed, but in the meantime, active people can benefit by using vegetable oils and eating generous servings of antioxidant-rich fruits and vegetables regularly. -iron deficiency physically active young women, especially those who engage in endurance activities such as distance running, are prone to iron deficiency.50 habit- ually low intakes of iron-rich foods, high iron losses through menstruation, and the high demands of muscles for the iron-containing electron carriers of the mitochon- dria and the muscle protein myoglobin can cause iron deficiency in physically ac- tive young women. -adolescent female athletes who eat vegetarian diets may be particularly vulner- able to iron deficiency.51 as chapter 13 explained, the bioavailability of iron is of- ten poor in vegetarian diets. -to protect against iron deficiency, vegetarian athletes need to select good dietary sources of iron (fortified cereals, legumes, nuts, and seeds) and include vitamin c-rich foods with each meal. -as long as vegetarian ath- letes, like all athletes, consume enough nutrient-dense foods, they can perform as well as anyone. -reminder: iron is an essential component of hemoglobin, the protein that transports oxygen throughout the body. -iron-deficiency anemia iron-deficiency anemia impairs physical performance because the hemoglobin in red blood cells is needed to deliver oxygen to the cells for energy metabolism. -without adequate oxygen, an active person cannot perform fitness: physical activity, nutrients, and body adaptations 493 i s b r o c / s i r r o m . -r n i v e k aerobic activities and tires easily. -whether iron deficiency without clinical signs of anemia impairs physical performance is less clear.52 sports anemia early in training, athletes may develop low blood hemoglobin for a while. -this condition, sometimes called sports anemia, is not a true iron- deficiency condition. -strenuous aerobic activity promotes destruction of the more fragile, older red blood cells, and the resulting cleanup work reduces the blood s iron content temporarily. -strenuous activity also expands the blood s plasma volume, thereby reducing the red blood cell count per unit of blood. -however, the red blood cells do not diminish in size or number as in anemia, so their oxygen-carrying capacity is not hindered. -most researchers view sports anemia as an adaptive, tem- porary response to endurance training. -iron-deficiency anemia requires iron supple- mentation, but sports anemia does not. -iron recommendations for athletes the best strategy for maintaining ade- quate iron nutrition depends on the individual. -menstruating women may border on iron deficiency even without the iron losses incurred by physical activity. -active teens of both genders have high iron needs because they are growing. -especially for women and teens, then, prescribed supplements may be needed to correct iron defi- ciencies. -physicians use the results of blood tests to determine whether such supple- mentation is needed. -(review chapter 13 for many more details about iron, and see appendix e for a description of the tests used in assessing its status.) -in summary with the possible exception of iron, well-nourished active people and athletes do not need nutrient supplements. -female athletes need to pay special atten- tion to their iron needs. -to prevent dehydration and the fatigue that accompanies it, drink liquids before, during, and after physical activity. -fluids and electrolytes to support activity the need for water far surpasses the need for any other nutrient. -the body relies on watery fluids as the medium for all of its life-supporting activities, and if it loses too much water, its well-being will be compromised. -obviously, the body loses water via sweat. -breathing uses water, too, exhaled as vapor. -during physical activity, water losses from both routes are significant, and dehydration becomes a threat. -dehydration s first symptom is fatigue: a water loss of greater than 2 percent of body weight can reduce a person s capacity to do mus- cular work.53 with a water loss of about 7 percent, a person is likely to collapse. -fluid losses via sweat recall from chapter 7 that working muscles produce heat as a by-product of energy metabolism. -during intense activity, muscle heat production can be 15 to 20 times greater than at rest. -the body cools itself by sweat- ing. -each liter of sweat dissipates almost 600 kcalories of heat, preventing a rise in body temperature of almost 10 degrees on the celsius scale. -the body routes its blood supply through the capillaries just under the skin, and the skin secretes sweat to evaporate and cool the skin and the underlying blood. -the blood then flows back to cool the deeper body chambers. -hyperthermia in hot, humid weather, sweat doesn t evaporate well because the surrounding air is already laden with water. -in hyperthermia, body heat builds up and triggers maximum sweating, but without sweat evaporation, little cooling takes place. -in such conditions, active people must take precautions to prevent heat stroke. -to reduce the risk of heat stroke, drink enough fluid before and during the activity, rest in the shade when tired, and wear lightweight clothing that allows sweat to evaporate.54 (hence the danger of rubber or heavy suits that supposedly promote weight loss during physical activity they promote profuse sweating, pre- vent sweat evaporation, and invite heat stroke.) -if you ever experience any of the note: 10 degrees on the celsius scale is about 18 degrees on the fahrenheit scale. -sports anemia: a transient condition of low hemoglobin in the blood, associated with the early stages of sports training or other strenuous activity. -hyperthermia: an above-normal body temperature. -heat stroke: a dangerous accumulation of body heat with accompanying loss of body fluid. -494 chapter 14 water is the best fluid for most physically active people, but some consumers prefer the flavors of sports drinks. -symptoms of dehydration and heat stroke: headache nausea dizziness clumsiness stumbling sudden cessation of sweating (hot, dry skin) confusion or other mental changes hypothermia: a below-normal body temperature. -hourly sweat rate: the amount of weight lost plus fluid consumed during exercise per hour. -d o o f k c o t s / y h p a r g o t o h p i n a i r a m k c i r symptoms of heat stroke listed in the margin, stop your activity, sip fluids, seek shade, and ask for help. -heat stroke can be fatal, young people often die of it, and these symptoms demand attention. -hypothermia in cold weather, hypothermia, or low body temperature, can be as serious as heat stroke is in hot weather. -inexperienced, slow runners participating in long races on cold or wet, chilly days are especially vulnerable to hypothermia. -slow runners who produce little heat can become too cold if clothing is inadequate. -early symptoms of hypothermia include shivering and euphoria. -as body tempera- ture continues to fall, shivering may stop, and weakness, disorientation, and apathy may occur. -each of these symptoms can impair a person s ability to act against a further drop in body temperature. -even in cold weather, however, the active body still sweats and still needs fluids. -the fluids should be warm or at room temperature to help protect against hypothermia. -fluid replacement via hydration endurance athletes can easily lose 1.5 liters or more of fluid during each hour of activity. -to prepare for fluid losses, a person must hydrate before activity. -to replace fluid losses, the person must rehydrate during and after activity. -(table 14-5 presents one schedule of hydration for physical activity.) -even then, in hot weather, the gi tract may not be able to absorb enough water fast enough to keep up with sweat losses, and some degree of dehydration may be in- evitable. -athletes who know their body s hourly sweat rate can strive to replace the total amount of fluid lost during activity to prevent dehydration.55 athletes who are preparing for competition are often advised to drink extra flu- ids in the days immediately before the event, especially if they are still training. -the extra water is not stored in the body, but drinking extra water ensures maximum hydration at the start of the event. -full hydration is imperative for every athlete both in training and in competition. -the athlete who arrives at an event even slightly dehydrated begins with a disadvantage. -what is the best fluid for an exercising body? -for noncompetitive, everyday ac- tive people, plain, cool water is recommended, especially in warm weather, for two reasons: (1) water rapidly leaves the digestive tract to enter the tissues where it is needed, and (2) it cools the body from the inside out. -for endurance athletes, carbo- hydrate-containing beverages may be appropriate. -fluid ingestion during the event has the dual purposes of replenishing water lost through sweating and providing a source of carbohydrate to supplement the body s limited glycogen stores. -carbohy- drate depletion brings on fatigue in the athlete, but as already mentioned, fluid loss and the accompanying buildup of body heat can be life-threatening. -thus the first priority for endurance athletes should be to replace fluids. -many good-tasting drinks are marketed for active people; the how to on p. 495 compares them with water. -electrolyte losses and replacement when a person sweats, small amounts of electrolytes the electrically charged minerals sodium, potassium, chloride, and table 14-5 hydration schedule for physical activity when to drink 2 hr before activity 15 min before activity every 15 min during activity after activity amount of fluid 2 to 3 c 1 to 2 c 1 2 to 2 c (drink enough to minimize loss of body weight, but don t overdrink.) -2 c for each pound of body weight losta a drinking 2 cups of fluid every 20 to 30 minutes after exercise until the total amount required is consumed is more effective for rehydration than drinking the needed amount all at once. -rapid fluid replacement after exercise stimulates urine produc- tion and results in less body water retention. -source: r. murray, fluid, electrolytes, and exercise in sports nutrition: a practice manual for professionals. -4th ed., ed. -m. dunford (chicago: the american dietetic association, 2005), pp. -94 115; d.j. -casa, p.m. clarkson, and w.o. -roberts, american college of sports medicine roundtable on hydration and physical activity: consensus statements, current sports medicine reports 4 (2005): 115 127. fitness: physical activity, nutrients, and body adaptations 495 magnesium are lost from the body along with water. -losses are greatest in begin- ners; training improves electrolyte retention. -to replenish lost electrolytes, a person ordinarily needs only to eat a regular diet that meets energy and nutrient needs. -in events lasting more than one hour, sports drinks may be needed to replace fluids and electrolytes. -salt tablets can worsen de- hydration and impair performance; they increase potassium losses, irritate the stomach, and cause vomiting. -hyponatremia when athletes compete in endurance sports lasting longer than three hours, replenishing electrolytes is crucial. -if athletes sweat profusely over a long period of time and do not replace lost sodium, a dangerous condition known as hy- ponatremia may result. -research shows that some athletes who sweat profusely may also lose more sodium in their sweat than others and are prone to debilitating heat cramps.56 these athletes lose twice as much sodium in sweat as athletes who don t cramp. -depending on individual variation, exercise intensity, and changes in ambient temperature and humidity, sweat rates for these athletes can exceed 2 liters per hour.57 hyponatremia may also occur when endurance athletes drink such large amounts of water over the course of a long event that they overhydrate, diluting the body s flu- ids to such an extent that the sodium concentration becomes extremely low. -during long competitions, when athletes lose sodium through heavy sweating and consume excessive amounts of liquids, especially water, hyponatremia becomes likely. -some athletes may still be vulnerable to hyponatremia even when they drink sports drinks during an event.58 sports drinks do contain sodium, but as the how to points out, the sodium content of sports drinks is low and, in some cases, too low to replace sweat losses. -still, sports drinks do offer more sodium than plain water. -to prevent hyponatremia, athletes need to replace sodium during prolonged events. -they should favor sports drinks over water and eat pretzels in the last half how to evaluate sports drinks hydration is critical to optimal performance. -water best meets the fluid needs of most people, yet manufacturers market many good-tasting sports drinks for active people. -more than 20 power beverages compete for their share of the more than $1 billion market. -what do sports drinks have to offer? -fluid. -sports drinks offer fluids to help offset the loss of fluids during physical activity, but plain water can do this, too. -alternatively, diluted fruit juices or flavored water can be used if preferred to plain water. -glucose. -sports drinks offer simple sugars or glucose polymers that help maintain hydration and blood glucose and enhance performance as effectively as, or maybe even better than, water. -such measures are especially beneficial for strenuous endurance activities lasting longer than 45 minutes, during intense activities, or during prolonged competitive games that demand repeated intermittent activity.a sports drinks are also suitable for events lasting less than 45 minutes although plain water is appropriate as well.b fluid transport to the tissues from bever- ages containing up to 8 percent glucose is rapid. -most sports drinks contain about 7 percent carbohydrate (about half the sugar of ordinary soft drinks, or about 5 teaspoons in each 12 ounces). -less than 6 percent may not enhance performance, and more than 8 percent may cause ab- dominal cramps, nausea, and diarrhea. -although glucose does enhance en- durance performance in strenuous compet- itive events, for the moderate exerciser, it can be counterproductive if weight loss is the goal. -glucose is sugar, and like candy, it provides only empty kcalories no vitamins or minerals. -most sports drinks provide between 50 and 100 kcalories per cup. -sodium and other electrolytes. -sports drinks offer sodium and other electrolytes to help replace those lost during physical activity. -sodium in sports drinks also helps to in- crease the rate of fluid absorption from the a d.j. -casa, p.m. clarkson, and w.o. -roberts, american college of sports medicine roundtable on hydration and physical activity: consensus statements, current sports medicine reports 4 (2005): 115 127; e. coleman, fluid replacement for athletes, sports medicine digest 25 (2003): 76 77; inter-association task force on exertional heat illness consensus statement, nata news, june 2003. bposition of the american dietetic association, dietitians of canada, and the american college of sports medicine: nutrition and athletic performance, journal of the american dietetic association 100 (2000): 1543 1556. hyponatremia (high-poe-na-tree-mee-ah): a decreased concentration of sodium in the blood. -hypo = below natrium = sodium (na) emia = blood glucose polymers: compounds that supply glucose, not as single molecules, but linked in chains somewhat like starch. -the objective is to attract less water from the body into the digestive tract (osmotic attraction depends on the number, not the size, of particles). -gi tract and maintain plasma volume during activity and recovery. -most physically active people do not need to replace the minerals lost in sweat immediately; a meal eaten within hours of competition replaces these minerals soon enough. -most sports drinks are relatively low in sodium, however, so those who choose to use these beverages run little risk of excessive intake. -good taste. -manufacturers reason that if a drink tastes good, people will drink more, thereby ensuring adequate hydration. -for athletes who prefer the flavors of sports drinks over water, it may be worth paying for good taste to replace lost fluids. -psychological edge. -sports drinks provide a psychological edge for some people who associate the drinks with athletes and sports. -the need to belong is valid. -if the drinks boost morale and are used with care, they may do no harm. -for athletes who exercise for 45 minutes or more, sports drinks provide an advantage over water. -for most physically active people, though, water is the best fluid to replenish lost fluids. -the most important thing to do is drink even if you don t feel thirsty. -496 chapter 14 symptoms of hyponatremia: severe headache vomiting bloating, puffiness from water retention (shoes tight, rings tight) confusion seizure beer facts: beer is not carbohydrate-rich. -beer is kcalorie-rich, but only 1/3 of its kcalories are from carbohydrates. -the other 2/3 are from alcohol. -beer is mineral-poor. -beer contains a few minerals, but to replace the minerals lost in sweat, athletes need good sources such as fruit juices. -beer is vitamin-poor. -beer contains traces of some b vitamins, but it cannot com- pete with food sources. -beer causes fluid losses. -beer is a fluid, but alcohol is a diuretic and causes the body to lose valuable fluid. -of a long race.59 some athletes may need beverages with higher sodium concentra- tions than commercial sports drinks. -in the days before the event, especially an event in the heat, athletes should not restrict salt in their diets. -the symptoms of hyponatremia are similar to, but not the same as, those of dehydration (see the margin). -poor beverage choices: caffeine and alcohol athletes, like others, sometimes drink beverages that contain caffeine or alcohol. -each of these substances can influence physical performance. -caffeine caffeine is a stimulant, and athletes sometimes use it to enhance perfor- mance as highlight 14 explains. -carbonated soft drinks, whether they contain caf- feine or not, may not be a wise choice for athletes: bubbles make a person feel full quickly and so limit fluid intake. -alcohol some athletes mistakenly believe that they can replace fluids and load up on carbohydrates by drinking beer. -a 12-ounce beer provides 13 grams of carbo- hydrate one-third the amount of carbohydrate in a glass of orange juice the same size. -in addition to carbohydrate, beer also contains alcohol, of course. -energy from alcohol breakdown generates heat, but it does not fuel muscle work because alcohol is metabolized in the liver. -it is difficult to overstate alcohol s detrimental effects on physical activity. -alco- hol s diuretic effect impairs the body s fluid balance, making dehydration likely; af- ter physical activity, a person needs to replace fluids, not lose them by drinking beer. -alcohol also impairs the body s ability to regulate its temperature, increasing the likelihood of hypothermia or heat stroke. -alcohol also alters perceptions; slows reaction time; reduces strength, power, and endurance; and hinders accuracy, balance, eye-hand coordination, and coor- dination in general all opposing optimal athletic performance. -in addition, it de- prives people of their judgment, thereby compromising their safety in sports. -many sports-related fatalities and injuries involve alcohol or other drugs. -clearly, alcohol impairs performance, but physically active people do drink on occasion. -a word of caution: do not drink alcohol before exercising, and drink plenty of water after exercising before drinking alcohol. -in summary active people need to drink plenty of water; endurance athletes need to drink both water and carbohydrate-containing beverages, especially during train- ing and competition. -during events lasting longer than 3 hours, athletes need to pay special attention to replace sodium losses to prevent hyponatremia. -diets for physically active people no one diet best supports physical performance. -active people who choose foods within the framework of the diet-planning principles presented in chapter 2 can de- sign many excellent diets. -choosing a diet to support fitness above all, keep in mind that water is depleted more rapidly than any other nutrient. -a diet to support fitness must provide water, energy, and all the other nutrients. -water even casual exercisers must attend conscientiously to their fluid needs. -physical activity blunts the thirst mechanism, especially in cold weather. -during ac- fitness: physical activity, nutrients, and body adaptations 497 tivity, thirst signals come too late, so don t wait to feel thirsty before drinking. -to find out how much water is needed to replenish activity losses, weigh yourself before and after the activity the difference is almost all water. -one pound equals roughly 2 cups (500 milliliters) of fluid. -nutrient density a healthful diet is based on nutrient-dense foods foods that sup- ply adequate vitamins and minerals for the energy they provide. -active people need to eat both for nutrient adequacy and for energy. -a diet that is high in carbohydrate (60 to 70 percent of total kcalories), moderate in fat (20 to 30 percent), and adequate in protein (10 to 20 percent) ensures full glycogen and other nutrient stores. -carbohydrate on two occasions, the active person s regular high-carbohydrate, fiber-rich diet may require temporary adjustment. -both of these exceptions in- volve training for competition rather than for fitness in general. -one special occa- sion is the pregame meal, when fiber-rich, bulky foods are best avoided. -the pregame meal is discussed in a later section. -the other occasion is during intensive training, when energy needs may be so high as to outstrip the person s capacity to eat enough food to meet them. -at that point, added sugar and fat may be needed. -the athlete can add concentrated carbo- hydrate foods, such as dried fruits, sweet potatoes, and nectars, and even high-fat foods, such as avocados and nuts. -still, a nutrient-rich diet remains central for ade- quacy s sake. -though vital, energy alone is not enough to support performance. -some athletes use commercial high-carbohydrate liquid supplements to obtain the carbohydrate and energy needed for heavy training and top performance. -these supplements do not replace regular food; they are meant to be used in addi- tion to it. -unlike the sports beverages discussed in the how to on p. 495, these high-carbohydrate supplements are too concentrated in carbohydrate to be used for fluid replacement. -protein in addition to carbohydrate and some fat (and the energy they provide), physically active people need protein. -meats and milk products are rich protein sources, but recommending that active people emphasize these foods is narrow ad- vice. -as mentioned repeatedly, active people need diets rich in carbohydrate, and of course, meats have none to offer. -legumes, whole grains, and vegetables provide some protein with abundant carbohydrate. -table 14-4 (p. 491) shows recommended protein intakes for active people. -a performance diet example a person who engages in vigorous physical ac- tivity on a daily basis could easily require more than 3000 kcalories per day. -to meet this need, the person can choose a variety of nutrient-dense foods. -figure 14-4 (p. 498) shows one example of meals that provide just over 3000 kcalories. -these meals supply about 125 grams of protein, equivalent to the highest recommended intake for an athlete weighing 160 pounds. -obviously, the higher a person s energy intake, the more protein that person will receive, assuming the foods chosen are nu- trient dense. -this relationship between energy and protein intakes breaks down only when people meet their energy needs with high-fat, high-sugar confections. -the meals shown in figure 14-4 provide almost 520 grams of carbohydrate, or over 60 percent of total kcalories. -athletes who train exhaustively for endurance events may want to aim for somewhat higher carbohydrate intakes. -beyond these specific con- cerns of total energy, protein, and carbohydrate, the diet most beneficial to athletic performance is remarkably similar to the diet recommended for most people.60 meals before and after competition no single food improves speed, strength, or skill in competitive events, although some kinds of foods do support performance better than others as already explained. -still, a competitor may eat a particular food before or after an event for psychologi- cal reasons. -one eats a steak the night before wrestling. -another eats some honey just five minutes after diving. -as long as these practices remain harmless, they should be respected. -. -c n i , s o i d u t s l a r a o p carbohydrate recommendation for athletes in heavy training: 8 to 10 g/kg body weight. -a variety of foods is the best source of nutrients for athletes. -498 chapter 14 figure 14-4 an example of an athlete s meal selections this sample menu provides about 3000 kcalories, with almost 520 grams of carbohydrate (63 percent of total kcalories) and about 125 grams of protein (15 percent of total kcalories). -in addition to meeting the carbohydrate and protein needs of an athlete, these meals also meet or exceed recommendations for all vitamin and minerals. ) -l l a ( . -c n i i s o d u t s a r a o p l breakfast 1 c shredded wheat with low-fat milk and banana 2 slices whole-wheat toast with jelly 11/2 c orange juice lunch 2 turkey sandwiches 11/2 c low-fat milk large bunch of grapes snack 3 c plain popcorn a smoothie made from: 11/2 c apple juice 11/2 frozen banana total kcal: about 3000 63% kcal from carbohydrate 22% kcal from fat 15% kcal from protein all vitamin and mineral intakes exceed the rda for both men and women. -dinner salad: 1 c spinach, carrots, and mushrooms with 1/2 c garbanzo beans, 1 tbs sunflower seeds, and 1 tbs ranch salad dressing 1 c spaghetti with meat sauce 1 c green beans 1 corn on the cob 2 slices italian bread 4 tsp butter 1 piece angel food cake with fresh strawberries and whipping cream 1 c low-fat milk pregame meals science indicates that the pregame meal or snack should include plenty of fluids and be light and easy to digest. -it should provide between 300 and 800 kcalories, primarily from carbohydrate-rich foods that are familiar and well tol- erated by the athlete. -the meal should end three to four hours before competition to allow time for the stomach to empty before exertion. -breads, potatoes, pasta, and fruit juices that is, carbohydrate-rich foods low in fat and fiber form the basis of the best pregame meal (see figure 14-5 for some ex- amples). -bulky, fiber-rich foods such as raw vegetables or high-bran cereals, al- figure 14-5 examples of high-carbohydrate pregame meals pregame meals should be eaten three to four hours before the event and provide 300 to 800 kcalories, primarily from carbohydrate- rich foods. -each of these sample meals provides at least 65% of total kcalories from carbohydrate. ) -l l a ( o i g g u r r a f w e h t t a m 300-kcalorie meal 1 large apple 4 saltine crackers 11/2 tbs reduced-fat peanut butter 500-kcalorie meal 1 large whole-wheat bagel 2 tbs jelly 11/2 c low-fat milk 750-kcalorie meal 1 large baked potato 2 tsp margarine 1 c steamed broccoli 1 c mixed carrots and green peas 5 vanilla wafers 11/2 c apple or pineapple juice fitness: physical activity, nutrients, and body adaptations 499 high-carbohydrate, liquid pregame meal ideas: apple juice, frozen banana, and cinnamon papaya juice, frozen strawberries, and mint fat-free milk, frozen banana, and vanilla though usually desirable, are best avoided just before competition. -fiber in the di- gestive tract attracts water and can cause stomach discomfort during performance. -liquid meals are easy to digest, and many such meals are commercially avail- able. -alternatively, athletes can mix fat-free milk or juice, frozen fruits, and flavor- ings in a blender. -postgame meals as mentioned earlier, eating high-carbohydrate foods after physical activity enhances glycogen storage. -because people are usually not hungry immediately following physical activity, carbohydrate-containing beverages such as sports drinks or fruit juices may be preferred. -if an active person does feel hungry after an event, then foods high in carbohydrate and low in protein, fat, and fiber are the ones to choose the same ones recommended prior to competition. -in summary the person who wants to excel physically will apply accurate nutrition knowl- edge along with dedication to rigorous training. -a diet that provides ample fluid and includes a variety of nutrient-dense foods in quantities to meet en- ergy needs will enhance not only athletic performance, but overall health as well. -carbohydrate-rich foods that are light and easy-to-digest are recom- mended for both the pregame and the postgame meal. -training and genetics being equal, who will win a competition the athlete who habitually con- sumes inadequate amounts of needed nutrients or the competitor who arrives at the event with a long history of full nutrient stores and well-met metabolic needs? -some athletes learn that nutrition can support physical performance and turn to pills and powders instead of foods. -in case you need further convincing that a healthful diet surpasses such potions, the following highlight addresses this issue. -nutrition portfolio www.thomsonedu.com/thomsonnow the foods and beverages you eat and drink provide fuel and other nutrients to sup- port your physical activity. -describe your daily physical activities and how they compare with recommenda- tions to be physically active for at least 30 minutes, and preferably 60 minutes, a day on most or all days of the week. -estimate your daily fluid intake, making note of whether you drink fluids, espe- cially water, before, during, and after physical activity. -evaluate the carbohydrate contents of your diet and consider whether it would meet the needs of a physically active person. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 14, then to nutrition on the net. -visit the u.s. government site: www.fitness.gov search for physical fitness at the american college of sports medicine information site: www.acsm.org review the surgeon general s report on physical activity: www.cdc.gov/nccdphp/sgr/sgr.htm review resources offered on the nutrition and physical activity site from the centers for disease control and prevention: www.cdc.gov/nccdphp/dnpa 500 chapter 14 learn about the president s council on physical fitness find fitness information at the cooper institute for aero- and sports: www.presidentschallenge.com bics research: www.cooperinst.org visit shape up america: www.shapeup.org visit the american council on exercise (ace): www.acefitness.org visit the canadian council of sports medicine: www.ccsm.info study questions find information on sports drinks and other nutrition and fitness topics at the gatorade sports science institute site: www.gssiweb.com to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -c. an activity in a different setting. -d. a different activity each day of the week. -3. the process that regenerates glucose from lactate is these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. define fitness, and list its benefits. -(pp. -477 478) 2. explain the overload principle. -(p. 480) 3. define cardiorespiratory conditioning and list some of its benefits. -(p. 482) 4. what types of activity are anaerobic? -which are aerobic? -(pp. -485 487) 5. describe the relationships among energy expenditure, type of activity, and oxygen use. -(p. 485) 6. what factors influence the body s use of glucose during physical activity? -how? -(pp. -485 488) 7. what factors influence the body s use of fat during phys- ical activity? -how? -(pp. -488 490) 8. what factors influence the body s use of protein during physical activity? -how? -(pp. -490 491) 9. why are some athletes likely to develop iron-deficiency anemia? -compare iron-deficiency anemia and sports anemia, explaining the differences. -(pp. -492 493) 10. discuss the importance of hydration during training, and list recommendations to maintain fluid balance. -(pp. -493 496) 11. describe the components of a healthy diet for athletic performance. -(pp. -496 499) known as the: a. cori cycle. -b. atp-cp cycle. -c. adaptation cycle. -d. cardiac output cycle. -4. hitting the wall is a term runners sometimes use to describe: a. dehydration. -b. competition. -c. indigestion. -d. glucose depletion. -5. the technique endurance athletes use to maximize glycogen stores is called: a. aerobic training. -b. muscle conditioning. -c. carbohydrate loading. -d. progressive overloading. -6. conditioned muscles rely less on ____ and more on ____ for energy. -a. protein; fat b. fat; protein c. glycogen; fat d. fat; glycogen 7. vitamin or mineral supplements taken just before an event are useless for improving performance because the: a. athlete sweats the nutrients out during the event. -b. stomach can t digest supplements during physical these multiple choice questions will help you prepare for an exam. -answers can be found on p. 502. activity. -c. nutrients are diluted by all the fluids the athlete 1. physical inactivity is linked to all of the following dis- drinks. -eases except: a. cancer. -b. diabetes. -c. emphysema. -d. hypertension. -2. the progressive overload principle can be applied by performing: a. an activity less often. -b. an activity with more intensity. -d. body needs hours or days for the nutrients to do their work. -8. physically active young women, especially those who are endurance athletes, are prone to: a. energy excess. -b. iron deficiency. -c. protein overload. -d. vitamin a toxicity. -9. the body s need for ____ far surpasses its 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casa, p. m. clarkson, and w. o. roberts, american college of sports medi- cine roundtable on hydration and physical activity: consensus statements, current sports medicine reports 4 (2005): 115-127; committee on dietary reference intakes, dietary reference intakes for water, potassium, sodium, chloride, and sulfate (washington, d.c.: national academies press, 2005), pp. -108-110. -54. c. k. seto, d. way, and n. o connor, envi- ronmental illness in athletes, clinics in sports medicine 24 (2005): 695-718. -55. casa, clarkson, and roberts, 2005. -56. seto, way, and o connor, 2005; j. r. stofan and coauthors, sweat and sodium losses in ncaa division 1 football players with a history of whole-body muscle cramping, presented at the annual meeting of the american college of sports medicine, 2003, unpublished. -57. committee on dietary reference intakes, dietary reference intakes for water, potassium, sodium, chloride, and sulfate (washington, d.c.: national academies press, 2005), pp.127-132. -58. m. hsieh and coauthors, hyponatremia in runners requiring on-site medical treatment at a single marathon, medicine and science in sports and exercise 34 (2002): 185-189. -59. e. r. eichner, exertional hyponatremia: why so many women? -sports medicine digest 24 (2002): 54, 56. -60. position of the american dietetic associa- tion, dietitians of canada, and the ameri- can college of sports medicine, 2000. highlight 14 highlight supplements as ergogenic aids athletes gravitate to promises that they can enhance their performance by taking pills, powders, or potions. -unfortunately, they of- ten hear such promises from their coaches and peers, who advise them to use nutrient supplements, take drugs, or follow proce- dures that claim to deliver results with little ef- fort.1 when such performance-enhancing aids are harmless, they are only a waste of money; when they im- pair performance or harm health, they waste athletic potential and cost lives. -this highlight looks at some promises of magic to enhance physical performance. -ergogenic aids many substances or treatments claim to be ergogenic, meaning work enhancing. -the glossary below defines several of the com- monly used ergogenic aids discussed in this highlight. -the glos- sary on p. 504 presents additional substances promoted as ergogenic aids. -for the large majority of these substances, re- search findings do not support those claims.2 athletes who hear that a product is ergogenic should ask who is making the claim and who will profit from the sale. -sometimes it is difficult to distinguish valid claims from bogus ones. -fitness magazines and internet websites are particularly trouble- some because many of them present both valid and invalid nutrition i s e g a m n e l l e y t t e g / e n o t s / g g a t s information along with slick advertisements for nutrition products. -advertisements often feature colorful anatomical figures, graphs, and tables that appear scientific. -some ads even include ref- erences, citing or linking to such credible sources as the american journal of clinical nutrition and the journal of the american medical association. -these ads create the illusion of endorsement and credibility to gain readers trust. -keep in mind, however, that the ads are created not to teach, but to sell. -a careful reading of the cited re- search might reveal that the ads have presented the research findings out of context.3 in one such case, an ad cited a research article to sup- port the invalid conclusion that its human growth hormone supple- ment increases lean body mass and bone mineral. -researchers reporting in the cited article had reached another conclusion: its gen- eral use now or in the immediate future is not justified. -scientific facts had been exaggerated and twisted to promote sales. -highlight 1 de- scribed ways to recognize misinformation and quackery. -dietary supplements a variety of supplements make claims based on misunderstood nutrition principles. -the claims may sound good, but for the most part, they have little or no factual basis. -chapter 6 included a dis- cussion on protein powders and amino acid supplements (pp. -202 203). -g lossary the glossary on p. 504 includes additional supplements commonly used to enhance performance. -anabolic steroids: drugs related to the male sex hormone, testosterone, that stimulate the development of lean body mass. -anabolic (cid:6) promoting growth sterols (cid:6) compounds chemi- cally related to cholesterol caffeine: a natural stimulant found in many common foods and beverages, including coffee, tea, and chocolate; may enhance endurance by stimulating fatty acid release. -high doses cause headaches, trembling, rapid heart rate, and other undesirable side effects. -chromium picolinate (crow- mee-um pick-oh-lyn-ate): a trace mineral supplement; falsely promoted as building muscle, enhancing energy, and burning fat. -picolinate is a derivative of the amino acid tryptophan that seems to enhance chromium absorption. -creatine (kree-ah-tin): a nitrogen-containing compound that combines with phosphate to form the high-energy compound creatine phosphate (or phosphocreatine) in muscles. -claims that creatine enhances energy use and muscle strength need further confirmation. -dhea (dehydroepiandrosterone) and androstenedione: hormones made in the adrenal glands that serve as precursors to the male hormone testosterone; falsely promoted as burning fat, building muscle, and slowing aging. -side effects include acne, aggressiveness, and liver enlargement. -ergogenic (er-go-jen-ick) aids: substances or techniques used in an attempt to enhance physical performance. -ergo (cid:6) work genic (cid:6) gives rise to hgh (human growth hormone): a hormone produced by the brain s pituitary gland that regulates normal growth and development; also called somatotropin. -some athletes misuse this hormone to increase their height and strength. -reminders: carnitine is a nonessential nonprotein amino acid made in the body from lysine that helps transport fatty acids across the mitochondrial membrane. -carnitine supposedly burns fat and spares glycogen during endurance events, but in reality it does neither. -conjugated linoleic acid is a naturally occuring trans fatty acid with 18 carbons and 2 double bonds; sometimes taken as a supplement to improve body composition. -503 504 highlight 14 g lossary of substances promoted as ergogenic aides the glossary on p. 503 includes supplements mentioned in the text. -chapter 6 includes a discussion on protein and amino acid supplements (pp. -202 203). -arginine: a nonessential amino acid falsely promoted as enhancing the secretion of human growth hormone, the breakdown of fat, and the development of muscle. -boron: a nonessential mineral that is promoted to increase muscle mass. -coenzyme q10: a lipid found in cells (mitochondria) shown to improve exercise performance in heart disease patients, but not effective in improving the performance of healthy athletes. -gamma-oryzanol: a plant sterol that supposedly provides the same physical responses as anabolic steroids without the adverse side effects; also known as ferulic acid, ferulate, or frac. -ginseng: a plant whose extract supposedly boosts energy. -side effects of chronic use include nervousness, confusion, and depression. -hmb (beta-hydroxy-beta- methylbutyrate): a metabolite of the branched-chain amino acid leucine. -claims that hmb increases muscle mass and strength are based on the results of two studies from the lab that developed hmb as a supplement. -pyruvate: a 3-carbon compound that plays a key role in energy metabolism. -supplements claim to burn fat and enhance performance. -ribose: a 5-carbon sugar falsely promoted as improving the regeneration of atp and thereby the speed of recovery after high- power exercise. -royal jelly: the substance produced by worker bees and fed to the queen bee; falsely promoted as increasing strength and enhancing performance. -sodium bicarbonate: baking soda; an alkaline salt believed to neutralize blood lactic acid and thereby to reduce pain and enhance possible workload. -soda loading may cause intestinal bloating and diarrhea. -spirulina: a kind of alga ( blue- green manna ) that supposedly contains large amounts of protein and vitamin b12, suppresses appetite, and improves athletic performance. -it does none of these things and is potentially toxic. -carnitine carnitine, a nonessential nutrient, is often promoted as a fat burner. -some athletes use it, hoping carnitine will help them burn more fat, thereby sparing glycogen during endurance events. -in the body, carnitine facilitates the transfer of fatty acids across the mitochondrial membrane. -supplement manufacturers suggest that with more carnitine available, fat oxidation will be enhanced, but this does not seem to be the case. -carnitine supplementation neither raises muscle carnitine concentrations nor enhances exercise performance.4 it does, however, produce diarrhea in about half of the people who use it. -milk and meat products are good sources of carnitine, and supplements are not needed. -chromium picolinate chapter 13 introduced chromium as an essential trace mineral in- volved in carbohydrate and lipid metabolism. -advertisements in bodybuilding magazines claim that chromium picolinate, which is more easily absorbed than chromium alone, builds mus- cle, enhances energy, and burns fat. -such claims derive from one or two initial studies reporting that men who weight trained while taking chromium picolinate supplements increased lean body mass and reduced body fat. -most subsequent studies, how- ever, show no effects of chromium picolinate supplementation on strength, lean body mass, or body fat.5 in fact, some research suggests that chromium picolinate supplements promote oxida- tive damage to lipids and dna.6 other forms of chromium sup- plements, such as chromium chloride, do not seem to have this effect and are thus gaining popularity. -complete nutrition supplements several drinks and candy bars appeal to athletes by claiming to pro- vide complete nutrition. -these products usually taste good and provide extra food energy, but they fall short of providing com- plete nutrition. -they can be useful as a pregame meal or a be- tween-meal snack, but they should not replace regular meals. -a nutritionally complete drink may help a nervous athlete who cannot tolerate solid food on the day of an event. -a liquid meal two or three hours before competition can supply some of the fluid and carbohydrate needed in a pregame meal, but a shake of fat-free milk or juice (such as apple or papaya) and ice milk or frozen fruit (such as strawberries or bananas) can do the same thing less expensively. -creatine interest in and use of creatine supplements to enhance per- formance during intense activity has grown dramatically in the last few years. -power athletes such as weight lifters use creatine supplements to enhance stores of the high-energy compound creatine phosphate (cp) in muscles. -theoretically, the more crea- tine phosphate in muscles, the higher the intensity at which an athlete can train. -high-intensity training stimulates the muscles to adapt, which, in turn, improves performance. -the results of some studies suggest that creatine supplementa- tion does enhance performance of short-term, repetitive, high- intensity activity such as weight lifting or sprinting.7 creatine may improve performance by increasing muscle strength and size, cell hydration, or glycogen loading capacity.8 in contrast, creatine sup- plemention has not been shown to benefit endurance activity.9 the question of whether short-term use of creatine supple- ments is safe continues to be studied, but so far, the supplements are viewed to be safe for healthy adults.10 in a study of 23 football players, long-term use (21 months) of creatine supplements re- vealed no adverse effects on kidney or liver function.11 more re- search is needed, however, to confirm the safety of long-term creatine use. -creatine supplementation may pose risks to athletes with kidney disease or other conditions. -one side effect of crea- tine supplementation that no one disputes is weight gain. -for some athletes, weight gain, especially muscle gain, is beneficial, but for others, it is not. -some medical and fitness experts voice concern that, like many performance enhancement supplements before it, creatine is being taken in huge doses (5 to 30 grams per day) before evi- dence of its value has been ascertained. -even people who eat red meat, which is a creatine-rich food, do not consume nearly the amount supplements provide. -(creatine content varies, but on average, pork, chicken, and beef provide 65 to 180 milligrams per ounce.) -despite the uncertainties, creatine supplements are not illegal in international competition. -the american academy of pediatrics strongly discourages the use of creatine supple- ments, as well as the use of any performance-enhancing sub- stance in adolescents less than 18 years old.12 conjugated linoleic acid conjugated linoleic acid (cla) derives from the essential fatty acid, linoleic acid. -cla is part of a group of naturally occur- ring polyunsaturated fatty acids found in beef, lamb, and dairy products. -in animal studies, cla has been shown to reduce body fat and increase lean body mass findings that have sparked in- terest in cla as a performance-enhancing aid.13 only a few stud- ies on the effects of supplemental cla on body composition in human beings have been conducted, however, and the results seem less promising.14 when researchers studied the combined effects of supplemental cla and resistance training on body com- position in men and women, they found small increases in lean body mass and reductions in body fat but no improvements in strength.15 the researchers noted that although the effects were statistically significant, they were nevertheless small and should be weighed against the relatively high cost of supplemental cla. -caffeine some research supports the use of caffeine to enhance endurance and, to some extent, to enhance short-term, high-intensity exercise performance.16 caffeine may stimulate fatty acid release during en- durance activity, but in contrast to what was previously thought, caffeine does not slow muscle glycogen use. -light activity before a workout also stimulates fat release, but in addition, the activity warms the muscles and connective tissues, making them flexible and resistant to injury. -caffeine does not offer these added benefits. -caffeine is a stimulant that elicits a number of physiological and psychological effects in the body. -caffeine enhances alertness and reduces fatigue.17 the possible benefits of caffeine use must be weighed against its adverse effects stomach upset, nervous- ness, irritability, headaches, and diarrhea. -caffeine-containing bev- erages should be used in moderation, if at all, and in addition to other fluids, not as a substitute for them. -college, national, and in- ternational athletic competitions prohibit the use of caffeine in amounts greater than the equivalent of 5 to 6 cups of coffee con- sumed in a two-hour period prior to competition. -urine tests that detect more caffeine than this disqualify athletes from competition. -(the table at the start of appendix h provides a list of common caffeine-containing items and the doses they deliver.) -oxygenated water oxygenated water water infused with oxygen claims to im- prove athletic performance, increase endurance, and sharpen concentration by delivering extra oxygen to the muscles. -what s wrong with this claim? -one thing wrong is the assumption that supplements as ergogenic aids 505 oxygen can enter the bloodstream by way of the gi tract which it can t. another thing wrong is the assumption that the body can use more oxygen than it receives from the lungs which it can t. the only time athletes might benefit from oxygen (inhaled, not swallowed) might be when exercising at elevations higher than they are accustomed to. -any benefits of oxygenated water come from the water, not the oxygen. -hormonal supplements the dietary supplements discussed this far may or may not help athletic performance, but in the doses commonly taken, they seem to cause little harm. -the remaining discussion features sup- plements that are clearly damaging. -anabolic steroids among the most dangerous and illegal ergogenic practices is the taking of anabolic steroids. -these drugs are derived from the male sex hormone testosterone, which promotes the develop- ment of male characteristics and lean body mass. -the athletes who take steroids do so to stimulate muscle bulking. -to athletes struggling to excel, the promise of bigger, stronger muscles than training alone can produce is tempting. -athletes who lack superstar genetic material and who normally would not be able to break into the elite ranks can, with the help of steroids, suddenly compete with true champions. -especially in professional circles such as major league baseball and the national football league, where monetary rewards for excellence are sky-high, steroid use is common despite its illegality and side effects. -the american academy of pediatrics and the american col- lege of sports medicine condemn athletes use of anabolic steroids, and the international olympic committee bans their use. -these authorities cite the known toxic side effects and main- tain that taking these drugs is a form of cheating. -other athletes are put in the difficult position of either conceding an unfair ad- vantage to competitors who use steroids or taking them and ac- cepting the risk of harmful side effects (see table h14-1, p. 506). -young athletes should not be forced to make such a choice. -the price for the potential competitive edge that steroids confer is high sometimes it is life itself. -steroids are not simple pills that build bigger muscles. -they are complex chemicals to which the body reacts in many ways, particularly when bodybuilders and other athletes take large amounts.18 the safest, most effective way to build muscle has always been through hard training and a sound diet, and despite popular misconceptions it still is. -some manufacturers peddle specific herbs as legal substitutes for steroid drugs. -they falsely claim that these herbs contain hor- mones, enhance the body s hormonal activity, or both. -in some cases, an herb may contain plant sterols, such as gamma- oryzanol, but these compounds are poorly absorbed. -even if ab- sorption occurs, the body cannot convert herbal compounds to anabolic steroids. -none of these products has any proven anabolic steroid activity, none enhances muscle strength, and some contain natural toxins. -in short, natural does not mean harmless. -506 highlight 14 table h14-1 and adverse reactions anabolic steroids: side effects mind extreme aggression with hostility ( steroid rage ); mood swings; anxiety; dizziness; drowsiness; unpredictability; insomnia; psychotic depression; personality changes, suicidal thoughts face and hair swollen appearance; greasy skin; severe, scarring acne; mouth and tongue soreness; yellowing of whites of eyes (jaundice) in females, male-pattern hair loss and increased growth of face and body hair voice in females, irreversible deepening of voice chest in males, breathing difficulty, breast development in females, breast atrophy heart heart disease; elevated or reduced heart rate; heart attack; stroke; hypertension; increased ldl; reduced hdl abdominal organs nausea; vomiting; bloody diarrhea; pain; edema; liver tumors (possibly cancerous); liver damage, disease, or rupture leading to fatal liver failure; kidney stones and damage; gallstones; frequent urination; possible rupture of aneurysm or hemorrhage blood blood clots; high risk of blood poisoning; those who share needles risk contracting hiv (the aids virus) or other disease-causing organisms; septic shock (from injections) reproductive system in males, permanent shrinkage of testes; prostate enlargement with increased risk of cancer; sexual dysfunction; loss of fertility; excessive and painful erections in females, loss of menstruation and fertility; permanent enlargement of external genitalia; fetal damage, if pregnant muscles, bones, and connective tissues increased susceptibility to injury with delayed recovery times; cramps; tremors; seizurelike movements; injury at injection site in adolescents, failure to grow to normal height other fatigue; increased risk of cancer dhea and androstenedione some athletes use dhea and androstenedione as alternatives to anabolic steroids. -androstenedione made headlines in the late 1990s when the media reported that baseball great mark mc- gwire had been using it. -dhea (dehydroepiandrosterone) and an- drostenedione are hormones made in the adrenal glands that serve as precursors to the male hormone testosterone. -advertise- ments claim the hormones burn fat, build muscle, and slow aging, but evidence to support such claims is lacking. -short-term side effects of dhea and androstenedione may in- clude oily skin, acne, body hair growth, liver enlargement, testic- ular shrinkage, and aggressive behavior. -long-term effects, such as serious liver damage may take years to become evident. -the potential for harm from dhea and androstenedione supplements is great, and athletes, as well as others, should avoid them. -recently, the food and drug administration (fda) sent letters to producers of dietary supplements warning that products con- taining androstenedione are considered to be adulterated, and therefore illegal to sell, and that criminal penalties could result from continued sales. -the national collegiate athletic associa- tion, the national football league, and the international olympic committee have banned the use of androstenedione and dhea in competition. -the american academy of pediatrics and many other medical professional groups have spoken out against the use of these and other hormone replacement substances. -human growth hormone some short or average-sized athletes sometimes use hgh (hu- man growth hormone) to build lean tissue and increase their height if they are still in their growing years. -athletes in power sports such as weight lifting and judo are most likely to experi- ment with hgh, believing the injectable hormone will provide the benefits of anabolic steroids without the dangerous side effects. -taken in large quantities, hgh causes the disease acromegaly, in which the body becomes huge and the organs and bones over- enlarge. -other effects include diabetes, thyroid disorder, heart dis- ease, menstrual irregularities, diminished sexual desire, and shortened life span. -the u.s. olympic committee bans hgh use, but tests cannot definitively distinguish between naturally occur- ring hgh and hgh used as a drug.19 the committee maintains that the use of hgh is a form of cheating that undermines the quest for physical excellence and that its use is coercive to other athletes. -the search for a single food, nutrient, drug, or technique that will safely and effectively enhance athletic performance will no doubt continue as long as people strive to achieve excellence in sports. -when athletic performance does improve after use of an er- gogenic aid, the improvement can often be attributed to the placebo effect, which is strongly at work in athletes. -even if a reli- able source reports a performance boost from a newly tried prod- uct, give the effect time to fade away. -chances are excellent that it simply reflects the power of the mind over the body. -the overwhelming majority of performance-enhancing aids sold for athletes are frauds. -wishful thinking will not substitute for talent, hard training, adequate diet, and mental preparedness in competition. -but don t discount the power of mind over body for a minute it is formidable, and sports psychologists dedicate their work to harnessing it. -you can use it by imagining yourself a win- ner and visualizing yourself excelling in your sport. -you don t have to buy magic to obtain a winning edge; you already possess it your physically fit mind and body. -supplements as ergogenic aids 507 nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 14, then to highlights nutrition on the net. -find information on sports drinks and other nutrition and fitness topics at the gatorade sports science institute site: www.gssiweb.com references 1. k. a. erdman, t. s. fung, and r. a. reimer, influence of performance level on dietary supplementation in elite canadian athletes, medicine and science in sports and exercise 38 (2006): 349 356. -2. f. brouns and coauthors, functional foods and food supplements for athletes: from myths to benefit claims substantiation through the study of selected biomarkers, british journal of nutrition 88 (2002): s177 s186. -3. j. m. drazen, inappropriate advertising of dietary supplements, new england journal of medicine 348 (2003): 777 778. -4. e. m. broad, r. j. maughan, s. d. galloway, effects of four weeks l-carnitine l-tartrate ingestion on substrate utilization during prolonged exercise, international journal of sport nutrition and exercise metabolism 15 (2005): 665 679; e. p. brass, carnitine and sports medicine: use or abuse? -annals of the new york academy of sciences 1033 (2004): 67 78. -5. j. b. vincent, the potential value and toxic- ity of chromium picolinate as a nutritional supplement, weight loss agent and muscle development agent, sports medicine 33 (2003): 213 230. -6. vincent, 2003. -7. m. c. peyrebrune and coauthors, effect of creatine supplementation on training for competition in elite swimmers, medicine and science in sports and exercise 37 (2005): 2140 2147; r. l. dempsey, m. f. mazzone, and l. n. meurer, does oral creatine supple- mentation improve strength? -a meta- analysis, journal of family practice 51 (2002): 945 951; j. s. volek and coauthors, physio- logical responses to short-term exercise in the heat after creatine loading, medicine and science in sports and medicine 33 (2001): 1101 1108; d. preen and coauthors, effect of creatine loading on long-term sprint exercise performance and metabolism, medicine and science in sports and medicine 33 (2001): 814 821. -8. p. d. chilibeck and coauthors, effect of creatine ingestion after exercise on muscle thickness in males and females, medicine and science in sports and exercise 36 (2004): 1781 1788; a. g. nelson, muscle glycogen supercompensation is enhanced by prior creatine supplementation, medicine and science in sports and medicine 33 (2001): 1096 1100; m. g. bemben and coauthors, creatine supplementation during resistance training in college football athletes, medicine and science in sports and medicine 33 (2001): 1667 1673; d. willoughby and j. rosene, effects of oral creatine and resistance train- ing on myosin heavy chain expression, medicine and science in sports and medicine 33 (2001): 1674 1681. -9. t. l. schwenk and c. d. costley, when food becomes a drug: nonanabolic nutritional supplement use in athletes, the american journal of sports medicine 30 (2003): 907 916. -10. m. dunford and m. smith, dietary supple- ments and ergogenic aids, in sports nutri- tion: a practice manual for professionals, 4th ed., ed. -m. dunford (chicago: american dietetic association, 2006), pp. -116 141; e. bizzarini and l. de angelis, is the use of oral creatine supplementation safe? -journal of sports medicine and physical fitness 44 (2004): 411 416. -11. r. b. kreider and coauthors, long-term creatine supplementation does not signifi- cantly affect clinical markers of health in athletes, molecular and cellular biochemistry 244 (2003): 95 104. -12. american academy of pediatrics, policy statement, committee on sports medicine and fitness, use of performance-enhancing substances, pediatrics 115 (2005): 1103 1106. -13. a. m. bhattacharya and coauthors, the combination of dietary conjugated linoleic acid and treadmill exercise lowers gain in body fat mass and enhances lean body mass in high fat-fed male balb/c mice, journal of nutrition 135 (2005): 1124 1130; m. a. belury, dietary conjugated linoleic acid in health: physiological effects and mecha- nisms of action, annual review of nutrition 22 (2002): 505 531. -14. a. h. m. terpstra, effect of conjugated linoleic acid on body composition and plasma lipids in humans: an overview of the literature, american journal of clinical nutrition 79 (2004): 352 361. -15. c. pinkoski and coauthors, the effects of conjugated linoleic acid supplementation during resistance training, medicine and science in sports and exercise 38 (2006): 339 348. -16. k. t. schneiker and coauthors, effects of caffeine on prolonged intermittent-sprint ability in team-sport athletes, medicine and science in sports and exercise 38 (2006): 578 585; g. r. stuart and coauthors, multi- ple effects of caffeine on simulated high- intensity team-sport performance, medicine and science in sports and exercise 37 (2005): 1998 2005; s. a. paluska, caffeine and exercise, current sports medicine reports 2 (2003): 213 219. -17. stuart and coauthors, 2005; paluska, 2003. -18. a. b. parkinson and n. a. evans, anabolic androgenic steroids: a survey of 500 users, medicine and science in sports and exercise 38 (2006): 644 651. -19. l. di luigi and l. guidetti, igf-1, igfbp-2, and -3: do they have a role in detecting rhgh abuse in trained men? -medicine and science in sports and medicine 34 (2002): 1270 1278. mary ellen bartley/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow food choices have consequences. -sometimes they happen immediately, as when you get heartburn after eating a pepperoni and jalape o pizza. -other times they sneak up on you, as when you gain weight after repeatedly nutrition portfolio journal overindulging in double hot fudge sundaes. -quite often, they are temporary and easily resolved, as when hunger pangs strike after you drink only a diet cola for lunch. -during pregnancy, however, the consequences of a woman s food choices are dramatic. -they affect not just her health, but also the growth and development of another human being and not just for today, but for years to come. -making smart food choices is a huge responsibility, but fortunately, it s fairly simple. -c h a p t e r 15 chapter outline nutrition prior to pregnancy growth and development during pregnancy placental development fetal growth and development critical periods maternal weight weight prior to conception weight gain during pregnancy exercise during pregnancy nutrition during pregnancy energy and nutrient needs during pregnancy vegetarian diets during pregnancy and lactation common nutrition-related concerns of pregnancy high-risk pregnancies the infant s birthweight malnutrition and pregnancy food assistance programs maternal health the mother s age practices incompatible with pregnancy nutrition during lactation lac- tation: a physiological process breast- feeding: a learned behavior maternal energy and nutrient needs during lactation maternal health practices incompatible with lactation highlight 15 fetal alcohol syndrome life cycle nutrition: pregnancy and lactation all people pregnant and lactating women, infants, children, adolescents, and adults need the same nutrients, but the amounts they need vary de- pending on their stage of life. -this chapter focuses on nutrition in prepara- tion for, and support of, pregnancy and lactation. -the next two chapters address the needs of infants, children, adolescents, and older adults. -nutrition prior to pregnancy a section on nutrition prior to pregnancy must, by its nature, focus mainly on women. -both a man s and a woman s nutrition may affect fertility and possibly the genetic contributions they make to their children, but it is the woman s nutrition that has the most direct influence on the developing fetus. -her body provides the en- vironment for the growth and development of a new human being. -prior to preg- nancy, a woman has a unique opportunity to prepare herself physically, mentally, and emotionally for the many changes to come. -in preparation for a healthy preg- nancy, a woman can establish the following habits:1 achieve and maintain a healthy body weight. -both underweight and overweight are associated with infertility.2 overweight and obese men have low sperm counts and hormonal changes that reduce fertility.3 excess body fat in women disrupts menstrual regularity and ovarian hormone production.4 should a pregnancy occur, mothers, both underweight and overweight, and their newborns, face increased risks of complications. -choose an adequate and balanced diet. -malnutrition reduces fertility and im- pairs the early development of an infant should a woman become pregnant. -be physically active. -a woman who wants to be physically active when she is pregnant needs to become physically active beforehand. -receive regular medical care. -regular health care visits can help ensure a healthy start to pregnancy. -manage chronic conditions. -diseases such as diabetes, hiv/aids, pku, and sexually transmitted diseases can adversely affect a pregnancy and need close medical attention to help ensure a healthy outcome. -fertility: the capacity of a woman to produce a normal ovum periodically and of a man to produce normal sperm; the ability to reproduce. -509 510 chapter 15 young adults can prepare for a healthy preg- nancy by taking care of themselves today. -conception: the union of the male sperm and the female ovum; fertilization. -placenta (plah-sen-tuh): the organ that develops inside the uterus early in pregnancy, through which the fetus receives nutrients and oxygen and returns carbon dioxide and other waste products to be excreted. -uterus (you-ter-us): the muscular organ within which the infant develops before birth. -amniotic (am-nee-ott-ic) sac: the bag of waters in the uterus, in which the fetus floats. -umbilical (um-bill-ih-cul) cord: the ropelike structure through which the fetus s veins and arteries reach the placenta; the route of nourishment and oxygen to the fetus and the route of waste disposal from the fetus. -the scar in the middle of the abdomen that marks the former attachment of the umbilical cord is the umbilicus (um-bill-ih- cus), commonly known as the belly button. -ovum (oh-vum): the female reproductive cell, capable of developing into a new organism upon fertilization; commonly referred to as an egg. -sperm: the male reproductive cell, capable of fertilizing an ovum. -zygote (zy-goat): the product of the union of ovum and sperm; so-called for the first two weeks after fertilization. -implantation: the stage of development in which the zygote embeds itself in the wall of the uterus and begins to develop; occurs during the first two weeks after conception. -avoid harmful influences. -both maternal and paternal ingestion of harmful substances (such as cigarettes, alcohol, drugs, or environmental contami- nants) can cause abnormalities, alter genes or their expression, and inter- fere with fertility. -young adults who nourish and protect their bodies do so not only for their own sakes, but also for future generations.5 i s b r o c / . -c n i , z e a l e p . -i e s o j dietary guidelines for americans 2005 women of childbearing age who may become pregnant should eat foods high in heme-iron and/or consume iron-rich plant foods or iron- fortified foods with an enhancer of iron absorption, such as vitamin c- rich foods. -women of childbearing age who may become pregnant should consume adequate synthetic folate daily from fortified foods or supplements in addition to naturally oc- curring folate from a variety of foods. -growth and development during pregnancy a whole new life begins at conception. -organ systems develop rapidly, and nutri- tion plays many supportive roles. -this section describes placental development and fetal growth, paying close attention to times of intense developmental activity. -placental development in the early days of pregnancy, a spongy structure known as the placenta develops in the uterus. -two associated structures also form (see figure 15-1). -one is the am- niotic sac, a fluid-filled balloonlike structure that houses the developing fetus. -the other is the umbilical cord, a ropelike structure containing fetal blood vessels that extends through the fetus s belly button (the umbilicus) to the placenta. -these three structures play crucial roles during pregnancy and then are expelled from the uterus during childbirth. -the placenta develops as an interweaving of fetal and maternal blood vessels embedded in the uterine wall. -the maternal blood transfers oxygen and nutrients to the fetus s blood and picks up fetal waste products. -by exchanging oxygen, nu- trients, and waste products, the placenta performs the respiratory, absorptive, and excretory functions that the fetus s lungs, digestive system, and kidneys will provide after birth. -the placenta is a versatile, metabolically active organ. -like all body tissues, the placenta uses energy and nutrients to support its work. -like a gland, it produces an array of hormones that maintain pregnancy and prepare the mother s breasts for lactation (making milk). -a healthy placenta is essential for the developing fetus to attain its full potential.6 fetal growth and development fetal development begins with the fertilization of an ovum by a sperm. -three stages follow: the zygote, the embryo, and the fetus (see figure 15-2). -the zygote the newly fertilized ovum, or zygote, begins as a single cell and di- vides to become many cells during the days after fertilization. -within two weeks, the zygote embeds itself in the uterine wall a process known as implantation. -cell di- vision continues as each set of cells divides into many other cells. -as development proceeds, the zygote becomes an embryo. -life cycle nutrition: pregnancy and lactation 511 figure 15-1 the placenta and associated structures to understand how placental villi absorb nutrients without maternal and fetal blood interacting directly, think of how the intestinal villi work. -the gi side of the intestinal villi is bathed in a nutrient-rich fluid (chyme). -the intestinal villi absorb the nutrient molecules and release them into the body via capillaries. -similarly, the maternal side of the placental villi is bathed in nutrient-rich maternal blood. -the placental villi absorb the nutrient molecules and release them to the fetus via fetal capillaries. -the arrows indicate the direction of blood flow. -pool of mother's blood fetal vein fetal artery umbilical cord uterine wall placenta umbilical cord umbilical vein umbilical arteries amniotic sac in the placenta, maternal blood vessels lie side by side with fetal blood vessels that reach the fetus through the umbilical cord. -fetal portion of placenta maternal portion of placenta figure 15-2 stages of embryonic and fetal development 1 a newly fertilized ovum is about the size of a period at the end of this sentence. -this zygote at less than one week after fertilization is not much bigger and is ready for implantation. -2 after implantation, the placenta develops and begins to provide nourishment to the developing embryo. -an embryo 5 weeks after fertilization is about 1/2 inch long. -i l l e n n a v . -m y n o h t n a ) 3 , 2 , 1 ( . -c n i s r e h c r a e s e r o t o h p / e l t s e n / t a m r o f t i t e p fingerlike projections (called placental villi) contain fetal blood vessels and extend into the pool of mother s blood. -no actual mingling of fetal and maternal blood occurs, but substances pass back and forth. -thus, oxygen and nutrients from the mother s blood enter fetal vessels, and waste products are removed. -mother s veins carry fetal wastes away. -mother s arteries bring fresh blood with oxygen and nutrients to the fetus. -3 a fetus after 11 weeks of development is just over an inch long. -notice the umbilical cord and blood vessels connecting the fetus with the placenta. -4 a newborn infant after nine months of development measures close to 20 inches in length. -from 8 weeks to term, this infant grew 20 times longer and 50 times heavier. -512 chapter 15 figure 15-3 periods in fetal development the concept of critical critical periods occur early in fetal development. -an adverse influence felt early in pregnancy can have a much more severe and prolonged impact than one felt later on. -an adverse influence felt late temporarily impairs development, but a full recovery is possible. -normal development an adverse influence felt early permanently impairs development, and a full recovery never occurs. -critical period time reminder: the neural tube is the structure that eventually becomes the brain and spinal cord. -embryo (em-bree-oh): the developing infant from two to eight weeks after conception. -fetus (feet-us): the developing infant from eight weeks after conception until term. -critical periods: finite periods during development in which certain events occur that will have irreversible effects on later developmental stages; usually a period of rapid cell division. -gestation (jes-tay-shun): the period from conception to birth. -for human beings, the average length of a healthy gestation is 40 weeks. -pregnancy is often divided into three- month periods, called trimesters. -the embryo the embryo develops at an amazing rate. -at first, the number of cells in the embryo doubles approximately every 24 hours; later the rate slows, and only one doubling occurs during the final 10 weeks of pregnancy. -at 8 weeks, the 11/4-inch embryo has a complete central nervous system, a beating heart, a digestive system, well-defined fingers and toes, and the beginnings of facial features. -the fetus the fetus continues to grow during the next 7 months. -each organ grows to maturity according to its own schedule, with greater intensity at some times than at others. -as figure 15-2 (p. 511) shows, fetal growth is phenomenal: weight increases from less than an ounce to about 71/2 pounds (3500 grams). -most success- ful pregnancies last 38 to 42 weeks and produce a healthy infant weighing between 61/2 and 9 pounds. -critical periods times of intense development and rapid cell division are called critical periods critical in the sense that those cellular activities can occur only at those times. -if cell division and number are limited during a critical period, full recovery is not possible (see figure 15-3). -the development of each organ and tissue is most vulnerable to adverse influ- ences (such as nutrient deficiencies or toxins) during its own critical period (see fig- ure 15-4). -the critical period for neural tube development, for example, is from 17 to 30 days gestation. -consequently, neural tube development is most vulnera- ble to nutrient deficiencies, nutrient excesses, or toxins during this critical time when most women do not even realize that they are pregnant. -any abnormal development of the neural tube or its failure to close completely can cause a major defect in the central nervous system. -figure 15-5 shows photos of neural tube devel- opment in the early weeks of gestation. -figure 15-4 critical periods of development during embryonic development (from 2 to 8 weeks), many of the tissues are in their critical periods (purple area of the bars); events occur that will have irreversible effects on the development of those tissues. -in the later stages of development (green area of the bars), the tissues continue to grow and change, but the events are less critical in that they are relatively minor or reversible. -key: critical development continued development central nervous system heart ears eyes legs and arms teeth palate e u s s t i external genitalia 0 2 zygote 4 embryo 8 12 16 term fetus weeks of gestation source: adapted from before we are born: essentials of embryology and birth defects by k. l. moore. -and t. v. n. persaud: w. b. saunders, 2003. life cycle nutrition: pregnancy and lactation 513 figure 15-5 neural tube development the neural tube is the beginning structure of the brain and spinal cord. -any fail- ure of the neural tube to close or to develop normally results in central nervous system disorders such as spina bifida and anencephaly. -successful development of the neural tube depends, in part, on the vitamin folate. -n, r o b s i d l i h c a m o r f , b a g a l r f s r e i n n o b t r e b l a / n o s s l i n t r a n n e l ) h t o b ( . -o c g n i h s i l b u p l l e d at 4 weeks, the neural tube has yet to close (notice the gap at the top). -at 6 weeks, the neural tube (outlined by the delicate red vertebral arteries) has successfully closed. -neural tube defects in the united states, approximately 30 of every 100,000 newborns are born with a neural tube defect; some 1000 or so infants are affected each year. -* many other pregnancies with neural tube defects end in abortions or stillbirths. -the two most common types of neural tube defects are anencephaly and spina bifida. -in anencephaly, the upper end of the neural tube fails to close. -conse- quently, the brain is either missing or fails to develop. -pregnancies affected by anencephaly often end in miscarriage; infants born with anencephaly die shortly after birth. -spina bifida is characterized by incomplete closure of the spinal cord and its bony encasement (see figure 15-6 on p. 514). -the meninges membranes covering the spinal cord often protrude as a sac, which may rupture and lead to meningitis, a life-threatening infection. -spina bifida is accompanied by varying degrees of paralysis, depending on the extent of the spinal cord damage. -mild cases may not even be noticed, but severe cases lead to death. -common problems include club- foot, dislocated hip, kidney disorders, curvature of the spine, muscle weakness, mental handicaps, and motor and sensory losses. -the cause of neural tube defects is unknown, but researchers are examining sev- eral gene-gene, gene-nutrient, and gene-environment interactions.7 a pregnancy affected by a neural tube defect can occur in any woman, but these factors make it more likely: a previous pregnancy affected by a neural tube defect maternal diabetes (type 1) maternal use of antiseizure medications maternal obesity exposure to high temperatures early in pregnancy (prolonged fever or hot- tub use) race/ethnicity (more common among whites and hispanics than others) low socioeconomic status folate supplementation reduces the risk. -* worldwide, some 300,000 to 400,000 infants are born with neural tube defects each year. -reminder: a neural tube defect is a malfor- mation of the brain, spinal cord, or both during embryonic development. -the two main types of neural tube defects are spina bifida (literally, split spine ) and anencephaly ( no brain ). -anencephaly (an-en-sef-a-lee): an uncommon and always fatal type of neural tube defect; characterized by the absence of a brain. -an = not (without) encephalus = brain spina (spy-nah) bifida (biff-ih-dah): one of the most common types of neural tube defects; characterized by the incomplete closure of the spinal cord and its bony encasement. -spina = spine bifida = split 514 chapter 15 figure 15-6 spina bifida spina bifida, a common neural tube defect, occurs when the vertebrae of the spine fail to close around the spinal cord, leaving it unprotected. -the b vitamin folate helps prevent spina bifida and other neural tube defects. -spina bifida normal spine vertebra meninges spinal cord spinal fluid spine spine source: from the journal of the american medical association, june 20, 2001, vol. -285, no. -23, p. 3050. reprinted with permission of the american medical association. -folate rda: for women: 400 g (0.4 mg)/day during pregnancy: 600 g (0.6 mg)/day folate supplementation chapter 10 described how folate supplements taken one month before conception and continued throughout the first trimester can help support a healthy pregnancy, prevent neural tube defects, and reduce the severity of those that do occur.8 for this reason, all women of childbearing age who are capa- ble of becoming pregnant should consume 400 micrograms (0.4 milligram) of folate daily. -a woman who has previously had an infant with a neural tube defect may be advised by her physician to take folate supplements in doses ten times larger 4 mil- ligrams daily. -because high doses of folate can mask the symptoms of the pernicious anemia of a vitamin b12 deficiency, quantities of 1 milligram or more require a pre- scription. -most over-the-counter multivitamin supplements contain 400 micrograms of folate; prenatal supplements usually contain at least 800 micrograms. -dietary guidelines for americans 2005 women in their first trimester of pregnancy should consume adequate synthetic folate daily from fortified foods or supplements in addition to naturally occurring folate from a variety of foods. -because half of the pregnancies each year are unplanned and because neural tube defects occur early in development before most women realize they are preg- nant, grain products in the united states are fortified with folate to help ensure an adequate intake. -labels on fortified products may claim that an adequate intake of folate has been shown to reduce the risk of neural tube defects. -fortification has improved folate status in women of childbearing age and lowered the number of neural tube defects that occur each year, as figure 10-10 on p. 340 showed.9 life cycle nutrition: pregnancy and lactation 515 whether folate fortification should be increased further is still the subject of much debate.10 chronic diseases much research suggests that adverse influences at critical times during fetal development set the stage for the infant to develop chronic diseases in adult life.11 poor maternal diet during critical periods may permanently alter body functions such as blood pressure, glucose tolerance, and immune functions that in- fluence disease development.12 for example, maternal diet may alter blood vessel growth and program lipid metabolism and lean body mass development in such a way that the infant will develop risk factors for cardiovascular disease as an adult.13 malnutrition during the critical period of pancreatic cell growth provides an ex- ample of how type 2 diabetes may develop in adulthood.14 the pancreatic cells re- sponsible for producing insulin (the beta cells) normally increase more than 130-fold between 12 weeks gestation and 5 months after birth. -nutrition is a pri- mary determinant of beta cell growth, and infants who have suffered prenatal malnutrition have significantly fewer beta cells than well-nourished infants. -they are also more likely to be low-birthweight infants and low birthweight and prema- ture birth correlate with insulin resistance and type 2 diabetes later in life.15 one hy- pothesis suggests that diabetes may develop from the interaction of inadequate nutrition early in life with abundant nutrition later in life: the small mass of beta cells developed in times of undernutrition during fetal development may be insufficient in times of overnutrition during adulthood when the body needs more insulin.16 hypertension may develop from a similar scenario of inadequate growth during placental and gestational development followed by accelerated growth during early childhood: the small mass of kidney cells developed during malnutrition may be insufficient to handle the excessive demands of later life.17 low-birthweight in- fants who gain weight rapidly as young children are likely to develop hypertension and heart disease as adults.18 fetal programming recent genetic research may help to explain the phenome- non of substances such as nutrients influencing the development of diseases later on in adulthood a process known as fetal programming. -in the case of preg- nancy, the mother s nutrition can permanently change gene expression in the fe- tus.19 some research suggests that fetal programming may influence several succeeding generations.20 in summary maternal nutrition before and during pregnancy affects both the mother s health and the infant s growth. -as the infant develops through its three stages the zygote, embryo, and fetus its organs and tissues grow, each on its own schedule. -times of intense development are critical periods that depend on nutrients to proceed smoothly. -without folate, for example, the neural tube fails to develop completely during the first month of pregnancy, prompting recommendations that all women of childbearing age take folate daily. -because critical periods occur throughout pregnancy, a woman should continuously take good care of her health. -that care should include achieving and maintaining a healthy body weight prior to pregnancy and gaining sufficient weight during pregnancy to support a healthy infant. -maternal weight birthweight is the most reliable indicator of an infant s health. -as a later section of this chapter explains, an underweight infant is more likely to have physical and mental defects, become ill, and die than a normal-weight infant. -in general, higher birthweights present fewer risks for infants. -two characteristics of the mother s fetal programming: the influence of substances during fetal growth on the development of diseases in later life. -516 chapter 15 bmi was introduced in chapter 8. underweight = bmi (cid:2)18.5 normal weight = bmi 18.5 to 24.9 overweight = bmi 25 to 29.9 obesity = bmi 30 the term macrosomia (mak-roh-so-me- ah) describes high-birthweight infants (roughly 9 lb, or 4000 g, or more); macro- somia results from prepregnancy obesity, excessive weight gain during pregnancy, or uncontrolled diabetes. -macro = large soma = body preterm (infant): an infant born prior to the 38th week of pregnancy; also called a premature infant. -a term infant is born between the 38th and 42nd week of pregnancy. -post term (infant): an infant born after the 42nd week of pregnancy. -cesarean section: a surgically assisted birth involving removal of the fetus by an incision into the uterus, usually by way of the abdominal wall. -weight influence an infant s birthweight: her weight prior to conception and her weight gain during pregnancy. -weight prior to conception a woman s weight prior to conception influences fetal growth. -even with the same weight gain during pregnancy, underweight women tend to have smaller babies than heavier women. -underweight an underweight woman has a high risk of having a low- birthweight infant, especially if she is malnourished or unable to gain sufficient weight during pregnancy. -in addition, the rates of preterm births and infant deaths are higher for underweight women. -an underweight woman improves her chances of having a healthy infant by gaining sufficient weight prior to conception or by gaining extra pounds during pregnancy. -to gain weight and ensure nutrient adequacy, an underweight woman can follow the dietary recommendations for pregnant women (described on pp. -520 523). -overweight and obesity an estimated one-third of all pregnant women in the united states are obese, which can create problems related to pregnancy and child- birth.21 obese women have an especially high risk of medical complications such as hypertension, gestational diabetes, and postpartum infections. -compared with other women, obese women are also more likely to have other complications of la- bor and delivery.22 overweight women have the lowest rate of low-birthweight infants. -in fact, in- fants of overweight women are more likely to be born post term and to weigh more than 9 pounds. -large newborns increase the likelihood of a difficult labor and delivery, birth trauma, and cesarean section. -consequently, these infants have a greater risk of poor health and death than infants of normal weight. -of greater concern than infant birthweight is the poor development of infants born to obese mothers. -obesity may double the risk for neural tube defects. -folate s role has been examined, but a more likely explanation seems to be poor glycemic control.23 in addition, both overweight and obese women have a greater risk of giv- ing birth to infants with heart defects and other abnormalities.24 weight-loss dieting during pregnancy is never advisable. -overweight women should try to achieve a healthy body weight before becoming pregnant, avoid ex- cessive weight gain during pregnancy, and postpone weight loss until after child- birth. -weight loss is best achieved by eating moderate amounts of nutrient-dense foods and exercising to lose body fat. -weight gain during pregnancy all pregnant women must gain weight fetal growth and maternal health depend on it. -maternal weight gain during pregnancy correlates closely with infant birthweight, which is a strong predictor of the health and subsequent development of the infant. -dietary guidelines for americans 2005 pregnant women should ensure appropriate weight gain as specified by a healthcare provider. -recommended weight gains table 15-1 presents recommended weight gains for various prepregnancy weights. -the recommended gain for a woman who begins pregnancy at a healthy weight and is carrying a single fetus is 25 to 35 pounds. -an underweight woman needs to gain between 28 and 40 pounds; and an overweight life cycle nutrition: pregnancy and lactation 517 table 15-1 recommended weight gains based on prepregnancy weight prepregnancy weight recommended weight gain underweight (bmi (cid:2)18.5) 28 to 40 lb (12.5 to 18.0 kg) healthy weight (bmi 18.5 to 24.9) 25 to 35 lb (11.5 to 16.0 kg) overweight (bmi 25.0 to 29.9) 15 to 25 lb (7.0 to 11.5 kg) obese (bmi 30) 15 lb minimum (6.8 kg minimum) note: these classifications for bmi are slightly different from those developed in 1990 by the committee on nutritional status during pregnancy and lactation for the publication nutrition during pregnancy (washington, d.c.: national academy press). -that committee acknowledged that because such classifications had not been validated by research on pregnancy outcome, any cut off points will be arbitrary for women of reproductive age. -for these reasons, it seems appropriate to use the values developed for adults in 1998 by the national institutes of health (see chapter 8). -woman, between 15 and 25 pounds. -some women should strive for gains at the up- per end of the target range, notably, adolescents who are still growing themselves and black women whose infants tend to be smaller than white infants even with the same maternal weight gain. -short women (5 feet 2 inches and under) should strive for gains at the lower end of the target range. -women who are carrying twins should aim for a weight gain of 35 to 45 pounds.25 if a woman gains more than is recom- mended early in pregnancy, she should not restrict her energy intake later in order to lose weight. -a large weight gain over a short time, however, indicates excessive fluid retention and may be the first sign of the serious medical complication preeclampsia, which is discussed later. -weight-gain patterns for the normal-weight woman, weight gain ideally fol- lows a pattern of 31/2 pounds during the first trimester and 1 pound per week there- after. -health care professionals monitor weight gain using a prenatal weight-gain grid (see figure 15-7). -components of weight gain women often express concern about the weight gain that accompanies a healthy pregnancy. -they may find comfort by remember- ing that most of the gain supports the growth and development of the placenta, uterus, blood, and breasts, the increase in blood supply and fluid volume, as well as i s b r o c / s t o h s g u m fetal growth and maternal health depend on a sufficient weight gain during pregnancy. -figure 15-7 recommended prenatal weight gain based on prepregnancy weight i d e n a g s d n u o p 44 40 36 32 28 24 20 16 12 8 4 0 4 8 12 16 20 24 28 32 36 40 i d e n a g s d n u o p 44 40 36 32 28 24 20 16 12 8 4 0 4 8 12 16 20 24 28 32 36 40 i d e n a g s d n u o p 44 40 36 32 28 24 20 16 12 8 4 0 4 8 12 16 20 24 28 32 36 40 weeks of gestation weeks of gestation weeks of gestation normal-weight women should gain about 31/2 pounds in the first trimester and just under 1 pound/week thereafter, achieving a total gain of 25 to 35 pounds by term. -underweight women should gain about 5 pounds in the first trimester and just over 1 pound/week thereafter, achieving a total gain of 28 to 40 pounds by term. -overweight women should gain about 2 pounds in the first trimester and 2/3 pound/week thereafter, achieving a total gain of 15 to 25 pounds. -518 chapter 15 figure 15-8 components of weight gain during pregnancy increase in breast size increase in mother's fluid volume placenta increase in blood supply to the placenta amniotic fluid infant at birth increase in size of uterus and supporting muscles mother's necessary fat stores weight gain (lb) 2 4 1 1/2 4 2 7 1/2 2 7 30 st 1 trimester nd 2 trimester rd 3 trimester an optimally healthy 71/2-pound infant. -a small amount goes into maternal fat stores, and even that fat is there for a special purpose to provide energy for labor and lactation. -figure 15-8 shows the components of a typical 30-pound weight gain. -weight loss after pregnancy the pregnant woman loses some weight at deliv- ery. -in the following weeks, she loses more as her blood volume returns to normal and she sheds accumulated fluids. -the typical woman does not, however, return to her prepregnancy weight. -in general, the more weight a woman gains beyond the needs of pregnancy, the more she retains. -even with an average weight gain during pregnancy, most women tend to retain a couple of pounds with each pregnancy. -when those couple of pounds become 7 or more and bmi increases by a unit or more, complications such as diabetes and hypertension in future pregnancies as well as chronic diseases in later life can increase even for women who are not over- weight.26 exercise during pregnancy an active, physically fit woman experiencing a normal pregnancy can continue to exercise throughout pregnancy, adjusting the duration and intensity of activity as the pregnancy progresses. -staying active can improve fitness, prevent or manage gestational diabetes, facilitate labor, and reduce stress. -women who exercise during pregnancy report fewer discomforts throughout their pregnancies. -regular exercise develops the strength and endurance a woman needs to carry the extra weight through pregnancy and to labor through an intense delivery. -it also maintains the habits that help a woman lose excess weight and get back into shape after the birth. -a pregnant woman should participate in low-impact activities and avoid sports in which she might fall or be hit by other people or objects. -for example, playing singles tennis with one person on each side of the net is safer than a fast- moving game of racquetball in which the two competitors can collide. -swimming and water aerobics are particularly beneficial because they allow the body to re- main cool and move freely with the water s support, thus reducing back pain. -fig- ure 15-9 provides some guidelines for exercise during pregnancy.27 several of the guidelines are aimed at preventing excessively high internal body temperature and figure 15-9 exercise guidelines during pregnancy life cycle nutrition: pregnancy and lactation 519 do do begin to exercise gradually. -do exercise regularly (most, if not all, days of the week). -do warm up with 5 to 10 minutes of light activity. -do 30 minutes or more of moderate physical activity; 20 to 60 minutes of more intense activity on 3 to 5 days a week will provide greater benefits. -do cool down with 5 to 10 minutes of slow activity and gentle stretching. -do drink water before, after, and during exercise. -do eat enough to support the needs of pregnancy plus exercise. -s e g a m i y t t e g / k n a b e g a m i / l e k n a r f y c a r t do rest adequately. -pregnant women can enjoy the benefits of exercise. -don t don t exercise vigorously after long periods of inactivity. -don t exercise in hot, humid weather. -don t exercise when sick with fever. -don t exercise while lying on your back after the first trimester of pregnancy or stand motionless for prolonged periods. -don t exercise if you experience any pain, discomfort, or fatigue. -don t participate in activities that may harm the abdomen or involve jerky, bouncy movements. -dehydration, both of which can harm fetal development. -to this end, pregnant women should also stay out of saunas, steam rooms, and hot tubs or hot whirlpool baths. -dietary guidelines for americans 2005 healthy pregnant women should incorporate 30 minutes or more of mod- erately intense physical activity on most, if not all, days of the week and avoid activities with a high risk of falling or abdominal trauma. -in summary a healthy pregnancy depends on a sufficient weight gain. -women who begin their pregnancies at a healthy weight need to gain about 30 pounds, which covers the growth and development of the placenta, uterus, blood, breasts, and infant. -by remaining active throughout pregnancy, a woman can develop the strength she needs to carry the extra weight and maintain habits that will help her lose it after the birth. -nutrition during pregnancy a woman s body changes dramatically during pregnancy. -her uterus and its sup- porting muscles increase in size and strength; her blood volume increases by half to carry the additional nutrients and other materials; her joints become more flexible in preparation for childbirth; her feet swell in response to high concentrations of the hormone estrogen, which promotes water retention and helps to ready the uterus for delivery; and her breasts enlarge in preparation for lactation. -the hormones that mediate all these changes may influence her mood. -she can best prepare to handle these changes given a nutritious diet, regular physical activity, plenty of rest, and caring companions. -this section highlights the role of nutrition. -i s b r o c / z e m o g k c i r a pregnant woman s food choices support both her health and her infant s growth and development. -520 chapter 15 the dietary reference intakes (dri) table on the inside front cover provides separate listings for women during pregnancy and lactation, reflecting their heightened nutri- ent needs. -chapters 10 13 presented details on the vitamins and minerals. -energy requirement during pregnancy: 2nd trimester: + 340 kcal/day 3rd trimester: + 450 kcal/day protein rda during pregnancy: + 25 g/day folate rda during pregnancy: 600 g/day vitamin b12 rda during pregnancy: 2.6 g/day energy and nutrient needs during pregnancy from conception to birth, all parts of the infant bones, muscles, organs, blood cells, skin, and other tissues are made from nutrients in the foods the mother eats. -for most women, nutrient needs during pregnancy and lactation are higher than at any other time (see figure 15-10). -to meet the high nutrient demands of pregnancy, a woman will need to make careful food choices, but her body will also help by max- imizing absorption and minimizing losses. -energy the enhanced work of pregnancy raises the basal metabolic rate dramat- ically and demands extra energy.28 energy needs of pregnant women are greater than those of nonpregnant women an additional 340 kcalories per day during the second trimester and an extra 450 kcalories per day during the third. -a woman can easily get these added kcalories with nutrient dense selections from the five food groups. -see table 2-3 (p. 41) for suggested dietary patterns for several kcalorie levels and figure 15-11 (p. 522) for a sample menu for pregnant and lac- tating women. -for a 2000-kcalorie daily intake, these added kcalories represent about 15 to 20 percent more food energy than before pregnancy. -the increase in nutrient needs is often greater than this, so nutrient-dense foods should be chosen to supply the ex- tra kcalories: foods such as whole-grain breads and cereals, legumes, dark green vegetables, citrus fruits, low-fat milk and milk products, and lean meats, fish, poul- try, and eggs. -ample carbohydrate (ideally, 175 grams or more per day and cer- tainly no less than 135 grams) is necessary to fuel the fetal brain. -sufficient carbohydrate ensures that the protein needed for growth will not be broken down and used to make glucose. -protein the protein rda for pregnancy is an additional 25 grams per day higher than for nonpregnant women. -pregnant women can easily meet their protein needs by selecting meats, milk products, and protein-containing plant foods such as legumes, whole grains, nuts, and seeds. -because use of high-protein supplements during pregnancy may be harmful to the infant s development, it is discouraged. -essential fatty acids the high nutrient requirements of pregnancy leave little room in the diet for excess fat, but the essential long-chain polyunsaturated fatty acids are particularly important to the growth and development of the fetus. -the brain is largely made of lipid material, and it depends heavily on the long-chain omega-3 and omega-6 fatty acids for its growth, function, and structure.29 (see table 5-2 on p. 159 for a list of good food sources of the omega fatty acids.) -nutrients for blood production and cell growth new cells are laid down at a tremendous pace as the fetus grows and develops. -at the same time, the mother s red blood cell mass expands. -all nutrients are important in these processes, but for folate, vitamin b12, iron, and zinc, the needs are especially great due to their key roles in the synthesis of dna and new cells. -the requirement for folate increases dramatically during pregnancy. -it is best to obtain sufficient folate from a combination of supplements, fortified foods, and a diet that includes fruits, juices, green vegetables, and whole grains.30 the how to feature in chapter 10 on p. 339 described how folate from each of these sources contributes to a day s intake. -the pregnant woman also has a slightly greater need for the b vitamin that ac- tivates the folate enzyme vitamin b12. -generally, even modest amounts of meat, fish, eggs, or milk products together with body stores easily meet the need for vitamin b12. -vegans who exclude all foods of animal origin, however, need daily supplements of vitamin b12 or vitamin b12-fortified foods to prevent the neurologi- cal complications of a deficiency. -life cycle nutrition: pregnancy and lactation 521 figure 15-10 comparison of nutrient recommendations for nonpregnant, pregnant, and lactating women for actual values, turn to the table on the inside front cover. -0 50 100 150 200 250 percent energya protein carbohydrate fiber linoleic acid linolenic acid vitamin a vitamin d vitamin e vitamin k thiamin riboflavin niacin biotin pantothenic acid vitamin b6 folate vitamin b12 choline vitamin c calcium phosphorus magnesium iron zinc iodine selenium fluoride key: nonpregnant (set at 100% for a woman 24 years old) pregnant lactating the increased need for iron in pregnancy cannot be met by diet or by existing stores. -therefore, iron supplements are recommended during the 2nd and 3rd trimesters. -aenergy allowance during pregnancy is for 2nd trimester; energy allowance during the 3rd trimester is slightly higher; no additional allowance is provided during the 1st trimester. -energy allowance during lactation is for the first 6 months; energy allowance during the second 6 months is slightly higher. -522 chapter 15 iron rda during pregnancy: 27 mg/day zinc rda during pregnancy: 12 mg/day ((cid:3)18 yr) 11 mg/day (19 50 yr) the ai for vitamin d does not increase dur- ing pregnancy. -figure 15-11 daily food choices for pregnant and lactating women breakfast 1 whole-wheat english muffin 2 tbs peanut butter 1 c low-fat vanilla yogurt 1/2 c fresh strawberries 1 c orange juice midmorning snack 1/2 c cranberry juice 1 oz pretzels lunch sandwich (tuna salad on whole-wheat bread) 1/2 carrot (sticks) 1 c low-fat milk dinner chicken cacciatore 3 oz chicken 1/2 c stewed tomatoes 1 c rice 1/2 c summer squash 11/2 c salad (spinach, mushrooms, carrots) 1 tbs salad dressing 1 slice italian bread 2 tsp soft margarine 1 c low-fat milk note: this sample meal plan provides about 2500 kcalories (55% from carbohydrate, 20% from protein, and 25% from fat) and meets most of the vitamin and mineral needs of pregnant and lactating women. -pregnant women need iron to support their enlarged blood volume and to provide for placental and fetal needs.31 the developing fetus draws on maternal iron stores to create sufficient stores of its own to last through the first four to six months after birth. -even women with inadequate iron stores transfer significant amounts of iron to the fetus, suggesting that the iron needs of the fetus have prior- ity over those of the mother.32 in addition, blood losses are inevitable at birth, espe- cially during a cesarean section, and can further drain the mother s supply. -* during pregnancy, the body makes several adaptations to help meet the excep- tionally high need for iron. -menstruation, the major route of iron loss in women, ceases, and iron absorption improves thanks to an increase in blood transferrin, the body s iron-absorbing and iron-carrying protein. -without sufficient intake, though, iron stores would quickly dwindle. -few women enter pregnancy with adequate iron stores, so a daily iron supplement is recommended during the second and third trimesters for all pregnant women. -for this reason, most prenatal supplements provide 30 to 60 milligrams of iron a day. -to enhance iron absorption, the supplement should be taken between meals or at bed- time and with liquids other than milk, coffee, or tea, which inhibit iron absorption. -drinking orange juice does not enhance iron absorption from supplements as it does from foods; vitamin c enhances iron absorption by converting iron from ferric to fer- rous, but supplemental iron is already in the ferrous form. -vitamin c is helpful, how- ever, in preventing the premature rupture of amniotic membranes.33 zinc is required for dna and rna synthesis and thus for protein synthesis and cell development. -typical zinc intakes for pregnant women are lower than recom- mendations, but fortunately, zinc absorption increases when zinc intakes are low.34 routine supplementation is not advised.35 women taking iron supplements (more than 30 milligrams per day), however, may need zinc supplementation because large doses of iron can interfere with the body s absorption and use of zinc. -nutrients for bone development vitamin d and the bone-building minerals calcium, phosphorus, magnesium, and fluoride are in great demand during preg- nancy. -insufficient intakes may produce abnormal fetal bones and teeth. -vitamin d plays a vital role in calcium absorption and utilization. -conse- quently, severe maternal vitamin d deficiency interferes with normal calcium me- tabolism, resulting in rickets in the infant and osteomalacia in the mother.36 regular exposure to sunlight and consumption of vitamin d fortified milk are usu- ally sufficient to provide the recommended amount of vitamin d during preg- * on average, almost twice as much blood is lost during a cesarean delivery as during the average vagi- nal delivery of a single fetus. -life cycle nutrition: pregnancy and lactation 523 the ai for calcium does not increase during pregnancy. -the usda food guide suggests consuming 3 cups per day of fat-free or low-fat milk or the equivalent in milk products. -nancy, although some researchers question whether current recommendations are adequate.37 routine supplementation is not recommended because of the toxicity risk. -vegans who avoid milk, eggs, and fish may receive enough vitamin d from regular exposure to sunlight and from fortified soy milk. -calcium absorption and retention increases dramatically in pregnancy, helping the mother to meet the calcium needs of pregnancy.38 during the last trimester, as the fetal bones begin to calcify, over 300 milligrams a day are transferred to the fetus. -recommendations to ensure an adequate calcium intake during pregnancy help to conserve maternal bone while supplying fetal needs.39 calcium intakes for pregnant women typically fall below recommendations. -because bones are still actively depositing minerals until about age 30, adequate calcium is especially important for young women. -pregnant women under age 25 who receive less than 600 milligrams of dietary calcium daily need to increase their intake of milk, cheese, yogurt, and other calcium-rich foods. -alternatively, and less preferably, they may need a daily supplement of 600 milligrams of calcium. -other nutrients the nutrients mentioned here are those most intensely involved in blood production, cell growth, and bone growth. -of course, other nutrients are also needed during pregnancy to support the growth and health of both fetus and mother. -even with adequate nutrition, repeated pregnancies, less than a year apart, deplete nutrient reserves. -when this happens, fetal growth may be compromised, and mater- nal health may decline. -the optimal interval between pregnancies is 18 to 23 months. -nutrient supplements pregnant women who make wise food choices can meet most of their nutrient needs, with the possible exception of iron. -even so, physicians routinely recommend daily multivitamin-mineral supplements for pregnant women. -prenatal supplements typically contain greater amounts of folate, iron, and calcium than regu- lar vitamin-mineral supplements. -these supplements are particularly beneficial for women who do not eat adequately and for those in high-risk groups: women carrying multiple fetuses, cigarette smokers, and alcohol and drug abusers. -the use of prenatal supplements may help reduce the risks of preterm delivery, low infant birthweights, and birth defects. -supplement use prior to conception also seems to reduce the risk of preterm births.40 figure 15-12 presents a label from a standard prenatal supplement. -figure 15-12 example of a prenatal supplement supplement facts serving size 1 tablet amount per tablet % daily value for pregnant/ lactating women vitamin a 4000 iu vitamin c 100 mg vitamin d 400 iu vitamin e 11 iu thiamin 1.84 mg riboflavin 1.7 mg niacin 18 mg vitamin b6 2.6 mg folate 800 mcg vitamin b12 4 mcg calcium 200 mg iron 27 mg zinc 25 mg 50% 167% 100% 37% 108% 85% 90% 104% 100% 50% 15% 150% 167% ingredients: calcium carbonate, microcrystalline cellulose, dicalcium phosphate, ascorbic acid, ferrous fumarate, zinc oxide, acacia, sucrose ester, niacinamide, modified cellulose gum, di-alpha tocopheryl acetate, hydroxypropyl methylcellulose, hydroxypropyl cellulose, artificial colors (fd&c blue no. -1 lake, fd&c red no. -40 lake, fd&c yellow no. -6 lake, titanium dioxide), polyethylene glycol, starch, pyridoxine hydrochloride, vitamin a acetate, riboflavin, thiamin mononitrate, folic acid, beta carotene, cholecalciferol, maltodextrin, gluten, cyanocobalamin, sodium bisulfite. -524 chapter 15 vegetarian diets during pregnancy and lactation in general, a vegetarian diet can support a healthy pregnancy and successful lacta- tion if it provides adequate energy; includes milk and milk products; and contains a wide variety of legumes, cereals, fruits, and vegetables.41 many vegetarian women are well nourished, with nutrient intakes from diet alone exceeding the rda for all vitamins and minerals except iron, which is low for most women. -in contrast, vegan women who restrict themselves to an exclusively plant-based diet generally have low food energy intakes and are thin. -for pregnant women, this can be a problem. -women with low prepregnancy weights and small weight gains during pregnancy jeopardize a healthy pregnancy. -vegan diets may require supplementation with vitamin b12, calcium, and vita- min d, or the addition of foods fortified with these nutrients. -infants of vegan par- ents may suffer spinal cord damage and develop severe psychomotor retardation due to a lack of vitamin b12 in the mother s diet during pregnancy. -breastfed infants of vegan mothers have been reported to develop vitamin b12 deficiency and severe movement disorders. -giving the infants vitamin b12 supplements corrects the blood and neurological symptoms of deficiency, as well as the structural abnormalities, but cognitive and language development delays may persist. -a vegan mother needs a regular source of vitamin b12-fortified foods or a supplement that provides 2.6 micrograms daily. -a pregnant woman who cannot meet her calcium needs through diet alone may need 600 milligrams of supplemental calcium daily, taken with meals. -preg- nant women who do not receive sufficient dietary vitamin d or enough exposure to sunlight may need a supplement that provides 10 micrograms daily. -common nutrition-related concerns of pregnancy nausea, constipation, heartburn, and food sensitivities are common nutrition- related concerns during pregnancy. -a few simple strategies can help alleviate mater- nal discomforts (see table 15-2). -nausea not all women have queasy stomachs in the early months of pregnancy, but many do. -the nausea of morning sickness may actually occur anytime and ranges from mild queasiness to debilitating nausea and vomiting. -severe and con- tinued vomiting may require hospitalization if it results in acidosis, dehydration, or excessive weight loss. -the hormonal changes of early pregnancy seem to be respon- sible for a woman s sensitivities to the appearance, texture, or smell of foods. -tradi- tional strategies for quelling nausea are listed in table 15-2, but some women table 15-2 strategies to alleviate maternal discomforts to alleviate the nausea of pregnancy to prevent or alleviate constipation to prevent or relieve heartburn on waking, arise slowly. -eat dry toast or crackers. -chew gum or suck hard candies. -eat small, frequent meals. -avoid foods with offensive odors. -when nauseated, drink carbonated beverages instead of citrus juice, water, milk, coffee, or tea. -eat foods high in fiber (fruits, vegetables, and whole-grain cereals). -exercise regularly. -drink at least eight glasses of liquids a day. -respond promptly to the urge to defecate. -use laxatives only as prescribed by a physi- cian; do not use mineral oil, because it inter- feres with absorption of fat-soluble vitamins. -relax and eat slowly. -chew food thoroughly. -eat small, frequent meals. -drink liquids between meals. -avoid spicy or greasy foods. -sit up while eating; elevate the head while sleeping. -wait an hour after eating before lying down. -wait two hours after eating before exercising. -life cycle nutrition: pregnancy and lactation 525 benefit most from resting when nauseous and simply eating the foods they want when they feel like eating. -they may also find comfort in a cleaner, quieter, and more temperate environment. -constipation and hemorrhoids as the hormones of pregnancy alter muscle tone and the growing fetus crowds intestinal organs, an expectant mother may ex- perience constipation. -she may also develop hemorrhoids (swollen veins of the rec- tum). -hemorrhoids can be painful, and straining during bowel movements may cause bleeding. -she can gain relief by following the strategies listed in table 15-2. heartburn heartburn is another common complaint during pregnancy. -the hor- mones of pregnancy relax the digestive muscles, and the growing fetus puts increas- ing pressure on the mother s stomach. -this combination allows stomach acid to back up into the lower esophagus, creating a burning sensation near the heart. -tips to help relieve heartburn are included in table 15-2. food cravings and aversions some women develop cravings for, or aversions to, particular foods and beverages during pregnancy. -food cravings and food aversions are fairly common, but they do not seem to reflect real physiological needs. -in other words, a woman who craves pickles does not necessarily need salt. -similarly, cravings for ice cream are common in pregnancy but do not signify a cal- cium deficiency. -cravings and aversions that arise during pregnancy are most likely due to hormone-induced changes in sensitivity to taste and smell. -nonfood cravings some pregnant women develop cravings for nonfood items such as freezer frost, laundry starch, clay, soil, or ice a practice known as pica. -pica is a cultural phenomenon that reflects a society s folklore; it is especially common among african american women.42 pica is often associated with iron-deficiency anemia, but whether iron deficiency leads to pica or pica leads to iron deficiency is unclear. -eating clay or soil may interfere with iron absorption and displace iron-rich foods from the diet. -in summary energy and nutrient needs are high during pregnancy. -a balanced diet that includes an extra serving from each of the five food groups can usually meet these needs, with the possible exception of iron and folate (supplements are recommended). -the nausea, constipation, and heartburn that sometimes ac- company pregnancy can usually be alleviated with a few simple strategies. -food cravings do not typically reflect physiological needs. -high-risk pregnancies some pregnancies jeopardize the life and health of the mother and infant. -table 15- 3 (p. 526) identifies several characteristics of a high-risk pregnancy. -a woman with none of these risk factors is said to have a low-risk pregnancy. -the more fac- tors that apply, the higher the risk. -all pregnant women, especially those in high- risk categories, need prenatal care, including dietary advice. -the infant s birthweight a high-risk pregnancy is likely to produce an infant with low birthweight. -low- birthweight infants, defined as infants who weigh 51/2 pounds or less, are classi- fied according to their gestational age. -preterm infants are born before they are fully developed; they are often underweight and have trouble breathing because their lungs are immature. -preterm infants may be small, but if their size and reminder: pica is the general term for eat- ing nonfood items. -the specific craving for nonfood items that come from the earth, such as clay or dirt, is known as geophagia. -nutrition advice in prenatal care: eat well-balanced meals. -gain enough weight to support fetal growth. -take prenatal supplements as prescribed. -stop drinking alcohol. -food cravings: strong desires to eat particular foods. -food aversions: strong desires to avoid particular foods. -high-risk pregnancy: a pregnancy characterized by indicators that make it likely the birth will be surrounded by problems such as premature delivery, difficult birth, retarded growth, birth defects, and early infant death. -low-risk pregnancy: a pregnancy characterized by indicators that make a normal outcome likely. -low birthweight (lbw): a birthweight of 5 1/2 lb (2500 g) or less; indicates probable poor health in the newborn and poor nutrition status in the mother during pregnancy, before pregnancy, or both. -normal birthweight for a full-term baby is 61/2 to 83/4 lb (about 3000 to 4000 g). -526 chapter 15 low-birthweight babies need special care and nourishment. -the weight of some preterm infants is appropriate for gestational age (aga); others are small for gestational age (sga), often reflecting malnutrition. -reminder: amenorrhea is the temporary or permanent absence of menstrual periods. -amenorrhea is normal before puberty, after menopause, during pregnancy, and during lactation; otherwise it is abnormal. -table 15-3 high-risk pregnancy factors factor maternal weight condition that raises risk prior to pregnancy prepregnancy bmi either (cid:2)18.5 or (cid:4)25 during pregnancy insufficient or excessive pregnancy weight gain maternal nutrition nutrient deficiencies or toxicities; eating disorders socioeconomic status lifestyle habits age previous pregnancies number interval outcomes multiple births birthweight maternal health s e g a m i y t t e g / e n i v y r r e t poverty, lack of family support, low level of education, limited food available smoking, alcohol or other drug use teens, especially 15 years or younger; women 35 years or older many previous pregnancies (3 or more to mothers under age 20; 4 or more to mothers age 20 or older) short or long intervals between pregnancies ((cid:2)18 months or (cid:4)59 months) previous history of problems twins or triplets low- or high-birthweight infants high blood pressure development of pregnancy-related hypertension diabetes chronic diseases development of gestational diabetes diabetes; heart, respiratory, and kidney disease; certain genetic disorders; special diets and medications weight are appropriate for their age, they can catch up in growth given adequate nutrition support. -in contrast, small-for-gestational-age infants have suffered growth failure in the uterus and do not catch up as well. -for the most part, survival improves with increased gestational age and birthweight. -low-birthweight infants are more likely to experience complications during de- livery than normal-weight babies. -they also have a statistically greater chance of having physical and mental birth defects, contracting diseases, and dying early in life. -of infants who die before their first birthdays, about two-thirds were low- birthweight newborns. -very-low-birthweight infants (31/2 pounds or less) struggle not only for their immediate physical health and survival, but for their future cog- nitive development and abilities as well. -a strong relationship is evident between socioeconomic disadvantage and low birthweight. -low socioeconomic status impairs fetal development by causing stress and by limiting access to medical care and to nutritious foods. -low socioeconomic status often accompanies teen pregnancies, smoking, and alcohol and drug abuse all predictors of low birthweight. -malnutrition and pregnancy good nutrition clearly supports a pregnancy. -in contrast, malnutrition interferes with the ability to conceive, the likelihood of implantation, and the subsequent de- velopment of a fetus should conception and implantation occur.43 malnutrition and fertility the nutrition habits and lifestyle choices people make can influence the course of a pregnancy they are not even planning at the time. -severe malnutrition and food deprivation can reduce fertility because women may develop amenorrhea, and men may be unable to produce viable sperm. -fur- thermore, both men and women lose sexual interest during times of starvation. -starvation arises predictably during famines, wars, and droughts, but it can also oc- cur amidst peace and plenty. -many young women who diet excessively are starving and suffering from malnutrition (see highlight 8). -life cycle nutrition: pregnancy and lactation 527 malnutrition and early pregnancy if a malnourished woman does become pregnant, she faces the challenge of supporting both the growth of a baby and her own health with inadequate nutrient stores. -malnutrition prior to and around conception prevents the placenta from developing fully. -a poorly developed pla- centa cannot deliver optimum nourishment to the fetus, and the infant will be born small and possibly with physical and cognitive abnormalities. -if this small infant is a female, she may develop poorly and have an elevated risk of develop- ing a chronic condition that could impair her ability to give birth to a healthy in- fant. -thus a woman s malnutrition can adversely affect not only her children but her grandchildren. -malnutrition and fetal development without adequate nutrition during pregnancy, fetal growth and infant health are compromised. -in general, conse- quences of malnutrition during pregnancy include fetal growth retardation, con- genital malformations (birth defects), spontaneous abortion and stillbirth, preterm birth, and low infant birthweight. -preterm birth and low infant birthweight, in turn, predict the risk of stillbirth in a subsequent pregnancy.44 malnutrition, coupled with low birthweight, is a factor in more than half of all deaths of children under four years of age worldwide. -food assistance programs women in high-risk pregnancies can find assistance from the wic program a high-quality, cost-effective health care and nutrition services program for women, infants, and children in the united states. -formally known as the special supple- mental nutrition program for women, infants, and children, wic provides nutri- tion education and nutritious foods to infants, children up to age five, and pregnant and breastfeeding women who qualify financially and have a high risk of medical or nutritional problems. -the program is both remedial and preven- tive: services include health care referrals, nutrition education, and food packages or vouchers for specific foods. -these foods supply nutrients known to be lacking in the diets of the target population most notably, protein, calcium, iron, vitamin a, and vitamin c. wic-sponsored foods include tuna fish, carrots, eggs, milk, iron-fortified cereal, vitamin c-rich juice, cheese, legumes, peanut butter, and in- fant formula. -more than 7 million people most of them young children receive wic bene- fits each month. -prenatal wic participation can effectively reduce infant mortal- ity, low birthweight, and maternal and newborn medical costs. -in 2003, congress appropriated over $4.5 billion for wic. -for every dollar spent on wic, an esti- mated three dollars in medical costs are saved in the first two months after birth. -maternal health medical disorders can threaten the life and health of both mother and fetus. -if diag- nosed and treated early, many diseases can be managed to ensure a healthy out- come another strong argument for early prenatal care. -furthermore, the changes in pregnancy can reveal disease risks, making screening important and early inter- vention possible.45 preexisting diabetes whether diabetes presents risks depends on how well it is controlled before and during pregnancy. -without proper management of maternal diabetes, women face high infertility rates, and those who do conceive may experi- ence episodes of severe hypoglycemia or hyperglycemia, spontaneous abortions, and pregnancy-related hypertension. -infants may be large, suffer physical and mental abnormalities, and experience other complications such as severe hypo- glycemia or respiratory distress, both of which can be fatal. -ideally, a woman with diabetes will receive the prenatal care needed to achieve glucose control before con- ception and continued glucose control throughout pregnancy. -wic participants: 1/3 of all pregnant women 1/2 of all infants 1/4 of all children ages 1 4 yr 528 chapter 15 risk factors for gestational diabetes: age 25 or older bmi (cid:4)25 or excessive weight gain complications in previous pregnancies, including gestational diabetes or high- birthweight infant prediabetes or symptoms of diabetes family history of diabetes hispanic, black, native american, south or east asian, pacific islander, or indige- nous australian the hypertensive diseases of pregnancy are sometimes called toxemia. -the normal edema of pregnancy responds to gravity; fluid pools in the ankles. -the edema of preeclampsia is a generalized edema. -the differences between these two types of edema help with the diagnosis of preeclampsia. -warning signs of preeclampsia: hypertension protein in the urine upper abdominal pain severe and constant headaches swelling, especially of the face dizziness blurred vision sudden weight gain (1 lb/day) fetal growth retardation gestational diabetes: abnormal glucose tolerance during pregnancy. -transient hypertension of pregnancy: high blood pressure that develops in the second half of pregnancy and resolves after childbirth, usually without affecting the outcome of the pregnancy. -preeclampsia (pre-ee-klamp-see-ah): a condition characterized by hypertension, fluid retention, and protein in the urine; formerly known as pregnancy-induced hypertension. -* eclampsia (eh-klamp-see-ah): a severe stage of preeclampsia characterized by convulsions. -* the working group on high blood pressure in pregnancy, convened by the national high blood pressure education program of the national heart, lung, and blood institute, suggested abandoning the term pregnancy-induced hypertension because it failed to differentiate between the mild, transient hypertension of pregnancy and the life-threaten- ing hypertension of preeclampsia. -gestational diabetes for every 14 women entering pregnancy without diabetes, one will develop a condition known as gestational diabetes during pregnancy. -ges- tational diabetes usually develops during the second half of pregnancy, with subse- quent return to normal after childbirth. -some women with gestational diabetes, however, develop diabetes (usually type 2) after pregnancy, especially if they are over- weight. -for this reason, health care professionals strongly advise against excessive weight gain during pregnancy. -the most common consequences of gestational diabetes are complications dur- ing labor and delivery and a high infant birthweight.46 birth defects associated with gestational diabetes include heart damage, limb deformities, and neural tube defects. -to ensure that the problems of gestational diabetes are dealt with promptly, physicians screen for the risk factors listed in the margin and test high-risk women for glucose intolerance immediately and average-risk women between 24 and 28 weeks gestation.47 dietary recommendations should meet the needs of preg- nancy and maternal blood glucose goals.48 to maintain normal blood glucose lev- els, carbohydrates should be restricted to 35 to 40 percent of energy intake. -to limit excessive weight gain, obese women should limit energy intake to about 25 kcalo- ries per kilogram body weight. -diet and moderate exercise may control gestational diabetes, but if blood glucose fails to normalize, insulin or other drugs may be re- quired. -importantly, treatment reduces birth complications, infant deaths, and maybe even postpartum depression.49 preexisting hypertension hypertension complicates pregnancy and affects its outcome in different ways, depending on when the hypertension first develops and on how severe it becomes. -in addition to the threats hypertension always carries (such as heart attack and stroke), high blood pressure increases the risks of a low- birthweight infant or the separation of the placenta from the wall of the uterus be- fore the birth, resulting in stillbirth. -ideally, before a woman with hypertension becomes pregnant, her blood pressure is under control. -transient hypertension of pregnancy some women develop hypertension during the second half of pregnancy. -* most often, the rise in blood pressure is mild and does not affect the pregnancy adversely. -blood pressure usually returns to nor- mal during the first few weeks after childbirth. -this transient hypertension of pregnancy differs from the life-threatening hypertensive diseases of pregnancy preeclampsia and eclampsia. -preeclampsia and eclampsia hypertension may signal the onset of preeclampsia, a condition characterized not only by high blood pressure but also by protein in the urine and fluid retention (edema). -the edema of preeclampsia is a whole-body edema, distinct from the localized fluid retention women normally ex- perience late in pregnancy. -the cause of preeclampsia remains unclear, but it usually occurs with first preg- nancies and most often after 20 weeks gestation.50 symptoms typically regress within two days of delivery. -both men and women who were born of pregnancies complicated by preeclampsia are more likely to have a child born of a pregnancy complicated by preeclampsia, suggesting a genetic predisposition. -black women have a much greater risk of preeclampsia than white women. -preeclampsia affects almost all of the mother s organs the circulatory system, liver, kidneys, and brain. -blood flow through the vessels that supply oxygen and nutrients to the placenta diminishes. -for this reason, preeclampsia often retards fe- tal growth. -in some cases, the placenta separates from the uterus, resulting in preterm birth or stillbirth. -preeclampsia can progress rapidly to eclampsia a condition characterized by convulsive seizures and coma. -maternal death during pregnancy and childbirth is * blood pressure of 140/90 millimeters mercury or greater during the second half of pregnancy in a woman who has not previously exhibited hypertension indicates high blood pressure. -so does a rise in systolic blood pressure of 30 millimeters or in diastolic blood pressure of 15 millimeters on at least two occasions more than six hours apart. -by this rule, an apparently normal blood pressure of 120/85 is high for a woman whose normal value is 90/70. -life cycle nutrition: pregnancy and lactation 529 extremely rare in developed countries, but when it does occur, eclampsia is a com- mon cause. -the rate of death for black women with eclampsia is more than four times the rate for white women. -preeclampsia demands prompt medical attention. -treatment focuses on con- trolling blood pressure and preventing convulsions. -if preeclampsia develops early and is severe, induced labor or cesarean section may be necessary, regardless of ges- tational age. -the infant will be preterm, with all of the associated problems, includ- ing poor lung development and special care needs. -several dietary factors have been studied, but none have proved conclusive in preventing preeclampsia. -lim- ited research suggests that exercise may protect against preeclampsia by stimulat- ing placenta growth and vascularity and reducing oxidative stress.51 the mother s age maternal age also influences the course of a pregnancy. -compared with women of the physically ideal childbearing age of 20 to 25, both younger and older women face more complications of pregnancy. -pregnancy in adolescents many adolescents become sexually active before age 19, and approximately 900,000 adolescent girls face pregnancies each year in the united states; slightly more than half of them give birth.52 nourishing a growing fe- tus adds to a teenage girl s nutrition burden, especially if her growth is still incom- plete. -simply being young increases the risks of pregnancy complications independently of important socioeconomic factors. -common complications among adolescent mothers include iron-deficiency anemia (which may reflect poor diet and inadequate prenatal care) and prolonged labor (which reflects the mother s physical immaturity). -on a positive note, mater- nal death is lowest for mothers under age 20. pregnant teenagers have higher rates of stillbirths, preterm births, and low-birth- weight infants than do adult women. -many of these infants suffer physical prob- lems, require intensive care, and die within the first year. -the care of infants born to teenagers costs our society an estimated $1 billion annually. -because teenagers have few financial resources, they cannot pay these costs. -furthermore, their low eco- nomic status contributes significantly to the complications surrounding their preg- nancies. -at a time when prenatal care is most important, it is less accessible. -and the pattern of teenage pregnancies continues from generation to generation, with al- most 40 percent of the daughters born to teenage mothers becoming teenage moth- ers themselves. -clearly, teenage pregnancy is a major public health problem. -to support the needs of both mother and fetus, young teenagers (13 to 16 years old) are encouraged to strive for the highest weight gains recommended for pregnancy. -for a teen who enters pregnancy at a healthy body weight, a weight gain of approxi- mately 35 pounds is recommended; this amount minimizes the risk of delivering a low-birthweight infant. -gaining less weight may limit fetal growth. -pregnant and lac- tating teenagers can use the usda food guide presented in table 2-3 and figure 2-1 (pp. -41 43), making sure to select a high enough kcalorie level to support adequate weight gain. -without the appropriate economic, social, and physical support, a young mother will not be able to care for herself during her pregnancy and for her child after the birth. -to improve her chances for a successful pregnancy and a healthy in- fant, she must seek prenatal care. -wic helps pregnant teenagers obtain adequate food for themselves and their infants. -(wic is introduced on p. -527.) -pregnancy in older women in the last several decades, many women have de- layed childbearing while they pursue education and careers. -as a result, the num- ber of first births to women 35 and older has increased dramatically. -most of these women, even those over age 50, have healthy pregnancies.53 the few complications associated with later childbearing often reflect chronic conditions such as hypertension and diabetes, which can complicate an otherwise healthy pregnancy. -these complications may result in a cesarean section, which is 530 chapter 15 reminder: the word teratogenic describes a factor that causes abnormal fetal develop- ment and birth defects. -the word perinatal refers to the time between the 28th week of gestation and 1 month after birth. -down syndrome: a genetic abnormality that causes mental retardation, short stature, and flattened facial features. -twice as common in women over 35 as among younger women. -for all these rea- sons, maternal death rates are higher in women over 35 than in younger women. -the babies of older mothers face problems of their own including higher rates of preterm births and low birthweight.54 their rates of birth defects are also high. -because 1 out of 50 pregnancies in older women produces an infant with genetic abnormali- ties, obstetricians routinely screen women older than 35. for a 40-year-old mother, the risk of having a child with down syndrome, for example, is about 1 in 100 com- pared with 1 in 300 for a 35-year-old and 1 in 10,000 for a 20-year-old. -in addition, fe- tal death is twice as high for women 35 years and older than for younger women. -why this is so remains a bit of a mystery. -one possibility is that the uterine blood vessels of older women may not fully adapt to the increased demands of pregnancy. -practices incompatible with pregnancy besides malnutrition, a variety of lifestyle factors can have adverse effects on preg- nancy, and some may be teratogenic. -people who are planning to have children can make the choice to practice healthy behaviors. -alcohol one out of ten pregnant women drinks alcohol at some time during her pregnancy; 1 out of 50 drinks frequently.55 alcohol consumption during pregnancy can cause irreversible mental and physical retardation of the fetus fetal alcohol syndrome (fas). -of the leading causes of mental retardation, fas is the only one that is totally preventable. -to that end, the surgeon general urges all pregnant women to refrain from drinking alcohol. -fetal alcohol syndrome is the topic of high- light 15, which includes mention of how alcohol consumption by men may also af- fect fertility and fetal development. -medicinal drugs drugs other than alcohol can also cause complications during pregnancy, problems in labor, and serious birth defects. -for these reasons, pregnant women should not take any medicines without consulting their physicians, who must weigh the benefits against the risks. -herbal supplements similarly, pregnant women should seek a physician s ad- vice before using herbal supplements. -women sometimes seek herbal preparations during their pregnancies to quell nausea, induce labor, aid digestion, promote wa- ter loss, support restful sleep, and fight depression. -as highlight 18 explains, some herbs may be safe, but many others are definitely harmful. -illicit drugs the recommendation to avoid drugs during pregnancy also includes illicit drugs, of course. -unfortunately, use of illicit drugs, such as cocaine and mari- juana, is common among some pregnant women. -drugs of abuse, such as cocaine, easily cross the placenta and impair fetal growth and development. -furthermore, they are responsible for preterm births, low-birthweight infants, perinatal deaths, and sudden infant deaths. -if these newborns survive, central nervous system damage is evident: their cries, sleep, and behaviors early in life are abnormal, and their cognitive development later in life is impaired.56 they may be hypersensitive or underaroused; those who test positive for drugs suffer the greatest effects of toxicity and withdrawal. -smoking and chewing tobacco unfortunately, an estimated one out of nine pregnant women in the united states smokes, with higher rates for older teens.57 smoking cigarettes and chewing tobacco at any time exert harmful effects, and pregnancy dramatically magnifies the hazards of these practices. -smoking restricts the blood supply to the growing fetus and thus limits oxygen and nutrient delivery and waste removal. -a mother who smokes is more likely to have a complicated birth and a low-birthweight infant. -indeed, of all preventable causes of low birthweight in the united states, smoking is at the top of the list. -although, most infants born to cigarette smokers are low birthweight, some are not, suggesting that the effect of smoking on birthweight also depends, in part, on genes involved in the metabolism of smoking toxins.58 life cycle nutrition: pregnancy and lactation 531 in addition to contributing to low birthweight, smoking interferes with lung growth and increases the risks of respiratory infections and childhood asthma.59 it can also cause death in an otherwise healthy fetus or newborn. -a positive relation- ship exists between sudden infant death syndrome (sids) and both cigarette smoking during pregnancy and postnatal exposure to passive smoke.60 smoking during pregnancy may even harm the intellectual and behavioral development of the child later in life. -the margin lists other complications of smoking during pregnancy. -infants of mothers who chew tobacco also have low birthweights and high rates of fetal deaths. -any woman who smokes cigarettes or chews tobacco and is consid- ering pregnancy or who is already pregnant should try to quit. -environmental contaminants proving that environmental contaminants cause reproductive damage is difficult, but evidence in wildlife is established and seems likely for human beings.61 infants and young children of pregnant women exposed to environmental contaminants such as lead show signs of delayed mental and psychomotor development. -during pregnancy, lead readily moves across the placenta, inflicting severe damage on the developing fetal nervous system.62 in ad- dition, infants exposed to even low levels of lead during gestation weigh less at birth and consequently struggle to survive. -for these reasons, it is particularly important that pregnant women receive foods and beverages grown and prepared in environ- ments free of contamination. -a diet high in calcium will help to defend against lead contamination, and breastfeeding may help to counterbalance developmental damage incurred from contamination during pregnancy.63 mercury is among the contaminants of concern. -as chapter 5 mentioned, fatty fish are a good source of omega-3 fatty acids, but some fish contain large amounts of the pollutant mercury, which can harm the developing brain and nervous sys- tem.64 because the benefits of moderate fish consumption outweigh the risks, preg- nant (and lactating) women should do the following:65 avoid shark, swordfish, king mackerel, and tilefish (also called golden snap- per or golden bass). -limit average weekly consumption to 12 ounces (cooked or canned) of seafood or to 6 ounces (cooked or canned) of white (albacore) tuna. -supplements of fish oil are not recommended because they may contain concen- trated toxins and because their effects on pregnancy remain unknown. -foodborne illness as chapter 19 explains, foodborne illnesses arise when peo- ple eat foods that contain infectious microbes or microbes that produce toxins. -at best, the vomiting and diarrhea associated with these illnesses can leave a pregnant woman exhausted and dehydrated; at worse, foodborne illnesses can cause menin- gitis, pneumonia, or even fetal death. -pregnant women are about 20 times more likely than other healthy adults to get the foodborne illness listeriosis. -the margin presents tips to prevent listeriosis, and chapter 19 includes precautions to mini- mize the risks of other common foodborne illness. -dietary guidelines for americans 2005 pregnant women should not eat or drink unpasteurized milk, milk prod- ucts, or juices; raw or undercooked eggs, meat, or poultry; or raw sprouts. -pregnant women should only eat certain deli meats and frankfurters that have been reheated to steaming hot. -vitamin-mineral megadoses the pregnant woman who is trying to eat well may mistakenly assume that more is better when it comes to vitamin-mineral sup- plements. -this is simply not true; many vitamins and minerals are toxic when taken complications associated with smoking during pregnancy: fetal growth retardation low birthweight complications at birth (prolonged final stage of labor) mislocation of the placenta premature separation of the placenta vaginal bleeding spontaneous abortion fetal death sudden infant death syndrome (sids) middle ear diseases cardiac and respiratory diseases listeriosis can be prevented in the following ways: use only pasteurized juices and dairy products; avoid mexican soft cheeses, feta cheese, brie, camembert, and blue-veined cheeses such as roquefort. -thoroughly cook meat, poultry, eggs, and seafood. -thoroughly reheat hot dogs, luncheon meats, and deli meats, including cured meats such as salami. -wash all fruits and vegetables. -avoid refrigerated p t , meat spreads, smoked seafood such as salmon or trout, and any fish labeled nova, lox, or kippered, unless prepared in a cooked dish. -sudden infant death syndrome (sids): the unexpected and unexplained death of an apparently well infant; the most common cause of death of infants between the second week and the end of the first year of life; also called crib death. -listeriosis: an infection caused by eating food contaminated with the bacterium listeria monocytogenes, which can be killed by pasteurization and cooking but can survive at refrigerated temperatures; certain ready- to-eat foods, such as hot dogs and deli meats, may become contaminated after cooking or processing, but before packaging. -532 chapter 15 in excess. -excessive vitamin a is particularly infamous for its role in malformations of the cranial nervous system. -intakes before the seventh week appear to be the most damaging. -(review figure 15-4 on p. 512 to see how many tissues are in their criti- cal periods prior to the seventh week.) -for this reason, vitamin a supplements are not given during pregnancy unless there is specific evidence of deficiency, which is rare. -a pregnant woman can obtain all the vitamin a and most of the other vita- mins and minerals she needs by making wise food choices. -she should take supple- ments only on the advice of a registered dietitian or physician. -caffeine caffeine crosses the placenta, and the developing fetus has a limited ability to metabolize it. -research studies have not proved that caffeine (even in high doses) causes birth defects in human infants (as it does in animals), but some evi- dence suggests that heavy use increases the risk of fetal death.66 (in these studies, heavy caffeine use is defined as the equivalent of eight or more cups of coffee a day.) -all things considered, it is most sensible to limit caffeine consumption to the equiv- alent of a cup of coffee or two 12-ounce cola beverages a day. -(the caffeine contents of selected beverages, foods, and drugs are listed at the beginning of appendix h.) weight-loss dieting weight-loss dieting, even for short periods, is hazardous during pregnancy. -low-carbohydrate diets or fasts that cause ketosis deprive the fe- tal brain of needed glucose and may impair cognitive development. -such diets are also likely to lack other nutrients vital to fetal growth. -regardless of prepregnancy weight, pregnant women should never intentionally lose weight. -sugar substitutes artificial sweeteners have been extensively investigated and found to be acceptable during pregnancy if used within fda s guidelines (presented in highlight 4).67 still, it is prudent for pregnant women to use sweeteners in moder- ation and within an otherwise nutritious and well-balanced diet. -women with phenylketonuria should not use aspartame, as highlight 4 explained. -in summary high-risk pregnancies, especially for teenagers, threaten the life and health of both mother and infant. -proper nutrition and abstinence from smoking, alco- hol, and other drugs improve the outcome. -in addition, prenatal care includes monitoring pregnant women for gestational diabetes and preeclampsia. -in general, the following guidelines will allow most women to enjoy a healthy pregnancy:68 get prenatal care. -eat a balanced diet, safely prepared. -take prenatal supplements as prescribed. -gain a healthy amount of weight. -refrain from cigarettes, alcohol, and drugs (including herbs, unless pre- scribed by a physician). -childbirth marks the end of pregnancy and the beginning of a new set of parental responsibilities including feeding the newborn. -nutrition during lactation to learn about breastfeeding, a pregnant woman can read at least one of the many books available. -at the end of this chapter, nutrition on the net provides a list of resources, including laleche league international. -before the end of her pregnancy, a woman needs to consider whether to feed her in- fant breast milk, infant formula, or both. -these options are the only recom- mended foods for an infant during the first four to six months of life. -the rate of breastfeeding is close to the healthy people 2010 goal of 75 percent at birth, but it falls far short of goals at six months and a year.69 this section focuses on how the life cycle nutrition: pregnancy and lactation 533 mother s nutrition supports the making of breast milk, and the next chapter de- scribes how the infant benefits from drinking breast milk. -in many countries around the world, a woman breastfeeds her newborn with- out considering the alternatives or making a conscious decision. -in other parts of the world, a woman feeds her newborn formula simply because she knows so little about breastfeeding. -she may have misconceptions or feel uncomfortable about a process she has never seen or experienced. -breastfeeding offers many health benefits to both mother and infant, and every pregnant woman should seriously consider it (see table 15-4).70 even so, there are sometimes valid rea- sons for not breastfeeding, and formula-fed infants grow and develop into healthy children. -lactation: a physiological process lactation naturally follows pregnancy, as the mother s body continues to nourish the infant. -the mammary glands secrete milk for this purpose. -the mammary glands develop during puberty but remain fairly inactive until pregnancy. -during pregnancy, hormones promote the growth and branching of a duct system in the breasts and the development of the milk-producing cells. -the hormones prolactin and oxytocin finely coordinate lactation. -the infant s demand for milk stimulates the release of these hormones, which signal the mammary glands to supply milk. -prolactin is responsible for milk production. -as long as the in- fant is nursing, prolactin concentrations remain high, and milk production continues. -the hormone oxytocin causes the mammary glands to eject milk into the ducts, a response known as the let-down reflex. -the mother feels this reflex as a con- traction of the breast, followed by the flow of milk and the release of pressure. -by relaxing and eating well, the nursing mother promotes easy let-down of milk and greatly enhances her chances of successful lactation. -table 15-4 benefits of breastfeeding for infants: provides the appropriate composition and balance of nutrients with high bioavailability provides hormones that promote physiological development improves cognitive development protects against a variety of infections may protect against some chronic diseases, such as diabetes (both types), obesity, atherosclerosis, asthma, and hypertension, later in life protects against food allergies for mothers: contracts the uterus delays the return of regular ovulation, thus lengthening birth intervals (is not, however, a dependable method of contraception) conserves iron stores (by prolonging amenorrhea) may protect against breast and ovarian cancer and reduce the risk of diabetes (type 2) other: cost savings from not needing medical treatment for childhood illnesses or time off work to care for them cost savings from not needing to purchase formula (even after adjusting for added foods in the diet of a lactating mother)a environmental savings to society from not needing to manufacture, package, and ship formula and dispose of the packaging convenience of not having to shop for and prepare formula aa nursing mother produces more than 35 gallons of milk during the first six months, saving roughly $450 in formula costs. -i s b r o c / y e l l e k s l e i r a a women who decides to breastfeed offers her infant a full array of nutrients and protective factors to support optimal health and development. -lactation: production and secretion of breast milk for the purpose of nourishing an infant. -mammary glands: glands of the female breast that secrete milk. -prolactin (pro-lak-tin): a hormone secreted from the anterior pituitary gland that acts on the mammary glands to promote the production of milk. -the release of prolactin is mediated by prolactin-inhibiting hormone (pih). -pro = promote lacto = milk oxytocin (ock-see-toh-sin): a hormone that stimulates the mammary glands to eject milk during lactation and the uterus to contract during childbirth. -let-down reflex: the reflex that forces milk to the front of the breast when the infant begins to nurse. -534 chapter 15 some hospitals employ certified lactation consultants who specialize in helping new mothers establish a healthy breastfeeding relationship with their newborn. -these con- sultants are often registered nurses with specialized training in breast and infant anatomy and physiology. -a jog through the park provides an opportu- nity for physical activity and fresh air. -breastfeeding: a learned behavior lactation is an automatic physiological process that virtually all mothers are capa- ble of doing. -breastfeeding, on the other hand, is a learned behavior that not all mothers decide to do. -of women who do breastfeed, those who receive early and re- peated information and support breastfeed their infants longer than others. -health care professionals play an important role in providing encouragement and accu- rate information on breastfeeding.71 women who have been successful breastfeed- ing can offer advice and dispel misperceptions about lifestyle issues. -table 15-5 lists ten steps maternity facilities and health care professionals can take to promote suc- cessful breastfeeding among new mothers.72 the mother s partner also plays an important role in encouraging breastfeed- ing.73 when partners support the decision, mothers are more likely to start and continue breastfeeding. -clearly, educating those closest to the mother could change attitudes and promote breastfeeding. -most healthy women who want to breastfeed can do so with a little preparation. -physical obstacles to breastfeeding are rare, although most nursing mothers quit before the recommended six months because of perceived difficulties.74 obese mothers seem to have a particularly difficult time, perhaps because of reduced pro- lactin levels.75 successful breastfeeding requires adequate nutrition and rest. -this, plus the support of all who care, will help to enhance the well-being of mother and infant. -maternal energy and nutrient needs during lactation ideally, the mother who chooses to breastfeed her infant will continue to eat nutri- ent-dense foods throughout lactation. -an adequate diet is needed to support the stamina, patience, and self-confidence that nursing an infant demands. -energy intake and exercise a nursing mother produces about 25 ounces of milk per day, with considerable variation from woman to woman and in the same woman from time to time, depending primarily on the infant s demand for milk. -to produce an adequate supply of milk, a woman needs extra energy almost 500 table 15-5 ten steps to successful breastfeeding to promote breastfeeding, every maternity facility should: develop a written breastfeeding policy that is routinely communicated to all health care staff train all health care staff in the skills necessary to implement the breastfeeding policy inform all pregnant women about the benefits and management of breastfeeding help mothers initiate breastfeeding within 1 2 hour of birth show mothers how to breastfeed and how to maintain lactation, even if they need to be separated from their infants give newborn infants no food or drink other than breast milk, unless medically indicated practice rooming-in, allowing mothers and infants to remain together 24 hours a day encourage breastfeeding on demand give no artificial nipples or pacifiers to breastfeeding infantsa s i b r o c / y r u . -m y d n a r foster the establishment of breastfeeding support groups and refer mothers to them at discharge from the facility acompared with nonusers, infants who use pacifiers breastfeed less frequently and stop breastfeeding at a younger age. -c. g. victora and coauthors, pacifier use and short breastfeeding duration: cause, consequence, or coincidence? -pediatrics 99 (1997): 445 453. source: united nations children s fund and world health organization, protecting, promoting and supporting breastfeeding: the special role of maternity services. -life cycle nutrition: pregnancy and lactation 535 energy requirement during lactation: 1st 6 mo: +330 kcal/day 2nd 6 mo: +400 kcal/day kcalories a day above her regular need during the first six months of lactation. -to meet this energy need, she can eat an extra 330 kcalories of food each day and let the fat reserves she accumulated during pregnancy provide the rest. -most women need at least 1800 kcalories a day to receive all the nutrients required for successful lactation. -severe energy restriction may hinder milk production. -after the birth of the infant, many women actively try to lose the extra weight and body fat they accumulated during pregnancy.76 opinions differ as to whether breastfeeding helps with postpartum weight loss. -lactating women may lose body fat more slowly than nonlactating women, but the rate of weight loss is about the same.77 in general, most women lose one to two pounds a month during the first four to six months of lactation; some may lose more, and others may maintain or even gain weight. -neither the quality nor the quantity of breast milk is adversely affected by moderate weight loss, and infants grow normally. -dietary guidelines for americans 2005 moderate weight reduction is safe for breastfeeding women and does not compromise weight gain of the nursing infant. -women often exercise to lose weight and improve fitness, and this is compatible with breastfeeding and infant growth. -because intense physical activity can raise the lactate concentration of breast milk and influence the milk s taste, some infants may prefer milk produced prior to exercise. -in these cases, mothers can either breastfeed before exercise or express their milk before exercise for use afterward. -dietary guidelines for americans 2005 neither acute nor regular exercise adversely affects the mother s ability to successfully breastfeed. -energy nutrients recommendations for protein and fatty acids intakes remain about the same during lactation as during pregnancy, but they increase for carbo- hydrates and fibers. -nursing mothers need additional carbohydrate to replace the glucose used to make the lactose in breast milk. -the fiber recommendation is 1 gram higher simply because it is based on kcalorie intake, which increases during lactation. -vitamins and minerals a question often raised is whether a mother s milk may lack a nutrient if she fails to get enough in her diet. -the answer differs from one nu- trient to the next, but in general, nutritional inadequacies reduce the quantity, not the quality, of breast milk. -women can produce milk with adequate protein, carbo- hydrate, fat, and most minerals, even when their own supplies are limited. -for these nutrients and for the vitamin folate as well, milk quality is maintained at the ex- pense of maternal stores. -this is most evident in the case of calcium: dietary calcium has no effect on the calcium concentration of breast milk, but maternal bones lose some density during lactation if calcium intakes are inadequate.78 bone density in- creases again when lactation ends; breastfeeding has no long-term harmful effects on bones.79 the nutrients in breast milk that are most likely to decline in response to prolonged inadequate intakes are the vitamins especially vitamins b6, b12, a, and d. review figure 15-10 (p. 521) to compare a lactating woman s nutrient needs with those of pregnant and nonpregnant women. -water despite misconceptions, a mother who drinks more fluid does not produce more breast milk. -to protect herself from dehydration, however, a lactating woman nutritious foods support successful lactation. -s e g a m i y t t e g / c s i d o t o h p 536 chapter 15 ai for total water (including drinking water, other beverages, and foods) during lacta- tion: 3.8 l/day needs to drink plenty of fluids. -a sensible guideline is to drink a glass of milk, juice, or water at each meal and each time the infant nurses. -nutrient supplements most lactating women can obtain all the nutrients they need from a well-balanced diet without taking vitamin-mineral supplements. -nev- ertheless, some may need iron supplements, not to enhance the iron in their breast milk, but to refill their depleted iron stores. -the mother s iron stores dwindle during pregnancy as she supplies the developing fetus with enough iron to last through the first four to six months of the infant s life. -in addition, childbirth may have incurred blood losses. -thus woman may need iron supplements during lactation even though, until menstruation resumes, her iron requirement is about half that of other nonpregnant women her age. -food assistance programs in general, women most likely to participate in the food assistance program wic those who are poor and have little education are less likely to breastfeed. -furthermore, wic provides infant formula at no cost. -because wic recognizes the many benefits of breastfeeding, efforts are made to overcome this dilemma. -in addition to nutrition education, breastfeeding mothers receive the fol- lowing wic incentives: higher priority in certification into wic longer eligibility to participate in wic more foods and larger quantities breast pumps and other support materials together, these efforts help to provide nutrition support and encourage wic moth- ers to breastfeed. -particular foods foods with strong or spicy flavors (such as garlic) may alter the flavor of breast milk. -a sudden change in the taste of the milk may annoy some in- fants. -familiar flavors may enhance enjoyment. -infants who develop symptoms of food allergy may be more comfortable if the mother s diet excludes the most common offenders cow s milk, eggs, fish, peanuts, and tree nuts. -generally, infants with a strong family history of food allergies ben- efit from breastfeeding. -a nursing mother can usually eat whatever nutritious foods she chooses. -if she suspects a particular food is causing the infant discomfort, her physician may rec- ommend a dietary challenge: eliminate the food from the diet to see if the infant s reactions subside; then return the food to the diet, and again monitor the infant s reactions. -if a food must be eliminated for an extended time, appropriate substitu- tions must be made to ensure nutrient adequacy. -maternal health if a woman has an ordinary cold, she can continue nursing without worry. -if suscep- tible, the infant will catch it from her anyway. -(thanks to the immunological protec- tion of breast milk, the baby may be less susceptible than a formula-fed baby would be.) -with appropriate treatment, a woman who has an infectious disease such as tu- berculosis or hepatitis can breastfeed; transmission is rare.80 women with hiv (hu- man immunodeficiency virus) infections, however, should consider other options. -hiv infection and aids mothers with hiv infections can transmit the virus (which causes aids) to their infants through breast milk, especially during the early months of breastfeeding.81 where safe alternatives are available, hiv-positive women should not breastfeed their infants. -in developing countries, where the feed- ing of inappropriate or contaminated formulas causes 1.5 million infant deaths each year, the decision is less obvious. -to prevent the mother-to-child transmission of hiv, who and unicef urge mothers in developing countries not to breastfeed. -however, they stress the importance of finding suitable feeding alternatives to pre- life cycle nutrition: pregnancy and lactation 537 vent the malnutrition, disease, and death that commonly occur when women in these countries do not breastfeed. -diabetes women with diabetes (type 1) may need careful monitoring and coun- seling to ensure successful lactation. -these women need to adjust their energy in- takes and insulin doses to meet the heightened needs of lactation. -maintaining good glucose control helps to initiate lactation and support milk production. -postpartum amenorrhea women who breastfeed experience prolonged post- partum amenorrhea. -absent menstrual periods, however, do not protect a woman from pregnancy. -to prevent pregnancy, a couple must use some form of con- traception. -breastfeeding women who use oral contraceptives should use progestin- only agents for at least the first six months.82 estrogen-containing oral contracep- tives reduce the volume and the protein content of breast milk. -breast health some women fear that breastfeeding will cause their breasts to sag. -the breasts do swell and become heavy and large immediately after the birth, but even when they produce enough milk to nourish a thriving infant, they even- tually shrink back to their prepregnant size. -given proper support, diet, and exer- cise, breasts often return to their former shape and size when lactation ends. -breasts change their shape as the body ages, but breastfeeding does not accelerate this process. -whether the physical and hormonal events of pregnancy and lactation protect women from later breast cancer is an area of active research.83 some research sug- gests no association between breastfeeding and breast cancer, whereas other re- search suggests a protective effect. -protection against breast cancer is most apparent for premenopausal women who were young when they breastfed and who breastfed for a long time. -practices incompatible with lactation some substances impair milk production or enter breast milk and interfere with in- fant development. -this section discusses practices that a breastfeeding mother should avoid. -alcohol alcohol easily enters breast milk, and its concentration peaks within an hour of ingestion. -infants drink less breast milk when their mothers have consumed even small amounts of alcohol (equivalent to a can of beer). -three possible reasons, acting separately or together, may explain why. -for one, the alcohol may have al- tered the flavor of the breast milk and thereby the infants acceptance of it. -for an- other, because infants metabolize alcohol inefficiently, even low doses may be potent enough to suppress their feeding and cause sleepiness. -third, the alcohol may have interfered with lactation by inhibiting the hormone oxytocin. -in the past, alcohol has been recommended to mothers to facilitate lactation de- spite a lack of scientific evidence that it does so. -the research summarized here sug- gests that alcohol actually hinders breastfeeding. -an occasional alcoholic beverage may be within safe limits, but breastfeeding should be avoided for at least two hours afterwards. -medicinal drugs most medicines are compatible with breastfeeding, but some are contraindicated, either because they suppress lactation or because they are secreted into breast milk and can harm the infant.84 as a precaution, a nursing mother should consult with her physician prior to taking any drug, including herbal supplements. -illicit drugs illicit drugs, of course, are harmful to the physical and emotional health of both the mother and the nursing infant. -breast milk can deliver such high doses of illicit drugs as to cause irritability, tremors, hallucinations, and even death in infants. -women whose infants have overdosed on illicit drugs contained in breast milk have been convicted of murder. -postpartum amenorrhea: the normal temporary absence of menstrual periods immediately following childbirth. -538 chapter 15 smoking because cigarette smoking reduces milk volume, smokers may produce too little milk to meet their infants energy needs. -the milk they do produce contains nicotine, which alters its smell and flavor. -consequently, infants of breastfeeding mothers who smoke gain less weight than infants of those who do not smoke. -fur- thermore, infant exposure to passive smoke negates the protective effect breastfeed- ing offers against sids and increases the risks dramatically. -environmental contaminants chapter 19 discusses environmental contaminants in the food supply. -some of these environmental contaminants, such as ddt, pcbs, and dioxin, can find their way into breast milk. -inuit mothers living in arctic qu bec who eat seal and beluga whale blubber have high concentrations of ddt and pcbs in their breast milk, but the impact on infant development is unclear. -preliminary studies indicate that the children of these inuit mothers are developing normally. -re- searchers speculate that the abundant omega-3 fatty acids of the inuit diet may pro- tect against damage to the central nervous system. -breast milk tainted with dioxins interferes with tooth development during early infancy, producing soft, mottled teeth that are vulnerable to dental caries. -to limit mercury intake, lactating women should heed the fish restrictions mentioned earlier for pregnant women (see p. 531). -caffeine caffeine enters breast milk and may make an infant irritable and wake- ful. -as during pregnancy, caffeine consumption should be moderate the equiva- lent of one to two cups of coffee a day. -larger doses of caffeine may interfere with the bioavailability of iron from breast milk and impair the infant s iron status. -in summary the lactating woman needs extra fluid and enough energy and nutrients to produce about 25 ounces of milk a day. -breastfeeding is contraindicated for those with hiv/aids. -alcohol, other drugs, smoking, and contaminants may reduce milk production or enter breast milk and impair infant development. -this chapter has focused on the nutrition needs of the mother during pregnancy and lactation. -the next chapter explores the dietary needs of infants, children, and adolescents. -www.thomsonedu.com/thomsonnow nutrition portfolio the choices a woman makes in preparation for, and in support of, pregnancy and lactation can influence both her health and her infant s development today and for decades to come. -for women of childbearing age, determine whether you consume at least 400 micrograms of dietary folate equivalents daily. -for women who are pregnant, evaluate whether you are meeting your nutrition needs and gaining the amount of weight recommended. -for women who are about to give birth, carefully consider all the advantages of breastfeeding your infant and obtain the needed advice to support you. -life cycle nutrition: pregnancy and lactation 539 nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 15, then to nutrition on the net. -visit the pregnancy and child health center of the mayo clinic: www.mayohealth.org learn more about having a healthy baby and about birth defects from the march of dimes and the national center on birth defects and developmental disabilities: www.modimes.org and www.cdc.gov/ncbddd search for pregnancy at the american dietetic association site: www.eatright.org learn more about the wic program: www.fns.usda.gov/fns visit the american college of obstetricians and gynecologists: www.acog.org learn more about gestational diabetes from the american diabetes association: www.diabetes.org learn more about neural tube defects from the spina bi- learn more about breastfeeding from laleche league fida association of america: www.sbaa.org international: www.lalecheleague.org search for birth defects, pregnancy, adolescent preg- obtain prenatal nutrition guidelines from health canada: nancy, maternal and infant health, and breastfeeding at the u.s. government health information site: www.healthfinder.gov www.hc-sc.gc.ca study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -10. what practices should be avoided during pregnancy? -why? -(pp. -530 532) these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. describe the placenta and its function. -(p. 510) 2. describe the normal events of fetal development. -how does malnutrition impair fetal development? -(pp. -510 512, 527) 3. define the term critical period. -how do adverse influences during critical periods affect later health? -(pp. -512 515) 4. explain why women of childbearing age need folate in their diets. -how much is recommended, and how can women ensure that these needs are met? -(pp. -513 515) 5. what is the recommended pattern of weight gain during pregnancy for a woman at a healthy weight? -for an underweight woman? -for an overweight woman? -(pp. -516 518) 6. what does a pregnant woman need to know about exer- cise? -(pp. -518 519) 7. which nutrients are needed in the greatest amounts during pregnancy? -why are they so important? -describe wise food choices for the pregnant woman. -(pp. -519 523) 8. define low-risk and high-risk pregnancies. -what is the significance of infant birthweight in terms of the child s future health? -(pp. -525 526) 9. describe some of the special problems of the pregnant adolescent. -which nutrients are needed in increased amounts? -(p. 529) 11. how do nutrient needs during lactation differ from nutrient needs during pregnancy? -(pp. -521, 534 536) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 542. -1. the spongy structure that delivers nutrients to the fetus and returns waste products to the mother is called the: a. embryo. -b. uterus. -c. placenta. -d. amniotic sac. -2. which of these strategies is not a healthy option for an overweight woman? -a. limit weight gain during pregnancy. -b. postpone weight loss until after pregnancy. -c. follow a weight-loss diet during pregnancy. -d. try to achieve a healthy weight before becoming pregnant. -3. a reasonable weight gain during pregnancy for a normal- weight woman is about: a. -10 pounds. -b. -20 pounds. -c. 30 pounds. -d. 40 pounds. -4. energy needs during pregnancy increase by about: a. -100 kcalories/day. -b. -300 kcalories/day. -c. 500 kcalories/day. -d. 700 kcalories/day. -540 chapter 15 5. to help prevent neural tube defects, grain products are now fortified with: a. iron. -b. folate. -c. protein. -d. vitamin c. 6. pregnant women should not take supplements of: a. iron. -b. folate. -c. vitamin a. d. vitamin c. 7. the combination of high blood pressure, protein in the 8. to facilitate lactation, a mother needs: a. about 5000 kcalories a day. -b. adequate nutrition and rest. -c. vitamin and mineral supplements. -d. a glass of wine or beer before each feeding. -9. a breastfeeding woman should drink plenty of water to: a. produce more milk. -b. suppress lactation. -c. prevent dehydration. -d. dilute nutrient concentration. -10. a woman may need iron supplements during lactation: a. to enhance the iron in her breast milk. -b. to provide iron for the infant s growth. -c. to replace the iron in her body s stores. -d. to support the increase in her blood volume. -urine, and edema signals: a. jaundice. -b. preeclampsia. -c. gestational diabetes. -d. gestational hypertension. -references 1. recommendations to improve preconcep- tion health and health care united states, morbidity and mortality weekly report 55 (2006): 1-23. -2. m. j. davies, evidence for effects of weight on reproduction in women, reproductive biomedicine online 12 (2006): 552-561. -3. m. sallmen and coauthors, reduced fertility among overweight and obese men, epidemi- ology 17 (2006): 520-523; h. i. kort and coauthors, impact of body mass index values on sperm quantity and quality, journal of andrology 27 (2006): 450-452. -4. r. pasquali and a. gambineri, metabolic effects of obesity on reproduction, reproduc- tive biomedicine online 12 (2006): 542-551. -5. r. m. sharpe and s. franks, environment, lifestyle and infertility an inter-generational issue, nature cell biology 4 (2002): s33-s40. -6. j. c. cross and l. mickelson, nutritional influences on implantation and placental development, nutrition reviews 64 (2006): s12-s18. -7. r. 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it affect pregnancy outcomes? -american journal of maternal child nursing 28 (2003): 183-189. -43. l. h. allen, multiple micronutrients in pregnancy and lactation: an overview, american journal of clinical nutrition 81 (2005): 1206s-1212s. -44. p. j. surkan and coauthors, previous preterm and small-for-gestational-age births and the subsequent risk of stillbirth, new england journal of medicine 350 (2004): 777-785. -45. r. j. kaaja and i. a. greer, manifestations of chronic disease during pregnancy, journal of the american medical association 294 (2005): 2751-2757. -46. w. van wootten and r. e. turner, macroso- mia in neonates of mothers with gestational diabetes is associated with body mass index and previous gestational diabetes, journal of the american dietetic association 102 (2002): 241-243. -47. american diabetes association, diagnosis and classification of diabetes mellitus, diabetes care 29 (2006): s43-s48; report of the expert committee on the diagnosis and classification of diabetes mellitus, diabetes care 26 (2003): s5-s20. -48. position statement from the american diabetes association: gestational diabetes mellitus, diabetes care 26 (2003): s103-s105. -49. c. a. crowther and coauthors, effect of treatment of gestational diabetes mellitus on pregnancy outcomes, new england jour- nal of medicine 352 (2005): 2477-2486; o. langer and coauthors, overweight and obese in gestational diabetes: the impact on pregnancy outcomes, american journal of obstetrics and gynecology 192 (2005): 1768-1776. -50. c. g. solomon and e. w. seely, preeclamp- sia searching for the cause, new england journal of medicine 350 (2004): 641-642. -51. c. b. rudra and coauthors, perceived exer- tion during prepregnancy physical activity and preeclampsia risk, medicine and science in sports and exercise 37 (2005): 1836-1841; t. l. weissgerber, l. a. wolfe, and g. a. l. davies, the role of regular physical activity in preeclampsia prevention, medicine and science in sports and exercise 36 (2004): 2024-2031. -52. j. d. klein and the committee on adoles- cence, adolescent pregnancy: current trends and issues, pediatrics 116 (2005): 281-286. -53. r. j. paulson and coauthors, pregnancy in the sixth decade of life obstetric outcomes in women of advanced reproductive age, journal of the american medical association 288 (2002): 2320-2323. -54. s. c. tough and coauthors, delayed child- bearing and its impact on population rate changes in lower birth weight, multiple birth, and preterm delivery, pediatrics 109 (2002): 399-403. -55. alcohol consumption among women who are pregnant or who might become pregnant united states, 2002, morbidity and mortality weekly report 53 (2004): 1178-1181. -56. l. t. singer and coauthors, cognitive and motor outcomes of cocaine-exposed infants, journal of the american medical association 287 (2002): 1952-1960. -57. smoking during pregnancy united states, 1990-2002, morbidity and mortality weekly report 53 (2004): 911-915. -58. x. wang and coauthors, maternal cigarette smoking, metabolic gene polymorphism, and infant birth weight, journal of the ameri- can medical association 287 (2002): 195-202. -59. j. r. difranza, c. a. aligne, and m. weitz- man, prenatal and postnatal environmental tobacco smoke exposure and children s health, pediatrics 113 (2004): 1007-1015. -60. difranza, aligne, and weitzman, 2004. -61. r. l. brent, s. tanski, and m. weitzman, a pediatric perspective on the unique vulnera- bility and resilience of the embryo and the child to environmental toxicants: the importance of rigorous research concerning age and agent, pediatrics 113 (2004): 935- 944; r. m. sharpe and d. s. irvine, how strong is the evidence of a link between environmental chemicals and adverse effects on human reproductive health? -british medical journal 328 (2004): 447-451. -62. a. gomaa and coauthors, maternal bone lead as an independent risk factor for fetal neurotoxicity: a prospective study, pediatrics 110 (2002): 110-118. -63. n. ribas-fit and coauthors, breastfeeding, exposure to organochlorine compounds, and neurodevelopment in infants, pediatrics 111 (2003): e580-e585. -64. s. e. schober and coauthors, blood mercury levels in us children and women of child- bearing age, 1999-2000, journal of the ameri- can medical association 289 (2003): 1667-1674. -65. d. mozaffarian and e. b. rimm, fish intake, contaminants, and human health: evaluat- ing the risks and the benefits, journal of the american medical association 296 (2006): 1885-1899; institute of medicine report brief, seafood choices: balancing benefits and risks, october 2006. -66. b. h. bech and coauthors, coffee and fetal death: a cohort study with prospective data, american journal of epidemiology 162 (2005): 983-990. -67. position of the american dietetic associa- tion: use of nutritive and nonnutritive sweetners, journal of the american dietetic association 104 (2004): 255-275. -68. position of the american dietetic associa- tion: nutrition and lifestyle for a healthy pregnancy outcome, journal of the american dietetic association 102 (2002): 1479-1490. -69. r. li and coauthors, breastfeeding rates in the united states by characteristics of the child, mother, or family: the 2002 national immunization survey, pediatrics 115 (2005): e31; r. li and coauthors, prevalence of breastfeeding in the united states: the 2001 national immunization survey, pediatrics 111 (2003): 1198-1201; a. s. ryan, z. wen- jun, and a. acosta, breastfeeding continues to increase into the new millennium, pedi- atrics 110 (2002): 1103-1109. -70. american academy of pediatrics, breastfeed- ing and the use of human milk, pediatrics 115 (2005): 496-506; position of the ameri- can dietetic association: promoting and supporting breastfeeding, journal of the american dietetic association 105 (2005): 810-818. -71. k. a. bonuck and coauthors, randomized, controlled trial of a prenatal and postnatal lactation consultant intervention on dura- tion and intensity of breastfeeding up to 12 months, pediatrics 116 (2005): 1413-1426; j. labarere and coauthors, efficacy of breast- feeding support provided by trained clini- cians during an early, routine, preventive visit: a prospective, randomized, open trial of 226 mother-infant pairs, pediatrics 115 (2005): e139; e. m. taveras and coauthors, mothers and clinicians perspectives on breastfeeding counseling during routine preventive visits, pediatrics 113 (2004): e405. -72. s. merten, j. dratva, and u. ackermann- liebrich, do baby-friendly hospitals influ- ence breastfeeding duration on a national level? -pediatrics 116 (2005): e702; a. mere- wood and coauthors, breastfeeding rates in us baby-friendly hospitals: results of a national survey, pediatrics 116 (2005): 628-634. -73. a. pisacane and coauthors, a controlled trial of the father s role in breastfeeding promo- tion, pediatrics 116 (2005): e494; c. l. den- nis, breastfeeding initiation and duration: a 1990-2000 literature review, journal of obstetric, gynecologic and neonatal nursing 31 (2002): 12-32. -74. dennis, 2002. -75. c. a. lovelady, is maternal obesity a cause of poor lactation performance? -nutrition reviews 63 (2005): 352-355. -76. d. a. krummel and coauthors, stages of 542 chapter 15 change for weight management in postpar- tum women, journal of the american dietetic association 104 (2004): 1102-1108. -77. k. s. wosje and h. j. kalkwarf, lactation, weaning, and calcium supplementation: effects on body composition in postpartum women, american journal of clinical nutrition 80 (2004): 423-429. -78. k. o. o brien and coauthors, bone calcium turnover during pregnancy and lactation in women with low calcium diets is associated with calcium intake and circulating insulin- like growth factor 1 concentrations, ameri- can journal of clinical nutrition 83 (2006): 317-323. -79. f. f. bezerra and coauthors, bone mass is recovered from lactation to postweaning in adolescent mothers with low calcium in- takes, american journal of clinical nutrition 80 (2004): 1322-1326; l. m. paton and coauthors, pregnancy and lactation have no long-term deleterious effect on measures of bone mineral in healthy women: a twin study, american journal of clinical nutrition 77 (2003): 707-714. -80. j. s. wang, q. r. zhu, and x. h. wang, breastfeeding does not pose any additional risk of immunoprophylaxis failure on in- fants of hbv carrier mothers, international journal of clinical practice 57 (2003): 100- 102; j. b. hill and coauthors, risk of hepati- tis b transmission in breast-fed infants of chronic hepatitis b carriers, obstetrics and gynecology 99 (2002): 1049-1052; m. l. newell and l. pembrey, mother-to-child transmission of hepatitis c virus infection, drugs of today 38 (2002): 321-337. -81. j. s. read and the committee on pediatric aids, human milk, breastfeeding, and transmission of human immunodeficiency virus type 1 in the united states, pediatrics 112 (2003): 1196-1205. -82. r. lesnewski and l. prine, initiating hor- monal contraception, american family physician 74 (2006): 105-112. -83. s. cnattingius and coauthors, pregnancy characteristics and maternal risk of breast cancer, journal of the american medical asso- ciation 294 (2005): 2474-2480. -84. s. ito and a. lee, drug excretion into breast milk overview, advanced drug delivery reviews 55 (2003): 617-627. answers 1. c 2. c 3. c 4. b 5. b 6. c 7. b 8. b 9. c 10. c highlight 15 highlight fetal alcohol syndrome . -w as chapter 15 mentioned, drinking alcohol during pregnancy endangers the fetus. -alco- hol crosses the placenta freely and deprives the developing fetus of both nutrients and oxygen. -the damaging effects of alcohol on the developing fetus cover a range of abnor- malities referred to as fetal alcohol spec- trum disorder (see the glossary on p. 544).1 those at the most severe end of the spectrum are described as having fetal alcohol syndrome (fas), a cluster of physical, mental, and neurobehavioral symptoms that includes: prenatal and postnatal growth retardation impairment of the brain and central nervous system, with consequent mental retardation, poor motor skills and coor- dination, and hyperactivity . -d , h t i m s & , . -c . -j , n i t r a m , . -s , r e y w d - n a m s e d n a l / p. . -a , h t u g s s i e r t s vented it cannot be treated. -further, be- cause the most severe damage occurs around the time of conception before a woman may even realize that she is pregnant the warning to abstain includes women who may become pregnant. -drinking during pregnancy as mentioned in chapter 15, 1 out of 10 pregnant women drinks alcohol at some time during her pregnancy; 1 out of 50 uses al- cohol frequently and admits to binge drinking.5 when a woman drinks during pregnancy, she causes damage in two ways: di- rectly, by intoxication, and indirectly, by malnutrition. -prior to the abnormalities of the face and skull (see figure h15-1) increased frequency of major birth de- fects: cleft palate, heart defects, and de- fects in ears, eyes, genitals, and urinary system tragically, the damage evident at birth per- sists: children with fas never fully recover.2 each year, as many as 6000 infants are born with fas because their mothers drank too much alcohol during pregnancy.3 in addition, some 4 million infants are born with prenatal alcohol exposure. -the cluster of mental problems associated with prenatal alcohol ex- posure is known as alcohol-related neu- rodevelopmental disorder (arnd), and the physical malformations are referred to as alcohol-related birth defects (arbd). -some children with arbd and arnd have no outward signs; others may be short or have only minor facial abnormalities. -they often go undiagnosed even when they develop learn- ing difficulties in the early school years. -mood disorders and problem behaviors, such as ag- gression, are common.4 the surgeon general states that pregnant women should abstain from alcohol. -absti- nence from alcohol is the best policy for preg- nant women both because alcohol consumption during pregnancy has such severe conse- quences and because fas can only be pre- figure h15-1 typical facial characteristics of fas head small head size forehead narrow, receding forehead nose short upturned nose flattened nose bridge jaw underdeveloped jaw receding chin receding or flattened upper jaw eyes extra skin folds on eyelids drooping eyelids downward slant of eyes unusually small eyes and/or eye openings short-sightedness inability to focus ( wandering eyes ) ears uneven in placement and size poorly formed outer ear backward curve lips absence of groove in upper lip; flat upper lip thin upper lip 543 544 highlight 15 s k r o w e g a m i e h t / i s i n e s . -b n e l l e characteristic facial features may diminish with time, but children with fas typically continue to be short and underweight for their age. -complete formation of the placenta (approximately 12 weeks), al- cohol diffuses directly into the tissues of the developing embryo, causing incredible damage. -(review figure 15-4 on p. 512 and note that the critical periods for most tissues occur during embry- onic development.) -alcohol interferes with the orderly develop- ment of tissues during their critical periods, reducing the number of cells and damaging those that are produced. -the damage of alcohol toxicity during brain development is apparent in its re- duced size and impaired function.6 when alcohol crosses the placenta, fetal blood alcohol rises until it reaches equilibrium with maternal blood alcohol. -the mother may not even appear drunk, but the fetus may be poi- soned. -the fetus s body is small, its detoxification system is imma- ture, and alcohol remains in fetal blood long after it has disappeared from maternal blood. -a pregnant woman harms her unborn child not only by con- suming alcohol but also by not consuming food. -this combina- tion enhances the likelihood of malnutrition and a poorly developed infant. -it is important to realize, however, that malnu- trition is not the cause of fas. -it is true that mothers of fas chil- dren often have unbalanced diets and nutrient deficiencies. -it is also true that malnutrition may augment the clinical signs seen in these children, but it is the alcohol that causes the damage. -an ad- equate diet alone will not prevent fas if alcohol abuse continues. -how much is too much? -a pregnant woman need not have an alcohol-abuse problem to give birth to a baby with fas. -she need only drink in excess of her liver s capacity to detoxify alcohol. -even one drink a day threatens neuro- logical development and behaviors.7 four drinks a day dramatically increase the risk of having an infant with physical malformations. -in addition to total alcohol intake, drinking patterns play an important role. -most fas studies report their findings in terms of average intake per day, but people usually drink more heavily on some days than on others. -for example, a woman who drinks an average of 1 ounce of alcohol (2 drinks) a day may not drink at all during the week, but then have 10 drinks on saturday night, ex- posing the fetus to extremely toxic quantities of alcohol. -whether various drinking patterns incur damage depends on the fre- quency of consumption, the quantity consumed, and the stage of fetal development at the time of each drinking episode. -an occasional drink may be innocuous, but researchers are un- able to say how much alcohol is safe to consume during pregnancy. -for this reason, health care professionals urge women to stop drink- ing alcohol as soon as they realize they are pregnant or better, as soon as they plan to become pregnant. -why take any risk? -only the woman who abstains is sure of protecting her infant from fas. -when is the damage done? -the first month or two of pregnancy is a critical period of fetal de- velopment. -because pregnancy usually cannot be confirmed be- fore five to six weeks, a woman may not even realize she is pregnant during that critical time. -therefore, it is advisable for women who are trying to conceive, or who suspect they might be pregnant, to abstain or curtail their alcohol intakes to ensure a healthy start. -the type of abnormality observed in an fas infant depends on the developmental events occurring at the times of alcohol expo- sure. -during the first trimester, developing organs such as the brain, heart, and kidneys may be malformed. -during the second trimester, the risk of spontaneous abortion increases. -during the third trimester, body and brain growth may be retarded. -g lossary alcohol-related birth defects (arbd): malformations in the skeletal and organ systems (heart, kidneys, eyes, ears) associated with prenatal alcohol exposure. -alcohol-related neurodevelop- mental disorder (arnd): abnormalities in the central nervous system and cognitive development associated with prenatal alcohol exposure. -fetal alcohol spectrum disorder: a range of physical, behavioral, and cognitive abnormalities caused by prenatal alcohol exposure. -fetal alcohol syndrome (fas): a cluster of physical, behavioral, and cognitive abnormalities associated with prenatal alcohol exposure, including facial malformations, growth retardation, and central nervous disorders. -prenatal alcohol exposure: subjecting a fetus to a pattern of excessive alcohol intake characterized by substantial regular use or heavy episodic drinking. -note: see highlight 7 for other alcohol-related terms and information. -male alcohol ingestion may also affect fertility and fetal development.8 ani- mal studies have found smaller litter sizes, lower birthweights, reduced sur- vival rates, and impaired learning ability in the off- spring of males consuming alcohol prior to concep- tion. -an association be- tween paternal alcohol intake one month prior to conception and low infant birthweight is also appar- ent in human beings. -(pa- ternal alcohol intake was defined as an average of 2 or more drinks daily or at least 5 drinks on one occa- sion.) -this relationship was independent of either parent s smoking and of the mother s use of alcohol, caffeine, or other drugs. -children born with fas must live with the long-term consequences of prenatal brain damage. -e g r o e g 5 9 9 1 z t e m n i e t s in view of the damage caused by fas, prevention efforts focus on educating women not to drink during pregnancy.9 everyone should know of the potential dangers. -women who drink alcohol and who are sexually active may benefit from counseling and ef- nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 15, then to highlights nutrition on the net. -visit the national organization on fetal alcohol syndrome: www.nofas.org search for fetal alcohol syndrome at the u.s. govern- ment health information site: www.healthfinder.gov fetal alcohol syndrome 545 o i g g u r r a f w e h t t a m all containers of beer, wine, and liquor warn women not to drink alcoholic beverages during pregnancy because of the risk of birth defects. -fective contraception to prevent pregnancy.10 almost half of all pregnancies are unintended, with many conceived during a binge-drinking episode.11 public service announcements and alcohol beverage warning labels help to raise awareness. -everyone should hear the message loud and clear: don t drink alcohol prior to conception or during pregnancy. -request information on fetal alcohol syndrome from the national clearinghouse for alcohol and drug information: ncadi.samsha.gov request information on drinking during pregnancy from the national institute on alcohol abuse and alcoholism: www.niaaa.nih.gov gather facts on fetal alcohol syndrome from the march of dimes: www.modimes.org references 1. h. e. hoyme and coauthors, a practical clinical approach to diagnosis of fetal alco- hol spectrum disorders: clarification of the 1996 institute of medicine criteria, pedi- atrics 115 (2005): 39 47. -2. n. l. day and coauthors, prenatal alcohol exposure predicts continued deficits in offspring size at 14 years of age, alcoholism: clinical and experimental research 26 (2002): 1584 1591; m. d. cornelius and coauthors, alcohol, tobacco and marijuana use among pregnant teenagers: 6-year follow-up of offspring growth effects, neurotoxicology and teratology 24 (2002): 703 710. -3. guidelines for identifying and referring persons with fetal alcohol syndrome, mor- bidity and mortality weekly report 54 (2005): 1 10. -4. m. j. o connor and coauthors, psychiatric illness in a clinical sample of children with prenatal alcohol exposure, american journal of drug and alcohol abuse 28 (2002): 743 754. -5. alcohol consumption among women who are pregnant or who might become preg- nant united states, 2002, morbidity and mortality weekly report 53 (2004): 1178 1181. -6. j. w. olney and coauthors, the enigma of fetal alcohol neurotoxicity, annals of medi- cine 34 (2002): 109 119. -7. s. w. jacobson and coauthors, validity of maternal report of prenatal alcohol, cocaine, and smoking in relation to neurobehavioral outcome, pediatrics 109 (2002): 815 825. -8. h. klonoff-cohen, p. lam-kruglick, and c. gonzalez, effects of maternal and paternal alcohol consumption on the success rates of in vitro fertilization and gamete intrafallop- ian transfer, fertility and sterility 79 (2003): 330 339. -9. j. r. hankin, fetal alcohol syndrome pre- vention research, alcohol research and health 26 (2002): 58 65. -10.the project choices intervention research group, reducing the risk of alcohol-exposed pregnancies: a study of a motivational intervention in community settings, pedi- atrics 111 (2003): 1131 1135. -11.t. -s. naimi and coauthors, binge drinking in the preconception period and the risk of unintended pregnancy: implications for women and their children, pediatrics 111 (2003): 1136 1141. stephen wilkes/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow how to: practice problems nutrition portfolio journal nutrition in your life much of this book has focused on you your food choices and how they might affect your health. -this chapter shifts the focus from you the recipient to you the caregiver. -one day (if not already), children will depend on you to feed them well and teach them wisely. -the responsibility of nourishing children can seem overwhelming at times, but the job is fairly simple. -offer children a vari- ety of nutritious foods to support their growth, and teach them how to make healthy food and activity choices. -presenting foods in a relaxed and supportive environment nourishes both physical and emotional well-being. -life cycle nutrition: infancy, childhood, and adolescence the first year of life is a time of phenomenal growth and development. -af- ter the first year, a child continues to grow and change, but more slowly. -still, the cumulative effects over the next decade are remarkable. -then, as the child enters the teen years, the pace toward adulthood accelerates dra- matically. -this chapter examines the special nutrient needs of infants, children, and adolescents. -nutrition during infancy initially, the infant drinks only breast milk or formula but later begins to eat some foods, as appropriate. -common sense in the selection of infant foods along with a nurturing, relaxed environment support an infant s health and well-being. -energy and nutrient needs an infant grows fast during the first year, as figure 16-1 shows. -growth directly re- flects nutrient intake and is an important parameter in assessing the nutrition sta- tus of infants and children. -health care professionals measure the heights and weights of infants and children at intervals and compare the measurements with standard growth curves for gender and age and with previous measures of each child (see the how to, p. 548). -energy intake and activity a healthy infant s birthweight doubles by about five months of age and triples by one year, typically reaching 20 to 25 pounds. -the infant s length changes more slowly than weight, increasing about 10 inches from birth to one year. -by the end of the first year, infant growth slows considerably; dur- ing the second year, an infant typically gains less than 10 pounds and grows about 5 inches in height. -not only do infants grow rapidly, but their energy requirement is remarkably high about twice that of an adult, based on body weight. -a newborn baby re- quires about 450 kcalories per day, whereas most adults require about 2000 kcalo- ries per day. -in terms of body weight, the difference is remarkable. -infants require about 100 kcalories per kilogram of body weight per day, whereas most adults need fewer than 40 (see table 16-1, p. 548). -if an infant s energy needs were applied to an adult, a 170-pound adult would require over 7000 kcalories a day. -after six months, the infant s energy needs decline as the growth rate slows, but some of the energy saved by slower growth is spent in increased activity. -c h a p t e r 16 chapter outline nutrition during infancy energy and nutrient needs breast milk infant formula special needs of preterm infants introducing cow s milk introducing solid foods mealtimes with toddlers nutrition during childhood energy and nutrient needs hunger and malnutrition in children the malnutrition- lead connection hyperactivity and hyper behavior food allergy and intolerance childhood obesity meal- times at home nutrition at school nutrition during adolescence growth and development energy and nutrient needs food choices and health habits problems adolescents face highlight 16 childhood obesity and the early development of chronic diseases figure 16-1 weight gain of infants in their first five years of life in the first year, an infant s birthweight may triple, but over the following sev- eral years, the rate of weight gain grad- ually diminishes. ) -b l ( t i h g e w 40 30 20 10 0 1 2 age (yr) 3 4 5 547 548 chapter 16 how to plot measures on a growth chart you can assess the growth of infants and children by plotting their measurements on a percentile graph. -percentile graphs divide the measures of a population into 100 equal divisions so that half of the population falls at or above the 50th percentile and half falls below. -using percentiles allows for compar- isons among people of the same age and gender. -to plot measures on a growth chart, follow these steps: select the appropriate chart based on age and gender. -for this example, use the ac- companying chart, which gives percentiles for weight for girls from birth to 36 months. -(appendix e provides other growth charts for both boys and girls of various ages.) -locate the infant s age along the horizontal axis at the bottom of the chart (in this exam- ple, 6 months). -locate the infant s weight in pounds or kilograms along the vertical axis of the chart (in this example, 17 pounds or 7.7 kilo- grams). -mark the chart where the age and weight lines intersect (shown here with a red dot), and follow the curved line to find the percentile. -this six-month-old infant is at the 75th per- centile. -her pediatrician will weigh her again over the next few months and expect the growth curve to follow the same percentile throughout the first year. -in general, dra- matic changes or measures much above the 80th percentile or much below the 10th percentile may be cause for concern. -source: developed by the national center for health statistics in collaboration with the national center for chronic disease prevention and health promotion (2000). -to practice plotting measures on a growth chart, log on to www.thomsonedu.com/thomsonnow, go to chapter 16, then go to how to. -table 16-1 heart rate, respiration rate, and energy needs compared infant and adult heart rate (beats/minute) infants adults 120 to 140 70 to 80 respiration rate 20 to 40 15 to 20 (breaths/minute) energy needs (kcal/body weight) 45/lb (100/kg) <18/lb (<40/kg) energy nutrients recommendations for the energy nutrients carbohydrate, fat, and protein during the first six months of life are based on the average intakes of healthy, full-term infants fed breast milk.1 during the second six months of life, rec- ommendations reflect typical intakes from solid foods as well as breast milk. -as discussed in chapter 4, carbohydrates provide energy to all the cells of the body, especially those in the brain, which depend primarily on glucose to fuel ac- tivities. -relative to the size of the body, an infant s brain is larger and uses relatively more glucose about 60 percent of the day s total energy intake.2 fat provides most of the energy in breast milk and standard infant formula. -its high energy density supports the rapid growth of early infancy. -no single nutrient is more essential to growth than protein. -all of the body s cells and most of its fluids contain protein; it is the basic building material of the body s tissues. -chapter 6 detailed the problems inadequate protein can cause. -excess di- etary protein can cause problems, too, especially in a small infant. -too much pro- tein stresses the liver and kidneys, which have to metabolize and excrete the excess nitrogen. -signs of protein overload include acidosis, dehydration, diarrhea, ele- vated blood ammonia, elevated blood urea, and fever. -such problems are not com- life cycle nutrition: infancy, childhood, and adolescence 549 mon, but they have been observed in infants fed inappropriate foods, such as fat- free milk or concentrated formula. -vitamins and minerals as with the energy nutrients, the recommendations for the vitamins and minerals are based on the average amount of nutrients consumed by thriving infants breastfed by well-nourished mothers. -an infant s needs for most of these nutrients, in proportion to body weight, are more than double those of an adult. -figure 16-2 illustrates this by comparing a five-month-old infant s needs per unit of body weight with those of an adult man. -some of the differences are extraordinary. -water one of the most essential nutrients for infants, as for everyone, is water. -the younger the infant, the greater the percentage of body weight is water. -during early infancy, breast milk or infant formula normally provides enough water to replace fluid losses in a healthy infant. -even in hot, dry climates, neither breastfed nor bot- tle-fed infants need supplemental water.3 because much of the fluid in an infant s body is located outside the cells between the cells and in the blood vessels rapid fluid losses and the resulting dehydration can be life-threatening. -conditions that cause rapid fluid loss, such as diarrhea or vomiting, require treatment with an elec- trolyte solution designed for infants. -figure 16-2 on the basis of body weight recommended intakes of an infant and an adult compared s e g a m i y t t e g / s e e l d i v a d after six months, energy saved by slower growth is spent in increased activity. -because infants are small, they need smaller total amounts of the nutrients than adults do, but when comparisons are based on body weight, infants need more than twice as much of many nutrients. -infants use large amounts of energy and nutrients, in proportion to their body size, to keep all their metabolic processes going. -recommendations for a male 20 years old 5 times as much per pound as an adult male 10 times as much per pound energy protein vitamin a vitamin d vitamin e vitamin c folate niacin riboflavin thiamin vitamin b6 vitamin b12 calcium phosphorus magnesium iodine iron zinc vitamin d recommendations for an infant are 10 times greater per pound of body weight than those for an adult male. -pound for pound, niacin recommendations for an infant and an adult male are similar. -key: 20-year-old male (160 lb) 5-month-old infant (16 lb) 550 chapter 16 figure 16-3 percentages of energy- yielding nutrients in breast milk and in recommended adult diets the proportions of energy-yielding nutrients in human breast milk differ from those recommended for adults.a 6% 55% protein fat 39% carbohydrate 21% 26% 53% breast milk recommended adult diets athe values listed for adults represent approximate midpoints of the acceptable ranges for protein (10 to 35 percent), fat (20 to 35 percent), and carbohydrate (45 to 65 percent). -chapter 15 discussed breastfeeding, breast- feeding support, reasons why some women choose not to breastfeed, and contraindica- tions to breastfeeding. -alpha-lactalbumin (lact-al-byoo-min): a major protein in human breast milk, as opposed to casein (cay-seen), a major protein in cow s milk. -breast milk in the united states and canada, the two dietary practices that have the most signif- icant effect on an infant s nutrition are the milk the infant receives and the age at which solid foods are introduced. -a later section discusses the introduction of solid foods, but as to the milk, both the american academy of pediatrics (aap) and the canadian paediatric society strongly recommend breastfeeding for healthy full- term infants, except where specific contraindications exist. -the american dietetic association (ada) also advocates breastfeeding for the nutritional health it confers on the infant as well as for the many other benefits it provides both infant and mother (review table 15-4, p. 533).4 breast milk excels as a source of nutrients for infants. -its unique nutrient compo- sition and protective factors promote optimal infant health and development throughout the first year of life. -the aap, the canadian paediatric society, and the ada recommend exclusive breastfeeding for 6 months, and breastfeeding with complementary foods for at least 12 months for infants.5 experts add, though, that iron-fortified formula, which imitates the nutrient composition of breast milk, is an acceptable alternative. -after all, the primary goal is to provide the infant nourish- ment in a relaxed and loving environment. -frequency and duration of breastfeeding breast milk is more easily and completely digested than formula, so breastfed infants usually need to eat more fre- quently than formula-fed infants do. -during the first few weeks, approximately 8 to 12 feedings a day, on demand, as soon as the infant shows early signs of hunger such as increased alertness, activity, or suckling motions, promote optimal milk pro- duction and infant growth.6 crying is a late indicator of hunger. -an infant who nurses every two to three hours and sleeps contentedly between feedings is ade- quately nourished. -as the infant gets older, stomach capacity enlarges and the mother s milk production increases, allowing for longer intervals between feedings. -even though the infant obtains about half the milk from the breast during the first two or three minutes of sucking, breastfeeding is encouraged for about 10 to 15 minutes on each breast. -the infant s sucking, as well as the complete removal of milk from the breast, stimulates lactation. -energy nutrients the energy-nutrient composition of breast milk differs dramat- ically from that recommended for adult diets (see figure 16-3). -yet for infants, breast milk is nature s most nearly perfect food, providing the clear lesson that people at different stages of life have different nutrient needs. -the carbohydrate in breast milk (and infant formula) is the disaccharide lactose. -in addition to being easily digested, lactose enhances calcium absorption. -the amount of protein in breast milk is less than in cow s milk, but this quantity is actually beneficial because it places less stress on the infant s immature kidneys to excrete the major end product of protein metabolism, urea. -much of the protein in breast milk is alpha-lactalbumin, which is efficiently digested and absorbed. -as for the lipids, breast milk contains a generous proportion of the essential fatty acids linoleic acid and linolenic acid, as well as their longer-chain derivatives arachidonic acid and dha (docosahexaenoic acid). -infant formula used to provide only linoleic acid and linolenic acid, but now arachidonic acid and dha are also included.7 infants can make arachidonic acid and dha from linoleic and linolenic acid, respectively, but some infants may need more than they can make. -arachidonic acid and dha are found abundantly in both the retina of the eye and the brain, and research has focused on the visual and mental development of breastfed infants and infants fed standard formula without dha and arachidonic acid added.8 breastfed infants generally score higher on tests of mental develop- ment than formula-fed infants do, and researchers are investigating whether this difference can be attributed to dha and arachidonic acid in breast milk.9 in one study, researchers found no developmental or visual differences between infants fed standard formula and those fed formula with added dha and arachidonic acid.10 in two other studies, however, infants fed the formula fortified with dha and life cycle nutrition: infancy, childhood, and adolescence 551 arachidonic acid formula had sharper vision at one year of age than those who were fed standard formula.11 vitamins with the exception of vitamin d, the vitamins in breast milk are ample to support infant growth. -the vitamin d in breast milk is low, and vitamin d deficiency impairs bone mineralization. -vitamin d deficiency is most likely in infants who are not exposed to sunlight daily, have darkly pigmented skin, and receive breast milk without vitamin d supplementation.12 reports of infants in the united states devel- oping the vitamin d deficiency disease rickets and recommendations by the aap to keep infants under six months of age out of direct sunlight have prompted updated vitamin d guidelines. -the aap now recommends a vitamin d supplement for all in- fants who are breastfed exclusively, and for any infants who do not receive at least 500 milliliters (15 ounces) per day of vitamin d-fortified formula.13 minerals the calcium content of breast milk is ideal for infant bone growth, and the calcium is well absorbed. -breast milk contains relatively small amounts of iron, but the iron has a high bioavailability. -zinc also has a high bioavailability, thanks to the presence of a zinc-binding protein. -breast milk is low in sodium, another ben- efit for immature kidneys. -fluoride promotes the development of strong teeth, but breast milk is not a good source. -supplements pediatricians may routinely prescribe liquid supplements contain- ing vitamin d, iron, and fluoride. -table 16-2 offers a schedule of supplements dur- ing infancy. -in addition, the aap recommends giving a single dose of vitamin k to infants at birth to protect them from bleeding to death. -(see chapter 11 for a descrip- tion of vitamin k s role in blood clotting.) -immunological protection in addition to nutritional benefits, breast milk offers immunological protection. -not only is breast milk sterile, but it actively fights dis- ease and protects infants from illnesses.14 such protection is most valuable during the first year, when the infant s immune system is not fully prepared to mount a re- sponse against infection. -during the first two or three days after delivery, the breasts produce colostrum, a premilk substance containing mostly serum with antibodies and white blood cells. -colostrum (like breast milk) helps protect the newborn from infections against which the mother has developed immunity. -the maternal antibodies swal- lowed with the milk inactivate disease-causing bacteria within the digestive tract before they can start infections. -this explains, in part, why breastfed infants have fewer intestinal infections than formula-fed infants. -in addition to antibodies, colostrum and breast milk provide other powerful agents that help to fight against bacterial infection. -among them are bifidus factors, which favor the growth of the friendly bacterium lactobacillus bifidus table 16-2 supplements for full-term infants breastfed infants: birth to six months of age six months to one year formula-fed infants: birth to six months of age six months to one year vitamin da ironb fluoridec avitamin d supplements are recommended for all infants who are exclusively breastfed and for any infants who do not receive at least 500 milliliters (15 ounces) of vitamin d fortified formula. -binfants four to six months of age need additional iron, preferably in the form of iron-fortified cereal for both breastfed and formula-fed infants and iron-fortified infant formula for formula-fed infants. -cat six months of age, breastfed infants and formula-fed infants who receive ready-to-use formulas (these are prepared with water low in fluoride) or formula mixed with water that contains little or no fluoride (less than 0.3 ppm) need supplements. -source: adapted from committee on nutrition, american academy of pediatrics, pediatric nutrition handbook, 5th ed., ed. -r. e. kleinman (elk grove village, ill.: american academy of pediatrics, 2004). -s i b r o c / y r a r b i l o t o h p s n o i t c e l f e r ; k c o c d o o w e i n n e j women are encouraged to breastfeed whenever possible because breast milk offers infants many nutrient and health advantages. -protective factors in breast milk: antibodies bifidus factors lactoferrin lactadherin growth factor lipase enzyme colostrum (ko-lahs-trum): a milklike secretion from the breast, present during the first day or so after delivery before milk appears; rich in protective factors. -bifidus (biff-id-us, by-feed-us) factors: factors in colostrum and breast milk that favor the growth of the friendly bacterium lactobacillus (lack-toh-ba-sill-us) bifidus in the infant s intestinal tract, so that other, less desirable intestinal inhabitants will not flourish. -552 chapter 16 lactoferrin (lack-toh-ferr-in): a protein in breast milk that binds iron and keeps it from supporting the growth of the infant s intestinal bacteria. -lactadherin (lack-tad-hair-in): a protein in breast milk that attacks diarrhea-causing viruses. -breast milk bank: a service that collects, screens, processes, and distributes donated human milk. -wean: to gradually replace breast milk with infant formula or other foods appropriate to an infant s diet. -in the infant s digestive tract, so that other, harmful bacteria cannot become es- tablished. -an iron-binding protein in breast milk, lactoferrin, keeps bacteria from getting the iron they need to grow, helps absorb iron into the infant s blood- stream, and kills some bacteria directly.15 the protein lactadherin in breast milk binds to, and inhibits replication of, the virus that causes most infant diarrhea.16 breastfeeding also protects against other common illnesses of infancy such as middle ear infection and respiratory illness.17 in addition, a growth factor that is present in breast milk stimulates the development and maintenance of the in- fant s digestive tract and its protective factors. -several breast milk enzymes such as lipase also help protect the infant against infection. -clearly, breast milk is a very special substance. -allergy and disease protection in addition to protection against infection, breast milk may offer protection against the development of allergies. -compared with formula-fed infants, breastfed infants have a lower incidence of allergic reac- tions, such as asthma, recurrent wheezing, and skin rash.18 this protection is espe- cially noticeable among infants with a family history of allergies.19 similarly, breast milk may offer protection against the development of cardiovascular disease. -com- pared with formula-fed infants, breastfed infants have lower blood pressure and lower blood cholesterol as adults.20 other potential benefits breastfeeding may also help protect against excessive weight gain later. -a review of more than 60 published studies investigating the re- lationship between infant feeding and obesity suggests that initial breastfeeding protects against obesity in later life.21 a well-controlled survey of more than 15,000 adolescents and their mothers indicated that those who were mostly breastfed for the first six months of life were less likely to become overweight than those who were fed formula.22 a study of much younger children (three to five years of age), however, found no clear evidence that breastfeeding influences body weight.23 these researchers noted that other factors, especially the mother s weight, strongly predict overweight in children. -many studies suggest a beneficial effect of breastfeeding on intelligence, but when subjected to strict standards of methodology (for example, large sample size and appropriate intelligence testing), the evidence is less convincing.24 neverthe- less, the possibility that breastfeeding may positively affect later intelligence is in- triguing. -it may be that some specific component of breast milk, such as dha, stimulates brain development or that certain factors associated with the feeding process itself promote intellect. -most likely, a combination of factors are involved. -more large, well-controlled studies are needed to confirm the effects, if any, of breastfeeding on later intelligence. -breast milk banks similar to blood banks that collect blood from individuals to give to others in need, breast milk banks receive milk from lactating women who have an abundant supply to give to infants whose own mothers milk is unavailable or insufficient. -the women who donate breast milk are carefully screened to exclude those who smoke cigarettes, use illegal drugs, take medications (including high doses of dietary supplements), drink more than two alcoholic beverages a day, or have communicable diseases. -the breast milk from several donors is pooled to en- sure an even distribution of all components, pasteurized to destroy bacteria, checked for contamination, and frozen before being shipped overnight to hospitals, where it is dispensed by physician prescription. -in the absence of mother s own breast milk, donor milk may be the life saving solution for fragile infants, most notably those with very low birthweight or unusual medical conditions.25 infant formula a woman who breastfeeds for a year can wean her infant to cow s milk, bypassing the need for infant formula. -however, a woman who decides to feed her infant for- life cycle nutrition: infancy, childhood, and adolescence 553 mula from birth, to wean to formula after less than a year of breastfeeding, or to substitute formula for breastfeeding on occasion must select an appropriate infant formula and learn to prepare it. -infant formula composition formula manufacturers attempt to copy the nu- trient composition of breast milk as closely as possible. -figure 16-4 illustrates the en- ergy-nutrient balance of both. -the aap recommends that all formula-fed infants receive iron-fortified infant formulas. -the increasing use of iron-fortified formulas during the past few decades is a major reason for the decline in iron-deficiency ane- mia among u.s. infants. -risks of formula feeding infant formulas contain no protective antibodies for in- fants, but in general, vaccinations, purified water, and clean environments in devel- oped countries help protect infants from infections. -formulas can be prepared safely by following the rules of proper food handling and by using water that is free of con- tamination. -of particular concern is lead-contaminated water, a major source of lead poisoning in infants. -because the first water drawn from the tap each day is highest in lead, a person living in a house with old, lead-soldered plumbing should let the water run a few minutes before drinking or using it to prepare formula or food. -in developing countries and in poor areas of the united states, formula may be unavailable, prepared with contaminated water, or overdiluted in an attempt to save money. -contaminated formulas often cause infections, leading to diarrhea, dehydration, and malabsorption. -without sterilization and refrigeration, formula is an ideal breeding ground for bacteria. -whenever such risks are present, breast- feeding can be a life-saving option: breast milk is sterile, and its antibodies en- hance an infant s resistance to infections. -infant formula standards national and international standards have been set for the nutrient contents of infant formulas. -in the united states, the standard developed by the aap reflects human milk taken from well-nourished mothers during the first or second month of lactation, when the infant s growth rate is high. -the food and drug administration (fda) mandates the safety and nutritional quality of infant formulas. -formulas meeting these standards have similar nutrient compositions. -small differ- ences among formulas are sometimes confusing, but they are usually unimportant. -special formulas standard cow s milk-based formulas are inappropriate for some infants. -special formulas have been designed to meet the dietary needs of infants with specific conditions such as prematurity or inherited diseases. -infants allergic to milk protein can drink special hypoallergenic formulas or formulas based on soy protein.26 soy formulas also use cornstarch and sucrose instead of lactose and so are recommended for infants with lactose intolerance as well. -they are also useful as an alternative to milk-based formulas for vegan families. -despite these limited uses, soy formulas account for one-fourth of the infant formulas sold today. -while soy formulas support the normal growth and development of infants, for infants who don t need them, they offer no advantage over milk formulas. -inappropriate formulas caregivers must use only products designed for in- fants; soy beverages, for example, are nutritionally incomplete and inappropriate for infants. -goat s milk is also inappropriate for infants in part because of its low folate content. -an infant receiving goat s milk is likely to develop goat s milk anemia, an anemia characteristic of folate deficiency. -nursing bottle tooth decay an infant cannot be allowed to sleep with a bottle because of the potential damage to developing teeth. -salivary flow, which normally cleanses the mouth, diminishes as the infant falls asleep. -prolonged sucking on a bottle of formula, milk, or juice bathes the upper teeth in a carbohydrate-rich fluid that nourishes decay-producing bacteria. -(the tongue covers and protects most of the lower teeth, but they, too, may be affected.) -the result is extensive and rapid tooth decay (see figure 16-5, p. 554). -to prevent nursing bottle tooth decay, no infant should be put to bed with a bottle of nourishing fluid. -figure 16-4 percentages of energy- yielding nutrients in breast milk and in infant formula the average proportions of energy-yield- ing nutrients in human breast milk and formula differ slightly. -in contrast, cow s milk provides too much protein (20%) and too little carbohydrate (30%). -6% 55% 39% protein fat 9% 49% carbohydrate 42% breast milk infant formula s i b r o c / h s r e g n i e f n o j the infant thrives on infant formula offered with affection. -hypoallergenic formulas: clinically tested infant formulas that support infant growth and development but do not provoke reactions in 90% of infants or children with confirmed cow s milk allergy. -nursing bottle tooth decay: extensive tooth decay due to prolonged tooth contact with formula, milk, fruit juice, or other carbohydrate-rich liquid offered to an infant in a bottle. -554 chapter 16 figure 16-5 nursing bottle tooth decay this child was frequently put to bed sucking on a bottle filled with apple juice, so the teeth were bathed in carbo- hydrate for long periods of time a per- fect medium for bacterial growth. -the upper teeth show signs of decay. -o t o h p k c o t s l a c i d e m m o t s u c / l l i g . -h . -e special needs of preterm infants an estimated one out of eight pregnancies in the united states results in a preterm birth.27 the terms preterm and premature imply incomplete fetal development, or im- maturity, of many body systems. -as might be expected, preterm birth is a leading cause of infant deaths. -preterm infants face physical independence from their moth- ers before some of their organs and body tissues are ready. -the rate of weight gain in the fetus is greater during the last trimester of gestation than at any other time. -therefore, a preterm infant is most often a low-birthweight infant as well. -a prema- ture birth deprives the infant of the nutritional support of the placenta during a time of maximal growth. -the last trimester of gestation is also a time of building nutrient stores. -being born with limited nutrient stores intensifies the already precarious situation for the infant. -the physical and metabolic immaturity of preterm infants further compro- mises their nutrition status. -nutrient absorption, especially of fat and calcium, from an immature gi tract is limited. -consequently, preterm, low-birthweight in- fants are candidates for nutrient imbalances. -deficiencies of the fat-soluble vita- mins, calcium, iron, and zinc are common. -preterm breast milk is well suited to meet a preterm infant s needs. -during early lactation, preterm milk contains higher concentrations of protein and is lower in volume than term milk. -the low milk volume is advantageous because preterm in- fants consume small quantities of milk per feeding, and the higher protein concen- tration allows for better growth. -in many instances, supplements of nutrients specifically designed for preterm infants are added to the mother s expressed breast milk and fed to the infant from a bottle. -when fortified with a preterm supplement, preterm breast milk supports growth at a rate that approximates the growth rate that would have occurred within the uterus. -introducing cow s milk the age at which whole cow s milk should be introduced to the infant s diet has long been a source of controversy. -the aap advises that whole cow s milk is not appropri- ate during the first year.28 children one to two years of age should not be given re- duced-fat, low-fat, or fat-free milk routinely; they need the fat of whole milk. -between the ages of two and five years, a gradual transition from whole milk to the lower-fat milks can take place, but care should be taken to avoid excessive restric- tion of dietary fat. -dietary guidelines for americans 2005 children two to eight years should consume 2 cups per day of fat-free or low-fat milk or equivalent milk products. -in some infants, particularly those younger than six months of age, whole cow s milk may cause intestinal bleeding, which can lead to iron deficiency. -cow s milk is also a poor source of iron. -consequently, it both causes iron loss and fails to replace iron. -furthermore, the bioavailability of iron from infant cereal and other foods is reduced when cow s milk replaces breast milk or iron-fortified formula during the first year. -compared with breast milk or iron-fortified formula, cow s milk is higher in calcium and lower in vitamin c, characteristics that reduce iron absorption. -fur- thermore, the higher protein concentration of cow s milk can stress the infant s kid- neys. -in short, cow s milk is a poor choice during the first year of life; infants need breast milk or iron-fortified infant formula. -life cycle nutrition: infancy, childhood, and adolescence 555 introducing solid foods the high nutrient needs of infancy are met first by breast milk or formula only and then by the limited addition of selected foods over time. -infants gradually develop the ability to chew, swallow, and digest the wide variety of foods available to adults. -the caregiver s selection of appropriate foods at the appropriate stages of develop- ment is prerequisite to the infant s optimal growth and health. -when to begin in addition to breast milk or formula, an infant can begin eating solid foods between four and six months.29 the aap supports exclusive breastfeed- ing for six months but recognizes that infants are often developmentally ready to accept complementary foods between four and six months of age.30 the main pur- pose of introducing solid foods is to provide needed nutrients that are no longer sup- plied adequately by breast milk or formula alone. -the foods chosen must be those that the infant is developmentally capable of handling both physically and meta- bolically. -the exact timing depends on the individual infant s needs and develop- mental readiness (see table 16-3), which vary from infant to infant because of differences in growth rates, activities, and environmental conditions. -in short, the addition of foods to an infant s diet should be governed by three considerations: the infant s nutrient needs, the infant s physical readiness to handle different forms of foods, and the need to detect and control allergic reactions. -food allergies to prevent allergy and to facilitate its prompt identification should it occur, experts recommend introducing single-ingredient foods, one at a time, in small portions, and waiting four to five days before introducing the next new food.31 for example, rice cereal is usually the first cereal introduced because it the german word beikost (bye-cost) describes any nonmilk foods given to an infant. -digestive secretions gradually increase throughout the first year of life, making the digestion of solid foods more efficient. -table 16-3 infant development and recommended foods because each stage of development builds on the previous stage, the foods from an earlier stage continue to be included in all later stages. -age (mo) 0 4 4 6 6 8 8 10 feeding skill turns head toward any object that brushes cheek. -initially swallows using back of tongue; gradually begins to swallow using front of tongue as well. -strong reflex (extrusion) to push food out during first 2 to 3 months. -extrusion reflex diminishes, and the ability to swallow nonliquid foods develops. -indicates desire for food by opening mouth and leaning forward. -indicates satiety or disinterest by turning away and leaning back. -sits erect with support at 6 months. -begins chewing action. -brings hand to mouth. -grasps objects with palm of hand. -able to self-feed finger foods. -develops pincer (finger to thumb) grasp. -begins to drink from cup. -begins to hold own bottle. -reaches for and grabs food and spoon. -sits unsupported. -10 12 begins to master spoon, but still spills some. -appropriate foods added to the diet feed breast milk or infant formula. -begin iron-fortified cereal mixed with breast milk, formula, or water. -begin pureed vegetables and fruits. -begin textured vegetables and fruits. -begin unsweetened, diluted fruit juices from cup. -begin breads and cereals from table. -begin yogurt. -begin pieces of soft, cooked vegetables and fruit from table. -gradually begin finely cut meats, fish, casseroles, cheese, eggs, and mashed legumes. -add variety. -gradually increase portion sizes.a aportion sizes for infants and young children are smaller than those for an adult. -for example, a grain serving might be 1 2 slice of bread instead of 1 slice, or 1 4 cup rice instead of 1 2 cup. -source: adapted in part from committee on nutrition, american academy of pediatrics, pediatric nutrition handbook, 5th ed., ed. -r. e. kleinman (elk grove village, ill.: american academy of pediatrics, 2004), pp. -103 115). -556 chapter 16 foods such as iron-fortified cereals and formu- las, mashed legumes, and strained meats pro- vide iron. -is the least allergenic. -when it is clear that rice cereal is not causing an allergy, an- other grain, perhaps barley or oats, is introduced. -wheat cereal is offered last be- cause it is the most common offender. -if a cereal causes an allergic reaction such as a skin rash, digestive upset, or respiratory discomfort, it should be discontinued be- fore introducing the next food. -a later section in this chapter offers more informa- tion about food allergies. -choice of infant foods infant foods should be selected to provide variety, bal- ance, and moderation. -commercial baby foods offer a wide variety of palatable, nutritious foods in a safe and convenient form. -homemade infant foods can be as nutritious as commercially prepared ones, as long as the cook minimizes nutrient losses during preparation. -ingredients for homemade foods should be fresh, whole foods without added salt, sugar, or seasonings. -pureed food can be frozen in ice cube trays, providing convenient-sized blocks of food that can be thawed, warmed, and fed to the infant. -to guard against foodborne illnesses, hands and equipment must be kept clean. -. -c n i s o i d u t s a r a l o p because recommendations to restrict fat do not apply to children under age two, labels on foods for children under two (such as infant meats and cereals) cannot carry information about fat. -fat information is omitted from infant food labels to prevent parents from restricting fat in infants diets. -fearing that their infant will become overweight, parents may unintentionally malnourish the infant by limit- ing fat. -in fact, infants and young children, because of their rapid growth, need more fat than older children and adults. -foods to provide iron rapid growth demands iron. -at about four to six months, the infant begins to need more iron than body stores plus breast milk or iron- fortified formula can provide. -in addition to breast milk or iron-fortified formula, infants can receive iron from iron-fortified cereals and, once they readily accept solid foods, from meat or meat alternates such as legumes. -iron-fortified cereals contribute a significant amount of iron to an infant s diet, but the iron s bioavail- ability is poor.32 caregivers can enhance iron absorption from iron-fortified cereals by serving vitamin c rich foods with meals. -foods to provide vitamin c the best sources of vitamin c are fruits and vegeta- bles (see pp. -354 355 in chapter 10). -it has been suggested that infants who are in- troduced to fruits before vegetables may develop a preference for sweets and find the vegetables less palatable, but there is no evidence to support offering these foods in a particular order.33 fruit juice is a good source of vitamin c, but drinking too much juice can lead to diarrhea in infants and young children.34 aap recommendations limit juice con- sumption for infants and young children (one to six years of age) to between 4 and 6 ounces per day.35 beyond these limits, fruit juices contribute excessive kcalories and displace other nutrient-rich foods. -fruit juices should be diluted and served in a cup, not a bottle, once the infant is six months of age or older. -foods to omit concentrated sweets, including baby food desserts, have no place in an infant s diet. -they convey no nutrients to support growth, and the ex- tra food energy can promote obesity. -products containing sugar alcohols such as sorbitol should also be limited, as they may cause diarrhea. -canned vegetables are also inappropriate for infants, as they often contain too much sodium. -honey and corn syrup should never be fed to infants because of the risk of botulism. -* infants and young children are vulnerable to foodborne illnesses, and the dietary guide- lines 2005 address this risk. -botulism (bot-chew-lism): an often fatal foodborne illness caused by the ingestion of foods containing a toxin produced by bacteria that grow without oxygen. -(see chapter 19 for details.) -* in infants, but not in older individuals, ingestion of clostridium botulinum spores can cause illness when the spores germinate in the intestine and produce a toxin, which is absorbed. -symptoms include poor feeding, constipation, loss of tension in the arteries and muscles, weakness, and respiratory com- promise. -infant botulism has been implicated in 5 percent of cases of sudden infant death syndrome (sids). -life cycle nutrition: infancy, childhood, and adolescence 557 dietary guidelines for americans 2005 infants and young children should not eat or drink unpasteurized milk, milk products, or juices; raw or undercooked eggs, meat, poultry, fish, or shellfish; or raw sprouts. -infants and even young children cannot safely chew and swallow any of the foods listed in the margin; they can easily choke on these foods, a risk not worth taking. -nonfood items may present even greater choking hazards to infants and young children.36 parents and caregivers must pay careful attention to eliminate choking hazards in children s environments. -vegetarian diets during infancy the newborn infant is a lactovegetarian. -as long as the infant has access to sufficient quantities of either infant formula or breast milk (plus a vitamin d supplement) from a mother who eats an adequate diet, the infant will thrive during the early months. -health-food beverages, such as rice milk, are inappropriate choices because they lack the protein, vitamins, and minerals infants and toddlers need; in fact, their use can lead to severe nutritional deficiencies. -infants beyond about six months of age present a greater challenge in terms of meeting nutrient needs by way of vegetarian and, especially, vegan diets. -contin- ued breastfeeding or formula feeding is recommended, but supplementary feedings are necessary to ensure adequate energy and iron intakes. -infants and young chil- dren in vegetarian families should be given iron-fortified infant cereals well into the second year. -mashed or pureed legumes, tofu, and cooked eggs can be added to their diets in place of meat. -the risks of malnutrition in infants increase with weaning and reliance on table foods. -infants who receive a well-balanced vegetarian diet that includes milk prod- ucts and a variety of other foods can easily meet their nutritional requirements for growth. -this is not always true for vegan infants; the growth of vegan infants slows significantly around the time of transition from breast milk to solid foods. -protein- energy malnutrition and deficiencies of vitamin d, vitamin b12, iron, and calcium have been reported in infants fed vegan diets. -vegan diets that are high in fiber, other complex carbohydrates, and water will fill infants stomachs before meeting their energy needs. -this problem can be partially alleviated by providing more en- ergy-dense foods, such as nut butters, legumes, dried fruit spreads, and mashed av- ocado. -using soy formulas (or milk) fortified with calcium, vitamin b12, and vitamin d and including vitamin c containing foods at meals to enhance iron ab- sorption will help prevent other nutrient deficiencies in vegan diets. -parents or care- givers who choose to feed their infants vegan diets should consult with their pediatrician and a registered dietitian frequently to ensure a nutritionally ade- quate diet that will support growth. -foods at one year at one year of age, whole cow s milk can become a primary source of most of the nutrients an infant needs; 2 to 3 cups a day meets those needs sufficiently. -ingesting more milk than this can displace iron-rich foods, which can lead to milk anemia. -if powdered milk is used, it should contain fat. -other foods meats, iron-fortified cereals, enriched or whole-grain breads, fruits, and vegetables should be supplied in variety and in amounts sufficient to round out total energy needs. -ideally, a one-year-old will sit at the table, eat many of the same foods everyone else eats, and drink liquids from a cup, not a bottle. -fig- ure 16-6 shows a meal plan that meets a one-year-old s requirements. -mealtimes with toddlers the nurturing of a young child involves more than nutrition. -those who care for young children are responsible not only for providing nutritious milk, foods, and water, but also a safe, loving, secure environment in which the children may grow y r e g a m i k c o t s x e d n i / s n o i t c u d o r p w s ideally, a one-year-old eats many of the same foods as the rest of the family. -to prevent choking, do not give infants or young children: raw carrots cherries gum hard or gel-type candies nuts peanut butter popcorn raw celery whole beans whole grapes hot dog slices marshmallows keep these nonfood items out of their reach: coins small balls balloons pen tops figure 16-6 sample meal plan for a one-year-old s a m p l e m e n u breakfast 1 2 c iron-fortified, unsweetened breakfast cereal morning snack lunch afternoon snack 1 4 c whole milk (with cereal) 1 2 c orange juice 1 2 c yogurt 1 2 c fruita 1 2 sandwich: 1 slice bread with 2 tbs tuna salad or egg salad 1 2 c vegetablesb (steamed carrots) 1 2 c whole milk 1 2 slice whole-wheat toast 1 tbs apple butter 1 2 c whole milk dinner 1 oz chopped meat or 1 4 c well- cooked mashed legumes 1 4 c potato, rice, or pasta 1 2 c vegetablesb (chopped broccoli) 1 2 c whole milk ainclude citrus fruits, melons, and berries. -binclude dark green, leafy and deep yellow vegetables. -milk anemia: iron-deficiency anemia that develops when an excessive milk intake displaces iron-rich foods from the diet. -558 chapter 16 and develop. -in light of toddlers developmental and nutrient needs and their often contrary and willful behavior, a few feeding guidelines may be helpful: discourage unacceptable behavior, such as standing at the table or throwing food, by removing the young child from the table to wait until later to eat. -be consistent and firm, not punitive. -the child will soon learn to sit and eat. -let toddlers explore and enjoy food, even if this means eating with fingers for a while. -learning to use a spoon will come in time. -don t force food on children. -rejecting new foods is normal and acceptance is more likely as children become familiar with new foods through repeated opportunities to taste them. -provide nutritious foods, and let children choose which ones, and how much, they will eat. -gradually, they will acquire a taste for different foods. -limit sweets. -infants and young children have little room for empty-kcalorie foods in their daily energy allowance. -do not use sweets as a reward for eat- ing meals. -don t turn the dining table into a battleground. -make mealtimes enjoyable. -teach healthy food choices and eating habits in a pleasant environment. -s i b r o c toddlers need vitamin a and vitamin d fortified whole milk. -in summary the primary food for infants during the first 12 months is either breast milk or iron-fortified formula. -in addition to nutrients, breast milk also offers im- munological protection. -at about four to six months, infants should gradually begin eating solid foods. -by one year, they are drinking from a cup and eating many of the same foods as the rest of the family. -nutrition during childhood each year from age one to adolescence, a child typically grows taller by 2 to 3 inches and heavier by 5 to 6 pounds. -growth charts provide valuable clues to a child s health. -weight gains out of proportion to height gains may reflect overeating and inactivity, whereas measures significantly below the standard suggest malnutrition. -increases in height and weight are only two of the many changes growing children experience (see figure 16-7). -at age one, children can stand alone and are beginning to toddle; by two, they can walk and are learning to run; and by three, they can jump and climb with confidence. -bones and muscles increase in mass and density to make these accomplishments possible. -thereafter, lengthening of the long bones and in- creases in musculature proceed unevenly and more slowly until adolescence. -energy and nutrient needs children s appetites begin to diminish around one year, consistent with the slowing growth. -thereafter, children spontaneously vary their food intakes to coincide with their growth patterns; they demand more food during periods of rapid growth than during slow growth. -sometimes they seem insatiable, and other times they seem to live on air and water. -children s energy intakes also vary widely from meal to meal. -even so, their to- tal daily intakes remain remarkably constant.37 if children eat less at one meal, they typically eat more at the next, and vice versa. -overweight children are excep- tions: they do not always adjust their energy intakes appropriately and may eat in response to external cues, disregarding hunger and satiety signals. -energy intake and activity individual children s energy needs vary widely, depend- ing on their growth and physical activity. -a one-year-old child needs about 800 kcalo- figure 16-7 body shape of one-year-old and two-year-old compared life cycle nutrition: infancy, childhood, and adolescence 559 ) h t o b ( i l l e n n a v . -m y n o h t n a the body shape of a one-year-old (left) changes dramatically by age two (right). -the two-year-old has lost much of the baby fat; the muscles (especially in the back, buttocks, and legs) have firmed and strengthened; and the leg bones have lengthened. -ries a day; an active six-year-old needs twice as many kcalories a day. -by age ten, an active child needs about 2000 kcalories a day. -total energy needs increase slightly with age, but energy needs per kilogram of body weight actually decline gradually. -physically active children of any age need more energy because they expend more, and inactive children can become obese even when they eat less food than the average. -unfortunately, our nation s children are becoming less and less active, with young girls showing a marked reduction in their physical activity. -schools would serve our children well by offering activities to promote physical fitness.38 children who learn to enjoy physical play and exercise, both at home and at school, are best prepared to maintain active lifestyles as adults. -dietary guidelines for americans 2005 children should engage in at least 60 minutes of physical activity on most, preferably all, days of the week. -some children, notably those adhering to a vegan diet, may have difficulty meeting their energy needs. -grains, vegetables, and fruits provide plenty of fiber, adding bulk, but may provide too few kcalories to support growth. -soy products, other legumes, and nut or seed butters offer more concentrated sources of energy to support optimal growth and development.39 carbohydrate and fiber carbohydrate recommendations are based on glucose use by the brain. -after one year of age, brain glucose use remains fairly constant and is within the adult range. -carbohydrate recommendations for children from the age of one year on are therefore the same as for adults (see inside front cover).40 fiber recommendations derive from adult intakes shown to reduce the risk of coronary heart disease and are based on energy intakes. -consequently, fiber rec- ommendations for younger children with low energy intakes are less than those for older ones with high energy intakes.41 dietary guidelines for americans 2005 children and adolescents should consume whole-grain products often, and at least half of the grains should be whole grains. -fiber recommendations for children: age (yr) 1 3 4 8 9 13 boys girls 14 18 boys girls ai (g/day) 19 25 31 26 38 26 560 chapter 16 www.mypyramid.gov/kids fat and fatty acids no rda for total fat has been established, but the dri com- mittee recommends a fat intake of 30 to 40 percent of energy for children 1 to 3 years of age and 25 to 35 percent for children 4 to 18 years of age.42 as long as children s energy intakes are adequate, fat intakes below 30 percent of total energy do not im- pair growth.43 children who eat low-fat diets, however, tend to have low intakes of some vitamins and minerals. -recommended intakes of the essential fatty acids are based on average intakes (see inside front cover). -dietary guidelines for americans 2005 keep total fat intake between 30 to 35 percent of kcalories for children 2 to 3 years of age and between 25 and 35 percent of kcalories for children and adolescents 4 to 18 years of age, with most fats coming from sources of polyunsaturated and monounsaturated fatty acids, such as fish, nuts, and vegetable oils. -protein like energy needs, total protein needs increase slightly with age, but when the child s body weight is considered, the protein requirement actually declines slightly (see inside front cover). -protein recommendations must consider the require- ments for maintaining nitrogen balance, the quality of protein consumed, and the added needs of growth. -vitamins and minerals the vitamin and mineral needs of children increase with age (see inside front cover). -a balanced diet of nutritious foods can meet chil- dren s needs for these nutrients, with the notable exception of iron. -iron-deficiency anemia is a major problem worldwide, as well as being prevalent among u.s. and canadian children, especially toddlers one to two years of age.44 during the second year of life, toddlers progress from a diet of iron-rich infant foods such as breast milk, iron-fortified formula, and iron-fortified infant cereal to a diet of adult foods and iron-poor cow s milk. -in addition, their appetites often fluctuate some become finicky about the foods they eat, and others prefer milk and juice to solid foods.45 all of these situations can interfere with children eating iron-rich foods at a critical time for brain growth and development. -to prevent iron deficiency, children s foods must deliver 7 to 10 milligrams of iron per day. -to achieve this goal, snacks and meals should include iron-rich foods, and milk intake should be reasonable so that it will not displace lean meats, fish, poultry, eggs, legumes, and whole-grain or enriched products. -(chapter 13 de- scribed iron-rich foods and ways to maximize iron absorption.) -supplements with the exception of specific recommendations for fluoride, iron, and vitamin d during infancy and childhood, the aap and other professional groups agree that well-nourished children do not need vitamin and mineral supple- ments. -despite this, many children and adolescents take supplements.46 ironically, children with poor nutrient intakes typically do not receive supplements, and those who do take supplements typically receive extra nutrients they do not need.47 fur- thermore, researchers are still studying the safety of supplement use by children.48 the federal trade commission has warned parents about giving supplements ad- vertised to prevent or cure childhood illnesses such as colds, ear infections, or asthma. -dietary supplements on the market today include many herbal products that have not been tested for safety and effectiveness in children. -planning children s meals to provide all the needed nutrients, children s meals should include a variety of foods from each food group in amounts suited to their appetites and needs. -figure 16-8 presents mypyramid designed for children 6 to 11 years of age and includes the recommended amounts of food for an 1800-kcalorie intake. -table 16-4 (p. 562) lists amounts of food for several kcalorie levels below 1800 kcalories, which are appropriate for most younger children and sedentary older chil- dren. -review table 2-3 on page 41 for recommended daily amounts of foods from each group for higher kcalorie levels, which are appropriate for active older children. -figure 16-8 food guide pyramid for young children life cycle nutrition: infancy, childhood, and adolescence 561 estimated daily kcalorie needs for active and sedentary children of various ages are shown in table 16-5 (p. 562). -children whose diets follow the pattern presented in figure 16-8 meet their nu- trient needs fully, but few children eat according to these recommendations. -based on an analysis of the most recent national food intake data, the usda found that most (81 percent) children between two and nine years of age have diets that need substantial improvement.49 a comprehensive survey, called the feeding infants and toddlers study (fits), assessed the food and nutrient intakes of more than 3000 infants and toddlers.50 the survey found that fruit and vegetable intakes of infants and toddlers are limited, and in fact, about 25 percent of infants and toddlers older than 9 months did not eat a single serving of fruits or vegetables in a day.51 by 15 562 chapter 16 table 16-5 needs for children estimated daily kcalorie children sedentarya activeb 2 to 3 yr females 4 to 8 yr 9 to 13 yr males 4 to 8 yr 9 to 13 yr 1000 1400 1200 1600 1400 1800 1800 2200 2000 2600 a sendentary describes a lifestyle that includes only the activities typical of day-to-day life. -b active describes a lifestyle that includes at least 60 minutes per day of moderate physical activity (equivalent to walking more than 3 miles per day at 3 to 4 miles per hour) in addition to the activities of day-to-day life. -table 16-4 (1000 to 1600 kcalories) recommended daily amounts from each food group food group 1000 kcal 1200 kcal 1400 kcal 1600 kcal fruits vegetables grains meat and legumes milk oils 1 c 1 c 3 oz 2 oz 2 c 3 tsp 1 c 11 2 c 4 oz 3 oz 2 c 3 tsp 11 2 c 11 2 c 5 oz 4 oz 2 c 3 tsp 11 2 c 2 c 5 oz 5 oz 3 c 4 tsp note: the discretionary kcalorie allowance for these patterns is about 100 kcalories. -to 18 months of age, the most commonly consumed vegetable was french fries and the most commonly consumed fruit was bananas neither particularly rich sources of vitamins or minerals. -parents and caregivers of infants and toddlers thus need to offer a much greater variety of nutrient-dense vegetables and fruits at meals and snacks to help ensure adequate nutrition. -among other nutrition con- cerns for u.s. children are inadequate intakes of calcium and fiber and excessive in- takes of saturated fat.52 hunger and malnutrition in children most children in the united states and canada have access to regular meals, but hunger and malnutrition do appear in certain circumstances. -children in very low- income families, for example, are more likely to be hungry and malnourished. -an estimated 12 million u.s. children are hungry at least some of the time and are liv- ing in poverty.53 chapter 20 examines the causes and consequences of hunger in the united states and around the world. -when hunger is chronic, children become malnourished and suffer growth re- tardation. -worldwide, malnutrition takes a devastating toll on children, contribut- ing to nearly half of the deaths of children under four years old. -vitamin a deficiency afflicts 3 to 10 million children worldwide, inducing blindness, stunted growth, and infections.54 zinc deficiency also retards growth and typically accom- panies protein-energy malnutrition and vitamin a deficiency. -the united nations children s fund, known as unicef, helps children living in poverty in developing countries get the nutrition and health care they need. -unicef works with more than 160 countries through national governments, pri- vate-sector partners, and other international agencies to protect children and their rights and to reduce childhood death and illness. -hunger and behavior even when hunger is temporary, as when a child misses one meal, behavior and academic performance are affected. -children who eat nu- tritious breakfasts improve their school performance and are tardy or absent signif- icantly less often than their peers who do not. -a nutritious breakfast is a central feature of a diet that meets the needs of children and supports their healthy growth and development.55 children who skip breakfast typically do not make up the deficits at later meals they simply have lower intakes of energy, vitamins, and minerals than those who eat breakfast. -without breakfast, children perform poorly in tasks requiring concentration, their attention spans are shorter, and they even score lower on intelligence tests than their well-fed peers. -malnourished children are particularly vulnerable. -common sense dictates that it is unreasonable to expect anyone to learn and perform without fuel. -for the child who hasn t had breakfast, the morning s lessons may be lost altogether. -even if a child has eaten breakfast, dis- comfort from hunger may become distracting by late morning. -teachers aware of the late-morning slump in their classrooms wisely request that midmorning snacks be provided; snacks improve classroom performance all the way to lunchtime. -life cycle nutrition: infancy, childhood, and adolescence 563 iron deficiency and behavior iron deficiency has well-known and widespread effects on children s behavior and intellectual performance.56 in addition to carrying oxygen in the blood, iron transports oxygen within cells, which use it for energy metabolism. -iron is also used to make neurotransmitters most notably, those that regulate the abil- ity to pay attention, which is crucial to learning. -consequently, iron deficiency not only causes an energy crisis, but also directly impairs attention span and learning ability. -iron deficiency is often diagnosed by a quick, easy, inexpensive hemoglobin or hematocrit test that detects a deficit of iron in the blood. -a child s brain, however, is sensitive to low iron concentrations long before the blood effects appear. -iron defi- ciency lowers the motivation to persist in intellectually challenging tasks and im- pairs overall intellectual performance. -anemic children perform poorly on tests and are disruptive in the classroom; iron supplementation improves learning and memory. -when combined with other nutrient deficiencies, iron-deficiency anemia has synergistic effects that are especially detrimental to learning. -furthermore, children who had iron-deficiency anemia as infants continue to perform poorly as they grow older, even if their iron status improves.57 the long-term damaging ef- fects on mental development make prevention and treatment of iron deficiency during infancy and early childhood a high priority. -s e g a m i y t t e g / e l y o d e g r o e g other nutrient deficiencies and behavior a child with any of several nutri- ent deficiencies may be irritable, aggressive, and disagreeable, or sad and with- drawn. -such a child may be labeled hyperactive, depressed, or unlikable, when in fact these traits may be due to simple, even marginal, malnutrition. -parents and medical practitioners often overlook the possibility that malnutrition may ac- count for abnormalities of appearance and behavior. -any departure from normal healthy appearance and behavior is a sign of possible poor nutrition (see table 16- 6). -in any such case, inspection of the child s diet by a registered dietitian or other qualified health care professional is in order. -any suspicion of dietary inadequacies, no matter what other causes may be implicated, should prompt steps to correct those inadequacies immediately. -healthy, well-nourished children are alert in the classroom and energetic at play. -table 16-6 physical signs of malnutrition in children hair eyes well-nourished malnourished possible nutrient deficiencies shiny, firm in the scalp dull, brittle, dry, loose; falls out pem bright, clear pink membranes; adjust easily to light pale membranes; spots; redness; adjust slowly to darkness vitamin a, the b vitamins, zinc, and iron teeth and gums no pain or caries, gums firm, teeth bright missing, discolored, decayed teeth; gums bleed easily and are swollen and spongy minerals and vitamin c face glands tongue skin clear complexion without dryness or scaliness off-color, scaly, flaky, cracked skin pem, vitamin a, and iron no lumps swollen at front of neck, cheeks pem and iodine red, bumpy, rough sore, smooth, purplish, swollen b vitamins smooth, firm, good color dry, rough, spotty; sandpaper feel or sores; lack of fat under skin pem, essential fatty acids, vitamin a, b vitamins, and vitamin c nails firm, pink spoon-shaped, brittle, ridged iron internal systems regular heart rhythm, heart rate, and blood pressure; no impairment of diges- tive function, reflexes, or mental status muscles and bones muscle tone; posture, long bone development appropriate for age abnormal heart rate, heart rhythm, or blood pressure; enlarged liver, spleen; abnormal digestion; burning, tingling of hands, feet; loss of balance, coordination; mental confusion, irritability, fatigue wasted appearance of muscles; swollen bumps on skull or ends of bones; small bumps on ribs; bowed legs or knock- knees pem and minerals pem, minerals, and vitamin d 564 chapter 16 old, lead-based paint threatens the health of an exploring child. -hyperactivity: inattentive and impulsive behavior that is more frequent and severe than is typical of others a similar age; professionally called attention- deficit/hyperactivity disorder (adhd). -t i d e o t o h p / n a m e e r f y n o t the malnutrition-lead connection children who are malnourished are vulnerable to lead poisoning. -they absorb more lead if their stomachs are empty; if they have low intakes of calcium, zinc, vitamin c, or vitamin d; and, of greatest concern because it is so common, if they have iron defi- ciencies. -iron deficiency weakens the body s defenses against lead absorption, and lead poisoning can cause iron deficiency. -common to both iron deficiency and lead poison- ing are a low socioeconomic background and a lack of immunizations against infec- tious diseases. -another common factor is pica a craving for nonfood items. -many children with lead poisoning eat dirt or chips of old paint, two common sources of lead. -the anemia brought on by lead poisoning may be mistaken for a simple iron deficiency and therefore may be incorrectly treated. -like iron deficiency, mild lead toxicity has nonspecific symptoms, including diarrhea, irritability, and fatigue. -adding iron to the diet does not reverse the symptoms; exposure to lead must stop and treatment for lead poisoning must begin. -with further exposure, the symp- toms become more pronounced, and children develop learning disabilities and be- havioral problems. -still more severe lead toxicity can cause irreversible nerve damage, paralysis, mental retardation, and death. -more than 300,000 children in the united states most of them under age six have blood lead concentrations high enough to cause mental, behavioral, and other health problems.58 lead toxicity in young children comes from their own be- haviors and activities putting their hands in their mouths, playing in dirt and dust, and chewing on nonfood items.59 unfortunately, the body readily absorbs lead during times of rapid growth and hoards it possessively thereafter. -lead is not easily excreted and accumulates mainly in the bones, but also in the brain, teeth, and kidneys. -tragically, a child s neuromuscular system is also maturing during these first few years of life. -no wonder children with elevated lead levels experience impairment of balance, motor development, and the relaying of nerve messages to and from the brain. -deficits in intellectual development are only partially reversed when lead levels decline.60 federal laws mandating reductions in leaded gasolines, lead-based solder, and other products over the past four decades have helped to reduce the amounts of lead in food and in the environment in the united states. -as a consequence, the preva- lence of lead toxicity in children has declined dramatically for most of the united states, but lead exposure is still a threat in certain communities.61 the accompany- ing how to presents strategies for defending children against lead toxicity. -hyperactivity and hyper behavior all children are naturally active, and many of them become overly active on occa- sion for example, in anticipation of a birthday party. -such behavior is markedly different from true hyperactivity. -hyperactivity hyperactive children have trouble sleeping, cannot sit still for more than a few minutes at a time, act impulsively, and have difficulty paying at- tention. -these behaviors interfere with social development and academic progress. -the cause of hyperactivity remains unknown, but it affects about 5 to 10 percent of young school-age children.62 to resolve the problems surrounding hyperactivity, physicians often recommend specific behavioral strategies, special educational pro- grams, and psychological counseling. -in many cases, they prescribe medication.63 parents of hyperactive children sometimes seek help from alternative therapies, including special diets. -they mistakenly believe a solution may lie in manipulat- ing the diet most commonly, by excluding sugar or food additives. -adding carrots or eliminating candy is such a simple solution that many parents eagerly give such dietary advice a try. -however, these dietary changes will not solve the problem, and studies have consistently found no convincing evidence that sugar causes hyperac- tivity or worsens behavior. -how to protect against lead toxicity researchers simultaneously made three major discoveries about lead toxicity: lead poisoning has subtle effects, the effects are permanent, and they occur at low levels of exposure. -the amount of lead recognized to cause harm is only 10 micrograms per 100 milliliters of blood. -some research shows that blood lead concentrations below this amount may adversely affect children s scores on intelligence tests.a consequently, consumers should take ultraconservative measures to protect themselves, and espe- cially their infants and young children, from lead poisoning. -the american academy of pediatrics and the centers for disease con- trol recommend screening in communities with a substantial number of houses built before 1950 and in those with a substantial number of children with elevated lead levels. -in addition to screening children most likely to be exposed, pediatricians should alert all parents to the possible dangers of lead exposure and explain pre- vention strategies. -preventive strategies include: in contaminated environments, keep small children from putting dirty or old painted objects in their mouths, and make sure children wash their hands before eating. -similarly, keep small children from eating any nonfood items. -lead poisoning has ar. -l. canfield and coauthors, intellectual impairment in children with blood lead concentrations below 10 g per deciliter, new england journal of medicine 348 (2003): 1517 1526. life cycle nutrition: infancy, childhood, and adolescence 565 been reported in young children who have eaten crayons or pool cue chalk. -a wine bottle with a clean wet cloth before removing the cork. -wet-mop floors and damp-sponge walls regularly. -children s blood lead levels decline when the homes they live in are cleaned regularly. -be aware that other countries do not have the same regulations protecting consumers against lead. -children have been poisoned by eating crayons made in china and drinking fruit juice canned in mexico. -do not use lead-contaminated water to make infant formula. -once you have opened canned food, store it in a lead-free container to prevent lead migration into the food. -do not store acidic foods or beverages (such as vinegar or orange juice) in ceramic dishware or alcoholic beverages in pewter or crystal decanters. -many manufacturers are now making lead- safe products. -old, handmade, or im- ported ceramic cups and bowls may contain lead and should not be used to heat coffee or tea or acidic foods such as tomato soup. -u.s. wineries have stopped using lead in their foil seals, but older bottles may still be around, and other countries may still use lead. -to be safe, wipe the foil-sealed rim of b call the national lead information center hotline at (800) 424-lead (424-5323) for general information. -feed children nutritious meals regularly. -before using your newspaper to wrap food, mulch garden plants, or add to your com- post, confirm with the publisher that the paper uses no lead in its ink. -the environmental protection agency (epa) also publishes a booklet, lead and your drinking water, in which the following cautions appear: have the water in your home tested by a competent laboratory. -use only cold water for drinking, cooking, and making formula (cold water absorbs less lead). -when water has been standing in pipes for more than two hours, flush the cold-water pipes by running water through them for 30 seconds before using it for drinking, cooking, or mixing formulas. -if lead contamination of your water supply seems probable, obtain additional informa- tion and advice from the epa and your local public health agency. -by taking these steps, parents can protect themselves and their children from this preventable danger.b misbehaving even a child who is not truly hyperactive can be difficult to manage at times. -michael may act unruly out of a desire for attention, jessica may be cranky because of a lack of sleep, christopher may react violently after watching too much television, and sheila may be unable to sit still in class due to a lack of exercise. -all of these children may benefit from more consistent care regular hours of sleep, reg- ular mealtimes, and regular outdoor activity. -food allergy and intolerance food allergy is frequently blamed for physical and behavioral abnormalities in children, but just 6 percent of children are diagnosed with true food allergies.64 food allergies diminish with age, until in adulthood they affect only about 1 or 2 percent of the population.65 a true food allergy occurs when fractions of a food protein or other large mole- cule are absorbed into the blood and elicit an immunologic response. -(recall that proteins are normally dismantled in the digestive tract to amino acids that are ab- sorbed without such a reaction.) -the body s immune system reacts to these large food molecules as it does to other antigens by producing antibodies, histamines, or other defensive agents. -a person who produces antibodies without having any symptoms has an asympto- matic allergy; a person who produces antibodies and has symptoms has a symp- tomatic allergy. -detecting food allergy allergies may have one or two components. -they al- ways involve antibodies, but they may or may not involve symptoms. -this means food allergy: an adverse reaction to food that involves an immune response; also called food-hypersensitivity reaction. -566 chapter 16 these normally wholesome foods may cause life-threatening symptoms in people with allergies. -symptoms of impending anaphylactic shock: tingling sensation in mouth swelling of the tongue and throat irritated, reddened eyes difficulty breathing, asthma hives, swelling, rashes vomiting, abdominal cramps, diarrhea drop in blood pressure loss of consciousness death reminder: epinephrine is a hormone of the adrenal gland that modulates the stress response; formerly called adrenaline. -when administered by injection, epineph- rine counteracts anaphylactic shock by opening the airways and maintaining heartbeat and blood pressure. -anaphylactic (ana- fill-lac-tic) shock: a life- threatening, whole-body allergic reaction to an offending substance. -adverse reactions: unusual responses to food (including intolerances and allergies). -food intolerances: adverse reactions to foods that do not involve the immune system. -that allergies can be diagnosed only by testing for antibodies. -even symptoms ex- actly like those of an allergy may not be caused by an allergy. -however, once a food allergy has been diagnosed, the required treatment is strict elimination of the of- fending food. -children with allergies, like all children, need all their nutrients, so it is important to include other foods that offer the same nutrients as the omitted foods.66 allergic reactions to food may be immediate or delayed. -in either case, the anti- gen interacts immediately with the immune system, but the timing of symptoms varies from minutes to 24 hours after consumption of the antigen. -identifying the food that causes an immediate allergic reaction is fairly easy because the symptoms appear shortly after the food is eaten. -identifying the food that causes a delayed re- action is more difficult because the symptoms may not appear until much later. -by this time, many other foods may have been eaten, complicating the picture. -. -c n i , s o i d u t s a r a l o p anaphylactic shock the life-threatening food allergy reaction of anaphylactic shock is most often caused by peanuts, tree nuts, milk, eggs, wheat, soybeans, fish, or shellfish. -among these foods, eggs, milk, soy, and peanuts most often cause prob- lems in children. -children are more likely to outgrow allergies to eggs, milk, and soy than allergies to peanuts. -peanuts cause more life-threatening reactions than do all other food allergies combined. -research is currently under way to help people with peanut allergies tolerate small doses, thus saving lives and minimizing reactions.67 one possible solution depends on finding a natural, hypoallergenic peanut among the 14,000 varieties of peanuts. -families of children with a life-threatening food al- lergy and school personnel who supervise them must guard them against any expo- sure to the allergen. -the child must learn to identify which foods pose a problem and then learn and use refusal skills for all foods that may contain the allergen. -parents of children with allergies can pack safe foods for lunches and snacks and ask school officials to strictly enforce a no swapping policy in the lunchroom. -the child must be able to recognize the symptoms of impending anaphylactic shock, such as a tingling of the tongue, throat, or skin, or difficulty breathing. -any person with food allergies severe enough to cause anaphylactic shock should wear a medical alert bracelet or necklace. -finally, the responsible child and the school staff should be prepared with injections of epinephrine, which prevents anaphylaxis after expo- sure to the allergen. -many preventable deaths occur each year when people with food allergies accidentally ingest the allergen but have no epinephrine available. -food labeling as of 2006, food labels must list the presence of common allergens in plain language, using the names of the eight most common allergy-causing foods.68 for example, a food containing textured vegetable protein must say soy on its label. -similarly, casein must be identified as milk, and so forth. -food pro- ducers must also prevent cross-contamination during production and clearly label foods in which it is likely to occur.69 for example, equipment used for making peanut butter must be scrupulously clean before being used to pulverize cashew nuts for cashew butter to protect unsuspecting cashew butter consumers from peanut allergens. -technology may soon offer new solutions. -new drugs are being developed that may interfere with the immune response that causes allergic reactions.70 also, through genetic engineering, scientists may one day create allergen-free peanuts, soybeans, and other foods to make them safer. -food intolerances not all adverse reactions to foods are food allergies, al- though even physicians may describe them as such. -signs of adverse reactions to foods include stomachaches, headaches, rapid pulse rate, nausea, wheezing, hives, bronchial irritation, coughs, and other such discomforts. -among the causes may be reactions to chemicals in foods, such as the flavor enhancer monosodium glutamate (msg), the natural laxative in prunes, or the mineral sulfur; digestive diseases, such as obstructions or injuries; enzyme deficiencies, such as lactose intolerance; and even psychological aversions. -these reactions involve symptoms but no antibody production. -therefore, they are food intolerances, not allergies. -life cycle nutrition: infancy, childhood, and adolescence 567 pesticides on produce may also cause adverse reactions. -pesticides that were ap- plied in the fields may linger on the foods. -health risks from pesticide exposure may be low for healthy adults, but children are vulnerable. -therefore, government agencies have set a tolerance level for each pesticide by first identifying foods that children commonly eat in large amounts and then considering the effects of pesticide exposure during each developmental stage. -chapter 19 revisits the issues surrounding the use of pesticides on food crops. -hunger, lead poisoning, hyperactivity, and allergic reactions can all adversely af- fect a child s nutrition status and health. -fortunately, each of these problems has solutions. -they may not be easy solutions, but at least we have a reasonably good understanding of the problems and ways to correct them. -such is not the case with the most pervasive health problem for children in the united states obesity. -childhood obesity the number of overweight children has increased dramatically over the past three decades (see figure 16-9). -like their parents, children in the united states are be- coming fatter. -an estimated 17 percent of u.s. children and adolescents 2 to 19 years of age are overweight.71 based on data from the bmi-for-age growth charts, children and adolescents are categorized as at risk of overweight above the 85th per- centile and as overweight at the 95th percentile and above. -prevalence data reflect only children and adolescents in the overweight category. -if those at risk of over- weight were also included, the estimated 17 percent would likely double. -figure 16- 10 (p. 568) presents the bmi for children and adolescents, indicating cutoff points for overweight and at risk of overweight. -the use of the term overweight instead of obese when referring to children with a bmi above the age- and gender-specific 95th percentiles is controversial. -some ex- perts think it is best not to label children as obese, whereas others think it impor- tant to recognize the full extent of the problem. -the institute of medicine s committee on prevention of obesity in children and youth acknowledges the use of the term overweight to describe obese children but asserts that obese conveys the seriousness, urgency, medical nature, and need for immediate action more effec- tively than the term overweight does.72 the problem of obesity in children is especially troubling because overweight children have the potential of becoming obese adults with all the social, economic, and medical ramifications that often accompany obesity. -they have additional problems, too, arising from differences in their growth, physical health, and psy- chological development. -in trying to explain the rise in childhood obesity, re- searchers point to both genetic and environmental factors. -genetic and environmental factors parental obesity predicts an early increase in a young child s bmi, and it more than doubles the chances that a young child will become an obese adult. -children with neither parent obese have a less than 10 per- cent chance of becoming obese in adulthood, whereas overweight teens with at least one obese parent have a greater than 80 percent chance of being obese adults. -also, as children grow older, their body weight becomes an important factor in determin- ing their obesity as adults.73 the link between parental and child obesity reflects both genetic and environmental factors (as described in chapter 9). -diet and physical inactivity must also play a role in explaining why children are heavier today than they were 30 or so years ago. -as the prevalence of childhood obesity throughout the united states has more than doubled for young children and adolescents, and tripled for children 6 to 11 years of age, the society our children live in has changed considerably.74 in many families today, both parents work outside the home and work longer hours; more emphasis is placed on convenience foods and foods eaten away from home; meal choices at school are more diverse and of- ten less nutritious; sedentary activities such as watching television and playing video or computer games occupy much of children s free time; and opportunities for figure 16-9 trends in childhood obesity key: age 6 11 years age 12 19 years t n e c r e p 20 15 10 5 0 1970s 1980s 1990s 2000s tolerance level: the maximum amount of residue permitted in a food when a pesticide is used according to the label directions. -568 chapter 16 figure 16-10 body mass index-for-age percentiles: boys and girls, age 2 to 20 36 34 32 30 28 26 24 22 20 18 16 14 12 ) 2 m g k ( / i m b body mass index-for-age percentiles: boys, 2 to 20 years body mass index-for-age percentiles: girls, 2 to 20 years 97th 95th 85th 50th 10th 3rd 97th 95th 85th 50th 10th 3rd 36 34 32 30 28 26 24 22 20 18 16 14 12 ) 2 m g k ( / i m b 2 4 6 8 10 12 14 16 18 20 2 4 6 8 10 12 14 16 18 20 age (years) key: age (years) overweight 95th percentile normal 10th to 85th percentile at risk of overweight >85th percentile underweight <10th percentile physical activity and outdoor play both during and after school have declined.75 all of these factors and many others influence children s eating and activity patterns. -children learn food behaviors from their families, and research confirms the sig- nificant roles parents play in teaching their children about healthy food choices, providing nutrient-dense foods, and serving as role models.76 when parents eat fruits and vegetables frequently, their children do, too.77 the more fruits and veg- etables children eat, the more vitamins, minerals, and fibers, and the less saturated fat in their diets. -research shows that one in four toddlers (19 to 24 months of age) exceeds esti- mated energy requirements as a result of eating such foods as candy, pizza, chicken nuggets, soda, sweet tea, and salty snacks like cheese puffs and chips.78 thus, when researchers ask, are today s children eating more kcalories than those of 30 years ago? -the answer is, yes. -some researchers report an increase of 100 to 200 kcalo- ries a day for all age groups, enough to account for significant weight gains.79 coincidentally or not, as the prevalence of obesity among both children and adults has surged over the past three decades, so has the consumption of added sugars and, especially, high-fructose corn syrup the easily consumed, energy- dense liquid sugar added to soft drinks. -each 12-ounce can of soft drink provides the equivalent of about 10 teaspoons of sugar and 150 kcalories. -more than half of children in school consume at least one soft drink each day at school; adolescent males consume the most four or more cans daily.80 according to one estimate, the risk of obesity increases by 60 percent with each sugared soft drink consumed daily.81 life cycle nutrition: infancy, childhood, and adolescence 569 no doubt, the tremendous increase in soft drink consumption plays a role, but much of the obesity epidemic can be explained by lack of physical activity. -chil- dren have become more sedentary, and sedentary children are more often over- weight.82 television watching may contribute most to physical inactivity. -a child who spends more than an hour or two each day in front of a television, computer monitor, or other media can become overweight and develop unhealthy blood lipids even while eating fewer kcalories than a more active child.83 children who have television sets in their bedrooms spend more time watching tv and are more likely to be overweight than children who do not have televisions in their rooms.84 children who watch a great deal of television are most likely to be overweight and least likely to eat family meals or fruits and vegetables.85 they of- ten snack on the nutrient-poor, energy-dense foods that are advertised.86 the aver- age child sees an estimated 30,000 tv commercials a year many peddling foods high in sugar, saturated fat, and salt such as sugar-coated breakfast cereals, candy bars, chips, fast foods, and carbonated beverages. -more than half of all food adver- tisements are aimed specifically at children and market their products as fun and exciting.87 not surprisingly, the more time children spend watching television, the more they request these advertised foods and beverages and they get their re- quests about half of the time.88 the most popular foods and beverages are mar- keted to children and adolescents on the internet as well, using advergaming (advertised product as part of a game), cartoon characters or spokes-characters, and designated children s areas.89 the physically inactive time spent watching television is second only to time spent sleeping. -children also spend more time playing video games. -these activities use no more energy than resting, displace participation in more vigorous activities, and foster snacking on high-fat foods.90 simply reducing the amount of time spent watching television (and playing video games) can improve a child s bmi. -the american academy of pediatrics (aap) now recommends limiting television and video time to two hours per day as a strategy to help prevent childhood obesity.91 growth overweight children develop a characteristic set of physical traits. -they typically begin puberty earlier and so grow taller than their peers at first, but then they stop growing at a shorter height. -they develop greater bone and muscle mass in response to the demand of having to carry more weight both fat and lean weight. -consequently, they appear stocky even when they lose their excess fat. -physical health like overweight adults, overweight children display a blood lipid profile indicating that atherosclerosis is beginning to develop high levels of total cholesterol, triglycerides, and ldl cholesterol. -overweight children also tend to have high blood pressure; in fact, obesity is a leading cause of pediatric hyperten- sion.92 their risks for developing type 2 diabetes and respiratory diseases (such as asthma) are also exceptionally high.93 these relationships between childhood obe- sity and chronic diseases are discussed fully in highlight 16. psychological development in addition to the physical consequences, child- hood obesity brings a host of emotional and social problems.94 because people fre- quently judge others on appearance more than on character, overweight children are often victims of prejudice. -many suffer discrimination by adults and rejection by their peers. -they may have poor self-images, a sense of failure, and a passive ap- proach to life. -television shows, which are a major influence in children s lives, of- ten portray the fat person as the bumbling misfit. -overweight children may come to accept this negative stereotype in themselves and in others, which can lead to addi- tional emotional and social problems. -researchers investigating children s reactions to various body types find that both normal-weight and underweight children re- spond unfavorably to overweight bodies. -prevention and treatment of obesity medical science has worked wonders in preventing or curing many of even the most serious childhood diseases, but obesity remains a challenge.95 once excess fat has been stored, it is challenging to lose. -in light of all this, parents are encouraged to make major efforts to prevent childhood tv fosters obesity because it: requires no energy beyond basal metab- olism replaces vigorous activities encourages snacking promotes a sedentary lifestyle playing video games influences children s activity patterns similarly. -television watching influences children s eating habits and activity patterns. -s i b r o c 570 chapter 16 obesity or to begin treatment early before adolescence.96 treatment must consider the many aspects of the problem and possible solutions. -the most successful ap- proach integrates diet, physical activity, psychological support, and behavioral changes.97 diet the initial goal for overweight children is to reduce the rate of weight gain; that is, to maintain weight while the child grows taller. -continued growth will then accom- plish the desired change in weight for height. -weight loss is usually not recommended because diet restriction can interfere with growth and development. -intervention for some older, overweight children with accompanying medical conditions may war- rant weight loss, but this treatment requires an individualized approach based on the degree of overweight and severity of the medical conditions.98 whether the goal is to treat or prevent obesity, the following strategies may be helpful: serve family meals that reflect kcalorie control both in the foods offered and in the ways foods are prepared. -involve children in shopping for food and preparing meals. -encourage children to eat only when they are hungry, to eat slowly, to pause and enjoy their table companions, and to stop eating when they are full. -teach them how to select nutrient-dense foods (low-fat and non-fat milk and milk products for children 3 years of age and older, fruits and vegetables, whole grains, legumes, fish, and lean meat) that will meet their nutrient needs within their energy allowances. -also, teach them to serve themselves appropriate portions at meals; the amount of food offered influences the amount of food eaten.99 limit foods high in saturated and trans fats (see table h5-1 in highlight 5) and high-sugar foods, including sugar-sweetened soft drinks. -never force children to clean their plates. -plan for snack times and provide a variety of nutritious snacks (see table 16- 8 later in this chapter). -discourage eating while watching tv. -dietary guidelines for americans 2005 help overweight children reduce the rate of body weight gain while allowing growth and development. -consult a healthcare provider before placing a child on a weight-reduction diet. -physical activity the many benefits of physical activity are well known but often are not enough to motivate overweight people, especially children. -yet regular vig- orous activity can improve a child s weight, body composition, and physical fit- ness.100 ideally, parents will limit sedentary activities and encourage daily physical activity to promote strong skeletal, muscular, and cardiovascular development and instill in their children the desire to be physically active throughout life. -most impor- tantly, parents need to set a good example. -physical activity is a natural and lifelong behavior of healthy living. -it can be as simple as riding a bike, playing tag, jumping rope, or doing chores. -it need not be an organized sport; it just needs to be some ac- tivity on a regular basis. -the aap supports the efforts of schools to include more physical activity in the curriculum and encourages parents to support their chil- dren s participation.101 psychological support weight-loss programs that involve parents and other caregivers in treatment report greater success than those without parental involve- ment. -because obesity in parents and their children tends to be positively correlated, both benefit when parents participate in a weight-loss program. -parental attitudes about food greatly influence children s eating behavior, so it is important that the in- fluence be positive. -otherwise, eating problems may become exacerbated. -life cycle nutrition: infancy, childhood, and adolescence 571 behavioral changes in contrast to traditional weight-loss programs that focus on what to eat, behavioral programs focus on how to eat. -these techniques involve changing learned habits that lead a child to eat excessively. -obesity is prevalent in our society. -because treatment of obesity is frequently unsuc- cessful, it is most important to prevent its onset. -above all, be sensible in teaching children how to maintain appropriate body weight. -children can easily get the im- pression that their worth is tied to their body weight. -parents and the media are most influential in shaping self-concept, weight concerns, and dieting practices.102 some parents fail to realize that society s ideal of slimness can be perilously close to starvation and that a child encouraged to diet cannot obtain the energy and nu- trients required for normal growth and development. -even healthy children with- out diagnosable eating disorders have been observed to limit their growth through dieting. -weight gain in truly overweight children can be managed without com- promising growth, but it should be overseen by a health care professional. -mealtimes at home traditionally, parents served as gatekeepers, determining what foods and activities were available in their children s lives. -then the children made their own selections. -gatekeepers who wanted to promote nutritious choices and healthful habits provided access to nutrient-dense, delicious foods and opportunities for active play at home. -in today s consumer-oriented society, children have greater influence over fam- ily decisions concerning food the fast-food restaurant the family chooses when eating out, the type of food the family eats at home, and the specific brands the family purchases at the grocery store. -parental guidance in food choices is still nec- essary, but teaching children consumer skills to help them make informed choices is equally important. -honoring children s preferences researchers attempting to explain children s food preferences encounter contradictions. -children say they like colorful foods, yet they most often reject green and yellow vegetables in favor of brown peanut butter and white potatoes, apple wedges, and bread. -they seem to like raw vegetables bet- ter than cooked ones, so it is wise to offer vegetables that are raw or slightly under- cooked, served separately, and easy to eat. -foods should be warm, not hot, because a child s mouth is much more sensitive than an adult s. the flavor should be mild because a child has more taste buds, and smooth foods such as mashed potatoes or split-pea soup should contain no lumps (a child wonders, with some disgust, what the lumps might be). -children prefer foods that are familiar, so offer various foods regularly. -make mealtimes fun for children. -young children like to eat at little tables and to be served small portions of food. -they like sandwiches cut in different geometric shapes and common foods called silly names. -they also like to eat with other chil- dren, and they tend to eat more when in the company of their friends. -children are also more likely to give up their prejudices against foods when they see their peers eating them. -learning through participation allowing children to help plan and prepare the family s meals provides enjoyable learning experiences and encourages children to eat the foods they have prepared. -vegetables are pretty, especially when fresh, and provide opportunities for children to learn about color, seeds, growing vegeta- bles, and shapes and textures all of which are fascinating to young children. -mea- suring, stirring, washing, and arranging foods are skills that even a young child can practice with enjoyment and pride (see table 16-7). -avoiding power struggles problems over food often arise during the second or third year, when children begin asserting their independence. -many of these prob- lems stem from the conflict between children s developmental stages and capabili- ties and parents who, in attempting to do what they think is best for their children, eating is more fun for children when friends are there. -e l i f r e t s a m table 16-7 childrena food skills of preschool age 1 to 2 years, when large muscles develop: uses short-shanked spoon helps feed self lifts and drinks from cup helps scrub, tear, break, or dip foods age 3 years, when medium hand muscles develop: spears food with fork feeds self independently helps wrap, pour, mix, shake, or spread foods helps crack nuts with supervision age 4 years, when small finger muscles develop: uses all utensils and napkin helps roll, juice, mash, or peel foods cracks egg shells age 5 years, when fine coordination of fingers and hands develops: helps measure, grind, grate, and cut (soft foods with dull knife) uses hand mixer with supervision athese ages are approximate. -healthy, normal children develop at their own pace. -gatekeepers: with respect to nutrition, key people who control other people s access to foods and thereby exert profound impacts on their nutrition. -examples are the spouse who buys and cooks the food, the parent who feeds the children, and the caregiver in a day-care center. -572 chapter 16 children enjoy eating the foods they help to prepare. -try to control every aspect of eating. -such conflicts can disrupt children s abilities to regulate their own food intakes or to determine their own likes and dislikes. -for ex- ample, many people share the misconception that children must be persuaded or coerced to try new foods. -in fact, the opposite is true. -when children are forced to try new foods, even by way of rewards, they are less likely to try those foods again than are children who are left to decide for themselves. -similarly, when children are re- stricted from eating their favorite foods, they are more likely to want those foods.103 wise parents provide healthful foods and allow their child to determine how much and even whether to eat. -when introducing new foods, offer them one at a time and only in small amounts such as one bite at first. -the more often a food is presented to a young child, the more likely the child will accept that food. -offer the new food at the be- ginning of the meal, when the child is hungry, and allow the child to make the de- cision to accept or reject it. -never make an issue of food acceptance. -choking prevention parents must always be alert to the dangers of choking. -a choking child is silent, so an adult should be present whenever a child is eating. -make sure the child sits when eating; choking is more likely when a child is running or falling. -(see p. 557 for a list of foods and nonfood items most likely to cause choking.) -e l i f r e t s a m playing first children may be more relaxed and attentive at mealtime if outdoor play or other fun activities are scheduled before, rather than immediately after, mealtime. -otherwise children hurry up and eat so that they can go play. -snacking parents may find that when their children snack, they aren t hungry at mealtimes. -instead of teaching children not to snack, parents are wise to teach them how to snack. -provide snacks that are as nutritious as the foods served at mealtime. -snacks can even be mealtime foods served individually over time, instead of all at once on one plate. -when providing snacks to children, think of the five food groups and offer such snacks as pieces of cheese, tangerine slices, and egg salad on whole- wheat crackers (see table 16-8). -snacks that are easy to prepare should be readily available to children, especially if they arrive home from school before their parents. -to ensure that children have healthy appetites and plenty of room for nutritious foods when they are hungry, parents and teachers must limit access to candy, soft drinks, and other concentrated sweets. -limiting access includes limiting the amount of pocket money children have to buy such foods themselves.104 if these foods are permitted in large quantities, the only possible outcomes are nutrient de- ficiencies, obesity, or both. -the preference for sweets is innate; most children do not naturally select nutritious foods on the basis of taste. -when children are allowed to create meals freely from a variety of foods, they typically select foods that provide a lot of sugar. -when their parents are watching, or even when they only think their parents are watching, children improve their selections. -sweets need not be banned altogether. -children who are exceptionally active can enjoy high-kcalorie foods such as ice cream or pudding from the milk group or pancakes from the bread group. -sedentary children need to become more active so they can also enjoy some of these foods without unhealthy weight gain. -preventing dental caries children frequently snack on sticky, sugary foods that stay on the teeth and provide an ideal environment for the growth of bacteria that cause dental caries. -teach children to brush and floss after meals, to brush or rinse af- ter eating snacks, to avoid sticky foods, and to select crisp or fibrous foods frequently. -serving as role models in an effort to practice these many tips, parents may over- look perhaps the single most important influence on their children s food habits themselves.105 parents who don t eat carrots shouldn t be surprised when their children refuse to eat carrots. -likewise, parents who comment negatively on the smell of brussels sprouts may not be able to persuade children to try them. -children learn much through imitation. -it is not surprising that children prefer the foods other fam- ily members enjoy and dislike foods that are never offered to them.106 parents, older life cycle nutrition: infancy, childhood, and adolescence 573 table 16-8 in combination healthful snack ideas think food groups, alone and selecting two or more foods from different food groups adds variety and nutrient balance to snacks. -the combinations are endless, so be creative. -whenever possible, choose whole grains, low fat or reduced fat milk products, and lean meats. -grains grain products are filling snacks, especially when combined with other foods: cereal with fruit and milk crackers and cheese whole-grain toast with peanut butter popcorn with grated cheese oatmeal raisin cookies with milk vegetables cut-up, fresh, raw vegetables make great snacks alone or in combination with foods from other food groups: celery with peanut butter broccoli, cauliflower, and carrot sticks with a flavored cottage cheese dip fruits fruits are delicious snacks and can be eaten alone fresh, dried, or juiced or combined with other foods: apples and cheese bananas and peanut butter peaches with yogurt raisins mixed with sunflower seeds or nuts meats and legumes meats and legumes add protein to snacks: refried beans with nachos and cheese tuna on crackers luncheon meat on whole-grain bread milk and milk products milk can be used as a beverage with any snack, and many other milk products, such as yogurt and cheese, can be eaten alone or with other foods as listed above. -siblings, and other caregivers set an irresistible example by sitting with younger chil- dren, eating the same foods, and having pleasant conversations during mealtimes. -while serving and enjoying food, caregivers can promote both physical and emotional growth at every stage of a child s life. -they can help their children de- velop both a positive self-concept and a positive attitude toward food. -with good beginnings, children will grow without the conflicts and confusions about food that can lead to nutrition and health problems. -nutrition at school while parents are doing what they can to establish good eating habits in their chil- dren at home, others are preparing and serving foods to their children at day-care centers and schools. -in addition, children begin to learn about food and nutrition in the classroom. -meeting the nutrition and education needs of children is critical to supporting their healthy growth and development.107 meals at school the u.s. government assists schools financially so that every stu- dent can receive nutritious meals at school. -both the school breakfast program and the american dietetic association has set nutrition standards for child-care programs. -among them, meal plans should include the following: be nutritionally adequate and consistent with the dietary guidelines for americans involve parents in planning follow recommended meal patterns that balance energy and nutrients with chil- dren s ages, appetites, activity levels, and special needs while respecting cultural and ethnic differences minimize added fat, sugar, and sodium emphasize fresh fruit, fresh and frozen vegetables, and whole grains provide furniture and eating utensils that are age appropriate and developmentally suitable to encourage children to accept and enjoy mealtime 574 chapter 16 school lunches provide children with nourish- ment at little or no charge. -the school breakfast must contain at a minimum: one serving of fluid milk one serving of fruit or vegetable or full- strength juice two servings of bread or bread alter- nates; or two servings of meat or meat alternates; or one of each t i d e t o h p / r e i z a r f d i v a d the national school lunch program provide meals at a reasonable cost to children from families with the financial means to pay. -meals are available free or at reduced cost to children from low-income families. -in addition, schools can obtain food com- modities. -nationally, the u.s. department of agriculture (usda) administers the programs; on the state level, state departments of education operate them. -* the pro- grams usually cost local school districts little, but the educational rewards are great. -several studies have reported that children who participate in school food programs perform better in the classroom.108 more than 28 million children receive lunches through the national school lunch program half of them free or at a reduced price.109 school lunches offer a variety of food choices and help children meet at least one-third of their recom- mended intakes for energy, protein, vitamin a, vitamin c, iron, and calcium. -table 16-9 shows school lunch patterns for children of different ages and specifies the numbers of servings of milk, protein-rich foods (meat, poultry, fish, cheese, eggs, legumes, or peanut butter), vegetables, fruits, and breads or other grain foods. -in an effort to help reduce disease risk, all government-funded meals served at schools must follow the dietary guidelines for americans. -parents often rely on school lunches to meet a significant part of their children s nutrient needs on school days. -indeed, students who regularly eat school lunches have higher intakes of many nutrients and fiber than students who do not.110 the school breakfast program is available in more than 80 percent of the na- tion s schools that offer school lunch, and close to 9 million children participate in it.111 nevertheless, for many children who need it, the school breakfast program is ei- ther unavailable, or the children do not participate in it.112 the majority of children who eat school breakfasts are from low-income families. -as research results continue to emphasize the positive impact breakfast has on school performance and health, vigorous campaigns to expand school breakfast programs are under way. -table 16-9 school lunch patterns for different agesa food group preschool (age) grade school through high school (grade) 1 to 2 3 to 4 k to 3 4 to 6 7 to 12 meat or meat alternate 1 serving: lean meat, poultry, or fish cheese large egg(s) cooked dry beans or peas peanut butter yogurt peanuts, soynuts, tree nuts, or seedsb vegetable and/or fruit 2 or more servings, both to total bread or bread alternatec servings milk 1 serving of fluid milk 1 oz 1 oz 1 2 1 4 c 2 tbs 1 2 c 1 2 oz 11 2 oz 11 2 oz 3 4 3 8 c 3 tbs 3 4 c 3 4 oz 11 2 oz 11 2 oz 3 4 3 8 c 3 tbs 3 4 c 3 4 oz 2 oz 2 oz 1 1 2 c 4 tbs 1 c 1 oz 3 oz 3 oz 11 2 3 4 c 6 tbs 11 2 c 11 2 oz 1 2 c 1 2 c 1 2 c 3 4 c 3 4 c 5/week 8/week 8/week 8/week 10/week 3 4 c 3 4 c 1 c 1 c 1 c athe quantities listed represent per-lunch minimums for each age and grade except those for the oldest group, which are recommendations. -schools unable to serve the recommended quantities for grades 7 to 12 must provide at least the amount shown for grades 4 to 6. bthese meat alternates may be used to meet no more than half of the meat or meat alternate requirement; therefore, they must be used in a meal with another meat or meat alternate. -cschools must serve daily at least 1 2 serving of bread or bread alternate to the youngest age group and at least 1 serving to older children. -source: u.s. department of agriculture, national school lunch program regulations, revised january 1, 1998. -*school lunches in canada are administered locally and therefore vary from area to area. -life cycle nutrition: infancy, childhood, and adolescence 575 another federal program, the child and adult care food program (cacfp), op- erates similarly and provides funds to organized child-care programs. -all eligible children, centers, and family day-care homes may participate. -sponsors are reim- bursed for most meal costs and may also receive usda commodity foods. -competing influences at school serving healthful lunches is only half the bat- tle; students need to eat them, too. -short lunch periods and long waiting lines pre- vent some students from eating a school lunch and leave others with too little time to complete their meals.113 nutrition efforts at schools are also undermined when students can buy what the usda labels competitive foods meals from fast-food restaurants or a la carte foods such as pizza or snack foods and carbonated bever- ages from snack bars, school stores, and vending machines.114 in one study, students who selected competitive foods in addition to, or instead of, school meals consumed more energy and fat and less calcium and vitamin a than those who selected only the school lunch.115 increasingly, school-based nutrition issues are being addressed by legislation. -some states restrict the sale of competitive foods and have higher rates of participa- tion in school meal programs than the national average. -federal legislation man- dates that all school districts that participate in the usda s national school lunch program develop and put in place a local wellness policy.116 nutrition profession- als advocate further legislative measures that would prohibit sales of food and bev- erages from vending machines or school stores in middle and high schools until 30 minutes after the end of the last meal unless they are part of the school foodservice and meet dietary guidelines standards.117 reducing the prices of nutritious foods also greatly increases the likelihood that students will purchase them.118 in summary children s appetites and nutrient needs reflect their stage of growth. -those who are chronically hungry and malnourished suffer growth retardation; when hunger is temporary and nutrient deficiencies are mild, the problems are usually more subtle such as poor academic performance. -iron deficiency is widespread and has many physical and behavioral consequences. -hyper behavior is not caused by poor nutrition; misbehavior may be due to lack of sleep, too little physical activity, or too much television, among other things. -childhood obesity has become a major health problem. -adults at home and at school need to provide children with nutrient-dense foods and teach them how to make healthful diet and activity choices. -nutrition during adolescence teenagers make many more choices for themselves than they did as children. -they are not fed, they eat; they are not sent out to play, they choose to go. -at the same time, social pressures thrust choices at them, such as whether to drink alcoholic bev- erages and whether to develop their bodies to meet extreme ideals of slimness or athletic prowess. -their interest in nutrition both valid information and misinforma- tion derives from personal, immediate experiences. -they are concerned with how diet can improve their lives now they engage in fad dieting in order to fit into a new bathing suit, avoid greasy foods in an effort to clear acne, or eat a pile of spaghetti to prepare for a big sporting event. -in presenting information on the nutrition and health of adolescents, this section includes many topics of interest to teens. -growth and development with the onset of adolescence, the steady growth of childhood speeds up abruptly and dramatically, and the growth patterns of female and male become distinct. -adolescence: the period from the beginning of puberty until maturity. -576 chapter 16 nutritious snacks contribute valuable nutrients to an active teen s diet. -s e g a m i y t t e g / e c r u o s e g a m i hormones direct the intensity of the adolescent growth spurt, profoundly affecting every organ of the body, including the brain. -after two to three years of intense growth and a few more at a slower pace, physically mature adults emerge. -in general, the adolescent growth spurt begins at age 10 or 11 for females and at 12 or 13 for males. -it lasts about two and a half years. -before puberty, male and female body compositions differ only slightly, but during the adolescent spurt, dif- ferences between the genders become apparent in the skeletal system, lean body mass, and fat stores. -in females, fat assumes a larger percentage of the total body weight, and in males, the lean body mass principally muscle and bone in- creases much more than in females (review figure 8-8, p. 261). -on average, males grow 8 inches taller, and females, 6 inches taller. -males gain approximately 45 pounds, and females, about 35 pounds. -energy and nutrient needs energy and nutrient needs are greater during adolescence than at any other time of life, except pregnancy and lactation. -in general, nutrient needs rise throughout childhood, peak in adolescence, and then level off or even diminish as the teen be- comes an adult. -energy intake and activity the energy needs of adolescents vary greatly, de- pending on their current rate of growth, gender, body composition, and physical ac- tivity.119 boys energy needs may be especially high; they typically grow faster than girls and, as mentioned, develop a greater proportion of lean body mass. -an excep- tionally active boy of 15 may need 3500 kcalories or more a day just to maintain his weight. -girls start growing earlier than boys and attain shorter heights and lower weights, so their energy needs peak sooner and decline earlier than those of their male peers. -a sedentary girl of 15 whose growth is nearly at a standstill may need fewer than 1800 kcalories a day if she is to avoid excessive weight gain. -thus ado- lescent girls need to pay special attention to being physically active and selecting foods of high nutrient density so as to meet their nutrient needs without exceeding their energy needs. -dietary guidelines for americans 2005 adolescents should engage in at least 60 minutes of physical activity on most, preferably all, days of the week. -the insidious problem of obesity becomes ever more apparent in adolescence and often continues into adulthood. -the problem is most evident in females of african american descent and in hispanic children of both genders. -without inter- vention, overweight adolescents face numerous physical and socioeconomic conse- quences for years to come. -the consequences of obesity are so dramatic and our society s attitude toward obese people is so negative that even teens of normal or be- low-normal weight may perceive a need to lose weight. -when taken to extremes, re- strictive diets bring dramatic physical consequences of their own, as highlight 8 explained. -vitamins the rda (or ai) for most vitamins increases during the adolescent years (see the table on the inside front cover). -several of the vitamin recommendations for adolescents are similar to those for adults, including the recommendation for vita- min d. during puberty, both the activation of vitamin d and the absorption of cal- cium are enhanced, thus supporting the intense skeletal growth of the adolescent years without additional vitamin d. puberty: the period in life in which a person becomes physically capable of reproduction. -iron the need for iron increases during adolescence for both females and males, but for different reasons. -iron needs increase for females as they start to menstruate life cycle nutrition: infancy, childhood, and adolescence 577 iron rda for males: 9 13 yr: 8 mg/day 9 13 yr in growth spurt: 10.9 mg/day 14 18 yr: 11 mg/day 14 18 yr in growth spurt: 13.9 mg/day iron rda for females: 9 13 yr: 8 mg/day 9 13 yr in menarche: 10.5 mg/day 9 13 yr in menarche and growth spurt: 11.6 mg/day 14 18 yr: 15 mg/day 14 18 yr in growth spurt: 16.1 mg/day and for males as their lean body mass develops. -hence, the rda increases at age 14 for both males and females. -for females, the rda remains high into late adulthood. -for males, the rda returns to preadolescent values in early adulthood. -in addition, iron needs increase when the adolescent growth spurt begins, whether that occurs before or after age 14. therefore, boys in a growth spurt need an additional 2.9 milligrams of iron per day above the rda for their age; girls need an additional 1.1 milligrams per day.120 furthermore, iron recommendations for girls before age 14 do not reflect the iron losses of menstruation. -the average age of menarche (first menstruation) in the united states is 12.5 years, however.121 therefore, for girls under the age of 14 who have started to menstruate, an additional 2.5 milligrams of iron per day is rec- ommended.122 thus the rda for iron depends not only on age and gender but also on whether the individual is in a growth spurt or has begun to menstruate, as listed in the margin. -iron intakes often fail to keep pace with increasing needs, especially for females, who typically consume less iron-rich foods such as meat and fewer total kcalories than males. -not surprisingly, iron deficiency is most prevalent among adolescent girls. -iron-deficient children and teens score lower on standardized tests than those who are not iron deficient. -calcium adolescence is a crucial time for bone development, and the requirement for calcium reaches its peak during these years.123 unfortunately, low calcium intakes among adolescents have reached crisis proportions: 90 percent of females and 70 per- cent of males ages 12 to 19 years have calcium intakes below recommendations.124 low calcium intakes during times of active growth, especially if paired with physical inactivity, can compromise the development of peak bone mass, which is considered the best protection against adolescent fractures and adult osteoporosis. -increasing milk products in the diet to meet calcium recommendations greatly increases bone density.125 once again, however, teenage girls are most vulnerable, for their milk and therefore their calcium intakes begin to decline at the time when their calcium needs are greatest.126 furthermore, women have much greater bone losses than men in later life. -in addition to dietary calcium, bones grow stronger with physical activity. -however, because few high schools require students to attend physical education classes, most adolescents must make a point to be physically active during leisure time. -dietary guidelines for americans 2005 children 9 years of age and older should consume 3 cups per day of fat- free or low-fat milk or equivalent milk products. -food choices and health habits teenagers like the freedom to come and go as they choose. -they eat what they want if it is convenient and if they have the time.127 with a multitude of afterschool, social, and job activities, they almost inevitably fall into irregular eating habits. -at any given time on any given day, a teenager may be skipping a meal, eating a snack, preparing a meal, or consuming food prepared by a parent or restaurant. -adoles- cents who frequently eat meals with their families, however, eat more fruits, vegeta- bles, grains, and calcium-rich foods, and drink fewer soft drinks, than those who seldom eat with their families.128 furthermore, the more often teenagers eat dinner with their families, the less likely they are to smoke, drink, or use drugs.129 many ado- lescents also begin to skip breakfast on a regular basis, missing out on important nu- trients that are not made up at later meals during the day. -compared with those who skip breakfast, teenagers who do eat breakfast have higher intakes of vitamins a, c, and riboflavin, as well as calcium, iron, and zinc.130 teenagers who eat breakfast are therefore more likely to meet their nutrient intake recommendations. -578 chapter 16 because their lunches rarely include fruits, veg- etables, or milk, many teens fail to get all the vitamins and minerals they need each day. -for perspective, caffeine-containing soft drinks typically deliver between 30 and 55 mg of caffeine per 12-ounce can. -a phar- macologically active dose of caffeine is defined as 200 mg. appendix h starts with a table listing the caffeine contents of selected foods, beverages, and drugs. -s e g a m i y t t e g / t r e k c a p e t i h w ideally, in light of adolescents busy schedules and desire for freedom, the adult continues to play the role of gatekeeper, controlling the type and availability of food in the teenager s environment. -teenagers should find plenty of nutritious, easy-to-grab foods in the refrigerator (meats for sandwiches; low-fat cheeses; fresh, raw vegetables and fruits; fruit juices; and milk) and more in the cabinets, (whole- grain breads, peanut butter, nuts, popcorn, and cereal). -in many households today, the adults work outside the home, and teenagers perform some of the gatekeepers roles, such as shopping for groceries or choosing fast or prepared foods. -snacks snacks typically provide at least a fourth of the average teenager s daily food energy intake. -most often, favorite snacks are too high in saturated fat and sodium and too low in fiber to support the future health of the arteries.131 table 16-8, p. 573 shows how to combine foods from different food groups to create healthy snacks. -beverages most frequently, adolescents drink soft drinks instead of fruit juice or milk with lunch, supper, and snacks. -about the only time they select fruit juices is at breakfast. -when teens drink milk, they are more likely to consume it with a meal (especially breakfast) than as a snack. -soft drinks, when chosen as the primary bev- erage, may affect bone density because they displace milk from the diet.132 because of their greater food intakes, boys are more likely than girls to drink enough milk to meet their calcium needs. -over the past three decades, teens (especially girls) have been drinking more soft drinks and less milk.133 adolescents who drink soft drinks regularly have a higher energy intake and a lower calcium intake than those who do not; they are also more likely to be overweight.134 soft drinks containing caffeine present a different problem if caffeine intake becomes excessive. -caffeine seems to be relatively harmless when used in moder- ate doses (the equivalent of fewer than three 12-ounce cola beverages a day). -in greater amounts, however, it can cause the symptoms associated with anxiety, such as sweating, tenseness, and inability to concentrate. -eating away from home adolescents eat about one-third of their meals away from home, and their nutritional welfare is enhanced or hindered by the choices they make. -a lunch consisting of a hamburger, a chocolate shake, and french fries supplies substantial quantities of many nutrients at a kcalorie cost of about 800, an energy intake some adolescents can afford. -when they eat this sort of lunch, teens can adjust their breakfast and dinner choices to include fruits and vegetables for vi- tamin a, vitamin c, folate, and fiber and lean meats and legumes for iron and zinc. -(see appendix h for the nutrient contents of fast foods.) -fortunately, many fast food restaurants are offering more nutritious choices than the standard hamburger meal. -peer influence many of the food and health choices adolescents make reflect the opinions and actions of their peers. -when others perceive milk as babyish, a teen may choose soft drinks instead; when others skip lunch and hang out in the park- ing lot, a teen may join in for the camaraderie, regardless of hunger. -adults need to remember that adolescents have the right to make their own decisions even if they are contrary to the adults views. -gatekeepers can set up the environment so that nutritious foods are available and can stand by with reliable nutrition information and advice, but the rest is up to the adolescents. -ultimately, they make the choices. -(highlight 8 examines the influence of social pressures on the development of eat- ing disorders.) -problems adolescents face physical maturity and growing independence present adolescents with new choices. -the consequences of those choices will influence their nutritional health both today and throughout life. -some teenagers begin using drugs, alcohol, and tobacco; oth- ers wisely refrain. -information about the use of these substances is presented here because most people are first exposed to them during adolescence, but it actually applies to people of all ages. -life cycle nutrition: infancy, childhood, and adolescence 579 marijuana almost half of the high school students in the united states report hav- ing at least tried marijuana.135 marijuana is unique among drugs in that it seems to enhance the enjoyment of eating, especially of sweets, a phenomenon commonly known as the munchies. -prolonged use of marijuana, however, does not seem to bring about a weight gain. -cocaine, crack, and methamphetamine cocaine, crack, and methampheta- mine stimulate the nervous system and elicit the stress response constricted blood vessels, raised blood pressure, dilated pupils, and increased body temperature. -these drugs also drive away feelings of fatigue. -they occasionally cause immediate death usually by heart attack, stroke, or seizure in an already damaged body system. -dur- ing prolonged episodes of drug use, abusers suffer dehydration and electrolyte imbalances. -decreases in appetite, weight loss, and malnutrition are common. -no- tably, the craving for these drugs replaces hunger; rats given unlimited cocaine will choose it over food until they starve to death. -thus, unlike marijuana use, cocaine, crack, and methamphetamine use has major nutritional consequences. -ecstasy the club drug ecstasy has become alarmingly popular in recent years. -ec- stasy signals the nerve cells to dump all their stored serotonin at once and then prevents its reabsorption. -the rush of serotonin flooding the gap between the nerve cells (the synapse) alters a person s mood, but it may also damage nerve cells and im- pair memory. -because serotonin helps to regulate body temperature, overheating is a common and potentially dangerous side effect of this drug. -people who use ecstasy regularly tend to lose weight. -drug abuse, in general the nutrition problems associated with other drugs vary in degree, but drug abusers in general face multiple nutrition problems. -dur- ing withdrawal from drugs, an important part of treatment is to identify and correct nutrient deficiencies. -alcohol abuse sooner or later all teenagers face the decision of whether to drink alcohol. -the law forbids the sale of alcohol to people under 21, but most adolescents who want it can get it. -by the end of high school, 77 percent of students have tried alcohol, and about half have been drunk at least once.136 highlight 7 describes how alcohol affects nutrition status. -to sum it up, alcohol provides energy but no nutri- ents, and it can displace nutritious foods from the diet. -alcohol alters nutrient ab- sorption and metabolism, so imbalances develop. -people who cannot keep their alcohol use moderate must abstain to maintain their health. -highlight 7 lists re- sources for people with alcohol-related problems. -smoking slightly less than 30 percent of u.s. high school students report smoking a cigarette in the previous month.137 this is the lowest rate of smoking among high school students since 1991. cigarette smoking is a pervasive health problem caus- ing thousands of people to suffer from cancer and diseases of the cardiovascular, di- gestive, and respiratory systems. -these effects are beyond the scope of nutrition, but smoking cigarettes does influence hunger, body weight, and nutrient status. -smoking a cigarette eases feelings of hunger. -when smokers receive a hunger signal, they can quiet it with cigarettes instead of food. -such behavior ignores body signals and postpones energy and nutrient intake. -indeed, smokers tend to weigh less than nonsmokers and to gain weight when they stop smoking. -people contem- plating giving up cigarettes should know that the average weight gain is about 10 pounds in the first year. -smokers wanting to quit should prepare for the possibility of weight gain and adjust their diet and activity habits so as to maintain weight during and after quitting. -smoking cessation programs need to include strategies for weight management. -nutrient intakes of smokers and nonsmokers differ. -smokers tend to have lower intakes of dietary fiber, vitamin a, beta-carotene, folate, and vitamin c. the asso- ciation between smoking and low intakes of fruits and vegetables rich in these nu- trients may be noteworthy, considering their protective effect against lung cancer (see highlight 11). -reminder: serotonin is a neurotransmitter important in the regulation of appetite, sleep, and body temperature. -nutrition problems of drug abusers: they buy drugs with money that could be spent on food. -they lose interest in food during highs. -they use drugs that suppress appetite. -their lifestyle fails to promote good eat- ing habits. -if they use intravenous (iv) drugs, they may contract aids, hepatitis, or other infectious diseases, which increase their nutrient needs. -hepatitis also causes taste changes and loss of appetite. -medicines used to treat drug abuse may alter nutrition status. -580 chapter 16 the vitamin c requirement for people who regularly smoke cigarettes is an additional 35 mg/day. -compared with nonsmokers, smokers require more vitamin c to maintain steady body pools. -oxidants in cigarette smoke accelerate vitamin c metabolism and deplete smokers body stores of this antioxidant. -this depletion is even evident to some degree in nonsmokers who are exposed to passive smoke.138 beta-carotene enhances the immune response and protects against some cancer activity. -specifically, the risk of lung cancer is greatest for smokers who have the lowest intakes. -of course, such evidence should not be misinterpreted. -it does not mean that as long as people eat their carrots, they can safely use tobacco. -nor does it mean that beta-carotene supplements are beneficial; smokers taking beta- carotene supplements actually had a higher incidence of lung cancer and risk of death than those taking a placebo. -(see highlight 11 for more details.) -smokers are ten times more likely to get lung cancer than nonsmokers. -both smokers and non- smokers, however, can reduce their cancer risks by eating fruits and vegetables rich in antioxidants. -(see highlight 11 for details on antioxidant nutrients and disease prevention.) -smokeless tobacco like cigarettes, smokeless tobacco use is linked to many health problems, from minor mouth sores to tumors in the nasal cavities, cheeks, gums, and throat. -the risk of mouth and throat cancers is even greater than for smoking to- bacco. -other drawbacks to tobacco chewing and snuff dipping include bad breath, stained teeth, and blunted senses of smell and taste. -tobacco chewing also damages the gums, tooth surfaces, and jawbones, making teeth loss later in life likely. -the nutrition and lifestyle choices people make as children and adolescents have long-term, as well as immediate, effects on their health. -highlight 16 describes how sound choices and good habits during childhood and adolescence can help prevent chronic diseases later in life. -www.thomsonedu.com/thomsonnow nutrition portfolio encouraging children to eat nutritious foods today helps them learn how to make healthy food choices tomorrow. -if there are children in your life, think about the food they eat and consider whether they receive enough food for healthy growth, but not so much as to lead to obesity. -describe the advantages of physical activity to children s health and well-being. -plan a day s menu for a child 4 to 8 years of age, making sure to include foods that provide enough calcium and iron. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 16, then to nutrition on the net. -learn more about breast milk banks from the human milk banking association of north america: www.hmbana.com search for infants, baby bottle tooth decay, prema- ture birth, hyperactivity, food allergies, and adoles- cent health, at the u.s. government health information site: www.healthfinder.gov learn how to care for infants, children, and adolescents from the american academy of pediatrics and the cana- dian paediatric society: www.aap.org and www.cps.ca download the current growth charts and learn about their most recent revision: www.cdc.gov/growthcharts get information on the food guide pyramid for young children from the usda: www.mypyramid.gov/kids get tips for feeding children from the american dietetic association: www.eatright.org life cycle nutrition: infancy, childhood, and adolescence 581 get tips for keeping children healthy from the nemours visit the milk matters section of the national institute of foundation: www.kidshealth.org visit the national center for education in maternal & child health and the national institute of child health and human development: www.ncemch.org and www.nichd.nih.gov child health and human development (nichd): www.nichd.nih.gov learn more about caffeine from the international food information council: www.ific.org to learn about healthy foods and to find recipes and ideas learn about the child nutrition programs: for physical activities, visit: www.kidnetic.com www.fns.usda.gov/fns get weight-loss tips for children and adolescents: learn how unicef works to protect children: www.shapedown.com www.unicef.org learn how to reduce lead exposure in your home from the u.s. department of housing and urban development office of lead hazard control: www.hud.gov/lead learn more about food allergies from the american acad- emy of allergy, asthma, and immunology; the food al- lergy network; and the international food information council: www.aaaai.org, www.foodallergy.org, and www.ific.org learn more about hyperactivity from children and adults with attention deficit/hyperactivity disorders: www.chadd.org study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. describe some of the nutrient and immunological attri- butes of breast milk. -(pp. -550 552) 2. what are the appropriate uses of formula feeding? -what criteria would you use in selecting an infant formula? -(pp. -552 553) 3. why are solid foods not recommended for an infant during the first few months of life? -when is an infant ready to start eating solid food? -(pp. -555 557) 4. identify foods that are inappropriate for infants and explain why they are inappropriate. -(pp. -554, 556 557) 5. what nutrition problems are most common in children? -what strategies can help prevent these problems? -(pp. -562 564) 6. describe the relationships between nutrition and behavior. -how does television influence nutrition? -(pp. -564 565, 569) 7. describe a true food allergy. -which foods most often cause allergic reactions? -how do food allergies influence nutrition status? -(pp. -565 567) learn about nondietary approaches to weight loss from hugs international: www.hugs.com read the message for parents and teens on the risks of tobacco use from the american academy of pediatrics: www.aap.org get help quitting smoking at quitnet: www.quitnet.com visit the tobacco information and prevention source (tips) of the centers for disease control and prevention: www.cdc.gov/tobacco/sgr/sgr_2000 8. describe the problems associated with childhood obesity and the strategies for prevention and treatment. -(pp. -567 571) 9. list strategies for introducing nutritious foods to chil- dren. -(pp. -571 573) 10. what impact do school meal programs have on the nu- trition status of children? -(pp. -573 575) 11. describe the changes in nutrient needs from childhood to adolescence. -why is an adolescent girl more likely to develop an iron deficiency than is a boy? -(pp. -575 577) 12. how do adolescents eating habits influence their nutri- ent intakes? -(pp. -577 578) 13. how does the use of illicit drugs influence nutrition status? -(p. 579) 14. how do the nutrient intakes of smokers differ from those of nonsmokers? -what impacts can those differences exert on health? -(pp. -579 580) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 585. -1. a reasonable weight for a healthy five-month-old infant who weighed 8 pounds at birth might be: a. -12 pounds. -b. -16 pounds. -c. 20 pounds. -d. 24 pounds. -582 chapter 16 2. dehydration can develop quickly in infants because: a. much of their body water is extracellular. -b. they lose a lot of water through urination and tears. -c. only a small percentage of their body weight is water. -7. to help teenagers consume a balanced diet, parents can: a. monitor the teens food intake. -b. give up parents can t influence teenagers. -c. keep the pantry and refrigerator well stocked. -d. forbid snacking and insist on regular, well- d. they drink lots of breast milk or formula, but little balanced meals. -water. -3. an infant should begin eating solid foods between: a. -2 and 4 weeks. -b. -1 and 3 months. -c. 4 and 6 months. -d. 8 and 10 months. -8. during adolescence, energy and nutrient needs: a. reach a peak. -b. fall dramatically. -c. rise, but do not peak until adulthood. -d. fluctuate so much that generalizations can t be made. -4. among u.s. and canadian children, the most prevalent 9. the nutrients most likely to fall short in the adolescent nutrient deficiency is of: diet are: a. iron. -b. folate. -c. protein. -d. vitamin d. 5. a true food allergy always: a. elicits an immune response. -b. causes an immediate reaction. -c. creates an aversion to the offending food. -d. involves symptoms such as headaches or hives. -6. which of the following strategies is not effective? -a. play first, eat later. -b. provide small portions. -c. encourage children to help prepare meals. -d. use dessert as a reward for eating vegetables. -a. sodium and fat. -b. folate and zinc. -c. iron and calcium. -d. protein and vitamin a. -10. to balance the day s intake, an adolescent who eats a hamburger, fries, and cola at lunch might benefit most from a dinner of: a. fried chicken, rice, and banana. -b. ribeye steak, baked potato, and salad. -c. pork chop, mashed potatoes, and apple juice. -d. spaghetti with meat sauce, broccoli, and milk. -references 1. committee on dietary reference intakes, dietary reference intakes for energy, carbohy- drate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (washington, d.c.: national academies press, 2005). -2. committee on dietary reference intakes, 2005, pp. -280-281. -3. committee on nutrition, american acad- emy of pediatrics, pediatric nutrition hand- book, 5th ed., ed. -r. e. kleinman (elk grove village, ill.: american 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years, journal of the american dietetic association 104 (2004): 660-677; 2004; k. w. cullen and i. zakeri, fruits, vegetables, milk, and sweetened beverages consumption and access to a la carte/snack bar meals at school, american journal of public health 94 (2004): 463-467; p. m. gleason and c. w. suitor, eating at school: how the national school lunch program affects children s diets, american journal of agricultural economics 85 (2003): 1047-1051. -111. position of the american dietetic associa- tion, 2006. -112. position of the american dietetic associa- tion, 2006. -113. position of the american dietetic associa- tion, 2006. -114. position of the american dietetic associa- tion, 2006; c. probart and coauthors, com- petitive foods available in pennsylvania public high schools, journal of the american dietetic association 105 (2005): 1243-1249; cullen and zakeri, 2004; committee on school health, american academy of pedi- atrics, soft drinks in schools, pediatrics 113 (2004): 152-154. life cycle nutrition: infancy, childhood, and adolescence 585 adolescence, adult bone density, and osteo- porotic fractures in us women, american journal of clinical nutrition 77 (2003): 257-265. -126. s. a. bowman, beverage choices of young females: changes and impact on nutrient intakes, journal of the american dietetic association 102 (2002): 1234-1239. -127. m. story, d. neumark-sztainer, and s. french, individual and environmental influences on adolescent eating behaviors, journal of the american dietetic association 102 (2002): s40-s51. -128. d. neumark-sztainer and coauthors, family meal patterns: associations with sociodemographic characteristics and im- proved dietary intake among adolescents, journal of the american dietetic association 103 (2003): 317-322. -129. national center on addiction and sub- stance abuse (casa) at columbia univer- sity, the importance of family dinners, september, 2003. -130. rampersaud and coauthors, 2005. -131. american heart association, s. s. gidding and coauthors, dietary recommendations for children and adolescents: a guide for practitioners, pediatrics 117 (2006): 544-559. -132. greer, krebs, and the committee on nutri- tion, 2006; h. vatanparast and coauthors, positive effects of vegetable and fruit con- sumption and calcium intake on bone mineral accrual in boys during growth from childhoodto adolescence: the university of saskatchewan pediatric bone mineral ac- crual study, american journal of clinical nutrition 82 (2005): 700-706; g. mrdjenovic and d. a. levitsky, nutritional and energetic consequences of sweetened drink consump- tion in 6- to 13-year-old children, journal of pediatrics 142 (2003): 604-610. -133. s. a. french, b. h. lin, and j. f. guthrie, national trends in soft drink consumption among children and adolescents age 6 to 17 years: prevalence, amounts, and sources, 1997/1978 to 1994/1998, journal of the american dietetic association 103 (2003): 1326-1331; bowman, 2002. -134. j. james and coauthors, preventing child- hood obesity by reducing consumption of carbonated drinks: cluster randomised controlled trial, british medical journal 328 (2004): 1237. -135. american academy of pediatrics, j. w. king and committee on substance abuse, tobacco, alcohol, and other drugs: the role of the pediatrician in prevention, identifica- tion, and management of substance abuse, pediatrics 115 (2005): 816-821. -136. american academy of pediatrics, king and committee on substance abuse, 2005. -137. centers for disease control and preven- tion, youth tobacco surveillance united states, 2001-2002, morbidity and mortality weekly report 55 (2006): entire supplement. -138. a. m. preston and coauthors, influence of environmental tobacco smoke on vitamin c status in children, american journal of clini- cal nutrition 77 (2003): 167-172. -115. s. b. templeton and coauthors, competi- tive foods increase the intake of energy and decrease the intake of certain nutrients by adolescents consuming school lunch, jour- nal of the american dietetic association 105 (2005): 215-220. -116. position of the american dietetic associa- tion, 2006. -117. position of the american dietetic associa- tion, society for nutrition education, and american school food service association, nutrition services: an essential component of comprehensive school health programs, journal of the american dietetic association 103 (2003): 505-514. -118. s. a. french, pricing effects on food choices, journal of nutrition 133 (2003): 841s-843s. -119. committee on dietary reference intakes, 2005, chapter 5. -120. committee on dietary reference intakes, 2001, pp. -290-393. -121. w. c. chumlea and coauthors, age at menarche and racial comparisons in us girls, pediatrics 111 (2003): 110-113. -122. committee on dietary reference intakes, 2001, pp. -290-393. -123. f. r. greer, n. f. krebs, and the committee on nutrition, american academy of pedi- atrics, optimizing bone health and calcium intakes of infants, children, and adolescents, pediatrics 117 (2006): 578-585. -124. greer, krebs, and the committee on nutri- tion, 2006. -125. h. j. kalkwarf, j. c. khoury, and b. p. lanphear, milk intake during childhood and answers study questions (multiple choice) 1. b 2. a 3. c 4. a 5. a 6. d 7. c 8. a 9. c 10. d highlight 16 highlight childhood obesity and the early development of chronic diseases when people think about the health problems of children and adolescents, they typically think of ear infections, colds, and acne not heart disease, diabetes, or hypertension. -to- day, however, unprecedented numbers of u.s. children are being diagnosed with obesity and the serious adult diseases, such as type 2 di- abetes, that accompany overweight.1 when type 2 diabetes develops before the age of 20, the incidence of diabetic kidney disease and death in middle age increases dramatically, largely because of the long duration of the dis- ease.2 for children born in the united states in the year 2000, the risk of developing type 2 diabetes sometime in their lives is esti- mated to be 30 percent for boys and 40 percent for girls.3 u.s. chil- dren are not alone rapidly rising rates of obesity threaten the health of an alarming number of children around the globe.4 with- out immediate intervention, millions of children are destined to de- velop type 2 diabetes and hypertension in childhood followed by cardiovascular disease (cvd) in early adulthood. -this highlight focuses on efforts to prevent childhood obesity and the development of heart disease and type 2 diabetes, but the benefits extend to other obesity-related diseases as well. -the years of childhood (ages 2 to 18) are emphasized here, because the earlier in life health-promoting habits become established, the better they will stick. -chapter 18 fills in the rest of the story of nutrition s role in reducing chronic disease risk. -invariably, questions arise as to what extent genetics is in- volved in disease development. -for heart disease and type 2 dia- betes, genetics does not appear to play a determining role; that is, a person is not simply destined at birth to develop these diseases. -instead, genetics appears to play a permissive role the potential is inherited and will develop if given a push by poor health choices such as excessive weight gain, poor diet, sedentary lifestyle, and cigarette smoking. -many experts agree that preventing or treating obesity in childhood will reduce the rate of chronic diseases in adulthood. -without intervention, most overweight children become over- weight adolescents who become overweight adults, and being overweight exacerbates every chronic disease that adults face.5 early development of type 2 diabetes in recent years, type 2 diabetes, a chronic disease closely linked with obesity, has been on the rise among children and adolescents 586 as the prevalence of obesity in u.s. youth has increased.6 obesity is the most important risk factor for type 2 diabetes most of the chil- dren diagnosed with it are obese.7 most are diagnosed during puberty, but as children be- come more obese and less active, the trend is shifting to younger children. -type 2 diabetes is most likely to occur in those who are obese and sedentary and have a family history of diabetes. -s e g a m i y t t e g / k n a b s e g a m i e h t / r e k a t i h w s s o r in type 2 diabetes, the cells become in- sulin-resistant that is, the cells become less sensitive to insulin, reducing the amount of glucose entering the cells from the blood. -the combination of obesity and insulin re- sistance produces a cluster of symptoms, including high blood cholesterol and high blood pressure, which, in turn, promotes the development of atherosclerosis and the early development of cvd.8 other common problems evident by early adulthood in- clude kidney disease, blindness, and miscarriages. -the complica- tions of diabetes, especially when encountered at a young age, can shorten life expectancy. -prevention and treatment of type 2 diabetes depend on weight management, which can be particularly difficult in a youngster s world of food advertising, video games, and pocket money for candy bars. -the activity and dietary suggestions to help defend against heart disease later in this highlight apply to type 2 diabetes as well. -early development of heart disease most people consider heart disease to be an adult disease because its incidence rises with advancing age, and symptoms rarely appear before age 30. the disease process actually begins much earlier. -atherosclerosis most cardiovascular disease involves atherosclerosis (see the glossary, p. 587 for this and related terms). -atherosclerosis devel- ops when regions of an artery s walls become progressively thick- ened with plaque an accumulation of fatty deposits, smooth muscle cells, and fibrous connective tissue. -if it progresses, ather- osclerosis may eventually block the flow of blood to the heart and cause a heart attack or cut off blood flow to the brain and cause a stroke. -infants are born with healthy, smooth, clear arteries, but within the first decade of life, fatty streaks may begin to appear childhood obesity and the early development of chronic diseases 587 g lossary atherosclerosis (ath-er-oh-scler- oh-sis): a type of artery disease characterized by plaques (accumulations of lipid- containing material) on the inner walls of the arteries (see chapter 18). -athero (cid:2) porridge or soft scleros (cid:2) hard osis (cid:2) condition cardiovascular disease (cvd): a general term for all diseases of the heart and blood vessels. -atherosclerosis is the main cause of cvd. -when the arteries that carry blood to the heart muscle become blocked, the heart suffers damage known as coronary heart disease (chd). -cardio (cid:2) heart vascular (cid:2) blood vessels fatty streaks: accumulations of cholesterol and other lipids along the walls of the arteries. -plaque (plack): an accumulation of fatty deposits, smooth muscle cells, and fibrous connective tissue that develops in the artery walls in atherosclerosis. -plaque associated with atherosclerosis is known as atheromatous (ath- er-oh-ma-tus) plaque. -(see figure h16-1). -during adolescence, these fatty streaks may be- gin to accumulate fibrous connective tissue. -by early adulthood, the fibrous plaques may begin to calcify and become raised lesions, es- pecially in boys and young men. -as the lesions grow more numer- ous and enlarge, the heart disease rate begins to rise, most dramatically at about age 45 in men and 55 in women. -from this point on, arterial damage and blockage progress rapidly, and heart attacks and strokes threaten life. -in short, the consequences of ath- erosclerosis, which become apparent only in adulthood, have their beginnings in the first decades of life.9 atherosclerosis is not inevitable; people can grow old with rela- tively clear arteries. -early lesions may either progress or regress, de- pending on several factors, many of which reflect lifestyle behaviors. -smoking, for example, is strongly associated with the prevalence of fatty streaks and raised lesions, even in young adults. -figure h16-1 the formation of plaques in atherosclerosis 1 the coronary arteries deliver oxygen and nutrients to the heart muscle. -1 plaque 2 a healthy artery provides an open passage for the flow of blood. -2 3 plaques can begin to form in a person as young as 15. -3 when these arteries become blocked by plaque, the part of the muscle that they feed will die. -plaques form along the artery s inner wall, reducing blood flow. -clots can form, aggravating the problem. -blood cholesterol as blood cholesterol rises, atherosclerosis worsens. -cholesterol val- ues at birth are similar in all populations; differences emerge in early childhood. -standard values for cholesterol in children and adoles- cents (ages 2 to 18 years) are listed in table h16-1 (p. 588). -in general, blood cholesterol tends to rise as dietary saturated fat intakes increase. -blood cholesterol also correlates with childhood obesity, especially abdominal obesity.10 ldl cholesterol rises with obesity, and hdl declines. -these relationships are apparent throughout childhood, and their magnitude increases with age. -children who are both overweight and have high blood cho- lesterol are likely to have parents who develop heart disease early.11 for this reason, selective screening is recommended for children and adolescents whose parents (or grandparents) have heart disease; those whose parents have ele- vated blood cholesterol; and those whose fam- ily history is unavailable, especially if other risk factors are evident.12 because blood cholesterol in children is a good predictor of adult values, some experts recommend universal screening for all children, and particularly for those who are overweight, smoke, are sedentary, or con- sume diets high in saturated fat. -, n o i s i v i d l a c i t u e c a m r a h p a c e n e z f o y s e t r u o c ) h t o b ( d n a l g n e , e r i h s e h c early but not advanced atherosclerotic le- sions are reversible, making screening and edu- cation a high priority. -both those with family histories of heart disease and those with multi- ple risk factors need intervention. -children with the highest risks of developing heart disease are sedentary and obese, with high blood pressure and high blood cholesterol.13 in contrast, chil- dren with the lowest risks of heart disease are physically active and of normal weight, with low blood pressure and favorable lipid profiles. -routine pediatric care should identify these known risk factors and provide intervention when needed. -blood pressure pediatricians routinely monitor blood pressure in children and adolescents. -high blood pres- sure may signal an underlying disease or the early onset of hypertension. -hypertension accel- erates the development of atheroscerlosis.14 588 highlight 16 table h16-1 and adolescents cholesterol values for children table h16-2 guidelines and strategies for childrena american heart association dietary disease risk acceptable borderline high total cholesterol (mg/dl) (cid:3)170 170 199 (cid:4)200 ldl cholesterol (mg/dl) (cid:3)100 100 129 (cid:4)130 note: adult values appear in table 18-4 on p. 630. like atherosclerosis and high blood cholesterol, hypertension may develop in the first decades of life, especially among obese chil- dren, and worsen with time.15 children can control their hyperten- sion by participating in regular aerobic activity and by losing weight or maintaining their weight as they grow taller. -evidence is needed to clarify whether restricting sodium in children s and adolescent s diets lowers blood pressure. -physical activity research has also confirmed an association between blood lipids and physical activity in children, similar to that seen in adults. -physically active children have a better lipid profile and lower blood pressure than physically inactive children, and these posi- tive findings often persist into adulthood. -just as blood cholesterol and obesity track over the years, so does a youngster s level of physical activity. -those who are inac- tive now are likely to still be inactive years later. -similarly, those who are physically active now tend to remain so. -compared with inactive teens, those who are physically active weigh less, smoke less, eat a diet lower in saturated fats, and have better blood lipid profiles. -both obesity and blood cholesterol correlate with the in- active pastime of watching television. -the message is clear: phys- ical activity offers numerous health benefits, and children who are active today are most likely to be active for years to come. -dietary recommendations for children regardless of family history, experts agree that all children over age two should eat a variety of foods and maintain desirable weight (see table h16-2). -children (4 to 18 years of age) should receive at least 25 percent and no more than 35 percent of total energy from fat, less than 10 percent from saturated fat, and less than 300 milligrams of cholesterol per day.16 recommendations limiting fat and cholesterol are not intended for infants or children balance dietary kcalories with physical activity to maintain normal growth. -every day, engage in 60 minutes of moderate to vigorous play or phys- ical activity. -eat vegetables and fruits daily. -use fresh, frozen, and canned vegetables and fruits and serve at every meal; limit those with added fats, salt, and sugar. -limit juice intake (4 to 6 ounces per day for children 1 to 6 years of age, 8 to 12 ounces for children 7 to 18 years of age). -use vegetable oils (canola, soybean, olive, safflower, or other unsatu- rated oils) and soft margarines low in saturated fat and trans fatty acids instead of butter or most other animal fats in the diet. -choose whole-grain breads and cereals rather than refined products; read labels and make sure that whole grain is the first ingredient. -reduce the intake of sugar-sweetened beverages and foods. -consume low-fat and nonfat milk and milk products daily. -include 2 servings of fish per week, especially fatty fish such as broiled or baked salmon. -choose legumes and tofu in place of meat for some meals. -choose only lean cuts of meat and reduced-fat meat products; remove the skin from poultry. -use less salt, including salt from processed foods. -breads, breakfast cereals, and soups may be high in salt and/or sugar so read food labels and choose high-fiber, low-salt, low-sugar alternatives. -limit the intake of high-kcalorie add-ons such as gravy, alfredo sauce, cream sauce, cheese sauce, and hollandaise sauce. -serve age-appropriate portion sizes on appropriately sized plates and bowls. -a these guidelines are for children 3 years of age and older. -source: adapted from american heart association, samuel s. gidding, and coauthors, dietary recommendations for children and adolescents: a guide for practitioners, pediatrics 117 (2006): 544 559. under two years old. -infants and toddlers need a higher percent- age of fat to support their rapid growth. -moderation, not deprivation healthy children over age two can begin the transition to eating according to recommendations by eating fewer foods high in sat- urated fat and selecting more fruits and vegetables. -healthy meals can occasionally include moderate amounts of a child s fa- vorite foods, even if they are high in saturated fat such as french fries and ice cream. -a steady diet of offerings from some chil- dren s menus in restaurants such as chicken nuggets, hot dogs, and french fries, easily exceeds a prudent intake of saturated fat, trans fat, and kcalories, however, and invites both nutrient short- ages and weight gains.17 fortunately, most restaurants chains are changing children s menus to include steamed vegetables, fruit cups, and broiled or grilled poultry additions welcomed by busy parents who often dine out or purchase take-out foods. -other fatty foods, such as nuts, vegetable oils, and some vari- eties of fish such as light canned tuna or salmon, are important for childhood obesity and the early development of chronic diseases 589 their essential fatty acids. -low-fat milk and milk products also de- serve special attention in a child s diet for the needed calcium and other nutrients they supply.18 parents and caregivers play a key role in helping children es- tablish healthy eating habits. -balanced meals need to provide lean meat, poultry, fish, and legumes; fruits and vegetables; whole grains; and low-fat milk products. -such meals can provide enough energy and nutrients to support growth and maintain blood cholesterol within a healthy range. -pediatricians warn parents to avoid extremes. -although inten- tions may be good, excessive food restriction may create nutrient deficiencies and impair growth. -furthermore, parental control over eating may instigate battles and foster attitudes about foods that can lead to inappropriate eating behaviors. -diet first, drugs later experts agree that children with high blood cholesterol should first be treated with diet. -if blood cholesterol remains high in chil- dren ten years and older after 6 to 12 months of dietary interven- tion, then drugs may be necessary to lower blood cholesterol. -drugs can effectively lower blood cholesterol without interfering with adolescent growth or development.19 smoking even though the focus of this text is nutrition, another risk factor for heart disease that starts in childhood and carries over into adult- hood must also be addressed cigarette smoking. -each day 3000 children light up for the first time typically in grade school. -among high school students, almost two out of three have tried smoking, and one in five smokes regularly.20 approximately 80 per- cent of all adult smokers began smoking before the age of 18. of those teenagers who continue smoking, half will eventually die of smoking-related causes. -efforts to teach children about the dangers of smoking need to be aggressive. -children are not likely to consider the long-term health consequences of tobacco use. -they are more likely to be struck by the immediate health nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 16, then to highlights nutrition on the net. -get weight-loss tips for children and adolescents: www.shapedown.com y m a l a / y r a r b i l o t o h p l e d e i w e n i n a j cigarette smoking is the number one preventable cause of deaths. -consequences, such as shortness of breath when playing sports, or social consequences, such as having bad breath. -whatever the context, the message to all children and teens should be clear: don t start smoking. -if you ve already started, quit. -in conclusion, adult heart disease is a major pediatric problem. -with- out intervention, some 60 million children are destined to suffer its consequences within the next 30 years. -optimal prevention efforts focus on children, especially on those who are overweight.21 just as young children receive vaccinations against infectious diseases, they need screening for, and education about, chronic diseases. -many health education programs have been imple- mented in schools around the country. -these programs are most effective when they include education in the classroom, heart- healthy meals in the lunchroom, fitness activities on the play- ground, and parental involvement at home. -learn about nondietary approaches to weight loss from hugs international: www.hugs.com visit the nemours foundation: www.kidshealth.org find information on diabetes in children at the american diabetes association and juvenile diabetes research foun- dation: www.diabetes.org and www.jdrf.org 590 highlight 16 references 1.c. -l. ogden and coauthors, prevalence of overweight and obesity in the united states, 1999 2004, journal of the american medical association 295 (2006): 1549 1555; j. p. kaplan, c. t. liverman, and v. i. kraak, eds., preventing childhood obesity: health in the balance (washington, d.c.: national acade- mies press, 2005), pp. -1 20; m. l. cruz and coauthors, pediatric obesity and insulin resistance: chronic disease risk and implica- tions for treatment and prevention beyond body weight modification, annual review of nutrition 25 (2005): 435 468; t. lobstein, l. baur, and r. uauy, obesity in children and young people: a crisis in public health, obesity reviews 5 (2004): 4 85. -2.m. -e. pavkov and coauthors, effect of youth- onset type 2 diabetes mellitus on incidence of end-stage renal disease and mortality in young and middle-aged pima indians, journal of the american medical association 296 (2006): 421 426. -3.kaplan, liverman, and kraak, 2005. -4.cruz and coauthors, 2005; m. kohn and m. booth, the worldwide epidemic of obesity in adolescents, adolescent medicine 14 (2003): 1 9; l. s. lieberman, dietary, evolu- tionary, and modernizing influences on the prevalence of type 2 diabetes, annual review of nutrition 23 (2003): 345 377; committee on nutrition, american academy of pedi- atrics, prevention of pediatric overweight and obesity, pediatrics 112 (2003): 424 430. -5. a. must, does overweight in childhood have an impact on adult health? -nutrition reviews 61 (2003): 139 142; d. s. freedman, cluster- ing of coronary heart disease risk factors among obese children, journal of pediatric endocrinology and metabolism 15 (2002): 1099 1108. -6. t. s. hannon, g. rao, and s. a. arslanian, childhood obesity and type 2 diabetes melli- tus, pediatrics 116 (2005): 473 480; cruz and coauthors, 2005. -7. hannon, rao, and arslanian, 2005; cruz and coauthors, 2005. -8. g. s. boyd and coauthors, effect of obesity and high blood pressure on plasma lipid levels in children and adolescents, pediatrics 116 (2005): 473 480; r. kohen-avramoglu, a. theriault, and k. adeli, emergence of the metabolic syndrome in childhood: an epi- demiological overview and mechanistic link to dyslipidemia, clinical biochemistry 36 (2003): 413 420. -9. s. li and coauthors, childhood cardiovascular risk factors and carotid vascular changes in adulthood: the bogalusa heart study, journal of the american medical association 290 (2003): 2271 2276; k. b. keller and l. lemberg, obesity and the metabolic syndrome, ameri- can journal of clinical care 12 (2003): 167 170. -10. o. fiedland and coauthors, obesity and lipid profiles in children and adolescents, journal of pediatric endocrinology and metabolism 15 (2002): 1011 1016; t. dwyer and coauthors, syndrome x in 8-y-old australian children: stronger associations with current body fatness than with infant size or growth, international journal of obesity and related metabolic disorders 26 (2002): 1301 1309. -11. b. glowinska, m. urban, and a. koput, cardiovascular risk factors in children with obesity, hypertension and diabetes: lipopro- tein (a) levels and body mass index correlate with family history of cardiovascular disease, european journal of pediatrics 161 (2002): 511 518. -12. a. wiegman and coauthors, family history and cardiovascular risk in familial hypercho- lesterolemia: data in more than 1000 chil- dren, circulation 107 (2003): 1473 1478. -13. v. n. muratova and coauthors, the relation of obesity to cardiovascular risk factors among children: the cardiac project, west virginia medical journal 98 (2002): 263 267. -14. national high blood pressure education program working group on high blood pressure in children and adolescents, the fourth report on the diagnosis, evaluation, and treatment of high blood pressure in children and adolescents, pediatrics 114 (2004): 555s 576s. -15. dwyer and coauthors, 2002. -16. committee on dietary reference intakes, dietary reference intakes for energy, carbohy- drate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (washington, d.c.: national academies press, 2005), pp. -769 879. -17. j. hurley and b. liebman, kids cuisine: what would you like with your fries? -nutrition action healthletter 31 (2004): 12 15. -18. f. r. greer, n. f. krebs, and the committee on nutrition, american academy of pediatrics, optimizing bone health and calcium intakes of infants, children, and adolescents, pedi- atrics 117 (2006): 578 585. -19. s. de jongh and coauthors, efficacy and safety of statin therapy in children with familial hypercholesterolemia: a randomized, double- blind, placebo-controlled trial with simvas- tatin, circulation 106 (2002): 2231 2237. -20. centers for disease control and prevention, youth tobacco surveillance united states, 2001 2002, morbidity and mortality weekly report 55 (2006): entire supplement. -21. committee on nutrition, american academy of pediatrics, prevention of pediatric over- weight and obesity, obesity 112 (2003): 424 430. this page intentionally left blank still images/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow how to: practice problems nutrition portfolio journal nutrition in your life take a moment to envision yourself 20, 40, or even 60 years from now. -are you physically fit and healthy? -can you see yourself walking on the beach with friends or tossing a ball with children? -are you able to climb stairs and carry your own groceries? -importantly, are you enjoying life? -if you re lucky, you will grow old with good health, but much of that depends on your actions today and every day from now until then. -making nutritious foods and physical activities a priority in your life can help bring rewards of continued health and enjoyment in later life. -life cycle nutrition: adulthood and the later years wise food choices, made throughout adulthood, can support a person s ability to meet physical, emotional, and mental challenges and to enjoy freedom from disease. -two goals motivate adults to pay attention to their diets: promoting health and slowing aging. -much of this text has focused on nutrition to support health, and chapter 18 features prevention of chronic diseases such as cancer and heart disease. -this chapter focuses on aging and the nutrition needs of older adults. -the u.s. population is growing older. -the majority is now middle-aged, and the ratio of old people to young is increasing, as figure 17-1 (p. 594) shows. -in 1900, only 1 out of 25 people was 65 or older. -in 2000, 1 out of 8 had reached age 65. projections for 2030 are 1 out of 5. our society uses the arbitrary age of 65 years to define the transition point between middle age and old age, but growing old happens day by day, with changes occurring gradually over time. -since 1950 the popula- tion of those over 65 has almost tripled. -remarkably, the fastest-growing age group has been people over 85 years; since 1950 their numbers have increased sevenfold. -the number of people in the united states age 100 or older doubled in the last decade. -similar trends are occurring in popula- tions worldwide.1 life expectancy in the united states for white women is 81 years and for black women, 76 years; for white men, it is 75 years and for black men, 69 years all record highs and much higher than the average life ex- pectancy of 47 years in 1900.2 women who live to 80 can expect to survive an additional 9 years, on average; men, an additional 7 years. -advances in medical science antibiotics and other treatments are largely respon- sible for almost doubling the life expectancy in the 20th century. -improved nutrition and an abundant food supply have also contributed to lengthen- ing life expectancy. -the life span has not lengthened as dramatically; hu- man longevity appears to have an upper limit. -the potential human life c h a p t e r 17 chapter outline nutrition and longevity observa- tion of older adults manipulation of diet the aging process physiological changes other changes energy and nutrient needs of older adults water energy and energy nutrients vitamins and minerals nutrient supplements nutrition-related concerns of older adults vision arthritis the aging brain food choices and eating habits of older adults food assistance programs meals for singles highlight 17 nutrient-drug interactions life expectancy: the average number of years lived by people in a given society. -life span: the maximum number of years of life attainable by a member of a species. -span is currently 130 years. -with recent advances in medical technology longevity: long duration of life. -593 594 chapter 17 figure 17-1 the aging of the u.s. population in general, the percentage of older people in the population has increased over the decades whereas the percentage of younger people has decreased. -key: 65 years 45 64 years 25 44 years 15 24 years >15 years 4.1 13.7 28.1 19.6 4.3 4.7 5.4 6.8 8.1 9.2 9.9 11.3 12.6 12.4 19.8 20.3 20.1 20.6 19.6 18.6 22.0 14.6 16.1 17.5 29.2 29.6 29.5 30.1 30.0 26.2 23.6 27.7 32.5 19.7 17.7 18.3 13.4 17.4 18.2 14.7 18.8 14.8 30.2 13.9 34.5 32.1 31.8 29.4 25.0 26.9 31.1 28.5 22.6 21.5 21.4 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 source: u.s. census bureau, decennial census of population, 1900 to 2000. and genetic knowledge, however, researchers may one day be able to ex- tend the life span even further by slowing, or perhaps preventing, aging and its accompanying diseases.3 nutrition and longevity research in the field of aging is active and difficult. -researchers are challenged by the diversity of older adults. -when older adults experience health problems, it is hard to know whether to attribute these problems to genetics, aging, or other envi- ronmental factors such as nutrition. -the idea that nutrition can influence the aging process is particularly appealing because people can control and change their eat- ing habits. -the questions being asked include: to what extent is aging inevitable, and can it be slowed through changes in lifestyle and environment? -what role does nutrition play in the aging process, and what role can it play in slowing aging? -with respect to the first question, it seems that aging is an inevitable, natural process, programmed into the genes at conception.4 people can, however, slow the process within genetic limits by adopting healthy lifestyle habits such as eating nu- tritious food and engaging in physical activity. -in fact, an estimated 70 to 80 per- cent of the average person s life expectancy may depend on individual health- related behaviors; genes determine the remaining 20 to 30 percent.5 with respect to the second question, good nutrition helps to maintain a healthy body and can therefore ease the aging process in many significant ways. -clearly, nutrition can improve the quality of life in the later years. -quality of life: a person s perceived physical and mental well-being. -life cycle nutrition: adulthood and the later years 595 observation of older adults the strategies adults use to meet the two goals mentioned at the start of this chap- ter promoting health and slowing aging are actually very much the same. -what to eat, when to sleep, how physically active to be, and other lifestyle choices greatly influence both physical health and the aging process. -healthy habits a person s physiological age reflects his or her health status and may or may not reflect the person s chronological age. -quite simply, some people seem younger, and others older, than their years. -six lifestyle behaviors seem to have the greatest influence on people s health and therefore on their physiologi- cal age: sleeping regularly and adequately eating well-balanced meals, including breakfast, regularly engaging in physical activity regularly not smoking not using alcohol, or using it in moderation maintaining a healthy body weight over the years, the effects of these lifestyle choices accumulate that is, people who follow most of these practices live longer and have fewer disabilities as they age. -they are in better health, even when older in chronological age, than people who do not adopt these behaviors. -even though people cannot change their birth dates, they may be able to add years to, and enhance the quality of, their lives. -physical activity seems to be most influential in preventing or slowing the many changes that define a stereotypical old person. -after all, many of the physical limitations that accompany aging occur because people become inactive, not because they be- come older. -physical activity the many remarkable benefits of regular physical activity out- lined in chapter 14 are not limited to the young. -compared with those who are in- active, older adults who are active weigh less; have greater flexibility, more endurance, better balance, and better health; and live longer.6 they reap additional benefits from various activities as well: aerobic activities improve cardiorespiratory endurance, blood pressure, and blood lipid concentrations; moderate endurance ac- tivities improve the quality of sleep; and strength training improves posture and mobility. -in fact, regular physical activity is the most powerful predictor of a person s mobility in the later years. -physical activity also increases blood flow to the brain, thereby preserving mental ability, alleviating depression, supporting independence, and improving quality of life.7 dietary guidelines for americans 2005 older adults should participate in regular physical activity to reduce the functional declines associated with aging and to achieve the other bene- fits of physical activity identified for all adults. -muscle mass and muscle strength tend to decline with aging, making older peo- ple vulnerable to falls and immobility. -falls are a major cause of fear, injury, dis- ability, and even death among older adults.8 many lose their independence as a result of falls. -regular physical activity tones, firms, and strengthens muscles, help- ing to improve confidence, reduce the risk of falling, and lessen the risk of injury should a fall occur. -even without a fall, older adults may become so weak that they can no longer perform life s daily tasks, such as climbing stairs, carrying packages, and opening jars. -by improving muscle strength, which allows a person to perform these tasks, strength training helps to maintain independence. -even in frail, elderly people over physiological age: a person s age as estimated from her or his body s health and probable life expectancy. -chronological age: a person s age in years from his or her date of birth. -596 chapter 17 regular physical activity promotes a healthy, independent lifestyle. -85 years of age, strength training not only improves balance, muscle strength, and mobility, but it also increases energy expenditure and energy intake, thereby en- hancing nutrient intakes. -this finding highlights another reason to be physically active: a person spending energy can afford to eat more food and thus receives more nutrients. -people who are committed to an ongoing fitness program can ben- efit from higher energy and nutrient intakes and still maintain their body weights. -ideally, physical activity should be part of each day s schedule and should be in- tense enough to prevent muscle atrophy and to speed up the heartbeat and respi- ration rate. -although aging reduces both speed and endurance to some degree, older adults can still train and achieve exceptional performances. -healthy older adults who have not been active can ease into a suitable routine. -they can start by walking short distances until they are walking at least 10 minutes continuously and then gradually increase their distance to a 30- to 45-minute workout at least 5 days a week. -table 17-1 provides exercise guidelines for seniors. -people with med- ical conditions should check with a physician before beginning an exercise routine, as should sedentary men over 40 and sedentary women over 50 who want to par- ticipate in a vigorous program. -s i b r o c / s e n o j . -w . -r manipulation of diet in their efforts to understand longevity, researchers have not only observed people, but they have also manipulated influencing factors, such as diet, in animals. -this research has given rise to some interesting and suggestive findings. -energy restriction in animals animals live longer and have fewer age-related diseases when their energy intakes are restricted. -these life-prolonging benefits be- come evident when the diet provides enough food to prevent malnutrition and an energy intake of about 70 percent of normal. -exactly how energy restriction pro- longs life remains largely unexplained, although gene activity appears to play a key role. -the genetic activity of old mice differs from that of young mice, with some genes becoming more active with age and others less active. -with an energy- restricted diet, many of the genetic activities of older mice revert to those of younger mice. -these slow-aging genetic changes are apparent in as little as one month on an energy-restricted, but still nutritionally adequate, diet. -table 17-1 exercise guidelines for older adults endurance strength balance flexibility examples start easy s e g a m i r e t i p u j / c s i d o t o h p / e s s a n a m f f o e g s e g a m i r e t i p u j / e e r f k c o t s t i s e g a m i r e t i p u j / e e r f k c o t s t i s e g a m i r e t i p u j / k c o t s k n i h t / e l p p a h c n o r be active 5 minutes on most or all days. -using 0- to 2-pound weights, do 1 set of 8 repeti- tions twice a week. -hold onto table or chair with one hand, then with one finger. -hold stretch 10 seconds; do each stretch 3 times. -progress gradually to goal be active 30 minutes (minimum) on most or all days. -increase weight as able; do 2 sets of 8 15 repetitions twice a week. -do not hold onto table or chair; then close eyes. -hold stretch 30 seconds; do each stretch 5 times. -cautions and comments stop if you are breathing so hard you can t talk or if you feel dizziness or chest pain. -breathe out as you contract and in as you relax (do not hold breath); use smooth, steady movements. -incorporate balance tech- niques with strength exercises as you progress. -stretch after strength and endurance exercises for 20 minutes, 3 times a week; use slow, steady movements; bend joints slightly. -source: exercise: a guide from the national institute on aging, www.nia.nih.gov. -life cycle nutrition: adulthood and the later years 597 the consequences of energy restriction in animals include a delay in the onset, or prevention, of diseases such as atherosclerosis; prolonged growth and develop- ment; and improved blood glucose, insulin sensitivity, and blood lipids. -in addi- tion, energy metabolism slows and body temperature drops indications of a reduced rate of oxygen consumption. -as highlight 11 explained, the use of oxygen during energy metabolism produces free radicals, which have been implicated in the aging process. -restricting energy intake in animals not only produces fewer free radicals, but also increases antioxidant activity and enhances dna repair. -reduc- ing oxidative stress may at least partially explain how restricting energy intake lengthens life expectancy.9 interestingly, longevity appears to depend on restricting energy intake and not on the amount of body fat. -genetically obese rats live longer when given a re- stricted diet even though their body fat is similar to that of other rats allowed to eat freely. -energy restriction in human beings research on a variety of animals con- firms the relationship between energy restriction and longevity. -applying the results of animal studies to human beings is problematic, however, and conducting studies on human beings raises numerous questions beginning with how to define energy restriction.10 does it mean eating less or just weighing less? -is it less than you want or less than the average? -does eating less have to result in weight loss? -does it mat- ter whether weight loss results from more exercise or from less food? -or whether weight loss is intentional or unintentional? -answers await research. -extreme starvation to extend life, like any extreme, is rarely, if ever, worth the price. -moderation, on the other hand, may be valuable. -many of the physiological responses to energy restriction seen in animals also occur in people whose intakes are moderately restricted. -when people cut back on their usual energy intake by 10 to 20 percent, body weight, body fat, and blood pressure drop, and blood lipids and insulin response improve favorable changes for preventing chronic dis- eases.11 some research suggests that fasting on alternative days may provide simi- lar benefits.12 the reduction in oxidative damage that occurs with energy restriction in animals also occurs in people whose diets include antioxidant nutri- ents and phytochemicals. -diets, such as the mediterranean diet, which include an abundance of fruits, vegetables, olive oil, and red wine with their array of antiox- idants and phytochemicals support good health and long life.13 clearly, nutri- tional adequacy is essential to living a long and healthy life. -in summary life expectancy in the united states increased dramatically in the 20th cen- tury. -factors that enhance longevity include limited or no alcohol use, regular balanced meals, weight control, adequate sleep, abstinence from smoking, and regular physical activity. -energy restriction in animals seems to lengthen their lives. -whether such dietary intervention in human beings is beneficial remains unknown. -at the very least, nutrition especially when combined with regular physical activity can influence aging and longevity in human beings by supporting good health and preventing disease. -kcalorie-restricted research has been con- ducted on various species, including mice, rats, rhesus monkeys, cynomolgus mon- keys, spiders, and fish. -for perspective, a person with a usual energy intake of 2000 kcalories might cut back to 1600 to 1800 kcalories. -the aging process as people get older, each person becomes less and less like anyone else. -the older people are, the more time has elapsed for such factors as nutrition, genetics, physi- cal activity, and everyday stress to influence physical and psychological aging. -stress promotes the early onset of age-related diseases.14 both physical stres- sors (such as alcohol abuse, other drug abuse, smoking, pain, and illness) and stress: any threat to a person s well-being; a demand placed on the body to adapt. -stressors: environmental elements, physical or psychological, that cause stress. -598 chapter 17 stress response: the body s response to stress, mediated by both nerves and hormones. -sarcopenia (sar-koh-pee-nee-ah): loss of skeletal muscle mass, strength, and quality. -sarco = flesh penia = loss or lack psychological stressors (such as exams, divorce, moving, and the death of a loved one) elicit the body s stress response. -the body responds to such stressors with an elaborate series of physiological steps, as the nervous and hormonal systems bring about defensive readiness in every body part. -these effects favor physical action the classic fight-or-flight response. -prolonged or severe stress can drain the body of its reserves and leave it weakened, aged, and vulnerable to illness, especially if phys- ical action is not taken. -as people age, they lose their ability to adapt to both exter- nal and internal disturbances. -when disease strikes, the reduced ability to adapt makes the aging individual more vulnerable to death than a younger person. -because the stress response is mediated by hormones, it differs between men and women.15 the fight-or-flight response may be more typical of men than of women. -women s reactions to stress more typically follow a pattern of tend-and- befriend. -16 women tend by nurturing and protecting themselves and their chil- dren. -these actions promote safety and reduce stress. -women befriend by creating and maintaining a social group that can help in the process. -highlight 11 described the oxidative stresses and cellular damage that occur when free radicals exceed the body s ability to defend itself. -increased free-radical activity and decreased antioxidant protection are common features of aging and antioxidants seem to help slow the aging process.17 such findings seem to suggest that the fountain of youth may actually be a cornucopia of fruits and vegetables rich in antioxidants. -(return to highlight 11 for more details on the antioxidant action of fruits and vegetables in defending against oxidative stress.) -physiological changes as aging progresses, inevitable changes in each of the body s organs contribute to the body s declining function. -these physiological changes influence nutrition sta- tus, just as growth and development do in the earlier stages of the life cycle. -body weight two-thirds of older adults in the united states are now considered overweight or obese. -chapter 8 presented the many health problems that accom- pany obesity and the bmi guidelines for a healthy body weight (18.5 to 24.9). -these guidelines apply to all adults, regardless of age, but they may be too restrictive for older adults. -the importance of body weight in defending against chronic diseases differs for older adults. -being moderately overweight may not be harmful. -for adults over 65, health risks do not become apparent until bmi reaches at least 27 and the relationship tends to diminish with age until it disappears by age 75. older adults who are obese, however, face serious medical complications and can significantly improve their quality of life with weight loss.18 for some older adults, a low body weight may be more detrimental than a high one. -low body weight often reflects malnutrition and the trauma associated with a fall. -many older adults experience unintentional weight loss, in large part because of an inadequate food intake. -without adequate nutrient reserves, an underweight person may be unprepared to fight against diseases. -for underweight people, even a slight weight loss (5 percent) increases the likelihood of disease and premature death, making every meal a life-saving event. -body composition in general, older people tend to lose bone and muscle and gain body fat. -many of these changes occur because some hormones that regulate appetite and metabolism become less active with age, whereas others become more active.19* loss of muscle, known as sarcopenia, can be significant in the later years, and its consequences can be quite dramatic (see figure 17-2).20 as muscles di- * causes of diminished appetite in older adults include increased cholecystokinin, leptin, and cytokines and decreased ghrelin and testosterone. -additional examples of hormones that change with age include growth hormone and androgens, which decline with advancing age, thus contributing to the decrease in lean body mass, and prolactin, which increases with age, helping to maintain body fat. -insulin sensi- tivity also diminishes as people grow older, most likely because of increases in body fat and decreases in physical activity. -life cycle nutrition: adulthood and the later years 599 figure 17-2 sarcopenia ) h t o b ( s n a v e m a i l l i w . -r d f o y s e t r u o c these cross sections of two women s thighs may appear to be about the same size from the outside, but the 20-year-old woman s thigh (left) is dense with muscle tissue. -the 64-year-old woman s thigh (right) has lost muscle and gained fat, changes that may be largely preventable with strength-building physical activities. -minish and weaken, people lose the ability to move and maintain balance making falls likely. -the limitations that accompany the loss of muscle mass and strength play a key role in the diminishing health that often accompanies ag- ing.21 optimal nutrition and regular physical activity can help maintain mus- cle mass and strength and minimize the changes in body composition associated with aging.22 risk factors for sarcopenia include weight loss, little physical activity, and ciga- rette smoking.23 obesity and the inflammation that accompanies it may also con- tribute to sarcopenia.24 immune system changes in the immune system also bring declining function with age. -in addition, the immune system is compromised by nutrient deficiencies. -thus the combination of age and malnutrition makes older people vulnerable to in- fectious diseases. -adding insult to injury, antibiotics often are not effective against infections in people with compromised immune systems. -consequently, infectious diseases are a major cause of death in older adults. -older adults may improve their immune system responses by exercising regularly. -gi tract in the gi tract, the intestinal wall loses strength and elasticity with age, and gi hormone secretions change. -all of these actions slow motility. -constipation is much more common in the elderly than in the young. -changes in gi hormone se- cretions also diminish appetite, leading to decreased energy intake and weight loss.25 atrophic gastritis, a condition that affects almost one-third of those over 60, is characterized by an inflamed stomach, bacterial overgrowth, and a lack of hy- drochloric acid and intrinsic factor. -all of these can impair the digestion and ab- sorption of nutrients, most notably, vitamin b12, but also biotin, folate, calcium, iron, and zinc. -difficulty in swallowing, medically known as dysphagia, occurs in all age groups, but especially in the elderly. -being unable to swallow a mouthful of food can be scary, painful, and dangerous. -even swallowing liquids can be a problem for some people. -consequently, the person may eat less food and drink fewer bev- erages, resulting in weight loss, malnutrition, and dehydration. -dietary interven- tion for dysphagia is highly individualized based on the person s abilities and tolerances. -the diet typically provides moist, soft-textured, tender-cooked, or pureed foods and thickened liquids. -consequences of atrophic gastritis: inflamed stomach increased bacterial growth reduced hydrochloric acid reduced intrinsic factor increased risk of nutrient deficiencies, notably of vitamin b12 tooth loss regular dental care over a lifetime protects against tooth loss and gum disease, which are common in old age. -these conditions make chewing difficult or dysphagia (dis-fay-jah): difficulty in swallowing. -600 chapter 17 the medical term for lack of teeth is eden- tulous (ee-dent-you-lus). -e = without dens = teeth conditions requiring dental care: dry mouth eating difficulty no dental care within two years tooth or mouth pain altered food selections lesions, sores, or lumps in mouth shared meals can brighten the day and enhance the appetite. -painful. -dentures, even when they fit properly, are less effective than natural teeth, and inefficient chewing can cause choking. -people with tooth loss, gum disease, and ill-fitting dentures tend to limit their food selections to soft foods. -if foods such as corn on the cob, apples, and hard rolls are replaced by creamed corn, applesauce, and rice, then nutrition status may not be greatly affected. -how- ever, when food groups are eliminated and variety is limited, poor nutrition fol- lows. -people without teeth typically eat fewer fruits and vegetables and have less variety in their diets.26 consequently, they have low intakes of fiber and vitamins, which exacerbates their dental and overall health problems.27 to determine whether a visit to the dentist is needed, an older adult can check the conditions listed in the margin. -sensory losses and other physical problems sensory losses and other phys- ical problems can also interfere with an older person s ability to obtain adequate nourishment. -failing eyesight, for example, can make driving to the grocery store impossible and shopping for food a frustrating experience. -it may become so dif- ficult to read food labels and count money that the person doesn t buy needed foods. -carrying bags of groceries may be an unmanageable task. -similarly, a per- son with limited mobility may find cooking and cleaning up too hard to do. -not too surprisingly, the prevalence of undernutrition is high among those who are homebound. -sensory losses can also interfere with a person s ability or willingness to eat. -taste and smell sensitivities tend to diminish with age and may make eating less enjoyable. -if a person eats less, then weight loss and nutrient deficiencies may fol- low. -loss of vision and hearing may contribute to social isolation, and eating alone may lead to poor intake. -other changes in addition to the physiological changes that accompany aging, adults change in many other ways that influence their nutrition status.28 psychological, economic, and social factors play big roles in a person s ability and willingness to eat. -psychological changes although not an inevitable component of aging, de- pression is common among older adults.29 depressed people, even those without disabilities, lose their ability to perform simple physical tasks. -they frequently lose their appetite and the motivation to cook or even to eat. -an overwhelming sense of grief and sadness at the death of a spouse, friend, or family member may leave a person, especially an elderly person, feeling powerless to overcome de- pression. -when a person is suffering the heartache and loneliness of bereave- ment, cooking meals may not seem worthwhile. -the support and companionship of family and friends, especially at mealtimes, can help overcome depression and enhance appetite. -economic changes overall, older adults today have higher incomes than their cohorts of previous generations. -still, 10 percent of the people over age 65 live in poverty. -factors such as living arrangements and income make significant differ- ences in the food choices, eating habits, and nutrition status of older adults, espe- cially those over age 80. people of low socioeconomic means are likely to have inadequate food and nutrient intakes. -only about one-third of the needy elderly receive assistance from federal programs. -social changes malnutrition among older adults is most common in hospi- tals and nursing homes.30 in the community, malnutrition is most likely to oc- cur among those living alone, especially men; those with the least education; those living in federally funded housing (an indicator of low income); and those who have recently experienced a change in lifestyle. -adults who live alone do not necessarily make poor food choices, but they often consume too little food. -loneliness is directly related to nutritional inadequacies, especially of energy intake. -s e g a m i y t t e g / e n o t s / s a m o h t b o b life cycle nutrition: adulthood and the later years 601 in summary many changes that accompany aging can impair nutrition status. -among physiological changes, hormone activity alters body composition, immune system changes raise the risk of infections, atrophic gastritis interferes with di- gestion and absorption, and tooth loss limits food choices. -psychological changes such as depression, economic changes such as loss of income, and so- cial changes such as loneliness contribute to poor food intake. -energy and nutrient needs of older adults knowledge about the nutrient needs and nutrition status of older adults has grown considerably in recent years. -the dietary reference intakes (dri) cluster people over 50 into two age categories one group of 51 to 70 years and one of 71 and older. -in- creasingly, research is showing that the nutrition needs of people 50 to 70 years old differ from those of people over 70. setting standards for older people is difficult because individual differences be- come more pronounced as people grow older.31 people start out with different ge- netic predispositions and ways of handling nutrients, and the effects of these differences become magnified with years of unique dietary habits. -for example, one person may tend to omit fruits and vegetables from his diet, and by the time he is old, he may have a set of nutrition problems associated with a lack of fiber and antioxidants. -another person may have omitted milk and milk products all her life her nutrition problems may be related to a lack of calcium. -also, as people age, they suffer different chronic diseases and take various medicines both of which will affect nutrient needs. -for all of these reasons, researchers have difficulty even defining healthy aging, a prerequisite to developing recommendations to meet the needs of practically all healthy persons. -the following discussion gives special attention to the nutrients of greatest concern. -water despite real fluid needs, many older people do not seem to feel thirsty or notice mouth dryness. -many nursing home employees say it is hard to persuade their eld- erly clients to drink enough water and fruit juices. -older adults may find it difficult and bothersome to get a drink or to get to a bathroom. -those who have lost bladder control may be afraid to drink too much water. -dehydration is a risk for older adults.32 total body water decreases as people age, so even mild stresses such as fever or hot weather can precipitate rapid dehy- dration in older adults. -dehydrated older adults seem to be more susceptible to uri- nary tract infections, pneumonia, pressure ulcers, and confusion and disorienta- tion. -to prevent dehydration, older adults need to drink at least six glasses of water a day. -energy and energy nutrients on average, energy needs decline an estimated 5 percent per decade. -one reason is that people usually reduce their physical activity as they age, although they need not do so. -another reason is that basal metabolic rate declines 1 to 2 percent per decade in part because lean body mass and thyroid hormones diminish.33 the lower energy expenditure of older adults means that they need to eat less food to maintain their weights. -accordingly, the estimated energy requirements for adults decrease steadily after age 19, as the how to on p. 602 explains. -k c o t s r e p u s / o m o k i z e m a w k growing old can be enjoyable for people who take care of their health and live each day fully. -beverage recommendation for adults 51+ yr: men: 13 c/day women: 9 c/day when using the tables in appendix f to estimate energy requirements: men: subtract 10 kcal/day for each year of age above 19 women: subtract 7 kcal/day for each year of age above 19 pressure ulcers: damage to the skin and underlying tissues as a result of compression and poor circulation; commonly seen in people who are bedridden or chairbound. -602 chapter 17 how to estimate energy requirements for older adults the how to on p. 257 described how to estimate the energy requirements for adults using an equation that accounts for age, physical activity, weight, and height. -alter- natively, energy requirements for older adults can be guesstimated by using the values listed in the tables in appendix f for adults 30 years of age and subtracting 7 kcalories for women and 10 kcalories for men per day for each year over 30. for example, table f-4 lists 2556 kcalories per day for a woman who is 5 feet 5 inches tall, weighs 150 pounds, and has a low activ- ity level. -to estimate the energy requirements of a similar 50-year-old woman, subtract 7 kcalories per day for each year over 30: 50 (cid:2) 30 (cid:3) 20 yr 20 yr (cid:4) 7 kcal/day (cid:3) 140 kcal/day 2556 kcal/day (at age 30) (cid:2) 140 kcal/day (cid:3) 2416 kcal/day (at age 50) similarly, using table f-5 to estimate the energy requirements of a sedentary 65-year- old man who is 5 feet 11 inches tall and weighs 250 pounds, subtract 10 kcalories per day for each year over 30: 65 (cid:2) 30 (cid:3) 35 yr 35 yr (cid:4) 10 kcal/day (cid:3) 350 kcal/day 3088 kcal/day (at age 30) (cid:2) 350 kcal/day (cid:3) 2738 kcal/day (at age 65) (adults between the ages of 19 and 30 can also use the values listed in the tables in appendix f by adding 7 kcalories for women and 10 kcalories for men per day for each year below 30.) -to practice estimating energy requirements for older adults, log on to www.thomsonedu.com/login, go to chapter 17, then go to how to. -on limited energy allowances, people must select mostly nutrient-dense foods. -there is little leeway for added sugars, solid fats, or alcohol. -the usda food guide (pp. -41 47) offers a dietary framework for adults of all ages. -protein because energy needs decrease, protein must be obtained from low-kcalorie sources of high-quality protein, such as lean meats, poultry, fish, and eggs; fat-free and low-fat milk products; and legumes. -protein is especially important for the eld- erly to support a healthy immune system, prevent muscle wasting, and optimize bone mass. -underweight or malnourished older adults need protein- and energy-dense snacks such as hard-boiled eggs, tuna fish and crackers, peanut butter on wheat toast, and hearty soups. -drinking liquid nutritional formulas between meals can also boost energy and nutrient intakes.34 importantly, the diet should provide en- joyment as well as nutrients.35 carbohydrate and fiber as always, abundant carbohydrate is needed to pro- tect protein from being used as an energy source. -sources of complex carbohydrates such as legumes, vegetables, whole grains, and fruits are also rich in fiber and essen- tial vitamins and minerals. -average fiber intakes among older adults are lower than current recommendations (14 grams per 1000 kcalories).36 eating high-fiber foods and drinking water can alleviate constipation a condition common among older adults, especially nursing home residents. -physical inactivity and medications also contribute to the high incidence of constipation. -fat as is true for people of all ages, fat intake needs to be moderate in the diets of most older adults enough to enhance flavors and provide valuable nutrients, but not so much as to raise the risks of cancer, atherosclerosis, and other degenerative diseases. -this recommendation should not be taken too far; limiting fat too severely may lead to nutrient deficiencies and weight loss two problems that carry greater health risks in the elderly than overweight. -vitamins and minerals most people can achieve adequate vitamin and mineral intakes simply by includ- ing foods from all food groups in their diets, but older adults often omit fruits and vegetables. -similarly, few older adults consume the recommended amounts of milk or milk products. -vitamin b12 an estimated 10 to 30 percent of adults over 50 have atrophic gastri- tis. -as chapter 10 explained, people with atrophic gastritis are particularly vul- nerable to vitamin b12 deficiency. -the bacterial overgrowth that accompanies this condition uses up the vitamin, and without hydrochloric acid and intrinsic factor, digestion and absorption of vitamin b12 are inefficient. -given the poor cognition, anemia, and devastating neurological effects associated with a vitamin b12 defi- reminder: atrophic gastritis is a chronic inflammation of the stomach characterized by inadequate hydrochloric acid and intrinsic factor two key players in vitamin b12 absorption. -life cycle nutrition: adulthood and the later years 603 t i d e o t o h p / e t a c n o s u g r e f n e e l r y m taking time to nourish your body well is a gift you give yourself. -ciency, an adequate intake is imperative.37 the rda for older adults is the same as for younger adults, but with the added suggestion to obtain most of a day s intake from vitamin b12 fortified foods and supplements.38 the bioavailability of vitamin b12 from these sources is better than from foods. -dietary guidelines for americans 2005 people over age 50 should consume vitamin b12 from fortified foods or supplements. -vitamin d vitamin d deficiency is a problem among older adults. -only vitamin d fortified milk provides significant vitamin d, and many older adults drink little or no milk. -further compromising the vitamin d status of many older people, espe- cially those in nursing homes, is their limited exposure to sunlight. -finally, aging re- duces the skin s capacity to make vitamin d and the kidneys ability to convert it to its active form. -not only are older adults not getting enough vitamin d, but they may actually need more to improve both muscle and bone strength.39 to prevent bone loss and to maintain vitamin d status, especially in those who engage in min- imal outdoor activity, adults 51 to 70 years old need 10 micrograms daily, and those over 70 need 15 micrograms.40 dietary guidelines for americans 2005 older adults should consume extra vitamin d from vitamin d-fortified foods and/or supplements. -calcium both chapter 12 and highlight 12 emphasized the importance of abun- dant dietary calcium throughout life, especially for women after menopause, to pro- tect against osteoporosis. -the dri committee recommends 1200 milligrams of calcium daily, but the calcium intakes of older people in the united states are well below recommendations.41 some older adults avoid milk and milk products because they dislike these foods or associate them with stomach discomfort. -simple solutions include using calcium-fortified juices, adding powdered milk to recipes, and taking supplements. -chapter 12 offered many other strategies for including nonmilk sources of calcium for those who do not drink milk. -iron the iron needs of men remain unchanged throughout adulthood. -for women, iron needs decrease substantially when blood loss through menstruation ceases. -consequently, iron-deficiency anemia is less common in older adults than in younger people. -in fact, elevated iron stores are more likely than deficiency in older people, especially those who take iron supplements, eat red meat regularly, and in- clude vitamin c rich fruits in their daily diet.42 nevertheless, iron deficiency may develop in older adults, especially when their food energy intakes are low. -aside from diet, two other factors may lead to iron de- ficiency in older people: chronic blood loss from diseases and medicines and poor iron absorption due to reduced stomach acid secretion and antacid use. -iron defi- ciency impairs immunity and leaves older adults vulnerable to infectious dis- eases.43 anyone concerned with older people s nutrition should keep these possibilities in mind. -nutrient supplements people judge for themselves how to manage their nutrition, and more than half of older adults turn to dietary supplements.44 when recommended by a physician or 604 chapter 17 registered dietitian, vitamin d and calcium supplements for osteoporosis or vitamin b12 for pernicious anemia may be beneficial. -many health care professionals recom- mend a daily multivitamin-mineral supplement that provides 100 percent or less of the daily value for the listed nutrients.45 they reason that such a supplement is more likely to be beneficial than to cause harm. -people with small energy allowances would do well to become more active so they can afford to eat more food. -food is the best source of nutrients for everybody. -supplements are just that supplements to foods, not substitutes for them. -for any- one who is motivated to obtain the best possible health, it is never too late to learn to eat well, drink water, exercise regularly, and adopt other lifestyle habits such as quitting smoking and moderating alcohol use. -in summary the table below summarizes the nutrient concerns of aging. -although some nutrients need special attention in the diet, sup- plements are not routinely recommended. -the ever-growing number of older people creates an urgent need to learn more about how their nutrient requirements differ from those of others and how such knowledge can enhance their health. -nutrient effect of aging comments water energy fiber protein lack of thirst and decreased total body water make dehydra- tion likely. -mild dehydration is a common cause of confusion. -difficulty obtaining water or getting to the bathroom may compound the problem. -need decreases as muscle mass decreases (sarcopenia). -physical activity moderates the decline. -likelihood of constipation increases with low intakes and changes in the gi tract. -inadequate water intakes and lack of physical activity, along with some medications, compound the problem. -needs may stay the same or increase slightly. -vitamin b12 atrophic gastritis is common. -low-fat, high-fiber legumes and grains meet both protein and other nutrient needs. -deficiency causes neurological damage; supplements may be needed. -vitamin d increased likelihood of inadequate intake; skin synthesis declines. -daily sunlight exposure in moderation or supplements may be beneficial. -calcium intakes may be low; osteoporosis is common. -iron in women, status improves after menopause; deficiencies are linked to chronic blood losses and low stomach acid output. -stomach discomfort commonly limits milk intake; calcium substitutes or supplements may be needed. -adequate stomach acid is required for absorption; antacid or other medicine use may aggravate iron deficiency; vitamin c and meat increase absorption. -nutrition-related concerns of older adults nutrition may play a greater role than has been realized in preventing many changes once thought to be inevitable consequences of growing older. -the following discussions of vision, arthritis, and the aging brain show that nutrition may provide at least some protection against some of the conditions associated with aging. -vision one key aspect of healthy aging is maintaining good vision.46 age-related eye dis- eases that impair vision, such as cataract and macular degeneration, correlate with poor survival that cannot be explained by other risk factors.47 following a healthy diet as described by the dietary guidelines for americans is one way to protect against these age-related vision problems.48 cataracts cataracts are age-related thickenings in the lenses of the eyes that im- pair vision. -if not surgically removed, they ultimately lead to blindness. -cataracts cataracts (kat-ah-rakts): thickenings of the eye lenses that impair vision and can lead to blindness. -life cycle nutrition: adulthood and the later years 605 occur even in well-nourished individuals as a result of ultraviolet light exposure, ox- idative stress, injury, viral infections, toxic substances, and genetic disorders. -many cataracts, however, are vaguely called senile cataracts meaning caused by ag- ing. -in the united states, more than half of all adults 65 and older have a cataract. -oxidative stress appears to play a significant role in the development of cataracts, and the antioxidant nutrients may help minimize the damage. -studies have reported an inverse relationship between cataracts and dietary intakes of vi- tamin c, vitamin e, and carotenoids; taking supplements or eating fruits and veg- etables rich in these antioxidant nutrients seems to slow the progression or reduce the risk of developing cataracts.49 one other diet-related factor may play a role in the development of cataracts obesity.50 obesity appears to be associated with cataracts, but its role has not been identified. -risk factors that typically accompany overweight, such as inactivity, di- abetes, or hypertension, do not explain the association. -macular degeneration the leading cause of visual loss among older people is age-related macular degeneration, a deterioration of the macular region of the retina.51 as with cataracts, risk factors for age-related macular degeneration include oxidative stress from sunlight, and preventive factors may include supplements of antioxidant vitamins plus zinc and the carotenoids lutein and zeaxanthin.52 total dietary fat may also be a risk factor for macular degeneration, but the omega-3 fatty acids of fish may be protective. -arthritis more than 40 million people in the united states have some form of arthritis. -as the population ages, it is expected that the prevalence will increase to 60 million by 2020. osteoarthritis the most common type of arthritis that disables older people is os- teoarthritis, a painful deterioration of the cartilage in the joints. -during move- ment, the ends of bones are normally protected from wear by cartilage and by small sacs of fluid that act as a lubricant. -with age, the cartilage sometimes disintegrates, and the joints become malformed and painful to move. -one known connection between osteoarthritis and nutrition is overweight. -weight loss may relieve some of the pain for overweight persons with osteoarthri- tis, partly because the joints affected are often weight-bearing joints that are stressed and irritated by having to carry excess pounds. -interestingly, though, weight loss often relieves much of the pain of arthritis in the hands as well, even though they are not weight-bearing joints. -jogging and other weight-bearing exer- cises do not worsen arthritis. -in fact, both aerobic activity and strength training of- fer improvements in physical performance and pain relief, especially when accompanied by even modest weight loss.53 rheumatoid arthritis another type of arthritis known as rheumatoid arthri- tis has possible links to diet through the immune system.54 in rheumatoid arthritis, the immune system mistakenly attacks the bone coverings as if they were made of foreign tissue. -in some individuals, certain foods, notably vegetables and olive oil, may moderate the inflammatory response and provide some relief.55 the omega-3 fatty acids commonly found in fish oil reduce joint tenderness and improve mobility in some people with rheumatoid arthritis.56 the same diet recom- mended for heart health one low in saturated fat from meats and milk products and high in omega-3 fats from fish helps prevent or reduce the inflammation in the joints that makes arthritis so painful. -another possible link between nutrition and rheumatoid arthritis involves the oxidative damage to the membranes within joints that causes inflammation and swelling. -the antioxidant vitamins c and e and the carotenoids defend against ox- idation, and increased intakes of these nutrients may help prevent or relieve the pain of rheumatoid arthritis.57 risk factors for osteoarthritis: age smoking high bmi at age 40 lack of hormone therapy (in women) macular (mack-you-lar) degeneration: deterioration of the macular area of the eye that can lead to loss of central vision and eventual blindness. -the macula is a small, oval, yellowish region in the center of the retina that provides the sharp, straight-ahead vision so critical to reading and driving. -arthritis: inflammation of a joint, usually accompanied by pain, swelling, and structural changes. -osteoarthritis: a painful, degenerative disease of the joints that occurs when the cartilage in a joint deteriorates; joint structure is damaged, with loss of function; also called degenerative arthritis. -rheumatoid (roo-ma-toyd) arthritis: a disease of the immune system involving painful inflammation of the joints and related structures. -606 chapter 17 table 17-2 brain relationships summary of nutrient- brain function short-term memory performance in problem-solving tests mental health cognition vision neurotransmitter synthesis depends on an adequate intake of: vitamin b12, vitamin c, vitamin e riboflavin, folate, vitamin b12, vitamin c thiamin, niacin, zinc, folate folate, vitamin b6, vitamin b12, iron, vitamin e essential fatty acids, vitamin a tyrosine, tryptophan, choline gout (gowt): a common form of arthritis characterized by deposits of uric acid crystals in the joints. -purines: compounds of nitrogen-containing bases such as adenine, guanine, and caffeine. -purines that originate from the body are endogenous and those that derive from foods are exogenous. -neurons: nerve cells; the structural and functional units of the nervous system. -neurons initiate and conduct nerve impulse transmissions. -senile dementia: the loss of brain function beyond the normal loss of physical adeptness and memory that occurs with aging. -alzheimer s disease: a degenerative disease of the brain involving memory loss and major structural changes in neuron networks; also known as senile dementia of the alzheimer s type (sdat), primary degenerative dementia of senile onset, or chronic brain syndrome. -gout another form of arthritis, which most commonly affects men, is gout, a con- dition characterized by deposits of uric acid crystals in the joints. -uric acid derives from the breakdown of purines, primarily from those made by the body but also from those found in foods.58 foods such as meat and seafood that are rich in purines increase uric acid levels and the risk of gout, whereas milk products seem to lower uric acid levels and the risk of gout.59 treatment treatment for arthritis dietary or otherwise may help relieve dis- comfort and improve mobility, but it does not cure the condition. -traditional med- ical intervention for arthritis includes medication and surgery. -alternative therapies to treat arthritis abound, but none have proved safe and effective in scientific stud- ies. -popular supplements glucosamine, chondroitin, or a combination may re- lieve pain and improve mobility as well as over-the-counter pain relievers, but mixed reports from studies emphasize the need for additional research.60 drugs and supplements used to relieve arthritis can impose nutrition risks; many affect ap- petite and alter the body s use of nutrients, as highlight 17 explains. -the aging brain the brain, like all of the body s organs, responds to both genetic and environmental factors that can enhance or diminish its amazing capacities. -one of the challenges researchers face when studying the human brain is to distinguish among normal age-related physiological changes, changes caused by diseases, and changes that re- sult from cumulative, environmental factors such as diet. -the brain normally changes in some characteristic ways as it ages. -for one thing, its blood supply decreases. -for another, the number of neurons, the brain cells that specialize in transmitting information, diminishes as people age. -when the number of nerve cells in one part of the cerebral cortex diminishes, hearing and speech are affected. -losses of neurons in other parts of the cortex can impair mem- ory and cognitive function. -when the number of neurons in the hindbrain dimin- ishes, balance and posture are affected. -losses of neurons in other parts of the brain affect still other functions. -some of the cognitive loss and forgetfulness generally at- tributed to aging may be due in part to environmental, and therefore controllable, factors including nutrient deficiencies. -nutrient deficiencies and brain function nutrients influence the development and activities of the brain. -the ability of neurons to synthesize specific neurotransmit- ters depends in part on the availability of precursor nutrients that are obtained from the diet.61 the neurotransmitter serotonin, for example, derives from the amino acid tryptophan. -to function properly, the enzymes involved in neurotransmitter synthesis require vitamins and minerals. -thus nutrient deficiencies may contribute to the loss of memory and cognition that some older adults experience. -such losses may be prevent- able or at least diminished or delayed through diet and exercise.62 table 17-2 summa- rizes some of the better-known connections between brain function and nutrients. -in some instances, the degree of cognitive loss is extensive. -such senile demen- tia may be attributable to a specific disorder such as a brain tumor or alzheimer s disease. -table 17-3 lists common signs of dementia. -alzheimer s disease much attention has focused on the abnormal deterioration of the brain called alzheimer s disease, which affects 10 percent of u.s. adults by age 65 and 30 percent of those over 85. diagnosis of alzheimer s disease depends on its characteristic symptoms: the victim gradually loses memory and reasoning, the ability to communicate, physical capabilities, and eventually life itself.63 nerve cells in the brain die, and communication between the cells breaks down. -researchers are closing in on the exact cause of alzheimer s disease. -* clearly, ge- netic factors are involved.64 free radicals and oxidative stress also seem to be in- *a report on the genetic and other aspects of alzheimer s is available from alzheimer s disease educa- tion and referral center, p.o. -box 8250, silver springs, md 20907-8250. life cycle nutrition: adulthood and the later years 607 volved.65 nerve cells in the brains of people with alzheimer s disease show evidence of free-radical attack damage to dna, cell membranes, and proteins. -they also show evidence of the minerals that trigger free-radical attacks iron, copper, zinc, and aluminum. -some research suggests that the antioxidant nutrients can limit free-radical damage and delay or prevent alzheimer s disease.66 in alzheimer s disease, the brain develops senile plaques and neurofibril- lary tangles. -senile plaques are clumps of a protein fragment called beta- amyloid, whereas neurofibrillary tangles are snarls of the fibers that extend from the nerve cells. -both seem to occur in response to oxidative stress.67 researchers question whether these characteristics are the cause or the result of alzheimer s dis- ease.68 in fact, scientists are unsure whether these plaques and tangles are causing the damage, serving as markers, or even protecting by sequestering the proteins that begin the dementia process.69 late in the course of the disease there is a decline in the activity of the enzyme that assists in the production of the neurotransmitter acetylcholine from choline and acetyl coa. -acetylcholine is essential to memory, but supplements of choline (or of lecithin, which contains choline) have no effect on memory or on the pro- gression of the disease. -drugs that inhibit the breakdown of acetylcholine, on the other hand, have proved beneficial. -research suggests that cardiovascular disease risk factors such as high blood pressure, diabetes, and elevated levels of homocysteine may be related to the devel- opment of alzheimer s disease.70 diets designed to support a healthy heart, includ- ing omega-3 fatty acids and light-to-moderate alcohol intake, may benefit a healthy brain as well.71 treatment for alzheimer s disease involves providing care to clients and support to their families. -drugs are used to improve or at least to slow the loss of short-term memory and cognition, but they do not cure the disease. -other drugs may be used to control depression, anxiety, and behavior problems. -maintaining appropriate body weight may be the most important nutrition concern for the person with alzheimer s disease. -depression and forgetfulness can lead to changes in eating behaviors and poor food intake. -furthermore, changes in the body s weight-regulation system may contribute to weight loss. -perhaps the best that a caregiver can do nutritionally for a person with alzheimer s disease is to su- pervise food planning and mealtimes. -providing well-liked and well-balanced meals and snacks in a cheerful atmosphere encourages food consumption. -to min- imize confusion, offer a few ready-to-eat foods, in bite-size pieces, with seasonings and sauces. -to avoid mealtime disruptions, control distractions such as music, tel- evision, children, and the telephone. -in summary senile dementia and other losses of brain function afflict millions of older adults, and others face loss of vision due to cataracts or macular degeneration or cope with the pain of arthritis. -as the number of people over age 65 contin- ues to grow, the need for solutions to these problems becomes urgent. -some problems may be inevitable, but others are preventable and good nutrition may play a key role. -table 17-3 dementia common signs of agitated behavior becoming lost in familiar surroundings or circumstances confusion delusions loss of interest in daily activities loss of memory loss of problem-solving skills unclear thinking t i d e o t o h p / s i v a d h a r o b e d both foods and mental challenges nourish the brain. -food choices and eating habits of older adults older people are an incredibly diverse group, and for the most part, they are inde- pendent, socially sophisticated, mentally lucid, fully participating members of soci- ety who report themselves to be happy and healthy. -in fact, the quality of life senile plaques: clumps of the protein fragment beta-amyloid on the nerve cells, commonly found in the brains of people with alzheimer s dementia. -neurofibrillary tangles: snarls of the threadlike strands that extend from the nerve cells, commonly found in the brains of people with alzheimer s dementia. -608 chapter 17 among the elderly has improved, and their chronic disabilities have declined dra- matically in recent years.72 by practicing stress-management skills, maintaining physical fitness, participating in activities of interest, and cultivating spiritual health, as well as obtaining adequate nourishment, people can support a high qual- ity of life into old age (see table 17-4 for some strategies). -older people spend more money per person on foods to eat at home than other age groups and less money on foods away from home. -manufacturers would be wise to cater to the preferences of older adults by providing good-tasting, nutritious foods in easy-to-open, single-serving packages with labels that are easy to read. -such services enable older adults to maintain their independence and to feel a sense of control and involvement in their own lives. -another way older adults can take care of themselves is by remaining or becoming physically active. -as men- tioned earlier, physical activity helps preserve one s ability to perform daily tasks and so promotes independence. -familiarity, taste, and health beliefs are most influential on older people s food choices. -eating foods that are familiar, especially ethnic foods that recall family meals and pleasant times, can be comforting. -people 65 and over are less likely to diet to lose weight than younger people are, but they are more likely to diet in pur- suit of medical goals such as controlling blood glucose and cholesterol. -food assistance programs the nutrition screening initiative is part of a national effort to identify and treat nu- trition problems in older persons; it uses a screening checklist. -to determine the risk of malnutrition in older clients, health care professionals can keep in mind the char- acteristics and questions listed in table 17-5. an integral component of the older americans act (oaa) is the oaa nutrition program, formerly known as the elderly nutrition program. -its services are de- signed to improve older people s nutrition status and enable them to avoid medical problems, continue living in communities of their own choice, and stay out of in- stitutions. -its specific goals are to provide low-cost, nutritious meals; opportunities for social interaction; homemaker education and shopping assistance; counseling and referral to social services; and transportation. -the program s mission has al- ways been to provide more than a meal. -table 17-4 strategies for growing old healthfully choose nutrient-dense foods. -be alert to confusion as a disease symptom, and seek diagnosis. -be physically active. -walk, run, dance, swim, bike, or row for aerobic activity. -lift weights, do calisthenics, or pursue some other activity to tone, firm, and strengthen muscles. -practice balancing on one foot or doing simple move- ments with your eyes closed. -modify activities to suit changing abilities and tastes. -maintain appropriate body weight. -take medications as prescribed; see a physician before self-prescribing medicines or herbal remedies and a registered dietitian before self- prescribing supplements. -control depression through activities and friendships; seek professional help if necessary. -drink 6 to 8 glasses of water every day. -reduce stress (cultivate self-esteem, maintain a positive attitude, manage time wisely, know your limits, practice assertiveness, release tension, and take action). -for women, discuss with a physician the risks and benefits of estrogen replacement therapy. -for people who smoke, discuss with a physician strategies and programs to help you quit. -practice mental skills. -keep on solving math problems and crossword puzzles, playing cards or other games, reading, writing, imagining, and creating. -make financial plans early to ensure security. -accept change. -work at recovering from losses; make new friends. -cultivate spiritual health. -cherish personal values. -make life meaningful. -expect to enjoy sex, and learn new ways of enhancing it. -go outside for sunshine and fresh air as often as possible. -use alcohol only moderately, if at all; use drugs only as prescribed. -take care to prevent accidents. -expect good vision and hearing throughout life; obtain glasses and hearing aids if necessary. -take care of your teeth; obtain dentures if necessary. -be socially active play bridge, join an exercise or dance group, take a class, teach a class, eat with friends, volunteer time to help others. -stay interested in life pursue a hobby, spend time with grandchildren, take a trip, read, grow a garden, or go to the movies. -enjoy life. -table 17-5 risk factors for malnutrition in older adults life cycle nutrition: adulthood and the later years 609 disease eating poorly tooth loss or mouth pain economic hardship reduced social contact multiple medications involuntary weight loss or gain needs assistance elderly person these questions help determine the risk of malnutrition in older adults: do you have an illness or condition that changes the types or amounts of foods you eat? -do you eat fewer than two meals a day? -do you eat fruits, vegetables, and milk products daily? -is it difficult or painful to eat? -do you have enough money to buy the food you need? -do you eat alone most of the time? -t i d e o t o h p / g r e b n e e r g f f e j do you take three or more different prescribed or over-the- counter medications daily? -social interactions at a congregate meal site can be as nourishing as the foods served. -have you lost or gained 10 pounds or more in the last six months? -are you physically able to shop, cook, and feed yourself? -are you older than 80? -the oaa nutrition program provides for congregate meals at group settings such as community centers. -administrators try to select sites for congregate meals where as many eligible people as possible can participate. -volunteers may also de- liver meals to those who are homebound either permanently or temporarily; these home-delivered meals are known as meals on wheels. -although the home- delivery program ensures nutrition, its recipients miss out on the social benefits of the congregate meals. -therefore, every effort is made to persuade older people to come to the shared meals, if they can. -all persons aged 60 years and older and their spouses are eligible to receive meals from these programs, regardless of their in- come. -priority is given to those who are economically and socially needy. -an esti- mated 3 million of our nation s older adults benefit from these meals. -these programs provide at least one meal a day that meets a third of the rda for this age group, and they must operate five or more days a week. -many programs voluntarily offer additional services designed to appeal to older adults: provisions for special diets (to meet medical needs or religious preferences), food pantries, eth- nic meals, and delivery of meals to the homeless. -adding breakfast to the service in- creases energy and nutrient intakes, which helps to relieve hunger and depression.73 older adults can also take advantage of the senior farmers market nutrition program, which provides low-income older adults with coupons that can be ex- changed for fresh fruits, vegetables, and herbs at community-supported farmers markets and roadside stands. -this program increases fresh fruit and vegetable con- sumption, provides nutrition information, and even reaches the homebound eld- erly, a group of people who normally do not have access to farmers markets. -older adults can learn about the available programs in their communities by look- ing in the yellow pages of the telephone book under social services or senior citi- zens organizations. -* in addition, the local senior center and hospital can usually direct people to programs that provide nutrition and other health-related services. -meals for singles many older adults live alone, and singles of all ages face challenges in purchasing, storing, and preparing food. -large packages of meat and vegetables are often in- tended for families of four or more, and even a head of lettuce can spoil before one *to find a local provider, call eldercare locator at (800) 677-1116. congregate meals: nutrition programs that provide food for the elderly in conveniently located settings such as community centers. -meals on wheels: a nutrition program that delivers food for the elderly to their homes. -610 chapter 17 person can use it all. -many singles live in small dwellings and have little storage space for foods. -a limited income presents additional obstacles. -this section offers suggestions that can help to solve some of the problems singles face, beginning with a special note about the dangers of foodborne illness. -foodborne illness the risk of older adults getting a foodborne illness is greater than for other adults. -the consequences of an upset stomach, diarrhea, fever, vom- iting, abdominal cramps, and dehydration are oftentimes more severe, sometimes leading to paralysis, meningitis, or even death. -for these reasons, older adults need to carefully follow the food safety suggestions presented in chapter 19. dietary guidelines for americans 2005 older adults should not eat or drink unpasteurized milk, milk products, or juices; raw or undercooked eggs, meat, poultry, fish, or shellfish; or raw sprouts. -older adults should only eat certain deli meats and frankfurters that have been reheated to steaming hot. -spend wisely people who have the means to shop and cook for themselves can cut their food bills simply by being wise shoppers. -large supermarkets are usually less expensive than convenience stores. -a grocery list helps reduce impulse buying, and specials and coupons can save money when the items featured are those that the shopper needs and uses. -buying the right amount so as not to waste any food is a challenge for people eating alone. -they can buy fresh milk in the size best suited for personal needs. -pint-size and even cup-size boxes of milk are available and can be stored un- opened on a shelf for as long as three months without refrigeration. -many foods that offer a variety of nutrients for practically pennies have a long shelf life; staples such as rice, pastas, dry powdered milk, and dried legumes can be purchased in bulk and stored for months at room temperature. -other foods that are usually a good buy include whole pieces of cheese rather than sliced or shredded cheese, fresh produce in season, variety meats such as chicken livers, and cereals that require cooking instead of ready-to-serve cereals. -a person who has ample freezer space can buy large packages of meat, such as pork chops, ground beef, or chicken, when they are on sale. -then the meat can be immediately wrapped into individual servings for the freezer. -all the individual servings can be put in a bag marked appropriately with the contents and the date. -frozen vegetables are more economical in large bags than in small boxes. -after the amount needed is taken out, the bag can be closed tightly with a twist tie or rub- ber band. -if the package is returned quickly to the freezer each time, the vegetables will stay fresh for a long time. -finally, breads and cereals usually must be purchased in larger quantities. -again the amount needed for a few days can be taken out and the rest stored in the freezer. -grocers will break open a package of wrapped meat and rewrap the portion needed. -similarly, eggs can be purchased by the half-dozen. -eggs do keep for long periods, though, if stored properly in the refrigerator. -fresh fruits and vegetables can be purchased individually. -a person can buy fresh fruit at various stages of ripeness: a ripe one to eat right away, a semiripe one to eat soon after, and a green one to ripen on the windowsill. -if vegetables are pack- aged in large quantities, the grocer can break open the package so that a smaller amount can be purchased. -small cans of fruits and vegetables, even though they are more expensive per unit, are a reasonable alternative, considering that it is ex- pensive to buy a regular-size can and let the unused portion spoil. -be creative creative chefs think of various ways to use foods when only large amounts are available. -for example, a head of cauliflower can be divided into y r e g a m i k c o t s x e d n i / a k u d e n n o l i boxes of milk that can be stored at room temperature have been exposed to temper- atures above those of pasteurization just long enough to sterilize the milk a process called ultrahigh temperature (uht). -buy only what you will use. -life cycle nutrition: adulthood and the later years 611 thirds. -then one-third is cooked and eaten hot. -another third is put into a vinegar and oil marinade for use in a salad. -and the last third can be used in a casserole or stew. -a variety of vegetables and meats can be enjoyed stir-fried; inexpensive vegeta- bles such as cabbage, celery, and onion are delicious when crisp cooked in a little oil with herbs or lemon added. -interesting frozen vegetable mixtures are available in larger grocery stores. -cooked, leftover vegetables can be dropped in at the last minute. -a bonus of a stir-fried meal is that there is only one pan to wash. similarly, a microwave oven allows a chef to use fewer pots and pans. -meals and leftovers can also be frozen or refrigerated in microwavable containers to reheat as needed. -many frozen dinners offer nutritious options. -adding a fresh salad, a whole- wheat roll, and a glass of milk can make a nutritionally balanced meal. -also, single people shouldn t hesitate to invite someone to share meals with them whenever there is enough food. -it s likely that the person will return the invi- tation, and both parties will get to enjoy companionship and a meal prepared by others. -in summary older people can benefit from both the nutrients provided and the social inter- action available at congregate meals. -other government programs deliver meals to those who are homebound. -with creativity and careful shopping, those living alone can prepare nutritious, inexpensive meals. -physical activ- ity, mental challenges, stress management, and social activities can also help people grow old comfortably. -invite guests to share a meal. -e l i f r e t s a m nutrition portfolio www.thomsonedu.com/thomsonnow by eating a balanced diet, maintaining a healthy body weight, and engaging in a variety of physical, social, and mental activities, you can enjoy good health in later life. -visit older adults in your community and consider whether they have the finan- cial means, physical ability, and social support they need to eat adequately. -note whether they have experienced an unintentional loss of weight recently. -discuss how they occupy their time physically, socially, and mentally. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 17, then to nutrition on the net. -search for aging, arthritis, and alzheimer s on the u.s. government health information site: www.healthfinder.gov visit the national institute on aging: www.nia.nih.gov visit the american association of retired persons: www.aarp.org get nutrition tips for growing older in good health from the american dietetic association: www.eatright.org visit the national aging information center of the ad- learn more about cataracts and macular degeneration ministration on aging: www.aoa.gov visit the american geriatrics society: www.americangeriatrics.org from the national eye institute, the macular degeneration partnership, and the american society of cataract and refractive surgery: www.nei.nih.gov, www.macd.net, and www.ascrs.org 612 chapter 17 learn more about arthritis from the arthritis society, the arthritis foundation, and the national institute of arthri- tis and musculoskeletal and skin diseases: www.arthritis.ca, www.arthritis.org, and www.niams.nih.gov learn more about alzheimer s disease from the nia alzheimer s disease education and referral center and the study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. what roles does nutrition play in aging, and what roles can it play in retarding aging? -(pp. -595 597) 2. what are some of the physiological changes that occur in the body s systems with aging? -to what extent can aging be prevented? -(pp. -597 600) 3. why does the risk of dehydration increase as people age? -(p. 601) 4. why do energy needs usually decline with advancing age? -(p. 601) 5. which vitamins and minerals need special consideration for the elderly? -explain why. -identify some factors that complicate the task of setting nutrient standards for older adults. -(pp. -602 603) 6. discuss the relationships between nutrition and cataracts and between nutrition and arthritis. -(pp. -604 606) alzheimer s association: www.alzheimers.org and www.alz.org find out about federal government programs designed to help senior citizens maintain good health: www.seniors.gov 4. rats live longest when given diets that: a. eliminate all fat. -b. provide lots of protein. -c. allow them to eat freely. -d. restrict their energy intakes. -5. which characteristic is not commonly associated with atrophic gastritis? -a. inflamed stomach b. vitamin b12 toxicity c. bacterial overgrowth d. lack of intrinsic factor 6. on average, adult energy needs: a. decline 5 percent per year. -b. decline 5 percent per decade. -c. remain stable throughout life. -d. rise gradually throughout life. -7. which nutrients seem to protect against cataract development? -a. minerals b. lecithins c. antioxidants d. amino acids 7. what characteristics contribute to malnutrition in older 8. the best dietary advice for a person with osteoarthritis people? -(pp. -600 601, 607 609) might be to: these multiple choice questions will help you prepare for an exam. -answers can be found on p. 614. -1. life expectancy in the united states is about: a. avoid milk products. -b. take fish oil supplements. -c. take vitamin e supplements. -d. lose weight, if overweight. -a. -48 to 60 years. -b. -58 to 70 years. -c. 68 to 80 years. -d. 78 to 90 years. -2. the human life span is about: a. -85 years. -b. -100 years. -c. 115 years. -d. 130 years. -3. a 72-year-old person whose physical health is similar to that of people 10 years younger has a(n): a. chronological age of 62. b. physiological age of 72. c. physiological age of 62. d. absolute age of minus 10. -9. congregate meal programs are preferable to meals on wheels because they provide: a. nutritious meals. -b. referral services. -c. social interactions. -d. financial assistance. -10. the elderly nutrition program is available to: a. all people 65 years and older. -b. all people 60 years and older. -c. homebound people only, 60 years and older. -d. low-income people only, 60 years and older.. references 1. trends in aging united states and world- wide, morbidity and mortality weekly report 52 (2003): 101-106. -2. d. l. hoyert and coauthors, annual sum- mary of vital statistics: 2004, pediatrics 117 (2006): 168-183. -3. living well to 100: nutrition, genetics, inflammation, supplement to american journal of clinical nutrition 83 (2006): 401s-490s. -4. w. s. browner and coauthors, the genetics of human longevity, american journal of medi- cine 117 (2004): 851-860. -5. t. perls, genetic and environmental influ- ences on exceptional longevity and the age 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in aging men: the veterans affairs normative aging study, american journal of clinical nutrition 82 (2005): 627-635; p. quadri and coauthors, homocysteine, folate, and vitamin b-12 in mild cognitive impairment, alzheimer dis- ease, and vascular dementia, american journal of clinical nutrition 80 (2004): 114-122; s. seshadri and coauthors, plasma homocys- teine as a risk factor for dementia and alzheimer s disease, new england journal of medicine 346 (2002): 476-483. -71. r. uauy and a. d. dangour, nutrition in brain development and aging: role of essen- tial fatty acids, nutrition reviews 64 (2006): s24-s33; t. den heijer and coauthors, alcohol intake in relation to brain magnetic reso- nance imaging findings in older persons without dementia, american journal of clini- cal nutrition 80 (2004): 992-997; f. calon and coauthors, docosahexaenoic acid protects from dendritic pathology in an alzheimer s disease mouse model, neuron 43 (2004): 633-645. -72. v. a. freedman, l. g. martin, and r. f. schoeni, recent trends in disability and functioning among older adults in the united states: a systematic review, journal of the american medical association 288 (2002): 3137-3146. -73. e. a. gollub and d. o. weddle, improve- ments in nutritional intake and quality of life among frail homebound older adults receiv- ing home-delivered breakfast and lunch, journal of the american dietetic association 104 (2004): 1227-1235. -1. c 2. d 3. c 4. d 5. b 6. b 7. c 8. d 9. c 10. b highlight 17 nutrient-drug interactions people over the age of 65 take about one- third of all the over-the-counter and pre- scription drugs sold in the united states. -they receive an average of 13 prescriptions a year and may take as many as 6 drugs at a time. -they take a variety of non-vitamin- mineral supplements, such as glucosamine, as well.1 most often, they take these drugs and supplements for heart disease, but also to treat arthritis, res- piratory problems, and gastrointestinal disorders. -they often go to different doctors for each condition and receive different pre- scriptions from each. -to avoid harmful drug interactions, they need to inform all of their physicians and pharmacists of all the medicines being taken.2 these medicines enable people of all ages to enjoy better health, but they also bring side effects and risks. -this highlight focuses on some of the nutrition-related conse- quences of medical drugs, both prescription drugs and nonpre- scription (over-the-counter) drugs. -highlight 7 described the relationships between nutrition and the drug alcohol, and high- light 18 presents information on herbal supplements and other alternative therapies. -the actions of drugs most people think of drugs either as medicines that help them re- cover from illnesses or as illegal substances that lead to bodily harm and addiction. -actually, both uses of the term drug are cor- rect because any substance that modifies one or more of the body s functions is, technically, a drug. -even medical drugs have both desirable and undesirable consequences within the body. -consider aspirin. -one action of aspirin is to limit the produc- tion of certain prostaglandins. -some prostaglandins help to produce fevers, some sensitize pain receptors, some cause con- tractions of the uterus, some stimulate digestive tract motility, some control nerve impulses, some regulate blood pressure, some promote blood clotting, and some cause inflammation. -by interfering with prostaglandin actions, aspirin reduces fever and inflammation, relieves pain, and slows blood clotting, among other things. -a person cannot use aspirin to produce one of its effects with- out producing all of its other effects. -someone who is prone to strokes and heart attacks might take aspirin to prevent blood clot- ting, but it will also dull that person s sense of pain. -another per- son who takes aspirin only for pain will also experience slow blood clotting. -the anticlotting effect might be dangerous if it causes abnormal bleeding. -a single two-tablet dose of aspirin doubles the bleeding time of wounds, an effect that lasts from four to seven hours. -for this reason, physicians instruct clients to refrain from tak- ing aspirin before surgery. -i s b r o c / s d o o w d i v a d the interactions between drugs and nutrients hundreds of drugs and nutrients interact, and these interactions can lead to nutrient imbalances or interfere with drug effective- ness.3 adverse nutrient-drug interactions are most likely if drugs are taken over long periods, if several drugs are taken, or if nutri- tion status is poor or deteriorating. -understandably, then, elderly people with chronic diseases are most vulnerable. -nutrients and medications may interact in many ways: drugs can alter food intake and the absorption, metabo- lism, and excretion of nutrients. -foods and nutrients can alter the absorption, metabolism, and excretion of drugs. -the following paragraphs describe these interactions, and table h17-1 (p. 616) summarizes this information and provides specific examples. -altered food intake some medications can make eating difficult or unpleasant. -some induce nausea or vomiting, which diminishes the desire to eat. -some cause inflammation or lesions in the mouth, stomach, or in- testinal lining, resulting in pain or discomfort when food is eaten. -taste perceptions may change, leading to food aversions that may persist even after treatment has been discontinued. -all of these complications limit food intake and can lead to weight loss and malnutrition if not resolved. -some medications, such as megestrol acetate, stimulate food intake and encourage weight gain. -these medications may be prescribed in patients with debilitating diseases such as cancer or aids. -unintentional weight gain may result from the use of some antipsychotics, antidepressants, and corticosteroids (for example, prednisone). -people using these drugs do not feel satiated and sometimes gain 40 to 60 pounds in just a few months. -615 616 highlight 17 table h17-1 examples of nutrient-drug interactions drugs may alter food intake by: altering the appetite (amphetamines suppress appetite; corticosteroids increase appetite.) -interfering with taste or smell (amphetamines change taste perceptions.) -inducing nausea or vomiting (digitalis may do both.) -interfering with oral function (some antidepressants may cause dry mouth.) -causing sores or inflammation in the mouth (methotrexate may cause painful mouth ulcers.) -drugs may alter nutrient absorption by: changing the acidity of the digestive tract (antacids may interfere with iron and folate absorption.) -damaging mucosal cells (cancer chemotherapy may damage mucosal cells.) -binding to nutrients (bile acid binders bind to fat-soluble vitamins.) -foods and nutrients may alter drug absorption by: stimulating secretion of gastric acid (the antifungal agent ketoconazole is absorbed better with meals due to increased acid secretion.) -altering rate of gastric emptying (intestinal absorption of drugs may be delayed when they are taken with food.) -binding to drugs (calcium binds to tetracycline, reducing drug and calcium absorption.) -competing for absorption sites in the intestines (dietary amino acids interfere with levodopa absorption.) -drugs and nutrients may interact and alter metabolism by: acting as structural analogs (as do warfarin and vitamin k) using similar enzyme systems (phenobarbital induces liver enzymes that increase metabolism of folate, vitamin d, and vitamin k.) competing for transport on plasma proteins (fatty acids and drugs may compete for the same sites on the plasma protein albumin.) -increasing side effects of the drug (caffeine in beverages can increase adverse effects of stimulants.) -increasing drug action to excessive levels (grapefruit components may block metabolism of drugs and enhance drugs actions and side effects.) -drugs may alter nutrient excretion by: altering reabsorption in the kidneys (some diuretics increase the excretion of sodium and potassium.) -causing diarrhea or vomiting (diarrhea and vomiting may cause electrolyte losses.) -foods may alter medication excretion by: inducing activities of liver enzymes that metabolize drugs to allow their excretion (components of charcoal-broiled meats increase metabolism of warfarin, theophylline, and acetominophen.) -medications prescribed for obesity intentionally suppress the appetite and promote weight loss. -examples include sibutramine, amphetamines, and amphetamine-like compounds such as phen- termine. -when amphetamines are prescribed for other purposes, such as narcolepsy or attention-deficit/hyperactivity disorder, ap- petite suppression and weight loss may be unwanted side effects. -altered nutrient absorption nutrient malabsorption is most likely to occur with medications that damage the intestinal mucosa. -antineoplastic and antiretro- viral drugs are especially detrimental; nonsteroidal anti-inflamma- tory drugs (nsaids) and some antibiotics can have similar, though milder, effects. -some medications bind nutrients in the gi tract, preventing their absorption. -for example, bile acid binders, used to reduce cholesterol levels, also bind to the fat-soluble vitamins a, d, e, and k. some antibiotics, notably tetracycline and ciprofloxacin, bind to the calcium in foods and supplements, which reduces the absorption of both the drug and the calcium. -other minerals, such as iron, magnesium, and zinc, may also bind to antibiotics. -for this reason, pharmacists advise consumers to use dairy prod- ucts and all mineral supplements at least two hours apart from these medications. -medications, such as antacids, that reduce stomach acidity may interfere with the absorption of vitamin b12, folate, and iron. -other drugs impede absorption by interfering with the intestinal metabolism or transport of nutrients into mucosal cells. -for exam- ple, the antibiotics trimethoprim and pyrimethamine compete with folate for absorption into intestinal cells. -altered drug absorption most drugs are absorbed in the upper small intestine. -major influ- ences on drug absorption include the stomach emptying rate, level of acidity, and direct interactions with dietary components. -the drug s formulation also influences its absorption, and phar- macists often provide instructions advising whether food should be eaten or avoided when using a medication. -drugs reach the small intestine more quickly when the stom- ach is empty. -therefore, taking a medication with meals may de- lay its absorption, although the total amount absorbed may not be affected. -for example, aspirin works faster when taken on an empty stomach, but taking it with food is often encouraged to minimize stomach irritation. -both nutrients and nonnutrients may bind to drugs and inhibit their absorption. -for example, high-fiber diets may decrease the absorption of some tricyclic antidepressants. -phytates in foods can bind to digoxin, a drug prescribed for heart disease. -as men- tioned earlier, calcium and other minerals may bind to some an- tibiotics, reducing absorption of both the minerals and the drug. -altered metabolism drugs and nutrients interact metabolically because they use many of the same enzyme systems in the small intestine and the liver. -drugs may enhance or inhibit the activities of enzymes that are needed for nutrient metabolism, and conversely, dietary com- ponents may enhance or inhibit the activities of enzymes that break down drugs prior to excretion. -these alterations may affect the availability of nutrients, the actions of medications in the body, or various other physiological processes. -to appreciate how nutrient-drug interactions can affect me- tabolism, consider medicines that resemble vitamins in structure. -nutrient-drug interactions 617 the drug methotrexate, used to treat cancer and inflammatory conditions, resembles folate in structure (see figure h17-1) and competes with the enzyme that converts folate to its active form. -* the adverse effects of using methotrexate therefore include symptoms of folate deficiency. -these adverse effects can be re- duced by prescribing a pre-activated form of folate (called leucov- orin) along with methotrexate. -some foods affect the activities of enzymes that metabolize drugs or counteract the drugs effects in other ways. -for example, compounds in grapefruit juice interfere with enzymes that me- tabolize a number of drugs, resulting in increased blood concen- trations of the drugs, and consequently, stronger physiological effects.4 table h17-2 gives examples of drugs that interact with grapefruit juice, as well as some that are not affected. -figure h17-1 folate and methotrexate methotrexate (a drug used in the treatment of cancer and rheumatoid arthritis) is structurally similar to the b vitamin folate. -when this medication is used, it com- petes for the enzyme that normally activates folate, creating a secondary defi- ciency of folate. -notice the similarities in their chemical structures. -h2n h2n n n n oh n nh2 n n n n h ch2 n o cooh c nh ch ch2 ch2 cooh folate ch3 o cooh ch2 n c nh ch ch2 ch2 cooh methotrexate table h17-2 grapefruit juice drug interactions selected examples drugs affected by grapefruit juice drugs unaffected by grapefruit juice drug category cardiovascular drugs cholesterol-lowering drugs central nervous system drugs felodipine nicardipine nifedipine verapamil atorvastatin lovastatin simvastatin buspirone carbamazepine diazepam triazolam amlodipine diltiazem propafenone quinidine pravastatin clomipramine haloperidol clarithromycin itraconazole anti-infective drugs saquinavir estrogens anticoagulants immunosuppressants antiasthmatic drugs ethinylestradiol 17- -estradiol cyclosporine tacrolimus acenocoumarol warfarin prednisone theophylline source: d. g. bailey, m. o. arnold, and j. d. spence, inhibitors in the diet: grapefruit juice drug interactions, in r. h. levy and coeditors, metabolic drug interactions (philadelphia, pa.: lippincott williams & wilkins, 2000), pp. -661 669. a number of dietary factors affect the ac- tivity of the anticoagulant drug warfarin. -the most important interaction is with vita- min k, which is structurally similar to war- farin. -warfarin acts by blocking the enzyme that activates vitamin k, thereby preventing the synthesis of blood-clotting factors. -the amount of warfarin prescribed is depend- ent, in part, on how much vitamin k is in the diet. -if vitamin k consumption from foods or supplements were to increase dramatically, it could weaken the effect of the drug. -indi- viduals using warfarin are advised to con- sume similar amounts of vitamin k daily to keep warfarin activity stable. -the dietary sources highest in vitamin k are green leafy vegetables. -(mao) some combinations of foods and drugs can cause toxicity or exacerbate a drug s side effects. -the combination of tyramine, a compound in some foods, and monoamine oxidase inhibitors, medications that treat depression, can be fatal. -mao inhibitors block an enzyme that normally in- activates tyramine and the hormones epi- nephrine and norepinephrine. -when people who take mao inhibitors consume excessive tyramine, the tyramine causes a sudden re- lease of accumulated norepinephrine. -this surge in norepinephrine results in severe headaches, rapid heartbeat, and a dangerous increase in blood pressure. -for this reason, people taking mao inhibitors are advised to restrict their intakes of foods rich in tyramine (see table h17-3, p. 618). -altered nutrient excretion some medications may interfere with the reabsorption of minerals by the kidneys, in- creasing urinary losses. -for example, some diuretics accelerate the excretion of cal- cium, potassium, and magnesium. -others may cause mineral retention instead. -risk of mineral depletion is highest if multiple *other folate antagonists include aminopterin, sul- fasalazine, pyrimethamine, trimethoprim, triamterene, carbamazepine, phenytoin, phenobarbital, and primi- done. -618 highlight 17 table h17-3 tyramine-controlled diet foods restricted in a beverages: red wines including chianti, sherrya cheeses: meats: vegetables: other: aged cheeses, american, camembert, cheddar, gouda, gruy re, mozzarella, parmesan, provolone, romano, roquefort, stiltonb liver; dried, salted, smoked, or pickled fish; sausage, pepperoni; dried meats fava beans; italian broad beans; sauerkraut; fermented pickles and olives brewer s yeast;c all aged and fermented products; soy sauce in large amounts; cheese-filled breads, crackers, and desserts; salad dressings containing cheese note: the tyramine contents of foods vary from product to product depending on the methods used to prepare, process, and store the food. -in some cases, as little as 1 ounce of cheese can cause a severe hypertensive reaction in people taking monoamine oxidase (mao) inhibitors. -in general, the following foods contain small enough amounts of tyramine that they can be consumed in small quantities: ripe avocado, banana, yogurt, sour cream, acidophilus milk, buttermilk, raspberries, and peanuts. -amost wine and domestic beer can be consumed in small quantities. -bunfermented cheeses, such as ricotta, cottage cheese, and cream cheese, are allowed. -cproducts made with baker s yeast are allowed. -drugs with the same effect are used, if kidney function is impaired, or if medications are used for a long time. -a number of drugs can increase excretion of vitamin b6. -an ex- ample is isoniazid (inh), an antituberculosis drug that is similar in structure to vitamin b6. -this drug induces excretion of vitamin b6 and therefore has the potential to create a vitamin b6 deficiency. -because the drug must be taken for at least six months to treat in- fection, vitamin b6 supplements are routinely given to prevent deficiency. -altered drug excretion nutrients may influence the reabsorption of drugs by the kidneys. -for example, the amount of the medication lithium that is reab- sorbed by the kidneys correlates with the amount of sodium reab- sorbed. -consequently, dehydration or sodium depletion, which increase sodium reabsorption, may result in lithium retention. -similarly, a person with a high sodium intake will excrete more sodium in the urine and therefore more lithium. -individuals using lithium are advised to maintain a consistent sodium intake from day to day in order to maintain a stable blood level of lithium. -references urine acidity can also affect medication excretion. -the medica- tion quinidine, used to treat arrhythmias, is excreted more readily in acidic urine. -foods or drugs that cause urine to become more alkaline (for example, sodium bicarbonate) may reduce quinidine excretion and raise blood levels. -the inactive ingredients in drugs besides the active ingredients, medicines may contain other sub- stances such as sugar, sorbitol, lactose, and sodium. -for most people who use medicines on occasion and in small amounts, such ingredients pose no problem. -when medicines are taken regularly or in large doses, however, people on special diets may need to be aware of these additional ingredients and their effects. -sugar, sorbitol, and lactose many liquid preparations contain sugar or sorbitol to make them taste better. -for people who must regulate their intakes of carbo- hydrates, such as people with diabetes, the amount of sugar in these medicines may need to be considered. -large doses of liq- uids containing sorbitol may cause diarrhea. -the lactose added as filler to some medications may cause problems for people who are lactose intolerant. -sodium antibiotics and antacids often contain sodium. -people who take alka seltzer, for example, may not realize that a single two-tablet dose may exceed their recommended sodium intake for a whole day. -in addition, antacids neutralize stomach acid, and many nu- trients depend on acid for their digestion. -taking any antacid reg- ularly will reduce the absorption of many nutrients. -nutrient interactions and risks are not unique to prescription drugs. -people who buy over-the-counter drugs also need to pro- tect themselves. -the increasing availability of over-the-counter drugs allows people to treat themselves for many ailments from arthritis to yeast infections. -consumers need to ask their physi- cians about potential interactions and check with their pharma- cists for instructions on taking drugs with foods. -if problems arise, they should seek professional care without delay. -1. r. s. wold and coauthors, increasing trends 3. l. e. schmidt and k. dalhoff, food-drug 4. m. f. paine and coauthors, a in elderly persons use of nonvitamin, nonmineral dietary supplements and con- current use of medications, journal of the american dietetic association 105 (2005): 54-63. -2. k. e. anderson and d. j. greenblatt, assess- ing and managing drug-nutrient interac- tions, journal of the american pharmaceutical association 42 (2002): s28-s29. -interactions, drugs 62 (2002): 1481-1502; l. chan, drug-nutrient interaction in clinical nutrition, current opinion in clinical nutri- tion and metabolic care 5 (2002): 327-332; j. m. sorensen, herb-drug, food-drug, nutri- ent-drug, and drug-drug interactions: mech- anisms involved and their medical implications, journal of alternative and complementary medicine 8 (2002): 293-308. furanocoumarin-free grapefruit juice estab- lishes furanocoumarins as the mediators of the grapefruit juice-felodipine interaction, american journal of clinical nutrition 83 (2006): 1097-1105. this page intentionally left blank frank rothe/getty images throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow how to: practice problems nutrition portfolio journal nutrition in your life no doubt, you re familiar with the recommendations. -eat more veggies. -eat more fiber. -eat more fish. -put down the saltshaker. -limit the fat. -be active. -don t smoke. -and don t drink too much alcohol. -what s the deal? -if you follow this advice, will it really make a difference in how well or how long you live? -in a word, yes. -you can bet your life on it. -if you could grow old in good health without having a heart attack or stroke, or getting diabetes, hypertension, or cancer, wouldn t you be willing to do just about anything including improving your diet and activity habits? -of course, you would. -and you can start today. -diet and health infectious diseases such as smallpox once claimed the lives of many children and limited the average life expectancy of adults. -thanks to medical science s ability to identify disease-causing microorganisms and develop preventive strategies, most people now live well into their later years, and the average life expectancy far exceeds that of our ancestors. -in developed nations, purification of water and safe handling of foods help prevent the spread of infection. -antibi- otics and immunizations provide additional protection for individuals. -despite these advances, some infectious diseases still endanger many lives today. -growing threats around the globe include bioterrorism, the emer- gence of new diseases such as sars (sudden acute respiratory syndrome), west nile virus infections, and disease strains such as tuberculosis and some food- borne infections that have become resistant to antibiotics.1 although govern- ment security and public health measures such as emergency preparedness, safe food and water supplies, and medical care do much to contain infectious diseases, people are exposed to millions of microbes each day. -nutrition can- not directly prevent or cure infectious diseases, but good nutrition can strengthen, and malnutrition can weaken, the body s defenses against them. -this chapter begins with a description of the immune system and the re- lationships between nutrition and infectious diseases, but the bulk of the chapter focuses on the chronic diseases that pose the greatest threat to the lives of most people in developed countries. -these chronic diseases develop over a lifetime as a result of metabolic abnormalities induced by such factors as genetics, age, gender, and lifestyle. -as you have learned, diet is among the many lifestyle factors that influence the development of chronic diseases.2 nutrition and infectious diseases it is difficult to know exactly where infectious diseases fall among the leading causes of death. -compared with chronic diseases, infectious diseases pose a much greater challenge for public health officials who track disease prevalence. -one physician might classify an ear infection as an infectious disease, whereas another calls it a c h a p t e r 18 chapter outline nutrition and infectious diseases the immune system nutrition and immunity hiv and aids nutrition and chronic diseases cardiovascular disease how atherosclerosis develops risk factors for coronary heart disease recommen- dations for reducing coronary heart disease risk hypertension how hypertension develops risk factors for hypertension treatment of hypertension diabetes mellitus how diabetes develops complications of diabetes recommendations for diabetes cancer how cancer develops recommendations for reducing cancer risk recommendations for chronic diseases highlight 18 complementary and alternative medicine other lifestyle factors that contribute to the development of chronic diseases: physical inactivity overweight tobacco use alcohol and drug abuse infectious diseases: diseases caused by bacteria, viruses, parasites, or other microorganisms that can be transmitted from one person to another through air, water, or food; by contact; or through vector organisms such as mosquitoes. -bioterrorism: the intentional spreading of disease-causing microorganisms or toxins. -621 622 chapter 18 organs of the immune system: spleen lymph nodes thymus cells of the immune system: phagocytes: neutrophils macrophages lymphocytes: b-cells t-cells two types of immune system cells ingest and destroy foreign antigens by phagocyto- sis: neutrophils and macrophages. -disease of the ear. -trends change quickly as well. -a disease, such as aids, that did not even exist until the early 1980s may suddenly appear and become one of the leading causes of death. -a preventive strategy, such as food irradiation, may just as quickly eliminate hundreds of thousands of cases of foodborne infections each year. -public health strategies help the entire country defend against the spread of infec- tion, and each individual s immune system provides a personal line of defense. -a strong immune system depends on adequate nutrition. -poor nutrition weakens the immune system, which increases susceptibility to infections. -the immune system the immune system defends the body so diligently and silently that people do not even notice the thousands of enemy attacks mounted against them every day (the accompanying glossary defines immune system terms). -if the immune system fails, though, the body suddenly becomes vulnerable to every wayward disease-causing agent that comes its way. -infectious disease invariably follows. -the body s first lines of defense against foreign substances the skin, mucous mem- branes, and gi tract normally deter invaders. -if an invader penetrates these barriers and gains entry into the body, then the organs and cells of the immune system race into action. -foreign substances that elicit such a response are called antigens. -exam- ples include bacteria, viruses, toxins, and food proteins that cause allergies. -of the 100 trillion cells that make up the human body, one in every hundred is a white blood cell. -two types of white blood cells, the phagocytes and lympho- cytes, defend the body against infectious diseases. -phagocytes phagocytes, the scavengers of the immune system, are the first to arrive at the scene if an invader, such as a microorganism, gains entry. -upon recog- nizing the foreign invader, the phagocyte engulfs and digests it, if possible, in a process called phagocytosis. -phagocytes also secrete special proteins called cy- tokines that activate the metabolic and immune responses to infection. -lymphocytes: b-cells there are two distinct types of lymphocytes: b-cells and t- cells. -b-cells respond to infection by rapidly dividing and producing large proteins known as antibodies. -antibodies travel in the bloodstream to the site of the infec- tion. -there they stick to the surfaces of the foreign particles and kill or otherwise in- activate them, making the foreign particles easy for the phagocytes to ingest. -the antibodies are members of a class of proteins known as immunoglobu- lins literally, large globular proteins that produce immunity. -antibodies react se- lectively to a specific foreign organism, and the b-cells retain a memory of how to make them. -consequently, the immune system can respond with greater speed the next time it encounters the same foreign organism. -b-cells play a major role in re- sistance to infection. -lymphocytes: t-cells the t-cells travel directly to the invasion site to battle the invaders. -t-cells recognize the antigens displayed on the surfaces of phagocyte cells and multiply in response. -then they release powerful chemicals to destroy all the g lossary of immune system terms b-cells: lymphocytes that produce antibodies. -b stands for bone marrow where the b-cells develop and mature. -cytokines (sigh-toe-kines): special proteins that direct immune and inflammatory responses. -immunoglobulins (im-you-noh- glob-you-linz): proteins capable of acting as antibodies. -lymphocytes (lim-foh-sites): white blood cells that participate in acquired immunity; b-cells and t-cells. -immune system: the body s phagocytes (fag-oh-sites): white natural defense against foreign materials that have penetrated the skin or mucous membranes. -blood cells (neutrophils and macrophages) that have the ability to ingest and destroy foreign substances. -phagein (cid:2) to eat phagocytosis (fag-oh-sigh-toh- sis): the process by which phagocytes engulf and destroy foreign materials. -t-cells: lymphocytes that attack antigens. -t stands for the thymus gland, where the t-cells mature. -reminders: antibodies are large proteins of the blood and body fluids, produced by the immune system in response to the invasion of the body by foreign molecules (usually proteins called antigens). -antibodies combine with and inactivate the foreign invaders, thus protecting the body. -antigens are substances that elicit the formation of antibodies or an inflammation reaction from the immune system. -foreign particles that have this antigen on their surfaces. -as the t-cells begin to win the battle against infection, they release signals to slow down the immune response. -unlike the phagocytes, which are capable of inactivating many different types of invaders, t-cells are highly specific. -each t-cell can attack only one type of anti- gen. this specificity is remarkable, for nature creates millions of antigens. -after de- stroying a particular antigen, some t-cells retain the necessary information to serve as memory cells so that the immune system can rapidly produce the same type of t-cells again if the identical infection recurs. -t-cells actively defend the body against fungi, viruses, parasites, and a few types of bacteria; they can also destroy cancer cells. -in organ transplant patients, t-cells participate in the rejection of newly transplanted tissues, which is why physicians prescribe immunosuppressive drugs following such surgery. -nutrition and immunity of all the body s systems, the immune system responds most sensitively to subtle changes in nutrition status. -malnutrition compromises immunity.3 impaired im- munity opens the way for infectious diseases, which typically raise nutrient needs and lower food intake. -consequently, nutrition status suffers further.4 thus disease and malnutrition create a synergistic downward spiral that must be broken for recovery to occur (see figure 18-1). -impaired immunity is a hallmark of protein-energy malnutrition (pem). -table 18-1 presents the effects of pem on the body s defenses. -as chapter 6 explained, without sufficient protein to make antibodies, the immune system loses its ability to fight infections. -deficiencies of vitamins and minerals also diminish the im- mune response, as may excesses.5 likewise, interactions between nutrients may en- hance or impair immunity. -quite simply, optimal immunity depends on optimal nutrition enough, but not too much, of each of the nutrients. -people with weak- ened immune systems, such as the elderly, may benefit from a nutritious diet and supplements of selected nutrients. -hiv and aids perhaps the most infamous infectious disease today is aids (acquired immune deficiency syndrome). -aids develops from infection by hiv (human immun- odeficiency virus), which is transmitted by direct contact with contaminated body fluids, including semen, vaginal secretions, and blood (but not saliva), or by passage of the infection from a mother to her infant during pregnancy, birth, or breastfeeding. -hiv attacks the immune system and disables the body s defenses against other diseases. -then these diseases, which would produce only mild, if any, illness in people with healthy immune systems, destroy health and life. -table 18-2 (p. 624) shows the impact of aids worldwide and in the united states. -for many years, the devastating effects of hiv infection seemed unstoppable. -how- ever, in the mid-to-late 1990s, the death rate in the united states from aids began table 18-1 on the body s defense systems effects of protein-energy malnutrition (pem) body s defense system effects of pem skin thinned, with less connective tissue to serve as a barrier to protect underlying tissues; delayed skin sensitivity reaction to antigens digestive tract and other body linings antibody secretions and immune cell number reduced lymph tissuesa general response immune system organs reduced in size; cells of immune defense depleted invader kill time prolonged; circulating immune cells reduced; antibody response impaired alymph tissues include the thymus gland, lymph nodes, and spleen. -diet and health 623 figure 18-1 nutrition and immunity regardless of where a person enters the spiral, malnutrition, illness, and weak- ened immunity interact to compromise recovery and worsen malnutrition. -d illn e s s m a n d o li s e tit e p n n a r iti o m a l n u t t e r e d m e t a s o f l o s a a l b p n status nity u m u triti o n i m p a i r e d d i m e n w e a k e e d illn e ss e te rioration n statu s n e s w o r e r d of n u tritio furt h nutrients known to affect immunity: protein fatty acids vitamin a vitamin e vitamin b6 folate vitamin c iron zinc selenium synergistic (sin-er-jis-tick): multiple factors operating together in such a way that their combined effects are greater than the sum of their individual effects. -aids (acquired immune deficiency syndrome): the late stage of hiv infection, in which severe complications develop. -hiv (human immunodeficiency virus): the virus that causes aids. -the infection progresses to become an immune system disorder that leaves its victims defenseless against numerous infections. -624 chapter 18 table 18-2 at a glance, 2005 hiv and aids epidemic world united states 40,300,000 1,100,000 4,900,000 3,100,000 43,000 18,000 living with hiv or aids newly infected with hiv aids deaths to decline, and the progression from hiv to aids slowed dramatically.6 even though remarkable progress has been made in understanding and treating hiv infection, the disease still has no cure. -without a cure, the best course is prevention. -unlike the chronic diseases featured in the remainder of this chapter, aids prevention does not in any way depend on good nutrition. -although good nutrition cannot prevent or cure aids, an adequate diet may improve responses to drugs, shorten hospital stays, promote independence, and improve the quality of life. -in addition, because common food bacteria can easily overwhelm a compromised immune sys- tem, attention to food safety is critical. -(chapter 19 provides food safety strategies.) -in summary public health measures such as purification of water and safe handling of food help prevent the spread of infection in developed nations, and immu- nizations and antibiotics protect individuals. -nevertheless, some infectious diseases still endanger people today. -nutrition cannot prevent or cure infec- tious diseases, but adequate intakes of all the nutrients can help support the immune system as the body defends against disease-causing agents. -if the im- mune system is impaired because of malnutrition or diseases such as aids, a person becomes vulnerable to infectious disease. -nutrition and chronic diseases figure 18-2 shows the ten leading causes of death in the united states.7 four of these causes, including the top three, have some relationship with diet. -taken together, these four conditions account for 60 percent of the nation s more than 2 million deaths each year. -worldwide, statistics are similar, with developing nations sharing many of the same chronic diseases as developed nations.8 this chapter explains how the major chronic diseases develop and summarizes their major links with nutrition. -earlier chapters that described the connections be- tween individual nutrients and diseases may have left the mistaken impression of one disease one nutrient relationships. -indeed, valid links do exist between satu- rated fat and heart disease, calcium and osteoporosis, and antioxidant nutrients and cancer, but focusing only on these links oversimplifies the story. -in reality, each figure 18-2 the ten leading causes of death in the united statesa many deaths have multiple causes, but diet influences the development of several chronic diseases notably, heart disease, some types of cancer, stroke, and diabetes. -heart disease cancers strokes chronic lung diseases accidentsb diabetes mellitus alzheimer s disease pneumonia and influenza kidney diseases blood infections key: diet related alcohol related other causes 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 deaths per 100,000 population a b rates are age adjusted to allow relative comparisons of mortality among groups and over time. -motor vehicle and other accidents are the leading cause of death among people aged 15 24, followed by homicide, suicide, cancer, and heart disease. -alcohol contributes to about half of all accident fatalities. -source: data from national center for health statistics, 2006. diet and health 625 s e g a m i y t t e g / c s i d o t o h p vegetables rich in fiber, phytochemicals, and the antioxidant nutrients (beta-carotene, vita- min c, and vitamin e) help to protect against chronic diseases. -nutrient may have connections with several diseases because its role in the body is not specific to a disease, but to a body function. -furthermore, each of the chronic diseases develops in response to multiple risk factors, including many nondietary factors such as genetics, physical inactivity, and smoking. -this chapter presents an integrated and balanced approach to disease prevention, paying careful attention to all of the factors involved. -figure 18-3 illustrates some of the relationships be- tween risk factors and chronic diseases. -notice how many of the diseases listed in figure 18-3 have a genetic component. -a family history of a certain disease is a powerful indicator of a person s tendency to contract that disease. -still, lifestyle factors are often pivotal in determining whether that tendency will be expressed. -genetics and lifestyle often work synergistically; for instance, cigarette smoking is especially likely to bring on heart disease in people who are genetically predisposed to develop it. -not smoking would benefit everyone s health, of course, regardless of genetic predisposition, but some recommendations to prevent chronic diseases best meet an individual s needs when family history is con- sidered. -for example, women with a family history of breast cancer might reduce their risks if they abstain from alcohol, whereas those with a family history of heart disease might benefit from one or two glasses of wine a week. -in summary heart disease, cancers, and strokes are the three leading causes of death in the united states, and diabetes also ranks among the top ten. -all four of these chronic diseases have significant links with nutrition, although other lifestyle risk factors and genetics are also important. -figure 18-3 risk factors and chronic diseases diet risk factors other risk factors s d o d fo kle n e k e k d/or trans fat er inta eral inta d fat, a drate/fib alty or pic d/or min aturate ol inta y h o arb h h in fat, s ar inta e of s o x c min a e alc ple g siv h inta m w vita u diet hig o h s s w c e c hig hig x o e l n e g o l e k e k n k e s o u c c a b nts a min nta o ntal c style d to ntary life n g a kin o stre m s s s e m n viro n e s etic e g a e d e s i s e s a e s d c n o r h c i cancers hypertension diabetes (type 2) osteoporosis atherosclerosis obesity stroke diverticulosis dental and oral disease some cancers atherosclerosis stroke and heart attack obesity hypertension gallbladder disease diabetes this chart shows that the same risk factor can affect many chronic diseases. -notice, for example, how many diseases have been linked to a sedentary lifestyle. -the chart also shows that a particular disease, such as atherosclerosis, may have several risk factors. -this flow chart shows that many of these conditions are themselves risk factors for other chronic diseases. -for example, a person with diabetes is likely to develop atherosclerosis and hypertension. -these two conditions, in turn, worsen each other and may cause a stroke or heart attack. -notice how all of these chronic diseases are linked to obesity. -626 chapter 18 plaque associated with atherosclerosis is known as atheromatous (ath-er-oh- ma-tus) plaque. -reminder: inflammation is an immunologi- cal response to cellular injury characterized by an increase in white blood cells, red- ness, heat, pain, swelling, and often loss of function of the affected body part. -cardiovascular disease the major causes of death around the world today are diseases of the heart and blood vessels, collectively known as cardiovascular disease (cvd). -(the accom- panying glossary defines this and other heart disease terms.) -in the united states, cardiovascular disease claims the lives of nearly 1 million people each year.9 coronary heart disease (chd) is the most common form of cardiovascular disease and is usually caused by atherosclerosis in the coronary arteries that supply blood to the heart muscle. -atherosclerosis is the accumulation of lipids and other materials in the arteries. -how atherosclerosis develops as highlight 16 pointed out, no one is free of the fatty streaks that may one day be- come the plaques of atherosclerosis. -for most adults, the question is not whether you have plaques, but how advanced they are and what you can do to slow or re- verse their progression. -atherosclerosis or hardening of the arteries usually begins with the accumula- tion of soft fatty streaks along the inner arterial walls, especially at branch points (see figure h16-1 on p. 587). -these fatty streaks gradually enlarge and harden as they fill with cholesterol, other lipids, and calcium, and they become encased in fi- brous connective tissue, forming plaques. -plaques stiffen the arteries and narrow the passages through them. -most people have well-developed plaques by the age of 30. as chapter 5 pointed out, a diet high in saturated fat is a major contributor to the development of plaques and the progression of atherosclerosis.10 but athero- sclerosis is much more than the simple accumulation of lipids within the artery wall it is a complex inflammatory response to tissue damage. -indeed, extensive evidence confirms that inflammation is centrally involved in all stages of ather- osclerosis.11 inflammation the cells lining the blood vessels may incur damage from high ldl cholesterol, hypertension, toxins from cigarette smoking, elevated homocys- g lossary of heart disease terms aneurysm (an-you-rizm): an coronary heart disease (chd): abnormal enlargement or bulging of a blood vessel (usually an artery) caused by damage to or weakness in the blood vessel wall. -the damage that occurs when the blood vessels carrying blood to the heart (the coronary arteries) become narrow and occluded. -primary hypertension; hypertension that is caused by a specific disorder such as kidney disease is known as secondary hypertension. -angina (an-jye-nah or an-ji-nah): a embolism (em-boh-lizm): the painful feeling of tightness or pressure in and around the heart, often radiating to the back, neck, and arms; caused by a lack of oxygen to an area of heart muscle. -chd risk equivalents: disorders that raise the risk of heart attacks, strokes, and other complications associated with cardiovascular disease to the same degree as existing chd. -these disorders include symptomatic carotid artery disease, peripheral arterial disease, abdominal aortic aneurysm, and diabetes mellitus. -coronary arteries: blood vessels that supply blood to the heart. -obstruction of a blood vessel by an embolus (em-boh-luss), or traveling clot, causing sudden tissue death. -embol (cid:2) to insert, plug heart attack: sudden tissue death caused by blockages of vessels that feed the heart muscle; also called myocardial (my-oh-kar- dee-al) infarction (in-fark-shun) or cardiac arrest. -myo (cid:2) muscle cardial (cid:2) heart infarct (cid:2) tissue death hypertension: higher-than-normal blood pressure. -hypertension that develops without an identifiable cause is known as essential or prehypertension: slightly higher- than-normal blood pressure, but not as high as hypertension (see table 18-4). -stroke: an event in which the blood flow to a part of the brain is cut off; also called cerebrovascular accident (cva). -cerebro (cid:2) brain vascular (cid:2) blood vessels thrombosis (throm-boh-sis): the formation of a thrombus (throm-bus), or a blood clot, that may obstruct a blood vessel, causing gradual tissue death. -thrombo (cid:2) clot transient ischemic (is-key-mik) attack (tia): a temporary reduction in blood flow to the brain, which causes temporary symptoms that vary depending on the part of the brain affected. -common symptoms include light-headedness, visual disturbances, paralysis, staggering, numbness, and inability to swallow. -reminders: atherosclerosis is a type of artery disease characterized by plaques along the inner walls of the arteries. -cardiovascular disease (cvd) is a general term for all diseases of the heart and blood vessels. -plaques are mounds of lipid material, mixed with smooth muscle cells and calcium, that develop in the artery walls in atherosclerosis. -teine, or some viral and bacterial infections.12 such damage increases the perme- ability of the blood vessel walls and elicits an inflammatory response. -the immune system sends in macrophages, and the smooth muscle cells of the artery wall try to repair the damage. -particles of ldl cholesterol become trapped in the blood ves- sel walls. -free radicals produced during inflammatory responses oxidize the ldl cholesterol, and the macrophages engulf it. -the macrophages swell with large quantities of oxidized ldl cholesterol and eventually become the cells of plaque. -ar- terial damage and the inflammatory response also favor the formation of blood clots and allow minerals to harden plaque and form the fibrous connective tissue that encapsulates it. -the inflammatory response of atherosclerosis weakens the walls of the arteries and may cause an aneurysm the abnormal bulging of a blood vessel wall. -aneurysms can rupture and lead to massive bleeding and death, particularly when a large blood vessel such as the aorta is affected. -the central role of the inflamma- tory response in atherosclerosis has led researchers to look for signs or markers of in- flammation in the blood vessel walls. -one of the most promising of these markers is a protein known as c-reactive protein (crp). -high levels of crp have proved to more accurately predict future heart attack than high ldl cholesterol, which has a strong relationship with atherosclerosis, as a later section explains.13 plaques once plaques have formed, a sudden spasm or surge in blood pressure in an artery can tear away part of the fibrous coat covering a plaque, causing it to rup- ture. -some types of plaque are more unstable than others and are therefore more vulnerable to rupture.14 such plaques have a thin fibrous cap, a large lipid core, and an abundance of macrophages characteristics that undermine plaque stability.15 researchers now know that the composition of a plaque rather than the size of a plaque (and how much arterial blockage it causes) is a key predictor of plaque rup- ture and subsequent clot formation.16 when plaque ruptures, the body responds to the damage as it would to other tissue injuries. -blood clots platelets are tiny disc-shaped bodies that cover an injured or dam- aged area, and along with other factors, they form a clot. -abnormal blood clotting can trigger life-threatening events. -for example, a blood clot may gradually grow large enough to restrict or close off a blood vessel (thrombosis). -a clot may also break free from an artery wall and travel through the circulatory system until it lodges in a small artery and suddenly shuts off flow to the tissues (embolism). -the action of platelets is under the control of certain eicosanoids, known as prostaglandins and thromboxanes, which are made from the 20-carbon omega-6 and omega-3 fatty acids (introduced in chapter 5). -each eicosanoid plays a specific role in helping to regulate many of the body s activities. -sometimes their actions oppose each other.17 for example, one eicosanoid prevents clot formation, and an- other promotes it. -similarly, one dilates the blood vessels, and another constricts them. -when omega-3 fatty acids are abundant in the diet, they make more of the kinds of eicosanoids that favor heart health.18 blood pressure and atherosclerosis the heart must create enough pressure to push blood through the circulatory system. -when arteries are narrowed by plaques, clots, or both, blood flow is restricted, and the heart must then generate more pres- sure to deliver blood to the tissues. -this higher blood pressure further damages the artery walls, and plaques and clots are especially likely to form at damage points. -thus the development of atherosclerosis is a self-accelerating process. -(a later sec- tion describes additional consequences of high blood pressure.) -the result: heart attacks and strokes when atherosclerosis in the coronary arteries becomes severe enough to restrict blood flow and deprive the heart muscle of oxygen, chd develops. -the person with chd often experiences pain and pressure in the area around the heart (angina). -if blood flow to the heart is cut off and that area of the heart muscle dies, a heart attack results. -restricted blood flow to the brain causes a transient ischemic attack (tia) or stroke. -coronary heart diet and health 627 macrophages are large, phagocytic cells of the immune system. -macro = large phagein = to eat a coronary thrombosis blocks blood flow through an artery that feeds the heart muscle. -a cerebral thrombosis blocks blood flow through an artery that feeds the brain. -eicosanoids help to regulate: blood pressure blood clot formation blood vessel contractions immune response nerve impulse transmissions major sources of omega-3 fatty acids: vegetable oils (canola, soybean, flaxseed) walnuts, flaxseeds fatty fish (mackerel, salmon, sardines) c-reactive protein (crp): a protein released during the acute phase of infection or inflammation that enhances immunity by promoting phagocytosis and activating platelets. -its presence may be used to assess a person s risk of an impending heart attack or stroke. -platelets: tiny, disc-shaped bodies in the blood, important in blood clot formation. -628 chapter 18 some risk factors, such as diet and physical activity, are modifiable, meaning that they can be changed; others, such as genetics, age, and gender, cannot be changed. -table 18-3 risk factors for chd major risk factors for chd (not modifiable) increasing age male gender family history of premature heart disease major risk factors for chd (modifiable) high blood ldl cholesterol low blood hdl cholesterol high blood pressure (hypertension) diabetes obesity (especially abdominal obesity) physical inactivity cigarette smoking an atherogenic diet (high in saturated fats and low in vegetables, fruits, and whole grains) note: risk factors highlighted in color have relationships with diet. -source: expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel iii), third report of the national cholesterol education program (ncep), nih publication no. -02-5215 (bethesda, md. -: national heart, lung, and blood institute, 2002), pp. -ii-15 ii-20. -disease and strokes are the first and third leading causes of death, respectively, for adults in the united states. -risk factors for coronary heart disease although atherosclerosis can develop in any blood vessel, the coronary arteries are most often affected, leading to chd. -table 18-3 lists the major risk factors for chd. -the criteria for defining blood lipids, blood pressure, and obesity in relation to chd risk are shown in table 18-4; table h16-1 on p. 587 presents cholesterol stan- dards for children and adolescents. -by middle age, most adults have at least one risk factor for chd, and many have more than one.19 public health officials in both the united states and canada recommend screening to identify risk factors in individuals and offer preventive ad- vice for the population. -regular screening and early detection have proven success- ful: since 1960, both blood cholesterol levels and deaths from cardiovascular disease among u.s. adults have shown a continuous and substantial downward trend.20 these trends also reflect behavior changes in individuals. -as adults grow older, many of them stop smoking, limit alcohol consumption, and become mind- ful that their food choices can improve their cardiovascular health. -age, gender, and family history a review of table 18-3 shows that three of the major risk factors for chd cannot be modified by diet or otherwise: age, gender, and family history. -as men and women grow older, the risk of chd rises. -the increasing risk of chd with advancing age reflects the steady progression of atherosclerosis.21 on average, older people have more atherosclerosis than younger people do. -in men, aging becomes a significant risk factor at age 45 or older. -chd occurs about 10 to 15 years later in women than in men. -women younger than 45 tend to have lower ldl cholesterol than men of the same age, but women s blood choles- terol typically begins to rise between ages 45 and 55. thus aging becomes a signifi- cant risk factor for women who are 55 or older. -the gender difference has been attributed to a protective effect of estrogen in women, but chd rates do not suddenly accelerate at menopause as naturally-occurring estrogen levels taper off.22 rather, as in men, heart disease rates increase linearly with age. -and, as in men, all of the major risk factors raise the risk of chd in women. -ultimately, chd kills as many women as men and kills more women in the united states than any other disease. -nonetheless, at every age, men have a greater risk of chd than women do. -the reasons for this gender difference are not completely understood, but they can be partly explained by the earlier onset of risk factors such as elevated ldl cholesterol and blood pressure in men. -levels of the amino acid homocysteine, which may damage artery walls and increase oxidative stress, rise with age and are generally table 18-4 standards for chd risk factors risk factors total blood cholesterol (mg/dl) ldl cholesterol (mg/dl) hdl cholesterol (mg/dl) triglycerides, fasting (mg/dl) body mass index (bmi)d blood pressure (systolic and/or diastolic pressure) desirable borderline (cid:3)200 (cid:3)100a (cid:4)60 (cid:3)150 18.5 24.9 (cid:3)120/(cid:3)80 200 239 130 159 59 40 150 199 25 29.9 120 139/80 89e high risk (cid:4)240 160 189b (cid:3)40 200 499c (cid:4)30 (cid:4)140/(cid:4)90f a100 129 mg/dl ldl indicates a near or above optimal level. -b(cid:4)190 mg/dl ldl indicates a very high risk. -c(cid:4)500 md/dl triglycerides indicates a very high risk. -dbody mass index (bmi) was defined in chapter 8; bmi standards are found on the inside back cover. -ethese values indicate prehypertension. -f these values indicate stage one hypertension; (cid:4)160/(cid:4)100 indicates stage two hypertension. -physicians use these classifications to determine medical treatment. -higher in men. -researchers have not determined whether the damage is caused by homocysteine itself or by a factor associated with it.23 a history of early chd in immediate family members is an independent risk fac- tor even when other risk factors are considered. -the more family members affected and the earlier the age of onset, the greater the risk.24 high ldl and low hdl cholesterol in population studies, the relationship be- tween total blood cholesterol and atherosclerosis is strong and most of the total cholesterol is made up of ldl cholesterol. -the higher the ldl cholesterol, the greater the risk of chd. -the ldl are clearly the most atherogenic lipoproteins. -as chapter 5 explained, hdl also carry cholesterol, but raised hdl represents cholesterol returning from the cells to the liver and thus indicate a reduced risk of atherosclerosis and heart at- tack. -high ldl and low hdl correlate directly with heart disease, whereas low ldl and high hdl correlate inversely with risk. -any ldl cholesterol that remains in the blood after the body s cells take up the amount they need becomes vulnerable to oxidation. -high blood levels of ldl cho- lesterol, especially oxidized ldl, promote the development of fibrous plaques. -when the plaques weaken and become unstable, they can rupture, causing a heart attack. -evidence shows that elevated ldl contribute to plaque instability.25 in the early stages of atherosclerosis, the goal of treatment is to slow the development of plaque. -in the later stages, the goal of treatment is to stabilize plaques. -high blood pressure (hypertension) chronic high blood pressure (hyper- tension) frequently accompanies atherosclerosis, diabetes, and obesity. -the higher blood pressure is above normal, the greater the risk of heart disease. -however, even values only slightly higher than desirable classified as prehypertension in table 18-4 increases the risk of heart attack or stroke.26 this relationship between hyper- tension and heart disease risk holds true for men and women, young and old. -high blood pressure injures the artery walls and accelerates plaque formation, thus initi- ating or worsening the progression of atherosclerosis. -then the plaques and reduced blood flow raise blood pressure further, and hypertension and atherosclerosis be- come mutually aggravating conditions. -diabetes diabetes a major independent risk factor for all forms of cardiovascu- lar disease substantially increases the risk of death from chd.27 in diabetes, blood vessels often become blocked and circulation diminishes. -atherosclerosis progresses rapidly. -for many people with diabetes, the risk of chd is similar to that of people with established chd.28 in fact, physicians describe diabetes and other disorders that have risks similar to chd as chd risk equivalents. -treat- ment to lower ldl cholesterol in diabetes follows the same recommendations as in chd. -obesity and physical inactivity obesity, especially abdominal obesity, and physical inactivity significantly modify several of the risk factors for chd, contribut- ing to high ldl cholesterol, low hdl cholesterol, hypertension, and diabetes.29 con- versely, weight loss and physical activity protect against chd by lowering ldl, raising hdl, improving insulin sensitivity, and lowering blood pressure. -regular physical activity also increases energy expenditure and builds lean body mass, thereby improving body composition and physical fitness. -cigarette smoking cigarette smoking is a powerful risk factor for chd and other forms of cardiovascular disease. -the risk increases the more a person smokes and is the same for men and women. -smoking damages the heart directly by in- creasing blood pressure and the heart s workload. -it deprives the heart of oxygen and damages platelets, making blood clot formation likely. -toxins in cigarette smoke damage blood vessels, setting the stage for atherosclerosis. -when people quit smoking, their risk of chd declines within a few months.30 s e g a m i y t t e g / i x a t / s n i m m u c m i j atherogenic diet diet influences the risk of chd. -an atherogenic diet high in saturated fats, trans fat, and cholesterol and low in fruits and vegetables elevates diet and health 629 cholesterol is carried in several lipopro- teins, chief among them ldl and hdl (see chapter 5 for details). -remember them this way: ldl = low-density lipoproteins = less healthy hdl = high-density lipoproteins = healthy regular aerobic exercise can help to defend against heart disease by strengthening the heart muscle, promoting weight loss, and improving blood lipid and blood glucose levels. -630 chapter 18 reminder: insulin resistance is the condition in which a normal amount of insulin pro- duces a subnormal effect, resulting in an elevated fasting glucose; a metabolic conse- quence of obesity that precedes type 2 dia- betes. -the metabolic syndrome includes any three of the following: abdominal obesity: waist circumference (cid:5)40 in (for men) or (cid:5)35 in (for women) triglycerides: (cid:6)150 mg/dl hdl: (cid:3)40 mg/dl (in men) or (cid:3)50 mg/dl (in women) blood pressure: (cid:6)130/85 mm hg fasting glucose: (cid:6)100 mg/dl emerging risk factors: recently identified factors that enhance the ability to predict disease risk in an individual. -metabolic syndrome: a combination of risk factors insulin resistance, hypertension, abnormal blood lipids, and abdominal obesity that greatly increase a person s risk of developing coronary heart disease; also called syndrome x, insulin resistance syndrome, or dysmetabolic syndrome. -ldl cholesterol. -conversely, diets rich in fruits, vegetables, and whole grains seem to lower the risk of chd even more than might be expected based on risk factors such as ldl cholesterol alone. -the specific nutrients responsible for this benefit re- main to be defined, but some of the likely contenders include the antioxidant nu- trients and omega-3 fatty acids. -dietary strategies to reduce the risk of chd are discussed in a later section. -other risk factors the major risk factors for chd listed in table 18-3 and dis- cussed in the previous sections have solid associations with the development of chd. -nevertheless, other factors also seem to influence a person s risk of chd. -these factors, known as emerging risk factors, may be helpful in assessing an individual s risk of chd. -for example, some people with chd, especially those with diabetes and those who are overweight, have elevated triglycerides. -whether ele- vated blood triglycerides represent an independent risk factor for chd remains de- batable. -in the latest report by the national cholesterol education program expert panel, elevated blood triglycerides are considered a marker for other risk factors (high ldl, low hdl, overweight, and diabetes, for example), but they are not des- ignated as a major risk factor. -metabolic syndrome as table 18-3 shows, most of the modifiable risk factors for chd are directly related to diet. -several of these diet-related risk factors low hdl, high blood pressure, insulin resistance, and abdominal obesity along with high blood triglycerides comprise a cluster of health risks known as the metabolic syndrome. -metabolic syndrome predicts an increased risk of coro- nary heart disease, but no more so than when each risk factor is considered in- dividually.31 overeating and physical inactivity play a major role in the development of the metabolic syndrome. -based on the criteria listed in the mar- gin, about 47 million people in the united states have the metabolic syn- drome.32 a new definition of the metabolic syndrome has recently been proposed to include greater emphasis on central obesity.33 regardless of slight differences in defining metabolic syndrome, experts agree that the prevalence of metabolic syndrome among u.s. adults is high, and that treatment to reduce these risk factors for heart disease and diabetes should begin early and focus on changes in lifestyle. -recommendations for reducing coronary heart disease risk recommendations to reduce cardiovascular disease risk include both screening and intervention. -the accompanying how to provides a tool to assess a person s ten-year heart disease risk. -notice that total cholesterol and hdl cholesterol are included in the assessment, but ldl cholesterol is not. -ldl cholesterol is routinely estimated from measures of total cholesterol and hdl cholesterol and thus would not add information to this assessment.34 once a person s risks have been identi- fied, treatment focuses on lowering ldl cholesterol. -lowering ldl significantly re- duces the incidence of chd.35 treatment plans may include major lifestyle changes in diet, physical activity, and smoking cessation; medications; or both. -the ldl cholesterol goals and treatment plans are specific to individuals, so they are best prescribed by a qualified health care provider. -cholesterol screening to determine an individual s risk of chd, health care professionals review the person s health history and measure several blood lipids in- cluding total cholesterol, ldl cholesterol, hdl cholesterol, and triglycerides. -ideally, at least two measurements are taken at least one week apart and then compared to standards (shown earlier in table 18-4 on p. 628). -single measurements may fail to identify those at risk or may misclassify them because blood cholesterol and other lipid concentrations vary significantly from day to day. -diet and health 631 how to assess your risk of heart disease do you know your heart disease risk score? -this assessment estimates your ten-year risk for chd using charts from the framingham heart study. -* be aware that a high score does not mean that you will develop heart disease, but it should warn you of the possi- bility and prompt you to consult a physician about your health. -you will need to know your blood cholesterol (ideally, the average of at least two recent measurements) and blood pressure (ideally, the average of sev- eral recent measurements). -with this infor- mation in hand, find yourself in the five tables below and add the points for each risk factor. -age (years): hdl (mg/dl): systolic blood pressure (mm hg): men women men women untreated treated (cid:6)60 50 59 40 49 (cid:3)40 (cid:7)1 0 1 2 (cid:7)1 0 1 2 men women men women (cid:3)120 120 129 130 139 140 159 (cid:6)160 0 0 1 1 2 0 1 2 3 4 0 1 2 2 3 0 3 4 5 6 20 34 35 39 40 44 45 49 50 54 55 59 60 64 65 69 70 74 75 79 (cid:7)9 (cid:7)4 0 3 6 8 10 11 12 13 (cid:7)7 (cid:7)3 0 3 6 8 10 12 14 16 total cholesterol (mg/dl): age 20 39 age 40 49 age 50 59 age 60 69 age 70 79 men women men women men women men women men women (cid:3)160 160 199 200 239 240 279 (cid:6)280 0 4 7 9 11 0 4 8 11 13 0 3 5 6 8 0 3 6 8 10 0 2 3 4 5 smoking (any cigarette smoking in the past month): smoker nonsmoker 8 0 9 0 5 0 7 0 3 0 0 2 4 5 7 4 0 0 1 1 2 3 1 0 0 1 2 3 4 2 0 0 0 0 1 1 1 0 0 1 1 2 2 1 0 scoring your heart disease risk add up your total points: _______ . -now find your total in the first column for your gender in the table at the right and then look to the next column for your approximate risk of developing heart disease within the next ten years. -depending on your risk category, the following strategies can help reduce your risk: (cid:5)20% (cid:2) high risk (chd risk equivalent). -try to lower ldl using all lifestyle changes and, most likely, lipid-lowering medications as well. -10 20% (cid:2) moderate risk try to lower ldl using all lifestyle changes and, possibly, lipid-lowering medications. -(cid:3)10% (cid:2) low risk maintain or initiate lifestyle choices that help prevent elevation of ldl to prevent future heart disease. -men women total (cid:3)0 0 4 5 6 7 8 9 10 11 12 13 14 15 16 (cid:6)17 risk (cid:3)1% 1% 2% 3% 4% 5% 6% 8% 10% 12% 16% 20% 25% (cid:6)30% total (cid:3)9 9 12 13 14 15 16 17 18 19 20 21 22 23 24 (cid:6)25 risk (cid:3)1% 1% 2% 3% 4% 5% 6% 8% 11% 14% 17% 22% 27% (cid:6)30% *an electronic version of this assessment is available on the atp iii page of the national heart, lung, and blood institute s website (www.nhlbi.nih.gov/guidelines/cholesterol). -another risk inven- tory is available from the american heart association (www.americanheart.org). -source: adapted from expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (adult treatment panel iii), third report of the national cholesterol education program (ncep), nih publication no. -02-5216 (bethesda, md. -: national heart, lung, and blood institute, 2002), section iii. -lifestyle changes recommendations to reduce the risk of chd focus on lifestyle changes. -to that end, people are encouraged to increase physical activity, lose weight (if necessary), implement dietary changes, and reduce exposure to tobacco smoke either by quitting smoking or by avoiding secondhand smoke. -treatment plans for people with existing chd or conditions that place them at high risk for heart attacks and strokes (chd risk equivalents) also focus on lifestyle changes first, to assess your risk of heart disease, log on to www.thomsonedu.com/thomsonnow, go to chap- ter 18, then go to how to. -632 chapter 18 table 18-5 strategies to reduce risk of chd dietary strategies energy: balance energy intake and physical activity to prevent weight gain and to achieve or maintain a healthy body weight. -saturated fat, trans fat, and cholesterol: choose lean meats, vegetables, and low-fat milk products; minimize intake of hydrogenated fats. -limit saturated fats to less than 7% of total kcalories, trans fat to less than 1% of total kcalories, and cholesterol to less than 300 milligrams a day (see table h5-1). -soluble fibers: choose a diet rich in vegetables, fruits, whole grains, and other foods high in soluble fibers. -potassium and sodium: choose a diet high in potassium-rich fruits and vegetables, low-fat milk products, nuts and whole grains (see table 18-7). -choose and prepare foods with little or no salt (limit sodium intake to 2300 milligrams per day). -added sugars: minimize intake of beverages and foods with added sugars. -fish and omega-3 fatty acids: consume fatty fish rich in omega-3 fatty acids (salmon, tuna, sardines) at least twice a week. -plant sterols and stanols: consume food products that contain added plant sterols or stanols. -soy: consume soy foods to replace animal and dairy products that contain saturated fat and cholesterol. -alcohol: if alcohol is consumed, limit it to one drink daily for women and two drinks daily for men. -lifestyle choices physical activity: participate in at least 30 minutes of moderate-intensity endurance activity on most days of the week. -the eventual goal should be an expenditure of at least 2000 kcalories weekly. -smoking cessation: minimize exposure to any form of tobacco or tobacco smoke. -source: aha scientific statement: diet and lifestyle recommendations revision 2006, circulation 114 (2006) 82 96; f.m. -sacks and coauthors for the american heart association nutrition commit- tee, soy protein, isoflavones, and cardiovascular health, circulation 113 (2006): 1034 1044; expert panel on detection, evaluation, and treatment of high blood cholesterol in adults (adult treat- ment panel iii) third report of the national cholesterol education program (ncep), nih publication no. -02-5215 (bethesda, md. -: national heart, lung, and blood institute, 2002), p. v1 v28. -but their target ldl is lower. -altering one s lifestyle is challenging, and instruction and counseling are critical for success. -health professionals can explain the reasons for change, set obtainable goals, and offer practical suggestions. -if lifestyle changes fail to lower ldl or blood pressure to acceptable levels, then medications are pre- scribed. -table 18-5 summarizes strategies to reduce the risk of heart disease.36 the how to box on p. 633 offers suggestions for implementing a heart-healthy diet. -in summary atherosclerosis is characterized by a buildup of plaque in an artery wall. -rup- ture of plaque or abnormal blood clotting can cause heart attacks and strokes. -dietary recommendations to lower the risks of cardiovascular disease are sum- marized in table 18-5. quitting smoking and engaging in regular physical ac- tivity also improve heart health. -hypertension anyone concerned about atherosclerosis and the risk it presents must also be con- cerned about hypertension. -together, the two are a life-threatening combination. -the higher the blood pressure is above normal, the greater the risk. -(low blood pres- sure, on the other hand, is generally a sign of long life expectancy and low heart dis- ease risk.) -hypertension affects at least 65 million people in the united states, about a third of the adult population.37 it contributes to over a million heart attacks and half a million strokes each year. -in fact, hypertension is the most consistent and powerful predictor of stroke.38 people cannot feel the physical effects of high blood pressure, but it can impair life s quality and end life prematurely. -how hypertension develops the underlying causes of most cases of hypertension are not fully understood, but much is known about the physiological factors that affect blood pressure. -as shown y r e g a m i k c o t s x e d n i / r e l l e k l e a h c i m to guard against hypertension, have your blood pressure checked regularly. -diet and health 633 how to implement a heart-healthy diet following a heart-healthy diet can require major changes in dietary choices. -people may find it easier to adopt a new diet if only a few changes are made at a time. -it also helps to focus on positive choices (what to eat) first, rather than negative ones (what not to eat). -breads, cereals, and pasta choose whole-grain breads and cereals. -make sure the first ingredient on bread and cereal labels is whole wheat rather than enriched wheat flour. -bakery products often contain trans-fatty acids. -choose foods whose labels do not list any trans fat in the nutrition facts panel or hydro- genated oil in the ingredients list. -crackers, chips, cookies, and doughnuts often include trans fats. -avoid products that contain tropical oils (coconut, palm, and palm kernel oil), which are high in saturated fat. -fruits and vegetables consume fruits and vegetables frequently. -keeping the refrigerator stocked with a variety of colorful fruits and vegetables (baby carrots, grapes, blueberries, melon) makes it easier to choose healthy foods when the urge to nibble arises. -incorporate at least one or two servings of fruits and vegetables into each meal. -people who rarely eat fruits or vegetables may start by adding at least one of their favorites to each meal. -choose canned products carefully. -canned vegetables (especially tomato-based products) may be high in sodium. -fruits that are canned in juice are higher in nutrient density than those canned in syrup. -restrict high-sodium foods such as pickles, olives, sauerkraut, and kimchee. -avoid french fries from fast-food restaurants, which are often loaded with trans fats. -lunch and dinner entr es limit meat, fish, and poultry servings to a maximum intake of 5 ounces per day. -select lean cuts of beef, such as sirloin tip, round steak, and arm roast, and lean cuts of pork, such as center-cut ham, loin chops, and tender- loin. -trim visible fat before cooking. -select extra-lean ground meat and drain well after cooking. -use lean ground turkey, without skin added, in place of ground beef. -limit cholesterol-rich organ meats (liver, brain, sweetbreads). -limit egg yolks to no more than two per week because the yolks are high in cholesterol (about 215 milligrams per yolk). -replace whole eggs in recipes with egg whites or commercial egg substitutes or similar reduced-cholesterol products. -include more vegetarian entr es or legume dishes to boost soluble fiber and soy protein intakes. -pasta and stir-fry recipes can help to reduce meat intake and increase vegetables in the diet. -restrict these high-sodium foods: cured or smoked meats such as beef jerky, bologna, corned or chipped beef, frankfurters, ham, luncheon meats, salt pork, and sausage salty or smoked fish, such as anchovies, caviar, salted or dried cod, herring, sardines, and smoked salmon packaged, canned, or frozen soups, sauces, and entr es milk products milk products can be good sources of protein, calcium, vitamin d, and potassium. -to obtain two to three servings daily, include a portion of fat-free or low-fat milk, yogurt, or cottage cheese in each meal. -use yogurt or fat-free sour cream to make dips or salad dressings. -substitute evaporated fat-free milk for heavy cream. -restrict foods high in saturated fat or sodium, such as cheese, processed cheeses, ice cream, and many other milk-based desserts. -fats and oils add nuts (not salted) and avocados to meals to increase monounsatu- rated fat intakes and make meals more appetizing. -include vegetable oils in salad dressings and recipes, such as canola, corn, olive, peanut, safflower, sesame, soybean, and sunflower oils. -use margarines with added plant sterols or stanols regularly to lower ldl cholesterol levels. -select soft margarines in tubs or liquid form; they have few, if any, trans fats. -avoid stick margarines and solid vegetable shortenings. -avoid products that contain tropical oils (coconut, palm, and palm kernel oil), which are high in saturated fat. -spices and seasonings use salt only at the end of cooking, and you will need to add much less. -use salt substitutes at the table. -spices and herbs improve the flavor of foods without adding sodium. -try using more garlic, ginger, basil, curry or chili powder, cumin, pepper, lemon, mint, oregano, rosemary, and thyme. -check the sodium content on labels. -flavorings and sauces that are usually high in sodium include bouillon cubes, soy sauce, steak and barbecue sauces, relishes, mustard, and catsup. -snacks and desserts select low-sodium and low saturated fat choices such as unsalted pretzels and nuts, plain popcorn, and unsalted chips and crackers. -choose canned or dried fruits and some raw vegetables to boost fruit and vegetable intake. -enjoy angel food cake, which is made without egg yolks and added fat. -select low-fat frozen desserts such as sherbet, sorbet, fruit bars, and some low-fat ice creams in figure 18-4 (p. 634), blood pressure arises from the contractions in heart muscle that pump blood away from the heart (cardiac output) and the resistance blood encounters in the arterioles (peripheral resistance). -when either cardiac output or peripheral resistance increases, blood pressure rises. -cardiac output is raised when heart rate or blood volume increases; peripheral resistance is affected mostly reminder: cardiac output is the volume of blood discharged by the heart each minute. -the equation describing this relationship is blood pressure = cardiac output (cid:8) peripheral resistance. -peripheral resistance: the resistance to pumped blood in the small arterial branches (arterioles) that carry blood to tissues. -634 chapter 18 figure 18-4 determinants of blood pressure cardiac output is the volume of blood pumped by the heart within a specified period of time. -peripheral resistance refers to the resistance to pumped blood by the small arterial branches (arterioles) that carry blood to tissues. -by the diameters of the arterioles. -blood pressure is therefore influenced by the nerv- ous system, which regulates heart muscle contractions and the arteriole s diameters, and hormonal signals, which may cause fluid retention or blood vessel constriction. -the kidneys also play a role in regulating blood pressure by controlling the secretion of the hormones involved in vasoconstriction and retention of sodium and water.39 risk factors for hypertension several major risk factors predicting the development of hypertension have been identified, including: aging. -hypertension risk increases with age. -individuals who have normal blood pressure at age 55 still have a 90 percent risk of developing high blood pressure during their lifetimes.40 genetics. -hypertension risk is similar among family members. -it is also more prevalent and severe in certain ethnic groups: for african americans in the united states, the prevalence of high blood pressure is among the highest in diet and health 635 blood pressure is measured in millimeters of mercury (mm hg). -blood pressure is measured both when the heart muscle con- tracts (systolic blood pressure) and when it relaxes (diastolic blood pressure). -the optimal resting blood pressure for adults is (cid:3)120 over (cid:3)80 mm hg. -for adults 40 to 70 years of age, each increase of 20 mm hg in systolic, or 10 mm hg in dias- tolic, blood pressure doubles the risk of cardiovascular disease. -the world.41 compared with whites, african americans develop high blood pressure earlier in life and their average blood pressure is much higher. -obesity. -most people with hypertension an estimated 60 percent are obese.42 obesity raises blood pressure in part by altering kidney function, promoting insulin resistance which damages blood vessels, and increasing blood volume and cardiac output without an appropriate reduction in pe- ripheral resistance.43 salt sensitivity. -among those with hypertension, approximately 30 to 50 per- cent have blood pressure that is sensitive to salt and can benefit by reducing salt in their diets.44 alcohol. -alcohol consumption, especially if consumed regularly in amounts greater than two drinks per day, is strongly associated with hypertension. -al- cohol may interfere with drug therapy and is associated with strokes inde- pendently of hypertension. -treatment of hypertension the single most effective step people can take against hypertension is to find out whether they have it. -at checkup time, a health care professional can provide an ac- curate resting blood pressure reading. -under normal conditions, blood pressure fluctuates continuously in response to a variety of factors including stress and such actions as talking or shifting position. -some people react emotionally to the proce- dure, which raises the blood pressure reading. -for these reasons, if the resting blood pressure is above normal, the reading should be repeated before confirming the diagnosis of hypertension. -thereafter, the blood pressure should be checked regu- larly. -both lifestyle modifications and drug therapies are used to treat hypertension. -table 18-6 describes the lifestyle changes that reduce blood pressure and the ex- pected reduction in systolic blood pressure for each change. -weight control efforts to reduce high blood pressure focus on weight control. -weight loss alone is one of the most effective nondrug treatments for hypertension. -those who are using drugs to control their blood pressure can often reduce or discon- tinue the drugs if they lose weight. -even a modest weight loss of 10 pounds can lower blood pressure significantly. -table 18-6 lifestyle modifications to reduce blood pressure modification recommendation expected reduction in systolic blood pressure weight reduction maintain healthy body weight (bmi below 25). -5 20 mm hg/10 kg lost dash eating plan sodium restriction physical activity moderate alcohol consumption adopt a diet rich in fruits, vegetables, and low- fat milk products with reduced saturated fat intake. -reduce dietary sodium intake to less than 2400 milligrams sodium (less than 6 grams salt) per day. -* 8 14 mm hg 2 8 mm hg perform aerobic physical activity for at least 30 minutes per day, most days of the week. -4 9 mm hg men: limit to 2 drinks per day. -2 4 mm hg women and lighter-weight men: limit to 1 drink per day. -*according to the dietary guidelines and dri recommendations, sodium intake should be limited to 2300 milligrams daily. -source: adapted from reference card from the seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure (jnc 7), nih publication no. -03-5231 (bethesda, md. -: national institutes of health, national heart, lung, and blood institute, and national high blood pressure education program, may 2003). -636 chapter 18 like other low-fat diets, the dash diet also lowers hdl a seemingly undesirable out- come. -whether a lowered hdl raises the risk of chd is unknown, although some studies suggest that people with both low ldl and low hdl do not have an increased risk of chd. -the richest sources of potassium are fresh foods of all kinds. -physical activity the higher the blood pressure and the less active a person is to begin with, the greater the effect physical activity has in reducing blood pressure. -physical activity helps with weight control, of course, but moderate aerobic activity, such as 30 to 60 minutes of brisk walking most days, also helps to lower blood pres- sure directly. -those who engage in regular aerobic activity may not need medication for mild hypertension. -the dash diet the results of the dietary approaches to stop hypertension (dash) trial show that a diet rich in fruits, vegetables, nuts, and low-fat milk prod- ucts and low in total fat and saturated fat can significantly lower blood pressure. -the dash eating plan provides more fiber, potassium, magnesium, and calcium than the typical american diet, which helps to reduce blood pressure. -the diet also limits red meat, sweets, and sugar-containing beverages. -table 18-7 shows that the dash eating plan is similar to the usda food guide (introduced in chapter 2). -both eating plans meet the goals specified in the dietary guidelines for ameri- cans 2005.45 when the dash diet is combined with a limited intake of sodium, the effects on blood pressure are greater still.46 in addition to lowering blood pressure, the dash diet lowers total cholesterol and ldl cholesterol.47 thus the heart-healthy dietary guidelines embrace these strategies in an overall diet to prevent and treat chd. -for many years, controversy surrounded recommendations to restrict sodium or salt, but strong evidence supports the important role this strategy plays in prevent- ing and reducing hypertension. -lowering sodium intake reduces blood pressure re- gardless of gender or race, presence or absence of preexisting hypertension, or whether people follow the dash diet or a typical american diet. -furthermore, the lower the sodium intake, the greater the drop in blood pressure. -(see the box in chapter 12 on p. 411 for suggestions about limiting sodium intake.) -dietary guidelines for americans 2005 individuals with hypertension, blacks, and middle-aged and older adults should aim to consume no more than 1500 mg of sodium per day and to meet the potassium recommendation (4700 mg/day) with food. -drug therapy when diet and physical activity fail to reduce blood pressure, di- uretics and antihypertensive agents may be prescribed. -diuretics lower blood pres- sure by increasing fluid loss. -some diuretics can lead to a potassium deficiency. -people taking these diuretics need to include rich sources of potassium or supple- ments daily and watch for signs of potassium imbalances such as weakness (partic- ularly of the legs), unexplained numbness or tingling sensation, cramps, irregular heartbeats, and excessive thirst and urination. -blood potassium should be moni- tored regularly. -table 18-7 the dash eating plan and the usda food guide compared s e g a m i r e t i p u j / y r e g a m i k c o t s x e d n i / g r e b l l a h n a f e t s food group dash usda food guide grains vegetables fruits milk (fat-free/low-fat) lean meats, poultry, fish nuts, seeds, legumes 6 8 oz 2 21/2 c 2 21/2 c 2 3 c 6 oz or less 4 5 oz per week 6 oz 21/2 c 2 c 3 c 51/2 oz a note: these diet plans are based on 2000 kcalories per day. -both dash and the usda food guide recommend that fats and sugars be used sparingly and with discretion. -a the usda food guide combines nuts, seeds, and legumes with meat, poultry, and fish. -diet and health 637 although some diuretics can lead to a potassium deficiency, others spare potas- sium. -a combination of these two types of diuretics may be prescribed to prevent potassium deficiency. -figure 18-5 prevalence of diabetes among adults in the united states in summary the most effective dietary strategy for preventing hypertension is weight con- trol. -also beneficial are diets rich in fruits, vegetables, nuts, and low-fat milk products and low in fat, saturated fat, and sodium. -key: missing data (cid:3)4% 4% 4.9% 5% 5.9% (cid:6)6% diabetes mellitus the incidence of diabetes among children and adults has risen dramatically in the last decade (see figure 18-5). -it now affects more than 20 million people in the united states.48 more than 6 million of those affected do not know they have the dis- ease a danger because damage to the body occurs before symptoms develop. -diabetes mellitus ranks sixth among the leading causes of death (review figure 18-2 on p. 624). -in addition, diabetes underlies, or contributes to, several other ma- jor diseases, including heart disease, stroke, blindness, and kidney failure. -heart dis- ease is the leading cause of diabetes-related deaths. -in fact, people with diabetes are twice as likely to develop these cardiovascular problems as those without diabetes. -how diabetes develops diabetes mellitus describes a group of metabolic disorders characterized by high blood glucose concentrations and disordered insulin metabolism. -people with dia- betes may have insufficient insulin, ineffective insulin, or a combination of the two. -the result is hyperglycemia, a marked elevation in blood glucose that can ulti- mately cause damage to blood vessels, nerves, and tissues. -as many as 41 million u. s. adults between the ages of 40 and 74 have prediabetes their blood glucose is elevated but not to such an extent as to be classified as diabetes. -people with prediabetes have a high risk of developing diabetes. -the accompanying glossary defines diabetes, and table 18-8 (p. 638) shows the distinguishing features of its two main forms, type 1 diabetes and type 2 diabetes. -as described in the next section, the development of type 1 and type 2 diabetes dif- fers, but some of the complications are similar. -to appreciate the problems presented by an absolute or relative lack of insulin, consider insulin s normal action. -after a meal, insulin signals the body s cells to re- ceive the energy nutrients from the blood amino acids, glucose, and fatty acids. -in- sulin helps to maintain blood glucose within normal limits and stimulates protein synthesis, glycogen synthesis in liver and muscle, and fat synthesis. -without insulin, glucose regulation falters, and metabolism of the energy-yielding nutrients changes. -1994: 14 states had a prevalence of diabetes of less than 4% and only two states had a prevalence of 6% or greater. -2004: no state had a prevalence of diabetes of less than 4%, and 39 states had a prevalence of 6% or greater. -source: centers for disease control and prevention, www.cdc.gov/nccdphp/aag/aag_ddt.htm. -fasting blood glucose normal: (cid:3) 100 mg/dl prediabetes: 100 125 mg/dl diabetes: (cid:6)125 mg/dl hyperglycemia: elevated blood glucose concentrations. -g lossary of diabetes terms diabetes (dye-uh-beet-eez) mellitus (mell-ih-tus or mell- eye-tus): a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. -mellitus = honey-sweet (sugar in urine) prediabetes: condition in which blood glucose levels are higher than normal but not high enough to be diagnosed as diabetes; considered a major risk factor for future diabetes and cardiovascular diseases; formerly called impaired glucose tolerance. -type 1 diabetes: the type of type 2 diabetes: the type of diabetes that accounts for 5 to 10% of diabetes cases and usually results from autoimmune destruction of pancreatic beta cells. -in this type of diabetes, the pancreas produces little or no insulin. -diabetes that accounts for 90 to 95% of diabetes cases and usually results from insulin resistance coupled with insufficient insulin secretion. -obesity is present in 80 to 90% of cases. -638 chapter 18 autoimmune disorder: a condition in which the body develops antibodies to its own proteins and then proceeds to destroy cells containing these proteins. -in type 1 diabetes, the body develops antibodies to its insulin and destroys the pancreatic cells that produce the insulin, creating an insulin deficiency. -table 18-8 features of type 1 and type 2 diabetes prevelence in diabetic population age of onset associated conditions major defect insulin secretion requirement for insulin therapy older names type 1 type 2 5 10% of cases <30 years autoimmune diseases, viral infections, inherited factors destruction of pancreatic beta cells; insulin deficiency little or none always juvenile-onset diabetes insulin-dependent diabetes mellitus (iddm) 90 95% of cases >40 yearsa obesity, aging, inherited factors insulin resistance; insulin deficiency (relative to needs) varies; may be normal, increased, or decreased sometimes adult-onset diabetes noninsulin-dependent diabetes mellitus (niddm) a incidence of type 2 diabetes is increasing in children and adolescence; in more than 90 percent of these cases, it is associ- ated with overweight or obesity and a family history of type 2 diabetes. -type 1 diabetes in type 1 diabetes, the less common type of diabetes (about 5 to 10 percent of all diagnosed cases), the pancreas loses its ability to synthesize the hormone insulin. -type 1 diabetes is an autoimmune disorder.49 in most cases, the individual inherits a defect in which immune cells mistakenly attack and de- stroy the insulin-producing beta cells of the pancreas. -the rate of beta cell destruc- tion in type 1 diabetes varies. -in some people (mainly infants and children), destruction is rapid; in others (mainly adults), it is slow. -type 1 diabetes commonly occurs in childhood and adolescence, but it can occur at any age, even late in life.50 without insulin, the body s energy metabolism changes, with such severe conse- quences as to threaten survival. -the cells must have insulin to take up the needed fuels from the blood. -people with type 1 diabetes must inject insulin or use external pumps; insulin cannot be taken orally because it is a protein, and the enzymes of the gi tract would digest it. -type 2 diabetes type 2 diabetes is the most prevalent form of diabetes, ac- counting for 90 to 95 percent of cases, and is often asymptomatic.51 the primary de- fect in type 2 diabetes is insulin resistance, a reduced sensitivity to insulin in muscle, adipose, and liver cells. -to compensate, the pancreas secretes larger amounts of in- sulin, and plasma insulin concentrations can rise to abnormally high levels (hyper- insulinemia). -over time, the pancreas becomes less able to compensate for the cells reduced sensitivity to insulin, and hyperglycemia worsens. -the high demand for in- sulin can eventually exhaust the beta cells of the pancreas and lead to impaired in- sulin secretion and reduced plasma insulin concentrations. -type 2 diabetes is therefore associated both with insulin resistance and with relative insulin deficiency; that is, the amount of insulin is insufficient to compensate for its diminished effect in cells. -although the actual causes of type 2 diabetes are unknown, the risk is substan- tially increased by obesity (especially abdominal obesity), aging, and physical in- activity. -most people with type 2 diabetes are obese, and obesity itself can directly cause some degree of insulin resistance.52 as discussed in highlight 16, obesity has led to a dramatic rise in the incidence of type 2 diabetes among children and ado- lescents during the past two decades.53 inherited factors also strongly influence risk, and type 2 diabetes is more common in certain ethnic populations, including na- tive americans, hispanic americans, mexican americans, african americans, asian americans, and pacific islanders. -diet and health 639 complications of diabetes in both types of diabetes, glucose fails to gain entry into the cells and conse- quently accumulates in the blood. -these two problems lead to both acute and chronic complications. -figure 18-6 summarizes the metabolic changes and acute complications that can arise in uncontrolled diabetes. -notice that when some glu- cose enters the cells, as in type 2 diabetes, many of the symptoms of type 1 do not occur. -over the long term, the person with diabetes suffers not only from the acute complications shown in figure 18-6, but also from its chronic effects. -chronically elevated blood glucose alters glucose metabolism in virtually every cell of the body. -some cells begin to convert excess glucose to sugar alcohols, for example, causing toxicity and cell distention distended cells in the lenses of the eyes, for example, cause blurry vision. -some cells produce glycoproteins by attaching ex- cess glucose to an amino acid in a protein; the altered proteins cannot function normally, which leads to a host of other problems. -the structures of the blood ves- sels and nerves become damaged, leading to loss of circulation and nerve func- tion. -infections occur due to poor circulation coupled with glucose-rich blood and figure 18-6 metabolic consequences of untreated diabetes the metabolic consequences of type 1 diabetes differ from those of type 2. in type 1, no insulin is available to allow any glucose to enter the cells. -when glucose cannot enter the cells, a cascade of metabolic changes quickly follows. -in type 2 diabetes, some glucose enters the cells. -because the cells are not starved for glucose, the body does not shift into the metabolism of fasting (losing weight and producing ketones). -type 1 no glucose enters the cells blood glucose rises (hyper- glycemia) type 2 some glucose enters the cells, but slowly cells break down protein and fat hunger glucose spills into the urine (glycosuria) water moves into the blood (osmotic effect) hunger ketones produced for energy (ketosis) weight loss frequent urination (polyuria) and fluid losses excessive eating (polyphagia) diabetic ketoacidosis manifested by: (cid:129) ketones in the breath (acetone breath) (cid:129) ketones in the blood (ketonemia) (cid:129) ketones in the urine (ketonuria) excessive eating (polyphagia) diabetic coma (can be fatal) ahyperosmolar hyperglycemic state usually develops in the absence of ketosis and is most often associated with type 2 diabetes. -weight gain dehydration (blood volume depletion and electrolyte imbalances) and excessive thirst (polydipsia) hyperosmolar hyperglycemic state or comaa (can be fatal) 640 chapter 18 disorders of the small blood vessels are called microangiopathies. -micro = small angeion = vessel pathos = disease the death of tissue, usually due to deficient blood supply, is gangrene (gang-green). -urine. -people with diabetes must pay special attention to hygiene and keep alert for early signs of infection. -early, aggressive treatment to control blood glucose sig- nificantly reduces the risk of long-term diabetes-related complications. -diseases of the large blood vessels as mentioned, atherosclerosis tends to develop early, progress rapidly, and be more severe in people with diabetes. -the in- terrelationships among insulin resistance, obesity, hypertension, and atherosclerosis help explain why about 75 percent of people with diabetes die as a consequence of cardiovascular diseases, especially heart attacks. -research shows that intensive dia- betes treatment, which keeps blood glucose levels tightly controlled, can reduce the risk of cardiovascular disease among those with type 1 diabetes.54 diseases of the small blood vessels for people with diabetes, disorders of the small blood vessels (capillaries) may also develop and lead to loss of kidney func- tion and retinal degeneration with accompanying loss of vision. -about 85 percent of people with diabetes have impaired kidney function, loss of vision, or both. -con- sequently, diabetes is a leading cause of both kidney failure and blindness. -diseases of the nerves nerve tissues may also deteriorate with diabetes, ex- pressed at first as a painful prickling sensation, often in the arms and legs. -later, the person loses sensation in the hands and feet. -injuries to these areas may go unno- ticed, and infections can progress rapidly. -with loss of both circulation and nerve function, undetected injury and infection may lead to death of tissue (gangrene), necessitating amputation of the limbs (most often the legs or feet). -people with diabetes are advised to take conscientious care of their feet and visit a podiatrist regularly. -recommendations for diabetes diet is an important component of diabetes treatment. -to maintain near-normal blood glucose levels, the diet is designed to deliver the same amount of carbohydrate each day, spaced evenly throughout the day. -several approaches can be used to plan such diets, but many people with diabetes learn to count carbohydrates using the exchange system that is presented in appendix g (appendix i for canadians). -total carbohydrate intake providing a consistent carbohydrate intake spaced throughout the day helps people with diabetes maintain appropriate blood glucose levels and maximizes the effectiveness of drug therapy. -eating too much carbohydrate at one time can raise blood glucose too high, stressing the already-compromised insulin-producing cells. -eating too little carbohydrate can lead to abnormally low blood sugar (hypoglycemia). -the amount of carbohy- drate affects blood glucose levels more than the source of the carbohydrate.55 low carbohydrate diets (less than 130 grams of carbohydrate per day) are not recommended. -56 carbohydrate sources different carbohydrate-containing foods have varying effects on blood glucose levels; for example, consuming a portion of white rice may cause blood glucose to rise higher and quicker than would a similar portion of barley. -as chapter 4 described, this glycemic effect of foods is influenced by a food s fiber content, the preparation method, the other foods included in a meal, and individual tolerances. -at present, the glycemic effect of individual foods is not a primary consideration when treating diabetes, as there has not been enough ev- idence to suggest a long-term benefit when only foods with a low glycemic effect are consumed.57 however, as for the general population, people with diabetes should derive at least half of their grain intake from high-fiber, whole-grain prod- ucts that have more moderate effects on blood glucose than do highly processed starchy foods. -a common misconception is that people with diabetes need to avoid sugar and sugar-containing foods. -because moderate consumption of sugar has not been diet and health 641 reminder: one drink is equivalent to 12 ounces of beer, 5 ounces of wine, 10 ounces of wine cooler, or 11/2 ounces of 80 proof distilled spirits such as gin, rum, vodka, and whiskey. -shown to adversely affect glycemic control, however, sugar recommendations for people with diabetes are similar to those for the general population, which suggests choosing foods and beverages with little added sugars. -sugars and sugary foods must be counted as part of the daily carbohydrate allowance, however. -dietary fat as mentioned earlier, people with diabetes have a high risk of devel- oping cardiovascular diseases, and their guidelines for dietary fat are similar to those for others with high risks. -saturated fat intake should be limited to less than 7 percent of kcalories and cholesterol intake to less than 200 milligrams daily.58 di- etary strategies for cardiovascular disease were discussed earlier in this chapter. -protein protein intakes in the united states generally range from 15 to 20 percent of total kcalories. -protein intakes in this range need not be modified for individuals with diabetes and normal kidney function.59 higher protein intakes are discouraged because they may be detrimental to kidney function. -alcohol use in diabetes adults with diabetes can drink alcohol in moderation. -guidelines are similar to those for the general population, which advise a daily limit of one drink for women and two drinks for men.60 recommendations for type 1 diabetes normally, the body secretes a con- stant baseline amount of insulin at all times and secretes more as blood glucose rises following meals. -people with type 1 diabetes, however, produce little or no insulin. -they must learn to adjust the amount and schedule of their insulin doses to accom- modate meals, physical activity, and health status. -to maintain blood glucose within a fairly normal range requires a lifelong commitment to a carefully coordi- nated program of diet, physical activity, and insulin. -nutrition therapy for type 1 diabetes focuses on maintaining optimal nutrition status, controlling blood glucose, achieving a desirable blood lipid profile, control- ling blood pressure, and preventing and treating the complications of diabetes. -in addition to meeting basic nutrient requirements, the diet must provide a fairly consistent carbohydrate intake from day to day and at each meal and snack to help minimize fluctuations in blood glucose. -further alterations in diet may be necessary for the person with chronic complications such as cardiovascular or kid- ney disease. -participation in all levels of physical activity is possible for people with type 1 diabetes who have good blood glucose control and no complications, but they should check with their physician first. -one potential problem is hypoglycemia, which can occur during, immediately after, or many hours after physical activ- ity.61 to avoid hypoglycemia, the person must monitor blood glucose before and after activity to identify when changes in insulin or food intake are needed. -carbohydrate-rich foods should be readily available during and after activity. -recommendations for type 2 diabetes in overweight people with type 2 dia- betes, even moderate weight loss (10 to 20 pounds) can help improve insulin resist- ance, blood lipids, and blood pressure. -together with diet, a regular routine of moderate physical activity not only supports weight loss, but also improves blood glucose control, blood lipid profiles, and blood pressure. -thus the benefits of regular, long-term physical activity for the treatment and prevention of type 2 diabetes are substantial.62 in summary diabetes is characterized by high blood glucose and either insufficient insulin, ineffective insulin, or a combination of the two. -people with type 1 diabetes co- ordinate diet, insulin injections, and physical activity to help control their blood glucose. -those with type 2 benefit most from a diet and physical activ- ity program that controls glucose fluctuations and promotes weight loss. -e i w o d n n a for a person with type 1 diabetes, good health depends on coordinating the timing of meals, activities, and insulin. -642 chapter 18 an abnormal mass of cells that is non- cancerous is called a benign tumor. -cancer cancer, the growth of malignant tissue, ranks just below cardiovascular disease as a cause of death in the united states. -(see the accompanying glossary of cancer terms.) -as with cardiovascular disease, the prognosis for cancer today is far brighter than in the past. -identification of risk factors, new detection techniques, and inno- vative therapies offer hope and encouragement. -cancer is not a single disorder. -there are many cancers, that is, many different kinds of malignant growths. -they have different characteristics, occur in different locations in the body, take different courses, and require different treatments. -how cancer develops the development of cancer, called carcinogenesis, often proceeds slowly and con- tinues for several decades. -a cancer arises from mutations in the genes that control cell division in a single cell. -these mutations may promote cellular growth, interfere with growth restraint, or prevent cellular death.63 the affected cell thereby loses its built-in capacity for halting cell division, and it produces daughter cells with the same genetic defects. -as the abnormal mass of cells, called a tumor, grows, a net- work of blood vessels develop to supply the tumor with the nutrients it needs to sup- port its growth. -the tumor can disrupt the functioning of the normal tissue around it, and some tumor cells may metastasize, or spread to another region in the body. -figure 18-7 illustrates cancer development. -in leukemia (cancer affecting the white blood cells) the cells do not form a tumor, but rather accumulate in blood and other tissues. -the reasons cancers develop are numerous and varied. -vulnerability to cancer is sometimes inherited, as when a person is born with a genetic defect that alters dna structure, function, or repair. -certain metabolic processes may initiate car- cinogenesis, as when phagocytes (immune cells) produce oxidants that cause dna damage or when chronic inflammation enhances the rate of cell division, which increases the risk of a damaging mutation. -more often, cancers are caused by inter- actions between a person s genes and the environment. -exposure to cancer-causing substances, or carcinogens, may either induce genetic mutations that lead to cancer or promote proliferation of cancerous cells. -environmental factors among environmental factors, exposure to radiation and sun, water and air pollution, and smoking are known to cause cancer. -lack of g lossary of cancer terms antipromoters: factors that oppose the development of cancer. -cancers: malignant growths or tumors that result from abnormal and uncontrolled cell division. -carcinogenesis (car-sin-oh-jen- eh-sis): the process of cancer development. -carcinogens (car-sin-oh-jenz or car-sin-oh-jenz): substances that can cause cancer (the adjective is carcinogenic). -carcin = cancer gen = gives rise to initiators: factors that cause mutations that give rise to cancer, such as radiation and carcinogens. -tumor: an abnormal tissue mass with no physiological function; also called a neoplasm (nee-oh- plazm). -malignant (ma-lig-nant): cancers are classified by the describes a cancerous cell or tumor, which can injure healthy tissue and spread cancer to other regions of the body. -metastasize (me-tas-tah-size): the spread of cancer from one part of the body to another. -promoters: factors that favor the development of cancers once they have begun. -tissues or cells from which they develop: adenomas (add-eh-noh- mahz): cancers that arise from glandular tissues. -carcinomas (kar-see-noh- mahz): cancers that arise from epithelial tissues. -gliomas (gly-oh-mahz): can- cers that arise from glial cells of the central nervous system. -leukemias (loo-kee-mee-ahz): cancers that arise from white blood cell precursors. -lymphomas (lim-foh-mahz): cancers that arise from lymph tissue. -melanomas (mel-ah-noh- mahz): cancers that arise from pigmented skin cells. -sarcomas (sar-koh-mahz): cancers that arise from con- nective tissues, such as muscle or bone. -figure 18-7 cancer development diet and health 643 malignant cells normal cells initiation promotion further tumor development normal cells mutagens alter the dna in a cell and induce abnormal cell division. -promoters enhance the development of abnormal cells, resulting in formation of a tumor. -the cancerous tumor releases cells into the bloodstream or lymphatic system (metastasis). -physical activity may also play a role in the development of some types of cancer.64 men and women whose lifestyles include regular, vigorous physical activity have the lowest risk of colon cancer.65 physical activity may also protect against breast cancer by reducing body weight and by other mechanisms not related to body weight.66 obesity itself is clearly a risk factor for certain types of cancer (such as colon, breast in postmenopausal women, endometrial, kidney, and esophageal) and pos- sibly for other types (such as ovarian and prostate) as well.67 because different can- cers have various causes, the way obesity influences cancer development depends on the site as well as other factors, such as hormonal interactions. -in the case of breast cancer in postmenopausal women, for example, the hormone estrogen is implicated. -obese postmenopausal women have much higher levels of estrogen than lean women do because fat tissue produces estrogen. -researchers believe that the extended exposure to estrogen in obese women is linked to an increased risk of breast cancer after menopause.68 the relationships between excessive body weight and certain cancers provide yet another reason to adopt a lifestyle that embraces physical activity and sound nutrition. -as table 18-9 (p. 644) shows, dietary constituents are also associated with an in- creased risk of certain cancers. -some dietary factors may initiate cancer develop- ment (initiators), others may promote cancer development once it has started (promoters), and still others may protect against the development of cancer (antipromoters). -s k r o w e g a m i e h t / s i e r i e m t n e k dietary factors cancer initiators we do not know to what extent diet con- tributes to cancer development, although some experts estimate that diet may be linked to as many as a third of all cases. -consequently, many people think that cer- tain foods are carcinogenic, especially those that contain additives or pesticides. -as chapter 19 explains, our food supply is one of the safest in the world. -additives that have been approved for use in foods are not carcinogens. -some pesticides are car- cinogenic at high doses, but not at the concentrations allowed on fruits and vegeta- bles. -the benefits of eating fruits and vegetables are far greater than any potential risk. -cancers of the head and neck correlate strongly with the combination of alco- hol and tobacco use and with low intakes of green and yellow fruits and vegetables. -alcohol intake alone is associated with cancers of the mouth, throat, and breast, and alcoholism often damages the liver and precedes the development of liver can- cer.69 these findings illustrate clearly why any potential benefit of moderate alco- hol consumption on cardiovascular disease must be weighed against the potential dangers. -people with cancer take comfort from the sup- port of others and from the knowledge that medical science is waging an unrelenting battle in their defense. -644 chapter 18 table 18-9 factors associated with cancer at specific sites cancer sites bladder cancer breast cancer associated with: probable protective effect from: cigarette smoking and alcohol; weak association with coffee and chlorinated drinking water high intakes of food energy, alcohol intake; low vitamin a intake; obesity, sedentary lifestyle, probably high saturated fat intake; possibly high sucrose intake fruits and vegetables (especially fruits); adequate fluid intake monounsaturated fats; vegetables and fruits; physical activity cervical cancer folate deficiency; viral infection; possibly, cigarette smoking adequate folate intake; possibly, fruits and vegetables colorectal cancer kidney cancer mouth, throat, and esophagus cancers liver cancer lung cancer ovarian cancer pancreatic cancer prostate cancer stomach cancer high intakes of fat (particularly saturated fat), red meat, alcohol, and supplemental iron; low intakes of fiber, folate, vitamin d, and vegetables; inactivity; cigarette smoking vegetables, especially cruciferous (cabbage-type) vegetables; fruits; calcium, vitamin d, and dairy intake; possibly, whole wheat; wheat bran; high levels of physical activity possibly, high intakes of red meat (especially fried, saut ed, charred, burned, or cooked well-done); cigarette smoking; obesity heavy use of alcohol, tobacco, and especially combined use; heavy use of preserved foods (such as pickles); low intakes of vitamins and minerals; obesity (esophageal) infection with hepatitis virus; high intakes of alcohol; iron overload; toxins of a mold (aflatoxin) or other toxicity smoking; low vitamin a; supplements of beta-carotene (in smokers); air pollution possibly, high lactose intake from milk products; inversely correlated with oral contraceptive use possibly, high intakes of red meat; physical inactivity; correlated with cigarette smoking and air pollution fruit and vegetables, especially orange-colored and dark green ones fruits and vegetables vegetables, especially yellow and green ones fruits and vegetables vegetables, especially green leafy ones fruits and vegetables, especially green and yellow ones high intakes of fats, especially saturated fats from red meats and possibly milk products possibly, cooked tomatoes, soybeans, soy products, and flaxseed; adequate selenium intake high intakes of smoke- or salt-preserved foods (such as dried, salted fish); cigarette smoking; possibly, refined flour or starch; infection with ulcer-causing bacteria fresh fruits and vegetables, especially tomatoes sources: american cancer society, the complete guide to nutrition and physical activity, available at: www.cancer.org/docroot/ped/content/ped_3_2x_diet_and_activity_factors _that_affect_risks.asp?sitearea=ped; m. pavia and coauthors, association between fruit and vegetable consumption and oral cancer: a meta-analysis of observational studies, american journal of clinical nutrition 83 (2006): 1126 1134; a. flood and coauthors, calcium from diet and supplements is associated with reduced risk of colorectal cancer in a prospective cohort of women, cancer epidemiology, biomarkers and prevention 14 (2005): 126 132; l. bernstein and coauthors, lifetime recreational exercise activity and breast cancer risk among black women and white women, journal of the national cancer institute 97 (2005): 1671 1679; m. d. holmes and w. c. willett, does diet affect breast cancer risk? -breast cancer research 6 (2004): 170 178; i. romieu and coauthors, carbohydrates and the risk of breast cancer among mexican women, cancer epidemiology, biomarkers and prevention 13 (2004): 1283 1289; c. e. spiegelman and coauthors, premenopausal fat intake and risk of breast cancer, journal of the national cancer institute 95 (2003): 1079-1085; national cancer policy board, institute of medicine, s. j. curry, t. byers, and m. hewitt, eds., fulfilling the potential of cancer prevention and early detection (washing- ton, d.c.: national academies press, 2003), pp. -66 86; s. e. mccann and coauthors, risk of human ovarian cancer is related to dietary intake of selected nutrients, phytochemicals and food groups, journal of nutrition 133 (2003): 1937 1942. to minimize carcinogen formation during cooking: when grilling, line the grill with foil, or wrap the food in foil. -take care not to burn foods. -marinate meats beforehand. -grilling meat, fish, or other foods over a direct flame causes fat and added oils to splash on the fire and then vaporize, creating carcinogens that rise and stick to the food. -* eating grilled food introduces these carcinogens to the digestive system, where they may damage the stomach and intestinal lining. -once these compounds are absorbed into the blood, however, they are detoxified by the liver. -evidence from population studies spanning the globe for over 20 years supports the theory that diets high in meat, especially red meat, are related to a moderately elevated risk of developing colon cancer.70 in particular, meats cooked to the crispy well-done stage may be responsible.71 remember, however, that even strong corre- lation is not causation certain foods may be implicated, but they have not been proven to actually cause cancer. -nevertheless, replacing most servings of red meat with poultry, fish, or legumes and choosing only occasional servings of grilled, fried, highly browned, or smoked foods is in the best interest of health. -another reason to moderate consumption of fried foods such as french fries and potato chips is the presence of a substance called acrylamide, which is a potential * the carcinogens of greatest concern are heterocyclicamines and benzopyrene. -carcinogen. -acrylamide is produced when certain starches such as potatoes are fried or baked at high temperatures. -chapter 19 offers a discussion of acrylamide in foods. -dietary factors cancer promoters unlike carcinogens, which initiate can- cers, some dietary components promote cancers. -that is, once the initiating step has taken place, these components may accelerate tumor development. -studies of animals suggest that high-fat diets may promote cancer, but in stud- ies of human beings, evidence is mixed.72 one attribute of dietary fat is energy den- sity gram for gram, fat provides more kcalories than either carbohydrate or protein. -diets high in kcalories do seem to promote cancer, especially in laboratory settings. -the type of fat in the diet may influence cancer promotion or prevention. -some evidence implicates saturated and trans-fatty acids in cancer promotion and suggests that omega-3 fatty acids from fish may protect against some can- cers.73 thus the same dietary fat advice applies to cancer protection as to heart health: reduce saturated and trans-fatty acids and increase omega-3 fatty acids. -dietary factors antipromoters some foods may contain antipromoters dietary compounds that defend against cancer. -research on dietary patterns of populations has identified such foods and led to recommendations aimed at reduc- ing cancer risks. -recommendations for reducing cancer risk almost without exception, epidemiological studies find a link between eating plenty of fruits and vegetables and a low incidence of cancers. -fruits and vegetables con- tain both nutrients and phytochemicals with antioxidant activity, and these sub- stances may prevent or reduce the oxidative reactions in cells that cause dna damage. -phytochemicals may also help to inhibit carcinogen production in the body, enhance immune functions that protect against cancer development, and promote enzyme reactions that inactivate carcinogens.74 for example, the crucif- erous vegetables cabbage, cauliflower, broccoli, and brussels sprouts contain a variety of phytochemicals that have proven beneficial in defending against colon cancer. -in addition, fruits and vegetables, as well as legumes and whole-grains, are rich in fiber. -as chapter 4 explained, fiber may protect against cancer by binding, dilut- ing, and rapidly removing potential carcinogens from the gi tract. -high-fiber and whole-grain foods also help a person to maintain a healthy body weight another preventive measure against cancer. -physical activity also helps to maintain a healthy body weight and reduce the risks of some cancers. -table 18-10 (p. 646) summarizes dietary and lifestyle recommendations for reducing cancer risk. -in summary some dietary factors, such as alcohol and heavily smoked foods, may initiate cancer development; others, such as saturated fat or trans-fatty acids, may pro- mote cancer once it has gotten started; and still others, such as fiber, antioxi- dant nutrients, and phytochemicals, may serve as antipromoters that protect against the development of cancer. -by eating many fruits, vegetables, legumes, and whole grains and reducing saturated and trans fat intake, people obtain the best possible nutrition at the lowest possible risk. -minimizing weight gain through regular physical activity and a healthy diet is also beneficial. -diet and health 645 . -c n i s o i d u t s a r a l o p cruciferous vegetables, such as cauliflower, broccoli, and brussels sprouts, contain nutrients and phytochemicals that may inhibit cancer development. -cruciferous vegetables: vegetables of the cabbage family, including cauliflower, broccoli, and brussels sprouts. -646 chapter 18 a summary of the diet, nutrition, and pre- vention of chronic diseases report from the world health organization (who) is pre- sented in appendix i. table 18-10 recommendations for reducing cancer risk healthy body weight: choose foods that help maintain a healthy weight throughout life. -choose foods low in energy, fat, and sugar. -eat small portions of high-kcalorie, high-fat, or high-sugar foods. -balance energy intake with physical activity. -lose weight if currently overweight or obese. -variety: eat a variety of healthful foods, with an emphasis on plant sources. -vegetables and fruits: eat 5 or more servings of a variety of vegetables and fruits each day. -include vegetables and fruits at every meal and for snacks. -limit fried vegetables. -if you drink juices, choose 100% fruit or vegetable juices. -whole grains: choose whole grains (such as oats and whole wheat bread) instead of refined grains (such as sweetened cereals and pastries) and sugars (such as soft drinks and candies). -meats: limit consumption of red meats, especially those high in fat and processed. -choose fish, poultry, and legumes as alternatives to beef, pork, and lamb. -select lean cuts and small portions. -bake, broil, or poach instead of frying or charbroiling. -alcohol: if you drink alcoholic beverages, limit consumption to no more than 2 drinks a day for men and 1 drink a day for women. -physical activity: adopt a healthy active lifestyle. -engage in at least moderate activity for 30 minutes or more on 5 or more days of the week (45 minutes or more of moderate to vigorous activity on 5 or more days per week may further reduce the risk of breast and colon cancers). -source: l. h. kushi and coauthors, american cancer society guidelines on nutrition and physical activity for cancer preven- tion: reducing the risk of cancer with healthy food choices and physical activity, ca: a cancer journal for clinicians 56 (2006): 254 281, available at http://caonline.amcancersoc.org/cgi/content/full/56/5/254. -recommendations for chronic diseases this chapter s discussion of chronic diseases began with the major cardiovascular diseases, described diabetes, and then went on to cancer three different condi- tions with distinct sets of causes. -yet dietary excesses, particularly excess food en- ergy and fat intakes, increase the likelihood of all three diseases.75 similarly, all are responsive to diet, and in most cases, the beneficial foods are similar. -not all diet recommendations apply equally to all of the diseases or to all peo- ple with a particular disease, but fortunately for the consumer, dietary recommen- dations do not contradict one another. -in fact, they support each other. -most people can gain some disease-prevention benefits by making dietary changes. -to that end, the recommendations of the american heart association (table 18-5), the dash diet (table 18-7), and the recommendations for reducing cancer risk (table 18-10) describe the kinds of foods people should include or limit. -table 18-11 com- pares the dietary guidelines for americans 2005 with these recommendations for chronic diseases. -several recommendations are aimed at weight control. -obesity is common in the united states, and it is linked with most of the chronic diseases that threaten life (review figure 18-3 on p. 625). -the problems of overweight people multiply when medical conditions develop. -for example, overweight people readily develop dia- betes, which is often accompanied by high blood pressure and high blood choles- terol. -such a combination of problems may require only one treatment: adopting a healthful diet and regular exercise program. -diet and health 647 table 18-11 dietary guidelines and recommendations for chronic diseases compared dietary guidelines heart disease hypertension diabetes cancer maintain a healthy body weight. -engage in regular physical activity. -keep total fat 20 35%. -limit saturated and trans fats. -select fiber-rich fruits, vegetables, and whole grains. -use little sugar. -use little salt. -drink alcohol in moderation. -dietary guidelines for americans 2005 to reduce the risk of chronic disease in adulthood, engage in at least 30 minutes of moderately intense physical activity, above usual activity, at work or at home on most days of the week. -for most people, greater health benefits can be obtained by engaging in physical activity of more vigorous intensity or longer duration. -recommendations for the population the recommendations to prevent chronic diseases address the general population in the hope that all people at all levels of risk may benefit. -such a strategy is similar to national efforts to vaccinate to prevent measles, fluoridate water to prevent dental caries, and fortify grains with folate to prevent neural tube defects. -recommendations for individuals people s hereditary susceptibility to dis- eases and their responsiveness to dietary measures vary. -unlike nutrient-deficiency diseases, which develop when nutrients are lacking and disappear when the nutri- ents are provided, chronic diseases are neither caused nor prevented by diet alone. -many people have followed dietary advice and developed heart disease or cancer anyway; others have ignored all advice and lived long and healthy lives. -for many people, though, diet does influence the time of onset and course of some chronic dis- eases, and many health care professionals urge dietary measures as part of a dis- ease-prevention strategy. -to determine whether dietary recommendations are important to you person- ally, look at your family history to see which diseases are common to your relatives. -in addition, examine your personal history, taking note of your blood pressure, blood lipid profile, and lifestyle habits such as smoking and physical activity. -recommendations for each individual even when recommendations are made for individuals, they apply to large groups of people those with hyperten- sion or those with diabetes, for example. -but that s expected to change in the next decade or so as research on the human genome provides the knowledge needed to create specific recommendations for each individual (as highlight 6 explains).76 in summary clearly, optimal nutrition plays a key role in keeping people healthy and re- ducing the risk of chronic diseases. -to have the greatest impact possible, di- etary recommendations are aimed at the entire population, not just at the individuals who might benefit most. -recommendations focus on weight con- trol and urge people to limit saturated and trans fat, increase fiber-rich carbo- hydrates, and balance food intake with physical activity. -a person can do no better than to incorporate those suggestions into his or her daily life. -recommendations that urge all people to make dietary changes believed to forestall or prevent diseases are taking a preventive or population approach. -alternatively, recom- mendations that urge dietary changes only for people who are known to need them are taking a medical or individual approach. -reminder: the full complement of genetic material (dna) in the chromosomes of a cell is called genome. -in human beings, the genome consists of 46 chromosomes. -the study of genomes is called genomics. -s e g a m i y t t e g / e n o t s / s e r y a e c u r b physical activity and a moderate weight loss of even 10 to 20 pounds can help improve blood glucose, blood lipids, and blood pressure. -648 chapter 18 www.thomsonedu.com/thomsonnow nutrition portfolio identifying your risk factors is the first step in taking action to defend yourself against heart attack, stroke, hypertension, diabetes, and cancer. -review your personal and family history of heart disease, hypertension, diabetes, and cancer. -consider whether you are sedentary or overweight and how you might become more physically active and achieve a healthy body weight. -if you smoke ciga- rettes, develop a reasonable plan for quitting. -learn whether you have high blood cholesterol or high blood pressure. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 18, then to nutrition on the net. -find aids information at the office of aids research: www.oar.nih.gov learn about hiv infections: www.hivpositive.com review resources offered by the national center for chronic disease prevention and health promotion: www.cdc.gov/nccdphp find information on health at the nih consumer health information site: health.nih.gov visit the national health information center site: www.health.gov find information about health statistics at the national center for health statistics site: www.cdc.gov/nchs examine your family s health history at the u.s. surgeon general s site: familyhistory.hhs.gov study questions search for chronic diseases, disease prevention, men s health, women s health, heart disease, stroke, high blood pressure, cancer, and diabetes at the u.s. gov- ernment site: www.healthfinder.gov learn about women s health from the national women s health information center site: www.4women.gov review the surgeon general s reports on physical activity and health and reducing tobacco use: www .surgeongeneral.gov/library assess your heart disease risk at the american heart asso- ciation site: www.americanheart.org visit the national stroke association: www.stroke.org find information on the dash diet: dashdiet.org visit the national heart, lung, and blood institute site and click on clinical practice guidelines for cholesterol and hypertension guidelines: www.nhlbi.nih.gov/ index.htm to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -4. describe some steps that people with hypertension can take to lower their blood pressure. -(pp. -635 636) these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. how do the major diseases of today as a group differ from those of several decades ago as a group? -why is nutrition considered so important in connection with today s major diseases? -(pp. -621, 624 625) 2. identify the major diet-related risk factors for atheroscle- rosis, hypertension, diabetes, and cancer. -(p. 625) 3. describe some ways in which people can alter their diets to lower their blood cholesterol levels. -(pp. -630 632) 5. name the two major types of diabetes and describe some differences between them. -how do dietary recommenda- tions for diabetes compare with the healthy diet recom- mended for all people? -(pp. -637 641) 6. differentiate between cancer initiators, promoters, and antipromoters. -which nutrients or foods fit into each of these categories? -(pp. -643 645) 7. describe the characteristics of a diet that might offer the best protection against the onset of cancer. -(p. 646) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 651. -1. the immune cells of the body do not include: a. b-cells. -b. t-cells. -c. antigens. -d. phagocytes. -2. which of the following produce antibodies? -a. phagocytes b. t-cells c. antigens d. b-cells 3. the leading cause of death in the united states is: a. aids. -b. cancer. -c. diabetes. -d. heart disease. -4. plaques in the arteries contribute to the development of: a. cancer. -b. diabetes. -c. atherosclerosis. -d. infectious diseases. -diet and health 649 6. moderate amounts of alcohol may protect against heart disease by: a. promoting ldl oxidation. -b. preventing clot formation. -c. raising ldl and lowering hdl. -d. accelerating plaque formation. -7. what is the most effective strategy for most people to lower their blood pressure? -a. lose weight b. restrict salt c. monitor glucose d. supplement protein 8. complications of diabetes may include all of the follow- ing except: a. blurry vision. -b. nerve damge. -c. impaired circulation. -d. osteoporosis. -9. the most important dietary strategy in diabetes is to: a. provide for a consistent carbohydrate intake. -b. restrict fat to 30 percent of daily kcalories. -c. limit carbohydrate intake to 300 milligrams a day. -d. take multiple vitamin and mineral 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activity and colorectal cancer, sports medicine 34 (2004): 239-252; y. mao and coauthors, physical inactivity, energy intake, obesity and the risk of rectal cancer in canada, international journal of cancer 105 (2003): 831-837; a. s. furberg and i. thune, metabolic abnormalities (hypertension, hyperglycemia and over- weight) lifestyle (high energy intake and physical inactivity) and endometrial cancer risk in a norwegian cohort, international journal of cancer 104 (2003): 669-676; e. giovannucci, diet, body weight, and col- orectal cancer: a summary of the epidemio- logic evidence, journal of women s health 12 (2003): 173-182. answers study questions (multiple choice) 1. c 2. d 3. d 4. c 5. b 6. b 7. a 8. d 9. a 10. c highlight 18 complementary and alternative medicine if you suffered from migraine headaches or severe joint pain, where would you turn for relief? -would you visit a physician? -or are you more likely to go to an herbalist or an acupuncturist? -most physi- cians diagnose and treat medical conditions in ways that are accepted by the established med- ical community; herbalists and acupuncturists, among others, offer alternatives to standard med- ical practice. -instead of taking two aspirin, for ex- ample, you might be advised to chew two fresh leaves of the herb feverfew or to swallow a tincture of white willow bark. -or you might receive a massage and several acupuncture needles. -complementary and alternative medicine (cam) has become increasingly popular in recent decades (see the glossary below for this and related terms).1 people use these therapies for a variety of reasons. -some want to take more responsibility for both maintaining their own health and finding cures for their own diseases, especially when traditional medical therapies prove ineffective. -others have become distrustful of, and feel over- whelmed by, the high-tech diagnostic tests and costly treatments that conventional medicine offers. -this highlight explores al- ternative therapies in search of their possible benefits and with an awareness of their potential harms. -defining complementary and alternative medicine by definition, complementary and alternative medicine is not conventional medicine. -it includes a variety of approaches, philosophies, and treatments, some of which are defined in the glossary of alternative therapies on the next page. -when these therapies are used instead of conventional medicine, they are s e g a m i y t t e g / i x a t / a c o e d s e t n o m called alternative; when used together with conventional medicine, they are called comple- mentary. -t r a a growing number of health care profes- sionals are learning about alternative thera- pies; half of u.s. medical schools now offer elective courses in alternative medicine, and even more include discussions of these thera- pies in their required courses. -by incorporat- ing some of the beneficial alternative therapies into their practices, an approach called integrative medicine, health care professionals take advantage of the best of both kinds of medicine.2 to best serve their clients, these health care profes- sionals provide balanced advice, guard against bias, and main- tain trusting relationships.3 for some alternative therapies, preliminary and limited scien- tific evidence suggests some effectiveness; but for most, well- designed scientific studies have yet to determine safety and effec- tiveness. -if proved safe and effective, an alternative therapy may be adopted by conventional medicine. -cancer radiation therapy, for example, was once considered an unconventional therapy, but it proved its clinical value and became part of accepted med- ical practice. -in some cases, a therapy that is accepted by conven- tional medicine for a specific ailment is used for a different purpose in an alternative therapy. -for example, chelation therapy, the preferred medical treatment for lead poisoning, is a common alternative therapy for cardiovascular disease. -sound research, loud controversy much information on alternative therapies comes from folklore, tradition, and testimonial accounts. -relatively few clinical trials g lossary complementary and alternative medicine (cam): diverse medical and health care systems, practices, and products that are not currently considered part of conventional medicine; also called adjunctive, unconventional, or unorthodox therapies. -complementary medicine: an approach that uses alternative therapies as an adjunct to, and not simply a replacement for, conventional medicine. -conventional medicine: diagnosis and treatment of diseases as practiced by medical doctors (m.d.) -and doctors of osteopathy (d.o.) -and allied health professionals such as physical therapists and registered nurses; also called allopathy; western, mainstream, orthodox, or regular medicine; and biomedicine. -integrative medicine: an approach that incorporates alternative therapies into the practice of conventional medicine (similar to complementary medicine, but a closer relationship is implied). -652 complementary and alternative medicine 653 g lossary of alternative therapies acupuncture (ak-you-punk- cher): a technique that involves piercing the skin with long thin needles at specific anatomical points to relieve pain or illness. -acupuncture sometimes uses heat, pressure, friction, suction, or electromagnetic energy to stimulate the points. -aroma therapy: a technique that uses oil extracts from plants and flowers (usually applied by massage or baths) to enhance physical, psychological, and spiritual health. -ayurveda (ah-your-vay-dah): a traditional hindu system of improving health by using herbs, diet, meditation, massage, and yoga to stimulate the body, mind, and spirit to prevent and treat disease. -bioelectromagnetic medical applications: the use of electrical energy, magnetic energy, or both to stimulate bone repair, wound healing, and tissue regeneration. -biofeedback: the use of special devices to convey information about heart rate, blood pressure, skin temperature, muscle relaxation, and the like to enable a person to learn how to consciously control these medically important functions. -biofield therapeutics: a manual healing method that directs a healing force from an outside source (commonly god or another supernatural being) through the practitioner and into the client s body; commonly known as laying on of hands. -cartilage therapy: the use of cleaned and powdered connective tissue, such as collagen, to improve health. -chelation (kee-lay-shun) therapy: the use of ethylene diamine tetraacetic acid (edta) to bind with metallic ions, thus healing the body by removing toxic metals. -chiropractic (kye-roh-prak-tik): a manual healing method of manipulating the spine to restore health. -faith healing: healing by invoking divine intervention without the use of medical, surgical, or other traditional therapy. -herbal (erb-al) medicine: the use of plants to treat disease or improve health; also known as botanical medicine or phytotherapy. -homeopathy (hoh-me-op-ah- thee): a practice based on the theory that like cures like, that is, that substances that cause symptoms in healthy people can cure those symptoms when given in very dilute amounts. -homeo (cid:2) like pathos (cid:2) suffering hydrotherapy: the use of water (in whirlpools, as douches, or packed as ice, for example) to promote relaxation and healing. -hypnotherapy: a technique that uses hypnosis and the power of suggestion to improve health behaviors, relieve pain, and heal. -imagery: a technique that guides clients to achieve a desired physical, emotional, or spiritual state by visualizing themselves in that state. -iridology: the study of changes in the iris of the eye and their relationships to disease. -macrobiotic diets: extremely restrictive diets limited to a few grains and vegetables; based on metaphysical beliefs and not nutrition. -a macrobiotic diet might consist of brown rice, miso soup, and sea vegetables, for example. -massage therapy: a healing method in which the therapist manually kneads muscles to reduce tension, increase blood circulation, improve joint mobility, and promote healing of injuries. -meditation: a self-directed technique of relaxing the body and calming the mind. -naturopathic (nay-chur-oh-path- ick) medicine: a system that taps the natural healing forces within the body by integrating several practices, including traditional medicine, herbal medicine, clinical nutrition, homeopathy, acupuncture, east asian medicine, hydrotherapy, and manipulative therapy. -orthomolecular medicine: the use of large doses of vitamins to treat chronic disease. -ozone therapy: the use of ozone gas to enhance the body s immune system. -qi gong (ch e gung): a chinese system that combines movement, meditation, and breathing techniques to enhance the flow of qi (vital energy) in the body. -have been conducted. -consequently, scientific evidence proving the safety and effectiveness of many alternative therapies is lacking. -some say that alternative therapies simply do not work; others sug- gest that these therapies have not been given a fair trial. -in an effort to explore complementary and alternative healing practices through vigorous science, the national center for complementary and alternative medicine supports clinical trials of these therapies. -ar- ticles reporting the results of these clinical trials are available online in a subset of pubmed created specifically for scientifically based, peer- reviewed journals on complementary and alternative therapies. -sound research would answer two important questions. -first, does the treatment offer better results than either doing nothing or giving a placebo? -second, do the benefits clearly outweigh the risks? -each of these points is worthy of elaboration. -placebo effect stories abound that credit alternative therapies with miraculous cures. -without scientific research to determine effectiveness, however, one is left to wonder whether it is the therapies or the placebo effect that produces the cure. -recall from chapter 1 that giving a placebo often brings about a healing effect in people who believe they are receiving the treatment. -traditional medi- cine tends to neglect this powerful remedy, whereas many alter- native therapies embrace it. -risks versus benefits ideally, a therapy provides benefits with little or no risk. -figure h18-1 (p. 654) presents several examples of herbal remedies that appear to be generally safe and possibly effective in treating various condi- tions.4 such findings, if replicated, hold promise that these alternative therapies may one day be integrated into conventional medicine. -some alternative therapies are innocuous, providing little or no benefit for little or no risk. -sipping a cup of warm tea with a pleasant aroma, for example, won t cure heart disease, but it may improve one s mood and help relieve tension. -given no physical hazard and little financial risk, such therapies are acceptable. -in contrast, other products and procedures are downright dan- gerous, posing great risks while providing no benefits. -one example is the folk practice of geophagia (eating earth or clay), which can cause gi impaction and impair iron absorption. -another is the tak- ing of laetrile to treat cancer, which can cause cyanide poisoning. -clearly, such therapies are too harmful to be used. -654 highlight 18 figure h18-1 examples of herbal remedies y m a l a / n o s l i w e u s ginger may relieve nausea and vomiting due to motion sickness or pregnancy. -ginkgo may slow the loss of cognitive function associated with age. -st. john s wort may be effective in treating mild depression. ) -s r e h t o l l a ( s e g a m i y t t e g / e m i t / l l e r r o w s e m a j american ginseng may improve glucose control in people with type 2 diabetes. -saw palmetto may improve the symptoms associated with an enlarged prostate. -the gel of an aloe vera plant soothes a minor burn. -perhaps most controversial are alternative therapies that may provide benefits, but also carry significant, unknown, or debatable risks. -smoking marijuana is an example of such an alternative therapy.5 the compounds in marijuana seem to provide relief from symptoms such as nausea, vomiting, and pain that commonly accompany cancer, aids, and other diseases, but marijuana use also pose risks that some people, including many physicians, con- sider acceptable whereas others, mainly politicians, deem intolera- ble. -physicians have focused on individuals and recognize that marijuana stimulates the appetite in their nauseated clients; politi- cians and others have focused on society and realize that marijuana is one of many drugs that can be abused. -figure h18-2 (p. 655) summarizes the relationships between risks and benefits. -nutrition-related alternative therapies most alternative therapies fall outside the field of nutrition, but nutrition itself can be an alternative therapy. -furthermore, many alternative therapies prescribe specific dietary regimens even though most practitioners are not registered dietitians (see high- light 1). -nutrition-related alternative therapies include the use of foods, vitamin and mineral supplements, and herbs to prevent and treat illnesses. -figure h18-2 risk-benefit relationships still remain clearly in the realm of complementary and alter- native medicine. -complementary and alternative medicine 655 no (or little) risk much ideal situation benefits with little or no risk. -(accept) cautionary situation possible benefits with great or unknown risks. -(consider carefully) neutral situation little or no benefit with little or no risk. -(accept or reject as preferred) dangerous situation no benefits with great risks. -(reject) h c u m i t f e n e b ) e l t t i l r o ( o n foods the many dietary recommendations presented throughout this text are based on scientific evidence and do not fall into the alter- native therapies category; strategies that are still experimental, however, do. -for example, alternative therapists may recommend macrobiotic diets to help prevent chronic diseases, whereas most registered dietitians would advise people to eat a balanced diet that includes four to five cups of fresh vegetables and fruits daily. -similarly, enough scientific evidence is available to recommend including soy foods in the diet to protect against heart disease but not to determine whether the phytoestrogens of soy are safe or beneficial in managing the symptoms of menopause. -highlight 13 explored the potential health benefits of soy and many other functional foods and concluded that no one food is magical. -as part of a balanced diet, these foods can support good health and protect against disease. -importantly, the benefits de- rive from a variety of foods. -more research is needed to determine the safety and effectiveness of taking supplements of the phyto- chemicals found in these foods. -vitamin and mineral supplements like foods, vitamin and mineral supplements may fall into either the conventional or the alternative realm of medicine. -for exam- ple, conventional advice recommends consuming 400 micro- grams of folate to prevent neural tube defects, but not the taking of 1000 milligrams of vitamin c to prevent the common cold. -highlight 10 examined the appropriate use of supplements and potential dangers of excessive intakes. -as research on nutrition and chronic diseases has revealed many of the roles played by the vitamins and minerals in support- ing health, conventional medicine has warmed up to the possibil- ity that vitamin and mineral supplements might be an appropriate preventive therapy.6 some vitamin and mineral supplements ap- pear to be in transition from alternative medicine to conventional medicine; that is, they have begun to prove their safety and effec- tiveness. -table h18-1 (p. 656) includes several nutrition-related therapies among those recognized to slow the progression of cancer and treat related symptoms. -herbal remedies, however, herbal remedies from earliest times, people have used myriad herbs and other plants to cure aches and ills with varying degrees of success (review figure h18-1). -upon scientific study, dozens of these folk remedies reveal their secrets. -for example, myrrh, a plant resin used as a painkiller in ancient times, does indeed have an analgesic effect. -the herb valerian, which has long been used as a tranquilizer, contains oils that have a sedative effect. -senna leaves, brewed as a laxative tea, pro- duce compounds that act as a potent cathartic drug. -green tea, brewed from the dried leaves of camellia sinensis, con- tains phytochemicals that induce cancer cells to self-destruct. -naturally occurring salicylates provide the same protective effects as low doses of aspirin. -salicylates are found in spices such as curry, paprika, and thyme; fruits; vegetables; teas; and candies fla- vored with wintergreen (methylsalicylate). -beneficial compounds from wild species contribute to about half of our modern medicines. -by analyzing these compounds, pharmaceutical labs can synthesize pure forms of the drugs. -un- like herbs and wild species, which vary from batch to batch, syn- thesized medicines deliver exact dosages. -by synthesizing drugs, we are also able to conserve endangered species. -consider that it took all of the bark from one 40-foot-tall, 100-year-old pacific yew tree to produce one 300-milligram dose of the anticancer drug paclitaxel (taxol), until scientists learned how to synthesize it. -many yet undiscovered cures may be forever lost as wild species are destroyed, long before their secrets are revealed to medicine. -s e g a m i y t t e g / e n o t s / n i l u g l l e r r a d digoxin, the most commonly prescribed heart medication, derives from the leaves of the foxglove plant (digitalis purpurea). -656 highlight 18 table h18-1 advice and precautions on alternative therapies for cancer and related conditions therapy precautions accept/consider recommending evidence supports effectiveness and safety. -vitamin e (for prostate cancer) not appropriate for people with a low platelet count; those taking anticoagulant medications; or those undergoing radiation, chemotherapy, or surgery acupuncture (for nausea and vomiting) not appropriate for people with a low platelet count or those taking anticoagulant medications massage (for anxiety, nausea, and lymph drainage) not appropriate directly over tumors, stents, or prosthetic devices and in areas damaged by surgery or radiation; or in people with bleeding abnormalities accept evidence supports safety, but inconclusive on effectiveness. -low-fat diet (for breast and prostate cancer) not appropriate for people with poor nutrition status macrobiotic dieta vitamin e (for some cancers) soy (for prostate cancer) mind-body therapies acupuncture (for chronic pain) massage (for pain) not appropriate for people with poor nutrition status or those who have breast or endometrial cancer not appropriate for people with a low platelet count; those taking anticoagulant medications; or those undergoing radiation, chemotherapy, or surgery not appropriate for people with a low platelet count or those taking anticoagulant medications or undergoing surgery not appropriate for people who do not have reasonable expectations not appropriate for people with a low platelet count or those taking anticoagulant medications not appropriate directly over tumors, stents, or prosthetic devices and in areas damaged by surgery or radiation; or in people with bleeding abnormalities discourage evidence indicates either ineffectiveness or serious risk. -vitamin a supplements (both retinols and carotenoid precursors) may increase the incidence of cancer in high-risk populations vitamin c supplements may have anticoagulant effects soy (for breast or endometrial cancer) may stimulate tumor growth and inhibit platelet aggregation note: alternative therapies may be appropriate as an adjunct to, not a replacement of, conven- tional treatment; physicians need to monitor progress and revise recommendations as needed. -awhen carefully planned, macrobiotic diets can provide adequate nutrition, little fat, and abundant phytoestrogens from soy. -restrictive macrobiotic diets, however, can cause malnutrition. -source: adapted from w. a. weiger and coauthors, advising patients who seek complementary and alternative medical therapies for cancer, annals of internal medicine 137 (2002): 889 903. herbal precautions plants are natural, but that does not mean all plants are benefi- cial or even safe. -nothing could be more natural and deadly than the poisonous herb hemlock. -several herbal remedies have toxic effects. -the popular chinese herbal potion jin bu huan, which is used as a pain and insomnia remedy, has been linked with several cases of acute hepatitis. -germanium, a nonessential mineral commonly found in many herbal products, has been as- sociated with chronic kidney failure. -paraguay tea produces symptoms of agitation, confusion, flushed skin, and fever. -kom- bucha tea, commonly used in the hopes of preventing cancer, re- lieving arthritis, curing insomnia, and stimulating hair regrowth, can cause severe metabolic acidosis. -table h18-2 lists selected herbs, their common uses, and risks.7 although some people use herbs to treat or prevent disease, herbs are not regulated as drugs; they are considered dietary sup- plements. -the food and drug administration (fda) does not evaluate dietary supplements for safety or effectiveness, nor does it monitor their contents. -under the dietary supplement health and education act, rather than the herb manufacturers having to prove the safety of their products, the fda has the burden of proving that a product is not safe. -consequently, consumers may lack information about or find discrepancies regarding: true identification of herbs. -most mint teas are safe, for in- stance, but some varieties contain the highly toxic pennyroyal oil. -mistakenly used to soothe a colicky baby, mint tea laden with pennyroyal has been blamed for the liver and neurolog- ical injuries of at least two infants, one of whom died. -purity of herbal preparations. -a young child diagnosed with lead poisoning had taken an herbal vitamin that contained large quantities of lead and mercury for four years. -twelve cases of lead poisoning among adults using ayurvedic reme- dies were reported to the centers for disease control and pre- vention in recent years.8 potentially toxic quantities of lead have been detected in 11 different dietary supplements.9 appropriate uses and contraindications of herbs. -herbal reme- dies alone may be appropriate for minor ailments a cup of chamomile tea to ease gastric discomfort or the gel of an aloe vera plant to soothe a sunburn, for example but not for major health problems such as cancer or aids. -effectiveness of herbs. -herbal remedies may claim to work wonders without having to prove effectiveness. -research studies often report conflicting findings, with some sug- gesting a benefit and others indicating no effectiveness.10 variability of herbs. -not all species are created equal. -the var- ious species of coneflower provide an example. -echinacea complementary and alternative medicine 657 table h18-2 selected herbs, their common use, and risks common name scientific source name claims and uses risksa aloe (gel) black cohosh aloe vera promote wound healing generally considered safe actaea racemos (formerly cimicifuga racemosa) ease menopause symptoms may cause clotting in blood vessels of the eye, change the curvature of the cornea chamomile (flowers) matricaria chamomilla relieve indigestion generally considered safe chaparral (leaves and twigs) larrea tridentata comfrey (leafy plant) echinacea (roots) symphytum officinale, s. asperum, s. x uplandicum enchinacea angustifolia, e. pallida, e. purpurea slow aging, cleanse blood, heal wounds, cure cancer, treat acne acute, toxic hepatitis; liver damage soothe nerves liver damage alleviate symptoms of colds, flus, and infections; promote wound healing; boost immunity generally considered safe; may cause headache, dizziness, nausea ephedra (stems) ephedra sinica promote weight loss feverfew (leaves) tanacetum parthenium prevent migraine headaches garlic (bulbs) allium sativum lower blood lipids and blood pressure rapid heart rate, tremors, seizures, insomnia, headaches, hypertension generally considered safe; may cause mouth irritation, swelling, ulcers, and gi distress generally considered safe; may cause garlic breath, body odor, gas, and gi distress; inhibits blood clotting ginger zingiber officinale prevent motion sickness, nausea generally considered safe ginkgo (tree leaves) ginkgo biloba improve memory, relieve vertigo generally considered safe; may cause headache, gi distress, dizziness; may inhibit blood clotting generally considered safe; may cause insomnia and high blood pressure ginseng (roots) panax ginseng (asian), p. quinquefolius (american) goldenseal (roots) hydrastis canadensis boost immunity, increase endurance relieve indigestion, treat urinary infections generally considered safe; not safe for people with hypertension or heart disease kava piper methysticum relieves anxiety, promotes relaxation liver failure saw palmetto (ripe fruits) serenoa repens relieve symptoms of enlarged prostate; diuretic; enhance sexual vigor generally considered safe; may cause nausea, vomiting, diarrhea st. john s wort (leaves and tops) valerian (roots) hypericum perforatum relieve depression and anxiety generally considered safe; may cause fatigue and gi distress valeriana officinalis calm nerves, improve sleep long term use associated with liver damage yohimbe (tree bark) pausinystalia yohimbe enhance male performance kidney failure, seizures aallergies are always a possible risk; see table h18-3 for drug interactions. -pregnant women should not use herbal supplements. -purpurea, for example, may help in the early treatment of colds, but echinacea augustifolia may not.11 similarly, not all parts of a plant provide the same compounds. -leaves, roots, and oils contain different compounds and extracts, and the temperatures used during manufacturing may affect their po- tency. -consumers are not always aware of such differences, and manufacturers do not always make such distinctions when preparing and labeling supplements. -accuracy of labels. -supplements may contain none of an herb or mixed species, and labels are often inaccurate. -more often than not, supplements do not contain the species or the quantities of active ingredients stated on their labels.12 in at least two cases, supplements did not even contain herbs, but prescription medicines instead.13 such discrepancies in the contents of supplements interfere with scientific research and make it difficult to interpret the findings. -consumers may want to shop for supplements bearing a logo from either u.s. pharmacopeia or consumer lab indicating that the contents have been analyzed and found to contain the ingredients and quantities listed on the label. -safe dosages of herbs. -herbs may contain active ingredi- ents compounds that affect the body. -each of these active ingredients has a different potency, time of onset, duration of activity, and consequent effects, making the plant itself too unpredictable to be useful. -foxglove leaves, for exam- ple, contain dozens of compounds that have an effect on the heart; digoxin, a drug derived from foxglove, offers a standard dosage that allows for a more predictable cardiac response. -even when herbs are manufactured into capsules or liquids, their concentrations of active ingredients differ dramatically from batch to batch and from the quantities stated on the labels.14 interactions of herbs with medicines and other herbs. -like drugs, herbs may interfere with, or potentiate, the effects of 658 highlight 18 other herbs and drugs (see table h18-3). -a person taking both cardiac medication and the herb foxglove may be headed for disaster from the combined effect on the heart. -similarly, taking st. john s wort with medicines used to treat heart disease, depression, seizures, and certain cancers might diminish or exaggerate the intended effects.15 be- cause ginkgo biloba impairs blood clotting, it can cause bleeding problems for people taking aspirin or other blood- thinning medicines regularly. -adverse reactions and toxicity levels of herbs. -herbs may pro- duce undesirable reactions. -the herb ephedra, commonly known as ma huang and used to promote weight loss, acts as a strong central nervous system stimulant, causing rapid heart rate, headaches, insomnia, tremors, seizures, and even death. -the herbal root kava, commonly used to treat anxiety and insomnia, can cause liver abnormalities and may have such a sedating effect as to impair driving. -chi- nese herbal treatments containing aristolochia fangchi are notorious for causing kidney damage and cancers. -table h18-2 (p. 659) includes risks associated with commonly used herbs. -to ensure the safety and standardization of herbal remedies, con- gress needs to establish regulations.16 because herbal medicines are sold as dietary supplements, their labels cannot claim to cure a disease, but they can make var- ious other claims. -not surprisingly, when a label claims that an herbal product may strengthen immunity, improve memory, sup- port eyesight, or maintain heart health, consumers believe that taking the product will provide those benefits. -beware. -manufac- turers need not prove effectiveness; they only need to state on the product label that this claim has not been evaluated by the table h18-3 herb and drug interactions fda. -consumers who decide to use herbs need to become in- formed of the possible risks. -internet precautions as highlight 1 pointed out, just because something appears on the internet, it ain t necessarily so. -keep in mind that the thou- sands of websites touting the benefits of herbal medicines and other dietary supplements are marketing their products. -most product advertisements claim to prevent or treat specific diseases, but few include the fda disclaimer statement.17 many of the websites promote products by quoting researchers or physicians. -such quotations lend an air of authority to advertisements, but be aware that these sources may not even exist and if they do, their comments may have been taken out of context. -when asked, they may not agree at all with the claims attributed to them by the manufacturer. -other deceits and dangers lurk in cyberspace as well. -potentially toxic substances, illegal and unavailable in many countries, are now easy to obtain via the internet. -electronic access to products such as absinthe and oil of wormwood could be deadly. -when the fda dis- covers websites selling unapproved drugs, such as laetrile, it can or- der the business to shut down. -but consumers need to remain vigilant because other similar businesses pop up quickly. -the consumer s perspective some health care professionals may dismiss alternative therapies as ineffective and perhaps even dangerous, but many consumers herb american ginseng american ginseng drug interaction estrogens, corticosteroids enhances hormonal response breast cancer therapeutic agent synergistically inhibits cancer cell growth american ginseng, karela blood glucose regulators echinacea (possible immunostimulant) cyclosporine and corticosteroids (immunosuppressants) affect blood glucose levels may reduce drug effectiveness evening primrose oil, borage anticonvulsants lower seizure threshold feverfew aspirin, ibuprofen,and other nonsteroidal anti-inflammatory drugs negates the effect of the herb in treating migraine headaches feverfew, garlic, ginkgo, ginger, and asian ginseng warfarin, coumarin (anticlotting drugs, blood thinners ) prolong bleeding time; increase likelihood of hemorrhage garlic kava, valerian kelp (iodine source) protease inhibitor (hiv drug) may reduce drug effectiveness anesthetics may enhance drug action synthroid or other thyroid hormone replacers interferes with drug action kyushin, licorice, plantain, uzara root, hawthorn, asian ginseng digoxin (cardiac antiarrhythmic drug derived from the herb foxglove) st. john s wort, saw palmetto, black tea iron st. john s wort protease inhibitors (hiv drugs), warfarin (anticlotting drug), digoxin (cardiac antiarrhytmic drug), oral contraceptives, tamoxifen (breast cancer drug) interfere with drug action and monitoring tannins in herbs inhibit iron absorption may enhance or reduce drug effectiveness valerian barbiturates causes excessive sedation complementary and alternative medicine 659 think otherwise. -in a survey of more than 2000 people, two-thirds had used at least one alternative therapy for a variety of medical complaints ranging from anxiety and headaches to cancer and tumors.18 interestingly, those who seek alternative therapies seem to do so not so much because they are dissatisfied with conven- tional medicine as because they find these alternatives more in line with their beliefs about health and life. -most often, people use alternative therapies in addition to, rather than in place of, conventional therapies. -few consult an al- ternative therapist without also seeing a physician. -in fact, most people seek alternative therapies for nonserious medical condi- tions or for health promotion. -they simply want to feel better and access is easy. -sometimes their symptoms are chronic and subjec- tive, such as pain and fatigue, and difficult to treat. -in these cases, the chances of finding relief are often as good with a placebo, standard medical intervention, or even nonintervention. -consumers spend billions of dollars on alternative health ser- vices and related products such as herbs, crystals, and aromas. -as highlight 1 pointed out, selecting a reliable practitioner depends on finding out about training, qualifications, and licenses. -(to review how a person can identify health fraud and quackery, turn to pp. -33 34. for a list of credible sources of nutrition informa- tion, see p. -33.) -in addition, consumers should inform their physicians about the use of any alternative therapies so that a comprehensive treat- ment plan can be developed and potential problems can be averted. -as mentioned, herb-drug interactions can create prob- lems, and one in six clients who takes prescription drugs also uses herbal products.19 when considering herbal products, remember to include supplements, teas, and garden plants.20 sometimes herbal products may need to be discontinued, especially before surgery when interactions with anesthesia or normal blood clot- ting can be life-threatening.21 alternative therapies come in a variety of shapes and sizes. -both their benefits and their risks may be small, none, or great. -wise consumers and health care professionals accept the beneficial, or even neutral, practices with an open mind and reject those prac- tices known to cause harm. -making healthful choices requires un- derstanding all the choices. -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 18, then to highlights nutrition on the net. -search for alternative medicine, herbs, holistic health, homeopathy, and preventive medicine at the u.s. government health information site: www.healthfinder.gov learn about complementary and alternative medicine from the national institutes of health s national center for complementary and alternative medicine: ww.nccam.nih.gov find out more about herbs from the american botanical council: www.herbalgram.org report adverse effects associated with herbal remedies to the fda medwatch: www.fda.gov/medwatch obtain information on herbal medications from herbmed or from the integrative medicine service at memorial sloan-kettering cancer center: www.herbmed.org or www.mskcc.org/aboutherbs get dietary supplement information from the national institutes of health s office of dietary supplements: dietary-supplements.info.nih.gov search cam on pubmed for a literature search of the com- review the backgrounds and practices of many popular plementary and alternative subset of pubmed: www.nlm.nih.gov/nccam/camonpubmed.html practitioners of alternative treatments: www.quackwatch.com references 1. p. m. barnes and e. powell-griner, comple- mentary and alternative medicine use among adults: united states, 2002, advance data from vital and health statistics 343 (2004): 1 19; g. m. kuo and coauthors, factors associated with herbal use among urban multiethnic primary care patients; a cross-sectional survey, bmc complementary and alternative medicine 4 (2004): 18 32. -2. r. touger-decker and c. a. thomson, complementary and alternative medicine: competencies for dietetics professionals, journal of the american dietetic association 103 (2003): 1465 1469; m. a. frenkel and j. m. borkan, an approach for integrating complementary-alternative medicine into primary care, family practice 20 (2003): 324 332. -3. committee on children with disabilities, american academy of pediatrics, counsel- ing families who choose complementary and alternative medicine for their child with chronic illness or disability, pediatrics 107 (2001): 598 601. -4. r. s. dipaola and r. a. morton, proven and unproven therapy for benign prostatic hyperplasia, new england journal of medicine 354 (2006): 632 634; m. d. kostka-rokosz and coauthors, selected herbal therapies, nutrition today 40 (2005): 17 28; s. lawvere and m. c. mahoney, st. john s wort, ameri- can family physician 72 (2005): 2249 2254; g. y. yeh and coauthors, systematic review of herbs and dietary supplements for glycemic control in diabetes, diabetes care 26 (2003): 1277 1294. -5. l. o. gostin, medical marijuana, american federalism, and the supreme court, journal of the american medical association 294 (2005): 842 844. -6. c. d. morris and s. carson, summary of evidence: routine vitamin supplementation to prevent cardiovascular disease, annals of internal medicine 139 (2003): 56 70; c. ritenbaugh, k. streit, and m. helfand, summary of evidence from randomized controlled trials: routine vitamin supple- mentation to prevent cancer, available from the agency for healthcare research and quality, www.preventiveservices.ahrq.gov. -7. e. ernst, the risk-benefit profile of com- monly used herbal therapies: ginkgo, st. john s wort, ginseng, echinacea, saw pal- metto, and kava, annals of internal medicine 660 highlight 18 136 (2002): 42 53; hepatic toxicity possibly associated with kava-containing products united states, germany, and switzerland, 1999 2002, morbidity and mortality weekly report 51 (2002): 1065 1067; s. foster and v. e. tyler, tyler s honest herbal: a sensible guide to the use of herbs and related remedies (new york: haworth press, 1999). -8. centers for disease control and prevention, lead poisoning associated with ayurvedi medications five states, 2000 2003, mor- bidity and mortality weekly report 53 (2004): 582 584. -9. s. p. dolan and coauthors, analysis of dietary supplements for arsenic, cadmium, mercury, and lead using inductively coupled plasma mass spectrometry, journal of agricultural and food chemistry 51 (2003): 1307 1312. -10. hypericum depression trial study group, effect of hypericum perforatum (st john s wort) in major depressive disorder: a ran- domized controlled trial, journal of the american medical association 287 (2002): 1807 1814; p. r. solomon and coauthors, ginkgo for memory enhancement: a ran- domized controlled trial, journal of the american medical association 288 (2002): 835 840. -11. k. linde and coauthors, echinacea for preventing and treating the common cold, cochrane database of systematic reviews 25 (2006): cd000530. -12. c. m. gilroy and coauthors, echinacea and truth in labeling, archives of internal medi- cine 163 (2003): 699 704; a. h. feifer, n. e. fleshner, and l. klotz, analytical accuracy and reliability of commonly used nutri- tional supplements in prostate disease, journal of urology 168 (2002): 150 154. -13. dietary-supplement recall, consumer reports on health, april 2002, p. 3. -14. m. r. karkey and co-authors, variability in commercial ginseng products: an analysis of 25 preparations, american journal of clinical nutrition 73 (2001): 1101 1106. -15. j. s. markowitz and coauthors, effect of st. john s wort on drug metabolism by induc- tion of cytochrome p450 3a4 enzyme, journal of the american medical association 290 (2003): 1500 1504. -16. c. d. deangelis and p. b. fontanarosa, drugs alias dietary supplements, journal of the american medical association 290 (2003): 1519 1520; d. m. marcus and a. p. groll- man, botanical medicines the need for new regulations, new england journal of medicine 347 (2002): 2073 2076. -17. c. a. morris and j. avron, internet market- ing of herbal products, journal of the ameri- can medical association 290 (2003): 1505 1509. -18. r. c. kessler and coauthors, long-term trends in the use of complementary and alternative medical therapies in the united states, annals of internal medicine 135 (2001): 262 268. -19. d. w. kaufman and coauthors, recent patterns of medication use in the ambula- tory adult population of the united states: the slone survey, journal of the american medical association 287 (2002): 337 344. -20. m. a. kuhn, herbal remedies: drug-herb interactions, critical care nurse 22 (2002): 22 28. -21. m. k. ang-lee, j. moss, and c. s. yuan, herbal medicines and perioperative care, journal of the american medical association 286 (2001): 208 216. this page intentionally left blank altrendo images/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow do you know what causes food poisoning and how to protect yourself against it? -were you alarmed to learn that french fries contain acrylamide or that fish contain mercury? -are you concerned about the pesticides that might linger on nutrition portfolio journal fruits and vegetables or the hormones and antibiotics that remain in beef and chicken? -do you wonder whether foods contain enough nutrients or too many additives? -making informed choices and practicing a few food safety tips will allow you to enjoy a variety of foods while limiting your risks of experiencing food-related illnesses. -consumer concerns about foods and water take a moment to consider the task of supplying food to 300 million peo- ple in the united states (and millions more in all corners of the world). -to feed this nation, farmers grow and harvest crops; dairy producers supply milk products; ranchers raise livestock; shippers deliver foods to manufac- turers by land, sea, and air; manufacturers prepare, process, preserve, and package products for refrigerated food cases and grocery-store shelves; and grocers store the food and supply it to consumers. -after much time, much labor, and extensive transport, an abundant supply of a large variety of safe foods finally reaches consumers at reasonable market prices. -the fda and other government and international agencies monitor this huge system using a network of people and sophisticated equipment. -(the glossary on p. 666 identifies the various food regulatory agencies by their abbreviations.) -these agencies focus on the potential hazard of c h a p t e r 19 chapter outline foodborne illnesses foodborne infections and food intoxications food safety in the marketplace food safety in the kitchen food safety while traveling advances in food safety nutritional adequacy of foods and diets obtaining nutrient infor- mation minimizing nutrient losses environmental contaminants harmfulness of environmental contami- nants guidelines for consumers natural toxicants in foods pesticides hazards and regulations of pesticides monitoring pesticides consumer concerns food additives regulations govern- ing additives intentional food additives indirect food additives consumer concerns about water sources of drinking water water sys- tems and regulations foods, which differs from the toxicity of a substance a distinction worth highlight 19 food biotechnology understanding. -anything can be toxic. -toxicity simply means that a sub- stance can cause harm if enough is consumed. -we consume many sub- stances that are toxic, without risk, because the amounts are so small. -the term hazard, on the other hand, is more relevant to our daily lives because it refers to the harm that is likely under real-life conditions. -consumers rely on these monitoring agencies to set safety standards and can learn to pro- tect themselves from food hazards by taking a few preventive measures. -after the events of september 11, 2001, the threat of deliberate contam- ination of the u.s. food supply became a pressing issue.1 to tighten security around the nation s food supply, the fda now requires all people who manufacture, produce, process, pack, transport, distribute, store, or import food to maintain records identifying the immediate previous source and subsequent recipient. -the agricultural and food biosecurity agency of the usda works to protect agriculture and other aspects of the food supply. -other agencies are also taking action, but details of the war against do- hazard: a source of danger; used to refer to circumstances in which harm is possible under normal conditions of use. -toxicity: the ability of a substance to harm living organisms. -all substances are toxic if high enough concentrations are used. -risk: a measure of the probability and severity of harm. -safety: the condition of being free from harm mestic bioterrorism are beyond the scope of this discussion. -or danger. -663 664 chapter 19 this chapter focuses on actions of individuals to promote food safety. -it addresses the following food safety concerns: s e g a m i y t t e g / c s i d o t o h p y r e g a m i l a t i g i d with the benefits of a safe and abundant food supply comes the responsibility to select, pre- pare, and store foods safely. -get medical help for these symptoms: bloody diarrhea diarrhea lasting more than 3 days difficulty breathing difficulty swallowing double vision fever lasting more than 24 hours headache, muscle stiffness, and fever numbness, muscle weakness, and tin- gling sensations in the skin rapid heart rate, fainting, and dizziness among foodborne infections, salmonella is the major cause of illness and listeria is the major cause of death. -foodborne illness: illness transmitted to human beings through food and water, caused by either an infectious agent (foodborne infection) or a poisonous substance (food intoxication); commonly known as food poisoning. -pathogen (path-oh-jen): a microorganism capable of producing disease. -foodborne illnesses nutritional adequacy of foods environmental contaminants naturally occurring toxicants pesticides food additives water safety the chapter begins with the fda s highest priority the serious and preva- lent threat of foodborne illnesses. -the highlight that follows looks at genet- ically engineered foods. -foodborne illnesses the fda lists foodborne illness as the leading food safety concern because episodes of food poisoning far outnumber episodes of any other kind of food con- tamination. -the cdc estimates that 76 million people experience foodborne illness each year in the united states.2 for some 5000 people each year, the symptoms can be so severe as to cause death. -most vulnerable are pregnant women; very young, very old, sick, or malnourished people; and those with a weakened immune system (as in aids). -by taking the proper precautions, people can minimize their chances of contracting foodborne illnesses. -foodborne infections and food intoxications foodborne illness can be caused by either an infection or an intoxication. -table 19-1 summarizes the most common or severe foodborne illnesses, along with their food sources, general symptoms, and prevention methods. -foodborne infections foodborne infections are caused by eating foods contam- inated by infectious microbes. -the most common foodborne pathogen is salmo- nella, which enters the gi tract in contaminated foods such as undercooked poultry and unpasteurized milk. -symptoms generally include abdominal cramps, fever, vomiting, and diarrhea. -g lossary of agencies that monitor the food supply cdc (centers for disease control): a branch of the department of health and human services that is responsible for, among other things, monitoring foodborne diseases. -www.cdc.gov epa (environmental protection agency): a federal agency that is responsible for, among other things, regulating pesticides and establishing water quality standards. -www.epa.gov fao (food and agriculture organization): an international agency (part of the united nations) that has adopted standards to regulate pesticide use among other responsibilities. -www.fao.org usda (u.s. department of agriculture): the federal agency responsible for enforcing standards for the wholesomeness and quality of meat, poultry, and eggs produced in the united states; conducting nutrition research; and educating the public about nutrition. -www.usda.gov who (world health organization): an international agency concerned with promoting health and eradicating disease. -www.who.ch reminder: fda (food and drug administration) is a part of the department of health and human services public health service that is responsible for ensuring the safety and wholesomeness of all dietary supplements and foods processed and sold in interstate commerce except meat, poultry, and eggs (which are under the jurisdiction of the usda); inspecting food plants and imported foods; and setting standards for food composition and product labeling. -www.fda.gov consumer concerns about foods and water 665 foodborne illnesses table 19-1 disease and organism that causes it foodborne infections campylobacteriosis (kam-pee-loh-bak-ter-ee-oh-sis) campylobacter bacterium cryptosporidiosis (krip-toe-spo-rid-ee-oh-sis) crytosporidium parvum parasite cyclosporiasis (sigh-clo-spore-eye-uh-sis) cyclospora cayetanensis parasite e. coli infection escherichia coli b bacterium gastroenteritisc norwalk virus most frequent food sources onset and general symptoms prevention methodsa raw and undercooked poultry, unpasturized milk, contaminated water commonly contaminated swimming or drinking water, even from treated sources. -highly chlorine-resistant. -contaminated raw produce and unpasteurized juices and ciders contaminated water; contaminated fresh produce undercooked ground beef, unpasteurized milk and juices, raw fruits and vegetables, contaminated water, and person-to-person contact onset: 2 to 5 days. -diarrhea, vomiting, abdominal cramps, fever; sometimes bloody stools; lasts 2 to 10 days. -cook foods thoroughly; use pasteurized milk; use sanitary food-handling methods. -onset: 2 to 10 days. -diarrhea, stomach cramps, upset stomach, slight fever; symptoms may come and go for weeks or months. -wash all raw vegetables and fruits before peeling. -use pasteurized milk and juice. -do not swallow drops of water while using pools, hot tubs, ponds, lakes, rivers, or streams for recreation. -onset: 1 to 14 days. -watery diarrhea, loss of appetite, weight loss, stomach cramps, nausea, vomiting, fatigue; symptoms may come and go for weeks or months. -use treated, boiled, or bottled water; cook foods thoroughly; peel fruits. -onset: 1 to 8 days. -severe bloody diarrhea, abdominal cramps, vomiting; lasts 5 to 10 days. -cook ground beef thoroughly; use pasteurized milk; use sanitary food-handling methods; use treated, boiled, or bottled water. -person-to-person contact; raw foods, salads, sandwiches onset: 1 to 2 days. -vomiting; lasts 1 to 2 days. -use sanitary food-handling methods. -giardiasis (jye-are-dye-ah-sis) giardia intestinalis parasite contaminated water; uncooked foods onset: 7 to 14 days. -diarrhea (but occasionally constipation), abdominal pain, gas. -use sanitary food-handling methods; avoid raw fruits and vegetables where parasites are endemic; dispose of sewage properly. -hepatitis (hep-ah-tie-tis) hepatitis a virus undercooked or raw shellfish listeriosis (lis-ter-ee-oh-sis) listeria monocytogenes bacterium unpasteurized milk; fresh soft cheeses; luncheon meats, hot dogs perfringens (per-fringe-enz) food poisoning clostridium perfringens bacterium meats and meat products stored at between 120 and 130 f salmonellosis (sal-moh-neh-loh-sis) salmonella bacteria ((cid:2)2300 types) shigellosis (shi-gel-loh-sis) shigella bacteria ((cid:2)30 types) vibrio (vib-ree-oh) bacteria vibrio vulnificus d bacterium raw or undercooked eggs, meats, poultry, raw milk and other dairy products, shrimp, frog legs, yeast, coconut, pasta, and chocolate person-to-person contact, raw foods, salads, sandwiches, and contaminated water raw or undercooked seafood and contaminated water. -onset: 15 to 50 days (28 days average). -diarrhea, dark urine, fever, headache, nausea, abdominal pain, jaundice (yellowed skin and eyes from buildup of wastes); lasts 2 to 12 weeks. -onset: 1 to 21 days. -fever, muscle aches; nausea, vomiting, blood poisoning, complications in pregnancy, and meningitis (stiff neck, severe headache, and fever). -onset: 8 to 16 hr. -abdominal pain, diarrhea, nausea; lasts 1 to 2 days. -cook foods thoroughly. -use sanitary food-handling methods; cook foods thoroughly; use pasteurized milk. -use sanitary food-handling methods; cook foods thoroughly; refrigerate foods promptly and properly. -onset: 1 to 3 days. -fever, vomiting abdominal cramps, diarrhea; lasts 4 to 7 days; can be fatal. -use sanitary food-handling methods; use pasteurized milk; cook foods thoroughly; refrigerate foods promptly and properly. -onset: 1 to 2 days. -bloody diarrhea, cramps, fever; lasts 4 to 7 days. -use sanitary food-handling methods; cook foods thoroughly; proper refrigeration. -onset: 1 to 7 days. -diarrhea, abdominal cramps, nausea, vomiting; lasts 2 to 5 days; can be fatal. -use sanitary food-handling methods; cook foods thoroughly. -yersiniosis (yer-sin-ee-oh-sis) yersinia enterocolitica bacterium raw and undercooked pork, unpasteurized milk onset: 1 to 2 days. -diarrhea, vomiting, fever, abdominal pain; lasts 1 to 3 weeks. -cook foods throughly; use pasteurized milk; use treated, boiled, or bottled water. -food intoxications botulism (bot-chew-lizm) botulinum toxin [produced by clostridium botulinum bacterium, which grows without oxygen, in low-acid foods, and at temperatures between 40 and 120 f; the botulinum (bot-chew-line-um) toxin responsible for botulism is called botulin (bot-chew-lin)] staphylococcal (staf-il-oh-kok-al) food poisoning staphylococcal toxin (produced by staphylococcus aureus bacterium) anaerobic environment of low acidity (canned corn, peppers, green beans, soups, beets, asparagus, mushrooms, ripe olives, spinach, tuna, chicken, chicken liver, liver p te, luncheon meats, ham, sausage, stuffed eggplant, lobster, and smoked and salted fish) toxin produced in improperly refrigerated meats; egg, tuna, potato, and macaroni salads; cream-filled pastries onset: 4 to 36 hr. -nervous system symptoms, including double vision, inability to swallow, speech diffi- culty, and progressive paralysis of the respiratory system; often fatal; leaves prolonged symptoms in survivors. -use proper canning methods for low-acid foods; refrigerate homemade garlic and herb oils; avoid commercially prepared foods with leaky seals or with bent, bulging, or broken cans. -onset: 1 to 6 hr. -diarrhea, nausea, vomiting, abdominal cramps, fever; lasts 1 to 2 days. -use sanitary food-handling methods; cook food thoroughly; refrigerate foods promptly and properly; use proper home-canning methods. -note: travelers diarrhea is most commonly caused by e. coli, campylobacter jejuni, shigella, and salmonella. -athe how to on pp. -672 673 provides more details on the proper handling, cooking, and refrigeration of foods. -bthe most serious strain is e. coli stec o157. -cgastroenteritis refers to an inflammation of the stomach and intestines but is the most common name used for illnesses caused by norwalk viruses. -dmost cases of vibrio vulnificus occur in persons with underlying illness, particularly those with liver disorders, diabetes, cancer, and aids, and those who require long-term steroid use. -the fatality rate is 50 percent for this population. -666 chapter 19 to prevent food intoxication from homemade flavored oils, wash and dry the herbs before adding them to the oil and keep the oil refrigerated. -pasteurization: heat processing of food that inactivates some, but not all, microorganisms in the food; not a sterilization process. -bacteria that cause spoilage are still present. -hazard analysis critical control points (haccp): a systematic plan to identify and correct potential microbial hazards in the manufacturing, distribution, and commercial use of food products; commonly referred to as hass-ip. -. -c n i , s o i d u t s a r a l o p food intoxications food intoxications are caused by eating foods containing natural toxins or, more likely, microbes that produce toxins. -the most common food toxin is produced by staphylococcus aureus; it affects more than one million people each year. -less common, but more infamous, is clostridium botulinum, an organism that produces a deadly toxin in anaerobic conditions such as improperly canned (especially home-canned) foods and homemade garlic or herb-flavored oils stored at room temperature. -because the toxin paralyzes muscles, a person with botulism has difficulty seeing, speaking, swallowing, and breathing.3 because death can occur within 24 hours of onset, botulism demands immediate medical attention. -even then, survivors may suffer the effects for months or years. -food safety in the marketplace transmission of foodborne illness has changed as our food supply and lifestyles have changed.4 in the past, foodborne illness was caused by one person s error in a small setting, such as improperly refrigerated egg salad at a family picnic, and af- fected only a few victims. -today, we eat more foods that have been prepared and packaged by others. -consequently, when a food manufacturer or restaurant chef makes an error, foodborne illness can become epidemic. -an estimated 80 percent of reported foodborne illnesses are caused by errors in a commercial setting, such as the improper pasteurization of milk at a large dairy. -in the mid-1990s, when a fast-food restaurant served undercooked burgers tainted with an infectious strain of escherichia coli, hundreds of patrons became ill, and at least three people died. -in the early 2000s, a national food company had to recall more than 4 million pounds of poultry products after listeria poisoning killed 7 people and made more than 50 others sick. -in the 2006 e. coli outbreak due to contaminated fresh spinach, nearly 200 people became sick, and 2 elderly women and a 2-year-old boy died before consumers got the fda message to not eat fresh spinach. -these incidents and others have focused the national spotlight on two im- portant safety issues: disease-causing organisms are commonly found in raw foods, and thorough cooking kills most of these foodborne pathogens. -this heightened awareness sparked a much needed overhaul of national food safety programs. -industry controls to make our food supply safe for consumers, the usda, the fda, and the food-processing industries have developed and implemented programs to control foodborne illness. -* the hazard analysis critical control points (haccp) system requires food manufacturers to identify points of contamination and implement controls to prevent foodborne disease. -for example, after tracing two large outbreaks of salmonellosis to imported cantaloupe, producers began using chlorinated water to wash the melons and to make ice for packing and shipping. -safety procedures such as this prevent hundreds of thousands of foodborne illnesses each year and are responsible for the decline in infections over the past decade.5 this example raises another issue regarding the safety of imported foods. -fda inspectors cannot keep pace with the increasing numbers of imported foods; they inspect fewer than 2 percent of the almost 3 million shipments of fruits, vegeta- bles, and seafood coming into more than 300 ports in the united states each year. -the fda is working with other countries to adopt the safe food-handling practices used in the united states. -consumer awareness canned and packaged foods sold in grocery stores are eas- ily controlled, but rare accidents do happen. -batch numbering makes it possible to recall contaminated foods through public announcements via newspapers, tel- evision, and radio. -in the grocery store, consumers can buy items before the sell by date and inspect the safety seals and wrappers of packages. -a broken seal, bulging can lid, or mangled package fails to protect the consumer against mi- crobes, insects, spoilage, or even vandalism. -* in addition to haccp, these programs include the emerging infections program (eip), the foodborne diseases active surveillance network (foodnet), and the food safety inspection service (fsis). -figure 19-1 food safety from farms to consumers consumer concerns about foods and water 667 farms workers must use safe methods of growing, harvesting, sorting, packing, and storing food to minimize contamination hazards. -processing processors must follow fda guidelines concerning contamination, cleanliness, and education and training of workers and must monitor for safety at critical control points (use haccp, see text). -transportation containers and vehicles transporting food must be clean. -cold food must be kept cold at all times. -retail grocery store and restaurant employees must follow the fda s food code on how to prevent foodborne illnesses. -establishments must pass local health inspections and train staff in sanitation. -consumers consumers must learn and use sound principles of food safety as taught in this chapter. -be mindful that foodborne illness is a real possibility and take steps to prevent it. -state and local health regulations provide guidelines on the cleanliness of facil- ities and the safe preparation of foods for restaurants, cafeterias, and fast-food es- tablishments. -even so, consumers can also take these actions to help prevent foodborne illnesses when dining out: figure 19-2 fight bac! -four ways to keep food safe. -the fight bac! -website is at www.fightbac.org. -wash hands with hot, soapy water before meals. -expect clean tabletops, dinnerware, utensils, and food preparation areas. -expect cooked foods to be served piping hot and salads to be fresh and cold. -refrigerate doggy bags within two hours. -improper handling of foods can occur anywhere along the line from commercial manufacturers to large supermarkets to small restaurants to private homes. -main- taining a safe food supply requires everyone s efforts (see figure 19-1). -food safety in the kitchen whether microbes multiply and cause illness depends, in part, on a few key food- handling behaviors in the kitchen whether the kitchen is in your home, a school cafeteria, a gourmet restaurant, or a canning manufacturer.6 figure 19-2 summa- rizes the four simple things that can help most to prevent foodborne illness: keep a clean, safe kitchen. -wash countertops, cutting boards, hands, sponges, and utensils in hot, soapy water before and after each step of food preparation. -dietary guidelines for americans 2005 to avoid microbial foodborne illness, clean hands, food contact surfaces, and fruits and vegetables. -avoid cross-contamination. -keep raw eggs, meat, poultry, and seafood separate from other foods. -wash all utensils and surfaces (such as cutting boards or plat- ters) that have been in contact with these foods with hot, soapy water before using them again. -bacteria inevitably left on the surfaces from the raw meat can recontaminate the cooked meat or other foods a problem known as cross-contamination. -washing raw eggs, meat, and poultry is not recom- mended because the extra handling increases the risk of cross-contamination. -cross-contamination: the contamination of food by bacteria that occurs when the food comes into contact with surfaces previously touched by raw meat, poultry, or seafood. -668 chapter 19 wash your hands with warm water and soap for at least 20 seconds before preparing or eat- ing food to reduce the chance of microbial contamination. -dietary guidelines for americans 2005 to avoid microbial foodborne illness, separate raw, cooked, and ready-to- eat foods while shopping, preparing, or storing foods. -keep hot foods hot. -cook foods long enough to reach internal temperatures that will kill microbes, and maintain adequate temperatures to prevent bac- terial growth until the foods are served. -dietary guidelines for americans 2005 to avoid microbial foodborne illness, cook foods to a safe temperature to kill microorganisms. -s e g a m i y t t e g / c s i d o t o h p keep cold foods cold. -go directly home upon leaving the grocery store and im- mediately place foods in the refrigerator or freezer. -after a meal, refrigerate any leftovers immediately. -dietary guidelines for americans 2005 to avoid microbial foodborne illness, chill (refrigerate) perishable food promptly and defrost foods properly. -unfortunately, consumers commonly fail to follow these simple food-handling rec- ommendations.7 see the how to on p. 670 671 for additional food safety tips. -safe handling of meats and poultry figure 19-3 presents label instructions for the safe handling of meat and poultry and two types of usda seals. -meats and poul- try contain bacteria and provide a moist, nutrient-rich environment that favors mi- crobial growth. -ground meat is especially susceptible because it receives more handling than other kinds of meat and has more surface exposed to bacterial con- tamination. -consumers cannot detect the harmful bacteria in or on meat. -for safety s sake, cook meat thoroughly, using a thermometer to test the internal tem- perature (see figure 19-4). -dietary guidelines for americans 2005 to avoid microbial foodborne illness, meat and poultry should not be washed or rinsed. -mad cow disease reports on mad cow disease from dozens of countries, includ- ing canada and the united states, have sparked consumer concerns.8 mad cow dis- ease is a slowly progressive, fatal condition that affects the central nervous system of cattle. -* a similar disease develops in people who have eaten contaminated beef from infected cows (milk products appear to be safe). -** approximately 150 cases have been reported worldwide, primarily in the united kingdom. -the usda has taken numerous steps to prevent the transmission of mad cow disease in cattle, and if these measures are followed, then risks from u.s. cattle are low.9 because the infec- tious agents occur in the intestines, central nervous system, and other organs, but not in muscle meat, concerned consumers may want to select whole cuts of meat in- stead of ground beef or sausage. -a few recent reports of hunters developing fatal neurological disorders have raised concerns about a similar disease in wild game. -hunters and consumers who regularly eat elk, deer, or antelope should check the ad- visories of their state department of agriculture. -*mad cow disease is technically known as bovine spongiform encephalopathy (bse). -** the human form of bse is called the variant creutzfeldt-jakob disease (vcjd). -consumer concerns about foods and water 669 s e g a m i y t t e g / l l e n n o c o c i r e cook hamburgers to 160 f; color alone cannot determine doneness. -some burgers will turn brown before reaching 160 f, whereas others may retain some pink color, even when cooked to 175 f. figure 19-3 meat and poultry safety, grading, and inspection seals inspection is mandatory; grading is voluntary. -neither guarantees that the prod- uct will not cause foodborne illnesses, but consumers can help to prevent food- borne illnesses by following the safe handling instructions. -u.s.d.a. -select the voluntary graded by usda seal indicates that the product has been graded for tenderness, juiciness, and flavor. -beef is graded prime (abundant marbling of the meat muscle), choice (less marbling), and select (lean). -similarly, poultry is graded a, b, and c. safe handling instructions this product was prepared from inspected and passed meat and/or poultry. -some food products may contain bacteria that can cause improperly. -illness instructions. -for your protection, follow these safe handling is mishandled or cooked if the product the mandatory inspected and passed by the usda seal ensures that meat and poultry products are safe, wholesome, and correctly labeled. -inspection does not guarantee that the meat is free of potentially harmful bacteria. -keep refrigerated or frozen. -thaw in refrigerator or microwave. -keep raw meat and poultry separate from other foods. -wash working surfaces (including cutting boards), utensils, and hands after touching raw meat or poultry. -cook thoroughly. -c f keep hot foods hot. -refrigerate leftovers immediately or discard. -the usda requires that safe handling instructions appear on all packages of meat and poultry. -avian influenza avian influenza (bird flu) is a very contagious and life- threatening viral infection that naturally occurs among birds, including chickens, ducks, and turkeys. -the risk of bird flu in human beings is relatively low, and most cases have resulted from direct contact with infected birds or their contaminated en- vironment. -because the virus can change easily, scientists are concerned that it could infect people and spread rapidly from person to person, creating a pandemic. -importantly, bird flu is not transmitted by eating poultry. -figure 19-4 recommended safe temperatures (fahrenheit) bacteria multiply rapidly at temperatures between 40 and 140 f. cook foods to the temperatures shown on this thermometer and hold them at 140 f or higher. -170 165 160 145 140 40 0 well-done meats stuffing, poultry, reheat leftovers medium-done meats, raw eggs, egg dishes, pork, ground meats medium-rare beef steaks, roasts, veal, lamb hold hot foods danger zone: do not keep foods between 40 f and 140 f for more than 2 hours or for more than 1 hour when the air temperature is greater than 90 f. refrigerator temperatures freezer temperatures 670 chapter 19 how to prevent foodborne illness most foodborne illnesses can be prevented by following four simple rules: keep a clean kitchen, avoid cross-contamination, keep hot foods hot, and keep cold foods cold. -keep a clean kitchen wash fruits and vegetables in a clean sink with a scrub brush and warm water; store washed and unwashed produce separately. -use hot, soapy water to wash hands, uten- sils, dishes, nonporous cutting boards, and countertops before handling food and between tasks when working with different foods. -use a bleach solution on cutting boards (one capful per gallon of water). -cover cuts with clean bandages before food preparation; dirty bandages carry harmful microorganisms. -mix foods with utensils, not hands; keep hands and utensils away from mouth, nose, and hair. -anyone may be a carrier of bacteria and should avoid coughing or sneezing over food. -a person with a skin infection or infectious disease should not prepare food. -wash or replace sponges and towels regularly. -clean up food spills and crumb-filled crevices. -avoid cross-contamination wash all surfaces that have been in contact with raw meats, poultry, eggs, fish, and shellfish before reusing. -serve cooked foods on a clean plate. -sepa- rate raw foods from those that have been cooked. -don t use marinade that was in contact with raw meat for basting or sauces. -for at least 31 2 minutes; scrambled until set, not runny; fried for at least 3 minutes on one side and 1 minute on the other). -cook seafood thoroughly. -if you have safety questions about seafood call the fda hotline: (800) fda-4010. -when serving foods, maintain tempera- tures at 140 f or higher. -heat leftovers thoroughly to at least 165 f. keep hot foods hot when cooking meats or poultry, use a thermometer to test the internal tempera- ture. -insert the thermometer between the thigh and the body of a turkey or into the thickest part of other meats, making sure the tip of the thermometer is not in con- tact with bone or the pan. -cook to the temperature indicated for that particular meat (see figure 19-4 on p. 669); cook hamburgers to at least medium well-done. -if you have safety questions, call the usda meat and poultry hotline: (800) 535-4555. keep cold foods cold when running errands, stop at the grocery store last. -when you get home, refrigerate the perishable groceries (such as meats and dairy products) immediately. -do not leave perishables in the car any longer than it takes for ice cream to melt. -put packages of raw meat, fish, or poultry on a plate before refrigerating to prevent juices from dripping on food stored below. -buy only foods that are solidly frozen in cook stuffing separately, or stuff poultry store freezers. -just prior to cooking. -do not cook large cuts of meat or turkey in a microwave oven; it leaves some parts undercooked while overcooking others. -keep cold foods at 40 f or less; keep frozen foods at 0 f or less (keep a thermometer in the refrigerator). -marinate meats in the refrigerator, not on cook eggs before eating them (soft-boiled the counter. -s e g a m i y t t e g / d e r c s i d o t o h p / y e s a h c d i v a d safe handling of seafood most seafood available in the united states and canada is safe, but eating it undercooked or raw can cause severe illnesses hepatitis, worms, parasites, viral intestinal disorders, and other diseases. -* rumor has it that freezing fish will make it safe to eat raw, but this is only partly true. -com- mercial freezing kills mature parasitic worms, but only cooking can kill all worm eggs and other microorganisms that can cause illness. -for safety s sake, all seafood should be cooked until it is opaque. -even sushi can be safe to eat when chefs com- bine cooked seafood and other ingredients into these delicacies. -eating raw oysters can be dangerous for anyone, but people with liver disease and weakened immune systems are most vulnerable. -at least ten species of bacte- ria found in raw oysters can cause serious illness and even death. -** raw oysters may also carry the hepatitis a virus, which can cause liver disease. -some hot sauces can kill many of these bacteria, but not the virus; alcohol may also protect some people against some oyster-borne illnesses, but not enough to guarantee protection (or to recommend drinking alcohol). -pasteurization of raw oysters holding them at a specified temperature for a specified time holds promise for killing bacteria without cooking the oyster or altering its texture or flavor. -as population density increases along the shores of seafood-harvesting waters, pollution inevitably invades the sea life there. -preventing seafood-borne illness is in large part a task of controlling water pollution. -to help ensure a safe seafood mar- ket, the fda requires processors to adopt food safety practices based on the haccp system mentioned earlier. -* diseases caused by toxins from the sea include ciguatera poisoning, scombroid poisoning, and paralytic and neurotoxic shellfish poisoning. -** raw oysters can carry the bacterium vibrio vulnificus; see table 19-1 for details. -eating raw seafood is a risky proposition. -sushi: vinegar-flavored rice and seafood, typically wrapped in seaweed and stuffed with colorful vegetables. -some sushi is stuffed with raw fish; other varieties contain cooked seafood. -consumer concerns about foods and water 671 how to prevent foodborne illness, continued refrigerate leftovers promptly; use shallow containers to cool foods faster; use left- overs within 3 to 4 days. -discard foods that are discolored, moldy, or decayed or that have been contami- nated by insects or rodents. -thaw meats or poultry in the refrigerator, not at room temperature. -if you must hasten thawing, use cool water (changed every 30 minutes) or a microwave oven. -freeze meat, fish, or poultry immediately if not planning to use within a few days. -in general do not reuse disposable containers; use nondisposable containers or recycle instead. -do not taste food that is suspect. -if in doubt, throw it out. -throw out foods with danger-signaling odors. -be aware, though, that most food- poisoning bacteria are odorless, colorless, and tasteless. -do not buy or use items that have broken seals or mangled packaging; such contain- ers cannot protect against microbes, in- sects, spoilage, or even vandalism. -check safety seals, buttons, and expiration dates. -follow label instructions for storing and preparing packaged and frozen foods; throw out foods that have been thawed or refrozen. -for specific food items canned goods. -carefully discard food from cans that leak or bulge so that other people and animals will not accidentally ingest it; before canning, seek professional advice from the usda extension service (check your phone book under u.s. government listings, or ask directory assistance). -milk and cheeses. -use only pasteurized milk and milk products. -aged cheeses, such as cheddar and swiss, do well for an hour or two without refrigeration, but they should be refrigerated or stored in an ice chest for longer periods. -eggs. -use clean eggs with intact shells. -do not eat eggs, even pasteurized eggs, raw; raw eggs are commonly found in caesar salad dressing, eggnog, cookie dough, hollandaise sauce, and key lime pie. -cook eggs until whites are firmly set and yolks begin to thicken. -honey. -honey may contain dormant bacte- rial spores, which can awaken in the hu- man body to produce botulism. -in adults, this poses little hazard, but infants under one year of age should never be fed honey. -honey can accumulate enough toxin to kill an infant; it has been implicated in several cases of sudden infant death. -(honey can also be contaminated with environmental pollutants picked up by the bees.) -mayonnaise. -commercial mayonnaise may actually help a food to resist spoilage because of the acid content. -still, keep it cold after opening. -mixed salads. -mixed salads of chopped ingredients spoil easily because they have extensive surface area for bacteria to in- vade, and they have been in contact with cutting boards, hands, and kitchen utensils that easily transmit bacteria to food (regard- less of their mayonnaise content). -chill them well before, during, and after serving. -picnic foods. -choose foods that last with- out refrigeration such as fresh fruits and vegetables, breads and crackers, and canned spreads and cheeses that can be opened and used immediately. -pack foods cold, layer ice between foods, and keep foods out of water. -seafood. -buy only fresh seafood that has been properly refrigerated or iced. -cooked seafood should be stored separately from raw seafood to avoid cross-contamination. -chemical pollution and microbial contamination lurk not only in the water, but also in the boats and warehouses where seafood is cleaned, prepared, and refriger- ated. -because seafood is one of the most perishable foods, time and temperature are critical to its freshness, flavor, and safety. -to keep seafood as fresh as possible, people in the industry must keep it cold, keep it clean, and keep it moving. -wise consumers eat it cooked. -other precautions and procedures fresh food generally smells fresh. -not all types of food poisoning are detectable by odor, but some bacterial wastes produce off odors. -if an abnormal odor exists, the food is spoiled. -throw it out or, if it was recently purchased, return it to the grocery store. -do not taste it. -table 19-2 lists safe refrigerator storage times for selected foods. -local health departments and the usda extension service can provide additional information about food safety. -if precautions fail and a mild foodborne illness devel- ops, drink clear liquids to replace fluids lost through vomiting and diarrhea. -if serious foodborne illness is suspected, first call a physician. -then wrap the remainder of the suspected food and label the container so that the food cannot be mistakenly eaten, place it in the refrigerator, and hold it for possible inspection by health authorities. -dietary guidelines for americans 2005 to avoid microbial foodborne illness, avoid raw (unpasteurized) milk or any products made from unpasteurized milk, raw or partially cooked eggs or foods containing raw eggs, raw or undercooked meat and poultry, un- pasteurized juices, and raw sprouts. -table 19-2 storage times ((cid:3)40 f) safe refrigerator 1 to 2 days raw ground meats, breakfast or other raw sausages, raw fish or poultry; gravies 3 to 5 days raw steaks, roasts, or chops; cooked meats, poul- try, vegetables, and mixed dishes; lunch meats (packages opened); mayonnaise salads (chicken, egg, pasta, tuna) 1 week hard-cooked eggs, bacon or hot dogs (opened packages); smoked sausages or seafood 2 to 4 weeks raw eggs (in shells); lunch meats, bacon, or hot dogs (packages unopened); dry sausages (pepper- oni, hard salami); most aged and processed cheeses (swiss, brick) 2 months mayonnaise (opened jar); most dry cheese (parmesan, romano) 672 chapter 19 during the last century, pasteurization of milk helped to control typhoid fever, tuber- culosis, scarlet fever, diphtheria, and other infectious diseases. -foods approved for irradiation: eggs raw beef, lamb, poultry, pork spices, tea wheat vegetables (potatoes, tomatoes, onions) fresh fruit (strawberries, citrus, papaya) travelers diarrhea: nausea, vomiting, and diarrhea caused by consuming food or water contaminated by any of several organisms, most commonly, e. coli, shigella, campylobacter jejuni, and salmonella. -irradiation: sterilizing a food by exposure to energy waves, similar to ultraviolet light and microwaves. -ultrahigh temperature (uht) treatment: sterilizing a food by brief exposure to temperatures above those normally used. -food safety while traveling people who travel to other countries have a 50 50 chance of contracting a food- borne illness, commonly described as travelers diarrhea.10 like many other foodborne illnesses, travelers diarrhea is a sometimes serious, always annoying bacterial infection of the digestive tract. -the risk is high because, for one thing, some countries cleanliness standards for food and water are lower than those in the united states and canada. -for another, every region s microbes are different, and although people are immune to the microbes in their own neighborhoods, they have had no chance to develop immunity to the pathogens in places they are visit- ing for the first time. -the how to on the next page offers tips for food safety while traveling. -advances in food safety advances in technology have dramatically improved the quality and safety of foods available on the market. -from pasteurization in the early 1900s to irradiation in the early 2000s, these advances offer numerous benefits, but they also raise con- sumer concerns.11 irradiation the use of low-dose irradiation protects consumers from foodborne illnesses by:12 controlling mold in grains sterilizing spices and teas for storage at room temperature controlling insects and extending shelf life in fresh fruits and vegetables (in- hibits the growth of sprouts on potatoes and onions and delays ripening in some fruits such as strawberries and mangoes) destroying harmful bacteria in fresh and frozen beef, poultry, lamb, and pork some foods are not candidates for the treatment. -for example, when irradiated, high-fat meats develop off-odors, egg whites turn milky, grapefruits become mushy, and milk products change flavor. -(incidentally, the milk in those boxes kept at room temperature on grocery-store shelves is not irradiated; it is sterilized with an ultra- high temperature treatment.) -the use of food irradiation has been extensively evaluated over the past 50 years; approved for use in more than 40 countries; and supported by numerous health agencies, including the fao, who, and the american medical associa- tion. -irradiation does not make foods radioactive, nor does it noticeably change the taste, texture, or appearance of approved foods. -vitamin loss is minimal and comparable to amounts lost in other food-processing methods such as canning. -be- cause irradiation kills bacteria without the use of heat, it is sometimes called cold pasteurization. -consumer concerns about irradiation many consumers associate the term radiation with cancer, birth defects, and mutations, and consequently have strong negative emotions about using irradiation on foods. -some may mistakenly fear that irradiated food has been contaminated by radioactive particles, such as occurs in the aftermath of a nuclear accident. -some balk at the idea of irradiating, and thus sterilizing, contaminated foods and prefer instead the elimination of unsanitary slaughtering and food preparation conditions. -food producers, on the other hand, are eager to use irradiation, but they hesitate to do so until consumers are ready to accept it and willing to pay for it. -once consumers understand the benefits of irradi- ation, about half are willing to use irradiated foods, but only a fourth are willing to pay more.13 regulation of irradiation the fda has established regulations governing the specific uses of irradiation and allowed doses. -each food that has been treated with consumer concerns about foods and water 673 how to achieve food safety while traveling foodborne illnesses contracted while travel- ing are colloquially known as travelers diarrhea. -a bout of this ailment can ruin the most enthusiastic tourist s trip. -to avoid foodborne illness, follow the food safety tips outlined on pp. -670 671. in addition, while traveling: wash your hands often with soap and hot water, especially before handling food or eating. -use antiseptic gel or hand wipes. -eat only well-cooked and hot or canned foods. -eat raw fruits or vegetables only if you have washed them in purified water and peeled them yourself. -skip salads and raw fish and shellfish. -be aware that water, and ice made from it, may be unsafe. -use safe, bottled water for drinking, making ice cubes, and brushing teeth. -alternatively, take along disinfecting tablets or a device to boil water. -do not use ice unless it was made from purified or bottled water. -drink no beverages made with tap water. -drink only treated, boiled, canned, or bot- tled beverages, and drink them without ice, even if they are not chilled to your liking. -refuse dairy products unless they have been properly pasteurized and refrigerated. -do not buy food and drinks from street vendors. -before you leave on the trip, ask your physician to recommend an antimotility agent and an antibiotic to take with you in case your efforts to avoid illness fail. -to sum up these recommendations, boil it, cook it, peel it, or forget it. -chances are excellent that if you follow these rules, you will remain well. -irradiation must say so on its label. -labels can be misleading, however. -products that use irradiated foods as ingredients are not required to say so on the label. -fur- thermore, consumers may interpret the absence of the irradiation symbol to mean that the food was produced without any kind of treatment. -this is not true; it is just that the fda does not require label statements for other treatments used for the same purpose, such as postharvest fumigation with pesticides. -if all treatment meth- ods were declared, consumers could make fully informed choices. -this international symbol, called the radura, indentifies retail foods that have been irradiated. -the words treated by irra- diation or treated with irradiation must accompany the symbol. -the irradiation label is not required on commercially pre- pared foods that contain irradiated ingredi- ents, such as spices. -other pasteurizing systems other technologies using high-intensity pulsed light or electron beams have also been approved by the fda. -like irradiation, these technologies kill microorganisms and extend the shelf life of foods without dimin- ishing their nutrient content. -in summary millions of people suffer mild to life-threatening symptoms caused by food- borne illnesses (review table 19-1). -as the how to on pp. -670 671 describes, most of these illnesses can be prevented by storing and cooking foods at their proper temperatures and by preparing them in sanitary conditions. -irradia- tion of certain foods protects consumers from foodborne illnesses, but it also raises some concerns. -nutritional adequacy of foods and diets in years past, when most foods were whole and farm fresh, the task of meeting nu- trient needs primarily involved balancing servings from the various food groups. -to- day, however, foods have changed. -many new foods are available to appeal to consumers demands for convenience and flavor, but not necessarily to deliver a bal- anced assortment of needed nutrients. -obtaining nutrient information to help consumers find their way among these foods and combine them into health- ful diets, the fda has developed extensive nutrition labeling regulations, as chap- ter 2 described. -in addition, the usda s dietary guidelines help consumers eat to stay 674 chapter 19 healthy, and the mypyramid food guide helps them to put those recommendations into practice (see chapter 2). -minimizing nutrient losses in addition to selecting nutritious foods and preparing them safely, consumers can improve their nutritional health by learning to store and cook foods in ways that minimize nutrient losses. -water-soluble vitamins are the most vulnerable of the nu- trients, but both vitamins and minerals can be lost when they dissolve in water that is then discarded. -fruits and vegetables contain enzymes that both synthesize and degrade vita- mins. -after a fruit or vegetable has been picked, vitamin synthesis stops, but degra- dation continues. -to slow the degradation of vitamins, most fruits and vegetables should be kept refrigerated until used. -(degradative enzymes are most active at warmer temperatures.) -some vitamins are easily destroyed by oxygen. -to minimize the destruction of vitamins, store fruits and vegetables that have been cut and juice that has been opened in airtight containers and refrigerate them. -water-soluble vitamins readily dissolve in water. -to prevent losses during wash- ing, wash fruits and vegetables before cutting. -to minimize losses during cooking, steam or microwave vegetables. -alternatively, use the cooking water when prepar- ing meals such as casseroles and soups. -finally, keep in mind that most vitamin losses are not catastrophic and that a law of diminishing returns operates. -do not fret over small losses or waste time that may be valuable in improving your health in other ways. -be assured that if you start with plenty of fruits and vegetables and are reasonably careful in their storage and preparation, you will receive a sufficient supply of all the nutrients they provide. -in summary in the marketplace, food labels, the dietary guidelines, and the mypyramid food guide all help consumers learn about nutrition and how to plan healthy diets. -at home, consumers can minimize nutrient losses from fruits and veg- etables by refrigerating them, washing them before cutting them, storing them in airtight containers, and cooking them for short times in minimal water. -environmental contaminants concern about environmental contamination of foods is growing as the world be- comes more populated and more industrialized. -industrial processes pollute the air, water, and soil. -plants absorb the contaminants, and people consume the plants (grains, vegetables, legumes, and fruits) or the meat and milk products from live- stock that have eaten the plants. -similarly, polluted water contaminates the fish and other seafood that people eat. -environmental contaminants present in air, water, and foods find their way into our bodies and have the potential to cause numerous health problems.14 contaminants: substances that make a food impure and unsuitable for ingestion. -persistence: stubborn or enduring continuance; with respect to food contaminants, the quality of persisting, rather than breaking down, in the bodies of animals and human beings. -harmfulness of environmental contaminants the potential harmfulness of a contaminant depends in part on its persistence the extent to which it lingers in the environment or in the body. -some contaminants in the environment are short-lived because microorganisms or agents such as sun- light or oxygen can break them down. -some contaminants in the body may linger consumer concerns about foods and water 675 for only a short time because the body rapidly excretes them or metabolizes them to harmless compounds. -these contaminants present little cause for concern. -some contaminants, however, resist breakdown and can accumulate. -each level of the food chain, then, has a greater concentration than the one below (bioaccumu- lation). -figure 19-5 shows how bioaccumulation leads to high concentrations of toxins in people at the top of the food chain. -contaminants enter the environment in various ways. -accidental spills are rare but can have devastating effects. -more commonly, small amounts are released over long periods. -the following paragraphs describe how three contaminants found their way into the food supply in the past. -the first example involves a heavy metal; the others involve organic halogens. -methylmercury a classic example of acute contamination occurred in 1953 when a number of people in minamata, japan, became ill with a disease no one had seen before. -by 1960, 121 cases had been reported, including 23 in infants. -mor- tality was high; 46 died, and the survivors suffered blindness, deafness, lack of coor- dination, and intellectual deterioration. -the cause was ultimately revealed to be methylmercury contamination of fish from the bay where these people lived. -the infants who contracted the disease had not eaten any fish, but their mothers had, and even though the mothers exhibited no symptoms during their pregnancies, the poison affected their unborn babies. -manufacturing plants in the region were dis- charging mercury-containing waste into the waters of the bay, the mercury was reminder: a heavy metal is any of a num- ber of mineral ions such as mercury and lead, so called because they are of rela- tively high atomic weight. -many heavy metals are poisonous. -food chain: the sequence in which living things depend on other living things for food. -bioaccumulation: the accumulation of contaminants in the flesh of animals high on the food chain. -organic halogens: an organic compound containing one or more atoms of a halogen fluorine, chlorine, iodine, or bromine. -figure 19-5 bioaccumulation of toxins in the food chain this example features fish as the food for human consumption, but bioaccumulation of toxins occurs on land as well when cows, pigs, and chickens eat or drink contaminated foods or water. -key: toxic chemicals 4 3 2 1 if none of the chemicals are lost along the way, people ultimately receive all of the toxic chemicals that were present in the original plants and plankton. -level 4 a 150-pound person contaminants become further concentrated in larger fish that eat the small fish from the lower part of the food chain. -level 3 100 pounds of fish-eating fish such as lake trout, walleye, and bass contaminants become more concentrated in small fish that eat the plants and plankton. -level 2 a few tons of plankton-eating fish such as bluegill, perch, stream trout, and smelt plants and plankton at the bottom of the food chain become contaminated with toxic chemicals, such as methylmercury (shown as red dots). -level 1 several tons of producer organisms (plant and animal plankton) 676 chapter 19 because albacore ( white ) tuna has more mercury than canned light tuna, consumers should limit their intake to no more than 6 ounces of albacore tuna per week. -for perspective, 1 ppm (part per million) is equivalent to about 1 minute in 2 years or 1 cent in $10,000. -fish relatively high in mercury: tilefish, swordfish, king mackerel, shark fish relatively low in mercury: cod, haddock, pollock, salmon, sole, tilapia most shellfish pregnant and lactating women and young children should avoid: tilefish (also called golden snapper or golden bass), swordfish, king mackerel, shark and limit weekly consumption to: 12 oz (cooked or canned) commercial fish and shellfish (such as shrimp, canned light tuna, salmon, pollock, and catfish) 6 oz (cooked or canned) white albacore tuna pbb (polybrominated biphenyl) and pcb (polychlorinated biphenyl): toxic organic compounds used in pesticides, paints, and flame retardants. -turning into methylmercury, and the fish in the bay were accumulating this poison in their bodies. -some of the affected families had been eating fish from the bay every day. -o i g g u r r a f w e h t t a m pbb and pcb in 1973, half a ton of pbb (polybrominated biphenyl), a toxic organic compound, was accidentally mixed into some livestock feed that was dis- tributed throughout the state of michigan. -the chemical found its way into millions of animals and then into the people who ate the meat. -the seriousness of the acci- dent came to light when dairy farmers reported that their cows were going dry, aborting their calves, and developing abnormal growths on their hooves. -although more than 30,000 cattle, sheep, and swine and more than a million chickens were destroyed, an estimated 97 percent of michigan s residents had been exposed to pbb. -some of the exposed farm residents suffered nervous system aberrations and liver disorders. -a similar accident occurred in 1979 when pcb (polychlorinated biphenyls) contaminated rice oil in taiwan. -women who had eaten the tainted rice oil gave birth to children with developmental problems. -decades later, young men who were exposed to pcb during gestation have reduced fertility. -the interactive effects of pcb and mercury are especially damaging to brain functions such as balance and coordination.15 guidelines for consumers how much of a threat do environmental contaminants pose to the food supply? -for the most part, the hazards appear to be small. -the fda regulates the presence of contaminants in foods and requires foods with unsafe amounts to be removed from the market. -similarly, health agencies may issue advisories informing consumers about the potential dangers of eating contaminated foods. -most recently, mercury poisoning has aroused concerns even at levels one- tenth of those in the minamata catastrophe. -virtually all fish have at least trace amounts of mercury (on average, 0.12 parts per million). -fish and other seafood are the main source of dietary mercury.16 mercury, pcb, chlordane, dioxins, and ddt are the toxins most responsible for fish contamination, but mercury leads the list by threefold.17 review figure 19-5 (p. 675) and notice how toxins such as mercury become more concentrated in animals and in people high in the food chain. -because of bioaccumulation, large gamefish at the top of the aquatic food chain generally have the highest concentrations of mercury (ten times the average). -consumers who enjoy eating these fish should select the smaller, younger ones (within legal limits). -also because of bioaccumulation, the concentrations in fish may be a mil- lion times higher than the concentrations in the water itself. -the epa regulates commercial fishing to help ensure that fish destined for con- sumption in the united states meet safety standards for mercury and other con- taminants. -farm-raised fish usually have lower concentrations of mercury than fish caught in the wild. -consequently, most consumers in the united states are not in danger of receiving harmful levels of mercury from fish. -pregnant and lactating women and young children are most vulnerable be- cause mercury toxicity damages the developing brain.18 however, they are also likely to benefit from consuming seafood rich in omega-3 fatty acids. -to receive the benefits and minimize the risks, pregnant and lactating women and young chil- dren can safely consume up to 12 ounces of seafood per week.19 in addition, they should limit their intake of albacore tuna and avoid eating large predatory fish al- together. -blood levels of mercury in young children and women of child-bearing age are currently below levels of concern.20 what about the noncommercial fish a person catches from a local lake, river, or ocean? -after all, it s almost impossible to tell whether water is contaminated with- out sophisticated equipment. -each state monitors its waters and issues advisories to inform the public if chemical contaminants have been found in the local fish. -to consumer concerns about foods and water 677 find out whether a fish advisory has been posted in your region, call the local or state environmental health department. -all things considered, fish continue to support a healthy diet, providing valu- able protein, omega-3 fatty acids, and minerals. -for most adults, the benefits of protecting against heart disease outweigh the risks of consuming seafood regularly. -ideally, consumers would select fish with high omega-3 fatty acids and low mer- cury.21 in addition, they should select a variety of seafood to reduce the risk of ex- posure to contaminants from a single source. -in summary environmental contamination of foods is a concern, but so far, the hazards appear relatively small. -in all cases, two principles apply. -first, remain alert to the possibility of contamination of foods, and keep an ear open for public health announcements and advice. -second, eat a variety of foods. -varying food choices is an effective defensive strategy against the accumulation of tox- ins in the body. -each food eaten dilutes contaminants that may be present in other components of the diet. -natural toxicants in foods consumers concerned about food contamination may think that they can elim- inate all poisons from their diets by eating only natural foods. -on the con- trary, nature has provided plants with an abundant array of toxicants. -a few examples will show how even natural foods may contain potentially harmful substances. -they also show that although the potential for harm exists, actual harm rarely occurs. -poisonous mushrooms are a familiar example of plants that can be harmful when eaten. -few people know, though, that other commonly eaten foods contain substances that can cause illnesses. -cabbage, turnips, mustard greens, kale, brus- sels sprouts, cauliflower, broccoli, kohlrabi, and radishes contain small quantities of goitrogens compounds that can enlarge the thyroid gland. -eating exception- ally large amounts of goitrogen-containing vegetables can aggravate a preexisting thyroid problem, but it usually does not initiate one. -lima beans and fruit seeds such as apricot pits contain cyanogens inactive compounds that produce the deadly poison cyanide upon activation by a specific plant enzyme. -for this reason, many countries restrict commercially grown lima beans to those varieties with the lowest cyanogen contents. -as for fruit seeds, they are seldom deliberately eaten. -an occasional swallowed seed or two presents no danger, but a couple of dozen seeds can be fatal to a small child. -perhaps the most infamous cyanogen in seeds is laetrile a compound erroneously repre- sented as a cancer cure. -true, laetrile kills cancer, but only at doses that kill the person, too. -the combination of cyanide poisoning and lack of medical attention is life-threatening. -the humble potato contains many natural poisons including solanine, a pow- erful narcotic-like substance. -the small amounts of solanine normally found in po- tatoes are harmless, but solanine is toxic and presents a hazard when consumed in large quantities. -physical symptoms of solanine poisoning include headache, vom- iting, abdominal pain, diarrhea, and fever; neurological symptoms include apa- thy, restlessness, drowsiness, confusion, stupor, hallucinations, and visual disturbances. -solanine production increases when potatoes are improperly stored in the light and in either very cold or fairly warm places. -cooking does not destroy solanine, but because most of a potato s solanine is in the green layer that develops just beneath the skin, it can be peeled off, making the potato safe to eat. -fish relatively high in omega-3 fatty acids and low in mercury: salmon, herring, sardines, shad, lake trout, mackerel, whitefish, flounder/sole, pollock solanine (soh-lah-neen): a poisonous narcotic-like substance present in potato peels and sprouts. -678 chapter 19 as many as 400 varieties of fruits and vegeta- bles are imported from other countries. -pesticides: chemicals used to control insects, weeds, fungi, and other pests on plants, vegetables, fruits, and animals. -used broadly, the term includes herbicides (to kill weeds), insecticides (to kill insects), and fungicides (to kill fungi). -residues: whatever remains. -in the case of pesticides, those amounts that remain on or in foods when people buy and use them. -tolerance level: the maximum amount of a residue permitted in a food when a pesticide is used according to label directions. -in summary natural toxicants include the goitrogens in cabbage, cyanogens in lima beans, and solanine in potatoes. -these examples of naturally occurring toxi- cants illustrate two familiar principles. -first, any substance can be toxic when consumed in excess. -second, poisons are poisons, whether made by people or by nature. -remember: it is not the source of a chemical that makes it haz- ardous, but its chemical structure and the quantity consumed. -pesticides the use of pesticides in agriculture is controversial. -they help to ensure the sur- vival of crops, but they leave residues in the environment and on some of the foods we eat. -hazards and regulation of pesticides ideally, a pesticide destroys the pest and quickly degenerates to nontoxic products without accumulating in the food chain. -then, by the time consumers eat the food, no harmful residues remain. -unfortunately, no such perfect pesticide exists. -as new pesticides are developed, government agencies assess their risks and benefits and vigilantly monitor their use. -hazards of pesticides pesticides applied in the field may linger on the foods. -health risks from pesticide exposure are probably small for healthy adults, but chil- dren, the elderly, and people with weakened immune systems may be vulnerable to some types of pesticide poisoning. -to protect infants and children, government agencies set a tolerance level for each pesticide by first identifying foods that chil- dren commonly eat in large amounts and then considering the effects of pesticide exposure during each developmental stage.22 s e g a m i y t t e g / k n a b e g a m i e h t / i l l a v a c o l e g n a regulation of pesticides consumers depend on the epa and the fda to keep pesticide use within safe limits. -these agencies evaluate the risks and benefits of a pesticide s use by asking such questions as: how dangerous is it? -how much residue is left on the crop? -how much harm does the pesticide do to the environment? -how necessary is it? -what are the alternatives to its use? -if the pesticide is approved, the epa establishes a tolerance level for its presence in foods, well below the level at which it could cause any conceivable harm. -toler- ance regulations also state the specific crops to which each pesticide can be ap- plied. -if a pesticide is misused, growers risk fines, lawsuits, and destruction of their crops. -once tolerances are set, the fda enforces them by monitoring foods and live- stock feeds for the presence of pesticides. -over the past several decades of testing, the fda has seldom found residues above tolerance levels, so it appears that pesti- cides are generally used according to regulations. -minimal pesticide use means lower costs for growers. -in addition to costs, many farmers are also concerned about the environment, the quality of their farmland, and a safe food supply. -where violations are found, they are usually due to unusual weather conditions, use of unapproved pesticides, or misuse for example, application of a particular pesticide to a crop for which it has not been approved. -pesticides from other countries because other countries may not have the same pesticide regulations as the united states and canada, imported foods may contain both pesticides that have been banned and permitted pesticides at concen- trations higher than are allowed in domestic foods. -a loophole in federal regulations allows u.s. companies to manufacture and sell, to other countries, pesticides that are banned in this country. -the banned pesticides then return to the united states on imported foods a circuitous route that concerned consumers have called the consumer concerns about foods and water 679 circle of poison. -federal inspectors sample imported foods and refuse entry if they are found to contain illegal pesticide residues. -the united states, mexico, and canada work together to establish a pesticide policy for all of north america. -monitoring pesticides the fda collects and analyzes samples of both domestic and imported foods. -if the agency finds samples in violation of regulations, it can seize the products or order them destroyed. -the fda may also invoke a certification requirement that forces manufacturers, at their own expense, to have their foods periodically inspected and certified safe by an independent testing agency. -individual states also scan for pesti- cides (as well as for industrial chemicals) and provide information to the fda. -food in the fields in addition to its ongoing surveillance, the fda conducts se- lective surveys to determine the presence of particular pesticides in specific crops. -for example, one year the agency searched for aldicarb in potatoes, captan in cherries, and diaminozide (the chemical name for alar) in apples, among others. -the actions taken that year required several certifications. -thus one shipper in australia had to certify apples; one in canada, peppers; one in costa rica, chayotes. -all grapes from mexico had to be certified and so did all mangoes from anywhere. -this shows, inci- dentally, how many foods come from abroad not only those already named, but hundreds more and that the fda monitors them as carefully as it does the domes- tic food supply. -food on the plate in addition to monitoring foods in the field for pesticides, the fda also monitors people s actual intakes. -the agency conducts the total diet study (sometimes called the market basket survey ) to estimate the dietary intakes of pesticide residues by eight age and gender groups from infants to senior citizens. -four times a year, fda surveyors buy more than 200 foods from u.s. grocery stores, each time in several cities. -they prepare the foods table ready and then analyze them not only for pesticides, but also for essential minerals, industrial chemicals, heavy metals, and radioactive materials. -in all, the survey reports on over 10,000 samples a year, and recently more than half the samples have been imported foods. -most heavily sampled are fresh vegetables, fruits, and dairy products. -the total diet study provides a direct estimate of the amounts of pesticide residues that remain in foods as they are usually eaten after they have been washed, peeled, and cooked. -the fda finds the intake of almost all pesticides to be less than 1 percent of the amount considered acceptable. -the amount considered acceptable is the daily intake of a chemical which, if ingested over a lifetime, ap- pears to be without appreciable risk. -all in all, these findings confirm the safety of the u.s. food supply. -consumer concerns despite these reassuring reports, consumers still worry that food monitoring may not be adequate. -for one thing, manufacturers develop new pesticides all the time. -for another, as described earlier, other countries use pesticides that are illegal for use here. -for still another, although the regulations may protect u.s. foods adequately, they may not necessarily protect the environment or the people who work in the fields. -concerns over poisoning of soil, waterways, wildlife, and workers may well be valid. -the fda does not sample all food shipments or test for all pesticides in each sam- ple. -the fda is a monitoring agency, and as such, it cannot, nor can it be expected to, guarantee 100 percent safety in the food supply. -instead, it sets standards so that substances do not become a hazard, checks enough samples to adequately assess average food safety, and acts promptly when problems or suspicions arise. -minimizing risks whether consumers ingest pesticide residues depends on a num- ber of factors. -how much of a given food does the consumer eat? -what pesticide was s e g a m i y t t e g / l l a h e s i a l b - n a e j washing fresh fruits and vegetables removes most, if not all, of the pesticide residues that might have been present. -without appreciable risk means practical certainty that injury will not result even after a lifetime of exposure. -certification: the process in which a private laboratory inspects shipments of a product for selected chemicals and then, if the product is free of violative levels of those chemicals, issues a guarantee to that effect. -680 chapter 19 people can grow organic crops when their gar- dens or farms are relatively small. -organic foods that have met usda stan- dards may use this seal on their labels. -organic: in agriculture, crops grown and processed according to usda regulations defining the use of fertilizers, herbicides, insecticides, fungicides, preservatives, and other chemical ingredients. -used on it? -how much was used? -how long ago was the food last sprayed? -did en- vironmental conditions promote pest growth or pesticide breakdown? -how well was the produce washed? -was it peeled or cooked? -with so many factors, consumers cannot know for sure whether pesticide residues remain on foods, but they can min- imize their risks by following the guidelines offered in the how to feature below. -the food supply is protected well enough that consumers who take these precau- tions can feel secure that the foods they eat are safe. -i s b r o c / y e l l e k s l e i r a alternatives to pesticides the use of pesticides has helped to generate higher crop yields that feed the world and protect against diseases transmitted by insects. -still, many consumers are leery. -to feed a nation while using fewer pesticides re- quires creative farming methods. -highlight 19 describes how scientists can geneti- cally alter plants to enhance their production of natural pesticides, and highlight 20 presents alternative, or sustainable, agriculture methods. -these methods include such practices as rotating crops, releasing organisms into fields to destroy pests, and planting nonfood crops nearby to kill pests or attract them away from the food crops. -for example, releasing sterile male fruit flies into orchards helps to curb the population growth of these pests; some flowers, such as marigolds, release natural insecticides and are often planted near crops such as tomatoes. -such alternative farming methods are more labor-intensive and may produce smaller yields than conventional methods, at least initially. -over time, though, by eliminating expen- sive pesticides, fertilizers, and fuels, these alternatives may actually cut costs more than they cut yields. -organically grown crops alternative methods are especially useful for farmers who want to produce and market organic crops that are grown and processed ac- cording to usda regulations defining the use of synthetic fertilizers, herbicides, in- secticides, fungicides, preservatives, and other chemical ingredients. -similarly, meat, poultry, eggs, and dairy products may be called organic if the livestock has been raised according to usda regulations defining the grazing conditions and the use of organic feed, hormones, and antibiotics. -in addition, producers may not claim products are organic if they have been irradiated, genetically engineered, or grown with fertilizer made from sewer sludge. -figure 19-6 shows examples of food labels for products using organic ingredients. -most organic foods are marked as such, but consumers can also learn how fruits and vegetables were grown by reading the product code on produce stickers. -codes for conventionally grown produce are four digits. -regular bananas, for example, have the code 4011. codes for organic produce are five digits and begin with 9. how to prepare foods to minimize pesticide residues to remove or reduce any pesticide residues from foods: trim the fat from meat, and remove the skin from poultry and fish; discard fats and oils in broths and pan drippings. -(pesticide residues concentrate in the animal s fat.) -select fruits and vegetables that do not have holes. -peel waxed fruits and vegetables; waxes don t wash off and can seal in pesticide residues. -peel vegetables such as carrots and fruits such as apples when appropriate. -(peel- ing removes pesticides that remain in or on the peel, but also removes fibers, vitamins, and minerals.) -eat a variety of foods to minimize expo- wash fresh produce in warm running sure to any one pesticide. -water. -use a scrub brush, and rinse thor- oughly. -use a knife to peel an orange or grape- fruit; do not bite into the peel. -discard the outer leaves of leafy vegeta- bles such as cabbage and lettuce. -consider buying certified organic foods. -information is available from the epa s national pesticide hotline (800 858- pest). -figure 19-6 food labels for organic products consumer concerns about foods and water 681 e r u t l u c i r g a f o t n e m t r a p e d s e t a t s d e t i n u foods made with 100 percent organic ingredi- ents may claim 100% organic and use the seal. -foods made with at least 95 percent organic ingredients may claim organic and use the seal. -foods made with at least 70 percent organic ingredients may list up to three of those ingredients on the front panel. -foods made with less than 70 percent organic ingredients may list them on the side panel, but cannot make any claims on the front. -(thus the product code for organic bananas is 94011.) -codes for genetically modi- fied produce are also five digits and begin with 8. -(genetically modified bananas are given the product code 84011.) -implied in the marketing of organic foods is that organic products are safer or healthier for consumers than those grown using other methods, which may not be the case. -using unprocessed animal manure as an organic fertilizer, for example, may transmit bacteria, such as e. coli, to human beings. -both organic and conven- tional methods may have advantages and disadvantages, and consumers must re- main informed. -pesticide residues in organic foods are substantially lower than in convention- ally grown foods.23 as mentioned earlier, infants and children may be particularly vulnerable to the effects of pesticides. -to determine whether organic foods might re- duce their exposure to pesticides, children were given a five-day diet composed en- tirely of organic foods.24 before, during, and after the organic diet period, researchers tested the children s urine for chemicals known to arise from the inges- tion of common pesticides. -the results were dramatic and immediate: the concen- trations of chemicals fell and remained low during the organic diet and increased again when the conventional diet resumed. -are organic foods nutritionally superior to conventional foods? -any nutrient dif- ferences reported have been within the range that normally occurs in crops. -lim- ited research suggests foods produced organically have increased amounts of some phytochemicals.25 in summary pesticides can safely improve crop yields when used according to regulations, but they can also be hazardous when used inappropriately. -the fda tests both domestic and imported foods for pesticide residues in the fields and in market basket surveys of foods prepared table ready. -consumers can minimize their ingestion of pesticide residues on foods by following the suggestions in the how to on p. 680. alternative farming methods may allow farmers to grow crops with few or no pesticides. -. -c n i s o i d u t s a r a l o p many consumers are willing to pay a little more for organic produce. -682 chapter 19 . -c n i s o i d u t s a r a l o p food additives additives confer many benefits on foods. -some reduce the risk of foodborne illness (for example, nitrites used in curing meat prevent poisoning from the botulinum toxin). -others enhance nutrient quality (as in vitamin d fortified milk). -most addi- tives are preservatives that help prevent spoilage during the time it takes to deliver foods long distances to grocery stores and then to kitchens. -some additives simply make foods look and taste good. -intentional additives are put into foods on purpose, whereas indirect additives may get in unintentionally before or during processing. -this discussion begins with the regulations that govern additives, then presents intentional additives class by class, and finally goes on to say a word about the indirect additives. -regulations governing additives the fda s concern with additives hinges primarily on their safety. -to receive permis- sion to use a new additive in food products, a manufacturer must satisfy the fda that the additive is: effective (it does what it is supposed to do) detectable and measurable in the final food product safe (when fed in large doses to animals under strictly controlled conditions, it causes no cancer, birth defects, or other injury) on approving an additive s use, the fda writes a regulation stating in what amounts and in what foods the additive may be used. -no additive receives perma- nent approval, and all must undergo periodic review. -the gras list many familiar substances are exempted from complying with the fda s approval procedure because they are generally recognized as safe (gras), based either on their extensive, long-term use in foods or on current scien- tific evidence. -several hundred substances are on the gras list, including such items as salt, sugar, caffeine, and many spices. -whenever substantial scientific evidence or public outcry has questioned the safety of any substance on the gras list, it has been reevaluated. -if a legitimate question has been raised about a substance, it has been removed or reclassified. -meanwhile, the entire gras list is subjected to ongo- ing review. -the delaney clause one risk that the u.s. law on additives refuses to tolerate at any level is the risk of cancer. -to remain on the gras list, an additive must not have been found to be a carcinogen in any test on animals or human beings. -the de- laney clause (the part of the law that states this criterion) is uncompromising in addressing carcinogens in foods and drugs; in fact, it has been under fire for many years for being too strict and inflexible. -the delaney clause is best understood as a product of a different historical era. -it was adopted decades ago at a time when scientists knew less about the relation- ships between carcinogens and cancer development. -at that time, most sub- stances were detectable in foods only in relatively large amounts, such as parts per thousand. -today, scientific understanding of cancer has progressed, and technol- ogy has advanced so that carcinogens in foods can be detected even when they are present only in parts per billion or even per trillion. -earlier, zero risk may have seemed attainable, but today we know it is not: all substances, no matter how pure, can be shown to be contaminated at some level with one carcinogen or an- other. -for these reasons, the fda prefers to deem additives (and pesticides and other contaminants) safe if lifetime use presents no more than a one-in-a-million risk of cancer to human beings. -thus, instead of the zero-risk policy of the de- laney clause, the fda uses a negligible-risk standard, sometimes referred to as a de minimis rule. -without additives, bread would quickly get moldy, and salad dressing would go rancid. -for perspective, one part per trillion is equivalent to about one grain of sugar in an olympic-size swimming pool; or 1 sec- ond in 32,000 years; or one hair on 10 mil- lion heads, assuming none are bald. -the de minimis rule defines risk as a cancer rate of less than one cancer per million people exposed to a contaminant over a 70-year lifetime. -additives: substances not normally consumed as foods but added to food either intentionally or by accident. -preservatives: antimicrobial agents, antioxidants, and other additives that retard spoilage or maintain desired qualities, such as softness in baked goods. -generally recognized as safe (gras): food additives that have long been in use and are believed safe. -first established by the fda in 1958, the gras list is subject to revision as new facts become known. -delaney clause: a clause in the food additive amendment to the food, drug, and cosmetic act that states that no substance that is known to cause cancer in animals or human beings at any dose level shall be added to foods. -consumer concerns about foods and water 683 margin of safety whatever risk level is permitted, actual risks must be deter- mined by experiments. -to determine risks posed by an additive, researchers feed test animals the additive at several concentrations throughout their lives. -the additive is then permitted in foods in amounts 100 times below the lowest level that is found to cause any harmful effect, that is, at a 1/100 margin of safety. -in many foods, naturally occurring substances occur with narrower margins of safety. -even nutrients pose risks at dose levels above those recommended and normally consumed: for young adults, the recommendation for vitamin d is only 1/10 of the upper level. -people consume common table salt daily in amounts only three to five times less than those that pose a hazard. -risks versus benefits of course, additives would not be added to foods if they only presented risks. -additives are in foods because they offer benefits that outweigh the risks they present, or make the risks worth taking. -in the case of color additives that only enhance the appearance of foods but do not improve their health value or safety, no amount of risk may be deemed worth taking. -in contrast, the fda finds that it is worth taking the small risks associated with the use of nitrites on meat products, for example, because nitrites inhibit the formation of the deadly botu- linum toxin. -the choice involves a compromise between the risks of using additives and the risks of doing without them. -it is the manufacturers responsibility to use only the amounts of additives that are necessary to achieve the needed effect, and no more. -the fda also requires that additives not be used: to disguise faulty or inferior products to deceive the consumer when they significantly destroy nutrients when their effects can be achieved by economical, sound manufacturing processes intentional food additives intentional food additives are added to foods to give them some desirable char- acteristic: resistance to spoilage, color, flavor, texture, stability, or nutritional value. -table 19-3 presents an overview of additives, and the next sections describe additives people most often ask about. -antimicrobial agents foods can go bad in two ways. -one way is relatively harmless: by losing their flavor and attractiveness. -(additives to prevent this kind margin of safety: when speaking of food additives, a zone between the concentration normally used and that at which a hazard exists. -for common table salt, for example, the margin of safety is 1/5 (five times the amount normally used would be hazardous). -intentional food additives: additives intentionally added to foods, such as nutrients, colors, and preservatives. -table 19-3 intentional food additives food additive purpose common examples antimicrobial agents prevent microorganisms from growing salt, sugar, nitrites and nitrates (such as sodium nitrate) antioxidants colors flavors delay or prevent rancidity of fats and other damage to foods caused by oxygen vitamin c (erythorbic acid, sodium ascorbate), vitamin e (tocopherol), sulfites, bha and bht enhance appearance artificial: indigotine, erythrosine, tartrazine natural: annatto (yellow), caramel (yellowish brown), carotenoids (yellowish orange), dehydrated beets (reddish brown), grape skins (red, green) enhance taste salt, sugar, spices, artificial sweeteners, msg emulsifiers and gums thicken, stabilize, or otherwise improve the consistency nutrients (vitamins and minerals) improve the nutritive value emulsifiers: lecithin, alginates, mono- and diglycerides gums: agar, alginates, carrageenan, guar, locust bean, psyl- lium, pectin, xanthan gum, gum arabic, cellulose derivatives thiamin, niacin, riboflavin, folate, iron (in grain products); iodine (in salt); vitamins a and d (in milk); vitamin c and calcium (in fruit drinks); vitamin b12 (in vegetarian foods) 684 chapter 19 both salt and sugar act as preservatives by withdrawing water from food; microbes cannot grow without water. -sulfites appear on food labels as: sulfur dioxide sodium sulfite sodium bisulfite potassium bisulfite sodium metabisulfite potassium metabisulfite nitrites (nye-trites): salts added to food to prevent botulism. -one example is sodium nitrite, which is used to preserve meats. -nitrosamines (nye-trohs-uh-meens): derivatives of nitrites that may be formed in the stomach when nitrites combine with amines. -nitrosamines are carcinogenic in animals. -sulfites: salts containing sulfur that are added to foods to prevent spoilage. -bha and bht: preservatives commonly used to slow the development of off-flavors, odors, and color changes caused by oxidation. -. -c n i s o i d u t s a r a l o p of spoilage include antioxidants, discussed later.) -the other way is by becoming contaminated with microbes that cause foodborne illnesses, a hazard that justifies the use of antimicrobial agents. -the most widely used antimicrobial agents are ordinary salt and sugar. -salt has been used throughout history to preserve meat and fish; sugar serves the same pur- pose in canned and frozen fruits and in jams and jellies. -both exert their protective effect primarily by capturing water and making it unavailable to microbes. -other antimicrobial agents, the nitrites, are added to foods for three main pur- poses: to preserve color, especially the pink color of hot dogs and other cured meats; to enhance flavor by inhibiting rancidity, especially in cured meats and poultry; and to protect against bacterial growth. -in amounts smaller than those needed to confer color, nitrites prevent the growth of the bacteria that produce the deadly bot- ulinum toxin. -nitrites clearly serve a useful purpose, but their use has been controversial. -in the human body, nitrites can be converted to nitrosamines. -at nitrite levels higher than those used in food products, nitrosamine formation causes cancer in animals. -the food industry uses the minimal amount of nitrites necessary to achieve results, and nitrosamine formation has not been shown to cause cancer in human beings. -detectable amounts of nitrosamine-related compounds are found in malt bev- erages (beer) and cured meats (primarily bacon). -yet even the quantities found in beer and bacon hardly make a difference in a person s overall exposure to ni- trosamine-related compounds. -an average cigarette smoker inhales 100 times the nitrosamines that the average bacon eater ingests. -a beer drinker ingests twice as much as the bacon eater, but even so, nitrosamine exposure from new car interiors and cosmetics is higher than this. -antioxidants another way food can go bad is by exposure to oxygen (oxidation). -often, these changes involve no hazard to health, but they damage the food s ap- pearance, flavor, and nutritional quality. -oxidation is easy to detect when sliced ap- ples or potatoes turn brown or when oil goes rancid. -antioxidants prevent these reactions. -among the antioxidants approved for use in foods are vitamin c (ascor- bate) and vitamin e (tocopherol). -another group of antioxidants, the sulfites, cost less than the vitamins. -sul- fites prevent oxidation in many processed foods, alcoholic beverages (especially wine), and drugs. -because some people experience adverse reactions, the fda pro- hibits sulfite use on foods intended to be consumed raw, with the exception of grapes, and requires foods and drugs that contain sulfite additives to declare it on their labels. -for most people, sulfites pose no hazard in the amounts used in prod- ucts, but there is one more consideration sulfites destroy the b vitamin thiamin. -for this reason, the fda prohibits their use in foods that are important sources of the vitamin, such as enriched grain products. -two other antioxidants in wide use are bha and bht, which prevent rancidity in baked goods and snack foods. -* several tests have shown that animals fed large amounts of bht develop less cancer when exposed to carcinogens and live longer than controls. -apparently, bht protects against cancer through its antioxidant effect, which is similar to that of the antioxidant nutrients. -the amount of bht ingested daily from the u.s. diet, however, contributes little to the body s antioxidant defense system. -a caution: at intakes higher than those that protect against cancer, bht has produced cancer. -vitamins e and c remain the most important dietary antioxidants to strengthen defenses against cancer. -(see highlight 11 for a full discussion.) -colors only a few artificial colors remain on the fda s list of additives approved for use in foods a highly select group that has survived considerable testing. -colors derived from the natural pigments of plants must also meet standards of purity and safety. -examples of natural pigments commonly used by the food industry are the * bha is butylated hydroxyanisole; bht is butylated hydroxytoluene. -consumer concerns about foods and water 685 caramel that tints cola beverages and baked goods and the carotenoids that color margarine, cheeses, and pastas. -carotenoids are also added to the feed for farm- raised salmon, which deepens the pink flesh color. -artificial flavors and flavor enhancers natural flavors, artificial flavors, and flavor enhancers are the largest single group of food additives. -many foods taste wonderful because manufacturers have added the natural flavors of spices, herbs, essential oils, fruits, and fruit juices. -some spices, notably those used in mediter- ranean cooking, provide antioxidant protection as well as flavors. -often, natural flavors are used in combination with artificial flavors. -the sugar alternatives dis- cussed in highlight 4 are among the most widely used artificial flavor additives. -one of the best-known flavor enhancers is monosodium glutamate, or msg a sodium salt of the amino acid glutamic acid. -msg is used widely in a number of foods, especially asian foods, canned vegetables, soups, and processed meats. -besides enhancing the well-known sweet, salty, bitter, and sour tastes, msg itself may possess a pleasant flavor. -adverse reactions to msg known as the msg symptom complex may occur in people with asthma and in sensitive individ- uals who consume large amounts of msg, especially on an empty stomach. -other- wise, msg is considered safe for adults. -it is not allowed in foods designed for infants, however. -food labels require ingredient lists to itemize all additives, includ- ing msg. -texture and stability some additives help to maintain a desirable consistency in foods. -emulsifiers keep mayonnaise stable, control crystallization in syrups, keep spices dispersed in salad dressings, and allow powdered coffee creamer to dissolve easily. -gums are added to thicken foods and help form gels. -yeast may be added to provide leavening, and bicarbonates and acids may be used to control acidity. -nutrient additives as mentioned earlier, manufacturers sometimes add nutri- ents to fortify or maintain the nutritional quality of foods. -included among nutrient additives are the five nutrients added to grains (thiamin, riboflavin, niacin, folate, and iron), the iodine added to salt, the vitamins a and d added to milk, and the nu- trients added to fortified breakfast cereals. -a nutrient-poor food with nutrients added may appear to be nutrient-rich, but it is rich only in those nutrients chosen for addi- tion. -appropriate uses of nutrient additives are to: correct dietary deficiencies known to result in diseases restore nutrients to levels found in the food before storage, handling, and processing s e g a m i y t t e g / c s i d o t o h p color additives not only make foods attractive, but they identify flavors as well. -everyone agrees that yellow jellybeans should taste lemony and black ones should taste like licorice. -common foods containing acrylamide: balance the vitamin, mineral, and protein contents of a food in proportion to the energy content correct nutritional inferiority in a food that replaces a more nutritious tradi- tional food french fries potato chips breakfast cereals cookies as mentioned earlier, nutrients are sometimes also added for other purposes. -for ex- ample, vitamins c and e are used for their antioxidant properties, and beta- carotene and other carotenoids are sometimes used for color. -indirect food additives indirect or incidental additives find their way into foods during harvesting, pro- duction, processing, storage, or packaging. -incidental additives may include tiny bits of plastic, glass, paper, tin, and other substances from packages as well as chem- icals from processing, such as the solvent used to decaffeinate coffee. -the following paragraphs discuss six different types of indirect additives that sometimes make headline news. -acrylamide raw potatoes don t have it, but french fries do acrylamide, a com- pound that forms when carbohydrate-rich foods are cooked at high tempera- tures.26 apparently, acrylamide has been in foods ever since we started baking, monosodium glutamate (msg): a sodium salt of the amino acid glutamic acid commonly used as a flavor enhancer. -the fda classifies msg as a generally recognized as safe ingredient. -msg symptom complex: an acute, temporary intolerance reaction that may occur after the ingestion of the additive msg (monosodium glutamate). -symptoms include burning sensations, chest and facial flushing and pain, and throbbing headaches. -indirect or incidental additives: substances that can get into food as a result of contact during growing, processing, packaging, storing, cooking, or some other stage before the foods are consumed; sometimes called accidental additives. -686 chapter 19 a carcinogen is a substance that causes cancer, and a genotoxicant is a substance that mutates or damages genetic material. -quick test for using glass or ceramic con- tainers in a microwave oven: microwave the empty container for 1 min. -if it s warm, it s unsafe for the microwave. -if it s lukewarm, it s safe for short-term reheating in the microwave. -if it s cool, it s safe for long-term cooking in the microwave. -dioxins (dye-ock-sins): a class of chemical pollutants created as by-products of chemical manufacturing, incineration, chlorine bleaching of paper pulp, and other industrial processes. -dioxins persist in the environment and accumulate in the food chain. -bovine growth hormone (bgh): a hormone produced naturally in the pituitary gland of a cow that promotes growth and milk production; now produced for agricultural use by bacteria. -bovine = of cattle frying, and roasting, but only recently has its presence been analyzed.27 at high doses, acrylamide causes cancer and nerve damage in animals. -as such, scientists classify it as both a carcinogen and a genotoxicant, but quantities commonly found in foods appear to be well below the amounts that cause such damage. -the fda is currently investigating how acrylamide is formed in foods, how its formation can be limited, and whether its presence is harmful.28 microwave packaging some microwave products are sold in active packag- ing that helps to cook the food; for example, pizzas are often heated on a metalized film laminated to paperboard. -this film absorbs the microwave energy in the oven and reaches temperatures as high as 500 f. at such temperatures, packaging com- ponents migrate into the food. -for this reason, manufacturers must perform specific tests to determine whether materials are migrating into foods. -if they are, their safety must be confirmed by strict procedures similar to those governing intentional additives. -most microwave products are sold in passive packaging that is transparent to microwaves and simply holds the food as it cooks. -these containers don t get much hotter than the foods, but materials still migrate at high temperatures. -consumers should not reuse these containers in the microwave oven. -instead they should use only glass or ceramic containers designed for microwave ovens and avoid using disposable styrofoam or plastic containers such as those used for carryout or mar- garine. -plastic wrap has not been approved for use in microwave ovens, but if used, it should not touch the food. -dioxins coffee filters, milk cartons, paper plates, and frozen food packages, if made from bleached paper, can contaminate foods with minute quantities of dioxins compounds formed during chlorine treatment of wood pulp during paper manufacture. -dioxin contamination of foods from such products appears only in trace quantities in the parts-per-trillion range (recall, for perspective, that one part per trillion is equal to 1 second in 32,000 years). -such levels appear to present no health risks to people, but scientists recognize that dioxins are extremely toxic and are likely to cause cancer in humans.29 accordingly, the paper industry has reduced its use of chlorine to cut dioxin exposure; in the meantime, the fda has concluded that drinking milk from bleached-paper cartons presents no health hazard. -con- trary to e-mail warnings, plastics do not yield dioxins when broken down and diox- ins are not released from plastic wrap when microwaved.30 human exposure to dioxins comes primarily from foods such as beef, milk products, pork, fish, and shellfish.31 decaffeinated coffee many consumers have tried to eliminate caffeine from their diets by selecting decaffeinated coffee. -to remove caffeine from coffee beans, manufacturers often use methylene chloride in a process that leaves traces of the chemical in the final product. -the fda estimates that the average cup of coffee de- caffeinated this way contains about 0.1 part per million of methylene chloride, which seems to pose no significant threat. -a person drinking decaffeinated coffee containing 100 times as much methylene chloride every day for a lifetime has a one-in-a-million chance of developing cancer from it. -people are exposed to much more methylene chloride from other sources such as hair sprays and paint stripping solutions. -still, some consumers prefer either to return to caffeine or to select coffee decaffeinated in another way, perhaps by steam. -unfortunately, manufacturers are not required to state on their labels the type of decaffeination process used in their products. -many labels provide consumer-information telephone numbers for those who have such questions. -hormones hormones are a unique type of incidental additive in that their use is intentional, but their presence in the final food product is not. -the fda has ap- proved about a dozen hormones for use in food-producing animals, and the usda has established limits for residues allowed in meat products. -some ranchers in the united states treat cattle with bovine growth hormone (bgh). -hormone-treated animals produce leaner meats, and dairy cows produce consumer concerns about foods and water 687 more milk. -all cows make bgh naturally. -scientists can also genetically alter bac- teria to produce bgh, which allows laboratories to harvest huge quantities of the hormone and sell it to farmers as a drug. -genetic engineering practices such as this have aroused some consumer concerns (see highlight 19). -indeed, traces of bgh do remain in the meat and milk of both hormone-treated and untreated cows. -bgh residues have not been tested for safety in human beings because residues of the natural hormone have always been present in milk and meat, and the amount found in treated cows is within the range that can occur nat- urally. -furthermore, bgh, being a peptide hormone, is denatured by the heat used in processing milk and cooking meat, and it is also digested by enzymes in the gi tract. -if any bgh were to enter the bloodstream, it would have no effect because the chem- ical structures of animal growth hormones differ from those in human beings. -there- fore, bgh does not stimulate receptors for human growth hormone. -according to the national institutes of health, as currently used in the united states, meat and milk from treated cows are as safe as those from untreated cows. -whether hormones that have passed through the animals into feces and then contaminated the soil and wa- ter interfere with plants or animals in the environment remains controversial.32 antibiotics like hormones, antibiotics are also intentionally given to livestock, and residues may remain in the meats and milks. -consequently, people consuming these foods receive tiny doses of antibiotics regularly, and those with sensitivity to antibiotics may suffer allergic reactions.33 to minimize drug residues in foods, the fda requires a specified time between the time of medication and the time of slaughter to allow for drug metabolism and excretion. -of greater concern to the public s health is the development of antibiotic resist- ance, which occurs when antibiotics are overused. -physicians and veterinarians use an estimated 5 million pounds of antibiotics to treat infections in people and ani- mals, but farmers add five times as much to livestock feed to enhance growth. -not surprisingly, meat from these animals contains resistant bacteria. -such indiscrimi- nate use of antibiotics can be catastrophic to the treatment of disease in human be- ings. -antibiotics are less effective in treating people who are infected with resistant bacteria. -the fda continues to monitor the use of antibiotics in the food industry with the goal of ensuring that antibiotics remain effective in treating human disease. -in summary on the whole, the benefits of food additives seem to justify the risks associated with their use. -the fda regulates the use of the following intentional addi- tives: antimicrobial agents (such as nitrites) to prevent microbial spoilage; an- tioxidants (such as vitamins c and e, sulfites, and bha and bht) to prevent oxidative changes; colors (such as tartrazine) and flavor enhancers (such as msg) to appeal to senses; and nutrients (such as iodine in salt) to enrich or for- tify foods. -incidental additives sometimes get into foods during processing, but rarely present a hazard, although some processes such as treating livestock with hormones and antibiotics raise consumer concerns. -consumer concerns about water foods are not alone in transmitting diseases; water is guilty, too.34 in fact, cryp- tosporidium and cyclospora, commonly found in fresh fruits and vegetables, and vib- rio vulnificus, found in raw oysters, are commonly transmitted through contaminated water. -in addition to microorganisms, water may contain many of the same impu- rities that foods do: environmental contaminants, pesticides, and additives such as chlorine used to kill pathogenic microorganisms and fluoride used to protect against dental caries. -a glass of water is more than just h2o. -this discussion examines 688 chapter 19 water that is suitable for drinking is called potable (pot-ah-bul). -only 1% of all the earth s water is potable. -clean rivers represent irreplaceable water resources. -the sources of drinking water, harmful contaminants, and ways to ensure water safety. -sources of drinking water drinking water comes from two sources surface water and groundwater. -each source supplies water for about half of the population. -most major cities obtain their drinking water from surface water the water in lakes, rivers, and reservoirs. -surface water is readily contaminated because it is di- rectly exposed to acid rain, runoff from highways and urban areas, pesticide runoff from agricultural areas, and industrial wastes that are dumped directly into it. -sur- face water contamination is reversible, however, because fresh rain constantly re- places the water. -it is also cleansed to some degree by aeration, sunlight, and plants and microorganisms that live in it. -groundwater is the water in underground aquifers rock formations that are saturated with and yield usable water. -people who live in rural areas rely mostly on groundwater pumped up from private wells. -groundwater is contaminated more slowly than surface water, but also more permanently. -contaminants deposited on the ground migrate slowly through the soil before reaching groundwater. -once there, the contaminants break down less rapidly than in surface water due to the lack of aeration, sunlight, and aerobic microorganisms. -the slow replacement of groundwater also helps contaminants remain for a long time. -groundwater is es- pecially susceptible to contamination from hazardous waste sites, dumps and landfills, underground tanks storing gasoline and other chemicals, and improperly discarded household chemicals and solvents. -water systems and regulations public water systems treat water to remove contaminants that have been detected above acceptable levels. -during treatment, a disinfectant (usually, chlorine) is added to kill bacteria. -the addition of chlorine to public water is an important pub- lic health measure that appears to offer great benefits and small risks. -on the one hand, chlorinated water has eliminated such water-borne diseases as typhoid fever, which once ravaged communities, killing thousands of people. -on the other hand, it has been associated with a slight increase in bladder and rectal cancers and with contamination of the environment with the toxic by-product dioxin. -the epa is re- sponsible for ensuring that public water systems meet minimum standards for pro- tecting the public health. -* even safe water may have characteristics that some consumers find unpleasant. -most of these problems reflect the mineral content of the water. -for example, man- ganese and copper give water a metallic taste, and sulfur produces a rotten egg odor. -iron leaves a rusty brown stain on plumbing fixtures and laundry. -calcium and magnesium (commonly found in hard water ) build up in coffeemakers and hot water heaters. -similarly, soap is not easily rinsed away in hard water, leaving bathtubs and laundry looking dingy. -for these and other reasons, some consumers have adopted alternatives to the public water system. -home water treatments to ease concerns about the quality of drinking water, some people purchase home water-treatment systems. -because the epa does not cer- tify or endorse these water-treatment systems, consumers must shop carefully. -man- ufacturers offer a variety of units for removing contaminants from drinking water. -none of them removes all contaminants, and each has its own advantages and dis- advantages. -choosing the right treatment unit depends on the kinds of contami- nants in the water. -for example, activated carbon filters are particularly effective in removing chlorine, heavy metals such as mercury, and organic contaminants from s e g a m i y t t e g / c s i d o t o h p * the epa s safe drinking water hotline: (800) 426-4791. consumer concerns about foods and water 689 sediment; reverse osmosis, which forces pressurized water across a membrane, flushes out sodium, arsenic, and some microorganisms such as giardia; and distilla- tion systems, which boil water and condense the steam to water, remove contami- nants such as lead and kill microorganisms in the process. -therefore, before purchasing a home water-treatment unit, a consumer must first determine the qual- ity of the water. -in some cases, a state or county health department will test water samples or can refer the consumer to a certified laboratory. -bottled water despite the higher cost, many people turn to bottled water as an alternative to tap water. -the average consumer drinks more than 20 gallons of bottled water a year. -bottled water is classified as a food, so it is regulated nation- wide by the fda and locally by state health and environmental agencies. -the fda has established quality and safety standards for bottled drinking waters com- patible with those set by the epa for public water systems. -in addition, all bottled waters must be processed, packaged, and labeled in accordance with fda regula- tions. -its quality varies among brands because of variations in the source water used and company practices. -labels on bottled water must identify the water s source. -approximately 75 per- cent of bottled waters derive from protected groundwater (from springs or wells) that has been disinfected with ozone rather than chlorine. -ozone kills microorgan- isms, then disintegrates spontaneously into water and oxygen, leaving behind no toxic by-products. -other bottled waters derive from municipal tap water that has been treated by carbon filtration to remove chlorine and inorganic compounds. -bottled waters may also be treated by reverse osmosis or ion exchange to remove inorganic compounds. -alternatively, the water may be distilled or deionized to re- move dissolved solids. -most bottled waters do not contain fluoride; consequently, they do not provide the tooth protection of fluoridated water from community pub- lic water systems. -despite government regulations, some contamination has been detected in some bottled waters. -although the amounts of most contaminants found in bottled waters are probably insignificant, consumers should be aware that bottled water is not al- ways purer than the water from their taps. -as a safeguard, the fda recommends that bottled water be handled like other foods and be refrigerated after opening. -protection of drinking water is the subject of an ongoing battle between environ- mentalists and industry. -it may soon become a source of conflict between the world s nations as the population continues to grow and the renewable water sup- ply remains constant. -estimates are that within the next 50 years, half of the world s people will not have enough clean water to meet their needs. -to avert this potential calamity, we must take active steps to conserve water, clean polluted wa- ter, desalinate seawater, and curb population growth. -the how to on the next page describes how to disinfect bacterially contaminated water. -in summary like foods, water may contain infectious microorganisms, environmental con- taminants, pesticide residues, and additives. -the epa monitors the safety of the public water system, but many consumers choose home water-treatment systems or bottled water instead of tap water. -as this chapter said at the start, supplying food safely to hundreds of millions of peo- ple is an incredible challenge one that is met, for the most part, with incredible ef- ficiency. -the following chapter describes a contrasting situation that of the food supply not reaching the people. -690 chapter 19 how to disinfect water in an extreme emergency, when safe water is unavailable, the epa advises disinfecting water for drinking, cooking, and brushing teeth. -well water is safest, but lake or stream water may be used. -clear water is most easily treated; filter cloudy or discolored water through sev- eral layers of clean cloth or a coffee filter before disinfecting. -the preferred method of disinfecting water is to boil it vigorously for at least one minute to kill all disease-causing organ- isms. -if boiling is not possible, most dis- ease-causing microorganisms can be killed using chlorine or iodine disinfecting tablets available from drugstores and sporting good stores. -follow label directions. -alternatively, use chlorine-containing laundry bleach and follow the directions on the bottle. -if there are no directions, mix 5 drops of regular (not concentrated, scented, or color-safe) bleach with each quart of clear water. -if water is cloudy or colored, double the amount. -let water stand for at least 30 minutes before using it. -properly treated water smells slightly of chlorine; if no chlorine odor is present, repeat the dosage. -to remove the odor, pour water back and forth between clean containers to aerate it. -iodine tincture, a common first aid antiseptic for wounds, kills some disease-causing organisms, but it is less effective than chlorine. -add 5 drops of 2 percent iodine tincture to each quart of water (add 10 drops if water is cloudy). -let water stand for at least 30 minutes before using it. -www.thomsonedu.com/thomsonnow nutrition portfolio practicing food safety allows you to eat a variety of foods, with little risk of food- related illnesses. -review your food-handling practices and describe how effectively you wash your hands, utensils, and kitchen surfaces when preparing foods. -describe the steps you take to separate raw and cooked foods while storing and preparing them. -describe how you can ensure that you cook foods to a safe temperature and refrigerate perishable foods promptly. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 19, then to nutrition on the net. -get food safety tips from the government food safety information site or from the fight bac! -campaign of the partnership for food safety education: www.foodsafety.gov or www.fightbac.org learn more about foodborne illnesses from the national center for infectious diseases at the centers for disease control and prevention: www.cdc.gov/ncidod learn more about food irradiation from the international food information council: www.ific.org report adverse reactions to the fda s medwatch program at (800) 332-1088 or: www.fda.gov/medwatch get fish advisories from the environmental protection agency: www.epa.gov/ost/fish review tips from the environmental protection agency on methods of food buying and preparation that will help minimize pesticide exposure: www.epa.gov/pesticides/food learn about the various types of food thermometers and visit the canadian food inspection agency (cfia): how and when to use them from the usda thermy cam- paign: www.fsis.usda.gov/thermy find commonsense health tips for travelers at the centers for disease control and prevention site: www.cdc.gov/travel www.inspection.gc.ca learn more about food safety in the marketplace from the food safety and inspection service: www.usda.gov/fsis consumer concerns about foods and water 691 learn more about organic foods and national organic food learn more about safe drinking water from the standards from the national organic program: www.ams.usda.gov/nop environmental protection agency: www.epa.gov/ safewater find information on foodborne illnesses and safe food handling from the american dietetic association: www.homefoodsafety.org enjoy the humor and music of food toxicologist carl winter at: foodsafe.ucdavis.edu/music.html study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -c. fresh fruits and vegetables. -d. raw milk, seafood, meat, and eggs. -these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. to what extent does food poisoning present a real hazard to consumers eating u.s. foods? -how often does it occur? -(p. 664) 2. distinguish between the two types of foodborne illnesses and provide an example of each. -describe measures that help prevent foodborne illnesses. -(pp. -664 666, 670 671) 3. what special precautions apply to meats? -to seafood? -(pp. -668 671) 4. what is meant by a persistent contaminant of foods? -describe how contaminants get into foods and build up in the food chain. -(pp. -674 676) 5. what dangers do natural toxicants present? -(p. 677) 6. how do pesticides become a hazard to the food supply, and how are they monitored? -in what ways can people reduce the concentrations of pesticides in and on foods that they prepare? -(pp. -678 681) 7. what is the difference between a gras substance and a regulated food additive? -give examples of each. -name and describe the different classes of additives. -(pp. -682 685) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 692. -1. eating a contaminated food such as undercooked poultry or unpasteurized milk might cause a: a. food allergy. -b. food infection. -c. food intoxication. -d. botulinum reaction. -2. the temperature danger zone for foods ranges from: a. -(cid:4)20 f to 120 f. b. -0 f to 100 f. c. 20 f to 120 f. d. 40 f to 140 f. 3. examples of foods that frequently cause foodborne illness are: a. canned foods. -b. steaming-hot foods. -4. irradiation can help improve our food supply by: a. cooking foods quickly. -b. killing microorganisms. -c. minimizing the use of preservatives. -d. improving the nutrient content of foods. -5. solanine is an example of a(n): a. heavy metal. -b. artificial color. -c. natural toxicant. -d. animal hormone. -6. the standard that deems additives safe if lifetime use presents no more than a one-in-a-million risk of cancer is known as the: a. delaney clause. -b. zero-risk policy. -c. gras list of standards. -d. negligible-risk policy. -7. common antimicrobial additives include: a. salt and nitrites. -b. carrageenan and msg. -c. dioxins and sulfites. -d. vitamin c and vitamin e. 8. common antioxidants include: a. bha and bht. -b. tartrazine and msg. -c. sugar and vitamin e. d. nitrosamines and salt. -9. incidental additives that may enter foods during process- ing include: a. dioxins and bgh. -b. dioxins and folate. -c. beta-carotene and agar. -d. nitrites and irradiation. -10. chlorine is added to water to: a. protect against dental caries. -b. destroy harmful minerals such as lead and mercury. -c. kill pathogenic microorganisms. -d. remove the sulfur that produces a rotten egg odor. -692 chapter 19 references 1. b. bruemmer, food biosecurity, journal of the american dietetic association 103 (2003): 687-691; t. peregrin, bioterrorism and food safety: what nutrition professionals need to know to educate the american public, journal of the american dietetic association 102 (2002): 14, 16; food and drug adminis- tration, food security guidance: availability, federal register 67 (2002): 1224-1225; j. sobel, a. s. khan, and d. l. swerdlow, threat of a biological terrorist attack on the us food supply: the cdc perspective, lancet 359 (2002): 874-880. -2. centers for disease control and prevention, foodnet surveillance report for 2004, june 2006. -3. e. a. coleman and m. e. yergler, botulism, american journal of nursing 102 (2002): 44-47. -4. position of the american dietetic associa- tion: food and water safety, journal of the american dietetic association 103 (2003): 1203-1218. -5. centers for disease control and prevention, june 2006. -6. b. j. mccabe-sellers and s. e. beattie, food safety: emerging trends in foodborne illness surveillance and prevention, journal of the american dietetic association 104 (2004): 1709-1717. -7. j. b. anderson and coauthors, a camera s view of consumer food-handling behaviors, journal of the american dietetic association 104 (2004): 186-191. -8. u.s. food and drug administration, con- sumer asked questions about bse in prod- ucts regulated by fda s center for food safety and applied nutrtition (cfsan), www.cfsan.fda.gov/~comm/bsefaq.html, site updated september 14, 2005 and visited december 6, 2006; u.s. department of agriculture, bovine spongiform encephalopathy (bse) q & a s, www.aphis.usda.gov/lpa/issues/bse/bse_q&a. -html, site updated january 21, 2004 and visited december 6, 2006. -9. c. a. donnelly, bovine spongiform en- cephalopathy in the united states an epidemiologist s view, new england journal of medicine 350 (2004): 539-542; t. hampton, what now, mad cow? -experts put risk to us public in perspective, journal of the american medical association 291 (2004): 543-549. answers study questions (multiple choice) 10. e. t. ryan, m. e. wilson, and k. c. kain, illness after international travel, new eng- land journal of medicine 347 (2002): 505-516. -11. m. t. osterholm and a. p. norgan, the role of irradiation in food safety, new england journal of medicine 350 (2004): 1898-1901; d. w. thayer, irradiation of food helping to ensure food safety, new england journal of medicine 350 (2004): 1811-1812. -12. position of the american dietetic associa- tion: food irradiation, journal of the ameri- can dietetic association 100 (2000): 246-253. -13. p. frenzen and coauthors, consumer accep- tance of irradiated meat and poultry prod- ucts, www.cdc.gov/foodnet/pub/ publications. -14. r. w. miller, how environmental hazards in childhood have been discovered: carcio- gens, teratogens, neurotoxicants, and oth- ers, pediatrics 113 (2004): 945-951; r. sreedharan and d. i. mehta, gastrointesti- nal tract, pediatrics 113 (2004): 1044-1050; department of health and human services, third national report on human exposure to environmental chemicals, july 2005. -15. c. s. roegge and s. l. schantz, motor func- tion following developmental exposure to pcbs and/or mehg, neurotoxicology and teratology 28 (2006): 260-277. -16. centers for disease control and prevention, third national report on human exposure to environmental chemicals, july 2005. -17. epa fact sheet, update: national listing of fish and wildlife advisories, may 2002, available online at www.epa.gov/ost/fish. -18. p. w. davidson, g. j. myers, and b. weiss, mercury exposure and child development outcomes, pediatrics 113 (2004): 1023-1029. -19. institute of medicine, seafood choices: balancing benefits and risks, october 2006. -20. r. l. jones and coauthors, blood mercury levels in young children and childbearing- aged women united states, 1999-2002, morbidity and mortality weekly report 53 (2004): 1018-1020. -21. c. w. levenson and d. m. axelrad, too much of a good thing? -update on fish consumption and mercury exposure, nutri- tion reviews 64 (2006): 139-145. -22. b. weiss, s. amler, and r. w. amler, pesti- cides, pediatrics 113 (2004): 1030-1036. -23. b. p. baker and coauthors, pesticide residues in conventional, integrated pest manage- ment (ipm)-grown and organic foods: in- sights from three us data sets, food additives and contaminants 19 (2002): 427-446. -24. c. lu and coauthors, organic diets signifi- cantly lower children s dietary exposure to organophosphorus pesticides, environmental health perspectives 114 (2006): 260-263. -25. l. grinder-pedersen and coauthors, effect of diets based on foods from conventional versus organic production on intake and excretion of flavonoids and markers of antioxidative defense in humans, journal of agricultural and food chemistry 51 (2003): 5671-5676. -26. m. dinovi, the 2006 exposure assessment for acrylamide, july 2006, www.cfsan .fda.gov/~dms/acryexpo.html. -27. r. h. stadler and g. scholz, acrylamide: an update on current knowledge in analysis, levels in food, mechanisms of formation, and potential strategies of control, nutrition reviews 62 (2004): 449-467. -28. fda action plan for acrylamide in food, march 2004, www.cfsan.fda.gov/~dms/ acrypla3.html. -29. national academy of sciences, epa assess- ment of dioxin understates uncertainty about health risks and may overstate human cancer risk, 2006, available at http:// national-academies.org. -30. d. schardt, microwave myths: fact vs. fiction, nutrition action heathletter, april 2005, pp. -10-12. -31. national academy of sciences, health risks from dioxin and related compounds: evalua- tion of the epa reassessment, july 2006. -32. j. raloff, hormones: here s the beef, science news 161 (2002): 10-12. -33. d. h. hammer and c. j. gill, from the farm to the kitchen table: the negative impact of antimicrobial use in animals on humans, nutrition reviews 60 (2002): 261-264. -34. b. g. blackburn and coauthors, surveillance for waterborne-disease outbreaks associated with drinking water united states, 2001- 2002, morbidity and mortality weekly report 53 (2002): 23-45. -1. b 2. d 3. d 4. b 5. c 6. d 7. a 8. a 9. a 10. c highlight 19 highlight food biotechnology advances in food biotechnology promise just about everything from the frivolous (a tear-free onion) to the profound (a hunger- free world). -already biotechnology has pro- duced leaner meats, longer shelf lives, better nutrient composition, and greater crop yields grown with fewer pesticides. -overall, biotech- nology offers numerous opportunities to overcome food shortages, improve the environment, and elimi- nate disease.1 but it also raises concerns about possible risks to the environment and human health. -critics assert that biotechnology will exacerbate world hunger, destroy the environment, and en- danger health. -this highlight presents some of the many issues surrounding genetically engineered foods, and the accompany- ing glossary defines the terms used. -the promises of genetic engineering for centuries, farmers have been selectively breeding plants and animals to shape the characteristics of their crops and livestock. -they have created prettier flowers, hardier vegetables, and leaner animals. -consider the success of selectively breeding corn. -early farmers in mexico began with a wild, native plant called teosinte (tay-oh-seen-tay) that bears only five or six kernels on each small spike. -many years of patient selective breeding have produced large ears filled with hundreds of plump kernels aligned in perfect formation, row after row. -such genetic improvements, together with the use of irriga- tion, fertilizers, and pesticides, were responsible for more than half of the increases in u.s. crop yields in the 20th century. -farm- ers still use selective breeding, but now, in the 21st century, ad- vances in genetic engineering have brought rapid and dramatic changes to agriculture and food production. -although selective breeding works, it is slow and imprecise be- cause it involves mixing thousands of genes from two plants and g lossary y n o t t i d e o t o h p / n a m e e r f hoping for the best. -with genetic engineer- ing, scientists can improve crops (or live- stock) by introducing a copy of the specific gene needed to produce the desired trait. -figure h19-1 (p. 694) illustrates the differ- ence. -once introduced, the selected gene acts like any other gene it provides instruc- tions for making a protein. -the protein then determines a characteristic in the genetically modified plant or animal. -in short, the process is now faster and more refined. -farmers no longer need to wait patiently for breeding to yield im- proved crops and animals, nor must they even respect natural lines of reproduction among species. -laboratory scientists can now copy genes from any organism and insert them into almost any other organism plant, animal, or microbe. -their work is changing not only the way farmers plant, fertilize, and harvest their crops, but also the ways the food industry processes food and consumers receive nutrients, phytochemicals, and drugs. -this wild predecessor of corn, with its sparse five or six kernels, bears little resemblance to today s large, full, sweet ears. -r e n a t r o m o i n o t n a i r t s biotechnology: the use of to enhance crop production. -biological systems or organisms to create or modify products. -examples include the use of bacteria to make yogurt, yeast to make beer, and cross-breeding genetic engineering: the use of biotechnology to modify the genetic material of living cells so that they will produce new substances or perform new functions. -foods produced via this technology are called genetically modified (gm) or genetically engineered (ge) foods. -plant-pesticides: pesticides made by the plants themselves. -rennin: an enzyme that coagulates milk; found in the gastric juice of cows, but not human beings. -693 694 highlight 19 figure h19-1 selective breeding and genetic engineering compared traditional selective breeding traditional selective breeding combines many genes from two varieties of the same species to produce one with the desired characteristics. -donor commercial variety in the new variety, many genes have been transferred. -+ = desired gene desired gene genetic engineering through genetic engineering, a single gene (or several) are transferred from the same or different species to produce one with the desired characteristics. -donor commercial variety in the new variety, only the desired gene is transferred. -+ = desired gene isolated source: 1995 monsanto company desired gene extended shelf life among the first products of genetic engineering to hit the market were tomatoes that stay firm and ripe longer than regular toma- toes that are typically harvested green and ripened in the stores. -these genetically modified tomatoes promise less waste and higher profits. -normally, tomatoes produce a protein that softens them after they have been picked. -scientists can now introduce into a tomato plant a gene that is a mirror image of the one that codes for the softening enzyme. -this gene fastens itself to the rna of the native gene and blocks synthesis of the softening pro- tein. -without this protein, the genetically altered tomato softens more slowly than a regular tomato, allowing growers to harvest it at its most flavorful and nutritious vine-ripe stage. -improved nutrient composition genetic engineering can also improve the nutrient composition of foods.2 instead of manufacturers adding nutrients to foods dur- ing processing, plants can be genetically altered to do their own fortification work a strategy called biofortification.3 biofortifica- tion of staple crops with key vitamins and minerals can effectively combat the nutrient deficiency diseases that claim so many lives worldwide.4 soybeans may be implanted with a gene that upgrades s r a - a d s u , n i v r a g d i v a d f o y s e t r u o c o t o h p genetically modified cauliflower is orange, reflecting a change in a single gene that increases its production of beta-carotene 100-fold. -soy protein to a quality approaching that of milk. -corn may be modified to contain lysine and tryptophan, its two limiting amino acids. -soybean and canola plants can be genetically modified to alter the composition of their oils, making them richer in the heart-healthy monounsaturated fatty acids. -golden rice, which has received genes from a daffodil and a bacterium that enable it to make beta-carotene, offers some promise in helping to correct vitamin a deficiency worldwide. -(chapter 11 described how vita- min a deficiency contributes to the deaths of 2 million children and the blindness of a half million each year.) -of course, increas- ing nutrients in crops may have unintended consequences as well. -for example, when broccoli is manipulated to increase its se- lenium content, production of the cancer-fighting phytochemical sulforaphane declines.5 as you might predict, enhancing the chemical composition of plants is not limited to the essential nutrients. -genetically modified crops can also produce more of the phytochemicals that help maintain health and reduce the risks of chronic diseases (see high- light 13).6 they can also be coaxed to produce less phytate, which allows more zinc to be absorbed.7 the possibilities seem endless. -efficient food processing genetic engineering also helps to process foods more efficiently, which saves money. -for example, the protein rennin, which is used to coagulate milk in the production of cheese, has tradition- ally been harvested from the stomachs of calves, a costly process. -now scientists can insert a copy of the rennin gene into bacteria and then use bacterial cultures to mass-produce rennin saving time, money, space, and animals. -genetic engineering can also help to bypass costly food- processing steps. -at present, people who are lactose intolerant can buy milk that has been treated with the lactase enzyme. -wouldn t it be more convenient, and less expensive, if scientists could induce cows to make lactose-free milk directly? -they re working on it. -they have already successfully inserted into mice the genetic material needed to make lactase in their mammary glands, thereby producing low-lactose milk. -decaffeinated coffee beans are another real possibility. -efficient drug delivery genetic research today has progressed well beyond tweaking a gene here and there to produce a desired trait. -scientists can now clone animals. -by cloning animals, scientists have the ability to produce both needed food and pharmaceutical products. -using animals and other organisms in the development of pharmaceu- ticals is whimsically called biopharming. -for example, a cow cloned with the genetic equipment to make a vaccine in its milk could provide both nourishment and immunization to a whole village of people now left unprotected because they lack food and medical help. -similarly, researchers have figured out how to in- duce bananas and potatoes to make hepatitis vaccines and to- bacco leaves to make aids drugs. -they can also harvest vaccines by genetically altering hydroponically grown tomato plants to se- crete a protein through their root systems into the water. -using foods to deliver drugs is only a small part of the promise and po- tential biotechnology offers the field of medicine.8 genetically assisted agriculture genetic engineering has helped farmers to increase yields, extend growing seasons, and grow crops that resist herbicides. -about half of the soybean crops in the united states have been geneti- cally engineered to withstand a potent herbicide. -as a result, farmers can spray whole fields with this herbicide and kill the weeds without harming the soybeans. -similarly, farmers can grow crops that produce their own pes- ticides substances known as plant-pesticides. -corn, broccoli, and potatoes have received a gene from a bacterium that pro- duces a protein that is toxic to leaf-chewing caterpillars (but not to humans). -yellow squash has been given two viral genes that confer resistance to the most common viral diseases. -potatoes can now produce a beetle-killing toxin in their leaves. -these crops and many others like them are currently being grown or tested in fields around the united states. -growing crops that make their own pesticides allows farmers to save time, increase yields, and use fewer, or less harmful, pesticides.9 other possibilities many other biotechnology possibilities are envisioned for the near future. -shrimp may be empowered to fight diseases with genetic ammunition borrowed from sea urchins. -plants may be given spe- cial molecules to help them grow in polluted soil. -with these and other advances, farmers may reliably produce bumper crops of food every year on far fewer acres of land, with less loss of water and topsoil, and far less use of toxic pesticides and herbicides. -sup- porters of biotechnology predict that these efforts will enhance food production and help meet the challenge of feeding an ever- increasing world population. -they contend that genetically modi- fied crops have the potential to eliminate hunger and starvation. -others suggest that the problems of world hunger are more com- food biotechnology 695 plex than biotechnology alone can resolve and that the potential risks of genetic engineering may outweigh the potential benefits.10 the projects mentioned in this highlight are already in progress. -close on their heels are many more ingenious ideas. -what if salt tolerance could be transplanted from a coastal marsh plant into crop plants? -could crops then be irrigated with seawa- ter, thus conserving dwindling freshwater supplies? -would the world food supply increase if rice farmers could grow plants that were immune to disease? -what if consumers could dictate which traits scientists insert into food plants? -would they choose to add phytochemicals to fight cancer or reduce the risk of heart disease? -these and other possibilities seem unlimited, and though they may sound incredible, many such products have already been de- veloped and are awaiting approval from the fda, epa, and usda. -the potential problems and concerns although many scientists hail biotechnology with confidence, oth- ers have reservations. -some consumers also have concerns about what they call frankenfoods. -those who oppose biotechnology fear for the safety of a world where genetic tampering produces ef- fects that are not yet fully understood. -they suspect that the food industry may be driven by potential profits, without ethical consid- erations or laws to harness its effects. -they point out that even the scientists who developed the techniques cannot predict the ulti- mate outcomes of their discoveries. -these consumers don t want to eat a scientific experiment or interfere with natural systems. -ge- netic decisions, they say, are best left to the powers of nature. -if science and the marketplace are allowed to drive biotechnol- ogy without restraint, critics fear that these problems may result: t i d e o t o h p / n i e t s p e l e h c a r some consumers believe that food biotechnology will cause more harm than good. -696 highlight 19 disruption of natural ecosystems. -new, genetically unusual organisms that have no natural place in the food chain or evolutionary biological systems could escape into the envi- ronment and reproduce. -introduction of diseases. -newly created viruses may mutate to cause deadly diseases that may attack plants, animals, or human beings. -genetically modified bacteria may develop resistance to antibiotics, making the drugs useless in fight- ing infections. -introduction of allergens and toxins. -genetically modified crops may contain new substances that have conse- quences, such as causing allergies.11 creation of biological weapons. -fatal bacterial and viral dis- eases may be developed for use as weapons. -ethical dilemmas. -critics pose the question, how many hu- man genes does an organism have to contain before it is considered human? -for instance, how many human genes would a green pepper have to contain before one would have qualms about eating it? -12 proponents of biotechnology respond that evidence to date does not justify these concerns.13 opponents counter that the lack of evidence showing harm does not provide evidence showing safety. -these opposing views illustrate the tension between the forward thrust of science and the hesitation of consumers. -both positions highlight the need for more research on the safety and effectiveness of genetically modified food. -table h19-1 summa- rizes the issues. -from another perspective, some argue that the concerns ex- pressed by those protesting genetically engineered foods reflect prejudices acquired in an elitist world of fertile land and abundant food. -those living in poverty-stricken areas of the world do not have the luxury of determining how to grow crops and process foods. -they cannot afford the delays created when protesters de- stroy test crops and disrupt scientific meetings. -they need solu- tions now. -people are starving, and genetic engineering holds great promise for providing them with food. -at a minimum, critics of biotechnology have made a strong case for rigorous safety testing and labeling of new products. -they contend, for example, that when a new gene has been introduced into a food, tests should ensure that other, unwanted genes have not accompanied it. -if a disease-producing microorganism has do- nated genetic material, scientists must prove that no dangerous characteristic from the microorganism has also entered the food. -if the inserted genetic material comes from a source to which some people develop allergies, such as nuts, then the new product should be labeled to alert them. -furthermore, if the newly altered genetic material creates proteins that have never before been en- countered by the human body, their effects should be studied to ensure that people can eat them safely. -fda regulations the fda has taken the position that foods produced through biotechnology and cloning are not substantially different from others and require no special testing, regulations, or labeling. -af- ter all, most foods available today have already been genetically altered by years of selective breeding. -the new vegetable broc- coflower, a product of sophisticated cross-breeding of broccoli with cauliflower, met no testing or approval barriers on its way to the dinner plate. -when the vegetable became available on the market, scientists studied its nutrient contents (see appendix h), but they did not question its safety. -in most cases, the new genetically modified food differs from the old conventional one only by a gene or two.14 the rennin pro- duced by bacteria is structurally and functionally the same as the rennin produced by calves, for example. -for that reason, the fda considers it and other genetically engineered foods generally recognized as safe (gras). -15 a product such as the tomato described earlier need not be tested because its new genes prevent synthesis of a protein and add nothing but a tiny fragment of genetic material. -nor does this tomato require special labeling because it is not significantly different from the many other varieties of tomatoes on the mar- ket. -on the other hand, any substances introduced into a food (such as a hormone or protein) by way of bioengineering must meet the same safety standards applied to all additives. -a tomato plant with a gene that, for example, produces a pesticide cannot be marketed until tests prove it safe for consumption. -the fda as- sures consumers that all bioengineered foods on the market to- day are as safe as their traditional counterparts. -foods produced through biotechnology that are substantially different from others must be labeled to identify that difference. -for example, if the nutrient composition of the new product dif- fers from its traditional counterpart, as in the soybean and canola oils mentioned earlier, then labeling is required. -similarly, if an al- lergy-causing protein has been introduced to a nonallergenic food, then labeling must warn consumers. -most consumers want all genetically altered products clearly labeled. -consumer advocacy groups claim that by not requiring such labeling, the fda forces millions of consumers to be guinea pigs, unwittingly testing genetically modified foods. -additionally, they say, people who have religious objections to consuming foods to which genes of prohibited organisms have been added have no way of identifying those foods. -for example, someone keeping a kosher kitchen may unknowingly use a food containing genes from a pig. -currently, labeling is voluntary. -manufacturers may state that a product has been genetically engineered. -those who do would be wise to explain its purpose and benefit. -when consumers recognize a personal health benefit, most tend to accept genetically engineered foods.16 speaking in defense of the fda s position are the fda itself, recognized as the nation s leading expert and advocate for food safety, and the american dietetic association, which represents current scientific thinking in nutrition.17 many other scientific or- ganizations agree, contending that biotechnology can deliver an improved food supply if we give it a fair chance to do so. -will our impressive new technologies provide foods to meet the needs of the future? -some would say yes. -biotechnology holds a world of promise, and with proper safeguards and controls, it may yield products that meet the needs of consumers almost perfectly. -food biotechnology 697 table h19-1 food biotechnology: point, counterpoint arguments in opposition to genetic engineering arguments in support of genetic engineering 1. ethical and moral issues. -it s immoral to play god by mixing genes from organisms unable to do so naturally. -religious and vegetarian groups object to genes from prohibited species occurring in their allow- able foods. -2. imperfect technology. -the technology is young and imperfect genes rarely function in just one way, their placement is imprecise ( shotgun ), and all of their potential effects are impossible to predict. -toxins are as likely to be produced as the desired trait. -over 95 percent of dna is called junk because scientists have not yet determined its function. -3. environmental concerns. -environmental side effects are unknown. -the power of a genetically modified organism to change the world s envi- ronments is unknown until such changes actually occur then the genie is out of the bottle. -once out, insects, birds, and the wind dis- tribute genetically altered seed and pollen to points unknown. -4. genetic pollution. -other kinds of pollution can often be cleaned up with money, time, and effort. -once genes are spliced into living things, those genes forever bear the imprint of human tampering. -5. crop vulnerability. -pests and disease can quickly adapt to overtake genetically identical plants or animals around the world. -diversity is key to defense. -6. loss of gene pool. -loss of genetic diversity threatens to deplete valu- able gene banks from which scientists can develop new agricultural crops. -7. profit motive. -genetic engineering will profit industry more than the world s poor and hungry. -8. unproven safety for people. -human safety testing of genetically altered products is generally lacking. -the population is an unwitting experimental group in a nationwide laboratory study for the benefit of industry. -9. increased allergens. -allergens can unwittingly be transferred into foods. -1. ethical and moral issues. -scientists throughout history have been perse- cuted and even put to death by fearful people who accuse them of playing god. -yet, today many of the world s citizens enjoy a long and healthy life of comfort and convenience due to once-feared scientific advances put to practical use. -2. advanced technology. -recombinant dna technology is precise and reli- able. -many of the most exciting recent advances in medicine, agriculture, and technology were made possible by the application of this technology. -3. environmental protection. -genetic engineering may be the only hope of saving rain forest and other habitats from destruction. -through genetic engineering, farmers can make use of previously unproductive lands such as salt-rich soils and arid areas. -4. genetic improvements. -genetic side effects are more likely to benefit the environment than to harm it. -5. improved crop resistance. -pests and diseases can be specifically fought on a case-by-case basis. -biotechnology is the key to defense. -6. gene pool preserved. -thanks to advances in genetics, laboratories around the world are able to stockpile the genetic material of millions of species that, without such advances, would have been lost forever. -7. everyone profits. -industries benefit from genetic engineering, and a thriv- ing food industry benefits the nation and its people, as witnessed by coun- tries lacking such industries. -genetic engineering promises to provide ade- quate nutritious food for millions who lack such food today. -developed nations gain cheaper, more attractive, more delicious foods with greater variety and availability year round. -8. safe for people. -human safety testing of genetically altered products is unneeded because the products are essentially the same as the original foodstuffs. -9. control of allergens. -a few allergens can be transferred into foods, but these are known. -also, foods likely to contain them are clearly labeled to warn consumers. -10. decreased nutrients. -a fresh-looking tomato or other produce held for 10. increased nutrients. -genetic modifications can easily enhance the nutri- several weeks may have lost substantial nutrients. -ents in foods. -11. no product tracking. -without labeling, the food industry cannot track problems to the source. -12. overuse of herbicides. -farmers, knowing that their crops resist herbi- cide effects, will use them liberally. -13. increased consumption of pesticides. -when a pesticide is produced by the flesh of produce, consumers cannot wash it off the skin of the pro- duce with running water as they can with ordinary sprays. -14. lack of oversight. -government oversight is run by industry people for the benefit of industry no one is watching out for the consumer. -11. excellent product tracking. -the identity and location of genetically altered foodstuffs are known, and they can be tracked should problems arise. -12. conservative use of herbicides. -farmers will not waste expensive herbi- cides in second or third applications when the prescribed amount gets the job done the first time. -13. reduced pesticides on foods. -pesticides produced by produce in tiny amounts known to be safe for consumption are more predictable than applications by agricultural workers who make mistakes. -because other genetic manipulations will eliminate the need for postharvest spraying, fewer pesticides will reach the dinner table. -14. sufficient regulation and rapid response. -government agencies are effi- cient in identifying and correcting problems as they occur in the industry. -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 19, then to highlights nutrition on the net. -search for biotechnology on the usda site: www.usda.gov get a pro biotechnology perspective from the council for biotechnology information: www.whybiotech.com for another for view, search for biotechnology at the international food information council: www.ific.org get a con biotechnology perspective from the genetic engineering section of greenpeace, usa: www.greenpeaceusa.org another against view is available from the union of concerned scientists: www.ucsusa.org 698 highlight 19 references 1. p. w. phillips, biotechnology in the global agri-food system, trends in biotechnology 20 (2002): 376 381. -2. l. yan and p. s. kerr, genetically engineered crops: their potential use for improvement of human nutrition, nutrition reviews 60 (2002): 135 141. -3. r. m. welch, biotechnology, biofortifica- tion, and global health, food and nutrition bulletin 26 (2005): 419 421; h. e. bouis, plant breeding: a new tool for fighting micronutrient malnutrition, journal of nutrition 132 (2002): 491s 494s. -4. g. h. lyons and coauthors, exploiting micronutrient interaction to optimize biofortification programs: the case for inclusion of selenium and iodine in the harvestplus program, nutrition reviews 62 (2004): 247 252. -5. j. w. finley, selenium accumulation in plant foods, nutrition reviews 63 (2005): 196 202. -6. m. a. grusak, phytochemicals in plants: genomics-assisted plant improvement for nutritional and health benefits, current opinion in biotechnology 13 (2002): 508 511. -7. k. m. hambridge and coauthors, zinc absorption from low-phytate hybrids of maize and their wild-type isohybrids, ameri- can journal of clinical nutrition 79 (2004): 1053 1059. -8. p. b. fontanarosa and c. d. deangelis, medical applications of biotechnology, journal of the american medical association 293 (2005): 866 867. -9. j. huang, c. pray, and s. rozelle, enhancing the crops to feed the poor, nature 418 (2002): 678 684. -10. a. bakshi, potential adverse health effects of genetically modified crops, journal of toxi- cology and environmental health. -part b, critical reviews 6 (2003): 211 215. -11. h. v. davies, gm organisms and the eu regulatory environment: allergenicity as a risk component, proceedings of the nutrition society 64 (2005): 481 486; r. mazza and coauthors, assessing the transfer of geneti- cally modified dna from feed to animal tissues, transgenic research 14 (2005): 775 784. -12. r. epstein, redesigning the world: ethical questions about genetic engineering, an essay available at online.sfsu.edu/ ~rone/ge%20essays/redesigning.htm. -13. j. a. thomas, safety of foods derived from genetically modified plants, texas medicine 99 (2003): 66 69. -14. k. t. atherton, safety assessment of geneti- cally modified crops, toxicology 181 (2002): 421 426. -15. d. l. pelletier, science, law, and politics in the food and drug administration s geneti- cally engineered foods policy: fda s 1992 policy statement, nutrition reviews 63 (2005): 171 181. -16. j. l. brown and y. ping, consumer percep- tion of risk associated with eating geneti- cally engineered soybeans is less in the presence of a perceived consumer benefit, journal of the american dietetic association 103 (2003): 208 214. -17. position of the american dietetic associa- tion: agricultural and food biotechnology, journal of the american dietetic association 106 (2006): 285 293. this page intentionally left blank jim scherer/getty images nutrition in your life throughout this chapter, the thomsonnow logo indicates an opportunity for online self-study, linking you to interactive tutorials and videos based on your level of understanding. -www.thomsonedu.com/thomsonnow imagine living with hunger from the moment you wake up until the time you thankfully fall asleep and all through your dreams as well. -meal after meal, day after day, you have little or no food to eat. -you know you need food, but nutrition portfolio journal you have no money. -would you beg on the street corner or go dumpster diving at the nearest fast-food restaurant? -and then where would you find your next meal? -how will you ever get enough to eat as long as you live in poverty? -resolving the hunger problem whether in your community or on the other side of the world depends on alleviating poverty and using resources wisely. -hunger and the global environment worldwide, one person in every eight experiences persistent hunger not the healthy appetite triggered by anticipation of a hearty meal, but the painful sensation caused by a lack of food. -in this chapter, hunger takes on the greater meaning hunger that develops from prolonged, recurrent, and involuntary lack of food and results in discomfort, illness, weakness, or pain that exceeds the usual uneasy sensation. -such hunger deprives a person of the physical and mental energy needed to enjoy a full life and of- ten leads to severe malnutrition and death. -tens of thousands of people die of starvation each day one child every five seconds.1 the enormity of the world hunger problem is reflected not only by huge numbers, but also by major challenges. -as people populate and pollute the earth, resources become depleted, making food less available. -hunger and poverty, population growth, and environmental degradation are linked to- gether; thus they tend to worsen each other. -because their causes overlap, so do their solutions: any initiative a person takes to help solve one prob- lem will help solve many others. -eliminating hunger requires a balance among the distribution of food, the numbers of people, and the care of the environment. -resolving the hunger problem may seem at first beyond the influence of the ordinary person. -can one person s choice to limit family size or to recy- cle a bottle or to volunteer at a food recovery program make a difference? -in truth, such choices produce several benefits. -for one, a person s action may influence many other people over time. -for another, a repeated ac- tion becomes a habit, with compounded benefits. -for still another, making choices with an awareness of the consequences gives a person a sense of personal control, hope, and effectiveness. -the daily actions of many con- cerned people can help solve the problems of hunger in their own neigh- borhoods or on the other side of the world. -c h a p t e r 20 chapter outline hunger in the united states defining hunger in the united states relieving hunger in the united states world hunger food shortages malnutrition diminishing food supply poverty and overpopulation environmental degradation and hunger environmental limitations in food production other limitations in food production solutions sustainable development worldwide activism and simpler lifestyles at home highlight 20 progress toward sustain- able food production never doubt that a small group of thoughtful, committed people can change the world. -indeed, it is the only thing that ever has. -margaret mead hunger: consequence of food insecurity that, because of prolonged, involuntary lack of food, results in discomfort, illness, weakness, or pain that goes beyond the usual uneasy sensation. -701 702 chapter 20 food security categories: high food security: no indications of food-access problems or limitations marginal food security: one or two indica- tions of food-access problems but with little or no change in food intake an estimated one out of six children lives in poverty. -food insecurity categories: low food security: reduced quantity of diet with little or no indication of reduced food intake; formerly known as food inse- curity without hunger very low food security: multiple indications of disrupted eating patterns and reduced food intake; formerly known as food inse- curity with hunger prevalence of food figure 20-1 insecurity and hunger in u.s. households, 2005 food secure very low food security low food security source: economic research service, u.s. department of agricul- ture, www.ers.usda.gov/publications/, posted november 2006 and visited on december 7, 2006. food security: access to enough food to sustain a healthy and active life. -food insecurity: limited or uncertain access to foods of sufficient quality or quantity to sustain a healthy and active life. -food insufficiency: an inadequate amount of food due to a lack of resources. -food poverty: hunger resulting from inadequate access to available food for various reasons, including inadequate resources, political obstacles, social disruptions, poor weather conditions, and lack of transportation. -hunger in the united states ideally, all people at all times would have access to enough food to support an ac- tive, healthy life. -in other words, they would experience food security. -unfortu- nately, more than 35 million people in the united states, including 12 million children, live in poverty and cannot afford to buy enough food to maintain good health.2 said another way, one out of nine households experiences hunger or the threat of hunger. -given the agricultural bounty and enormous wealth in this coun- try, do these numbers surprise you? -the limited or uncertain availability of nutri- tionally adequate and safe foods is known as food insecurity and is a major social problem in our nation today. -inadequate diets lead to poor health in adults and impaired physical, psychological, and cognitive development in children. -the accompanying how to presents the questions used in national surveys to identify food insecurity in the united states, and figure 20-1 shows the most recent findings. -responses to these questions provide crude, but necessary, data to esti- mate the degree of hunger in this country.3 defining hunger in the united states at its most extreme, people experience hunger because they have absolutely no food. -more often, they have too little food (food insufficiency) and try to stretch their limited resources by eating small meals or skipping meals often for days at a time. -sometimes hungry people obtain enough food to satisfy their hunger, perhaps by seeking food assistance or finding food through socially unacceptable ways begging from strangers, stealing from markets, or scavenging through garbage cans, for example. -sometimes obtaining food raises concerns for food safety for ex- ample, when rot, slime, mold, or insects have damaged foods or when people eat others leftovers or meat from roadkill.4 hunger has many causes, but in developed countries, the primary cause is food poverty. -people are hungry not because there is no food nearby to purchase, but be- cause they lack money. -an estimated one out of eight people in the united states lives in poverty. -even those above the poverty line may not have food security. -phys- ical and mental illnesses and disabilities, unemployment, low-paying jobs, unex- pected or ongoing medical expenses, and high living expenses threaten their financial stability. -when money is tight, people are forced to choose between food and life s other necessities utilities, housing, and medical care. -food costs are more variable and flexible; people can purchase fewer groceries to lower the monthly food bill, but they usually can t pay only a portion of the bills for electricity, rent, or med- ication. -other problems further contribute to food poverty, such as abuse of alcohol and other drugs; lack of awareness of available food assistance programs; and the reluctance of people, particularly the elderly, to accept what they perceive as wel- fare or charity. -lack of resources remains the major cause of food poverty in de- veloped countries, and solving this problem would do a lot to relieve hunger. -in the united states, poverty and hunger reach across various segments of soci- ety, touching single parents living in households with their children; hispanics and african americans; and those living in the inner cities more than others. -people liv- ing in poverty are simply unable to buy sufficient amounts of nourishing foods, even if they are wise shoppers. -for many of the children in these families, school lunch (and breakfast, where available) may be the only nourishment for the day. -otherwise they go hungry, waiting for an adult to find money for food. -not surpris- ingly, these children are more likely to have health problems than those who eat regularly.5 they also tend to perform poorly in school and in social situations.6 ironically, hunger and obesity exist side by side in the united states sometimes within the same person. -that hunger reflects an inadequate food intake and obe- sity implies an excessive intake seems paradoxical, but research studies have con- firmed the relationship.7 the highest rates of obesity occur among those living in the greatest poverty the same people who live with food insecurity.8 unfortu- hunger and the global environment 703 how to identify food insecurity in a u.s. household to determine the extent of food insecurity in a household, surveys ask questions about behaviors and conditions known to charac- terize households having difficulty meeting basic food needs during the past 12 months. -most often, adults tend to protect their children from hunger. -in the most severe cases, children also suffer from hunger and eat less. -1. did you worry whether food would run out before you got money to buy more? -2. did you find that the food you bought just didn t last and you didn t have money to buy more? -8. did you ever lose weight because you didn t have enough money to buy food? -9. did you or other adults in your household ever not eat for a whole day because you were running out of money to buy food? -10. did this happen in 3 or more months during the previous year? -11. did you rely on only a few kinds of low- cost food to feed your children because you were running out of money to buy food? -12. were you unable to feed your children a balanced meal because you couldn t afford it? -3. were you unable to afford to eat balanced 13. were your children not eating enough meals? -4. did you or other adults in your household ever cut the size of your meals or skip meals because there wasn t enough food? -5. did this happen in 3 or more months during the previous year? -6. did you ever eat less than you felt you should because there wasn t enough money for food? -7. were you ever hungry but didn t eat be- cause you couldn t afford enough food? -because you just couldn t afford enough food? -14. did you ever cut the size of your chil- dren s meals because there wasn t enough money for food? -15. were your children ever hungry but you just couldn t afford enough food? -18. did your children ever not eat for a whole day because there wasn t enough money for food? -the more positive responses, the greater the food insecurity. -households with chil- dren answer all of the questions and are categorized as follows: (cid:2)2 positive responses (cid:3) food secure 3 7 positive responses (cid:3) low food security (cid:4)8 positive responses (cid:3) very low food security households without children answer the first 10 questions and are categorized as follows: (cid:2)2 positive responses (cid:3) food secure 3 5 positive responses (cid:3) low food (cid:4)6 positive responses (cid:3) very low food security security 16. did your children ever skip a meal because there wasn t enough money for food? -figure 20-1 (on p. 702) shows the results of the 2005 surveys. -17. did this happen in 3 or more months during the previous year? -source: united states department of agriculture, household food security in the united states, 2005, available at www.ers.usda.gov/publications/err29. -nately, many healthful food choices cost more than the energy-dense foods that foster weight gain but offer few, if any, nutrients.9 foods such as doughnuts, pizzas, and hamburgers provide the most energy and satiety for the least cost. -further- more, people who are unsure about their next meal are likely to overeat when food or money are available. -interestingly, food insecure people who do not participate in food assistance programs have a greater risk of obesity than those who do par- ticipate illustrating that providing food actually helps to prevent obesity.10 relieving hunger in the united states the american dietetic association (ada) calls for aggressive action to bring an end to domestic food insecurity and hunger and to achieve food and nutrition security for everybody living in the united states.11 many federal and local programs aim to prevent or relieve malnutrition and hunger in the united states. -federal food assistance programs adequate nutrition and food security are es- sential in supporting good health and achieving the public health goals of the united states. -to that end, an extensive network of federal assistance programs provides life- giving food to millions of u.s. citizens daily. -one out of every six americans receives food assistance of some kind, at a total cost of more than $40 billion per year. -even so, the programs are not fully successful in preventing hunger, but they do seem to improve the nutrient intakes of those who participate. -programs described in earlier chapters include the wic program for low-income pregnant women, breastfeeding mothers, and their young children (chapter 15); the school lunch, breakfast, and child-care food programs for children (chapter 16); and the food assistance programs for older adults such as congregate meals and meals on wheels (chapter 17). -the food stamp program, administered by the u.s. department of agriculture (usda), is the largest of the federal food assistance programs, both in amount of s e g a m i y t t e g / e l y o b m t i feeding the hungry in the united states. -704 chapter 20 four common methods of food recovery are: field gleaning: collecting crops from fields that either have already been harvested or are not profitable to harvest perishable food rescue or salvage: collecting perishable produce from wholesalers and markets prepared food rescue: collecting prepared foods from commercial kitchens nonperishable food collection: collecting processed foods from wholesalers and markets food recovery: collecting wholesome food for distribution to low-income people who are hungry. -food pantries: programs that provide groceries to be prepared and eaten at home. -emergency shelters: facilities that are used to provide temporary housing. -soup kitchens: programs that provide prepared meals to be eaten on site. -food bank: a facility that collects and distributes food donations to authorized organizations feeding the hungry. -money spent and in number of people served. -it provides assistance to almost 24 mil- lion people at a cost of more than $25 billion per year; more than half of the recipients are children.12 the usda issues debit cards through state agencies to households people who buy and prepare food together. -the amount a household receives depends on its size, resources, and income. -the average monthly benefit is about $86 per per- son.13 recipients may use the cards to purchase food and food-bearing plants and seeds, but not to buy tobacco, cleaning items, alcohol, or other nonfood items. -the ac- companying how to offers shopping tips for those on a limited budget. -the food stamp program improves nutrient intakes significantly, but hunger continues to plague the united states. -of the estimated 2 million homeless people in the united states who are eligible for food assistance, only 15 percent of single adults and 50 percent of families receive food stamps. -for some, reading, under- standing, and completing the application can be difficult. -for others, having to show identification and proof of homelessness can be frustrating. -for many, ac- cepting hunger is simply easier than meeting these challenges. -national food recovery programs efforts to resolve the problem of hunger in the united states do not depend solely on federal assistance programs. -national food recovery programs have made a dramatic difference. -the largest program, second harvest, coordinates the efforts of more than 40,000 food pantries, emer- gency shelters, and soup kitchens that feed more than 25 million people a year. -each year, an estimated one-fifth of our food supply is wasted in fields, commer- cial kitchens, grocery stores, and restaurants that s enough food to feed 49 million people. -food recovery programs collect and distribute good food that would other- wise go to waste. -volunteers might pick corn left in an already harvested field, a grocer might deliver ripe bananas to a local food bank, and a caterer might take leftover chicken salad to a community shelter, for example. -all of these efforts help to feed the hungry in the united states. -community efforts food recovery programs depend on volunteers. -concerned citizens work through local agencies and churches to feed the hungry. -community- based food pantries provide groceries, and soup kitchens serve prepared meals. -meals often deliver adequate nourishment, but most homeless people receive fewer than one and a half meals a day, so many are still inadequately nourished. -a com- bination of various strategies helps to build food security in a community.14 how to plan healthy, thrifty meals chapter 2 introduced the usda mypyramid food guide and principles for planning a healthy diet. -meeting that goal on a limited budget adds to the challenge. -to save money and spend wisely, plan and shop for healthy meals with the following tips in mind: planning make a grocery list before going to the store to avoid expensive impulse items. -do not shop when hungry. -use leftovers. -cook large quantities when time and money allow. -check for sales and clip coupons for products you need; plan meals to take advantage of sale items. -shopping buy day-old bread and other products from the bakery outlet. -select whole foods instead of convenience foods (potatoes instead of instant mashed potatoes, for example). -center meals on rice, noodles, and other try store brands. -grains. -use small quantities of meat, poultry, fish, or eggs. -use legumes instead of meat, poultry, fish, or eggs several times a week. -use cooked cereals such as oatmeal instead of ready-to-eat breakfast cereals. -buy fresh produce that is in season; buy canned or frozen items at other times. -buy only the amount of fresh foods that you will eat before it spoils. -buy large bags of frozen items or dry goods; when cooking, take out the amount needed and store the remainder. -buy fat-free dry milk; mix and refrigerate quantities needed for a day or two. -buy fresh milk by the gallon or half-gallon. -buy less expensive cuts of meat. -chuck and bottom round roast are usually inexpensive; cover during cooking and cook long enough to make meat tender. -buy whole chickens instead of pieces. -compare the unit price (cost per ounce, for example) of similar foods so that you can select the least expensive brand or size. -buy nonfood items such as toilet paper and laundry detergent at discount stores instead of grocery stores. -for daily menus and recipes for healthy, thrifty meals, visit the usda center for nutrition policy and promotion: www.usda.gov/cnpp hunger and the global environment 705 in summary food insecurity and hunger are widespread in the united states among those liv- ing in poverty. -ironically, hunger and poverty are common among obese peo- ple. -government assistance programs help to relieve poverty and hunger, but food recovery programs and other community efforts are equally important. -world hunger as distressing as hunger is in the united states, its prevalence is greater and its con- sequences more severe in developing countries. -although the hunger in these coun- tries has diverse causes, once again, the primary cause is poverty, and the poverty is more extreme than in the united states. -most people cannot grasp the severity of poverty in the developing world. -one-sixth of the world s 6.55 billion people have no land and no possessions at all. -they are the poorest poor. -they survive on less than $1 a day each, they lack clean drinking water, and they cannot read or write. -the average u.s. housecat receives twice as much protein every day as one of these people, and the cost of keeping that cat is greater than such a person s annual income. -the poorest poor are usually female. -many societies around the world under- value females, providing girls with poorer diets and fewer opportunities than boys. -malnourished girls become malnourished mothers who give birth to low- birthweight infants and the cycle of hunger, malnutrition, and poverty continues. -not only does poverty cause hunger, but tragically, hunger worsens poverty by robbing a person of the good health and the physical and mental energy needed to be active and productive. -hungry people simply cannot work hard enough to get themselves out of poverty. -malnourished people with a low bmi earn less money performing manual labor; an increase in bmi of 1 percent correlates with an in- crease in wages of 2 percent. -economists calculate that cutting world hunger and malnutrition in half by 2015 would generate a value of more than $120 billion in longer, healthier, and more productive lives.15 s e g a m i y t t e g / m a h a r g m i t food shortages world hunger brings to mind victims of famine, a severe food shortage in an area that causes widespread starvation and death. -in recent years, the natural causes of famine drought, flood, and pests have become less important than the political causes created by people. -figure 20-2 shows the hunger hotspots in the world. -political turbulence a sudden increase in food prices, a drop in workers in- comes, or a change in government policy can quickly leave millions hungry. -an estimated 30 million people died during the chinese famine of 1959 through 1961, the worst famine of the 20th century. -the main cause was government poli- cies associated with the great leap forward, a government initiative that was in- tended to transform china s economy. -however, the poorly planned communal farm system and the widespread waste of resources devastated the chinese agri- cultural system. -armed conflicts in the past decade, armed conflict and political unrest were the dominant cause of famine worldwide. -in times of war, farmers become war- riors, their agricultural fields become battlegrounds, the citizens go hungry, and the warring factions often block famine relief. -the world continues to struggle to find a middle ground between respecting the sovereignty of nations and insisting that all nations allow humanitarian assistance to reach the people. -when sup- plementary food programs reach the people in war-torn countries, the children benefit.16 feeding the hungry in calcutta, india. -famine: widespread and extreme scarcity of food in an area that causes starvation and death in a large portion of the population. -706 chapter 20 figure 20-2 hunger hotspots hunger is prevalent in the developing world, with some countries reporting hunger and malnutrition in over one-third of their population. -key: % of population undernourished no data 2.5% 2.5-4% 5-19% 20-34% 35% source: food and agriculture organization of the united nations, the state of food insecurity in the world 2003 available from www.wfp.org/country_brief/hunger_map/map/hungermap_popup/map_popup.html natural disasters natural disasters and other poor weather conditions create food shortages. -in 2004, the drought and desert locust infestation in north and west africa and the earthquake tsunami in indonesia dramatically reduced food sup- plies.17 during such natural disasters, food aid from countries around the world has provided a safety net for countries in need. -but food aid now does more than just off- set poor harvests and destroyed crops; it also delivers food relief to countries, such as ethiopia, that are chronically short of food because of ongoing drought and poverty. -s e g a m i y t t e g / s o r d n o h s i r h c malnutrition although we usually associate world hunger with famine, the numbers affected by famine are relatively small compared with those suffering from persistent hunger and malnutrition. -more than 850 million people, mostly women and children, are hungry and malnourished, with another 2 billion perilously close.18 the nutrients most likely to be lacking are iron, iodine, and vitamin a.19 the prevalence and con- sequences of these deficiencies stagger the mind.20 more than 30 percent of the world s population have iron-deficiency anemia, a leading cause of maternal deaths, premature births, low birthweights, infections, and premature deaths. -io- dine deficiency affects one out of seven, resulting in stillbirths and irreversible men- tal retardation (cretinism) in 37 million newborns every year. -almost 80 million young children (under age five) suffer from symptoms of vitamin a deficiency blindness, growth retardation, and poor resistance to common childhood infections such as measles. -the deficiency symptoms of these nutrients and those of the other vitamins and minerals were presented in chapters 10 through 13; chapter 6 described protein-energy malnutrition; and chapters 15 through 17 examined the effects of malnutrition during various stages of the life cycle. -the consequences of international efforts help to relieve hunger and poverty in afghanistan and around the world. -to help prevent blindness and reduce measles mortality, health care workers dis- tribute vitamin a supplements to millions of children worldwide. -hunger and the global environment 707 nutrient deficiencies are felt not only by individuals, but by entire nations. -when people suffer from mental retardation, growth failure, blindness, infections, and other consequences of malnutrition, the economy of their country declines as pro- ductivity decreases and health care costs increase. -the dramatic signs of malnutri- tion are most evident at each end of the life span in a nation s high infant mortality rate and low life expectancy. -in addition to specific nutrient deficiencies, one child in six worldwide is born underweight, and one in four children are underweight by the age of five. -these underweight children are malnourished and readily develop the diseases of poverty: parasitic and infectious diseases that cause diarrhea (dysentery and cholera), acute respiratory illnesses (pneumonia and whooping cough), measles, and malaria. -the synergistic combination of infectious disease and malnutrition dramatically increases the likelihood of early death.21 compared with adequately nourished children, the risk of death is 2.5 times greater for children with mild mal- nutrition, 4.6 times greater for children with moderate malnutrition, and 8.4 times greater for children with severe malnutrition. -each year, 5.6 million children die as a result of hunger and malnutrition. -most of them do not starve to death they die from the diarrhea and dehydration that accompany infections. -health care work- ers around the world save millions of lives each year by effectively reversing de- hydration and correcting the diarrhea with oral rehydration therapy (ort). -diminishing food supply most disturbingly, such misery and starvation exist side by side with ample food supplies. -technological advances in farming have increased crop yields. -and prices of many foods have fallen in response. -but the demand for food is great. -at the pres- ent rate of growth, the world s population may soon outstrip the rate of food produc- tion. -environmental degradation and dwindling water supplies may limit further growth in the world s food production in many agricultural areas. -no part of the world is safely insulated against future food shortages. -developed countries may be the last to feel the effects, but they will ultimately go as the world goes. -in summary natural causes such as drought, flood, and pests and political causes such as armed conflicts and government policies all contribute to the extreme hunger and poverty seen in the developing countries. -to meet future demands for food, tech- nology must improve food production, and nations must control overpopulation. -more than half of the world s underweight children live in just three countries: bangladesh india pakistan to prevent death from diarrheal disease, provide: adequate sanitation safe water oral rehydration therapy poverty and overpopulation the world s population is rising at an alarming rate, as figure 20-3 (p. 708) shows. -skyrocketing numbers threaten the earth s capacity to provide safe water and ad- equate food for its inhabitants. -the sheer magnitude of the world s annual population increase of more than 70 million people is difficult to comprehend. -every half-second, the population in- creases by another person. -every 40 days, the world adds the equivalent of another new york city. -during the six months of the terrible 1992 famine in somalia, an es- timated 300,000 people starved to death. -yet it took the world only 29 hours to re- place their numbers! -as the world s population continues to grow, much of the increase is occurring in developing countries where hunger and malnutrition are already widespread. -more people sharing the little food available can only worsen the problem. -stabi- lizing the population may be the only way the world s food production will be able the maximum number of people the earth can support over time is its human carry- ing capacity. -oral rehydration therapy (ort): the administration of a simple solution of sugar, salt, and water, taken by mouth, to treat dehydration caused by diarrhea. -a simple ort recipe: 1 c boiling water 2 tsp sugar a pinch of salt 708 chapter 20 figure 20-3 world population n o i l l i b 10 9 8 7 6 5 4 3 2 1 0 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050 mid-decade totals and projections to keep up with demands. -without population stabilization, the world can neither support the lives of people already born nor halt environmental deterioration around the globe. -and before the population problem can be resolved, it may be necessary to remedy the poverty problem. -in countries around the world, economic growth has been accompanied by slowed population growth. -population growth is a central factor contributing to poverty and hunger. -the reverse is also true: poverty and hunger contribute to population growth. -population growth leads to hunger and poverty the first of these cause- and-effect relationships is easy to understand. -as a population grows larger, more mouths must be fed, and the worse poverty and hunger become. -population growth also contributes to hunger indirectly by preempting good agricultural land for growing cities and industry and forcing people onto marginal land, where they cannot produce sufficient food for themselves. -the world s poorest people live in the world s most damaged and inhospitable environments. -hunger and poverty lead to population growth how does poverty lead to overpopulation? -poverty and its consequences inadequate food and shelter leave women vulnerable to physical abuse, forced marriages, and prostitution. -further- more, they lack access to reproductive health care and family planning counseling. -also, in some regions of the world, families depend on children to farm the land, haul water, and care for adults in their old age. -children are an economic asset for these families. -poverty claims many young children, who are among the most likely to die from malnutrition and disease. -if a family faces ongoing poverty, the parents may choose to have many children to ensure that some will survive to adulthood. -people are willing to risk having fewer children only if they are sure that their children will live and that the family can develop other economic assets (skills, businesses, land). -breaking the cycle relieving poverty and hunger, then, may be a necessary first step in curbing population growth. -when people attain better access to health care, education, and family planning, the death rate falls. -at first, births outnumber deaths, but as the standard of living continues to improve, families become willing to risk having fewer children. -then the birth rate falls. -thus improvements in living standards help stabilize the population. -the link between improved economic status and slowed population growth has been demonstrated in several countries. -central to achieving this success is sustain- able development that includes not only economic growth, but a sharing of re- sources among all groups. -where this has happened, population growth has slowed the most: in parts of sri lanka, taiwan, malaysia, and costa rica, for example. -where economic growth has occurred but only the rich have grown richer, popula- tion growth has remained high. -examples include brazil, the philippines, and thai- land, where large families continue to be a major economic asset for the poor. -s i b r o c / r e n r o h y m e r e j families in developing countries depend on their children to help provide for daily needs. -hunger and the global environment 709 as a society gains economic footing, education also becomes a higher priority. -a society that educates its children, both males and females, experiences a drop in birth rates. -education, particularly for girls and women, brings improvements in family life, including improved nutrition, better sanitation, effective birth control, and elevated status. -with improved conditions, more infants live to adulthood, making smaller families feasible. -in summary more people means more mouths to feed, which worsens the problems of poverty and hunger. -poverty and hunger, in turn, encourage parents to have more children. -breaking this cycle requires improving the economic status of the people and providing them with health care, education, and family planning. -environmental degradation and hunger hunger, poverty, and overpopulation interact with another force: environmental degradation. -the environment suffers as more and more people must share fewer and fewer resources. -in developing countries, people living in poverty sell everything they own to obtain money for food, even the seeds that would have provided next year s crops. -they cut trees for firewood or timber to sell, and then they lose the soil to erosion. -without these resources, they become poorer still. -thus poverty con- tributes to environmental ruin, and the ruin leads to hunger. -environmental degra- dation threatens the world s ability to produce enough food to feed its many people and the vicious cycle of poverty, population growth, and environmental degradation continues. -environmental limitations in food production environmental problems that are slowing food production include: soil erosion, compaction, and salinization due to overtillage and overirrigation result in extensive loss of productive croplands. -deforestation and desertification due to overgrazing lead to soil erosion. -air pollution produced from the burning of fossil fuels damages crops and depletes the ozone. -ozone depletion allows harmful radiation from the sun to damage crops, espe- cially radiation-sensitive crops such as soybeans. -climate changes are caused by destruction of forests and concentration of heat-trapping carbon dioxide produced by fossil fuels. -a rise in global tem- perature may reduce soil moisture, impair pollination of major food crops such as rice and corn, slow growth, weaken disease resistance, and disrupt many other factors affecting crop yields.22 water pollution from agricultural sediments, salts, fertilizers, pesticides, and manure limits agricultural yields, drinking water, and fishery production. -water scarcity due to overuse of surface and ground water for irrigation may limit human population growth even before food scarcity does. -in many ar- eas, the supplies of fresh water are already inadequate to fully support the survival of crops, livestock, and people.23 extensive overgrazing is causing rangelands to deteriorate. -in nearly all devel- oping countries, the food needs of livestock now exceed the capacity of their rangelands. -y m a l a / d t l l a n o i t a n r e t n i s o i d u t s t l o h without water, croplands become deserts. -fossil fuels: coal, oil, and natural gas. -710 chapter 20 world agriculture produces enough food to provide each person with 2720 kcal/day. -overfishing and water pollution are destroying fisheries and diminishing the supply of seafood. -all in all, environmental problems are reducing the world s ability to feed its people and keep them healthy.24 other limitations in food production with crop fields, rangelands, and fish yields diminishing, can advances in agricul- ture compensate for the losses caused by environmental degradation? -historically, agriculture has yields by making greater investments in irrigation, fertilizer, and ge- netic strains. -today, however, the contributions these measures can make are reach- ing their limits, in part because they have also created environmental problems. -irrigation can no longer compensate by improving crop yields because almost all the land that can benefit from irrigation is already receiving it. -in fact, rising con- centrations of salt in the soil a by-product of irrigation are lowering yields on nearly a quarter of the world s irrigated cropland. -nor can fertilizer use significantly enhance agricultural production. -much of the fertilizing that can be done is being done and with great effect; fertilizer use supports some 40 percent of the world s to- tal crop yields. -adding more fertilizer, however, brings no further rise in yield and adds to the pollution of nearby waterways. -as for the development of high-yielding strains of crops, recent advances have been dramatic, but even they may be inade- quate to change the overall trends. -furthermore, the raw materials necessary for de- veloping new crops have become less available as genetic variation for many plant species is lost. -of the 5000 food plants grown throughout the world a few centuries ago, only 150 are cultivated in commercial agriculture today. -most of the world s population relies on only five cereals, three legumes, and three root crops to meet their energy needs. -even among these, valuable strains are vanish- ing. -the world still produces enough food to feed all of its people, and the problem of hunger today remains a problem of unequal distribution of land to grow crops or income to purchase foods. -if present trends continue, however, the time is fast approaching when there will be an absolute deficit of food. -this conclusion seems inescapable. -the world s increasing population threatens the world s capacity to produce adequate food. -until the nations of the world resolve the population prob- lem, they can neither support the lives of people already born nor remedy global trends toward environmental deterioration. -and to resolve the population prob- lem, a necessary first step is to remedy the poverty problems, for reasons already discussed. -of the 70 million people being added to the population each year, 95 percent are born in the most poverty-stricken areas of the world. -in summary increasing environmental degradation reduces our ability to produce enough food to feed the world s people. -the rapid increase in the world s population exacerbates the situation. -solutions n o t s o b k c o t s - n o s r e t e p a s l e slowly but surely, improvements are evident in developing nations. -most nations have seen a rise in their gross domestic product, a key measure of economic well- being. -adult literacy rates and the proportion of children being sent to school have risen. -the proportion of undernourished people has declined. -optimism abounds, though problems remain. -the keys to solving the world s hunger, poverty, and environmental problems are in the hands of both the poor and the rich nations but require different efforts each person s choice to get involved and be heard can help lead to needed change. -hunger and the global environment 711 from them. -the poor nations need to provide contraceptive technology and family planning information to their citizens, develop better programs to assist the poor, and slow and reverse the destruction of environmental resources. -the rich nations need to stem their wasteful and polluting uses of resources and energy, which are contributing to global environmental degradation. -they also must become willing to ease the debt burden that many poor nations face. -sustainable development worldwide many nations now recognize that improving all nations economies is a prerequisite to meeting the world s other urgent needs: hunger relief, population stabilization, environmental preservation, and sustainable resources. -more than 100 nations have agreed to a set of principles of sustainable development development that would equitably meet both the economic and the environmental needs of present and future generations. -they recognize that relieving poverty will help relieve envi- ronmental degradation and hunger. -to rephrase a well-known adage: if you give a man a fish, he will eat for a day. -if you teach him to fish and enable him to buy and maintain his own gear and bait, he will eat for a lifetime and help to feed others. -unlike food giveaways and money doles, which are only stop-gap measures, social programs that perma- nently improve the lives of the poor can permanently solve the hunger problem. -s o t o h p d l r o w e d i w / p a activism and simpler lifestyles at home every segment of our society can join in the fight against hunger, poverty, and envi- ronmental degradation. -the federal government, the states, local communities, big business and small companies, educators, and all individuals, including dietitians and foodservice managers, have many opportunities to resolve these problems. -government action government policies can change to promote sustainability. -for example, the government can use tax dollars and other resources to develop en- ergy conservation services and crop protection. -business involvement businesses can take the initiative to help; some already have. -several large corporations are major supporters of antihunger programs. -many grocery stores and restaurants participate in food recovery programs by giv- ing their leftover foods to community distribution centers. -education educators, including nutrition educators, can teach others about the un- derlying social and political causes of poverty, the root cause of hunger. -at the college level, they can teach the relationships between hunger and population, hunger and environmental degradation, hunger and the status of women, and hunger and global economics. -they can advocate legislation to address these problems. -they can teach the poor to develop and run nutrition programs in their own communities and to fight on their own behalf for antipoverty, antihunger legislation. -foodservice efforts dietitians and foodservice managers have a special role to play, and their efforts can make an impressive difference. -their professional organization, the ada, urges members to conserve resources and minimize waste in both their pro- fessional and their personal lives.25 in addition, the ada urges its members to educate themselves and others on hunger, its consequences, and programs to fight it; to conduct research on the effectiveness and benefits of programs; and to serve as advocates on the local, state, and national levels to help end hunger in the united states.26 globally, the ada supports programs that combat malnutrition, provide food security, promote self- sufficiency, respect local cultures, protect the environment, and sustain the economy.27 individual choices individuals can assist the global community in solving its poverty and hunger problems by joining and working for hunger-relief organiza- tions (see table 20-1 on p. 712). -they can also support organizations that lobby for the needed changes in economic policies toward developing countries. -the fight against hunger depends on the help- ing hands of caring volunteers. -sustainable: able to continue indefinitely; using resources at such a rate that the earth can keep on replacing them and producing pollutants at a rate with which the environment and human cleanup efforts can keep pace, so that no net accumulation of pollution occurs. -712 chapter 20 table 20-1 hunger-relief organizations action without borders 79 fifth ave., 17th floor new york, ny 10118 (212) 843-3973 www.idealist.org bread for the world 50 f st. nw, suite 500 washington, dc 20001 (800) 82-bread or (800) 822-7323 (202) 639-9400; fax (202) 639-9401 www.bread.org center on hunger and poverty brandeis university mailstop 077 waltham, ma 02454 (781) 736-8885 www.centeronhunger.org community food security coalition p.o. -box 909 venice, ca 90294 (310) 822-5410 www.foodsecurity.org congressional hunger center 2291 2 pennsylvania ave. washington, dc 20003 (202) 547-7022 www.hungercenter.org hungerweb tufts nutrition nutrition.tufts.edu/academic/ hungerweb/overview oxfam america 26 west st. boston, ma 02111-1206 (800) 77-oxfam or (800) 776-9326 www.oxfamamerica.org pan american health organization 525 23rd st. nw washington, dc 20037 (202) 974-3000 www.paho.org second harvest 35 e. wacker dr., #2000 chicago, il 60601 (800) 771-2303 www.secondharvest.org society of st. andrew 3383 sweet hollow rd. -big island, va 24526 (800) 333-4597 www.endhunger.org food and agriculture organization (fao) of the united nations 2175 k st. nw, suite 300 washington, dc 20437 (202) 653-2400 www.fao.org united nations children s fund (unicef) 3 united nations plaza new york, ny 10017-4414 (212) 326-7035 www.unicef.org world food program via vittorio emanuele orlando, 83 rome, italy 00148 www.wfp.org world health organization (who) 525 23rd st. nw washington, dc 20037 (202) 974-3000 www.who.org world hunger year (why) 505 eighth ave., 21st floor new york, ny 10018-6582 (800) gleanit www.worldhungeryear.org a popular adage urges us to think glob- ally, act locally. -most importantly, all individuals can try to make lifestyle choices that con- sider the environmental consequences. -many small decisions each day have major consequences for the environment. -the accompanying how to describes how consumers can conserve resources and minimize waste when making food-related choices. -how to make environmentally friendly food-related choices food production taxes environmental re- sources and causes pollution. -consumers can make environmentally friendly choices at every step from food shopping to cook- ing and use of kitchen appliances to serv- ing, cleanup, and waste disposal. -food shopping transportation: whenever possible, walk or ride a bicycle; use car pools and mass transit. -shop only once a week, share trips, or take turns shopping for each other. -when buying a car, choose an energy- efficient one. -food choices: choose foods low on the food chain; that is, eat more plants and fewer animals that eat plants (this suggestion complements the dietary guidelines for eating for good health). -eat small portions of meat; select range-fed beef, buffalo, poultry, and fish. -select local foods; they require less trans- portation, packaging, and refrigeration. -food packages: whenever possible, select foods with no packages; next best are minimal, reusable, or recyclable ones. -buy juices and sodas in large glass or recy- clable plastic bottles (not small individual cans or cartons); grains in bulk (not sepa- rate little packages); and eggs in pressed fiber cartons (not foam, unless it is recycled locally). -carry reusable string or cloth shopping bags; alternatively, ask for plastic bags if they are recyclable. -gardening grow some of your own food, even if it is only herbs planted in pots on your kitchen windowsill. -compost all vegetable scraps, fruit peel- ings, and leftover plant foods. -cooking food cook foods quickly in a stir-fry, pressure cooker, or microwave oven. -when using the oven, bake a lot of food at one time and keep the door closed tightly. -use nondisposable utensils, dishes, and pans. -use pumps instead of spray products. -kitchen appliances use fewer small electrical appliances; open cans, mix batters, sharpen knives, and chop vegetables by hand. -when buying a large appliance, choose an energy-efficient one. -consider solar power to meet home electri- cal needs. -set the water heater at 130 f (54 c), no hotter; put it on a timer; wrap it and the hot-water pipes in insulation; install water- saving faucets. -food serving, dish washing, and waste disposal use real plates, cups, and glasses instead of disposable ones. -use cloth towels and napkins, reusable storage containers with lids, reusable pans, and dishcloths instead of paper towels, plastic wrap, plastic storage bags, alu- minum foil, and sponges. -run the dishwasher only when it is full. -recycle all glass, plastic, and aluminum. -these suggested lifestyle changes can easily be extended from food to other areas. -hunger and the global environment 713 the personal rewards of the behaviors presented in the previous how to are many, from saving money to the satisfaction of knowing that you are treading lightly on the earth. -but do they really help? -they do, if enough people join in. -be- cause we number more than 6 billion, individual actions can add up to exert an immense impact. -be part of the solution, not part of the problem, another adage says. -in other words, don t waste time or energy moaning and groaning about how bad things are: do something to improve them. -this adage is as applicable to today s global environmental problems as it is to an unwashed dish in the kitchen sink. -they are our problems: human beings created them, and human beings must solve them. -in summary the global environment, which supports all life, is deteriorating, largely be- cause of our irresponsible use of resources and energy. -governments, busi- nesses, and all individuals have many opportunities to make environmentally conscious choices, which may help solve the hunger problem, improve the quality of life, and generate jobs. -personal choices, made by many people, can have a great impact. -a s a n we do not inherit the earth from our ances- tors, we borrow it from our children. -ascribed to chief seattle, a 19th century native ameri- can leader. -nutrition portfolio www.thomsonedu.com/thomsonnow your choice to get involved in the fight against hunger whether in your commu- nity or across the globe can make a big difference in the health and survival of others. -find out about the hunger-relief programs in your area. -write to your legislators and voice your opinions on issues such as food assis- tance programs, environmental degradation, and international debt relief. -consider which environmentally friendly behaviors you are willing to adopt when making food-related choices. -nutrition on the net for further study of topics covered in this chapter, log on to www.thomsonedu .com/thomsonnow. -go to chapter 20, then to nutrition on the net. -explore the problems of hunger, malnutrition, and food insecurity at the feeding minds, fighting hunger site: www.feedingminds.org learn about constructive, community-based solutions to the problems of poverty and hunger within and between the public and private sectors from the national hunger clearinghouse: www.worldhungeryear.org/nhc tight budget from the usda cookbook entitled recipes and tips for healthy, thrifty meals : www.usda.gov/cnpp review the best practices manual for food recovery and gleaning at the usda food and nutrition service site: www.fns.usda.gov/fdd/gleaning/gleanintro.htm find information on feeding the hungry from the emer- gency food and shelter program: www.efsp.unitedway.org donate free food at the hunger site: www.thehungersite .com visit the usda food stamp program: www.fns.usda.gov/fsp see table 20-1 (on p. 712) for additional websites. -download recipes, sample menus, and numerous tips for planning, shopping for, and cooking healthy meals on a 714 chapter 20 study questions to assess your understanding of chapter topics, take the student practice test and explore the modules recommended in your personalized study plan. -log onto www.thomsonedu.com/thomsonnow. -these questions will help you review the chapter. -you will find the answers in the discussions on the pages provided. -1. identify some reasons why hunger is present in a coun- try as wealthy as the united states. -(pp. -702 703) 2. identify some reasons why hunger is present in the developing countries of the world. -(pp. -705 706) 3. explain why relieving environmental problems will also help to alleviate hunger and poverty. -(pp. -709 710) 4. discuss the different paths by which rich and poor countries can attack the problems of world hunger and the environment. -(p. 711) 5. describe some strategies that consumers can use to mini- mize negative environmental impacts when shopping for food, preparing meals, and disposing of garbage. -(p. 712) these multiple choice questions will help you prepare for an exam. -answers can be found on p. 715. -1. food insecurity refers to the: a. uncertainty of foods safety. -b. fear of eating too much food. -c. limited availability of foods. -d. reliability of food production. -2. the most common cause of hunger in the united states is: a. poverty. -b. alcohol abuse. -c. mental illness. -d. lack of education. -3. food stamp debit cards cannot be used to purchase: a. tomato plants. -b. birthday cakes. -c. cola beverages. -d. laundry detergent. -4. which action is not typical of a food recovery program? -a. gathering potatoes from a harvested field b. collecting overripe tomatoes from a wholesaler c. offering food stamp debit cards to low-income people d. delivering restaurant leftovers to a community shelter 5. the primary cause of the worst famine in the 20th century was: a. armed conflicts. -b. natural disasters. -c. food contaminations. -d. government policies. -6. the most likely cause of death in malnourished children is: a. growth failure. -b. diarrheal disease. -c. simple starvation. -d. vitamin a deficiency. -7. which of the following is most critical in providing food to all the world s people? -a. decreasing air pollution b. increasing water supplies c. decreasing population growth d. increasing agricultural land 8. which of these items is the most environmentally benign choice? -a. sponges b. plastic bags c. aluminum foil d. cotton towels 9. which of these methods uses the most fuel? -a. baking b. stir-frying c. microwaving d. pressure cooking 10. which of these purchases is the best choice, for environmental reasons? -a. fresh fish from a local merchant b. frozen fish from a developing country c. canned fish from a nationally known food manufacturer d. packaged fish from the freezer section of a local supermarket hunger and the global environment 715 9. drewnowski and specter, 2004. -10. s. j. jones and e. a. frongillo, the modify- ing effects of food stamp program participa- tion on the relation between food insecurity and weight change in women, journal of nutrition 136 (2006): 1091 1094; s. j. jones and coauthors, lower risk of overweight in school-aged food insecure girls who partici- pate in food assistance, archives of pediatrics and adolescent medicine 157 (2003): 780 784. -11. position of the american dietetic associa- tion: food insecurity and hunger in the united states, journal of the american dietetic association 106 (2006): 446 458. -12. usda food and nutrition service, www.fns.usda.gov/fsp, site visited august 30, 2006. -13. usda food and nutrition service, www.fns.usda.gov/fsp, site visited august 30, 2006. -14. c. mccullum and coauthors, evidence- based strategies to build community food security, journal of the american dietetic association 105 (2005): 278 283. -15. food and agriculture organization, the state of food insecurity in the world 2004, www.fao.org, site visited december 7, 2006. -16. j. nielsen and coauthors, malnourished children and supplementary feeding during the war emergency in guinea-bissau in 1998 1999, american journal of clinical nutrition 80 (2004): 1036 1042. -17. food and agriculture organization of the united nations, state of food insecurity in the world 2005. -18. p. a. sanchez and m. s. swaminathan, cutting world hunger in half, science 307 (2005): 357 359; food and agriculture organization of the united nations, state of food insecurity in the world 2005. -19. u. kapil and a. bhavna, adverse effects of poor micronutrient status during childhood and aolescence, nutrition reviews 60 (2002): s84 s90. -20. i. darnton-hill and coauthors, micronutri- ent deficiencies and gender: social and economic costs, american journal of clinical nutrition 81 (2005): 1198s 1205s. -21. l. e. caulfield and coauthors, undernutri- tion as an underlying cause of child deaths associated with diarrhea, pneumonia, malaria, and measles, american journal of clinical nutrition 80 (2004): 193 198; m. pe a and j. bacallao, malnutrition and poverty, annual review of nutrition 22 (2002): 241 253. -22. s. peng and coauthors, rice yields decline with higher night temperature from global warming, proceedings of the national academy of sciences 101 (2004): 9971 9975. -23. w. jury and h. vaux, the role of science in solving the world s emerging water prob- lems, the national academy of sciences, 2004. -24. b. m. kuehn, desertification called global health threat, journal of the american medical association 295 (2006): 2463 2465. -25. position of the american dietetic associa- tion: dietetic professionals can implement practices to conserve natural resources and protect the environment, journal of the american dietetic association 101 (2001): 1221 1227. -26. position of the american dietetic associa- tion, 2006. -27. position of the american dietetic associa- tion: addressing world hunger, malnutri- tion, and food insecurity, journal of the american dietetic association 103 (2003): 1046 1057. references 1. food and agriculture organization of the united nations, state of food insecurity in the world 2005. -2. united states department of agriculture, household food security in the united states, 2005, ers research briefs, available from www.ers.usda.gov/publications. -3. j. s. hampl and r. hill, dietetic approaches to us hunger and food insecurity, journal of the american dietetic association 102 (2002): 919 923. -4. k. m. kempson and coauthors, food man- agement practices used by people with limited resources to maintain food suffi- ciency as reported by nutrition educators, journal of the american dietetic association 102 (2002): 1795 1799. -5. j. t. cook and coauthors, food insecurity is associated with adverse health outcomes among human infants and toddlers, journal of nutrition 134 (2004): 1432 1438. -6. d. f. jyoti, e. a. frongillo, and s. j. jones, food insecurity affects school children s academic performance, weight gain, and social skills, journal of nutrition 135 (2005): 2831 2839. -7. l. m. scheier, what is the hunger-obesity paradox? -journal of the american dietetic association 105 (2005): 883 886. -8. p. e. wilde and j. n. peterman, individual weight change is associated with household food security status, journal of nutrition 136 (2006): 1395 1400; a. drewnowski and s. e. specter, poverty and obesity; the role of energy density and energy costs, american journal of clinical nutrition 79 (2004): 6 16; e. j. adams, l. grummer-strawn, and g. chavez, food insecurity is associated with increased risk of obesity in california women, journal of nutrition 133 (2003): 1070 1074. answers study questions (multiple choice) 1. c 2. a 3. d 4. c 5. d 6. b 7. c 8. d 9. a 10. a highlight 20 progress toward sustainable food production while some individuals are making their own per- sonal lifestyles more environmentally benign, as suggested in chapter 20, others are seeking ways to improve whole sectors of human enterprise, among them, agriculture. -to date, large agricul- tural enterprises have been among the world s biggest resource users and polluters. -is it possible for agriculture to become sustainable? -what can consumers do to ease the environmental burden of food production? -these questions are ad- dressed in this highlight; the accompanying glos- sary presents terms important to these concepts. -resource waste and pollution the current environmental and social costs of agriculture and the food industry take many forms. -among them are resource waste and pollution (including energy overuse). -producing food costs the earth dearly. -to grow food, we clear land prairie, wetland, and forest losing native ecosystems and wildlife. -then we plant crops or graze animals on the land. -on the sea, we harvest fish with little thought of the dwindling supplies or the environmen- tal damage incurred. -planting crops the soil loses nutrients as each crop is taken from it, so fertilizer is applied. -some fertilizer runs off, polluting the waterways and stimulating algae growth. -by the time rivers empty into the seas, the water is unsuitable for most forms of life.1 some plowed soil runs off, which clouds the waterways and interferes with the growth of aquatic plants and animals. -to protect crops against weeds and pests, we apply herbicides and pesticides. -these chemicals also pollute the water and, wher- ever the wind carries them, the air. -most herbicides and pesticides injure more than weeds and pests; they also injure native plants, native insects, and animals that eat those plants and insects. -iron- ically, widespread use of pesticides and herbicides causes pests s e g a m i y t t e g / e n o t s / r e v o t s and weeds to evolve, becoming even more re- sistant. -consequently, farmers must use still more pesticides and herbicides. -these chemi- cals pose hazards for farm workers who handle them, and the residues can create health prob- lems for consumers as well (see chapter 19). -l u a p finally, we irrigate, a practice that causes salts to accumulate on the soil surface. -the wa- ter evaporates, but the salts do not. -as the sur- face soil becomes increasingly salty, plant growth suffers. -irrigation can also deplete the water supply over time because it pulls water from surface waters or from underground; then, the water evap- orates or runs off. -this process, carried to the extreme, can dry up rivers and lakes and lower the water table of a whole region. -a vi- cious cycle develops. -the drier the region becomes, the more the farmers must irrigate, and the more they irrigate, the drier the re- gion becomes. -raising livestock raising livestock also takes a toll. -like plant crops, herds of live- stock occupy land that once maintained itself in a natural state. -the land suffers the losses of native plants and animals, soil ero- sion, water depletion, and desert formation. -alternatively, animals raised in large concentrated areas such as cattle feedlots or giant hog farms create environmental problems when huge masses of animal wastes are produced in the overcrowded, factory-style farms. -these wastes leach into local soils and water supplies, pol- luting them. -to prevent contamination of drinking water, the en- vironmental protection agency suggests several strategies for managing livestock, poultry, and horse waste. -in addition to ma- nure, cows produce large quantities of methane a potent gas that may contribute to global warming. -in addition to the waste problems, animals must be fed; grain is grown for them on other land. -that land may require fertilizers, herbicides, pesticides, and irrigation, too. -in the united states, more cropland is used to pro- duce grains for livestock than to produce grains for people. -figure h20-1 compares the grain required to produce various foods. -g lossary agribusinesses: agriculture practiced on a nonpoint water pollution: water pollution sustainable agriculture: agricultural practices massive scale by large corporations owning vast acreages and employing intensive technological, fuel, and chemical inputs. -caused by runoff from all over an area rather than from discrete point sources. -an example is the pollution caused by runoff from agricultural fields. -that use individualized approaches appropriate to local conditions so as to minimize technological, fuel, and chemical inputs. -716 figure h20-1 pound of bread and one pound of animal weight gain pounds of grain needed to produce one to gain one pound, animals raised for food have to eat many more pounds of grain than it takes to make a pound of bread. -source: idea and data from t.r. -reid, feeding the planet, national geographic, october 1998, pp. -58 74 fishing fishing also incurs environmental costs. -fishing easily becomes overfishing and depletes stocks of the very fish that people need to eat. -some fishing methods (such as nets and filament line) kill nonfood species and deplete large populations of aquatic ani- mals, such as dolphins. -also, fishing is energy-intensive, requiring fuel for boats, refrigeration, processing, packing, and transport. -water pollution incurs health risks when people eat contaminated fish. -bioaccumulation of toxins in fish is a serious problem in some areas; in others it rules out fish consumption altogether. -energy overuse the entire food industry, whether based on growing crops, rais- ing livestock, or fishing, requires energy, which entails burning fossil fuels. -massive fossil fuel use threatens our planet by causing air and water pollution, global warming, ozone depletion, and other environmental and political problems. -in the united states, the food industry consumes about 20 percent of all the energy the nation uses. -most of this energy is used to run farm machinery and to produce fertilizers and pesti- cides. -energy is also used to prepare, package, transport, refriger- ate, store, cook, and wash our foods. -progress toward sustainable food production 717 national academy of sciences has reported that agriculture is the largest single source of nonpoint water pollution in the na- tion. -pollution from point sources, such as sewage plants or fac- tories, is relatively easy to control, but runoff from fields and pastures enters waterways from so many broad regions that it is nearly impossible to control. -agriculture is destroying its own foundation. -agricultural activ- ities have ruined millions of acres of fertile land that will be impos- sible to reclaim. -agriculture is also weakening its own underpinnings by failing to conserve species diversity. -by the year 2050, some 40,000 more plant species may become extinct. -the united nations food and agriculture organization attributes many of the losses, which are already occurring daily, to modern farming practices, as well as to population growth. -the increasing uniformity of global eating habits also contributes. -wheat, rice, and maize pro- vide more than half of the food energy around the world; only an- other two dozen crops provide the remainder. -as people everywhere eat the same limited array of foods, local regions na- tive, genetically diverse plants no longer seem worth preserving. -yet, in the future, as the climate warms and the earth changes, those may be the very plants that people will need for food sources. -a wild species of corn that grows in a dry climate, for ex- ample, might contain the genetic information necessary to help make domestic corn resistant to drought. -(highlight 19 offered several examples of how biotechnology is being used to improve food crops.) -the culprits that attend the growing of crops land clearing; irrigation; fertilizer, pesticide, and herbicide overuse; and loss of genetic diversity have taken a tremendous toll on the earth. -in short, our ways of producing foods are, for the most part, not sustainable. -sustainable agriculture for each of the problems described above, agricultural solutions are being devised, and indeed, some are being put into practice. -fully utilizing sustainable agriculture techniques across the country will require some new learning. -sustainable agriculture is not one system but a set of practices that can be adapted to meet the particular needs of a local area. -the crop yields from farms that employ these practices often compare favorably with those from farms using less sustainable methods.2 table h20-1 (p. 718) contrasts low-input, sustainable agriculture methods with high- input, unsustainable methods. -many sustainable techniques are not really new, incidentally; they would be familiar to our great grandparents. -farmers today are rediscovering the benefits of old techniques as they adapt and experiment with them in the search for sustainable methods. -consumer choices the cumulative effects many national and international agencies are concerned about the environmental ramifications of agriculture. -the prestigious table h20-2 (p. 718) lists several ways to save energy in the pro- duction of food. -the last item in the table suggests that con- sumers should eat low on the food chain. -for the most part, that 718 highlight 20 table h20-1 agricultural methods compared unsustainable methods sustainable methods grow the same crop repeatedly on the same patch of land. -this takes more and more nutrients out of the soil, making fertilizer use necessary; favors soil erosion; and invites weeds and pests to become established, making pesticide use necessary. -rotate crops. -this increases nitrogen in the soil so there is less need to use fertilizers. -if used with appropriate plowing methods, rotation reduces soil erosion. -rotation also reduces problems caused by weeds and pests. -use fertilizers generously. -excess fertilizer pollutes ground and surface water and costs both farmers household money and consumers tax money. -reduce the use of fertilizers, and use livestock manure more effectively. -store manure during the nongrowing season and apply it during the growing season. -feed livestock in feedlots where their manure produces a major water pollution probem. -piled in heaps, it also releases methane, a global- warming gas. -spray herbicides and pesticides over large areas to wipe out weeds and pests. -alternate nutrient-devouring crops with nutrient-restoring crops, such as legumes. -compost on a large scale, including all plant residues not harvested. -plow the compost into the soil to improve its water-holding capacity. -feed livestock or buffalo on the open range where their manure will fertilize the ground on which plants grow and will release no methane. -alternatively, at least collect feedlot animals manure and use it for fertil- izer or, at the very least, treat it before release. -apply ingenuity in weed and pest control. -use precision techniques if affordable or rotary hoes twice instead of herbicides once. -spot treat weeds by hand. -rotate crops to foil pests that lay their eggs in the soil where last year s crop was grown. -use resistant crops. -use biological controls such as predators that destroy the pests. -plow the same way everywhere, allowing unsustainable water runoff and erosion. -plow in ways tailored to different areas. -conserve both soil and water by using cover crops, crop rotation, no-till planting, and contour plowing. -inject animals with antibiotics to prevent disease in livestock. -maintain animals health so that they can resist disease. -irrigate on a large scale. -irrigation depletes water supplies and irrigate only during dry spells and apply only spot irrigation. -concentrates salts in the soil. -table h20-2 agricultural techniques sustainable energy-saving use machinery scaled to the job at hand, and operate it at efficient speeds. -combine operations. -harrow, plant, and fertilize in the same operation. -use diesel fuel. -use solar and wind energy on farms. -use methane from manure. -be open-minded to alternative energy sources. -save on technological and chemical inputs, and spend some of the sav- ings paying people to do manual jobs. -increasing labor has been consid- ered inefficient reverse this thinking. -creating more jobs is preferable to using more machinery and fuel. -partially return to the techniques of using animal manure and crop rotation. -this will save energy because chemical fertilizers require much energy to produce. -choose crops that require few resources (fertilizer, pesticides, irrigation). -educate people to cook food efficiently and to eat low on the food chain. -means eating more foods derived from plants and fewer foods derived from animals. -it also means eating more foods grown lo- cally and fewer foods produced elsewhere. -plant versus animal some foods require more energy for their production than others. -the least energy is needed for grains: it takes about one-third kcalorie of fuel to produce each kcalorie of grain. -fruits and veg- etables are intermediate, and most animal-derived foods require from 10 to 90 kcalories of fuel per kcalorie of edible food. -in gen- eral, meat-based diets require much more energy, as well as more land and water, than do plant-based diets.3 an exception is live- stock raised on the open range; these animals require about as much energy as most plant foods.4 we raise so much more grain- fed, than range-fed, livestock, however, that the average energy requirement for meat production is high. -figure h20-2 shows how much less fuel vegetarian diets require than meat-based di- ets and shows that vegan diets require the least fuel of all. -to support our meat intake, we maintain several billion livestock, about four times our own weight in animals. -livestock consume ten times as much grain each day as we do. -we could use much of that grain to make grain products for ourselves and for others around the world. -making this shift could free up enough grain to feed 400 mil- lion people while using less fuel, water, and land. -part of the solution to the livestock problem may be to cease feeding grain to animals and return to grazing them on the open range, which can be a sustainable practice. -ranchers have to manage the grazing carefully to hold the cattle s numbers to what the land can support without environmental degradation. -to accomplish this, the economic benefits of traditional livestock and feed-growing operations would have to end. -if producers were to pay the true costs of the environmental damage incurred by irrigation water, fertilizers, pesticides, and fuels, the prices of progress toward sustainable food production 719 figure h20-2 amounts of fuel required to feed people eating at different points on the food chain three people who eat differently are compared here. -each has the same energy intake: 3300 kcalories a day. -the fossil fuel amounts necessary to produce these different diets are calculated based on u.s. conditions. -the meat eater consumes a typical u.s. diet of meat, other animal products, and plant foods: the lacto-ovo-vegetarian eats a diet that excludes meats, but includes milk products and eggs: the vegan eats a diet of plant foods only: meat and animal products 2000 kcal plant foods 1300 kcal l l a a c c k k 0 0 0 0 9 9 , , 3 3 3 3 plant foods 2300 kcal animal products 1000 kcal l l a a c c k k 0 0 0 0 9 9 , , 8 8 1 1 fuel required to produce this food fuel required to produce this food source: adapted from d. pimentel, food, energy and the future of society (boulder, colo.: associated university press, 1980), figure 5, p. 27. plant foods 3300 kcal 0 0 9 , 9 l a c k fuel required to produce this food meats might double or triple. -according to classic economic the- ory, people would then buy less meat (reducing demand), and producers would respond by producing less meat (reducing supply). -meat production would then fall to a sustainable level. -the united nations describes a nation s impact on the envi- ronment as its ecological footprint a measure of the resources used to support a nation s consumption of food, materials, and energy. -this measure takes into account the two most challeng- ing aspects of sustainability per capita resource consumption and population growth. -as figure h20-3 shows, the people of north america are the world s greatest consumers on a per capita basis. -some have estimated that it would take four more planet earths to accommodate every person in the world using resources at the level currently used in the united states.5 figure h20-3 argue that they don t go far enough. -the most ecologically respon- sible diets are also based on locally grown products. -on average, an item of food is transported 1500 miles before it is eaten. -that our foods now travel more than we do has several costly ramifications. -buying globally is: energetically costly. -foods must be refrigerated and trans- ported thousands of miles to provide a full array of all pro- duce all year round. -socially unjust. -farmers in impoverished countries, where the people are malnourished, are paid meager wages to grow food for wealthy nations. -ecological footprints some consumers are taking action to do their part to solve some of these problems. -some are choosing smaller portions of meat or selecting range-fed beef or buffalo only. -livestock on the range eat grass, which people cannot eat. -rangeburger buffalo also offers nutrient ad- vantages over grain-fed beef because it is lower in fat and because the fat has more polyunsatu- rated fatty acids, including the omega-3 type. -some consumers are opting for vegetarian, and even vegan, diets at least occasionally. -vegetarian diets have less of an environmental impact than meat-based diets.6 shifting to a fish diet does not appear to be a practical alter- native at present, although fish farming shows promise of providing nutritious food at a price both people and the environment can afford. -local versus global plant-centered diets have an environmental ad- vantage over meat-based diets, but some would the width of a bar represents the region s population, and the height represents per capita consumption (in terms of area of productive land or sea required to pro- duce the natural resources consumed). -thus the footprint of the bar represents the region s total consumption. -for example, asia s population is more than ten times greater than north america s, but because its consumption is only one-sixth as large, their footprints are similar in size. -12 10 8 6 4 2 0 n o s r e p r e p s t i n u a e r a key: north america western europe central and eastern europe middle east and central asia latin america and caribbean asia / pacific africa 299 384 343 307 484 3,222 710 population (millions) 720 highlight 20 locally grown foods offer benefits to both the local economy and the global environment. -nutrition on the net for furthur study of topics covered in this highlight, log on to www .thomsonedu.com/thomsonnow. -go to chapter 20, then to highlights nutrition on the net. -visit the usda alternative farming systems information center: www.nal.usda.gov/afsic references economically unwise. -it supports agribusinesses that buy land and labor cheaply in foreign countries instead of sup- porting local farmers raising crops in our communities. -biologically risky. -highly perishable foods are shipped from countries with unsafe drinking water and sanitation practices. -for all these reasons, consumers can best improve the global en- vironment by buying locally. -adopting a local diet presents a bit of a challenge at first, especially when local fruits and vegetables are out of season. -but a nutritionally balanced diet of delicious foods is quite possible with a little creative planning. -chapter 20 and this highlight have presented many problems and have suggested that, although many of the problems are global in scope, the solutions depend on the actions of individual people at the local level. -on learning of this, concerned people may take a perfectionist attitude, believing that they should be doing more than they realistically can, and so feel defeated. -yet, striving for perfection, even while falling short, is a way to achieve progress and is well worth celebrating. -a positive attitude can bring about improvement, and sometimes improvement is enough. -celebrate the changes that are possible today by making them a permanent part of your life; do the same with changes that become possible tomorrow and every day thereafter. -the re- sults may surprise you. -i s b r o c / n o t r a b l u a p visit the sustainable agriculture research and education program at uc davis and the leopold center for sustain- able agriculture at ia state: www.sarep.ucdavis.edu and www.leopold.iastate.edu 1. j. raloff, limiting dead zones: how to curb river pollution and save the gulf of mexico, science news 165 (2004): 378 380. -2. s. peng and coauthors, rice yields decline with higher night temperature from global warming, proceedings of the national academy of sciences 101 (2004): 9971 9975. -3. d. pimentel and m. pimentel, sustainability of meat-based and plant-based diets and the environment, american journal of clinical nutrition 78 (2003): 660s 663s. -4. j. robinson, grass fed basics: key differ- ences between conventional and pasture animal production, 2002-2003, available at www.eatwild.com/basics.html. -5. e. o. wilson, the bottleneck, scientific american, february 2002, pp. -82 91. -6. l. reijnders and s. soret, quantification of the environmental impact of different dietary protein choices, american journal of clinical nutrition 78 (2003): 664s 668s; c. leitzmann, nutrition ecology: the contribu- tion of vegetarian diets, american journal of clinical nutrition 78 (2003): 657s 659s. -appendixes appendix a cells, hormones, and nerves appendix b basic chemistry concepts appendix c biochemical structures and pathways appendix d measures of protein quality appendix e nutrition assessment appendix f physical activity and energy requirements appendix g united states: exchange lists appendix h table of food composition appendix i who: nutrition recommendations canada: guidelines and meal planning appendix j healthy people 2010 taylor s. kennedy/getty images a x i d n e p p a a-2 appendix a contents the cell the hormones the nervous system putting it together g lossary of cell structures cell: the basic structural unit of all living things. -cell membrane: the thin layer of tissue that surrounds the cell and encloses its contents; made primarily of lipid and protein. -chromosomes: a set of structures within the nucleus of every cell that contains the cell s genetic material, dna, associated with other materials (primarily proteins). -cytoplasm (sigh-toh-plazm): the cell contents, except for the nucleus. -cyto (cid:2) cell plasm (cid:2) a form cytosol: the uid of cytoplasm; contains water, ions, nutrients, and enzymes. -endoplasmic reticulum (en-doh-plaz-mic reh-tic-you-lum): a complex network of intracellular membranes. -the rough endoplasmic reticulum is dotted with ribosomes, where protein synthesis takes place. -the smooth endoplasmic reticulum bears no ribosomes. -endo (cid:2) inside plasm (cid:2) the cytoplasm golgi (goal-gee) apparatus: a set of membranes within the cell where secretory materials are packaged for export. -lysosomes (lye-so-zomes): cellular organelles; membrane-enclosed sacs of degradative enzymes. -lysis (cid:2) dissolution mitochondria (my-toh-kon-dree-uh); singular mitochondrion: the cellular organelles responsible for producing atp aerobically; made of membranes (lipid and protein) with enzymes mounted on them. -mitos (cid:2) thread (referring to their slender shape) chondros (cid:2) cartilage (referring to their external appearance) nucleus: a major membrane-enclosed body within every cell, which contains the cell s genetic material, dna, embedded in chromosomes. -nucleus (cid:2) a kernel organelles: subcellular structures such as ribosomes, mitochondria, and lysosomes. -organelle (cid:2) little organ cells, hormones, and nerves this appendix is offered as an optional chapter for readers who want to enhance their understanding of how the body coordinates its activities. -it presents a brief summary of the structure and function of the body s basic working unit (the cell) and of the body s two major regulatory systems (the hormonal system and the nervous system). -the cell the body s organs are made up of millions of cells and of materials produced by them. -each cell is specialized to perform its organ s functions, but all cells have com- mon structures (see the accompanying glossary and figure a-1). -every cell is con- tained within a cell membrane. -the cell membrane assists in moving materials into and out of the cell, and some of its special proteins act as pumps (described in chapter 6). -some features of cell membranes, such as microvilli (chapter 3), permit cells to interact with other cells and with their environments in highly speci c ways. -inside the membrane lies the cytoplasm, which is lled with cytosol, or cell uid. -the cytoplasm contains much more than just uid, though. -it is a highly or- ganized system of bers, tubes, membranes, particles, and subcellular organelles as complex as a city. -these parts intercommunicate, manufacture and exchange mate- rials, package and prepare materials for export, and maintain and repair themselves. -within each cell is another membrane-enclosed body, the nucleus. -inside the nu- cleus are the chromosomes, which contain the genetic material, dna. -the dna en- codes all the instructions for carrying out the cell s activities. -the role of dna in coding for cell proteins is summarized in figure 6-7 on p. 188. chapter 6 also describes the va- riety of proteins produced by cells and the ways they perform the body s work. -among the organelles within a cell are ribosomes, mitochondria, and lyso- somes. -figure 6-7 brie y refers to the ribosomes; they assemble amino acids into proteins, following directions conveyed to them by rna. -the mitochondria are made of intricately folded membranes that bear thou- sands of highly organized sets of enzymes on their inner and outer surfaces. -mito- chondria are crucial to energy metabolism (described in chapter 7) and muscles conditioned to work aerobically are packed with them. -their presence is implied whenever the tca cycle and electron transport chain are mentioned because the mitochondria house the needed enzymes. -* the lysosomes are membranes that enclose degradative enzymes. -when a cell needs to self-destruct or to digest materials in its surroundings, its lysosomes free their enzymes. -lysosomes are active when tissue repair or remodeling is taking place for example, in cleaning up infections, healing wounds, shaping embry- onic organs, and remodeling bones. -besides these and other cellular organelles, the cell s cytoplasm contains a highly organized system of membranes, the endoplasmic reticulum. -the ribosomes may either oat free in the cytoplasm or be mounted on these membranes. -a membranous surface dotted with ribosomes looks speckled under the microscope and is called rough endoplasmic reticulum; such a surface without ribosomes is called smooth. -some intracellular membranes are organized into tubules that collect cellular materi- als, merge with the cell membrane, and discharge their contents to the outside of *for the reactions of glycolysis, the tca cycle, and the electron transport chain, see chapter 7 and appendix c. the reactions of glycolysis take place in the cytoplasm; the conversion of pyruvate to acetyl coa takes place in the mitochondria, as do the tca cycle and electron transport chain reac- tions. -the mitochondria then release carbon dioxide, water, and atp as their end products. -figure a-1 the structure of a typical cell the cell shown might be one in a gland (such as the pancreas) that produces secre- tory products (enzymes) for export (to the intestine). -the rough endoplasmic reticu- lum with its ribosomes produces the enzymes; the smooth reticulum conducts them to the golgi region; the golgi membranes merge with the cell membrane, where the enzymes can be released into the extracellular uid. -cells, hormones, and nerves a-3 cytoplasm golgi apparatus smooth endoplasmic reticulum lysosome cell membrane nucleus chromosomes rough endoplasmic reticulum ribosomes mitochondrion the study of hormones and their effects is endocrinology. -the pituitary gland in the brain has two parts the anterior (front) and the posterior (hind). -ribosomes (rye-boh-zomes): protein-making organelles in cells; composed of rna and protein. -ribo (cid:2) containing the sugar ribose (in rna) some (cid:2) body a a p p e n d i x the cell; these membrane systems are named the golgi apparatus, after the sci- entist who rst described them. -the rough and smooth endoplasmic reticula and the golgi apparatus are continuous with one another, so secretions produced deep in the interior of the cell can be ef ciently transported to the outside and released. -these and other cell structures enable cells to perform the multitudes of functions for which they are specialized. -the actions of cells are coordinated by both hormones and nerves, as the next sections show. -among the types of cellular organelles are receptors for the hor- mones delivering instructions that originate elsewhere in the body. -some hor- mones penetrate the cell and its nucleus and attach to receptors on chromosomes, where they activate certain genes to initiate, stop, speed up, or slow down synthe- sis of certain proteins as needed. -other hormones attach to receptors on the cell surface and transmit their messages from there. -the hormones are described in the next section; the nerves, in the one following. -the hormones a chemical compound a hormone originates in a gland and travels in the bloodstream. -the hormone ows everywhere in the body, but only its target or- gans respond to it, because only they possess the receptors to receive it. -the hormones, the glands they originate in, and their target organs and effects are described in this section. -many of the hormones you might be interested in are included, but only a few are discussed in detail. -figure a-2 (p. a-4) identi es the glands that produce the hormones, and the accompanying glossary de nes the hormones discussed in this section. -hormones of the pituitary gland and hypothalamus the anterior pituitary gland produces the following hormones, each of which acts on one or more target organs and elicits a characteristic response: adrenocorticotropin (acth) acts on the adrenal cortex, promoting the production and release of its hormones. -thyroid-stimulating hormone (tsh) acts on the thyroid gland, pro- moting the production and release of thyroid hormones. -growth hormone (gh) or somatotropin acts on all tissues, promoting growth, fat breakdown, and the formation of antibodies. -g lossary of hormones adrenocorticotropin (ad-ree-noh-kore-tee- koh-trop-in) or acth: a hormone, so named because it stimulates (trope) the adrenal cortex. -the adrenal gland, like the pituitary, has two parts, in this case an outer portion (cortex) and an inner core (medulla). -the realease of acth is mediated by corticotropin-releasing hormone (crh). -aldosterone: a hormone from the adrenal gland involved in blood pressure regulation. -aldo (cid:2) aldehyde angiotensin: a hormone involved in blood pressure regulation that is activated by renin (ren-in), an enzyme from the kidneys. -angio (cid:2) blood vessels tensin (cid:2) pressure ren (cid:2) kidneys antidiuretic hormone (adh): the hormone that prevents water loss in urine (also called vasopressin). -anti (cid:2) against di (cid:2) through ure (cid:2) urine vaso (cid:2) blood vessels pressin (cid:2) pressure calcitonin (kal-see-toh-nin): a hormone secreted by the thyroid gland that regulates (tones) calcium metabolism. -erythropoietin (eh-rith-ro-poy-eh-tin): a hormone that stimulates red blood cell production. -erythro (cid:2) red (blood cell) poiesis (cid:2) creating (like poetry) estrogens: hormones responsible for the menstrual cycle and other female characteristics. -oestrus (cid:2) the egg-making cycle gen (cid:2) gives rise to a-4 appendix a a x i d n e p p a hormones that are turned off by their own effects are said to be regulated by negative feedback. -follicle-stimulating hormone (fsh): a hormone that stimulates maturation of the ovarian follicles in females and the production of sperm in males. -(the ovarian follicles are part of the female reproductive system where the eggs are produced.) -the release of fsh is mediated by follicle-stimulating hormone releasing hormone (fsh rh). -glucocorticoids: hormones from the adrenal cortex that affect the body s management of glucose. -gluco (cid:2) glucose corticoid (cid:2) from the cortex growth hormone (gh): a hormone secreted by the pituitary that regulates the cell division and protein synthesis needed for normal growth (also called somatotropin). -the release of gh is mediated by gh-releasing hormone (ghrh) and gh-inhibiting hormone (ghih). -hormone: a chemical messenger. -hormones are secreted by a variety of endocrine glands in response to altered conditions in the body. -each hormone travels to one or more speci c target tissues or organs, where it elicits a speci c response to maintain homeostasis. -luteinizing (loo-tee-in-eye-zing) hormone (lh): a hormone that stimulates ovulation and the development of the corpus luteum (the small tissue that develops from a ruptured ovarian follicle and secretes hormones); so called because the follicle turns yellow as it matures. -in men, lh stimulates testosterone secretion. -the release of lh is mediated by luteinizing hormone releasing hormone (lh rh). -lutein (cid:2) a yellow pigment figure a-2 the endocrine system these organs and glands release hormones that regulate body processes. -an endocrine gland secretes its product directly into (endo) the blood; for example, the pancreas cells that produce insulin. -an exocrine gland secretes its product(s) out (exo) to an epithelial surface either directly or through a duct; the sweat glands of the skin and the enzyme-producing glands of the pancreas are both examples. -the pancreas is therefore both an endocrine and an exocrine gland. -hypothalamus thymus gland heart adrenal glands (cortex, medulla) kidney ovary placenta (develops in the uterus during pregnancy) female male pituitary gland (anterior, posterior) parathyroid glands thyroid gland stomach pancreas testicle follicle-stimulating hormone (fsh) acts on the ovaries in the female, promoting their maturation, and on the testicles in the male, promoting sperm formation. -luteinizing hormone (lh) also acts on the ovaries, stimulating their maturation, the production and release of progesterone and estrogens, and ovulation; and on the testicles, promoting the production and release of testosterone. -prolactin, secreted in the female during pregnancy and lactation, acts on the mammary glands to stimulate their growth and the production of milk. -each of these hormones has one or more signals that turn it on and another (or others) that turns it off. -among the controlling signals are several hormones from the hypothalamus: corticotropin-releasing hormone (crh), which promotes release of acth, is turned on by stress and turned off by acth when enough has been released. -tsh-releasing hormone (trh), which promotes release of tsh, is turned on by large meals or low body temperature. -gh-releasing hormone (ghrh), which stimulates the release of growth hormone, is turned on by insulin. -gh-inhibiting hormone (ghih or somatostatin), which inhibits the release of gh and interferes with the release of tsh, is turned on by hypo- glycemia and/or physical activity and is rapidly destroyed by body tissues so that it does not accumulate. -fsh/lh releasing hormone (fsh/lh rh) is turned on in the female by nerve messages or low estrogen and in the male by low testosterone. -prolactin-inhibiting hormone (pih) is turned on by high prolactin levels and off by estrogen, testosterone, and suckling (by way of nerve messages). -let s examine some of these controls. -pih, for example, responds to high prolactin levels (remember, prolactin promotes milk production). -high prolactin levels en- sure that milk is made and by calling forth pih ensure that prolactin levels don t get too high. -but when the infant is suckling and creating a demand for milk pih is not allowed to work (suckling turns off pih). -the consequence: pro- lactin remains high, and milk production continues. -demand from the infant thus directly adjusts the supply of milk. -the need is met through the interaction of the nerves and hormones. -as another example, consider crh. -stress, perceived in the brain and relayed to the hypothalamus, switches on crh. -on arriving at the pituitary, crh switches on acth. -then acth acts on its target organ, the adrenal cortex, which responds by producing and releasing stress hormones. -the stress hormones trigger a cas- cade of events involving every body cell and many other hormones. -the numerous steps required to set the stress response in motion make it possible for the body to ne-tune the response; control can be exerted at each step. -these two ex- amples illustrate what the body can do in response to two different stimuli producing milk in response to an infant s need and gearing up for action in an emergency. -the posterior pituitary gland produces two hormones, each of which acts on one or more target cells and elicits a characteristic response: antidiuretic hormone (adh), or vasopressin, acts on the arteries, pro- moting their contraction, and on the kidneys, preventing water excretion. -adh is turned on whenever the blood volume is low, the blood pressure is low, or the salt concentration of the blood is high (see chapter 12). -it is turned off by the return of these conditions to normal. -oxytocin acts during late pregnancy on the uterus, inducing contractions, and during lactation on the mammary glands, causing milk ejection. -oxy- tocin is produced in response to reduced progesterone levels, suckling, or the stretching of the cervix. -hormones that regulate energy metabolism hormones produced by a number of different glands have effects on energy metabolism: insulin from the pancreas beta cells is turned on by many stimuli, including raised blood glucose. -it acts on cells to increase glucose and amino acid uptake into them and to promote the secretion of ghrh. -glucagon from the pancreas alpha cells responds to low blood glucose and acts on the liver to promote the breakdown of glycogen to glucose, the con- version of amino acids to glucose, and the release of glucose into the blood. -thyroxine from the thyroid gland responds to tsh and acts on many cells to increase their metabolic rate, growth, and heat production. -norepinephrine and epinephrine from the adrenal medulla respond to stimulation by sympathetic nerves and produce reactions in many cells that facilitate the body s readiness for ght or ight: increased heart activity, blood vessel constriction, breakdown of glycogen and glucose, raised blood glucose levels, and fat breakdown. -norepinephrine and epinephrine also in- uence the secretion of the many hormones from the hypothalamus that exert control on the body s other systems. -growth hormone (gh) from the anterior pituitary (already mentioned). -glucocorticoids from the adrenal cortex become active during times of stress and carbohydrate metabolism. -cells, hormones, and nerves a-5 a a p p e n d i x norepinephrine and epinephrine were formerly called noradrenalin and adrenalin, respectively. -oxytocin (ock-see-toh-sin): a hormone that stimulates the mammary glands to eject milk during lactation and the uterus to contract during childbirth. -oxy (cid:2) quick tocin (cid:2) childbirth progesterone: the hormone of gestation (pregnancy). -pro (cid:2) promoting gest (cid:2) gestation (pregnancy) sterone (cid:2) a steroid hormone prolactin (proh-lak-tin): a hormone so named because it promotes (pro) the production of milk (lacto). -the release of prolactin is mediated by prolactin- inhibiting hormone (pih). -relaxin: the hormone of late pregnancy. -somatostatin (ghih): a hormone that inhibits the release of growth hormone; the opposite of somatotropin (gh). -somato (cid:2) body stat (cid:2) keep the same tropin (cid:2) make more testosterone: a steroid hormone from the testicles, or testes. -the steroids, as explained in chapter 5, are chemically related to, and some are derived from, the lipid cholesterol. -sterone (cid:2) a steroid hormone thyroid-stimulating hormone (tsh): a hormone secreted by the pituitary that stimulates the thyroid gland to secrete its hormones thyroxine and triiodothyronine. -the release of tsh is mediated by tsh- releasing hormone (trh). -a-6 appendix a a x i d n e p p a every body part is affected by these hormones. -each different hormone has unique effects; and hormones that oppose each other are produced in carefully regulated amounts, so each can respond to the exact degree that is appropriate to the condition. -hormones that adjust other body balances hormones are involved in moving calcium into and out of the body s storage de- posits in the bones: calcitonin from the thyroid gland acts on the bones, which respond by storing calcium from the bloodstream whenever blood calcium rises above the normal range. -it also acts on the kidneys to increase excretion of both calcium and phosphorus in the urine. -calcitonin plays a major role in in- fants and young children, but is less active in adults. -parathyroid hormone (parathormone or pth) from the parathyroid gland responds to the opposite condition lowered blood calcium and acts on three targets: the bones, which release stored calcium into the blood; the kid- neys, which slow the excretion of calcium; and the intestine, which increases calcium absorption. -vitamin d from the skin and activated in the kidneys acts with parathyroid hormone and is essential for the absorption of calcium in the intestine. -figure 12-12 on p. 417 diagrams the ways vitamin d and the hormones calcitonin and parathyroid hormone regulate calcium homeostasis. -another hormone has effects on blood-making activity: erythropoietin from the kidneys is responsive to oxygen depletion of the blood and to anemia. -it acts on the bone marrow to stimulate the making of red blood cells. -another hormone is special for pregnancy: relaxin from the ovaries is secreted in response to the raised progesterone and estrogen levels of late pregnancy. -this hormone acts on the cervix and pelvic ligaments to allow them to stretch so that they can accommodate the birth process without strain. -other agents help regulate blood pressure: renin (an enzyme), from the kidneys, in cooperation with angiotensin in the blood responds to a reduced blood supply experienced by the kidneys and acts in several ways to increase blood pressure. -renin and angiotensin also stimulate the adrenal cortex to secrete the hormone aldosterone. -aldosterone, a hormone from the adrenal cortex, targets the kidneys, which respond by reabsorbing sodium. -the effect is to retain more water in the bloodstream thus, again, raising the blood pressure. -figure 12-3 (on p. 403) in chapter 12 provides more details. -the gastrointestinal hormones several hormones are produced in the stomach and intestines in response to the presence of food or the components of food: gastrin from the stomach and duodenum stimulates the production and re- lease of gastric acid and other digestive juices and the movement of the gi contents through the system. -cholecystokinin from the duodenum signals the gallbladder and pancreas to release their contents into the intestine to aid in digestion. -secretin from the duodenum calls forth acid-neutralizing bicarbonate from the pancreas into the intestine and slows the action of the stomach and its secretion of acid and digestive juices. -gastric-inhibitory peptide from the duodenum and jejunum inhibits the se- cretion of gastric acid and slows the process of digestion. -these hormones are de ned and presented in more detail in chapter 3. the sex hormones there are three major sex hormones: testosterone from the testicles is released in response to lh (described ear- lier) and acts on all the tissues that are involved in male sexuality, promot- ing their development and maintenance. -estrogens from the ovaries are released in response to both fsh and lh and act similarly in females. -progesterone from the ovaries corpus luteum and from the placenta acts on the uterus and mammary glands, preparing them for pregnancy and lactation. -this brief description of the hormones and their functions should suf ce to provide an awareness of the enormous impact these compounds have on body processes. -the other overall regulating agency is the nervous system. -the nervous system the nervous system has a central control system that can evaluate information about conditions within and outside the body, and a vast system of wiring that re- ceives information and sends instructions. -the control unit is the brain and spinal cord, called the central nervous system; and the vast complex of wiring be- tween the center and the parts is the peripheral nervous system. -the smooth functioning that results from the system s adjustments to changing conditions is homeostasis. -the nervous system has two general functions: it controls voluntary muscles in re- sponse to sensory stimuli from them, and it controls involuntary, internal muscles and glands in response to nerve-borne and chemical signals about their status. -in fact, the nervous system is best understood as two systems that use the same or similar path- ways to receive and transmit their messages. -the somatic nervous system controls the voluntary muscles; the autonomic nervous system controls the internal organs. -when scientists were rst studying the autonomic nervous system, they noticed that when something hurt one organ of the body, some of the other organs reacted as if in sympathy for the af icted one. -they therefore named the nerve network they were studying the sympathetic nervous system. -the term is still used today to refer to that branch of the autonomic nervous system that responds to pain and stress. -the other branch is called the parasympathetic nervous system. -(think of the sympathetic branch as the responder when homeostasis needs restoring and the parasympathetic branch as the commander of function during normal times.) -both systems transmit their messages through the brain and spinal cord. -nerves of the two branches travel side by side along the same pathways to transmit their messages, but they oppose each other s actions (see figure a-3 on p. a-8). -an example will show how the sympathetic and parasympathetic nervous sys- tems work to maintain homeostasis. -when you go outside in cold weather, your skin s temperature receptors send cold messages to the spinal cord and brain. -your conscious mind may intervene at this point to tell you to zip your jacket, but let s say you have no jacket. -your sympathetic nervous system reacts to the exter- nal stressor, the cold. -it signals your skin-surface capillaries to shut down so that your blood will circulate deeper in your tissues, where it will conserve heat. -your sympathetic nervous system also signals involuntary contractions of the small muscles just under the skin surface. -the product of these muscle contractions is heat, and the visible result is goose bumps. -if these measures do not raise your body temperature enough, then the sympathetic nerves signal your large muscle groups cells, hormones, and nerves a-7 a a p p e n d i x g lossary of nervous system autonomic nervous system: the division of the nervous system that controls the body s automatic responses. -its two branches are the sympathetic branch, which helps the body respond to stressors from the outside environment, and the parasympathetic branch, which regulates normal body activities between stressful times. -autonomos (cid:2) self-governing central nervous system: the central part of the nervous system; the brain and spinal cord. -peripheral (puh-riff-er-ul) nervous system: the peripheral (outermost) part of the nervous system; the vast complex of wiring that extends from the central nervous system to the body s outermost areas. -it contains both somatic and autonomic components. -somatic (so-mat-ick) nervous system: the division of the nervous system that controls the voluntary muscles, as distinguished from the autonomic nervous system, which controls involuntary functions. -soma (cid:2) body a-8 appendix a figure a-3 the organization of the nervous system the brain and spinal cord evaluate information about conditions within and out- side the body, and the peripheral nerves receive information and send instructions. -brain spinal cord peripheral nerves physical structures, such as the brain and nerves, make up all the nervous system divisions. -they can be separated by function. -a x i d n e p p a somatic nervous system (conscious control of voluntary muscles) autonomic nervous system (automatic control of involuntary muscles and organs) sympathetic nervous system (responds to stressors) parasympathetic nervous system (regulates normal activities) to shiver; the contractions of these large muscles produce still more heat. -all of this activity helps to maintain your homeostasis (with respect to temperature) under conditions of external extremes (cold) that would throw it off balance. -the cold was a stressor; the body s response was resistance. -now let s say you come in and sit by a re and drink hot cocoa. -you are warm and no longer need all that sympathetic activity. -at this point, your parasympa- thetic nerves take over; they signal your skin-surface capillaries to dilate again, your goose bumps to subside, and your muscles to relax. -your body is back to nor- mal. -this is recovery. -putting it together the hormonal and nervous systems coordinate body functions by transmitting and receiving messages. -the point-to-point messages of the nervous system travel through a central switchboard (the spinal cord and brain), whereas the messages of the hormonal system are broadcast over the airways (the bloodstream), and any or- gan with the appropriate receptors can pick them up. -nerve impulses travel faster than hormonal messages do although both are remarkably swift. -whereas your brain s command to wiggle your toes reaches the toes within a fraction of a second and stops as quickly, a gland s message to alter a body condition may take several seconds or minutes to get started and may fade away equally slowly. -together, the two systems possess every characteristic a superb communication network needs: varied speeds of transmission, along with private communication lines or public broadcasting systems, depending on the needs of the moment. -the hormonal system, together with the nervous system, integrates the whole body s functioning so that all parts act smoothly together. -basic chemistry concepts this appendix is intended to provide the background in basic chemistry you need to understand the nutrition concepts pre- sented in this book. -chemistry is the branch of natural science that is concerned with the description and classi cation of matter, the changes that matter undergoes, and the energy associated with these changes. -the accompanying glossary de- nes matter, energy, and other related terms. -matter: the properties of atoms every substance has physical and chemical properties that distinguish it from all other substances and thus give it a unique identity. -the physical properties include such charac- teristics as color, taste, texture, and odor, as well as the tem- peratures at which a substance changes its state (from a solid to a liquid or from a liquid to a gas) and the weight of a unit volume (its density). -the chemical properties of a substance have to do with how it reacts with other substances or re- sponds to a change in its environment so that new substances with different sets of properties are produced. -a physical change does not change a substance s chemical composition. -the three physical states ice, water, and steam all consist of two hydrogen atoms and one oxygen atom bound together. -in contrast, a chemical change occurs when an electric current passes through water. -the water dis- appears, and two different substances are formed: hydrogen gas, which is ammable, and oxygen gas, which supports life. -substances: elements and compounds the smallest part of a substance that can exist separately with- out losing its physical and chemical properties is a molecule. -if a molecule is composed of atoms that are alike, the sub- stance is an element (for example, o2). -if a molecule is com- posed of two or more different kinds of atoms, the substance is a compound (for example, h2o). -just over 100 elements are known, and these are listed in table b-1. -a familiar example is hydrogen, whose molecules are composed only of hydrogen atoms linked together in pairs (h2). -on the other hand, over a million compounds are known. -an example is the sugar glucose. -each of its molecules is com- posed of 6 carbon, 6 oxygen, and 12 hydrogen atoms linked to- gether in a speci c arrangement (as described in chapter 4). -the nature of atoms atoms themselves are made of smaller particles. -within the atomic nucleus are protons (positively charged particles), and surrounding the nucleus are electrons (negatively charged par- ticles). -the number of protons ((cid:2)) in the nucleus of an atom de- basic chemistry concepts b-1 contents matter: the property of atoms chemical bonding formation of ions water, acids, and bases chemical reactions formation of free radicals g lossary atoms: the smallest components of an element that have all of the properties of the element. -compound: a substance composed of two or more different atoms for example, water (h2o). -element: a substance composed of atoms that are alike for example, iron (fe). -energy: the capacity to do work. -matter: anything that takes up space and has mass. -molecule: two or more atoms of the same or different elements joined by chemical bonds. -examples are molecules of the element oxygen, composed of two oxygen atoms (o2), and molecules of the compound water, composed of two hydrogen atoms and one oxygen atom (h2o). -b a p p e n d i x termines the number of electrons ((cid:3)) around it. -the positive charge on a proton is equal to the negative charge on an elec- tron, so the charges cancel each other out and leave the atom neutral to its surroundings. -the nucleus may also include neutrons, subatomic parti- cles that have no charge. -protons and neutrons are of equal mass, and together they give an atom its weight. -electrons bond atoms together to make molecules, and they are in- volved in chemical reactions. -each type of atom has a characteristic number of protons in its nucleus. -the hydrogen atom is the simplest of all. -it pos- sesses a single proton, with a single electron associated with it: + electron proton hydrogen atom (h), atomic number 1. just as hydrogen always has one proton, helium always has two, lithium three, and so on. -the atomic number of each ele- ment is the number of protons in the nucleus of that atom, and this never changes in a chemical reaction; it gives the atom its identity. -the atomic numbers for the known elements are listed in table b-1. -b-2 appendix b table b-1 chemical symbols for the elements key: elements found in energy-yielding nutrients, vitamins, and water major minerals trace minerals number of protons (atomic number) element number of electrons in outer shell number of protons (atomic number) element number of electrons in outer shell b x i d n e p p a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 hydrogen (h) helium (he) lithium (li) beryllium (be) boron (b) carbon (c) nitrogen (n) oxygen (o) fluorine (f) neon (ne) sodium (na) magnesium (mg) aluminum (al) silicon (si) phosphorus (p) sulfur (s) chlorine (cl) argon (ar) potassium (k) calcium (ca) scandium (sc) titanium (ti) vanadium (v) chromium (cr) manganese (mn) iron (fe) cobalt (co) nickel (ni) copper (cu) zinc (zn) gallium (ga) germanium (ge) arsenic (as) selenium (se) bromine (br) krypton (kr) rubidium (rb) strontium (sr) yttrium (y) zirconium (zr) niobium (nb) molybdenum (mo) technetium (tc) ruthenium (ru) rhodium (rh) palladium (pd) silver (ag) cadmium (cd) indium (in) tin (sn) antimony (sb) tellurium (te) iodine (i) xenon (xe) cesium (cs) barium (ba) 1 2 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 2 2 2 1 2 2 2 2 1 2 3 4 5 6 7 8 1 2 2 2 1 1 1 1 1 1 2 3 4 5 6 7 8 1 2 57 58 58 58 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 lanthanum (la) cerium (ce) cerium (ce) cerium (ce) neodymium (nd) promethium (pm) samarium (sm) europium (eu) gadolinium (gd) terbium (tb) dysprosium (dy) holmium (ho) erbium (er) thulium (tm) ytterbium (yb) lutetium (lu) hafnium (hf) tantalum (ta) tungsten (w) rhenium (re) osmium (os) iridium (ir) platinum (pt) gold (au) mercury (hg) thallium (tl) lead (pb) bismuth (bi) polonium (po) astatine (at) radon (rn) francium (fr) radium (ra) actinium (ac) thorium (th) protactinium (pa) uranium (u) neptunium (np) plutonium (pu) americium (am) curium (cm) berkelium (bk) californium (cf) einsteinium (es) fermium (fm) mendelevium (md) nobelium (no) lawrencium (lr) rutherfordium (rf) dubnium (db) seaborgium (sg) bohrium (bh) hassium (hs) meitnerium (mt) darmstadtium (ds) 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 2 3 4 5 6 7 8 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 besides hydrogen, the atoms most common in living things are carbon (c), nitrogen (n), and oxygen (o), whose atomic numbers are 6, 7, and 8, respectively. -their structures are more complicated than that of hydrogen, but each of them possesses the same number of electrons as there are protons in the nucleus. -these electrons are found in orbits, or shells (shown below). -6+ + + + + + + 7+ + + + ++ + + 8+ ++ ++ + + + + carbon atom (c), atomic number 6 nitrogen atom (n), atomic number 7 oxygen atom (o), atomic number 8 in these and all diagrams of atoms that follow, only the protons and elec- trons are shown. -the neutrons, which contribute only to atomic weight, not to charge, are omitted. -the most important structural feature of an atom for de- termining its chemical behavior is the number of electrons in its outermost shell. -the rst, or innermost, shell is full when it is occupied by two electrons; so an atom with two or more electrons has a lled rst shell. -when the rst shell is full, elec- trons begin to ll the second shell. -the second shell is completely full when it has eight elec- trons. -a substance that has a full outer shell tends not to enter into chemical reactions. -atomic number 10, neon, is a chemi- cally inert substance because its outer shell is complete. -fluo- rine, atomic number 9, has a great tendency to draw an electron from other substances to complete its outer shell, and thus it is highly reactive. -carbon has a half-full outer shell, which helps explain its great versatility; it can combine with other elements in a variety of ways to form a large number of compounds. -atoms seek to reach a state of maximum stability or of lowest energy in the same way that a ball will roll down a hill until it reaches the lowest place. -an atom achieves a state of maximum stability: by gaining or losing electrons to either ll or empty its outer shell. -by sharing its electrons with other atoms and thereby completing its outer shell. -the number of electrons determines how the atom will chem- ically react with other atoms. -the atomic number, not the weight, is what gives an atom its chemical nature. -chemical bonding atoms often complete their outer shells by sharing electrons with other atoms. -in order to complete its outer shell, a carbon atom requires four electrons. -a hydrogen atom requires one. -thus, when a carbon atom shares electrons with four hydro- gen atoms, each completes its outer shell (as shown in the next column). -electron sharing binds the atoms together and satis es the conditions of maximum stability for the mole- cule. -the outer shell of each atom is complete, since hydrogen effectively has the required two electrons in its rst (outer) basic chemistry concepts b-3 shell, and carbon has eight electrons in its second (outer) shell; and the molecule is electrically neutral, with a total of ten protons and ten electrons. -h + h + 6+ + + + + + + c + h + h when a carbon atom shares electrons with four hydrogen atoms, a methane molecule is made. -b a p p e n d i x + + 6+ + + + + + + + + the chemical formula for methane is ch4. -note that by sharing electrons, every atom achieves a lled outer shell. -bonds that involve the sharing of electrons, like the bonds between carbon and the four hydrogens, are the most stable kind of association that atoms can form with one another. -these bonds are called covalent bonds, and the resulting com- bination of atoms are called molecules. -a single pair of shared electrons forms a single bond. -a simpli ed way to rep- resent a single bond is with a single line. -thus the structure of methane (ch4) could be represented like this: h h c h h methane (ch4) similarly, one nitrogen atom and three hydrogen atoms can share electrons to form one molecule of ammonia (nh3): b-4 appendix b h + n 7+ + + + ++ + + + h + h 8+ ++ ++ + + + + o o 8+ ++ ++ + + + + oxygen molecule (o2) small atoms form the tightest, most stable bonds. -h, o, n, and c are the smallest atoms capable of forming one, two, three, and four electron-pair bonds respectively. -this is the ba- sis for the statement in chapter 4 that in drawings of com- pounds containing these atoms, hydrogen must always have one, oxygen two, nitrogen three, and carbon four bonds radi- ating to other atoms: when a nitrogen atom shares electrons with three hydrogen atoms, an ammonia molecule is made. -h o n c b x i d n e p p a + 7+ + + + ++ + + the stability of the associations between these small atoms and the versatility with which they can combine make them very common in living things. -interestingly, all cells, whether they come from animals, plants, or bacteria, contain the same elements in very nearly the same proportions. -the elements commonly found in living things are shown in table b-2. -+ + h n h h ammonia (nh3) the chemical formula for ammonia is nh3. -count the electrons in each atom s outer shell to con rm that it is lled. -table b-2 human body elemental composition of the one oxygen atom may be bonded to two hydrogen atoms to form one molecule of water (h2o): + + 8+ ++ + ++ ++ + water molecule (h2o) h h o element oxygen carbon hydrogen nitrogen calcium phosphorus potassium sulfur sodium chloride magnesium total chemical symbol by weight (%) o c h n ca p k s na cl mg 65 18 10 3 1.5 1.0 0.4 0.3 0.2 0.1 0.1 99.6a when two oxygen atoms form a molecule of oxygen, they must share two pairs of electrons. -this double bond may be represented as two single lines: athe remaining 0.40 percent by weight is contributed by the trace elements: chromium (cr), copper (cu), zinc (zn), selenium (se), molybdenum (mo), uorine (f), iodine (i), manganese (mn), and iron (fe). -cells may also contain variable traces of some of the following: boron (b), cobalt (co), lithium (li), strontium (sr), aluminum (al), silicon (si), lead (pb), vanadium (v), arsenic (as), bromine (br), and others. -formation of ions an atom such as sodium (na, atomic number 11) cannot eas- ily ll its outer shell by sharing. -sodium possesses a lled rst shell of two electrons and a lled second shell of eight; there is only one electron in its outermost shell: basic chemistry concepts b-5 a positively charged ion such as sodium ion (na(cid:2)) is called a cation; a negatively charged ion such as a chloride ion (cl(cid:3)) is called an anion. -cations and anions attract one another to form salts: + + + + + + + + + 11+ + + + + + + + + + + + + + 11+ sodium atom (na) 11 + charges 11 charges 0 net charge with one reactive electron in the outer shell loss of 1 electron sodium ion (na+) 11 + charges 10 charges 1 + net charge and a filled outer shell if sodium loses this electron, it satis es one condition for stabil- ity: a lled outer shell (now its second shell counts as the outer shell). -however, it is not electrically neutral. -it has 11 protons (positive) and only 10 electrons (negative). -it therefore has a net positive charge. -an atom or molecule that has lost or gained one or more electrons and so is electrically charged is called an ion. -an atom such as chlorine (cl, atomic number 17), with seven electrons in its outermost shell, can share electrons to ll its outer shell, or it can gain one electron to complete its outer shell and thus give it a negative charge: 17+ ++++ + + + + + + + + + + + + + 17+ ++++ + + ++ + + + + + + + + + chlorine atom (cl) 17 + charges 17 charges 0 net charge but lacks one electron to fill outer shell gain of 1 electron chloride ion (cl ) 17 + charges 18 charges 1 net charge and a filled outer shell + + + + + + + + + + + 11+ 17+ ++++ + + + + + + + + + + + + + sodium chloride (na+cl ) na+ 28 + charges 28 charges 0 net charge and filled outer shells cl b a p p e n d i x with all its electrons, sodium is a shiny, highly reactive metal; chlorine is the poisonous greenish yellow gas that was used in world war i. but after sodium and chlorine have transferred electrons, they form the stable white salt familiar to you as table salt, or sodium chloride (na(cid:2)cl(cid:3)). -the dramatic differ- ence illustrates how profoundly the electron arrangement can in uence the nature of a substance. -the wide distribution of salt in nature attests to the stability of the union between the ions. -each meets the other s needs (a good marriage). -when dry, salt exists as crystals; its ions are stacked very regularly into a lattice, with positive and negative ions alter- nating in a three-dimensional checkerboard structure. -in wa- ter, however, the salt quickly dissolves, and its ions separate from one another, forming an electrolyte solution in which they move about freely. -covalently bonded molecules rarely dissociate like this in a water solution. -the most common ex- ception is when they behave like acids and release h(cid:2) ions, as discussed in the next section. -an ion can also be a group of atoms bound together in such a way that the group has a net charge and enters into re- actions as a single unit. -many such groups are active in the uids of the body. -the bicarbonate ion is composed of ve atoms one h, one c, and three os and has a net charge of (cid:3)). -another important ion of this type is a phos- (cid:3)1 (hco3 phate ion with one h, one p, and four o, and a net charge of (cid:3)2 (hpo4 (cid:3)2). -whereas many elements have only one con guration in the outer shell and thus only one way to bond with other ele- ments, some elements have the possibility of varied con gura- tions. -iron is such an element. -under some conditions iron loses two electrons, and under other circumstances it loses b-6 appendix b three. -if iron loses two electrons, it then has a net charge of (cid:2)2, and we call it ferrous iron (fe(cid:2)(cid:2)). -if it donates three electrons to another atom, it becomes the (cid:2)3 ion, or ferric iron (fe(cid:2)(cid:2)(cid:2)). -ferrous iron (fe(cid:2)(cid:2)) (had 2 outer-shell electrons but has lost them) 26 (cid:2) charges 24 (cid:3) charges 2 (cid:2) net charge ferric iron (fe(cid:2)(cid:2)(cid:2)) (had 3 outer-shell electrons but has lost them) 26 (cid:2) charges 23 (cid:3) charges 3 (cid:2) net charge remember that a positive charge on an ion means that nega- tive charges electrons have been lost and not that positive charges have been added to the nucleus. -b x i d n e p p a water, acids, and bases water the water molecule is electrically neutral, having equal num- bers of protons and electrons. -when a hydrogen atom shares its electron with oxygen, however, that electron will spend most of its time closer to the positively charged oxygen nucleus. -this leaves the positive proton (nucleus of the hydrogen atom) ex- posed on the outer part of the water molecule. -we know, too, that the two hydrogens both bond toward the same side of the oxygen. -these two facts explain why water molecules are polar: they have regions of more positive and more negative charge. -polar molecules like water are drawn to one another by the attractive forces between the positive polar areas of one and the negative poles of another. -these attractive forces, some- times known as polar bonds or hydrogen bonds, occur among many molecules and also within the different parts of single large molecules. -although very weak in comparison with co- valent bonds, polar bonds may occur in such abundance that they become exceedingly important in determining the struc- ture of such large molecules as proteins and dna. -+ h ho + this diagram of the polar water molecule shows displacement of electrons toward the o nucleus; thus the negative region is near the o and the posi- tive regions are near the h atoms. -acetic acid is also an acid because it dissociates in water to ac- etate ions and free h(cid:2): oh oh c o h h h c h c o + h+ c h acetic acid dissociates into an acetate ion and a hydrogen ion. -the more h(cid:2) ions released, the stronger the acid. -ph chemists de ne degrees of acidity by means of the ph scale, which runs from 0 to 14. the ph expresses the concentration of h(cid:2) ions: a ph of 1 is extremely acidic, 7 is neutral, and 13 is very basic. -there is a tenfold difference in the concentration of h(cid:2) ions between points on this scale. -a solution with ph 3, for ex- ample, has ten times as many h(cid:2) ions as a solution with ph 4. at ph 7, the concentrations of free h(cid:2) and oh(cid:3) are exactly the same 1/10,000,000 moles per liter (1027 moles per liter). -* at ph 4, the concentration of free h(cid:2) ions is 1/10,000 (1024) moles per liter. -this is a higher concentration of h(cid:2) ions, and the solu- tion is therefore acidic. -figure 3-6 on p. 77 presents the ph scale. -bases a base is a substance that can combine with h+ ions, thus re- ducing the acidity of a solution. -the compound ammonia is such a substance. -the ammonia molecule has two electrons that are not shared with any other atom; a hydrogen ion (h(cid:2)) is just a naked proton with no shell of electrons at all. -the pro- ton readily combines with the ammonia molecule to form an ammonium ion; thus a free proton is withdrawn from the solu- tion and no longer contributes to its acidity. -many compounds containing nitrogen are important bases in living systems. -acids and bases neutralize each other to produce substances that are neither acid nor base. -h h . -h +. -n h+ h n+ h h h ammonia captures a hydrogen ion from water. -the two dots here represent the two electrons not shared with another atom. -these dots are ordinarily not shown in chemical structure drawings. -compare this drawing with the earlier diagram of an ammonia molecule (p. b-4). -water molecules have a slight tendency to ionize, separat- ing into positive (h(cid:2)) and negative (oh(cid:3)) ions. -in pure water, a small but constant number of these ions is present, and the number of positive ions exactly equals the number of neg- ative ions. -acid an acid is a substance that releases h(cid:2) ions (protons) in a wa- ter solution. -hydrochloric acid (hcl(cid:3)) is such a substance be- cause it dissociates in a water solution into h(cid:2) and cl(cid:3) ions. -chemical reactions a chemical reaction, or chemical change, results in the break- down of substances and the formation of new ones. -almost all such reactions involve a change in the bonding of atoms. -old bonds are broken, and new ones are formed. -the nuclei of atoms are never involved in chemical reactions only their *a mole is a certain number (about 6 (cid:4) 1023) of molecules. -the ph of a solu- tion is de ned as the negative logarithm of the hydrogen ion concentration of the solution. -thus, if the concentration is 10(cid:3)2 (moles per liter), the ph is 2; if 10(cid:3)8, the ph is 8; and so on. -diagrams: + + + + 8+ ++ ++ + + + + 8+ ++ ++ + + + + 2 hydrogen molecules 1 oxygen molecule + + 8+ ++ ++ + + + + + + 8+ ++ ++ + + + + 2 water molecules structures: h h + h h + oo h o h + oh h formulas: 2h2 + o2 2h2o hydrogen and oxygen react to form water. -outer-shell electrons take part. -at the end of a chemical reaction, the number of atoms of each type is always the same as at the beginning. -for example, two hydrogen molecules (2h2) can re- act with one oxygen molecule (o2) to form two water molecules (2h2o). -in this reaction two substances (hydrogen and oxygen) disappear, and a new one (water) is formed, but at the end of the reaction there are still four h atoms and two o atoms, just as there were at the beginning. -because the atoms are now linked in a different way, their characteristics or properties have changed. -in many instances chemical reactions involve not the re- linking of molecules but the exchanging of electrons or pro- tons among them. -in such reactions the molecule that gains one or more electrons (or loses one or more hydrogen ions) is said to be reduced; the molecule that loses electrons (or gains basic chemistry concepts b-7 protons) is oxidized. -a hydrogen ion is equivalent to a proton. -oxidation and reduction reactions take place simultaneously because an electron or proton that is lost by one molecule is ac- cepted by another. -the addition of an atom of oxygen is also oxidation because oxygen (with six electrons in the outer shell) accepts two electrons in becoming bonded. -oxidation, then, is loss of electrons, gain of protons, or addition of oxygen (with six electrons); reduction is the opposite gain of elec- trons, loss of protons, or loss of oxygen. -the addition of hydro- gen atoms to oxygen to form water can thus be described as the reduction of oxygen or the oxidation of hydrogen. -if a reaction results in a net increase in the energy of a compound, it is called an endergonic, or uphill, reaction (energy, erg, is added into, endo, the compound). -an example is the chief result of photosynthesis, the making of sugar in a plant from carbon dioxide and water using the energy of sun- light. -conversely, the oxidation of sugar to carbon dioxide and water is an exergonic, or downhill, reaction because the end products have less energy than the starting products. -oftentimes, but not always, reduction reactions are ender- gonic, resulting in an increase in the energy of the products. -oxidation reactions often, but not always, are exergonic. -chemical reactions tend to occur spontaneously if the end products are in a lower energy state and therefore are more stable than the reacting compounds. -these reactions often give off energy in the form of heat as they occur. -the genera- tion of heat by wood burning in a replace and the mainte- nance of human body warmth both depend on energy- yielding chemical reactions. -these downhill reactions occur easily, although they may require some activation energy to get them started, just as a ball requires a push to start rolling. -uphill reactions, in which the products contain more en- ergy than the reacting compounds started with, do not occur until an energy source is provided. -an example of such an en- ergy source is the sunlight used in photosynthesis, where car- bon dioxide and water (low-energy compounds) are combined to form the sugar glucose (a higher-energy compound). -an- other example is the use of the energy in glucose to combine two low-energy compounds in the body into the high-energy energy change as reaction occurs 2h2 + o2 activation energy b a p p e n d i x energy release start of reaction reactants 2h2 + o2 2h2o end of reaction products 2h2o oxidation of some compounds can be induced by air at room temperature in the presence of light. -such reactions are thought to take place through the formation of compounds called peroxides: peroxides: h o o h hydrogen peroxide r o o h hydroperoxides (r is any carbon chain with appropriate numbers of h) r o o r peroxide some peroxides readily disintegrate into free radicals, initiat- ing chain reactions like those just described. -free radicals are of special interest in nutrition because the antioxidant properties of vitamins c and e as well as beta- carotene and the mineral selenium are thought to protect against the destructive effects of these free radicals (see high- light 11). -for example, vitamin e on the surface of the lungs reacts with, and is destroyed by, free radicals, thus preventing the radicals from reaching underlying cells and oxidizing the lipids in their membranes. -b x i d n e p p a b-8 appendix b compound atp (see chapter 7). -the energy in atp may be used to power many other energy-requiring, uphill reactions. -clearly, any of many different molecules can be used as a tem- porary storage place for energy. -neither downhill nor uphill reactions occur until some- thing sets them off (activation) or until a path is provided for them to follow. -the body uses enzymes as a means of provid- ing paths and controlling chemical reactions (see chapter 6). -by controlling the availability and the action of its enzymes, the cells can decide which chemical reactions to prevent and which to promote. -formation of free radicals normally, when a chemical reaction takes place, bonds break and re-form with some redistribution of atoms and rearrange- ment of bonds to form new, stable compounds. -normally, bonds don t split in such a way as to leave a molecule with an odd, unpaired electron. -when they do, free radicals are formed. -free radicals are highly unstable and quickly react with other compounds, forming more free radicals in a chain reaction. -a cascade may ensue in which many highly reactive radicals are generated, resulting nally in the disruption of a living structure such as a cell membrane. -heat or light h o + o h or r o + o h free radical h o o h or r o o h hydrogen peroxide or any hydroperoxide (r is any carbon chain with appropriate numbers of h) free radicals are formed. -the dots represent single electrons that are available for sharing (the atom needs another electron to fill its outer shell). -h h h o + h c h h o h + h c h or r h free radical compound with weak bond (perhaps an unsaturated fatty acid) new stable compound (water or an alcohol) h or r free radical free radicals destroy biological compounds. -the free radical attacks a weak bond in a biological compound, disrupting it and forming a new stable molecule and another free radical. -this free radical can attack another biological compound, and so on. -biochemical structures and pathways c-1 biochemical structures and pathways the diagrams of nutrients presented here are meant to en- hance your understanding of the most important organic molecules in the human diet. -following the diagrams of nu- trients are sections on the major metabolic pathways men- tioned in chapter 7 glycolysis, fatty acid oxidation, amino acid degradation, the tca cycle, and the electron transport chain and a description of how alcohol interferes with these pathways. -discussions of the urea cycle and the formation of ketone bodies complete the appendix. -contents carbohydrates lipids protein: amino acids vitamins and coenzymes glycolysis fatty acid oxidation amino acid degradation the tca cycle the electron transport chain alcohol s interference with energy metabolism the urea cycle formation of ketone bodies carbohydrates monosaccharides h 6 h c 4 oh h c c h o c h o h 5 h 3 o h c 2 h c 1 o h o h glucose (alpha form). -the ring would be at right angles to the plane of the paper. -the bonds directed upward are above the plane; those directed downward are below the plane. -this molecule is considered an alpha form because the oh on carbon 1 points downward. -disaccharides ch2oh o oh h h ch2oh o oh ho oh o oh oh glucose glucose maltose. -h h c oh h c c h o c h o h h o h c h o h c o h ch2oh o oh ho oh oh glucose (beta form). -the oh on carbon 1 points upward. -fructose, galactose: see chapter 4. glucose (alpha form) shorthand notation. -this notation, in which the carbons in the ring and single hydrogens have been eliminated, will be used throughout this appendix. -c a p p e n d i x h o ch2oh o oh oh oh ho ch2oh o oh h oh glucose galactose lactose (alpha form). -ch2oh oh ho ch2oh o ho h o oh oh glucose fructose sucrose. -ch2oh c-2 appendix c polysaccharides as described in chapter 4, starch, glycogen, and cellulose are all long chains of glu- cose molecules covalently linked together. -ch2oh o oh ch2oh o ch2oh o ch2oh o 1 4 oh 1 4 1 4 oh 1 4 oh (etc.) -oh o oh o oh o o oh (etc.) -4 o amylose (unbranched starch) ch2oh o oh ch2oh o oh 1 oh o oh o (etc.) -o ch2oh o oh ch2oh o oh 6 ch2 o oh ch2oh o oh oh o oh o oh o oh 1 o (etc.) -o starch. -two kinds of covalent linkages occur between glucose molecules in starch, giving rise to two kinds of chains. -amylose is com- posed of straight chains, with carbon 1 of one glucose linked to carbon 4 of the next ((cid:2)-1,4 linkage). -amylopectin is made up of straight chains like amylose but has occasional branches arising where the carbon 6 of a glu- cose is also linked to the carbon 1 of another glucose ((cid:2)-1,6 linkage). -glycogen. -the structure of glycogen is like amylopectin but with many more branches. -cellulose. -like starch and glycogen, cellulose is also made of chains of glucose units, but there is an important difference: in cellulose, the oh on carbon 1 is in the beta position (see p. c-1). -when carbon 1 of one glucose is linked to carbon 4 of the next, it forms a -1,4 linkage, which cannot be broken by digestive enzymes in the human gi tract. -c x i d n e p p a (etc.) -o ch2oh o oh ch2oh o oh ch2oh o oh 6 ch2 o oh ch2oh o oh (etc.) -oh o oh o oh o oh o o oh amylopectin (branched starch) fibers, such as hemicelluloses, consist of long chains of various monosaccharides. -monosaccharides common in the backbone chain of hemicelluloses: h h oh h ho o h h* oh h oh xylose ch2oh ch2oh h ho h oh o oh h* oh h h mannose ho h h oh o h h* oh h oh galactose *these structures are shown in the alpha form with the h on the carbon pointing upward and the oh pointing downward, but they may also appear in the beta form with the h pointing downward and the oh upward. -biochemical structures and pathways c-3 monosaccharides common in the side chains of hemicelluloses: h h oh ho h o h h* oh h oh arabinose co2h h oh o h h* oh h ch3o h oh glucuronic acid ch2oh ho h h oh o h h* oh h oh galactose hemicelluloses. -the most common hemicelluloses are composed of a backbone chain of xylose, man- nose, and galactose, with branching side chains of arabinose, glucuronic acid, and galactose. -lipids table c-1 saturated fatty acids found in natural fats saturated fatty acids butyric caproic caprylic capric lauric myristica palmitica stearica arachidic behenic lignoceric chemical formulas c3h7cooh c5h11cooh c7h15cooh c9h19cooh c11h23cooh c13h27cooh c15h31cooh c17h35cooh c19h39cooh c21h43cooh c23h47cooh amost common saturated fatty acids. -number of carbons major food sources 4 6 8 10 12 14 16 18 20 22 24 butterfat butterfat coconut oil palm oil coconut oil, palm oil coconut oil, palm oil palm oil most animal fats peanut oil seeds peanut oil c a p p e n d i x table c-2 unsaturated fatty acids found in natural fats unsaturated fatty acids palmitoleic oleic linoleic linolenic arachidonic eicosapentaenoic docosahexaenoic chemical formulas c15h29cooh c17h33cooh c17h31cooh c17h29cooh c19h31cooh c19h29cooh c21h31cooh number of carbons number of double bonds 16 18 18 18 20 20 22 1 1 2 3 4 5 6 standard notationa 16:1;9 18:1;9 18:2;9,12 18:3;9,12,15 20:4;5,8,11,14 20:5;5,8,11,14,17 22:6;4,7,10,13,16,19 omega notationb 16:1 7 18:1 9 18:2 6 18:3 3 20:4 6 20:5 3 22:6 3 major food sources seafood, beef olive oil, canola oil sun ower oil, saf ower oil soybean oil, canola oil eggs, most animal fats seafood seafood note: a fatty acid has two ends; designated the methyl (ch3) end and the carboxyl, or acid (cooh), end. -astandard chemistry notation begins counting carbons at the acid end. -the number of carbons the fatty acid contains comes rst, followed by a colon and another number that indicates the number of double bonds; next comes a semicolon followed by a number or numbers indicating the positions of the double bonds. -thus the notation for linoleic acid, an 18-carbon fatty acid with two double bonds between carbons 9 and 10 and between carbons 12 and 13, is 18:2;9,12. bbecause fatty acid chains are lengthened by adding carbons at the acid end of the chain, chemists use the omega system of notation to ease the task of identifying them. -the omega system begins counting carbons at the methyl end. -the number of carbons the fatty acid contains comes rst, followed by a colon and the number of double bonds; next come the omega symbol ( ) and a number indicating the position of the double bond nearest the methyl end. -thus linoleic acid with its rst double bond at the sixth carbon from the methyl end would be noted 18:2 6 in the omega system. -protein: amino acids the common amino acids may be classi ed into the seven groups listed on the next page. -amino acids marked with an asterisk (*) are essential. -c-4 appendix c 1. amino acids with aliphatic side chains, which consist 4. amino acids with basic side chains: of hydrogen and carbon atoms (hydrocarbons): glycine (gly) nh2 ch2 ch2 ch2 ch2 c c oh h o nh2 lysine* (lys) h o h c c oh nh2 h o h3c c c oh alanine (ala) h3c h3c h3c h3c nh2 h o ch c c oh valine* (val) nh2 h o ch ch2 c c oh leucine* (leu) nh2 h o nh2 c nh ch2 ch2 nh h o ch2 c c oh nh2 arginine (arg) h o c c oh nh2 h c c ch2 n n h c h histidine* (his) h3c ch2 ch c c oh isoleucine* (ile) 5. amino acids with aromatic side chains, which are characterized by the presence of at least one ring structure: c x i d n e p p a ch3 nh2 2. amino acids with hydroxyl (oh) side chains: h o ho ch2 c c oh serine (ser) nh2 h o h3c ch c c oh threonine* (thr) oh nh2 3. amino acids with side chains containing acidic groups or their amides, which contain the group nh2: o h o ho c ch2 c c oh aspartic acid (asp) nh2 h o ch2 ch2 c c oh glutamic acid (glu) o c ho nh2 h o nh2 c ch2 o c c oh asparagine (asn) nh2 h o nh2 c o ch2 ch2 c c oh glutamine (gln) nh2 h c h h h c c c c c h h ho c c c c c h o ch2 c c oh nh2 h c h h o ch2 c c oh nh2 h h c c h h h c c h o c c c c ch2 c c oh nh2 h n h phenylalanine* (phe) tyrosine (tyr) tryptophan* (trp) 6. amino acids with side chains containing sulfur atoms: h o h o hs ch2 c c oh ch3 s ch2 ch2 c c oh nh2 cysteine (cys) nh2 methionine* (met) 7. imino acid: h h h c c h c n h h h c h o c oh proline (pro) proline has the same chemical structure as the other amino acids, but its amino group has given up a hydrogen to form a ring. -vitamins and coenzymes ch3 c ch ch ch h3c h h c h h c h c c ch3 ch ch ch3 c c h ch3 c c oh ch h h vitamin a: retinol. -this molecule is the alcohol form of vitamin a. ch3 c ch ch3 c ch o c h ch ch h3c h h c h h c h c c ch3 ch ch ch3 c c h vitamin a: retinal. -this molecule is the aldehyde form of vitamin a. ch3 c ch ch ch3 c ch o c oh ch ch h3c h h c h h c h c c ch3 ch c c h ch3 vitamin a: retinoic acid. -this molecule is the acid form of vitamin a. ch3 c ch ch3 c ch ch ch ch ch3 c ch ch3 c ch ch ch ch h3c h h c h h c h h3c h h c h h c h c c c c ch3 ch ch ch3 c c h ch3 ch ch ch3 c c h vitamin a precursor: beta-carotene. -this molecule is the carotenoid with the most vitamin a activity. -pyrophosphate oh oh oh oh oh h ch2 ch ch ch ch2 o p o p o c h o o h3c h3c c c h c c h c c n n c c c n o h n c o riboflavin h c h ho c o h c oh biochemical structures and pathways c-5 nh2 n c c n c c ch3 + c ch2 n h c h c s h3c ch2 ch2 oh thiamin. -this molecule is part of the coenzyme thiamin pyrophosphate (tpp). -nh2 c c c n n c ch3 + c ch2 n h c h c s h3c o o ch2 ch2 o p o p oh oh oh thiamin pyrophosphate (tpp). -tpp is a coenzyme that includes the thiamin molecule as part of its structure. -oh oh oh h3c h3c c c h c c h c c ch2 ch ch ch ch2 oh n o n c c n h c n c o riboflavin. -this molecule is a part of two coenzymes flavin mononucleotide (fmn) and flavin adenine dinucleotide (fad). -oh oh oh o c a p p e n d i x h3c h3c c c h c c h c c ch2 ch ch ch ch2 n o n c c o p oh oh n h c n c o flavin mononucleotide (fmn). -fmn is a coenzyme that includes the riboflavin molecule as part of its structure. -nh2 c n c n adenine ch n n c c c h fad can pick up hydrogens and carry them to the electron transport chain. -n c c h n becomes h n c c n h flavin adenine dinucleotide (fad). -fad is a coenzyme that includes the riboflavin molecule as part of its structure. -d-ribose fad (oxidized form) fadh2 (reduced form) c-6 appendix c c x i d n e p p a h c n o c h c c h h c c oh h c n o c h c c h h c c nh2 nicotinic acid nicotinamide niacin (nicotinic acid and nicotinamide). -these molecules are a part of two coenzymes nicotinamide adenine dinucleotide (nad+) and nicotinamide adenine dinucleotide phosphate (nadp+). -nicotinamide h c + n o c h c c h h c c nh2 h o d-ribose ho c ho c c h h c h adenine h c n n c c nh2 c n c n h h o c h h c h c oh c oh d-ribose o o ch2 o p o p o oh oh ch2 pyrophosphate nicotinamide adenine dinucleotide (nad+) and nicotinamide adenine dinucleotide phosphate (nadp+). -nadp has the same structure as nad but with a phosphate group attached to the o instead of the h . -h h h c + n o c h c c h h c c nh2 h+ h h h h c c c n c c o c h nh2 nad+ nadh reduced nad+ (nadh). -when nad+ is reduced by the addition of h+ and two electrons, it becomes the coenzyme nadh. -(the dots on the h entering this reaction represent electrons see appendix b.) -ch2 c c c n c c ho h3c oh ch2 oh h h c c n o c c ho h3c c c ch2 oh h ch2 c c c n c c ho h3c nh2 ch2 oh h pyridoxine pyridoxal pyridoxamine vitamin b6 (a general name for three compounds pyridoxine, pyridoxal, and pyridoxamine). -these molecules are a part of two coenzymes pyridoxal phosphate and pyridoxamine phosphate. -biochemical structures and pathways c-7 h c o ho h3c c c c n c c o ch2 o p oh oh h nh3 o nh3 ho c c o h3c ch2 nh2 c c ch2 c h n o o p oh oh pyridoxal phosphate pyridoxamine phosphate pyridoxal phosphate (plp) and pyridoxamine phosphate. -these coenzymes include vitamin b6 as part of their structures. -o c nh2 ch2 ch2 h c o c o c h2c h3c h3c h2c h2n h2n ch3 o h3c ch2 c nh2 o n n co+ n n ch2 ch2 c h nh2 h ch3 ch3 o h ch2 ch2 c nh2 h h2c ch3 ch2 c o ch3 ch2 nh ch3 ch o o p o o c h h c ch2 oh h n c c c n oh c h c o h h c c h c c ch3 ch3 oh c n c c n n n c c c h h c c ch2 n c h c c h h c h o c n h h2n o oh h c c ch2 ch2 cc o oh folate (folacin or folic acid). -this molecule consists of a double ring combined with a single ring and at least one glutamate (a nonessential amino acid marked in the box). -folate s biologically active form is tetrahydrofolate. -oh c n c c n c h n n h h2n h h ch2 n h h c c h c h c c c c h c h o c n h o oh h c c ch2 ch2 cc o oh c a p p e n d i x vitamin b12 (cyanocobalamin). -the arrows in this diagram indicate that the spare electron pairs on the nitrogens attract them to the cobalt. -tetrahydrofolate. -this active coenzyme form of folate has four added hydrogens. -an intermediate form, dihydrofolate, has two added hydrogens. -o c ho o oh ch2 ch2 n c ch ch3 c ch2 oh h ch3 pantothenic acid. -this molecule is part of coenzyme a (coa). -nh2 c n c c n n n c h c h h hs ch2 ch2 n o c o oh ch2 ch2 n c ch ch3 c ch2 o o p o po o ch2 h ch3 oh oh c h o h h cc o oh c h ho p o oh coenzyme a (coa). -coenzyme a is a coenzyme that includes pantothenic acid as part of its structure. -c-8 appendix c o c n n h h h c h h c c h h ch2 c s biotin. -o ch2 ch2 ch2 c oh o c o ch ho ho c c ho ch ch2oh 2h+ 2h+ o c o ch o o c c ho ch ch2oh ascorbic acid (reduced form) dehydroascorbic acid (oxidized form) vitamin c. two hydrogen atoms with their electrons are lost when ascorbic acid is oxidized and gained when it is reduced again. -c x i d n e p p a 7-dehydrocholesterol h3c ch3 1 ch3 2 ho 3 5 6 4 8 c carbon #7 ultraviolet light on the skin ch3 ch3 25 vitamin d3 (also called cholecalciterol or calciol) ch2 h3c ch3 ch3 ch3 ho hydroxylation in the liver h3c ch3 c ch3 oh ch3 carbon #25 25-hydroxy-vitamin d3 (also called calcidiol) ch2 hydroxylation in the kidneys ho c ch3 oh ch3 h3c ch3 ch2 1,25-dihydroxy-vitamin d3 (also called calcitrol) ho c oh carbon #1 vitamin d. the synthesis of active vitamin d begins with 7-dehydrocholesterol. -(the carbon atoms at which changes occur are numbered.) -biochemical structures and pathways c-9 ch3 h c c c o h c c c c c c ho h3c ch3 h ch3 h ch2 ch2 ch2 ch ch2 ch2 ch2 ch3 ch3 ch ch2 ch2 ch2 ch3 ch ch3 tocotrienols contain double bonds here. -vitamin e (alpha-tocopherol). -the number and position of the methyl groups (ch3) bonded to the ring structure differentiate among the tocopherols. -h h c c h c c h c c o c c o c c ch3 ch3 ch2 ch c ch2 ch2 ch2 ch3 ch ch2 ch2 ch2 ch3 ch ch2 ch2 ch2 ch3 ch ch3 vitamin k. naturally occurring compounds with vitamin k activity include phylloquinones (from plants) and menaquinones (from bacteria). -c a p p e n d i x h h c c h c c h c c o c c o c c ch3 h menadione. -this synthetic compound has the same activity as natural vitamin k. oh ho p o cleavage o triphosphate ho p o o h c ho p o nh2 c n c h n n n c c adenine ribose o ch2 c h o h h cc oh oh c h oh ho p o cleavage o ho p o o + h o h (water) adenosine triphosphate (atp), the energy carrier. -the cleavage point marks the bond that is broken when atp splits to become adp + p. adenosine diphosphate (adp). -h+ ho oh p o o phosphate + oh ho p o adp c-10 appendix c glycolysis figure c-1 depicts the events of glycolysis. -the following text describes key steps as numbered on the gure. -figure c-1 glycolysis notice that galactose and fructose enter at different places but continue on the same pathway. -glycogen galactose glucose-1-phosphate glucose 1 atp adp glucose-6-phosphate 2 fructose fructose-6-phosphate 3 atp adp fructose-1, 6-diphosphate 4 c x i d n e p p a dihydroxy acetone phosphate glyceraldehyde-3- phosphate glycerol 5 2nad+ 2nadh + 2h+ 1. a phosphate is attached to glucose at the carbon that chemists call number 6 (review the rst diagram of glucose on p. c-1 to see how chemists number the carbons in a glucose molecule). -the product is called, logically enough, glucose-6- phosphate. -one atp molecule is used to accomplish this. -2. glucose-6-phosphate is rearranged by an enzyme. -3. a phosphate is added in another reaction that uses another molecule of atp. -the product this time is fructose-1,6- diphosphate. -at this point the six-carbon sugar has a phos- phate group on its rst and sixth carbons and is ready to break apart. -4. when fructose-1,6-diphosphate breaks in half, the two three-carbon compounds are not identical. -each has a phos- phate group attached, but only glyceraldehyde-3-phosphate converts directly to pyruvate. -the other compound, how- ever, converts easily to glyceraldehyde-3-phosphate. -1,3-diphosphoglyceric acid 6 2adp 2atp 3-phosphoglyceric acid 2-phosphoglyceric acid phosphoenol pyruvic acid 6 2adp 2atp pyruvate lactate 2nadh + 2h+ 2nad+ 5. in the next step, enough energy is released to convert nad(cid:3) to nadh (cid:3) h(cid:3). -6. in two of the following steps atp is regenerated. -remember that in effect two molecules of glyceraldehyde-3- phosphate are produced from glucose; therefore, four atp mole- cules are generated from each glucose molecule. -two atp were needed to get the sequence started, so the net gain at this point is two atp and two molecules of nadh (cid:3) h(cid:3). -as you will see later, each nadh (cid:3) h(cid:3) moves to the electron transport chain to unload its hydrogens onto oxygen, producing more atp. -fatty acid oxidation figure c-2 presents fatty acid oxidation. -the sequence is as follows. -1. the fatty acid is activated by combining with coenzyme a (coa). -in this reaction, atp loses two phosphorus atoms (pp, or pyrophosphate) and becomes amp (adenosine monophosphate) the equivalent of a loss of two atp. -2. in the next reaction, two h with their electrons are re- moved and transferred to fad, forming fadh2. -figure c-2 fatty acid oxidation palmitic acid (16c) coa 1 atp amp + pp activated palmitic acid 2 3 fad fadh2 h2o nad+ nadh + h+ 5 coa 4 activated myristic acid (14c) + acetyl coa (2c) biochemical structures and pathways c-11 3. in a later reaction, two h are removed and go to nad(cid:3) (forming nadh (cid:3) h(cid:3)). -4. the fatty acid is cleaved at the beta carbon, the second carbon from the carboxyl (cooh) end. -this break results in a fatty acid that is two carbons shorter than the previous one and a two-carbon molecule of acetyl coa. -at the same time, another coa is attached to the fatty acid, thus acti- vating it for its turn through the series of reactions. -5. the sequence is repeated with each cycle producing an acetyl coa and a shorter fatty acid until only a 2-carbon fatty acid remains acetyl coa. -in the example shown in figure c-2, palmitic acid (a 16- carbon fatty acid) will go through this series of reactions seven times, using the equivalent of two atp for the initial activa- tion and generating seven fadh2, seven nadh (cid:3) h(cid:3), and eight acetyl coa. -as you will see later, each of the seven fadh2 will enter the electron transport chain to unload its hydrogens onto oxygen, yielding two atp (for a total of 14). -similarly, each nadh (cid:3) h(cid:3) will enter the electron transport chain to unload its hydrogens onto oxygen, yielding three atp (for a total of 21). -thus the oxidation of a 16-carbon fatty acid uses 2 atp and generates 35 atp. -when the eight acetyl coa enter the tca cycle, even more atp will be generated, as a later section describes. -amino acid degradation the rst step in amino acid degradation is the removal of the nitrogen-containing amino group through either deamination (figure 7-14 on p. 226) or transamination (figure 7-15 on p. 226) reactions. -then the remaining carbon skeletons may enter the metabolic pathways at different places, as shown in figure c-3. -c a p p e n d i x the tca cycle the tricarboxylic acid, or tca, cycle is the set of reactions that break down acetyl coa to carbon dioxide and hydrogens. -to link glycolysis to the tca cycle, pyruvate enters the mito- chondrion, loses a carbon group, and bonds with a molecule of coa to become acetyl coa. -the tca cycle uses any sub- stance that can be converted to acetyl coa directly or indi- rectly through pyruvate. -glucose glycerol some amino acids pyruvate lactate some amino acids acetyl coa fatty acids some amino acids tca the step from pyruvate to acetyl coa is complex. -we have included only those substances that will help you understand c-12 appendix c figure c-3 amino acid degradation after losing their amino groups, carbon skeletons can be converted to one of seven molecules that can enter the tca cycle (presented in figure c-4). -isoleucine leucine lysine tryptophan asparagine aspartate oxaloacetate malate pyruvate alanine cysteine glysine serine tryptophan threonine acetyl coa acetoacetyl coa leucine phenylalanine tyrosine citrate tca cycle isocitrate aspartate phenylalanine tyrosine fumarate succinate c x i d n e p p a the step from pyruvate to acetyl coa. -(tpp and nad are coenzymes containing the b vitamins thiamin and niacin, respectively.) -alpha-ketoglutarate arginine glutamate glutamine histidine lysine proline succinyl coa isoleucine methionine threonine valine the transfer of energy from the nutrients. -pyruvate loses a car- bon to carbon dioxide and is attached to a molecule of coa. -in the process, nad(cid:3) picks up two hydrogens with their asso- ciated electrons, becoming nadh (cid:3) h(cid:3). -let s follow the steps of the tca cycle (see the correspon- ding numbers in figure c-4). -1. the two-carbon acetyl coa combines with a four-carbon compound, oxaloacetate. -the coa comes off, and the product is a six-carbon compound, citrate. -2. the atoms of citrate are rearranged to form isocitrate. -3. now two h (with their two electrons) are removed from the isocitrate. -one h becomes attached to the nad(cid:3) with the two electrons; the other h is released as h(cid:3). -thus nad(cid:3) be- comes nadh (cid:3) h(cid:3). -(remember this nadh (cid:3) h(cid:3), but let s follow the carbons rst.) -a carbon is combined with two oxygens, forming carbon dioxide (which diffuses away into the blood and is exhaled). -what is left is the ve-carbon compound alpha-ketoglutarate. -figure c-4 the tca cycle biochemical structures and pathways c-13 with the assistance of a biotin coenzyme, pyruvate receives a carbon from carbon dioxide to regenerate oxaloacetate. -this reaction is energetically costly. -cooh c o ch2 cooh oxaloacetate nadh + h+ nad+ 8 cooh c o ch3 pyruvate coa nad+ nadh + h+ co2 tpp o h3c c (coa) acetyl coa 1 coa cooh ch2 c cooh ho ch2 cooh citrate cooh h c oh ch2 cooh malate h2o 7 cooh ch ch cooh fumarate fadh2 fad 6 cooh ch2 ch2 cooh succinate h2o h2o 2 cooh ch2 c cooh c oh cooh h h isocitrate 3 nad+ nadh + h+ co2 cooh ch2 ch2 o c cooh c a p p e n d i x 5 cooh 4 coa gtp gdp + p ch2 ch2 c (coa) o h2o succinyl coa alpha- ketoglutarate coa nad+ nadh + h+ co2 4. now two compounds interact with alpha-ketoglutarate a molecule of coa and a molecule of nad(cid:3). -in this complex reaction, a carbon and two oxygens are removed (forming carbon dioxide); two hydrogens are removed and go to nad(cid:3) (forming nadh (cid:3) h(cid:3)); and the remaining four- carbon compound is attached to the coa, forming succinyl coa. -(remember this nadh (cid:3) h(cid:3) also. -you will see later what happens to it.) -5. now two molecules react with succinyl coa a molecule called gdp and one of phosphate (p). -the coa comes off, the gdp and p combine to form the high-energy compound gtp (similar to atp), and succinate remains. -(remember this gtp.) -c-14 appendix c 6. in the next reaction, two h with their electrons are re- moved from succinate and are transferred to a molecule of fad (a coenzyme like nad(cid:3)) to form fadh2. -the product that remains is fumarate. -(remember this fadh2.) -7. next a molecule of water is added to fumarate, forming malate. -8. a molecule of nad(cid:3) reacts with the malate; two h with their associated electrons are removed from the malate and form nadh (cid:3) h(cid:3). -the product that remains is the four-carbon compound oxaloacetate. -(remember this nadh (cid:3) h(cid:3).) -we are back where we started. -the oxaloacetate formed in this process can combine with another molecule of acetyl coa (step 1), and the cycle can begin again, as shown in figure c-4. -so far, we have seen two carbons brought in with acetyl coa and two carbons ending up in carbon dioxide. -but where are the energy and the atp we promised? -a review of the eight steps of the tca cycle shows that the compounds nadh + h+ (three molecules), fadh2, and gtp capture energy originally found in acetyl coa. -to see how this energy ends up in atp, we must follow the electrons further into the electron transport chain. -the electron transport chain the six reactions described here are those of the electron trans- port chain, which is shown in figure c-5. -since oxygen is re- quired for these reactions, and adp and p are combined to form atp in several of them (adp is phosphorylated), these reactions are also called oxidative phosphorylation. -an important concept to remember at this point is that an electron is not a xed amount of energy. -the electrons that bond the h to nad(cid:3) in nadh have a relatively large amount of en- ergy. -in the series of reactions that follow, they release this en- ergy in small amounts, until at the end they are attached (with h) to oxygen (o) to make water (h2o). -in some of the steps, the energy they release is captured into atp in coupled reactions. -1. in the rst step of the electron transport chain, nadh reacts with a molecule called a avoprotein, losing its electrons (and their h). -the products are nad(cid:3) and reduced avo- protein. -a little energy is released as heat in this reaction. -2. the flavoprotein passes on the electrons to a molecule called coenzyme q. again they release some energy as heat, but adp and p bond together and form atp, storing much of the energy. -this is a coupled reaction: adp (cid:3) p atp. -3. coenzyme q passes the electrons to cytochrome b. again the electrons release energy. -4. cytochrome b passes the electrons to cytochrome c in a coupled reaction in which atp is formed: adp (cid:3) p atp. -5. cytochrome c passes the electrons to cytochrome a. -6. cytochrome a passes them (with their h) to an atom of oxygen (o), forming water (h2o). -this is a coupled reac- tion in which atp is formed: adp (cid:3) p atp. -c x i d n e p p a as figure c-5 shows, each time nadh is oxidized (loses its electrons) by this means, the energy it releases is captured into three atp molecules. -when the electrons are passed on to water at the end, they are much lower in energy than they were orig- inally. -this completes the story of the electrons from nadh. -as for fadh2, its electrons enter the electron transport chain at coenzyme q. from coenzyme q to water, atp is gen- erated in only two steps. -therefore, fadh2 coming out of the tca cycle yields just two atp molecules. -one energy-receiving compound of the tca cycle (gtp) does not enter the electron transport chain but gives its en- ergy directly to adp in a simple phosphorylation reaction. -this reaction yields one atp. -it is now possible to draw up a balance sheet of glucose me- tabolism (see table c-3). -glycolysis has yielded 4 nadh (cid:3) h(cid:3) and 4 atp molecules and has spent 2 atp. -the 2 acetyl coa figure c-5 the electron transport chain acetyl coa oxaloacetate citrate malate tca cycle isocitrate fumarate alpha-ketoglutarate succinate succinyl coa 2h 2h 2h 2h fad adp + p nad+ 1 flavoprotein 2 coenzyme q 3 cytochrome b atp adp + p atp 4 cytochrome c 5 cytochrome a adp + p 6 atp 2h + o h2o going through the tca cycle have yielded 6 nadh (cid:3) h(cid:3), 2 fadh2, and 2 gtp molecules. -after the nadh (cid:3) h(cid:3) and fadh2 have gone through the electron transport chain, there are 28 atp. -added to these are the 4 atp from glycolysis and the 2 atp from gtp, making the total 34 atp generated from one molecule of glucose. -after the expense of 2 atp is sub- tracted, there is a net gain of 32 atp. -* a similar balance sheet from the complete breakdown of one 16-carbon fatty acid would show a net gain of 129 atp. -as mentioned earlier, 35 atp were generated from the seven fadh2 and seven nadh (cid:3) h(cid:3) produced during fatty acid ox- idation. -the eight acetyl coa produced will each generate 12 atp as they go through the tca cycle and the electron trans- port chain, for a total of 96 more atp. -after subtracting the 2 atp needed to activate the fatty acid initially, the net yield from one 16-carbon fatty acid: 35 (cid:3) 96 (cid:4) 2 (cid:5) 129 atp. -these calculations help explain why fat yields more energy (measured as kcalories) per gram than carbohydrate or protein. -the more hydrogen atoms a fuel contains, the more atp will be generated during oxidation. -the 16-carbon fatty acid mole- cule, with its 32 hydrogen atoms, generates 129 atp, whereas glucose, with its 12 hydrogen atoms, yields only 32 atp. -the tca cycle and the electron transport chain are the body s major means of capturing the energy from nutrients in atp molecules. -other means, such as anaerobic glycolysis, contribute energy quickly, but the aerobic processes are the most efficient. -biologists and chemists understand much more about these processes than has been presented here. -alcohol s interference with energy metabolism highlight 7 provides an overview of how alcohol interferes with energy metabolism. -with an understanding of the tca cycle, a few more details may be appreciated. -during alcohol metabolism, the enzyme alcohol dehydrogenase oxidizes al- cohol to acetaldehyde while it simultaneously reduces a mol- ecule of nad(cid:3) to nadh (cid:3) h(cid:3). -the related enzyme acetaldehyde dehydrogenase reduces another nad(cid:3) to nadh (cid:3) h(cid:3) while it oxidizes acetaldehyde to acetyl coa, the com- pound that enters the tca cycle to generate energy. -thus, whenever alcohol is being metabolized in the body, nad+ di- minishes, and nadh (cid:3) h(cid:3) accumulates. -chemists say that the body s redox state is altered, because nad(cid:3) can oxidize, and nadh (cid:3) h(cid:3) can reduce, many other body compounds. -during alcohol metabolism, nad(cid:3) becomes unavailable for the multitude of reactions for which it is required. -*the total may sometimes be 30 atp. -the nadh (cid:3) h(cid:3) generated in the cyto- plasm during glycolysis pass their electrons on to shuttle molecules, which move them into the mitochondria. -one shuttle, malate, contributes its elec- trons to the electron transport chain before the rst site of atp synthesis, yielding 5 atp. -another, glycerol phosphate, adds its electrons into the chain beyond that rst site, yielding 3 atp. -thus sometimes 5, and sometimes 3, atp result from the nadh (cid:3) h(cid:3) that arise from glycolysis. -the amount depends on the cell. -biochemical structures and pathways c-15 table c-3 balance sheet for glucose metabolism glycolysis: 1 glucose to 2 pyruvate 2 pyruvate to 2 acetyl coa 4 atp (cid:4) 2 atp 2 nadh (cid:3) h(cid:3) 2 nadh (cid:3) h(cid:3) tca cycle and electron transport chain: 2 isocitrate 2 alpha-ketoglutarate 2 nadh (cid:3) h(cid:3) 2 nadh (cid:3) h(cid:3) 2 succinyl coa 2 gtp 2 succinate 2 malate 2 fadh2 2 nadh (cid:3) h(cid:3) atp 2 3-5a 5 5 5 2 3 5 total atp collected from one molecule glucose: 30 32 aeach nadh (cid:3) h(cid:3) from glycolysis can yield 1.5 or 2.5 atp. -see the accompanying text. -c a p p e n d i x as the previous sections just explained, for glucose to be com- pletely metabolized, the tca cycle must be operating, and nad(cid:3) must be present. -if these conditions are not met (and when alco- hol is present, they may not be), the pathway will be blocked, and traf c will back up or an alternate route will be taken. -think about this as you follow the pathway shown in figure c-6. -in each step of alcohol metabolism in which nad+ is con- verted to nadh + h+, hydrogen ions accumulate, resulting in a dangerous shift of the acid-base balance toward acid (chapter 12 explains acid-base balance). -the accumulation of nadh (cid:3) h(cid:3) slows tca cycle activity, so pyruvate and acetyl coa build up. -this condition favors the conversion of pyruvate to lactate, which serves as a temporary storage place for hydrogens from nadh (cid:3) h(cid:3). -the conversion of pyruvate to lactate restores some nad(cid:3), but a lactate buildup has serious consequences of its own. -it adds to the body s acid burden and interferes with the excretion of uric acid, causing goutlike symptoms. -molecules of acetyl coa become building blocks for fatty acids or ketone bod- ies. -the making of ketone bodies consumes acetyl coa and gen- erates nad(cid:3); but some ketone bodies are acids, so they push the acid-base balance further toward acid. -thus alcohol cascades through the metabolic pathways, wreaking havoc along the way. -these consequences have physical effects, which highlight 7 describes. -the urea cycle chapter 7 sums up the process by which waste nitrogen is eliminated from the body by stating that ammonia molecules combine with carbon dioxide to produce urea. -this is true, but it is not the whole story. -urea is produced in a multistep process within the cells of the liver. -c-16 appendix c figure c-6 ethanol enters the metabolic path figure c-7 the urea cycle this is a simpli ed version of the glucose-to-energy pathway showing the entry of ethanol. -the coenzyme nad (which is the active form of the b vitamin niacin) is the only one shown here; however, many others are involved. -o c h2n nh2 urea glucose nad nadh nadh nad pyruvate lactic acid co2 ethanol nad nadh acetaldehyde nad nad nadh nadh acetyl coa nadh 1 nad 2 c x i d n e p p a 8 7 tca cycle ketone bodies, fatty acids, and fat nad nadh 3 nad nadh co2 4 nad nadh 6 5 co2 energy (atp), co2, h2o ammonia, freed from an amino acid or other compound during metabolism anywhere in the body, arrives at the liver by way of the bloodstream and is taken into a liver cell. -there, it is first combined with carbon dioxide and a phosphate group from atp to form carbamyl phosphate: 2 atp 2 adp + p o co2 + nh3 h2n oc o p o o carbon dioxide ammonia carbamyl phosphate nh2 ch2 ch2 ch2 h c nh2 cooh ornithine cooh nh2 ch2 c n c h nh cooh ch2 ch2 ch2 h c nh2 o c h2n carbamyl phosphate phosphate 1 h phosphate nh2 c o n h ch2 ch2 ch2 h c nh2 cooh citrulline 2 h2n atp cooh ch2 hc cooh cooh argininosuccinate amp + pp aspartic acid 4 nh2 c nh nh ch2 ch2 ch2 h c nh2 cooh arginine cooh 3 ch ch cooh fumarate figure c-7 shows the cycle of four reactions that follow. -1. carbamyl phosphate combines with the amino acid or- nithine, losing its phosphate group. -the compound formed is citrulline. -2. citrulline combines with the amino acid aspartic acid, to form argininosuccinate. -the reaction requires energy from atp. -(atp was shown earlier losing one phosphorus atom in a phosphate group, p, to become adp. -in this reaction, it loses two phosphorus atoms joined together, pp, and be- comes adenosine monophosphate, amp.) -3. argininosuccinate is split, forming another acid, fumarate, and the amino acid arginine. -4. arginine loses its terminal carbon with two attached amino groups and picks up an oxygen from water. -the end prod- uct is urea, which the kidneys excrete in the urine. -the compound that remains is ornithine, identical to the or- nithine with which this series of reactions began, and ready to react with another molecule of carbamyl phos- phate and turn the cycle again. -formation of ketone bodies normally, fatty acid oxidation proceeds all the way to carbon dioxide and water. -however, in ketosis (discussed in chapter 7), an intermediate is formed from the condensation of two molecules of acetyl coa: acetoacetyl coa. -figure c-8 shows the formation of ketone bodies from that intermediate. -figure c-8 the formation of ketone bodies o c h3c o ch2 c coa + h3c o c coa + acetoacetyl coa acetyl coa h2o water 1 ch3 o hooc ch2 c ch2 c coa + coa oh beta-hydroxy-beta-methylglutaryl coa coenzyme a 2 o o h3c c ch2 cooh + h3c c coa acetoacetate (a ketone body) acetyl coa nadh + h+ nad+ oh h3c c h 3a 3b o ch2 cooh h3c c ch3 + co2 beta-hydroxybutyrate (a ketone body) acetone (a ketone body) carbon dioxide biochemical structures and pathways c-17 1. acetoacetyl coa condenses with acetyl coa to form a six- carbon intermediate, beta-hydroxy-betamethylglutaryl coa. -2. this intermediate is cleaved to acetyl coa and acetoacetate. -3. acetoactate can be metabolized either to beta-hydroxybutyrate acid (step 3a) or to acetone (3b). -acetoacetate, beta-hydroxybutyrate, and acetone are the ketone bodies of ketosis. -two are real ketones (they have a c(cid:5)o group between two carbons); the other is an alcohol that has been produced during ketone formation hence the term ketone bodies, rather than ketones, to describe the three of them. -there are many other ketones in nature; these three are characteristic of ketosis in the body. -c a p p e n d i x appendix d contents amino acid scoring pdcaas biological value net protein utilizatin protein ef ciency ratio g lossary amino acid scoring: a measure of protein quality assessed by comparing a protein s amino acid pattern with that of a reference protein; sometimes called chemical scoring. -biological value (bv): a measure of protein quality assessed by measuring the amount of protein nitrogen that is retained from a given amount of protein nitrogen absorbed. -net protein utilization (npu): a measure of protein quality assessed by measuring the amount of protein nitrogen that is retained from a given amount of protein nitrogen eaten. -pdcaas (protein digestibility corrected amino acid score): a measure of protein quality assessed by comparing the amino acid score of a food protein with the amino acid requirements of preschool-age children and then correcting for the true digestibility of the protein; recommended by the fao/who and used to establish protein quality of foods for daily value percentages on food labels. -protein ef ciency ratio (per): a measure of protein quality assessed by determining how well a given protein supports weight gain in growing rats; used to establish the protein quality for infant formulas and baby foods. -d x i d n e p p a measures of protein quality in a world where food is scarce and many people s diets contain marginal or inadequate amounts of protein, it is important to know which foods contain the highest-quality pro- tein. -chapter 6 describes protein quality, and this appendix presents different measures researchers use to assess the quality of a food protein. -the accompanying glossary de- nes related terms. -amino acid scoring amino acid scoring evaluates a protein s quality by determining its amino acid com- position and comparing it with that of a reference protein. -the advantages of amino acid scoring are that it is simple and inexpensive, it easily identi es the limiting amino acid, and it can be used to score mixtures of different proportions of two or more proteins mathematically without having to make up a mixture and test it. -its chief weaknesses are that it fails to estimate the digestibility of a protein, which may strongly affect the protein s quality; it relies on a chemical procedure in which certain amino acids may be destroyed, making the pattern that is analyzed inaccurate; and it is blind to other fea- tures of the protein (such as the presence of substances that may inhibit the digestion or utilization of the protein) that would only be revealed by a test in living animals. -table d-1 (p. d-1) shows the reference pattern for the nine essential amino acids. -to interpret the table, read, for every 3210 units of essential amino acids, 145 must be his- tidine, 340 must be isoleucine, 540 must be leucine, and so on. -to compare a test pro- tein with the reference protein, the experimenter rst obtains a chemical analysis of the test protein s amino acids. -then, taking 3210 units of the amino acids, the experimenter compares the amount of each amino acid to the amount found in 3210 units of essential amino acids in egg protein. -for example, suppose the test protein contained (per 3210 units) 360 units of isoleucine; 500 units of leucine; 350 of lysine; and for each of the other amino acids, more units than egg protein contains. -the two amino acids that are low are leucine (500 as compared with 540 in egg) and lysine (350 versus 440 in egg). -the ratio, amino acid in the test protein divided by amino acid in egg, is 500/540 (or about 0.93) for leucine and 350/440 (or about 0.80) for lysine. -lysine is the limiting amino acid (the one that falls shortest compared with egg). -if the protein s limiting amino acid is 80 per- cent of the amount found in the reference protein, it receives a score of 80. pdcaas the protein digestibility corrected amino acid score, or pdcass, compares the amino acid composition of a protein with human amino acid requirements and corrects for digestibility. -first the protein s amino acid composition is determined, and then it is com- pared against the amino acid requirements of preschool-age children. -this comparison re- veals the most limiting amino acid the one that falls shortest compared with the reference. -if a food protein s limiting amino acid is 70 percent of the amount found in the reference protein, it receives a score of 70. the amino acid score is multiplied by the food s protein di- gestibility percentage to determine the pdcaas. -the box on p. d-2 provides an example of how to calculate the pdcaas, and table d-2 (p. d-1) lists the pdcaas values of selected foods. -biological value the biological value (bv) of a protein measures its efficiency in supporting the body s needs. -in a test of biological value, two nitrogen balance studies are done. -in the first, no protein is fed, and nitrogen (n) excretions in the urine and feces are measured. -it is assumed that under these conditions, n lost in the urine is the amount the body always necessarily loses by filtration into the urine each day, regard- less of what protein is fed (endogenous n). -the n lost in the fe- ces (called metabolic n) is the amount the body invariably loses into the intestine each day, whether or not food protein is fed. -(to help you remember the terms: endogenous n is uri- nary n on a zero-protein diet ; metabolic n is fecal n on a zero- protein diet. ) -in the second study, an amount of protein slightly below the requirement is fed. -intake and losses are measured; then the bv is derived using this formula: bv (cid:2) n retained (cid:3) 100 n absorbed measures of protein quality d-1 table d-1 of proteins a reference pattern for amino acid scoring essential amino acids reference protein whole egg (mg amino acid/g nitrogen) histidine isoleucine leucine lysine methionine (cid:4) cystinea phenylalanine (cid:4) tyrosineb threonine tryptophan valine total 145 340 540 440 355 580 294 106 410 3210 amethionine is essential and is also used to make cystine. -thus the methionine requirement is lower if cystine is supplied. -bphenylalanine is essential and is also used to make tyrosine if not enough of the latter is available. -thus the phenylalanine requirement is lower if tyrosine is also supplied. -the denominator of this equation expresses the amount of nitro- gen absorbed: food n minus fecal n (excluding the metabolic n the body would lose in the feces anyway, even without food). -the nu- merator expresses the amount of n retained from the n absorbed: absorbed n (as in the denominator) minus the n excreted in the urine (excluding the endogenous n the body would lose in the urine anyway, even without food). -the more nitrogen retained, the higher the protein quality. -(recall that when an essential amino acid is missing, protein synthesis stops, and the remaining amino acids are deaminated and the nitro- gen excreted.) -egg protein has a bv of 100, indicating that 100 percent of the nitrogen absorbed is retained. -supplied in adequate quantity, a protein with a bv of 70 or greater can sup- port human growth as long as energy intake is adequate. -table d-3 presents the bv for selected foods. -this method has the advantages of being based on experiments with human beings (it can be done with animals, too, of course) and of measuring actual nitrogen reten- tion. -but it is also cumbersome, expensive, and often impractical, and it is based on several assumptions that may not be valid. -for example, the physiology, normal envi- ronment, or typical food intake of the subjects used for testing may not be similar to those for whom the test protein may ultimately be used. -for another example, the re- tention of protein in the body does not necessarily mean that it is being well utilized. -considerable exchange of protein among tissues (protein turnover) occurs, but is hid- den from view when only n intake and output are measured. -the test of biological value wouldn t detect if one tissue were shorted. -net protein utilization like bv, net protein utilization (npu) measures how ef ciently a protein is used by the body and involves two balance studies. -the difference is that npu measures reten- tion of food nitrogen rather than food nitrogen absorbed (as in bv). -the formula for npu is: npu (cid:2) n retained (cid:3) 100 n intake the numerator is the same as for bv, but the denominator represents food n intake only not n absorbed. -this method offers advantages similar to those of bv determinations and is used more frequently, with animals as the test subjects. -a drawback is that if a low npu is obtained, the test results offer no help in distinguishing between two possible causes: a poor amino acid composition of the test protein or poor digestibility. -there is also a limit to the extent to which animal test results can be assumed to be applicable to hu- man beings. -d a p p e n d i x table d-2 selected foods pdcaas values of casein (milk protein) egg white soybean (isolate) beef pea our kidney beans (canned) chickpeas (canned) pinto beans (canned) rolled oats lentils (canned) peanut meal whole wheat 1.00 1.00 .99 .92 .69 .68 .66 .66 .57 .52 .52 .40 note: 1.0 is the maximum pdcaas a food protein can receive. -table d-3 of selected foods biological values (bv) egg milk beef fish corn 100 93 75 75 72 note: 100 is the maximum bv a food protein can receive. -d-2 appendix d how to measure protein quality using pdcaas to calculate the pdcaas (protein digestibil- ity corrected amino acid score), researchers rst determine the amino acid pro le of the test protein (in this example, pinto beans). -the second column of the table below presents the essential amino acid pro le for pinto beans. -the third column presents the amino acid reference pattern. -to determine how well the food protein meets human needs, researchers calculate the ratio by dividing the second column by the third column (for example, 30 (cid:5) 18 (cid:2) 1.67). -the amino acid with the lowest ratio is the most limiting amino acid in this case, methionine. -its ratio is the amino acid score for the protein in this case, 0.84. the amino acid score alone, however, does not account for digestibility. -protein digestibility, as determined by rat studies, yields a value of 79 percent for pinto beans. -together, the amino acid score and the digestibility value determine the pdcaas: pdcaas = protein digestibility (cid:3) amino acid score pdcaas for pinto beans (cid:2) 0.79 (cid:3) 0.84 (cid:2) 0.66 thus the pdcaas for pinto beans is 0.66. table d-2 lists the pdcaas values of se- lected foods. -the pdcaas is used to determine the % daily value on food labels. -to calculate the % daily value for protein for canned pinto beans, multiply the number of grams of protein in a standard serving (in the case of pinto beans, 7 grams per 1 2 cup) by the pdcaas: 7 g (cid:3) 0.66 (cid:2) 4.62 this value is then divided by the recom- mended standard for protein (for children over age four and adults, 50 grams): 4.62 (cid:5) 50 (cid:2) 0.09 (or 9%) the food label for this can of pinto beans would declare that one serving provides 7 grams protein, and if the label included a % daily value for protein (which is op- tional), the value would be 9 percent. -amino acid pro le of pinto beans (mg/g protein) amino acid reference pattern (mg/g protein) amino acid score 30.0 42.5 80.4 69.0 21.1 90.5 43.7 8.8 50.1 18 25 55 51 25 47 27 7 32 1.67 1.70 1.46 1.35 0.84 1.93 1.62 1.26 1.57 essential amino acids histidine isoleucine leucine lysine methionine ((cid:4) cystine) phenylalanine ((cid:4) tyrosine) threonine tryptophan valine d x i d n e p p a protein ef ciency table d-4 ratio (per) values of selected proteins casein (milk) soy glutein (wheat) 2.8 2.4 0.4 protein ef ciency ratio the protein ef ciency ratio (per) measures the weight gain of a growing animal and compares it to the animal s protein intake. -until recently, the per was generally accepted in the united states and canada as the of cial method for assessing protein quality, and it is still used to evaluate proteins for infants. -young rats are fed a measured amount of protein and weighed periodically as they grow. -the per is expressed as: per (cid:2) weight gain (g) protein intake (g) this method has the virtues of economy and simplicity, but it also has many draw- backs. -the experiments are time-consuming; the amino acid needs of rats are not the same as those of human beings; and the amino acid needs for growth are not the same as for the maintenance of adult animals (growing animals need more lysine, for example). -table d-4 presents per values for selected foods. -nutrition assessment e-1 nutrition assessment nutrition assessment evaluates a person s health from a nutrition perspective. -many factors in uence or re ect nutrition status. -consequently, the assessor, usu- ally a registered dietitian assisted by other quali ed health care professionals, gathers information from many sources, including: contents historical information anthropometric measurements physical examinations biochemical analyses cautions about nutrition assessment historical information. -anthropometric measurements. -physical examinations. -biochemical analyses (laboratory tests). -each of these methods involves collecting data in a variety of ways and interpret- ing each nding in relation to the others to create a total picture. -the accurate gathering of this information and its careful interpretation are the basis for a meaningful evaluation. -the more information gathered about a person, the more accurate the assessment will be. -gathering information is a time-consuming process, however, and time is often a rare commodity in the health care setting. -nutrition care is only one part of total care. -it may not be practical or essential to collect detailed information on each person. -a strategic compromise is to screen clients by collecting preliminary data. -data such as height-weight and hematocrit are easy to obtain and can alert health care workers to potential problems. -nutrition screening identifies clients who will require additional nutrition assessment. -this appendix provides a sample of the procedures, standards, and charts commonly used in nutrition assessment. -historical information clues about present nutrition status become evident with a careful review of a per- son s historical data (see table e-1). -even when the data are subjective, they reveal important facts about a person. -a thorough history identi es risk factors associ- ated with poor nutrition status (see table e-2) and provides a sense of the whole person. -as you can see, many aspects of a person s life in uence nutrition status and provide clues to possible problems. -an adept history taker uses the interview both to gather facts and to establish a rapport with the client. -this section brie y reviews the major areas of nutrition concern in a person s history: health, socioeconomic factors, drugs, and diet. -table e-1 historical data used in nutrition assessments type of history what it identi es health history current and previous health problems and family health history that affect nutrient needs, nutrition status, or the need for intervention to prevent or alleviate health problems socioeconomic history personal, cultural, nancial, and environmental in uences on food intake, nutrient needs, and diet therapy options drug history medications (prescription and over-the-counter), illicit drugs, dietary supplements, and alternative therapies that affect nutrition status diet history nutrient intake excesses or de ciencies and reasons for imbalances e a p p e n d i x nutrition screening: the use of preliminary nutrition assessment techniques to identify people who are malnourished or are at risk for malnutrition. -e-2 appendix e table e-2 risk factors for poor nutrition status health history acquired immune de ciency syndrome (aids) alcoholism anorexia (lack of appetite) anorexia nervosa bulimia nervosa burns cancer chewing or swallowing dif culties (including poorly tted dentures, dental caries, missing teeth, and mouth ulcers) chronic obstructive pulmonary disease circulatory problems constipation crohn s disease cystic brosis decubitus ulcers (pressure sores) dementia depleted blood proteins depression diabetes mellitus socioeconomic history diarrhea, prolonged or severe drug addiction dysphagia failure to thrive feeding disabilities fever gi tract disorders or surgery heart disease hiv infection hormonal imbalance hyperlipidemia hypertension infections kidney disease liver disease lung disease malabsorption mental illness mental retardation multiple pregnancies nausea neurologic disorders organ failure overweight pancreatic insuf ciency paralysis physical disability pneumonia pregnancy radiation therapy recent major illness recent major surgery recent weight loss or gain tobacco use trauma ulcerative colitis ulcers underweight vomiting, prolonged or severe ethnic identity income kitchen facilities number of people in household occupation religious af liation access to groceries activities age education drug history amphetamines analgesics antacids antibiotics anticonvulsant agents antidepressant agents antidiabetic agents diet history e x i d n e p p a antidiarrheals antifungal agents antihyperlipemics antihypertensives antineoplastics antiulcer agents antiviral agents catabolic steroids diuretics hormonal agents immunosuppressive agents laxatives oral contraceptives vitamin and other dietary supplements unbalanced diet (omitting any food group) recent weight gains or losses de cient or excessive food intakes frequently eating out intravenous uids (other than total parenteral nutrition) for 7 or more days monotonous diet (lacking variety) no intake for 7 or more days poor appetite restricted or fad diets health history the assessor can obtain a health history from records completed by the at- tending physician, nurse, or other health care professional. -in addition, conver- sations with the client can uncover valuable information previously overlooked because no one thought to ask or because the client was not thinking clearly when asked. -an accurate, complete health history can reveal conditions that increase a client s risk for malnutrition (review table e-2). -diseases and their therapies can have either immediate or long-term effects on nutrition status by interfering with ingestion, digestion, absorption, metabolism, or excretion of nutrients. -health history: an account of a client s current and past health status and disease risks. -socioeconomic history a socioeconomic history reveals factors that profoundly affect nutrition status. -the ethnic background and educational level of both the client and the other mem- bers of the household in uence food availability and food choices. -an understand- ing of the community environment is also important in assessing nutrition status. -for example, the interviewer should be familiar with the food habits of the major ethnic groups within the locale, regional food preferences, and nutrition resources and programs available in the community. -local health departments and social agencies often can provide such information. -level of income also in uences the diet. -in general, the quality of the diet declines as income falls. -at some point, the ability to purchase the foods required to meet nutrient needs is lost; an inadequate income puts an adequate diet out of reach. -agencies use poverty indexes to identify people at risk for poor nutrition and to qualify people for government food assistance programs. -low income affects not only the power to purchase foods but also the ability to shop for, store, and cook them. -a skilled assessor will note whether a person has transportation to a grocery store that sells a suf cient variety of low-cost foods, and whether the person has access to a refrigerator and stove. -drug history the many interactions of foods and drugs require that health care professionals take a drug history and pay special attention to any client who takes drugs routinely. -if a person is taking any drug, the assessor records the name of the drug; the dose, fre- quency, and duration of intake; the reason for taking the drug; and signs of any ad- verse effects. -the interactions of drugs and nutrients may take many forms: drugs can alter food intake and the absorption, metabolism, and excretion of nutrients. -foods and nutrients can alter the absorption, metabolism, and excretion of drugs. -highlight 17 discusses nutrient-drug interactions in more detail, and table h17-1 (p. 616) summarizes the mechanisms by which these interactions occur and pro- vides speci c examples. -diet history a diet history provides a record of a person s eating habits and food intake and can help identify possible nutrient imbalances. -food choices are an important part of lifestyle and often re ect a person s philosophy. -the assessor who asks nonjudg- mental questions about eating habits and food intake encourages trust and en- hances the likelihood of obtaining accurate information. -assessors evaluate food intake using various tools such as the 24-hour recall, the usual intake record, the food record, and the food frequency questionnaire. -food models or photos and measuring devices can help clients identify the types of foods and quantities consumed. -the assessor also needs to know how the foods are pre- pared and when they are eaten. -in addition to asking about foods, assessors will ask about beverage consumption, including beverages containing alcohol or caffeine. -besides identifying possible nutrient imbalances, diet histories provide valu- able clues about how a person will accept diet changes should they be necessary. -information about what and how a person eats provides the background for real- istic and attainable nutrition goals. -24-hour recall the 24-hour recall provides data for one day only and is com- monly used in nutrition surveys to obtain estimates of the typical food intakes for a population. -the assessor asks the client to recount everything eaten or drunk in the past 24 hours or for the previous day. -nutrition assessment e-3 e a p p e n d i x socioeconomic history: a record of a person s social and economic background, including such factors as education, income, and ethnic identity. -drug history: a record of all the drugs, over- the-counter and prescribed, that a person takes routinely. -diet history: a record of eating behaviors and the foods a person eats. -24-hour recall: a record of foods eaten by a person for one 24-hour period. -e-4 appendix e e x i d n e p p a food record: an extensive, accurate log of all foods eaten over a period of several days or weeks. -a food record that includes associated information such as when, where, and with whom each food is eaten is sometimes called a food diary. -food frequency questionnaire: a checklist of foods on which a person can record the frequency with which he or she eats each food. -an advantage of the 24-hour recall is that it is easy to obtain. -it is also more likely to provide accurate data, at least about the past 24 hours, than estimates of average intakes over long periods. -it does not, however, provide enough informa- tion to allow accurate generalizations about an individual s usual food intake. -the previous day s intake may not be typical, for example, or the person may be unable to report portion sizes accurately or may conceal or forget information about foods eaten. -this limitation is partially overcome when 24-hour recalls are collected on several nonconsecutive days. -usual intake to obtain data about a person s usual intake, an inquiry might be- gin with what is the rst thing you usually eat or drink during the day? -similar questions follow until a typical daily intake pattern emerges. -this method can be useful, especially in verifying food intake when the past 24 hours have been atyp- ical. -it also helps the assessor verify food habits. -for example, one person may al- ways eat an afternoon snack; another may never eat breakfast. -a person whose intake varies widely from day to day, however, may nd it dif cult to answer such general questions, and in that case, another food intake tool should be used to es- timate nutrient intake. -food record another tool for history taking is the food record, in which the person records food eaten, including the quantity and method of preparation. -chapter 9 (p. 304) provides an example. -a food record can help both the assessor and the client to determine factors associated with eating that may affect dietary balance and adequacy. -food records work especially well with cooperative people but require consider- able time and effort on their part. -a prime advantage is that the record keeper as- sumes an active role and may for the rst time become aware of personal food habits and assume responsibility for them. -it also provides the assessor with an ac- curate picture of the person s lifestyle and factors that affect food intake. -for these reasons, a food record can be particularly useful in outpatient counseling for such nutrition problems as overweight, underweight, or food allergy. -the major disad- vantages stem from poor compliance in recording the data and conscious or un- conscious changes in eating habits that may occur while the person is keeping the record. -food frequency questionnaire an assessor uses a food frequency ques- tionnaire to compare a client s food intake with the daily food guide. -clients may be asked how many servings of each of the following they eat in a typical day: breads, cereals, or grain products; vegetables; fruits; meat, poultry, sh, and alternatives; milk, cheese, and yogurt; and fats, oils, and sweets. -this informa- tion helps pinpoint food groups, and therefore nutrients, that may be excessive or de cient in the diet. -that a person ate no vegetables yesterday may not seem particularly signi cant, but never eating vegetables is a warning of possible nu- trient de ciencies. -when used with the usual intake or 24-hour recall approach, the food frequency questionnaire enables the assessor to double-check the accu- racy of the information obtained. -analysis of food intake data after collecting food intake data, the assessor es- timates nutrient intakes, either informally by using food guides or formally by using food composition tables. -the assessor compares these intakes with standards, usually nutrient recommendations or dietary guidelines, to determine how closely the per- son s diet meets the standards. -are the types and amounts of proteins, carbohydrates (including ber), and fats (including cholesterol) appropriate? -are all food groups in- cluded in appropriate amounts? -is caffeine or alcohol consumption excessive? -are in- takes of any vitamins or minerals (including sodium and iron) excessive or de cient? -an informal evaluation is possible only if the assessor has enough prior experience with formal calculations to see nutrient amounts in reported food intakes without calculations. -even then, such an informal analysis is best followed by a spot check for key nutrients by actual calculation. -formal calculations can be performed either manually (by looking up each food in a table of food composition, recording its nutrients, and adding them up) or by using a computer diet analysis program. -the assessor then compares the in- takes with standards such as the rda. -limitations of food intake analysis diet histories can be superbly informa- tive, but the skillful assessor also keeps their limitations in mind. -for example, a computer diet analysis tends to imply greater accuracy than is possible to obtain from data as uncertain as the starting information. -nutrient contents of foods listed in tables of food composition or stored in computer databases are averages and, for some nutrients, incomplete. -in addition, the available data on nutrient contents of foods do not re ect the amounts of nutrients a person actually absorbs. -iron is a case in point: its availability from a given meal may vary depending on the person s iron status; the relative amounts of heme iron, nonheme iron, vita- min c, meat, sh, and poultry eaten at the meal; and the presence of inhibitors of iron absorption such as tea, coffee, and nuts. -(chapter 13 describes the many fac- tors that in uence iron absorption from a meal.) -furthermore, reported portion sizes may not be correct. -the person who reports eating a serving of greens may not distinguish between 1 4 cup and 2 whole cups; only trained individuals can accurately report serving sizes. -children tend to re- member the serving sizes of foods they like as being larger than serving sizes of foods they dislike. -an estimate of nutrient intakes from a diet history, combined with other sources of information, allows the assessor to con rm or eliminate the possibility of suspected food intake problems. -the assessor must constantly remember that nutrient intakes in adequate amounts do not guarantee adequate nutrient status for an individual. -likewise, insuf cient intakes do not always indicate de cien- cies, but instead alert the assessor to possible problems. -each person digests, ab- sorbs, metabolizes, and excretes nutrients in a unique way; individual needs vary. -intakes of nutrients identi ed by diet histories are only pieces of a puzzle that must be put together with other indicators of nutrition status in order to extract meaning. -anthropometric measurements anthropometrics are physical measurements that re ect body composition and development (see table e-3). -they serve three main purposes: rst, to evaluate the progress of growth in pregnant women, infants, children, and adolescents; second, to detect undernutrition and overnutrition in all age groups; and third, to mea- sure changes in body composition over time. -health care professionals compare anthropometric measurements taken on an individual with population standards speci c for gender and age or with previous measures of the individual. -measurements taken periodically and compared with previous measurements reveal changes in an individual s status. -table e-3 anthropometric measurements used in nutrition assessments type of measurement what it re ects abdominal girth measurement abdominal uid retention and abdominal organ size height-weight head circumference overnutrition and undernutrition; growth in children brain growth and development in infants and children under age two skinfold subcutaneous and total body fat waist circumference body fat distribution nutrition assessment e-5 e a p p e n d i x anthropometrics: measurements of the physical characteristics of the body, such as height and weight. -anthropos (cid:2) human metric (cid:2) measuring e-6 appendix e figure e-1 of an infant length measurement an infant is measured lying down on a measuring board with a xed head- board and a movable footboard. -note that two people are needed to measure the infant s length. -figure e-2 height measurement of an older child or adult height is measured most accurately when the person stands against a at wall to which a measuring tape has been af xed. -e x i d n e p p a mastering the techniques for taking anthropometric measurements requires proper instruction and practice to ensure reliability. -once the correct techniques are learned, taking measurements is easy and requires minimal equipment. -height and weight are well-recognized anthropometrics; other anthropomet- rics include skinfold measurements and various measures of lean tissue. -other mea-sures are useful in speci c situations. -for example, a head circumference measurement may help to assess brain development in an infant, and an ab- dominal girth measurement supplies information about abdominal uid reten- tion in individuals with liver disease. -measures of growth and development height and weight are among the most common and useful anthropometric mea- surements. -length measurements for infants and children up to age three and height measurements for children over three are particularly valuable in assessing growth and therefore nutrition status. -for adults, height measurements alone are not critical, but help to estimate healthy weight and to interpret other assessment data. -once adult height has been reached, changes in body weight provide useful information in assessing overnutrition and undernutrition. -height for infants and children younger than three, health care professionals may use special equipment to measure length. -the assessor lays the barefoot in- fant on a measuring board that has a xed headboard and movable footboard at- tached at right angles to the surface (see figure e-1). -often two people are needed to obtain an accurate measurement: one to hold the infant s head against the headboard, and the other to keep the legs straight and do the measuring. -this method provides the most accurate measure possible, but many health care pro- fessionals use a less exacting method. -they may simply hold the infant straight with its head against the headboard or other vertical support, mark the blanket with a chalk or pen at the infant s heel, and then measure the distance from the headboard to the mark. -even more informally and less accurately, they may lay the infant on a at surface and extend a nonstretchable measuring tape along the side of the infant from the top of the head to the heel of the foot. -the procedure for measuring a child who can stand erect and cooperate is the same as for an adult. -the best way to measure standing height is with the person s back against a at wall to which a nonstretchable measuring tape or stick has been xed (see figure e-2). -the person stands erect, without shoes, with heels to- gether. -the person s line of sight should be horizontal, with the heels, buttocks, shoulders, and head touching the wall. -the assessor places a ruler, book, or other in exible object on top of the head at a right angle to the wall; carefully checks the height measurement; and records it immediately in either inches or centime- ters so that the correct measurement will not be forgotten. -the measuring rod of a scale is commonly used, but is less accurate because it bends easily. -the assessor follows the same general procedure, asking the person to face away from the scale and to take extra care to stand erect. -unfortunately, many health care professionals merely ask clients how tall they are rather than measuring their height. -self-reported height is often inaccurate and should be used only as a last resort when measurement is impractical (in the case of an uncooperative client, an emergency admission, or the like). -weight valid weight measurements require scales that have been carefully main- tained, calibrated, and checked for accuracy at regular intervals. -beam balance and electronic scales are the most accurate types of scales. -to measure infants weight, as- sessors use special scales that allow infants to lie or sit (see figure e-3). -weighing in- fants naked, without diapers, is standard procedure. -children who can stand are weighed in the same way as adults (see figure e-4). -to make repeated measures use- ful, standardized conditions are necessary. -each weighing should take place at the same time of day (preferably before breakfast), in the same amount of clothing (with- nutrition assessment e-7 figure e-3 weight measurement of an infant infants sit or lie down on scales that are designed to hold them while they are being weighed. -chapter 16 presents bmi charts for chil- dren and adolescents. -reminder: the body mass index (bmi) is an index of a person s weight in relation to height, determined by dividing the weight in kilograms by the square of the height in meters: bmi (cid:2) weight (kg) height (m)2 figure e-4 weight measurement of an older child or adult whenever possible, children and adults are measured on beam balance or elec- tronic scales to ensure accuracy. -e a p p e n d i x out shoes), after the person has voided, and on the same scale. -special scales and hos- pital beds with built-in scales are available for weighing people who are bedridden. -bathroom scales are inaccurate and inappropriate in a professional setting. -as with all measurements, the assessor records the observed weight immediately in either pounds or kilograms. -head circumference assessors may also measure head circumference to con rm that infant growth is proceeding normally or to help detect protein-energy malnutri- tion (pem) and evaluate the extent of its impact on brain size. -to measure head cir- cumference, the assessor places a nonstretchable tape so that it encircles the largest part of the infant s or child s head: just above the eyebrow ridges, just above the point where the ears attach, and around the occipital prominence at the back of the head. -to ensure accurate recording, the assessor immediately notes the measure in either inches or centimeters. -analysis of measures in infants and children growth retardation is a sign of poor nutrition status. -obesity is also a sign that dietary intervention may be needed. -health professionals generally evaluate physical development by monitoring the growth rate of a child and comparing this rate with standard charts. -standard charts compare weight to age, height to age, and weight to height; ideally, height and weight are in roughly the same percentile. -although individual growth pat- terns may vary, a child s growth curve will generally stay at about the same per- centile throughout childhood. -in children whose growth has been retarded, nutrition rehabilitation will ideally induce height and weight to increase to higher percentiles. -in overweight children, the goal is for weight to remain stable as height increases, until weight becomes appropriate for height. -to evaluate growth in infants, an assessor uses charts such as those in figures e- 5 (a and b) through e-10 (a and b). -the assessor follows these steps to plot a weight measurement on a percentile graph: select the appropriate chart based on age and gender. -locate the child s age along the horizontal axis on the bottom of the chart. -locate the child s weight in pounds or kilograms along the vertical axis. -mark the chart where the age and weight lines intersect, and read off the percentile. -to assess length, height, or head circumference, the assessor follows the same pro- cedure, using the appropriate chart. -(when length is measured, use the chart for birth to 36 months; when height is measured, use the chart for 2 to 20 years.) -head circumference percentile should be similar to the child s height and weight per- centiles. -with height, weight, and head circumference measures plotted on growth percentile charts, a skilled clinician can begin to interpret the data. -percentile charts divide the measures of a population into 100 equal divisions. -thus half of the population falls above the 50th percentile, and half falls below. -the use of percentile measures allows for comparisons among people of the same age and gender. -for example, a six-month-old female infant whose weight is at the 75 percentile weighs more than 75 percent of the female infants her age. -head circumference is generally measured in children under two years of age. -since the brain grows rapidly before birth and during early infancy, extreme and chronic malnutrition during these times can impair brain development, curtailing the number of brain cells and the size of head circumference. -nonnutritional factors, such as certain disorders and genetic variation, can also in uence head circumference. -analysis of measures in adults for adults, health care professionals typically compare weights with weight-for-height standards. -one such standard is the body mass index (bmi), described in chapter 8 (pp. -259 260), which is useful for esti- mating the risk to health associated with overnutrition. -the back cover shows bmi for various heights and weights. -figure e-5a weight-for-age percentiles: boys, birth to 36 months figure e-5b weight-for-age percentiles: girls, birth to 36 months appendix e e - 8 a p p e n d i x e figure e-6a length-for-age percentiles: boys, birth to 36 months figure e-6b length-for-age percentiles: girls, birth to 36 months n u t r i i t o n a s s e s s m e n t e - 9 e appendix figure e-7a weight-for-length percentiles: boys, birth to 36 months figure e-7b weight-for-length percentiles: girls, birth to 36 months appendix e e - 1 0 a p p e n d i x e figure e-8a weight-for-age percentiles: boys, 2 to 20 years figure e-8b weight-for-age percentiles: girls, 2 to 20 years n u t r i i t o n a s s e s s m e n t e - 1 1 e appendix figure e-9a stature-for-age percentiles: boys, 2 to 20 years figure e-9b stature-for-age percentiles: girls, 2 to 20 years appendix e e - 1 2 a p p e n d i x e figure e-10a weight-for-stature percentiles: boys, 2 to 20 years figure e-10b weight-for-stature percentiles: girls, 2 to 20 years n u t r i i t o n a s s e s s m e n t e - 1 3 e appendix e-14 appendix e common sites for skinfold measures: triceps biceps subscapular (below shoulder blade) suprailiac (above hip bone) abdomen upper thigh measures of body fat and lean tissue signi cant weight changes in both children and adults can re ect overnutrition and undernutrition with respect to energy and protein. -to estimate the degree to which fat stores or lean tissues are affected by overnutrition or malnutrition, several an- thropometric measurements are useful (review table e-3 on p. e-5). -skinfold measures skinfold measures provide a good estimate of total body fat and a fair assessment of the fat s location. -approximately half the fat in the body lies directly beneath the skin, and the thickness of this subcutaneous fat re ects to- tal body fat. -in some parts of the body, such as the back and the back of the arm over the triceps muscle, this fat is loosely attached; a person can pull it up be- tween the thumb and fore nger to obtain a measure of skinfold thickness. -to measure skinfold, a skilled assessor follows a standard procedure using reliable calipers (illustrated in figure e-11) and then compares the measurement with standards. -triceps skinfold measures greater than 15 millimeters in men or 25 mil- limeters in women suggest excessive body fat. -skinfold measurements correlate directly with the risk of heart disease. -they as- sess central obesity and its associated risks better than do weight measures alone. -if a person gains body fat, the skinfold increases proportionately; if the person loses fat, it decreases. -measurements taken from central-body sites (around the ab- domen) better re ect changes in fatness than those taken from upper sites (arm and back). -a major limitation of the skinfold test is that fat may be thicker under the skin in one area than in another. -a pinch at the side of the waistline may not yield the same measurement as a pinch on the back of the arm. -this limitation can be overcome by taking skinfold measurements at several (often three) differ- figure e-11 how to measure the triceps skinfold e x i d n e p p a clavicle acromion process midpoint a. find the midpoint of the arm: 1. ask the subject to bend his or her arm at the elbow and lay the hand across the stomach. -(if he or she is right-handed, measure the left arm, and vice versa.) -2. feel the shoulder to locate the acro- mion process. -it helps to slide your n- gers along the clavicle to nd the acro- mion process. -the olecranon process is the tip of the elbow. -3. place a measuring tape from the acromion process to the tip of the elbow. -divide this measurement by 2, and mark the midpoint of the arm with a pen. -olecranon process b. measure the skinfold: 1. ask the subject to let his or her arm hang loosely to the side. -2. grasp a fold of skin and subcuta- neous fat between the thumb and fore- nger slightly above the midpoint mark. -gently pull the skin away from the underlying muscle. -(this step takes a lot of practice. -if you want to be sure you don t have muscle as well as fat, ask the subject to contract and relax the muscle. -you should be able to feel if you are pinching muscle.) -3. place the calipers over the skinfold at the midpoint mark, and read the measure- ment to the nearest 1.0 millimeter in two to three seconds. -(if using plastic calipers, align pressure lines, and read the measurement to the nearest 1.0 millimeter in two to three sec- onds.) -4. repeat steps 2 and 3 twice more. -add the three readings, and then divide by 3 to nd the average. -figure e-12 how to measure waist circumference place the measuring tape around the waist just above the bony crest of the hip. -the tape runs parallel to the oor and is snug (but does not compress the skin). -the measurement is taken at the end of normal expiration. -nutrition assessment e-15 source: national institutes of health obesity education initiative, clinical guidelines on the identi cation, evaluation, and treatment of overweight and obesity in adults (washington, d.c.: u.s. department of health and human services, 1998), p. 59. ent places on the body (including upper-, central-, and lower-body sites) and com- paring each measurement with standards for that site. -multiple measures are not always practical in clinical settings, however, and most often, the triceps skinfold measurement alone is used because it is easily accessible. -skinfold measures are not useful in assessing changes in body fat over time.1 waist circumference chapter 8 described how fat distribution correlates with health risks and mentioned that the waist circumference is a valuable indicator of fat distribution. -to measure waist circumference, the assessor places a nonstretch- able tape around the person s body, crossing just above the upper hip bones and making sure that the tape remains on a level horizontal plane on all sides (see fig- ure e-12). -the tape is tightened slightly, but without compressing the skin. -waist-to hip ratio alternatively, some clinicians measure both the waist and the hips. -the waist-to-hip ratio also assesses abdominal obesity, but provides no more information than using the waist circumference alone. -in general, women with a waist-to-hip ratio of 0.80 or greater and men with a waist-to-hip ratio of 0.90 or greater have a high risk of health problems. -hydrodensitometry to estimate body density using hydrodensitometry, the per- son is weighed twice rst on land and then again when submerged under water. -underwater weighing usually generates a good estimate of body fat and is useful in research, although the technique has drawbacks: it requires bulky, expensive, and nonportable equipment. -furthermore, submerging some people (especially those who are very young, very old, ill, or fearful) under water is not always practical. -e a p p e n d i x to calculate the waist-to-hip ratio, divide the waistline measurement by the hip measurement. -for example, a woman with a 28-inch waist and 38-inch hips would have a ratio of 28 (cid:3) 38 (cid:2) 0.74. e-16 appendix e bioelectric impedance to measure body fat using the bioelectric impedance technique, a very-low-intensity electrical current is brie y sent through the body by way of electrodes placed on the wrist and ankle. -as is true of other anthropo- metric techniques, bioelectrical impedance requires standardized procedures and calibrated instruments to provide reliable results. -recent food intake and hydra- tion status, for example, in uence results. -bioelectrical impedance is most accu- rate for people within a normal fat range; it tends to overestimate fat in lean people and underestimate fat in obese people.2 clinicians use many other methods to estimate body fat and its distribution. -each has its advantages and disadvantages as table e-4 summarizes. -physical examinations an assessor can use a physical examination to search for signs of nutrient de ciency or toxicity. -like the other assessment methods, such an examination requires knowl- edge and skill. -many physical signs are nonspeci c; they can re ect any of several nutrient de ciencies as well as conditions not related to nutrition (see table e-5). -for example, cracked lips may be caused by sunburn, windburn, dehydration, or any of several b vitamin de ciencies, to name just a few possible causes. -for this reason, physical ndings are most valuable in revealing problems for other assessment techniques to con rm or for con rming other assessment measures. -with this limitation understood, physical symptoms can be most informative and communicate much information about nutrition health. -many tissues and or- gans can re ect signs of malnutrition. -the signs appear most rapidly in parts of the body where cell replacement occurs at a high rate, such as in the hair, skin, and di- gestive tract (including the mouth and tongue). -the summary tables in chapters 10, 11, 12, and 13 list additional physical signs of vitamin and mineral malnutrition. -biochemical analyses all of the approaches to nutrition assessment discussed so far are external ap- proaches. -biochemical analyses or laboratory tests help to determine what is hap- pening to the body internally. -common tests are based on analysis of blood and e x i d n e p p a table e-4 methods of estimating body fat and its distribution method height and weight skinfolds circumferences ultrasound hydrodensitometry heavy water tritiated deuterium oxide, or heavy oxygen potassium isotope (40k) total body electrical conductivity (tobec) bioelectric impedance (bia) dual energy x-ray absorptiometry (dexa) computed tomography (ct) magnetic resonance imaging (mri) cost low low low moderate low moderate high very high high moderate high very high very high ease of use easy easy easy moderate moderate moderate moderate dif cult moderate easy easy dif cult dif cult accuracy high low moderate moderate high high high high high high high high high measures fat distribution no yes yes yes no no no no no no no yes yes source: adapted with permisssion from g. a. bray, a handout presented at the north american association for the study of obesity and emory university school of medicine conference on obesity. -update: pathophysiology, clinical consequences, and therapeutic options, atlanta, georgia, august 31-september 2, 1992. table e-5 physical findings used in nutrition assessments body system healthy findings malnutrition findings what the findings re ect nutrition assessment e-17 hair eyes teeth and gums glands tongue skin nails internal systems shiny, rm in the scalp dull, brittle, dry, loose; falls out pem bright, clear pink membranes; adjust easily to light no pain or caries, gums rm, teeth bright pale membranes; spots; redness; adjust slowly to darkness vitamin a, b vitamin, zinc, and iron status missing, discolored, decayed teeth; gums bleed easily and are swollen and spongy mineral and vitamin c status no lumps swollen at front of neck pem and iodine status red, bumpy, rough sore, smooth, purplish, swollen b vitamin status smooth, rm, good color off-color, scaly, aky, cracked, dry, rough, spotty; sandpaper feel or sores; lack of fat under skin pem, essential fatty acid, vitamin a, b vitamin, and vitamin c status firm, pink spoon-shaped, brittle, ridged, pale iron status regular heart rhythm, heart rate, and blood pressure; no impairment of digestive function, re exes, or mental status muscles and bones muscle tone; posture, long bone development appropriate for age abnormal heart rate, heart rhythm, or blood pressure; enlarged liver, spleen; abnormal digestion; burning, tingling of hands, feet; loss of balance, coordination; mental confusion, irritability, fatigue wasted appearance of muscles; swollen bumps on skull or ends of bones; small bumps on ribs; bowed legs or knock-knees pem and mineral status pem, mineral, and vitamin d status urine samples, which contain nutrients, enzymes, and metabolites that re ect nu- trition status. -other tests, such as serum glucose, help pinpoint disease-related problems with nutrition implications. -tests that de ne uid and electrolyte balance, acid-base balance, and organ function also have nutrition implications. -table e-6 (p. e-18) lists biochemical tests most useful for assessing vitamin and mineral status. -the interpretation of biochemical data requires skill. -long metabolic sequences lead to the production of the end products and metabolites seen in blood and urine. -no single test can reveal nutrition status because many factors in uence test results. -the low blood concentration of a nutrient may re ect a primary de ciency of that nutrient, but it may also be secondary to the de - ciency of one or several other nutrients or to a disease. -taken together with other assessment data, however, laboratory test results help to create a picture that becomes clear with careful interpretation. -they are especially useful in helping to detect subclinical malnutrition by uncovering early signs of malnu- trition before the clinical signs of a classic de ciency disease appear. -laboratory tests used to assess vitamin and mineral status (review table e-6) are particularly useful when combined with diet histories and physical ndings. -vitamin and mineral levels present in the blood and urine sometimes re ect re- cent rather than long-term intakes. -this makes detecting subclinical de ciencies dif cult. -furthermore, many nutrients interact; therefore, the amounts of other nutrients in the body can affect a lab value for a particular nutrient. -it is also im- portant to remember that nonnutrient conditions such as diseases in uence bio- chemical measures. -it is beyond the scope of this text to describe all lab tests and their relations to nutrition status. -instead, the emphasis is on lab tests used to detect protein-energy malnutrition (pem) and nutritional anemias. -protein-energy malnutrition (pem) no single biochemical analysis can adequately evaluate pem. -numerous proce- dures have been used over the years. -this discussion focuses on the measures com- monly used today transthyretin, retinol-binding protein, serum transferrin, and the serum is the watery portion of the blood that remains after removal of the cells and clot-forming material; plasma is the uid that remains when unclotted blood is centrifuged. -in most cases, serum and plasma concentrations are similar, but plasma samples are more likely to clog mechanical blood analyz- ers, so serum samples are preferred. -e a p p e n d i x reminder: a subclinical de ciency is a nutri- ent de ciency in the early stages before the outward signs have appeared. -e-18 appendix e e x i d n e p p a transthyretin is also known as prealbu- min or thyroxine-binding prealbumin. -table e-6 biochemical tests useful for assessing vitamin and mineral status nutrient assessment tests vitamins vitamin a thiamina ribo avina vitamin b6 a niacin folateb b vitamin b12 biotin vitamin c vitamin d vitamin e vitamin k minerals serum retinol, retinol-binding protein erythrocyte (red blood cell) transketolase activity, erythrocyte thiamin pyrophosphate erythrocyte glutathione reductase activity urinary xanthurenic acid excretion after tryptophan load test, erythrocyte transaminase activity, plasma pyridoxal 5(cid:4)-phosphate (plp) plasma or urinary metabolites nmn (n-methyl nicotinamide) or 2-pyridone, or preferably both expressed as a ratio serum folate, erythrocyte folate (re ects liver stores) serum vitamin b12, serum and urinary methylmalonic acid, schilling test urinary biotin, urinary 3-hydroxyisovaleric acid plasma vitamin cc, leukocyte vitamin c serum vitamin d serum (cid:5)-tocopherol, erythrocyte hemolysis serum vitamin k, plasma prothrombin; blood-clotting time (prothrombin time) is not an adequate indicator phosphorus serum phosphate sodium chloride potassium serum sodium serum chloride serum potassium magnesium serum magnesium, urinary magnesium iron iodine zinc copper selenium hemoglobin, hematocrit, serum ferritin, total iron-binding capacity (tibc), erythrocyte protoporphyrin, serum iron, transferrin saturation serum thyroxine or thyroid-stimulating hormone (tsh), urinary iodine plasma zinc, hair zinc erythrocyte superoxide dismutase, serum copper, serum ceruloplasmin erythrocyte selenium, glutathione peroxidase activity aurinary measurements for these vitamins are common, but may be of limited use. -urinary measurements re ect recent dietary intakes and may not provide reliable information concerning the severity of a de ciency. -bfolate assessments should always be conducted in conjunction with vitamin b12 assessments (and vice versa) to help distin- guish the cause of common de ciency symptoms. -cvitamin c shifts between the plasma and the white blood cells known as leukocytes; thus a plasma determination may not accurately re ect the body s pool. -a measurement of leukocyte vitamin c can provide information about the body s stores of vitamin c. a combination of both tests may be more reliable than either one alone. -source: adapted from h. e. sauberlich, laboratory tests for the assessment of nutritional status (boca raton, fla.: crc press, 1999). -igf-1 (insulin-like growth factor 1). -table e-7 provides standards for these indicators. -although serum albumin is easily and routinely measured, it lacks the sensitivity to assess pem because of its long turnover rate. -* transthyretin and retinol-binding protein transthyretin and retinol- binding protein occur as a complex in the plasma. -they have a rapid turnover and thus respond quickly to dietary protein inadequacy and therapy. -conditions other than malnutrition that lower transthyretin include metabolic stress, hemodialysis, and hypothyroidism; those that raise transthyretin include kidney disease and corti- costeroid use. -conditions other than protein malnutrition that lower retinol-binding protein include vitamin a de ciency, metabolic stress, hyperthyroidism, liver disease, and cystic brosis; kidney disease raises retinol-binding protein levels. -*the half-life of albumin is 18 days, an indication of a slow degradation rate. -the half-lives of transthyretin and retinol-binding protein are 2 days and 12 hours, respectively. -nutrition assessment e-19 e a p p e n d i x stages of iron de ciency: 1. iron stores diminish. -2. transport iron decreases. -3. hemoglobin production falls. -table e-7 normal values for serum proteins indicator albumin (g/dl) transferrin (mg/dl) transthyretin (mg/dl) retinol-binding protein (mg/dl) igf-1 ((cid:6)g/l) normal 3.5 5.4 200 400 23 43 3 7 300 note: levels less than normal suggest compromised protein status. -serum transferrin serum transferrin transports iron; consequently, its concentra- tions re ect both protein and iron status. -using transferrin as an indicator of protein status is complicated when an iron de ciency is present. -transferrin rises as iron de - ciency grows worse and falls as iron status improves. -markedly reduced transferrin levels indicate severe pem; in mild-to-moderate pem, transferrin levels may vary, lim- iting their usefulness. -conditions other than protein malnutrition that lower transfer- rin include liver disease, kidney disease, and metabolic stress; those that raise transferrin include pregnancy, iron de ciency, hepatitis, blood loss, and oral contra- ceptive use. -although transferrin breaks down in the body more quickly than albu- min, it is still relatively slow to respond to changes in protein intake and is not a sensitive indicator of the response to therapy. -* igf-1 (insulin-like growth factor 1) de- igf-1 (insulin-like growth factor 1) clines in pem. -igf-1 has a relatively short half-life and responds speci cally to dietary protein rather than energy. -for these reasons, it is a sensitive indicator of protein sta- tus and response to therapy. -conditions that decrease igf-1 include anorexia nervosa, in ammatory bowel disease, celiac disease, hiv infection, and fasting. -nutritional anemias anemia, a symptom of a wide variety of nutrition- and nonnutrition-related disor- ders, is characterized by a reduced number of red blood cells. -iron, folate, and vita- min b12 de ciencies caused by inadequate intake, poor absorption, or abnormal metabolism of these nutrients are the most common nutritional anemias. -some nonnutrition-related causes of anemia include massive blood loss, infections, hered- itary blood disorders such as sickle-cell anemia, and chronic liver or kidney disease. -assessment of iron-de ciency anemia iron de ciency, a common mineral de ciency, develops in stages. -chapter 13 describes iron de ciency in detail. -this section describes tests used to uncover iron de ciency as it progresses. -table e-8 (p. e-20) shows which laboratory tests detect various nutrition-related anemias, and table e-9 (p. e-21) provides values used for assessing iron status. -although other tests are more speci c in detecting early de - ciencies, hemoglobin and hematocrit are the commonly available tests. -hemoglobin iron forms an integral part of the hemoglobin molecule that trans- ports oxygen to the cells. -in iron de ciency, the body cannot synthesize hemoglobin. -low hemoglobin values signal depleted iron stores. -table e-9 provides hemoglobin values used in nutrition assessment. -hemoglobin s usefulness in evaluating iron sta- tus is limited, however, because hemoglobin concentrations drop fairly late in the *the half-life of transferrin is 8 days. -the half-life of igf-1 is 12 to 15 hours. -e-20 appendix e e x i d n e p p a table e-8 laboratory tests useful in evaluating nutrition-related anemias test or test result what it re ects for anemia (general) hemoglobin (hg) hematocrit (hct) total amount of hemoglobin in the red blood cells (rbc) percentage of rbc in the total blood volume red blood cell (rbc) count number of rbc mean corpuscular volume (mcv) mean corpuscular hemoglobin concentration (mchc) bone marrow aspiration for iron-de ciency anemia serum ferritin transferrin saturation rbc size; helps to determine if anemia is microcytic (iron de ciency) or macrocytic (folate or vitamin b12 de - ciency) hemoglobin concentration within the average rbc; helps to determine if anemia is hypochromic (iron de - ciency) or normochromic (folate or vitamin b12 de ciency) the manufacture of blood cells in different developmental states early de ciency state with depleted iron stores progressing de ciency state with diminished transport iron erythrocyte protoporphyrin later de ciency state with limited hemoglobin production for folate-de ciency anemia serum folate rbc folate for vitamin b12 de ciency anemia serum vitamin b12 schilling test progressing de ciency state later de ciency state progressing de ciency state absorption of vitamin b12 development of iron de ciency, and other nutrient de ciencies and medical condi- tions can also alter hemoglobin concentrations. -hematocrit hematocrit is commonly used to diagnose iron de ciency, even though it is an inconclusive measure of iron status. -to measure the hematocrit, a clinician spins a volume of blood in a centrifuge to separate the red blood cells from the plasma. -the hematocrit is the percentage of red blood cells in the total blood volume. -table e-9 includes values used to assess hematocrit status. -low values indicate in- complete hemoglobin formation, which is manifested by microcytic (abnormally small-celled), hypochromic (abnormally lacking in color) red blood cells. -low hemoglobin and hematocrit values alert the assessor to the possibility of iron deficiency. -however, many nutrients and other conditions can affect hemoglobin and hematocrit. -the other tests of iron status help pinpoint true iron de ciency. -serum ferritin in the rst stage of iron de ciency, iron stores diminish. -measures of serum ferritin provide an estimate of iron stores. -such information is most valuable to iron assessment. -table e-9 shows serum ferritin cutoff values that indicate iron store depletion in children and adults. -serum ferritin is not reliable for diagnosing iron de- ciency in infants, since normal serum ferritin values are often present in conjunction with iron-responsive anemia. -a decrease in transport iron characterizes the second stage of iron de ciency. -this is revealed by an increase in the iron-binding capacity of the protein trans- ferrin and a decrease in serum iron. -these changes are re ected by the transferrin saturation, which is calculated from the ratio of the other two values as described in the following paragraphs. -total iron-binding capacity (tibc) iron travels through the blood bound to the protein transferrin. -tibc is a measure of the total amount of iron that transferrin can nutrition assessment e-21 e a p p e n d i x table e-9 criteria for assessing iron status test hemoglobin (g/dl) hematocrit (%) serum ferritin ((cid:6)g/l) total iron-binding capacity ((cid:6)g/dl) serum iron ((cid:6)g/dl) transferrin saturation (%) erythrocyte protoporphyrin ((cid:6)g/dl rbc) age (yr) gender de ciency value 0.5 10 11 15 (cid:9)15 pregnancy 0.5 4 5 10 11 15 (cid:9)15 0.5 15 (cid:9)15 (cid:9)15 (cid:9)15 0.5 4 5 10 (cid:9)10 0.5 4 (cid:9)4 m f m f m f m f m f m f m f m f m f m f m f m f m f m f m f m f (cid:8)11 (cid:8)12 (cid:8)11.5 (cid:8)13 (cid:8)12 (cid:8)11 (cid:8)32 (cid:8)33 (cid:8)35 (cid:8)34 (cid:8)40 (cid:8)36 (cid:8)10 (cid:8)12 (cid:9)400 (cid:8)60 (cid:8)12 (cid:8)14 (cid:8)16 (cid:9)80 (cid:9)70 carry. -lab technicians measure iron-binding capacity directly. -table e-9 includes the cutoff for tibc. -serum iron lab technicians can also measure serum iron directly. -elevated values indicate iron overload; reduced values indicate iron de ciency. -table e-9 shows the de- cient value for serum iron. -transferrin saturation the percentage of transferrin that is saturated with iron is an indirect measure that is derived from the serum iron and total iron-binding capacity measures as follows: %transferrin (cid:2) serum iron total iron-binding capacity (cid:7) 100 table e-9 shows de cient transferrin saturation values for various age groups. -the third stage of iron de ciency occurs when the supply of transport iron di- minishes to the point that it limits hemoglobin production. -it is characterized by increases in erythrocyte protoporphyrin, a decrease in mean corpuscular volume, and decreased hemoglobin and hematocrit. -erythrocyte protoporphyrin the iron-containing portion of the hemoglobin mol- ecule is heme. -heme is a combination of iron and protoporphyrin. -protoporphyrin ac- cumulates in the blood when iron supplies are inadequate for the formation of heme. -lab technicians can measure erythrocyte protoporphyrin directly in a blood sample. -the cutoffs for abnormal values of erythrocyte protoporphyrin are shown in table e 9. mean corpuscular volume (mcv) a direct or calculated measure of the mean corpuscular volume (mcv) determines the average size of a red blood cell. -such a measure helps to classify the type of nutrient anemia. -in iron de ciency, the red blood cells are smaller than average. -e-22 appendix e e x i d n e p p a assessment of folate and vitamin b12 anemias folate de ciency and vitamin b12 de ciency present a similar clinical picture an anemia characterized by abnormally large red blood cell precursors (megaloblasts) in the bone marrow and abnormally large, mature red blood cells (macrocytic cells) in the blood. -distinguishing between these two de ciencies is particularly important because their treatments differ. -giving folate to a person with vitamin b12 de ciency improves many of the lab test results indicative of vitamin b12 de ciency, but this is a dangerous error because vitamin b12 de ciency causes nerve damage that folate can- not correct. -thus inappropriate folate administration masks vitamin b12 de ciency anemia, and nerve damage worsens. -for this reason, it is critical to determine whether the anemia results from a folate de ciency or from a vitamin b12 de ciency. -the fol- lowing biochemical assessment techniques help to make this distinction. -mean corpuscular volume (mcv) as previously mentioned, the mcv is a mea- sure of red blood cell size. -in folate and vitamin b12 de ciencies, the red blood cells are larger than average (macrocytic). -additional tests must be performed to differentiate folate from vitamin b12 de ciency. -folate levels serum folate levels uctuate with changes in folate intake and me- tabolism. -thus serum folate concentrations re ect current status, but provide little in- formation about folate stores. -as folate de ciency progresses and low serum levels persist, folate stores decline, resulting in folate depletion. -folate depletion is charac- terized by a fall in the folate concentrations of red blood cells (erythrocytes). -as ery- throcyte folate levels diminish, folate-de ciency anemia develops. -because low erythrocyte folate concentrations also occur with vitamin b12 de ciency, serum vita- min b12 concentrations must also be measured. -table e-10 shows standards for folate assessment. -vitamin b12 levels serum and urinary methylmalonic acid are elevated in vita- min b12 de ciency, but not in folate de ciency. -thus this measure is useful in distin- guishing between the two. -vitamin b12 de ciency usually arises from malabsorption. -to determine whether malabsorption is the cause, a small oral dose of vitamin b12 is given, and urinary excretion is measured. -this procedure measures vitamin b12 ab- sorption and is called a schilling test. -early stages of vitamin b12 de ciency can be detected by a low percentage sat- uration of its transport protein, a measure similar to iron s transferrin saturation. -as the de ciency progresses, serum vitamin b12 concentrations fall. -table e-10 shows standards for vitamin b12 assessment. -cautions about nutrition assessment to give all the details of nutrition assessment procedures would entail writing an- other textbook. -nevertheless, any student of nutrition should know the basics of a proper nutrition assessment procedure for two reasons. -table e-10 criteria for assessing folate and vitamin b12 de cient borderline acceptable serum folate (ng/ml) erythrocyte folate (ng/ml) serum vitamin b12 (pg/ml) serum methylmalonic acid (nmol/l) (cid:8)3.0 (cid:8)140 (cid:8)150 (cid:8)376 3.0 5.9 140 159 150 200 (cid:9)6.0 (cid:9)160 (cid:10)201 note: a nanogram (ng) is one-billionth of a gram; a picogram (pg) is one-trillionth of a gram. -nutrition assessment e-23 e a p p e n d i x first, competent medical care includes attention to nutrition. -physicians should either employ a person skilled in nutrition assessment techniques or refer all clients to such a person to ensure the sound nutrition health of their clients. -health care facilities should make nutrition assessment a routine part of the ini- tial workup on every client so that poor nutrition will not hinder the response to medical treatment and the recovery from illness. -second, because nutrition is such a popular subject today, fraudulent practices are even more abundant than they have been in the past (and they have always been rampant). -the knowledgeable consumer needs to know what procedures to expect in a nutrition assessment and what kinds of information they yield. -this appendix has presented the basics of nutrition assessment for these reasons. -this caution is added: the tests outlined here yield information that becomes meaningful only when integrated into a whole picture by a skilled, experienced, and educated interpreter. -potential sources of error are many, from the taking of the initial data to their reporting and analysis. -each assessment method and mea- sure is useful only as a part of the whole to con rm or eliminate the possibility of suspected nutrition problems. -for example, the assessor must constantly remem- ber that a suf cient intake of a nutrient does not guarantee adequate nutrient sta- tus for an individual. -conversely, the apparent inadequate intake of a nutrient does not, by itself, establish that a de ciency exists. -similarly, many uncertainties, such as the calibration of the equipment, the skills of the measurer, and the perspective of the interpreter, limit the accuracy and value of anthropometric measures. -this is also true of the results of the phys- ical examination. -physical signs suggestive of malnutrition are nonspeci c: they can re ect nutrient de ciencies or may be totally unrelated to nutrition. -assessors must interpret physical ndings in light of other assessment ndings. -finally, the usefulness of biochemical tests is also limited; the assessor must use caution in in- terpreting results. -vitamin and mineral blood concentrations may re ect disease processes, abnormal hormone levels, or other aberrations rather than dietary in- take. -even if concentrations do re ect dietary intake, they may re ect what the person has been eating recently and not give a true picture of the person s nutri- ent status. -such complications sometimes make it dif cult to detect a subclinical de ciency. -furthermore, many nutrients interact. -the assessor has to keep in mind that an abnormal lab value for one nutrient may re ect abnormal status of other nutrients. -the nal diagnosis is therefore appropriately tentative, and its con r- mation comes only after careful remedial steps successfully alleviate the observed problems. -references 1. v. a. hughes and coauthors, anthropomet- ric assessment of 10 y changes in body composition in the elderly, american journal of clinical nutrition 80 (2004): 475 482. -2. g. sun and coauthors, comparison of multifrequency bioelectrical impedance analysis with dual-energy x-ray absorp- tiometry for assessment of percentage body fat in a large, healthy population, american journal of clinical nutrition 81 (2005): 74 78. this page intentionally left blank physical activity and energy requirements f-1 contents calculating physical activity level estimating physical activity level using a shortcut to estimate total energy expenditure f a p p e n d i x physical activity and energy requirements chapter 8 described how to calculate estimated energy requirements (eer) for adults by using an equation that accounts for gender, age, weight, height, and physical activity level. -table f-1 presents additional equations to determine the eer for infants, children, adolescents, and pregnant and lactating women. -this appendix helps you determine the correct physical activity (pa) factor to use in the equations, either by calculating the physical activity level or by estimat- ing it. -for those who prefer to bypass these steps, the appendix presents tables that provide a shortcut to estimating total energy expenditure. -* calculating physical activity level to calculate your physical activity level, record all of your activities for a typical 24-hour day, noting the type of activity, the level of intensity, and the duration. -then, using a copy of table f-2, nd your activity in the rst column (or an activ- ity that is reasonably similar) and multiply the number of minutes spent on that activity by the factor in the third column. -put your answer in the last column and total the accumulated values for the day. -now add the subtotal of the last column to 1.1 (to account for basal energy and the thermic effect of food) as shown. -this score indicates your physical activity level. -using table f-3, nd the pa factor for your age and gender that correlates with your physical activity level and use it in the energy equations presented in table f-1. -estimating physical activity level as an alternative to recording your activities for a day, you can use the third column of table f-3 to decide if your daily activity is sedentary, low active, active, or very ac- tive. -find the pa factor for your age and gender that correlates with your typical physical activity level and use it in the energy equations presented in table f-1. -using a shortcut to estimate total energy expenditure the dri committee has developed estimates of total energy expenditure based on the equations for adults presented in table f-1. -these estimates are presented in table f-4 for women and table f-5 for men. -you can use these tables to estimate your energy requirement that is, the number of kcalories needed to maintain your current body weight. -on the table appropriate for your gender, nd your height in meters (or inches) in the left-hand column. -then follow the row across to nd your weight in kilograms (or pounds). -(if you can t nd your exact height and weight, choose a value between the two closest ones.) -look down the column to nd the number of kcalories that corresponds to your activity level. -importantly, the values given in the tables are for 30-year-old people. -women 19 to 29 should add 7 kcalories per day for each year below age 30; older women should subtract 7 kcalories per day for each year above age 30. similarly, men 19 to 29 should add 10 kcalories per day for each year below age 30; older men should subtract 10 kcalories per day for each year above age 30. -*this appendix, including the tables, is adapted from committee on dietary reference intakes, dietary reference intakes for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (washington, d.c.: national academies press, 2002/2005). -f-2 appendix f table f-1 equations to determine estimated energy requirement (eer) infants 0 3 months 4 6 months 7 12 months 13 15 months children and adolescents eer (cid:2) (89 (cid:3) weight (cid:4) 100) (cid:5) 175 eer (cid:2) (89 (cid:3) weight (cid:4) 100) (cid:5) 56 eer (cid:2) (89 (cid:3) weight (cid:4) 100) (cid:5) 22 eer (cid:2) (89 (cid:3) weight (cid:4) 100) (cid:5) 20 boys 3 8 years 9 18 years girls 3 8 years 9 18 years adults men women pregnancy 1st trimester 2nd trimester 3rd trimester lactation eer (cid:2) 88.5 (cid:4) (61.9 (cid:3) age (cid:5) pa (cid:3) [(26.7 (cid:3) weight) (cid:5) (903 (cid:3) height)] + 20 eer (cid:2) 88.5 (cid:4) (61.9 (cid:3) age (cid:5) pa (cid:3) [(26.7 (cid:3) weight) (cid:5) (903 (cid:3) height)] + 25 eer (cid:2) 135.3 (cid:4) (30.8 (cid:3) age (cid:5) pa (cid:3) [(10.0 (cid:3) weight) (cid:5) (934 (cid:3) height)] + 20 eer (cid:2) 135.3 (cid:4) (30.8 (cid:3) age (cid:5) pa (cid:3) [(10.0 (cid:3) weight) (cid:5) (934 (cid:3) height)] + 25 eer (cid:2) 662 (cid:4) (9.53 (cid:3) age (cid:5) pa (cid:3) [(15.91 (cid:3) weight) (cid:5) (539.6 (cid:3) height)] eer (cid:2) 354 (cid:4) (6.91 (cid:3) age (cid:5) pa (cid:3) [(9.36 (cid:3) weight) (cid:5) (726 (cid:3) height)] eer (cid:2) nonpregnant eer (cid:5) 0 eer (cid:2) nonpregnant eer (cid:5) 340 eer (cid:2) nonpregnant eer (cid:5) 452 0 6 months postpartum 7 12 months postpartum eer (cid:2) nonpregnant eer (cid:5) 500 (cid:4) 170 eer (cid:2) nonpregnant eer (cid:5) 400 (cid:4) 0 note: select the appropriate equation for gender and age and insert weight in kilograms, height in meters, and age in years. -see the text and table f-3 to determine pa. table f-2 physical activities and their scores f x i d n e p p a if your activity was equivalent to this activities of daily living gardening (no lifting) household tasks (moderate effort) lifting items continuously loading/unloading car lying quietly mopping mowing lawn (power mower) raking lawn riding in a vehicle sitting (idle) sitting (doing light activity) taking out trash vacuuming walking the dog walking from house to car or bus watering plants additional activities billiards calisthenics (no weight) canoeing (leisurely) chopping wood then list the number of minutes here and multiply by this factor add this column to get your physical activity level score: 0.0032 0.0024 0.0029 0.0019 0.0000 0.0024 0.0033 0.0029 0.0000 0.0000 0.0005 0.0019 0.0024 0.0019 0.0014 0.0014 0.0013 0.0029 0.0014 0.0037 continued table f-2 physical activities and their scores continued if your activity was equivalent to this then list the number of minutes here and multiply by this factor add this column to get your physical activity level score: physical activity and energy requirements f-3 additional activities continued climbing hills (carrying 11 lb load) climbing hills (no load) cycling (leisurely) cycling (moderately) dancing (aerobic or ballet) dancing (ballroom, leisurely) dancing (fast ballroom or square) golf (with cart) golf (without cart) horseback riding (walking) horseback riding (trotting) jogging (6 mph) music (playing accordion) music (playing cello) music (playing ute) music (playing piano) music (playing violin) rope skipping skating (ice) skating (roller) skiing (water or downhill) squash sur ng swimming (slow) swimming (fast) tennis (doubles) tennis (singles) volleyball (noncompetitive) walking (2 mph) walking (3 mph) walking (4 mph) walking (5 mph) subtotal factor for basal energy and the thermic effect of food your physical activity level score table f-3 physical activity equivalents and their pa factors physical activity level description 1.0 to 1.39 sedentary 1.4 to 1.59 low active 1.6 to 1.89 active 1.9 and above very active physical activity equivalents only those physical activities required for typical daily living daily living + 30 60 min moderate activitya daily living + (cid:6) 60 min moderate activity daily living + (cid:6) 60 min moderate activity and (cid:6) 60 min vigorous activity or (cid:6) 120 min moderate activity amoderate activity is equivalent to walking at a pace of 3 to 41/2 mph. -0.0061 0.0056 0.0024 0.0045 0.0048 0.0018 0.0043 0.0014 0.0032 0.0012 0.0053 0.0088 0.0008 0.0012 0.0010 0.0012 0.0014 0.0105 0.0043 0.0052 0.0055 0.0106 0.0048 0.0033 0.0057 0.0038 0.0057 0.0018 0.0014 0.0022 0.0033 0.0067 1.1 f a p p e n d i x men, 19+ yr women, 19+ yr boys, 3 18 yr girls, 3 18 yr pa factor pa factor pa factor pa factor 1.0 1.11 1.25 1.48 1.0 1.12 1.27 1.45 1.0 1.13 1.26 1.42 1.0 1.16 1.31 1.56 f-4 appendix f table f-4 of activity and various heights and weights total energy expenditure (tee in kcalories per day) for women 30 years of agea at various levels heights m (in) 1.45 (57) physical activity level 38.9 (86) 45.2 (100) 52.6 (116) 63.1 (139) 73.6 (162) 84.1 (185) weightb kg (lb) sedentary low active active very active 1564 1734 1946 2201 1623 1800 2021 2287 kcalories 1698 1912 2112 2387 1813 2043 2257 2553 1927 2174 2403 2719 2042 2304 2548 2886 1.50 (59) 41.6 (92) 48.4 (107) 56.3 (124) 67.5 (149) 78.8 (174) 90.0 (198) sedentary low active active very active 1625 1803 2025 2291 1689 1874 2105 2382 kcalories 1771 1996 2205 2493 1894 2136 2360 2671 2017 2276 2516 2849 2139 2415 2672 3027 1.55 (61) 44.4 (98) 51.7 (114) 60.1 (132) 72.1 (159) 84.1 (185) 96.1 (212) sedentary low active active very active 1688 1873 2104 2382 1756 1949 2190 2480 kcalories 1846 2081 2299 2601 1977 2230 2466 2791 2108 2380 2632 2981 2239 2529 2798 3171 1.60 (63) 47.4 (104) 55.0 (121) 64.0 (141) 76.8 (169) 89.6 (197) 102.4 (226) sedentary low active active very active 1752 1944 2185 2474 1824 2025 2276 2578 kcalories 1922 2168 2396 2712 2061 2327 2573 2914 2201 2486 2750 3116 2340 2645 2927 3318 1.65 (65) 50.4 (111) 58.5 (129) 68.1 (150) 81.7 (180) 95.3 (210) 108.9 (240) sedentary low active active very active 1816 2016 2267 2567 1893 2102 2364 2678 kcalories 1999 2556 2494 2824 2148 2425 2682 3039 2296 2594 2871 3254 2444 2763 3059 3469 1.70 (67) 53.5 (118) 62.1 (137) 72.3 (159) 86.7 (191) 101.2 (223) 115.6 (255) f x i d n e p p a sedentary low active active very active 1881 2090 2350 2662 1963 2180 2453 2780 kcalories 2078 2345 2594 2938 2235 2525 2794 3166 2393 2705 2994 3395 2550 2884 3194 3623 1.75 (69) 56.7 (125) 65.8 (145) 76.6 (169) 91.9 (202) 107.2 (236) 122.5 (270) sedentary low active active very active 1948 2164 2434 2758 2034 2260 2543 2883 kcalories 2158 2437 2695 3054 2325 2627 2907 3296 2492 2817 3119 3538 2659 3007 3331 3780 1.80 (71) 59.9 (132) 69.7 (154) 81.0 (178) 97.2 (214) 113.4 (250) 129.6 (285) sedentary low active active very active 2015 2239 2519 2855 2106 2341 2634 2987 kcalories 2239 2529 2799 3172 2416 2731 3023 3428 2593 2932 3247 3684 2769 3133 3472 3940 continued afor each year below 30, add 7 kcalories/day to tee. -for each year above 30, subtract 7 kcalories/day from tee. -bthese columns represent a bmi of 18.5, 22.5, 25, 30, 35, and 40, respectively. -physical activity and energy requirements f-5 table f-4 of activity and various heights and weights continued total energy expenditure (tee in kcalories per day) for women 30 years of agea at various levels heights m (in) 1.85 (73) physical activity level 63.3 (139) 73.6 (162) 85.6 (189) 102.7 (226) 119.8 (264) 136.9 (302) weightb kg (lb) sedentary low active active very active 2083 2315 2605 2954 2179 2422 2727 3093 kcalories 2322 2624 2904 3292 2509 2836 3141 3562 2695 3049 3378 3833 2882 3262 3615 4103 1.90 (75) 66.8 (147) 77.6 (171) 90.3 (199) 108.3 (239) 126.4 (278) 144.4 (318) sedentary low active active very active 2151 2392 2693 3053 2253 2505 2821 3200 kcalories 2406 2720 3011 3414 2603 2944 3261 3699 2800 3168 3511 3984 2996 3393 3760 4270 1.95 (77) 70.3 (155) 81.8 (180) 95.1 (209) 114.1 (251) 133.1 (293) 152.1 (335) sedentary low active active very active 2221 2470 2781 3154 2328 2589 2917 3309 kcalories 2492 2817 3119 3538 2699 3053 3383 3838 2906 3290 3646 4139 3113 3526 3909 4439 afor each year below 30, add 7 kcalories/day to tee. -for each year above 30, subtract 7 kcalories/day from tee. -bthese columns represent a bmi of 18.5, 22.5, 25, 30, 35, and 40, respectively. -table f-5 of activity and various heights and weights total energy expenditure (tee in kcalories per day) for men 30 years of agea at various levels heights m (in) 1.45 (57) physical activity level 38.9 (86) 47.3 (100) 52.6 (116) 63.1 (139) 73.6 (163) 84.1 (185) weightb kg (lb) sedentary low active active very active 1777 1931 2127 2450 1911 2080 2295 2648 kcalories 2048 2225 2447 2845 2198 2393 2636 3075 2347 2560 2826 3305 2496 2727 3015 3535 1.50 (59) 41.6 (92) 50.6 (107) 56.3 (124) 67.5 (149) 78.8 (174) 90.0 (198) sedentary low active active very active 1848 2009 2215 2554 1991 2168 2394 2766 kcalories 2126 2312 2545 2965 2286 2491 2748 3211 2445 2670 2951 3457 2605 2849 3154 3703 1.55 (61) 44.4 (98) 54.1 (114) 60.1 (132) 72.1 (159) 84.1 (185) 96.1 (212) f a p p e n d i x sedentary low active active very active 1919 2089 2305 2660 2072 2259 2496 2887 kcalories 2205 2401 2646 3087 2376 2592 2862 3349 2546 2783 3079 3612 2717 2974 3296 3875 continued afor each year below 30, add 10 kcalories/day to tee. -for each year above 30, subtract 10 kcalories/day from tee. -bthese columns represent a bmi of 18.5, 22.5, 25, 30, 35, and 40, respectively. -f-6 appendix f table f-5 of activity and various heights and weights continued total energy expenditure (tee in kcalories per day) for men 30 years of agea at various levels heights m (in) 1.60 (63) physical activity level 47.4 (104) 57.6 (121) 64.0 (141) 76.8 (169) 89.6 (197) 102.4 (226) weightb kg (lb) sedentary low active active very active 1993 2171 2397 2769 2156 2351 2601 3010 kcalories 2286 2492 2749 3211 2468 2695 2980 3491 2650 2899 3210 3771 2831 3102 3441 4051 1.65 (65) 50.4 (111) 61.3 (129) 68.1 (150) 81.7 (180) 95.3 (210) 108.9 (240) sedentary low active active very active 2068 2254 2490 2880 2241 2446 2707 3136 kcalories 2369 2585 2854 3339 2562 2801 3099 3637 2756 3017 3345 3934 2949 3234 3590 4232 1.70 (67) 53.5 (118) 65.0 (137) 72.3 (159) 86.7 (191) 101.2 (223) 115.6 (255) sedentary low active active very active 2144 2338 2586 2992 2328 2542 2816 3265 kcalories 2454 2679 2961 3469 2659 2909 3222 3785 2864 3139 3483 4101 3069 3369 3743 4417 1.75 (69) 56.7 (125) 68.9 (145) 76.6 (169) 91.9 (202) 107.2 (236) 122.5 (270) sedentary low active active very active 2222 2425 2683 3108 2416 2641 2927 3396 kcalories 2540 2776 3071 3602 2757 3020 3347 3937 2975 3263 3623 4272 3192 3507 3900 4607 1.80 (71) 59.9 (132) 72.9 (154) 81.0 (178) 97.2 (214) 113.4 (250) 129.6 (285) sedentary low active active very active 2301 2513 2782 3225 2507 2741 3040 3530 kcalories 2628 2875 3183 3738 2858 3132 3475 4092 3088 3390 3767 4447 3318 3648 4060 4801 1.85 (73) 63.3 (139) 77.0 (162) 85.6 (189) 102.7 (226) 119.8 (264) 136.9 (302) sedentary low active active very active 2382 2602 2883 3344 2599 2844 3155 3667 kcalories 2718 2976 3297 3877 2961 3248 3606 4251 3204 3520 3915 4625 3447 3792 4223 4999 f x i d n e p p a 1.90 (75) 66.8 (147) 81.2 (171) 90.3 (199) 108.3 (239) 126.4 (278) 144.4 (318) sedentary low active active very active 2464 2693 2986 3466 2693 2948 3273 3806 kcalories 2810 3078 3414 4018 3066 3365 3739 4413 3322 3652 4065 4807 3579 3939 4390 5202 1.95 (77) 70.3 (155) 85.6 (180) 95.1 (209) 114.1 (251) 133.1 (293) 152.1 (335) sedentary low active active very active 2547 2786 3090 3590 2789 3055 3393 3948 kcalories 2903 3183 3533 4162 3173 3485 3875 4578 3443 3788 4218 4993 3713 4090 4561 5409 afor each year below 30, add 10 kcalories/day to tee. -for each year above 30, subtract 10 kcalories/day from tee. -bthese columns represent a bmi of 18.5, 22.5, 25, 30, 35, and 40, respectively. -united states: exchange lists g-1 united states: exchange lists chapter 2 introduced the exchange system, and this appendix provides details from the 2003 edition. -appendix i presents canada s meal planning system. -contents the exchange groups and lists combining food group plans and exchange lists the exchange groups and lists the exchange system sorts foods into three main groups by their proportions of car- bohydrate, fat, and protein. -these three groups the carbohydrate group, the fat group, and the meat and meat substitutes group (protein) organize foods into several exchange lists (see table g-1). -then any food on a list can be exchanged for any other on that same list. -the carbohydrate group covers these exchange lists: starch (cereals, grains, pasta, breads, crackers, snacks, starchy vegetables, and dried beans, peas, and lentils) fruit milk (fat-free, reduced fat, and whole) other carbohydrates (desserts and snacks with added sugars and fats) vegetables the fat group covers this exchange list: fats the meat and meat substitutes group (protein) covers these exchange lists: meat and meat substitutes (very lean, lean, medium-fat, and high-fat) table g-1 the exchange groups and lists group/lists carbohydrate group starchb fruit milk fat-free, low-fat reduced-fat whole other carbohydratesc vegetable (nonstarchy) meat and meat substitute group d meat very lean lean medium-fat high-fat fat group fat typical item/portion size carbohydrate (g) protein (g) fat (g) energya (kcal) 1 slice bread 1 small apple 1 c fat-free milk 1 c reduced-fat milk 1 c whole milk 2 small cookies 1 2 c cooked carrots 1 oz chicken (white meat, no skin) 1 oz lean beef 1 oz ground beef 1 oz pork sausage 1 tsp butter 15 15 12 12 12 15 5 3 8 8 8 varies 2 7 7 7 7 0 1 0 3 5 8 varies 0 1 3 5 8 5 80 60 90 120 150 varies 25 35 55 75 100 45 g a p p e n d i x athe energy value for each exchange list represents an approximate average for the group and does not re ect the precise number of grams of carbohydrate, protein, and fat. -for example, a slice of bread contains 15 grams of carbohydrate (that s 60 kcalories), 3 grams protein (that s another 12 kcalories), and a little fat rounded to 80 kcalories for ease in calculating. -a half-cup of vegetables (not including starchy vegetables) contains 5 grams carbohydrate (20 kcalories) and 2 grams protein (8 more), which has been rounded down to 25 kcalories. -bthe starch list includes cereals, grains, breads, crackers, snacks, starchy vegetables (such as corn, peas, and potatoes), and legumes (dried beans, peas, and lentils). -cthe other carbohydrates list includes foods that contain added sugars and fats such as cakes, cookies, doughnuts, ice cream, potato chips, pudding, syrup, and frozen yogurt. -dthe meat and meat substitutes list includes legumes, cheeses, and peanut butter. -g-2 appendix g figure g-1 food label seeing exchanges on a portion sizes knowing that foods on the starch list provide 15 grams of carbohydrate and those on the vegetable list provide 5, you can count a lasagna dinner that provides 37 grams of carbohydrate as 2 starches and 1 vegetable ; knowing that foods on the meat list provide 7 grams of protein, you might count it as 3 meats ; the grams of fat suggest that the meat (and cheese) is probably medium-fat. -nutrition facts serving size 101/2 oz (298 g) servings per package 1 amount per serving calories 361 calories from fat 117 % daily value 20% 40% 29% 36% 12% total fat 13 g saturated fat 8 g cholesterol 87 mg sodium 860 mg total carbohydrate 37 g dietary fiber 0 g sugars 8 g protein 26 g can you see these exchanges in the label above? -exchange carbohydrate protein fat 2 starches 1 vegetable 30 g 5 g 6 g 2 g 3 medium-fat meats 21 g 15 g exchange totals label totals 35 37 29 26 15 13 g x i d n e p p a the exchange system helps people control their energy intakes by paying close atten- tion to portion sizes. -the portion sizes have been carefully adjusted and de ned so that a portion of any food on a given list provides roughly the same amount of car- bohydrate, fat, and protein and, therefore, total kcalories. -any food on a list can then be exchanged, or traded, for any other food on that same list without signi cantly af- fecting the diet s balance or total kcalories. -for example, a person may select either 17 small grapes or 1 2 large grapefruit as one fruit exchange, and either choice would pro- vide roughly 60 kcalories. -a whole grapefruit, however, would count as 2 exchanges. -to apply the system successfully, users must become familiar with portion sizes. -a convenient way to remember the portion sizes and energy values is to keep in mind a typical item from each list (review table g-1). -the foods on the lists foods do not always appear on the exchange list where you might rst expect to nd them. -they are grouped according to their energy-nutrient contents rather than by their source (such as milks), their outward appearance, or their vitamin and mineral contents. -notice, for example, that cheeses are grouped with meats (not milk) because, like meats, cheeses contribute energy from protein and fat but provide negligible carbohydrate. -similarly, starchy vegetables such as pota- toes are found on the starch list with breads and cereals, not with the vegetables, and bacon is with the fats and oils, not with the meats. -diet planners learn to view mixtures of foods, such as casseroles and soups, as combinations of foods from different exchange lists. -they also learn to interpret food labels with the exchange system in mind (see figure g-1). -controlling energy and fat by assigning items like bacon to the fat list, the exchange system alerts con- sumers to foods that are unexpectedly high in fat. -even the starch list speci es which grain products contain added fat (such as biscuits, muf ns, and waf es). -in addition, the exchange system encourages users to think of fat-free milk as milk and of whole milk as milk with added fat, and to think of very lean meats as meats and of lean, medium-fat, and high-fat meats as meats with added fat. -to that end, foods on the milk and meat lists are separated into categories based on their fat contents. -the milk group is classed as fat-free, reduced-fat, and whole; the meat group as very lean, lean, medium-fat, and high-fat. -control of food energy and fat intake can be highly successful with the ex- change system. -exchange plans do not, however, guarantee adequate intakes of vitamins and minerals. -food group plans work better from that standpoint be- cause the food groupings are based on similarities in vitamin-mineral content. -in the exchange system, for example, meats are grouped with cheeses, yet the meats are iron-rich and calcium-poor, whereas the cheeses are iron-poor and calcium- rich. -to take advantage of the strengths of both food group plans and exchange patterns, and to compensate for their weaknesses, diet planners often combine these two diet-planning tools. -combining food group plans and exchange lists a person may nd that using a food group plan together with the exchange lists eases the task of choosing foods that provide all the nutrients. -the food group plan ensures that all classes of nutritious foods are included, thus promoting ade- quacy, balance, and variety. -the exchange system classi es the food selections by their energy-yielding nutrients, thus controlling energy and fat intakes. -united states: exchange lists g-3 table g-2 the usda food guide pattern diet planning with the exchange system using 2000-kcalorie diet plan using usda food guide selections made using the exchange system energy (kcal) grains (breads and cereals) 6 oz starch list select 6 exchanges vegetables 21/2 c vegetable list select 5 exchanges fruits 2 c meat 51/2 oz milk 3 c oils 6 tsp fruit list select 4 exchanges meat list select 51/2 lean exchanges milk list select 3 fat-free exchanges fat list select 6 exchanges discretionary kcalories total 480 125 240 300 270 270 267 1955 table g-2 shows how to use the usda food guide plan together with the ex- change lists to plan a diet. -the usda food guide ensures that a certain number of servings is chosen from each of the food groups (see the rst column of the table). -the second column translates the food groups into exchanges. -with the addition of a few discretionary kcalories, this sample diet plan provides abut 1955 kcalories. -most peo- ple can meet their needs for all the nutrients within this reasonable energy al- lowance. -the next step in diet planning is to assign the exchanges to meals and snacks. -the nal plan might look like the one in table g-3. -next, a person could begin to ll in the plan with real foods to create a menu (use tables g-4 through g-12). -for example, the breakfast plan calls for 1 starch exchange, 2 fruit exchanges, and 1 fat-free milk exchange. -a person might select a bowl of shredded wheat with banana slices and milk and a small glass of orange juice: 3 4 cup unsweetened, ready-to-eat cereal (cid:2) 1 starch exchange 1 small banana (cid:2) 1 fruit exchange 1 cup fat-free milk (cid:2) 1 milk exchange 1 2 cup orange juice (cid:2) 1 fruit exchange or half an english muf n and a bowl of fruit topped with yogurt: 1 2 english muf n (cid:2) 1 starch exchange 1 3 cantaloupe melon (cid:2) 1 fruit exchange 11 4 cup strawberries = 1 fruit exchange 2 3 cup fat-free plain yogurt (cid:2) 1 milk exchange table g-3 a sample diet plan and menu this diet plan is one of many possibilities. -it follows the number of servings suggested by the daily food guide and meets dietary recommendations to provide 45 to 65 percent of its kcalories from carbohydrate, 10 to 35 percent from protein, and 20 to 35 percent from fat. -exchange breakfast lunch snack dinner snack 6 starch 5 vegetables 4 fruit 51/2 lean meat 3 fat-free milk 6 fat 1 2 1 2 1 2 1 1 1 2 5 31/2 5 1 1 g a p p e n d i x s a m p l e m e n u breakfast: cereal with banana and milk, lunch: snack: dinner: orange juice turkey sandwich, milk, small bunch of grapes apple spaghetti with meat sauce; salad with sun ower seeds and dressing; green beans; corn on the cob snack: graham crackers and milk g-4 appendix g then the person could move on to complete the menu for lunch, dinner, and snacks. -(table g-3 includes a sample menu.) -as you can see, we all make countless food-related decisions daily whether we have a plan or not. -following a plan, like the usda food guide, that incorporates health recommendations and diet- planning principles helps a person to make wise decisions. -table g-4 u.s. exchange system: starch list 1 starch exchange (cid:2) 15 g carbohydrate, 3 g protein, 0 1 g fat, and 80 kcal note: in general, one starch exchange is 1 2 c cooked cereal, grain, or starchy vegetable; 1 3 c cooked rice or pasta; 1 oz of bread; 3 4 to 1 oz snack food. -serving size food serving size food bread 1 4 (1 oz) 2 slices (11 2 oz) 1 slice (1 oz) 4 (2 3 oz) 1 2 1 2 (1 oz) 1 4 1 1 2 1 (1 oz) 1 slice (1 oz) 1 1 1 3 1 cereals and grains bagel, 4 oz bread, reduced-kcalorie bread, white (including french and italian), whole- wheat, pumpernickel, rye bread sticks, crisp, 4(cid:3) x 1 2(cid:3) english muf n hot dog or hamburger bun naan, 8(cid:3) x 2(cid:3) pancake, 4(cid:3) across, 1 4(cid:3)thick pita, 6(cid:3) across plain roll, small raisin bread, unfrosted tortilla, corn, 6(cid:3) across tortilla, our, 6(cid:3) across tortilla, our, 10(cid:3) across waf e, 4(cid:3) square or across, reduced-fat 1 2 c 1 2 c 1 2 c 3 4 c 3 tbs 1 3 c 3 tbs 1 4 c 1 4 c 1 2 c 1 2 c 1 3 c 1 4 c 1 2 c 1 3 c 11 2 c 1 3 c 1 2 c 1 2 c 3 tbs g x i d n e p p a bran cereals bulgur, cooked cereals, cooked cereals, unsweetened, ready-to-eat cornmeal (dry) couscous flour (dry) granola, low-fat grape nuts grits, cooked kasha millet muesli oats pasta, cooked puffed cereals rice, white or brown, cooked shredded wheat sugar-frosted cereal wheat germ starchy vegetables 1 3 c 1 2 c 1 2 cob (5 oz) 1 c baked beans corn corn on cob, large mixed vegetables with corn, peas, or pasta (cid:2) 400 mg or more of sodium per serving. -1 2 c 1 2 c 1 2 medium (3 oz) or 1 2 c 1 4 large (3 oz) 1 2 c 1 c 1 2 c peas, green plantains potato, boiled potato, baked with skin potatoes, mashed squash, winter (acorn, butternut, pumpkin) yams, sweet potatoes, plain crackers and snacks 8 3 3 4 oz 4 slices 24 3 c 3 4 oz 2 6 15 20 (3 4 oz) 2 5 (3 4 oz) animal crackers graham crackers, 21 2(cid:3) square matzoh melba toast oyster crackers popcorn (popped, no fat added or low-fat microwave) pretzels rice cakes, 4(cid:3) across saltine-type crackers snack chips, fat-free or baked (tortilla, potato) whole-wheat crackers, no fat added beans, peas, and lentils (count as 1 starch (cid:2) 1 very lean meat) 1 2 c 2 3 c 3 tbs beans and peas, cooked (garbanzo, lentils, pinto, kidney, white, split, black-eyed) lima beans miso starchy foods prepared with fat (count as 1 starch (cid:2) 1 fat) 1 1 2 c 1 (2 oz) 6 1 c 1 c (2 oz) 1 4 c 1 3 c 1 5 (1 oz) 3 c 3 9 13 (3 4 oz) 1 3 c 2 1 4 6 (1 oz) biscuit, 21 2(cid:3) across chow mein noodles cornbread, 2(cid:3) cube crackers, round butter type croutons french-fried potatoes (oven baked) granola hummus muf n, 5 oz popcorn, microwave sandwich crackers, cheese or peanut butter lling snack chips (potato, tortilla) stuf ng, bread (prepared) taco shells, 6(cid:3) across waf e, 41 2(cid:3) square or across whole-wheat crackers, fat added table g-5 u.s. exchange system: fruit list 1 fruit exchange (cid:2) 15 g carbohydrate and 60 kcal note: in general, one fruit exchange is 1 small fresh fruit; 1 2 c canned or fresh fruit or unsweetened fruit juice; 1 4 c dried fruit. -serving size food serving size food united states: exchange lists g-5 1 (4 oz) 1 2 c 4 rings 4 whole (51 2 oz) 8 halves 1 2 c 1 (4 oz) 3 4 c 3 4 c 1 3 melon (11 oz) or 1 c cubes 12 (3 oz) 1 2 c 3 11 2 large or 2 medium (31 2 oz) 11 2 1 2 c 1 2 (11 oz) 3 4 c 17 (3 oz) 1 slice (10 oz) or 1 c cubes 1 (31 2 oz) 3 4 c 1 2 (51 2 oz) or 1 2 c 1 (5 oz) 1 (61 2 oz) apple, unpeeled, small applesauce, unsweetened apples, dried apricots, fresh apricots, dried apricots, canned banana, small blackberries blueberries cantaloupe, small cherries, sweet, fresh cherries, sweet, canned dates figs, fresh figs, dried fruit cocktail grapefruit, large grapefruit sections, canned grapes, small honeydew melon kiwi mandarin oranges, canned mango, small nectarine, small orange, small 1 2 (8 oz) or 1 c cubes 1 (4 oz) 1 2 c 1 2 (4 oz) 1 2 c 3 4 c 1 2 c 2 (5 oz) 1 2 c 3 2 tbs 1 c 11 4 c whole berries 2 (8 oz) 1 slice (131 2 oz) or 11 4 c cubes papaya peach, medium, fresh peaches, canned pear, large, fresh pears, canned pineapple, fresh pineapple, canned plums, small plums, canned plums, dried (prunes) raisins raspberries strawberries tangerines, small watermelon fruit juice, unsweetened 1 2 c 1 3 c 1 c 1 3 c 1 3 c 1 2 c 1 2 c 1 2 c 1 3 c apple juice/cider cranberry juice cocktail cranberry juice cocktail, reduced-kcalorie fruit juice blends, 100% juice grape juice grapefruit juice orange juice pineapple juice prune juice table g-6 u.s. exchange system: milk list note: in general, one milk exchange is 1 c milk or yogurt. -serving size food serving size food fat-free and low-fat milk 1 fat-free/low-fat milk exchange (cid:2) 12 g carbohydrate, 8 g protein, 0 3 g fat, 90 kcal 1 c 1 c 1 c 1 c 1 2 c 1 3 c dry 1 c 2 3 c (6 oz) fat-free milk 1 2% milk 1% milk fat-free or low-fat buttermilk evaporated fat-free milk fat-free dry milk soy milk, low-fat or fat-free yogurt, fat-free or low-fat, avored, sweetened with nonnutritive sweetener and fructose yogurt, plain fat-free 2 3 c (6 oz) reduced-fat milk 1 reduced-fat milk exchange (cid:2) 12 g carbohydrate, 8 g protein, 5 g fat, 120 kcal 1 c 1 c 1 c 3 4 c 2% milk soy milk sweet acidophilus milk yogurt, plain low-fat whole milk 1 whole milk exchange (cid:2) 12 g carbohydrate, 8 g protein, 8 g fat, 150 kcal 1 c 1 2 c 1 c 1 c 3 4 c whole milk evaporated whole milk goat s milk ke r yogurt, plain (made from whole milk) g a p p e n d i x g-6 appendix g table g-7 u.s. exchange system: sweets, desserts, and other carbohydrates list 1 other carbohydrate exchange (cid:2) 15 g carbohydrate, or 1 starch, or 1 fruit, or 1 milk exchange food angel food cake, unfrosted brownies, small, unfrosted cake, unfrosted cake, frosted cookies or sandwich cookies with creme lling cookies, sugar-free cranberry sauce, jellied cupcake, frosted doughnut, plain cake doughnut, glazed energy, sport, or breakfast bar energy, sport, or breakfast bar fruit cobbler fruit juice bar, frozen, 100% juice fruit snacks, chewy (pureed fruit concentrate) fruit spreads, 100% fruit gelatin, regular gingersnaps granola or snack bar, regular or low-fat honey ice cream ice cream, light ice cream, low-fat ice cream, fat-free, no sugar added jam or jelly, regular milk, chocolate, whole pie, fruit, 2 crusts pie, pumpkin or custard pudding, regular (made with reduced-fat milk) pudding, sugar-free (made with fat-free milk) reduced-calorie meal replacement (shake) rice milk, low-fat or fat-free, plain rice milk, low-fat, avored salad dressing, fat-free sherbet, sorbet spaghetti or pasta sauce, canned sports drinks sugar sweet roll or danish syrup, light syrup, regular syrup, regular vanilla wafers yogurt, frozen yogurt, frozen, fat-free yogurt, low-fat with fruit g x i d n e p p a (cid:2) 400 mg or more sodium per exchange. -serving size 1 12 cake (2 oz) 2(cid:3) square (1 oz) 2(cid:3) square (1 oz) 2(cid:3) square (2 oz) 2 small (2 3 oz) 3 small or 1 large (3 4 1 oz) 1 4 c 1 small (2 oz) 1 medium (11 2 oz) 33 4 across (2 oz) 1 bar (11 3 oz) 1 bar (2 oz) 1 2 c (31 2 oz) 1 bar (3 oz) 1 roll (3 4 oz) 11 2 tbs 1 2 c 3 1 bar (1 oz) 1 tbs 1 2 c 1 2 c 1 2 c 1 2 c 1 tbs 1 c 1 6 of 8(cid:3) commercially prepared pie 1 8 of 8(cid:3) commercially prepared pie 1 2 c 1 2 c 1 can (10 11 oz) 1 c 1 c 1 4 c 1 2 c 1 2 c 8 oz (1 c) 1 tbs 1 (21 2 oz) 2 tbs 1 tbs 1 4 c 5 1 2 c 1 3 c 1 c exchanges per serving 2 carbohydrates 1 carbohydrate, 1 fat 1 carbohydrate, 1 fat 2 carbohydrates, 1 fat 1 carbohydrate, 1 fat 1 carbohydrate, 1 2 fats 11 2 carbohydrates 2 carbohydrates, 1 fat 11 2 carbohydrates, 2 fats 2 carbohydrates, 2 fats 11 2 carbohydrates, 0 1 fat 2 carbohydrates, 1 fat 3 carbohydrates, 1 fat 1 carbohydrate 1 carbohydrate 1 carbohydrate 1 carbohydrate 1 carbohydrate 11 2 carbohydrates 1 carbohydrate 1 carbohydrate, 2 fats 1 carbohydrate, 1 fat 11 2 carbohydrates 1 carbohydrate 1 carbohydrate 2 carbohydrates, 1 fat 3 carbohydrates, 2 fats 2 carbohydrates, 2 fats 2 carbohydrates 1 carbohydrate 11 2 carbohydrates, 0 1 fats 1 carbohydrate 11 2 carbohydrates 1 carbohydrate 2 carbohydrates 1 carbohydrate, 1 fat 1 carbohydrate 1 carbohydrate 21 2 carbohydrates, 2 fats 1 carbohydrate 1 carbohydrate 4 carbohydrates 1 carbohydrate, 1 fat 1 carbohydrate, 0 1 fat 1 carbohydrate 3 carbohydrates, 0 1 fat united states: exchange lists g-7 table g-8 u.s. exchange system: nonstarchy vegetable list 1 vegetable exchange (cid:2) 5 g carbohydrate, 2 g protein, 0 g fat, and 25 kcal note: in general, one vegetable exchange is 1 2 c cooked vegetables or vegetable juice; 1 c raw vegetables. -starchy vegetables such as corn, peas, and potatoes are on the starch list (table g-4). -artichokes artichoke hearts asparagus beans (green, wax, italian) bean sprouts beets broccoli brussels sprouts cabbage carrots cauli ower celery cucumbers eggplant green onions or scallions greens (collard, kale, mustard, turnip) kohlrabi leeks mixed vegetables (without corn, peas, or pasta) (cid:2) 400 mg or more sodium per exchange. -mushrooms okra onions pea pods peppers (all varieties) radishes salad greens (endive, escarole, lettuce, romaine, spinach) sauerkraut spinach summer squash (crookneck) tomatoes tomatoes, canned tomato sauce tomato/vegetable juice turnips water chestnuts watercress zucchini g a p p e n d i x g-8 appendix g table g-9 u.s. exchange system: meat and meat substitutes list note: in general, a meat exchange is 1 oz meat, poultry, or cheese; 1 2 c dried beans (weigh meat and poultry and measure beans after cooking). -serving size food serving size food very lean meat and substitutes 1 very lean meat exchange (cid:2) 7 g protein, 0 1 g fat, 35 kcal 2 tbs 1 oz 11 2 oz 1 oz 1 oz grated parmesan cheeses with (cid:4)3 g fat/oz hot dogs with (cid:4)3 g fat/oz processed sandwich meat with (cid:4)3 g fat/oz (turkey pastrami or kielbasa) liver, heart (high in cholesterol) medium-fat meat and substitutes 1 medium-fat meat exchange (cid:2) 7 g protein, 5 g fat, and 75 kcal 1 oz 1 oz 1 oz 1 oz 1 oz 1 oz 1 oz 1 oz 1 4 c (2 oz) 1 1 oz 1 c 1 4 c 4 oz or 1 2 c beef: most beef products (ground beef, meatloaf, corned beef, short ribs, prime grades of meat trimmed of fat, such as prime rib) pork: top loin, chop, boston butt, cutlet lamb: rib roast, ground veal: cutlet (ground or cubed, unbreaded) poultry: chicken (dark meat, with skin), ground turkey or ground chicken, fried chicken (with skin) fish: any fried sh product cheese with (cid:4)5 g fat/oz: feta mozzarella ricotta egg (high in cholesterol, limit to 3/week) sausage with (cid:4)5 g fat/oz soy milk tempeh tofu high-fat meat and substitutes 1 high-fat meat exchange (cid:2) 7 g protein, 8 g fat, 100 kcal 1 oz 1 oz 1 oz 1 oz pork: spareribs, ground pork, pork sausage cheese: all regular cheeses (american dar, monterey jack, swiss) , ched- processed sandwich meats with 8 g fat/oz (bologna, pimento loaf, salami) sausage (bratwurst, italian, knockwurst, polish, smoked) 1 (10/lb) hot dog (turkey or chicken) 3 slices (20 slices/lb) bacon 1 tbs count as 1 high-fat meat (cid:5) 1 fat exchange: peanut butter (contains unsaturated fat) 1 (10/lb) hot dog (beef, pork, or combination) 1 oz 1 oz 1 oz 1 oz 1 4 c 1 oz 1 oz 2 1 4 c 1 oz 1 oz poultry: chicken or turkey (white meat, no skin), cornish hen (no skin) fish: fresh or frozen cod, ounder, haddock, halibut, trout, lox (smoked salmon) or canned in water ; tuna, fresh shell sh: clams, crab, lobster, scallops, shrimp, imitation shell sh game: duck or pheasant (no skin), venison, buf- falo, ostrich cheese with (cid:4)1g fat/oz: fat-free or low-fat cottage cheese fat-free cheese processed sandwich meats with (cid:4)1 g fat/oz (such as deli thin, shaved meats, chipped beef turkey ham) , egg whites egg substitutes, plain hot dogs with (cid:4)1 g fat/oz 1 oz count as 1 very lean meat (cid:5) 1 starch exchange: kidney (high in cholesterol) sausage with (cid:4)1 g fat/oz 1 2 c beans, peas, lentils (cooked) lean meat and substitutes 1 lean meat exchange (cid:2) 7 g protein, 3 g fat, 55 kcal 1 oz 1 oz 1 oz 1 oz 1 oz g x i d n e p p a 1 oz 6 medium 1 oz 2 medium 1 oz 1 oz 1 4 c beef: usda select or choice grades of lean beef trimmed of fat (round, sirloin, and ank steak); tenderloin; roast (rib, chuck, rump); steak (t-bone, porterhouse, cubed), ground round pork: lean pork (fresh ham); canned, cured, or boiled ham; canadian bacon center loin chop ; tenderloin, lamb: roast, chop, leg veal: lean chop, roast poultry: chicken, turkey (dark meat, no skin), chicken (white meat, with skin), domestic duck or goose (well drained of fat, no skin) fish: herring (uncreamed or smoked) oysters salmon (fresh or canned), cat sh sardines (canned) tuna (canned in oil, drained) game: goose (no skin), rabbit cheese: 4.5%-fat cottage cheese (cid:2) 400 mg or more of sodium per serving. -table g-10 u.s. exchange system: fat list 1 fat exchange (cid:2) 5 g fat and 45 kcal note: in general, one fat exchange is 1 tsp regular butter, margarine, or vegetable oil; 1 tbs regu- lar salad dressing. -many fat-free and reduced fat foods are on the free foods list (table g-11). -serving size food monounsaturated fats 2 tbs (1 oz) avocado 1 tsp 8 large 10 large 6 nuts 6 nuts 10 nuts 4 halves 1 2 tbs 1 tbs 2 tsp oil (canola, olive, peanut) olives, ripe (black) olives, green, stuffed almonds, cashews mixed nuts (50% peanuts) peanuts pecans peanut butter, smooth or crunchy sesame seeds tahini or sesame paste polyunsaturated fats 4 halves english walnuts 1 tsp 1 tbs 1 tsp 1 tbs 1 tsp 1 tbs 2 tbs 2 tsp 1 tbs 1 tbs saturated fats* 1 slice (20 slices/lb) 1 tsp 1 tsp 2 tsp 1 tbs 2 tbs (1 2 oz) 2 tbs 1 tbs 2 tbs 1 tbs (1 2 oz) 11 2 tbs (3 4 oz) 1 tsp 2 tbs 3 tbs margarine, stick, tub, or squeeze margarine, lower-fat spread (30% to 50% vegetable oil) mayonnaise, regular mayonnaise, reduced-fat oil (corn, saf ower, soybean) salad dressing, regular salad dressing, reduced-fat mayonnaise type salad dressing, regular mayonnaise type salad dressing, reduced-fat seeds (pumpkin, sun ower) bacon, cooked bacon, grease butter, stick butter, whipped butter, reduced-fat chitterlings, boiled coconut, sweetened, shredded coconut milk cream, half and half cream cheese, regular cream cheese, reduced-fat fatback or salt pork shortening or lard sour cream, regular sour cream, reduced-fat (cid:2) 400 mg or more sodium per exchange * saturated fats can raise blood cholesterol levels. -use a piece 1(cid:3) (cid:6) 1(cid:3) (cid:6) 1 4(cid:3) if you plan to eat the fatback cooked with vegetables. -use a piece 2(cid:3) (cid:6) 1(cid:3) (cid:6) 1 2(cid:3) when eating only the vegetables with the fatback removed. -united states: exchange lists g-9 g a p p e n d i x g-10 appendix g table g-11 u.s. exchange system: free foods list note: a serving of free food contains less than 20 kcalories or no more than 5 grams of carbohydrate; those with serving sizes should be limited to 3 serv- ings a day whereas those without serving sizes can be eaten freely. -serving size food fat-free or reduced-fat foods 1 tbs (1 2 oz) cream cheese, fat-free 1 tbs 2 tsp 4 tbs 1 tsp 1 tbs 1 tsp 1 tbs 1 tsp 1 tbs 2 tbs 1 tbs 1 tbs 2 tbs creamers, nondairy, liquid creamers, nondairy, powdered margarine spread, fat-free margarine spread, reduced-fat mayonnaise, fat-free mayonnaise, reduced-fat mayonnaise type salad dressing, fat-free mayonnaise type salad dressing, reduced-fat nonstick cooking spray salad dressing, fat-free or low-fat salad dressing, fat-free, italian sour cream, fat-free, reduced-fat whipped topping, regular whipped topping, light or fat-free sugar-free foods 1 piece candy, hard, sugar-free 2 tsp 2 tbs drinks gelatin dessert, sugar-free gelatin, un avored gum, sugar-free jam or jelly, light sugar substitutes syrup, sugar-free bouillon, broth, consomm bouillon or broth, low-sodium carbonated or mineral water club soda 1 tbs cocoa powder, unsweetened (cid:2) 400 mg or more of sodium per serving. -serving size food coffee condiments 1 tbs 1 tbs 11 2 medium 2 slices 3 4 oz 1 4 c 1 tbs 1 tbs 2 tbs seasonings diet soft drinks, sugar-free drink mixes, sugar-free tea tonic water, sugar-free catsup horseradish lemon juice lime juice mustard pickle relish pickles, dill pickles, sweet (bread and butter) pickles, sweet (gherkin) salsa soy sauce, regular or light taco sauce vinegar yogurt flavoring extracts garlic herbs, fresh or dried hot pepper sauces pimento spices wine, used in cooking worcestershire sauce g x i d n e p p a table g-12 u.s. exchange system: combination foods list united states: exchange lists g-11 food entr es tuna noodle casserole, lasagna, spaghetti with meatballs, chili with beans, macaroni and cheese chow mein (without noodles or rice) tuna or chicken salad frozen entr es and meals dinner-type meal entr e or meal with <340 kcal meatless burger, soy based meatless burger, vegetable and starch based pizza, cheese, thin crust pizza, meat topping, thin crust pot pie soups bean cream (made with water) instant instant with beans/lentils split pea (made with water) tomato (made with water) vegetable beef, chicken noodle, or other broth-type fast foods burrito with beef chicken nuggets chicken breast and wing, breaded and fried chicken sandwich, grilled chicken wings, hot fish sandwich/tartar sauce french fries hamburger, regular hamburger, large hot dog with bun individual pan pizza pizza, cheese, thin crust pizza, meat, thin crust soft serve cone submarine sandwich submarine sandwich ((cid:7)6 g fat) taco, hard or soft shell (cid:2) 400 mg or more sodium per exchange. -serving size exchanges per serving 1 c (8 oz) 2 carbohydrates, 2 medium-fat meats 2 c (16 oz) 1 2 c (31 2 oz) generally 14 17 oz about 8 11 oz 3 oz 3 oz 1 4 of 12(cid:3) (6 oz) 1 4 of 12(cid:3) (6 oz) 1 (7 oz) 1 c 1 c (8 oz) 6 oz prepared 8 oz prepared 1 2 c (4 oz) 1 c (8 oz) 1 c (8 oz) 1 (5 7 oz) 6 1 each 1 6 (5 oz) 1 1 carbohydrate, 2 lean meats 1 2 carbohydrate, 2 lean meats, 1 fat 3 carbohydrates, 3 medium-fat meats, 3 fats 2 3 carbohydrates, 1 2 lean meats 1 2 carbohydrate, 2 lean meats 1 carbohydrate, 1 lean meat 2 carbohydrates, 2 medium-fat meats, 1 fat 2 carbohydrates, 2 medium-fat meats, 2 fats 21 2 carbohydrates, 1 medium-fat meat, 3 fats 1 carbohydrate, 1 very lean meat 1 carbohydrate, 1 fat 1 carbohydrate 21 2 carbohydrates, 1 very lean meat 1 carbohydrate 1 carbohydrate 1 carbohydrate 3 carbohydrates, 1 medium-fat meat, 1 fat 1 carbohydrate, 2 medium-fat meats, 1 fat 1 carbohydrate, 4 medium-fat meats, 2 fats 2 carbohydrates, 3 very lean meats 1 carbohydrate, 3 medium-fat meats, 4 fats 3 carbohydrates, 1 medium-fat meat, 3 fats 1 medium serving (5 oz) 4 carbohydrates, 4 fats 1 1 1 1 1 4 of 12(cid:3) (about 6 oz) 1 4 of 12(cid:3) (about 6 oz) 1 small (5 oz) 1 sub (6(cid:3)) 1 sub (6(cid:3)) 1 (3 31 2 oz) 2 carbohydrates, 2 medium-fat meats 2 carbohydrates, 3 medium-fat meats, 1 fat 1 carbohydrate, 1 high-fat meat, 1 fat 5 carbohydrates, 3 medium-fat meats, 3 fats 21 2 carbohydrates, 2 medium-fat meats 21 2 carbohydrates, 2 medium-fat meats, 1 fat 21 2 carbohydrates, 1 fat 3 carbohydrates, 1 vegetable, 2 medium-fat meats, 1 fat 21 2 carbohydrates, 2 lean meats 1 carbohydrate, 1 medium-fat meat, 1 fat g a p p e n d i x appendix h contents table of food composition table of food composition this edition of the table of food composition includes a wide variety of foods. -it is up- dated with each edition to re ect current nutrient data for foods, to remove outdated foods, and to add foods that are new to the marketplace. -* the nutrient database for this appendix is compiled from a variety of sources, including the usda standard re- lease database and manufacturers data. -the usda database provides data for a wider variety of foods and nutrients than other sources. -because laboratory analysis for each nutrient can be quite costly, manufacturers tend to provide data only for those nutrients mandated on food labels. -consequently, data for their foods are often incomplete; any missing information on this table is designated as a dash. -keep in mind that a dash means only that the information is unknown and should not be in- terpreted as a zero. -a zero means that the nutrient is not present in the food. -whenever using nutrient data, remember that many factors in uence the nutrient contents of foods. -these factors include the mineral content of the soil, the diet fed to the animal or the fertilizer used on the plant, the season of harvest, the method of process- ing, the length and method of storage, the method of cooking, the method of analysis, and the moisture content of the sample analyzed. -with so many in uencing factors, users should view nutrient data as a close approximation of the actual amount. -for updates, corrections, and a list of more than 8000 foods and codes found in the diet analysis software that accompanies this text, visit www.thomsonedu.com/ nutrition and click on diet analysis plus. -fats total fats, as well as the breakdown of total fats to saturated, mono- unsaturated, polyunsaturated, and trans fats, are listed in the table. -the fatty acids seldom add up to the total in part due to rounding but also because val- ues are derived from a variety of laboratories. -trans fats trans fat data has been listed in the table. -because food manu- facturers have only been required to report trans fats on food labels since january 2006, much of the data is incomplete. -missing trans fat data is des- ignated with a dash. -as additional trans fat data becomes available, the table will be updated. -vitamin a and vitamin e in keeping with the 2001 rda for vitamin a, this appendix presents data for vitamin a in micrograms ( g) rae. -similarly, be- cause the 2000 rda for vitamin e is based only on the alpha-tocopherol form of vitamin e, this appendix reports vitamin e data in milligrams (mg) alpha-tocopherol, listed on the table as vit e (mg ). -bioavailability keep in mind that the availability of nutrients from foods de- pends not only on the quantity provided by a food, but also on the amount absorbed and used by the body the bioavailability. -the bioavailability of fo- late from forti ed foods, for example, is greater than from naturally occurring sources. -similarly, the body can make niacin from the amino acid tryptophan, but niacin values in this table (and most databases) report preformed niacin only. -chapter 10 provides conversion factors and additional details. -using the table the foods and beverages in this table are organized into several categories, which are listed at the head of each right-hand page. -page numbers are provided, and each group is color-coded to make it easier to nd individual foods. -caffeine sources caffeine occurs in several plants, including the familiar coffee bean, the tea leaf, and the cocoa bean from which chocolate is made. -*this food composition table has been prepared by wadsworth publishing company. -the nutritional data are supplied by axxya systems. -h x i d n e p p a most human societies use caffeine regularly, most often in beverages, for its stimulant effect and avor. -caffeine contents of beverages vary depending on the plants they are made from, the climates and soils where the plants are grown, the grind or cut size, the method and duration of brewing, and the amounts served. -the accompanying table shows that, in general, a cup of coffee contains the most caffeine; a cup of tea, less than half as much; and cocoa or chocolate, less still. -as for cola beverages, they are made from kola nuts, which contain caffeine, but most of their caffeine is added, using the puri ed compound obtained from decaffeinated coffee beans. -the fda lists caffeine as a multipurpose gras substance that may be added to foods and beverages. -drug manufacturers use caffeine in many products. -table caffeine content of selected beverages, foods, and medications table of food composition h-1 reminder: a gras substance is one that is generally recognized as safe. -beverages and foods serving size average (mg) beverages and foods serving size average (mg) coffee brewed decaffeinated instant tea brewed, green brewed, herbal brewed, leaf or bag instant lipton brisk iced tea nestea cool iced tea snapple iced tea (all avors) soft drinks a & w creme soda barq s root beer coca-cola 8 oz 8 oz 8 oz 8 oz 8 oz 8 oz 8 oz 12 oz 12 oz 16 oz 12 oz 12 oz 12 oz dr. pepper, mr. pibb, sunkist orange 12 oz a&w root beer, club soda, fresca, ginger ale, 7-up, sierra mist, sprite, squirt, tonic water, caffeine-free soft drinks mello yello mountain dew pepsi energy drinks amp aqua blast aqua java e maxx java water kmx krank red bull red devil sobe adrenaline rush sobe no fear water joe 12 oz 12 oz 12 oz 12 oz 8.4 oz .5 l .5 l 8.4 oz .5 l 8.4 oz .5 l 8.3 oz 8.4 oz 8.3 oz 16 oz .5 l 95 2 64 30 0 47 26 7 12 42 29 18 30 36 0 51 45 32 70 90 55 74 125 33 100 67 42 77 141 65 other beverages chocolate milk or hot cocoa starbucks frappuccino mocha starbucks frappuccino vanilla yoohoo chocolate drink candies baker s chocolate 8 oz 9.5 oz 9.5 oz 9 oz 1 oz dark chocolate covered coffee beans 1 oz dark chocolate, semisweet milk chocolate 1 oz 1 oz milk chocolate covered coffee beans 1 oz white chocolate 1 oz foods frozen yogurt, ben & jerry s coffee fudge frozen yogurt, h agen-dazs coffee ice cream, starbucks coffee ice cream, starbucks frappuccino bar 1 cup 1 cup 1 cup 1 bar yogurt, dannon coffee avored 1 cup 5 72 64 3 26 235 18 6 224 0 85 40 50 15 45 drugsa cold remedies serving size average (mg) coryban-d, dristan 1 tablet diuretics aqua-ban pre-mens forte pain relievers 1 tablet 1 tablet anacin, bc fast pain reliever 1 tablet excedrin, midol, midol max strength 1 tablet stimulants awake, nodoz 1 tablet awake maximum strength, caffedrine, nodoz maximum strength, stay awake, vivarin weight-control aids dexatrim 1 tablet 1 tablet 30 100 100 32 65 100 200 200 h a p p e n d i x aa pharmacologically active dose of caf ene is de ned as 200 milligrams. -note: the fda suggests a maximum of 65 milligrams per 12-ounce cola beverage but does not regulate the caffeine contents of other beverages. -because products change, contact the manufac- turer for an update on products you use regularly. -source: adapted from usda database release 18 (http://www.nal.usda.gov/fnic/foodcomp/data/), caffeine content of foods and drugs, center for science and the public interest (www.cspinet.org/new/cafchart.htm), and r. r. mccusker, b. a. goldberger, and e. j. cone, caffeine content of energy drinks, carbonated sodas, and other beverages, journal of analytical toxicology 30 (2006): 112 114. h-2 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 8534 4910 4911 8538 12079 25008 16729 25166 325 8716 25176 327 9079 8582 8585 329 8591 8597 332 1393 8604 8605 8608 8609 8613 1409 7905 338 334 8625 10168 8653 8654 336 8588 8592 491 8596 8670 8671 340 1395 386 8772 8737 4931 8756 393 8757 1397 411 8817 8819 8822 8791 25010 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans breads, baked goods, cakes, cookies, crackers, chips, pies bagels cinnamon & raisin enriched, all varieties plain, enriched, toasted oat bran whole grain biscuits biscuits scone wheat biscuits bread boston brown, canned bread sticks, plain cornbread cracked wheat croutons, plain egg egg, toasted french french, toasted indian fry italian mixed grain mixed grain, toasted oat bran oat bran, toasted oatmeal oatmeal, toasted pita pita, whole wheat pumpernickel raisin, enriched raisin, toasted rice, white rye rye, toasted rye, light sourdough sourdough, toasted submarine or hoagie roll vienna, toasted wheat wheat, toasted white whole wheat cakes angel food, from mix butter pound, ready to eat, commercially prepared carrot, cream cheese frosting, from mix chocolate, chocolate icing, commercially prepared chocolate, from mix devil s food cupcake, chocolate frosting fruitcake, ready to eat, commercially prepared pineapple upside down, from mix sponge, from mix white, coconut frosting, from mix yellow, chocolate frosting, ready to eat, commercially prepared yellow, vanilla frosting, ready to eat, commercially prepared snack cakes chocolate snack cake, creme lled, w/frosting cinnamon coffee cake 1 1 1 1 1 1 1 1 1 4 1 1 1 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) slice(s) item(s) piece(s) slice(s) cup(s) slice(s) slice(s) slice(s) slice(s) item(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) item(s) item(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) item(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) item(s) piece(s) slice(s) slice(s) slice(s) slice(s) slice(s) item(s) piece(s) 71 71 66 71 85 41 42 55 45 24 55 25 8 40 37 25 23 90 30 26 24 30 27 27 25 60 64 32 26 24 42 32 29 25 25 23 135 23 25 23 25 46 50 75 111 64 95 35 43 115 63 112 64 64 50 72 23 23 18 23 16 11 21 21 1 26 9 <1 14 10 9 7 24 11 10 8 13 10 10 8 19 20 12 9 7 12 9 9 9 7 41 7 9 7 9 15 16 18 23 15 23 8 11 37 19 23 14 14 10 23 195 195 195 181 170 121 149 162 88 99 141 65 31 115 117 69 69 296 81 65 65 71 70 73 73 165 170 80 71 71 140 83 82 65 69 69 400 69 65 65 67 128 129 291 484 235 340 120 139 367 187 399 243 239 188 231 7 7 7 8 9 3 4 4 2 3 5 2 1 4 4 2 2 6 3 3 3 3 3 2 2 5 6 3 2 2 1 3 3 2 2 2 11 2 2 2 2 4 3 4 5 3 5 2 1 4 5 5 2 2 2 4 39 38 38 38 35 16 19 22 19 16 18 12 6 19 19 13 13 48 15 12 12 12 12 13 13 33 35 15 14 14 21 15 15 12 13 13 72 13 12 12 13 24 29 37 52 35 51 20 26 58 36 71 35 38 30 36 2 2 2 3 6 1 1 1 2 1 1 1 <1 1 1 1 1 2 1 2 2 1 1 1 1 1 5 2 1 1 1 2 2 2 1 1 4 1 1 1 1 3 <1 <1 1 2 2 1 2 1 <1 1 1 <1 <1 1 1 1 1 1 2.5 5 6 7 1 2 5 1 <1 2 2 1 1 9 1 1 1 1 1 1 1 1 2 1 1 1 6 1 1 1 1 1 8 1 1 1 1 2 <1 15 29 10 14 4 4 14 3 12 11 9 7 8 0.19 0.16 0.16 0.14 0 1.40 2.01 1.90 0.13 0.34 2.09 0.23 0.11 0.64 0.60 0.16 0.16 2.08 0.26 0.21 0.21 0.21 0.21 0.19 0.19 0.10 0.26 0.14 0.28 0.28 0.50 0.20 0.20 0.20 0.16 0.16 1.80 0.16 0.22 0.22 0.18 0.37 0.12 0.09 0.09 0.18 1.41 2.55 1.92 0.09 0.86 1.44 0.48 0.23 0.92 1.11 0.30 0.30 3.59 0.24 0.40 0.40 0.48 0.47 0.43 0.43 0.06 0.22 0.30 0.60 0.60 0.42 0.42 0.30 0.30 0.30 3.00 0.30 0.43 0.43 0.17 0.53 0.48 0.49 0.49 0.35 1.82 1.26 2.51 0.25 0.87 1.50 0.17 0.10 0.44 0.43 0.17 0.17 2.33 0.42 0.24 0.24 0.51 0.50 0.46 0.46 0.32 0.68 0.40 0.18 0.18 0.26 0.25 0.30 0.17 0.17 2.20 0.17 0.23 0.23 0.34 1.35 0.02 0.01 0.06 0 0 0 0 0 0 0 0.80 15.10 8.67 5.43 3.05 5.16 1.80 0.45 3.35 0.82 4.36 4.43 7.24 5.61 5.74 1.60 1.81 5.97 0.99 4.14 1.18 2.62 0.60 1.43 3.77 0.41 2.42 2.98 6.14 1.35 1.52 3.91 3.30 1.43 2.19 2.85 2.65 2.62 2.99 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-3 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 <1 49 <1 <1 0 21 0 0 20 21 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 166 60 27 55 19 2 25 107 1 35 35 9 26 13 53 53 9 200 33 80 57 32 5 88 11 6 37 38 19 19 210 23 24 24 20 19 18 18 52 10 22 17 17 40 23 23 20 19 19 100 19 26 26 38 15 42 26 28 28 57 21 14 138 26 101 24 40 37 50 2.70 2.53 2.52 2.19 1.08 1.01 1.31 1.22 0.95 1.03 1.01 0.70 0.31 1.22 1.24 0.63 0.63 3.24 0.88 0.90 0.90 0.94 0.93 0.73 0.74 1.57 1.96 0.92 0.75 0.76 1.08 0.91 0.90 0.70 0.63 0.63 3.80 0.63 0.83 0.83 0.94 1.43 0.12 1.04 1.39 1.41 1.53 0.70 0.89 1.70 1.00 1.30 1.33 0.68 1.68 1.46 20 21 20 22 120 6 7 16 28 8 10 13 2 8 8 7 7 14 8 14 14 11 9 10 10 16 44 17 7 7 13 12 4 7 7 7 12 12 6 37 4 8 20 22 30 7 15 6 13 19 4 21 10 105 72 72 82 0 37 48 81 143 30 59 44 9 46 47 28 28 67 33 53 53 44 33 38 39 72 109 67 59 59 45 53 53 51 28 28 128 28 50 50 25 144 68 89 124 128 133 46 66 129 89 111 229 379 379 360 200 205 288 321 284 158 209 135 52 197 200 152 152 626 175 127 127 122 121 162 163 322 340 215 101 102 160 211 210 175 152 152 683 152 133 132 170 159 255 299 273 214 299 92 116 367 144 318 0.80 0.62 0.62 0.64 4.5 0.27 0.29 0.42 0.23 0.21 0.57 0.31 0.07 0.32 0.32 0.22 0.22 0.45 0.26 0.33 0.33 0.27 0.28 0.28 0.28 0.50 0.97 0.47 0.19 0.19 0.36 0.36 0.18 0.22 0.22 0.22 0.26 0.26 0.19 0.69 0.07 0.35 0.54 0.44 0.66 0.12 0.36 0.37 0.37 114 216 0.40 34 220 0.16 61 81 213 277 0.26 0.38 15 0 0 1 0 9 12 11 0 38 0 0 25 26 0 0 0 0 0 0 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 112 38 3 71 49 13 21 12 3 35 0.27 0.38 0.31 0.24 0.44 0.13 0.15 0.16 0.01 0.14 0.13 0.09 0.05 0.18 0.14 0.13 0.10 0.39 0.14 0.11 0.08 0.15 0.12 0.11 0.09 0.36 0.22 0.10 0.09 0.07 0.23 0.14 0.11 0.10 0.13 0.10 0.54 0.10 0.10 0.08 0.11 0.14 0.22 0.07 0.08 0.23 0.01 0.43 0.01 0.14 0.24 0.33 0.10 0.11 0.08 0.07 0.09 0.09 0.08 0.13 0.13 0.13 0.13 0.18 0.39 0.13 0.07 0.07 0.11 0.11 0.08 0.07 0.07 0.07 0.07 0.05 0.35 0.20 0.22 0.20 0.24 0.5 0.12 0.16 0.13 0.05 0.13 0.16 0.06 0.02 0.17 0.16 0.08 0.07 0.27 0.09 0.09 0.08 0.10 0.09 0.06 0.06 0.20 0.05 0.10 0.10 0.09 0.14 0.11 0.10 0.08 0.08 0.07 0.33 0.07 0.07 0.06 0.08 0.10 2.19 3.24 2.91 2.10 8 1.08 1.20 1.49 0.50 1.27 0.98 0.92 0.41 1.94 1.77 1.19 1.07 3.27 1.31 1.13 1.02 1.45 1.29 0.85 0.77 2.78 1.82 0.99 0.90 0.81 1.20 1.22 1.09 0.80 1.19 1.07 4.50 1.07 1.03 0.93 1.10 1.83 0.04 0.04 0.03 0.03 0.6 0.01 0.03 0.03 0.04 0.02 0.04 0.08 0.00 0.03 0.02 0.01 0.01 0.02 0.01 0.09 0.08 0.02 0.01 0.02 0.02 0.02 0.17 0.04 0.02 0.02 0.02 0.02 0.01 0.01 0.01 0.05 0.01 0.02 0.02 0.02 0.09 0.05 0.00 0.10 0.09 0.00 0.10 0.15 0.02 0.13 0.04 0.02 0.18 0.10 0.14 0.08 0.06 0.39 0.13 0.98 0.17 0.09 0.20 0.05 0.04 0.18 0.19 0.21 0.03 1.13 0.37 1.08 0.30 0.34 1.37 0.76 1.19 31 0.08 0.03 0.04 0.02 0.04 0.04 0.03 0.10 0.80 0.02 0.04 0.32 0.02 0.11 0.14 1.09 0.23 0.15 0.16 1.21 1.17 0.01 0.02 79 75 64 70 26 8 29 5 39 36 15 10 42 36 37 22 67 57 31 28 24 19 17 13 64 22 30 28 24 40 35 30 5 37 22 22 23 19 28 30 10 0 13 11 26 2 9 30 25 35 14 17 20 30 <1 0 0 <1 0 0 <.1 <.1 0 0 2 0 0 0 0 0 0 0 0 <.1 <.1 0 0 0 <.1 0 0 0 <.1 <.1 0 <1 <.1 0 0 0 0 0 0 0 0 0 0 <1 1 <.1 <1 0 <1 1 0 <1 0 0 0 <.1 0 0 0 0 1.79 <.1 <1 <.1 <.1 0 <1 <.1 0 <.1 <.1 0 0 0 0 <.1 <.1 0 0 <.1 <.1 0 0 0 0 0 0 0 <.1 0 0 0 0 0 0 0 <.1 7 <1 <.1 <1 <.1 <.1 <1 <.1 <1 <.1 <.1 <1 22 23 23 24 0 7 12 10 9 6 6 3 12 12 8 8 21 8 8 8 9 9 7 7 16 28 8 5 5 10 10 8 8 8 42 8 8 8 4 18 8 2 11 2 1 11 12 12 2 4 1 10 h a p p e n d i x h-4 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 16777 8794 29428 29429 38192 654 8816 4641 5096 4632 8859 8876 25207 8915 14145 8920 25208 25213 33095 9002 9008 9010 9012 8928 9016 9024 14189 9014 9028 9040 432 9046 9048 9050 9052 9054 9044 9055 9057 9059 9061 9022 16754 5118 4945 9096 4947 9105 9115 437 9117 10617 30928 25015 4997 9189 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans breads, baked goods, cakes, cookies, crackers, chips, pies continued 37 9 funnel cake sponge snack cake, creme lled item(s) item(s) 90 43 1 1 snacks, chips, pretzels bagel chips, plain bagel chips, toasted onion chex traditional snack mix potato chips, salted potato chips, unsalted tortilla chips, plain pretzels, plain, hard, twists pretzels, whole wheat cookies animal crackers brownie, prepared from mix chocolate chip cookies chocolate sandwich cookie, extra creme lling fig newtons fortune cookie oatmeal cookies peanut butter cookies sugar cookies vanilla sandwich cookie, creme lling crackers cheese crackers (mini) cheese crackers (mini), low salt cheese cracker sandwich w/peanut butter honey graham crackers matzo crackers, plain melba toast ritz crackers rye crispbread crackers rye melba toast rye wafer saltine crackers saltine crackers, low salt snack crackers, round snack crackers, round, low salt snack cracker sandwich, cheese lling snack cracker sandwich, peanut butter lling soda crackers wheat crackers wheat crackers, low salt wheat cracker sandwich, cheese lling wheat cracker sandwich, peanut butter lling whole wheat crackers pastry apple fritter cinnamon sweet roll w/icing, from refrigerator dough croissant, butter danish pastry, nut doughnut, cake doughnut, cake, chocolate glazed doughnut, creme lling doughnut, glazed doughnut, jelly lling toaster pastry, brown sugar cinnamon toaster pastry, cream cheese muf ns blueberry bran, from mix corn, ready to eat 3 3 1 20 20 6 5 1 12 1 1 1 1 1 1 1 1 1 30 30 4 4 1 3 5 1 3 1 5 5 10 10 4 4 5 10 10 4 4 7 1 1 1 1 1 1 1 1 1 1 1 1 1 1 item(s) item(s) cup(s) item(s) item(s) item(s) item(s) ounce(s) piece(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 29 29 46 28 28 28 30 28 30 24 30 13 16 8 69 35 16 10 30 30 28 28 28 15 16 10 15 11 15 15 30 30 28 28 15 30 30 28 28 28 17 30 57 65 47 42 85 60 85 50 54 63 50 57 1 1 1 1 1 0 3 4 <1 1 12 4 4 <1 1 1 1 1 1 1 <1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 6 7 13 13 10 7 32 15 30 5 30 18 19 278 155 130 130 198 152 152 142 114 103 134 112 140 65 55 30 234 163 61 48 151 151 139 118 112 59 80 37 58 37 65 65 151 151 134 138 65 142 142 139 139 124 62 109 231 280 198 175 307 242 289 210 200 160 138 174 7 1 3 4 3 2 2 2 3 3 2 1 2 <1 1 <1 6 4 1 <1 3 3 3 2 3 2 1 1 2 1 1 1 2 2 3 3 1 3 3 3 4 2 1 2 5 5 2 2 5 4 5 3 3 3 3 3 29 27 19 20 33 15 15 18 24 23 22 12 16 9 10 7 45 17 7 7 17 17 16 22 24 11 10 8 12 9 11 11 18 18 17 16 11 19 19 16 15 19 6 17 26 30 23 24 26 27 33 35 23 23 23 29 1 <1 1 1 2 1 1 2 1 2 <1 1 1 <1 1 <1 3 1 <1 <1 1 1 1 1 1 1 1 2 1 3 <1 <1 <1 <1 1 1 <1 1 1 1 1 3 <1 1 1 1 1 1 1 1 1 1 1 1 2 2 14 5 5 5 6 10 10 7 1 1 4 7 8 3 1 <1 4 9 3 2 8 8 7 3 <1 <1 4 <1 1 <.1 2 2 8 8 6 7 2 6 6 7 7 5 4 4 12 16 11 8 21 14 16 6 11 6 5 5 2.77 1.09 0.50 0.50 0.76 3.11 3.11 1.43 0.23 0.16 1.03 1.76 2.09 0.50 0.50 0.05 0.70 1.65 0.63 0.30 2.81 2.82 1.23 0.43 0.06 0.07 0.50 0.01 0.07 0.01 0.44 0.44 1.13 1.13 1.72 1.38 0.44 1.55 1.55 1.16 1.29 0.95 4.46 1.73 2.79 2.79 4.39 0.41 0.29 2.29 2.60 3.26 1.39 0.50 0.11 1.28 4.72 1.27 0.84 3.63 2.70 3.64 1.14 0.04 0.12 1.50 0.02 0.14 0.02 0.96 0.96 3.19 3.19 3.15 3.86 0.96 3.43 3.43 2.90 3.29 1.65 6.33 1.40 3.46 3.46 1.03 0.37 0.24 0.56 2.26 2.09 1.22 0.00 0.04 1.85 2.43 0.87 0.76 0.74 1.44 1.43 1.07 0.17 0.19 0.00 0.06 0.20 0.04 0.25 0.25 2.86 2.86 0.72 1.30 0.25 0.84 0.84 2.57 2.48 1.85 0.87 1.69 1.13 1.00 6.59 3.78 1.70 2.16 4.62 3.49 4.12 1.00 3.50 0.87 1.18 0.77 2.23 3.15 8.90 4.37 4.74 10.27 7.72 8.69 4.00 1.48 2.34 1.20 0.52 0.62 2.78 3.70 1.04 2.62 1.74 2.02 1.00 3.25 0.72 1.83 0 1.10 0.50 0 0 0 0.54 0.54 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-5 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 63 7 128 19 0 0 0 0 0 0 0 0 0 18 13 0 0 <1 <.1 13 18 0 4 4 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 2 0 0 14 0 38 30 17 24 20 4 22 0 15 20 34 15 0 0 0 7 7 44 11 8 13 14 11 3 5 1 26 28 5 3 45 45 14 7 4 14 20 3 12 4 18 18 36 36 72 23 18 15 15 57 48 14 9 10 21 61 21 89 21 26 21 0 0 50 16 42 1.86 0.55 0.72 0.72 0.55 0.46 0.46 0.43 1.30 0.76 0.82 0.44 0.70 0.37 0.36 0.12 1.94 0.67 0.32 0.22 1.43 1.44 0.76 1.04 0.90 0.56 0.72 0.24 0.55 0.65 0.81 0.81 1.08 1.08 0.67 0.78 0.81 1.32 1.32 0.73 0.75 0.86 0.25 0.80 1.16 1.17 0.92 0.95 1.56 0.36 1.50 1.80 1.08 1.15 1.27 1.60 18 3 0 19 19 25 11 9 5 13 12 4 1 49 22 2 1 11 11 16 8 7 9 3 8 6 13 4 4 8 8 10 15 4 19 19 15 11 28 2 4 9 21 9 14 17 13 17 7 29 18 154 37 45 50 76 362 362 56 44 122 30 42 62 16 40 3 177 104 13 9 44 32 61 38 32 30 10 32 29 54 19 109 40 107 120 60 19 55 61 86 83 83 24 19 67 62 60 45 68 65 67 70 56 74 39 273 155 70 300 623 169 2 150 515 58 1118 82 109 64 60 22 311 157 50 35 299 137 199 169 1 124 135 26 135 87 195 95 254 112 392 201 195 239 85 256 226 185 0.64 0.12 0.00 0.31 0.31 0.43 0.26 0.18 0.19 0.23 0.24 0.08 0.01 1.43 0.46 0.08 0.04 0.34 0.33 0.29 0.23 0.19 0.30 0.23 0.24 0.20 0.31 0.12 0.12 0.20 0.20 0.17 0.32 0.12 0.48 0.48 0.24 0.23 0.60 2 0 0 0 0 0 1 0 0 42 27 0 4 <.1 48 51 31 0 9 0 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 5 0 0 0.24 0.07 0.09 0.05 0.05 0.02 0.14 0.12 0.10 0.03 0.07 0.01 0.03 0.01 0.23 0.08 0.04 0.03 0.17 0.18 0.15 0.06 0.11 0.06 0.07 0.02 0.07 0.05 0.08 0.08 0.12 0.12 0.12 0.14 0.08 0.15 0.15 0.10 0.11 0.06 1.55 0.50 1.91 2.59 1 0.04 0.54 0.25 0.00 0.23 0.74 0.28 0.16 0.66 0.16 0.09 0.02 0.06 0.08 0.09 0.15 0.02 0.61 0.61 0.06 0.58 0.15 0.15 0.15 0.24 0.32 0.06 0.05 0.06 0.06 0.05 0.19 0.08 0.09 0.05 0.06 0.02 0.04 0.01 0.12 0.09 0.04 0.02 0.13 0.12 0.08 0.09 0.08 0.04 0.04 0.01 0.04 0.03 0.07 0.07 0.10 0.10 0.19 0.08 0.07 0.10 0.10 0.12 0.08 0.03 1.86 0.52 1.22 1.09 1.09 0.36 1.58 1.86 1.04 0.24 0.82 0.20 0.22 0.15 1.24 1.81 0.28 0.27 1.40 1.41 1.63 1.15 1.11 0.62 0.45 0.10 0.71 0.17 0.79 0.79 1.21 1.21 1.05 1.71 0.79 1.49 1.49 0.89 1.65 1.27 0.05 0.01 0.00 0.19 0.19 0.08 0.03 0.08 0.00 0.02 0.02 0.00 0.00 0.09 0.05 0.01 0.00 0.17 0.18 0.04 0.02 0.03 0.01 0.01 0.02 0.01 0.03 0.01 0.01 0.02 0.02 0.01 0.04 0.01 0.04 0.04 0.07 0.04 0.05 7 0.09 0.03 0.07 0.04 0.23 0.01 250 424 236 257 143 263 205 249 190 230 288 234 297 0.10 0.43 0.57 0.26 0.24 0.68 0.46 0.64 0.39 0.57 0.31 101 6 5 9 2 14 20 30 0.12 0.22 0.14 0.10 0.02 0.29 0.53 0.27 0.15 0.14 0.10 0.16 0.53 0.09 0.25 0.37 0.76 0.46 0.07 0.14 0.16 0.11 0.03 0.13 0.04 0.12 0.17 0.15 0.12 0.19 1.09 1.25 1.50 0.87 0.20 1.91 0.39 1.82 2.00 1.14 1.44 1.16 0.01 0.03 0.07 0.03 0.01 0.06 0.03 0.09 0.20 0.03 0.09 0.05 14 17 12 13 13 3 51 15 50 7 16 6 5 30 21 8 5 46 8 26 13 5 19 10 5 13 5 19 19 27 27 28 24 19 35 15 18 20 8 2 14 35 54 22 19 60 13 58 40 29 33 46 <1 <.1 0 0 0 9 9 0 0 <1 0 <.1 <.1 0 <1 0 <1 <.1 <.1 0 0 0 0 0 0 0 1 0 0 <.1 0 0 0 0 <.1 0 0 0 0 <1 0 0 <1 <.1 <1 1 <.1 <.1 0 <.1 0 0 0 <1 0 0 <1 <.1 0 0 0 0 0 0 0 <.1 <.1 <.1 <.1 <.1 <.1 <.1 <.1 0 <1 <1 <.1 0 0 0 0 0 0 0 0 0 0 0 <.1 <.1 0 0 0 <.1 0 0 <.1 <.1 <.1 <1 <1 <.1 <1 <.1 <1 0 <1 <.1 <.1 1 2 2 2 2 3 4 <1 <1 17 5 3 <1 3 2 3 10 5 4 6 3 2 3 2 2 6 3 2 2 10 7 6 4 13 9 0 2 9 5 11 9 9 h a p p e n d i x h-6 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans da + code 9121 29582 9145 38161 38196 38187 1383 4606 454 470 472 9007 5052 8555 489 490 5127 5130 37026 37024 36580 36583 36584 12005 16078 16080 16079 1391 1669 1390 8926 5037 9219 500 30311 2861 1953 1956 1957 1963 1967 1969 1972 129 2863 37488 30280 28066 2867 482 484 486 1194 h x i d n e p p a breads, baked goods, cakes, cookies, crackers, chips, pies continued 24 19 24 english muf n, plain, enriched english, toasted english, wheat item(s) item(s) item(s) 57 50 57 1 1 1 granola bars kudos milk chocolate w/fruit & nuts nature valley banana nut crunchy nature valley fruit n nut trail mix plain, hard plain, soft pies apple pie, from home recipe pecan pie, from home recipe pumpkin pie, from home recipe pie crust, frozen, ready to bake, enriched, baked pie crust, prepared w/water, baked rolls crescent dinner roll hamburger roll or bun, plain hard roll kaiser roll whole wheat roll or bun sport bars balance original chocolate balance original peanut butter clif bar chocolate brownie energy bar clif bar crunchy peanut butter energy bar clif luna tropical crisp energy bar powerbar apple cinnamon powerbar banana powerbar chocolate powerbar mocha tortillas corn tortillas, soft flour tortilla taco shells, hard pancakes, waf es pancakes, blueberry, from recipe pancakes, from mix w/egg & milk waf e, plain, frozen, toasted waf e, plain, from recipe waf e, 100% whole grain 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 3 2 1 1 cereal, flour, grain, pasta, noodles, popcorn grain amaranth, dry barley, pearled, cooked buckwheat groats, cooked, roasted bulgur, cooked couscous, cooked millet, cooked oat bran, dry quinoa, dry rice brown, long grain, cooked brown, medium grain, cooked jasmine, saffroned, cooked pilaf, cooked spanish, cooked white glutinous, cooked white, instant long grain, enriched, boiled white, long grain, boiled white, long grain, enriched, parboiled, cooked wild brown, cooked 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 item(s) item(s) item(s) item(s) item(s) slice(s) slice(s) slice(s) slice(s) slice(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) 134 128 127 90 95 140 115 126 411 503 316 82 100 80 120 167 167 76 200 200 240 240 180 230 230 230 230 58 104 62 253 249 174 218 201 365 97 77 76 88 143 116 318 4 4 5 2 2 3 2 2 4 6 7 1 1 2 4 6 6 2 14 14 10 12 10 10 9 10 10 1 3 1 7 9 4 6 7 14 2 3 3 3 4 8 11 26 25 26 15 14 25 16 19 58 64 41 8 10 14 21 30 30 15 22 22 41 39 24 45 45 45 45 12 18 8 33 33 27 25 25 65 22 17 17 18 28 31 59 22 108 3 109.19 2.26 22.92 8 2 2 2 340 129 25 84 78 22 1 18 28 21 35 25 28 155 122 155 16 20 28 43 57 57 28 50 50 68 68 48 65 65 65 65 26 32 13 114 114 66 75 75 98 79 84 91 79 120 47 85 1 2 73 24 91 2 2 10 15 18 18 9 11 9 1 61 60 28 <.1 32 10 54 64 71 57 86 3 8 71 98 97.5 0.07 280 74 103 3 120 67 87 83 79 88 82 63 54 81 103 63 0.06 100 82.81 2 2 2 18 22 22 3.27 17.49 2 1 3 1 1 2 1 1 2 0 0 <1 <1 1 1 1 1 2 1 1 6 5 2 3 3 3 3 1 1 1 1 2 2 2 2 15 3 2 4 1 2 7 5 2 1.75 0 1 <1 1 <1 <1 <1 1.47 1 1 1 3 4 4 5 5 19 27 14 5 6 1 2 2 2 1 6 6 4 5 5 3 2 2 3 1 2 3 10 9 5 11 8 6 <1 1 <1 <1 1 3 5 1 0.8 0 3 <1 <1 <1 <1 <1 0.27 0.15 0.14 0.16 1.00 0.50 0.50 0.58 2.06 4.73 4.87 4.92 1.69 1.54 0.34 0.47 0.35 0.35 0.24 3.50 2.50 1.00 0.50 3.50 0.50 0.50 0.50 1.00 0.09 0.56 0.43 2.26 2.33 0.95 2.14 2.35 1.62 0.07 0.11 0.04 0.02 0.21 0.62 0.50 0.18 0.16 0.00 0.67 0.33 0.03 0.04 0.06 0.06 0.04 0.17 0.16 0.16 1.07 1.08 8.36 13.64 5.73 2.51 3.46 0.70 0.48 0.65 0.65 0.34 0.00 1.50 1.00 0.50 1.00 0.17 1.21 1.19 2.64 2.36 2.12 2.64 3.38 1.40 0.04 0.16 0.03 0.02 0.22 1.12 1.30 0.32 0.29 1.61 0.07 0.06 0.04 0.07 0.07 0.04 0.51 0.48 0.48 2.95 1.51 5.17 6.97 2.81 0.65 0.77 0.25 0.85 0.98 0.98 0.62 0.00 0.50 0.50 1.00 0.50 0.29 0.34 1.13 4.74 3.33 1.84 5.08 2.06 2.82 0.17 0.16 0.09 0.05 0.61 1.30 1.99 0.31 0.28 0.95 18.31 0.06 0.04 0.06 0.06 0.17 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-7 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 17 4 5 12 15 11 <1 8 22 22 14 18 18 18 14 25 1 7 2 16 11 35 0 0 0 0 0 0 0 <1 0 106 65 0 0 0 0 0 0 0 3 3 0 0 0 0 0 0 0 0 0 0 64 81 16 52 71 149 9 6 9 6 4 27 51 10 9.75 13 47 2 7 8 17 2.46 30 95 101 200 10 0 15 30 11 39 146 3 12 39 59 54 54 30 100 100 250 250 350 300 300 300 300 46 40 21 235 245 153 191 196 7.40 1.04 0.67 0.87 0.30 0.76 2.54 7.86 0.41 0.51 2.16 1.16 0.78 0.12 0.52 0.95 0.99 0.49 1.43 1.36 1.64 0.36 0.54 0.00 0.72 0.73 1.74 1.81 1.97 0.36 0.43 0.89 1.43 1.87 1.87 0.69 4.50 4.50 5.40 5.40 6.30 6.30 6.30 6.30 6.30 0.36 1.06 0.33 1.96 1.48 2.95 1.73 1.56 259 17 43 29 6 53 110 179 42 42.9 9 48 4 4 9 12 11 21 24 21 11 32 29 3 3 6 9 15 15 24 40 40 120 120 140 140 140 140 140 17 8 14 18 25 15 14 30 357 73 74 62 46 74 266 629 42 77.02 55 1 9 3 28 75 72 106 60 82 92 122 162 288 18 12 39 40 62 62 78 160 130 260 300 120 110 200 150 150 40 42 24 157 227 84 119 173 20 2 3 5 4 2 2 18 5 0.97 780 403 13 4 2 1 11 26.23 32 82.81 3 2.46 264 252 218 60 80 95 72 79 327 320 349 104 146 157 206 310 310 136 180 230 150 290 135 90 90 90 90 42 153 49 470 576 519 383 374 3.10 0.64 0.51 0.52 0.20 1.09 1.46 2.81 0.61 0.6 0.38 0.13 0.36 0.20 0.39 0.27 1.09 0.40 0.38 0.61 0.50 0.43 0.29 1.24 0.71 0.05 0.08 0.17 0.28 0.54 0.54 0.57 3.75 3.75 3.75 3.75 5.25 5.25 5.25 5.25 5.25 0.24 0.23 0.19 0.62 0.86 0.38 0.50 0.85 0 0 0 0 0 0 0 0 0 0 <1 0 0 0 0 0 0 0 0 0 0 0 2 0 17 100 660 0 0 0 0 0 0 0 0 0 0 0 0 0 0 57 82 253 49 0.08 0.07 0.03 0.05 0.05 0.13 0.55 0.17 0.09 0.09 0.13 0.03 0.02 0.06 0.13 0.22 0.04 0.25 0.19 0.25 0.06 0.08 0.23 0.23 0.14 0.04 0.06 0.14 0.17 0.27 0.27 0.07 0.38 0.38 0.38 0.38 1.50 1.50 1.50 1.50 1.50 0.03 0.17 0.03 0.22 0.23 0.25 0.19 0.15 0.01 0.08 0.01 0.10 0.02 0.47 0.03 0.28 0.06 0.03 0.01 0.03 0.01 0.17 0.26 0.42 0.02 0.03 0.24 0.07 0.06 0.22 0.65 0.32 0.20 0.05 0.03 0.03 0.02 0.10 0.10 0.34 0.02 0.01 0.02 0.19 0.01 0.04 0.01 0.02 0.07 0.16 0.14 0.17 0.03 0.05 0.17 0.22 0.31 0.06 0.04 0.09 0.14 0.19 0.19 0.04 0.43 0.43 0.26 0.34 1.70 1.70 1.70 1.70 1.70 0.02 0.09 0.01 0.31 0.36 0.31 0.26 0.25 1.25 1.62 0.79 0.91 0.77 1.60 0.44 2.49 1.49 1.29 1.24 8.71 0.25 0.73 1.17 1.23 1.05 2.21 1.90 1.91 0.39 0.15 1.91 1.03 1.21 0.39 0.47 1.10 1.79 2.42 2.42 1.05 5.00 5.00 4.00 6.00 20.00 20.00 20.00 20.00 20.00 0.39 1.14 0.18 1.74 1.40 2.93 1.55 1.47 0.22 0.09 0.06 0.08 0.04 0.13 0.08 0.19 0.14 0.14 0.06 0.14 0.02 0.01 0.07 0.02 0.11 0.02 0.02 0.05 0.02 0.03 0.05 0.07 0.07 0.01 0.01 0.01 0.03 0.02 0.02 0.06 0.50 0.50 0.40 0.40 2.00 2.00 2.00 2.00 2.00 0.06 0.02 0.04 0.06 0.12 0.59 0.04 0.09 48 13 12 16 12 23 24 42 4 3.9 4 <.1 1 58 46 67 21.31 42 15 36 6 7 37 32 33 9 20 48 54 54 9 100 100 80 100 400 400 400 400 400 26 33 17 41 105 36 51 14 4 0 0 0 0 0 0 0 0 0 <1 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 <.1 0 0 0 0 <1 0 3 <1 3 0 0 0 0 0 0 0 60 60 60 60 60 60 60 60 60 0 0 0 3 1 0 <1 <1 0 0 0 0 0 0 0 0 0 0 <.1 <.1 0 0 0 0 0 <.1 <.1 0 0 0 <1 0 <1 <1 <.1 0 <.1 <.1 0 0 0 2 2 1 1 6 6 6 6 6 0 0 0 <1 <1 2 <1 <1 7 2 1 22 1 21 10 38 9 5 3 6 7 0.65 h a p p e n d i x h-8 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 505 503 1643 383 504 426 424 1644 1976 1645 1978 1980 2827 1990 506 39230 10574 10647 10648 10649 363 8636 1260 365 8657 5500 5510 1197 1200 1199 13633 1204 1205 1206 3415 1207 5522 1211 1247 1937 1220 38214 372 38215 10268 38216 1223 13334 13335 2415 1227 2424 10286 1231 30569 1233 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans cereal, flour, grain, pasta, noodles, popcorn continued flour & grain fractions all purpose our, self rising, enriched all purpose our, white, bleached, enriched barley our buckwheat our, whole groat cake wheat our, enriched cornmeal, degermed, enriched cornmeal, yellow whole grain masa corn our, enriched rice our, brown rice our, white rye our, dark semolina, enriched soy our, raw wheat germ, crude whole wheat our breakfast bars atkins morning start apple crisp health valley fat free apple nutri-grain blueberry cereal bar nutri-grain raspberry cereal bar nutri-grain strawberry cereal bar breakfast cereals, hot corn grits, white, regular & quick, enriched, cooked w/water & salt corn grits, yellow, regular & quick, enriched, cooked w/salt cream of wheat, instant, prepared farina, enriched, cooked w/water & salt oatmeal, cooked w/water oatmeal, maple & brown sugar, instant, prepared oatmeal, ready to serve, packet breakfast cereals, ready to eat all-bran all-bran buds apple jacks bran flakes, post cap n crunch cap n crunch crunchberries w/wildberry colors cheerios cocoa puffs cocoa rice krispies complete wheat bran akes corn flakes corn pops cracklin oat bran froot loops frosted cheerios frosted flakes frosted mini chex frosted mini-wheats frosted wheaties granola, prepared granola, quaker 100% natural, oats & honey granola, quaker 100% natural, oats, honey & raisins honey bunches of oats honey roasted honey nut cheerios honeycomb kashi puffed kix life lucky charms 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 2 1 2 1 1 1 1 1 1 2 1 2 1 2 1 2 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5 1 1 2 1 2 1 2 1 1 1 1 1 1 1 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) cup(s) item(s) item(s) item(s) item(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) 63 63 56 60 55 69 61 57 79 79 64 84 43 14 60 37 38 37 37 37 7 7 6 7 7 8 6 5 9 9 7 11 2 2 6 5 5 5 121 103 121 121 117 117 198 186 103 106 102 100 150 158 62 91 33 40 36 35 30 30 41 39 28 31 65 32 30 41 40 51 40 61 48 51 40 30 22 25 23 43 30 2 3 1 1 1 1 1 1 1 1 1 1 0 1 1 3 0 0 0 1 1 <1 <1 2 1 221 228 198 201 197 253 221 208 287 289 207 301 186 52 203 170 110 140 140 140 71 71 61 56 74 200 112 160 212 130 133 144 139 110 120 160 120 100 120 266 120 120 160 146 180 146 299 219 225 160 120 83 70 90 160 120 6 6 4 8 4 6 5 5 6 5 9 11 15 3 8 11 2 2 2 2 2 2 2 2 3 5 4 8 6 1 4 2 2 3 1 1 4 2 1 5 1 2 1 1 5 1 9 5 5 3 3 2 3 2 4 2 46 48 45 42 43 54 47 43 60 63 44 61 15 7 44 12 26 27 27 27 16 16 13 12 13 40 20 46 73 30 32 30 29 22 26 36 31 24 28 47 28 25 37 36 41 36 32 31 34 33 24 20 13 20 33 25 2 2 2 6 1 5 4 5 4 2 14 3 4 2 7 6 3 1 1 1 <1 <1 <1 <1 2 2 3 20 42 1 7 1 1 3 0 1 7 1 0 7 1 1 1 0 5 <1 5 3 3 1 2 <1 2 1 3 1 1 1 1 2 <1 1 2 2 2 1 2 1 9 1 1 9 0 3 3 3 <1 <1 <.1 <.1 1 2 2 2 3 1 1 2 2 2 1 1 1 0 0 9 1 1 0 0 1 0 15 9 9 2 2 <1 1 <1 2 1 0.10 0.05 0.26 0.10 0.16 0.41 0.07 0.16 0.31 0.30 0.44 0.30 0.20 0.13 1.27 0.24 0.19 4.00 0.00 0.50 0.50 0.50 0.05 0.10 0.57 0.04 0.28 0.58 0.57 0.80 0.35 0.21 0.10 1.94 0.20 0.14 0.00 2.00 2.00 2.00 0.26 0.38 0.57 0.21 0.49 1.00 0.98 0.79 0.30 0.77 0.36 4.96 0.86 0.47 0.00 0.50 0.50 0.50 0.03 0.06 0.10 0.03 0.01 0.01 0.19 0.42 0.38 0.00 0.00 0.53 0.49 0.00 0.67 0.00 0.00 2.70 0.50 0.00 0.00 0.00 0.00 0.00 2.76 0.06 0.01 0.01 0.37 0.74 0.66 0.00 0.00 0.39 0.39 0.50 0.00 0.00 0.00 4.70 0.00 0.00 0.00 0.00 0.00 0.00 4.7 0.10 0.04 0.03 0.44 0.85 0.76 1.00 0.71 0.27 0.28 0.50 0.00 0.00 0.00 1.33 0.00 0.00 0.00 0.00 0.50 0.00 6.53 3.83 4.0 1.19 3.57 0.67 0.00 0.00 0.00 0.00 0.35 0.00 3.80 1.20 0.50 0.00 0.64 0.00 1.10 0.13 0.00 0.00 0.61 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-9 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <.1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 211 2.92 9 16 25 8 3 4 80 9 8 36 14 88 6 20 200 0 200 200 200 4 4 27 5 9 26 21 300 0 0 0 5 7 100 100 53 0 0 0 27 0 100 0 133 0 133 48 2.90 0.71 2.44 3.99 2.85 2.10 4.11 1.56 0.28 4.13 3.64 2.71 0.90 2.33 0.72 1.80 1.80 1.80 0.73 0.73 8.60 0.58 0.80 6.84 3.96 9.00 13.64 4.50 10.77 6.00 6.14 8.10 4.50 5.99 23.94 8.10 1.80 2.38 4.50 4.50 5.99 11.97 15.30 10.77 2.59 61 1.21 59 0 100 0 0 113 124 100 1.24 3.59 4.50 2.03 0.72 6.08 11.92 4.50 12 14 45 151 9 28 77 63 88 28 159 39 183 34 83 8 8 8 6 6 2 2 28 50 45 200 182 8 80 20 19 40 8 11 53 3 2 80 8 16 4 60 0 107 51 49 21 24 6 6 41 16 78 794 0.39 67 186 346 57 112 175 170 228 60 467 155 1070 128 243 90 160 75 70 55 25 25 17 15 66 126 112 700 909 35 253 72 71 95 50 67 226 25 25 293 35 55 27 33 170 47 328 225 250 67 95 26 35 26 121 60 1 4 7 1 2 21 3 6 0 1 1 6 2 3 70 25 110 110 110 270 270 1 383 1 404 241 160 606 150 293 269 242 280 170 253 279 200 120 186 150 210 200 266 5 266 13 20 19 253 270 165 0 203 218 210 0.44 1.05 1.87 0.34 0.50 1.11 1.01 1.94 0.63 3.60 0.88 1.67 1.77 1.76 1.50 1.50 1.50 0.08 0.08 0.10 0.09 0.57 1.04 0.93 3.00 4.55 1.50 2.00 4.99 5.12 3.75 3.75 2.00 19.95 0.17 1.50 2.00 1.50 3.75 0.21 3.99 1.50 9.98 2.5 1.04 0.99 0.40 3.75 1.13 2.81 5.32 3.75 0 0 0 0 0 8 7 0 0 0 1 0 3 0 0 0 2 0 0 0 0 0 300 455 150 3 2 150 0 200 299 150 150 299 150 200 0 2 1 <1 0 113 1 0.42 0.03 0.26 3.65 0.03 123 0.49 0.07 0.25 0.49 0.49 0.23 0.81 0.35 0.11 0.20 0.68 0.25 0.27 0.27 0.23 0.09 0.38 0.38 0.38 0.04 0.19 0.01 0.10 0.26 0.09 0.95 0.09 0.90 0.22 0.93 0.49 0.31 0.03 0.11 0.23 0.28 0.12 0.43 0.06 0.02 0.16 0.48 0.49 0.07 0.13 0.26 0.03 0.43 0.43 0.43 3.69 2.57 3.69 3.70 3.47 2.22 5.61 5.01 2.05 2.73 5.00 1.84 0.98 3.82 3.00 0.40 5.00 5.00 5.00 0.03 0.16 0.35 0.02 0.18 0.19 0.21 0.58 0.34 0.28 0.09 0.20 0.19 0.20 0.50 0.50 0.50 114 13 32 101 161 15 133 13 3 38 153 147 40 26 40 40 40 0.10 0.02 0.07 0.87 0.03 40 0.10 0.07 0.07 0.13 1.02 0.60 0.75 1.14 0.38 0.50 0.51 0.51 0.38 0.38 0.50 2.00 0.38 0.38 0.49 0.38 0.38 0.50 0.50 0.38 1.00 0.44 0.12 0.12 0.50 0.38 0.28 0.03 0.28 0.53 0.38 0.02 0.01 0.12 3.59 0.07 0.04 0.05 0.02 0.05 0.05 0.85 1.29 0.43 0.57 0.57 0.57 0.43 0.43 0.57 2.26 0.43 0.43 0.56 0.43 0.43 0.57 0.57 0.43 1.13 0.17 0.87 0.60 0.57 0.15 1.57 0.78 10.00 15.15 5.00 6.65 6.66 6.66 5.00 5.00 6.65 26.60 5.00 5.00 6.65 5.00 5.00 6.65 6.65 5.00 13.30 1.29 0.03 0.01 0.01 0.02 0.31 0.19 4.00 6.06 0.50 0.67 0.67 0.67 0.50 0.50 0.67 2.66 0.50 0.50 0.67 0.50 0.50 0.67 0.67 0.50 1.33 0.18 40 357 40 5 30 19 800 1212 100 133 133 133 200 100 133 532 100 100 218 100 100 133 266 100 532 51 0.11 0.81 0.07 17 0.11 0.57 0.43 0.32 0.03 0.32 0.60 0.43 0.8 6.65 5.00 3.74 0.80 3.75 7.10 5.00 0.07 0.67 0.50 0.37 0.00 0.38 0.70 0.50 16 133 200 75 150 142 200 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 9 1 0 0 0 0 0 0 0 0 0 0 12 18 15 0 0 <.1 6 6 20 80 6 6 20 15 6 8 8 0 8 1 <1 <1 0 6 0 0 5 0 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 12 18 2 2 0 0 2 2 2 8 2 2 2 2 2 2 2 2 4 0 0.1 0.1 2 2 1 1 0 2 22 21 2 3 3 5 9 9 12 23 75 3 11 42 4 3 11 9 11 4 6 26 2 7 7 11 2 6 4 1 2 14 2 2 2 16.95 8.3 8.82 7 5 11 6 h a p p e n d i x h-10 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 1201 38220 1238 1241 32432 32433 2420 1244 1245 5593 1248 1246 3428 1253 1254 382 1257 449 1995 448 440 1996 1725 2878 2879 493 2884 1563 2000 476 4619 4620 477 223 224 946 948 952 225 226 227 38492 228 230 229 233 234 2998 235 4580 237 958 238 959 960 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans cereal, flour, grain, pasta, noodles, popcorn continued multi-bran chex multi grain cheerios nutri-grain golden wheat product 19 puffed rice, forti ed puffed wheat, forti ed raisin bran rice chex rice krispies shredded wheat smacks special k total, corn akes total whole grain trix wheat germ, toasted wheaties pasta, noodles chinese chow mein noodles, cooked corn pasta, cooked egg noodles, enriched, cooked macaroni, enriched, cooked pasta, plain, fresh-refrigerated, cooked ramen noodles, cooked soba noodles, cooked somen noodles, cooked spaghetti, al dente, cooked spaghetti, whole wheat, cooked spinach egg noodles, enriched, cooked tricolor vegetable macaroni, enriched, cooked popcorn air popped caramel cheese avored popped in oil fruit and fruit juices apples raw medium, w/peel slices slices w/o skin, boiled dried, sulfured juice, from frozen concentrate juice, unsweetened, canned applesauce, sweetened, canned applesauce, unsweetened, canned crabapples apricot fresh w/o pits halves, dried, sulfured halves w/skin, canned in heavy syrup avocado california, whole, w/o skin or pit florida, whole, w/o skin or pit pureed banana fresh whole, w/o peel dried chips blackberries raw unsweetened, frozen blueberries raw canned in heavy syrup unsweetened, frozen 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 1 1 1 1 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 4 1 4 1 2 1 1 1 8 1 1 4 1 2 1 2 1 2 1 2 1 2 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) item(s) cup(s) cup(s) item(s) item(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) 58 30 40 30 14 12 59 25 26 25 36 31 23 40 30 14 30 23 70 80 70 64 114 95 88 65 70 80 67 8 35 37 33 138 55 85 22 120 124 128 122 35 140 33 129 170 304 29 118 55 72 76 72 128 78 1 1 <1 0 5 1 1 1 1 1 1 1 1 0 1 <1 48 55 46 44 95 69 60 42 47 55 46 <1 1 1 1 118 47 73 7 105 109 101 108 28 121 10 100 <1 <1 21 88 2 63 62 61 98 67 200 110 133 100 56 43.68 190 96 96 88 133 110 83 146 120 53.95 110 4 3 4 2 1 1.76 4 2 2 3 3 7 2 3 1 4.11 3 49 24 31 25 13 9.55 47 22 23 20 32 22 18 31 27 7 24 7 3 5 1 <1 0.52 8 <1 0 3 1 1 1 4 1 2.13 3 119 88 106 99 84 104 94 115 95 87 105 86 31 152 196 165 72 29 45 52 56 58 97 52 27 67 79 107 284 365 46 105 287 31 48 41 113 40 2 2 4 3 3 3 5 4 4 4 4 3 1 1 3 3 <1 <1 <1 <1 <1 <.1 <1 <1 <1 2 1 1 3 7 1 1 1 1 1 1 1 1 13 20 20 20 16 15 20 24 20 19 19 18 6 28 19 19 19 8 12 14 14 14 25 14 7 16 21 28 15 24 2 27 32 7 12 10 28 10 1 3 1 1 0 1 0 0 1 3 2 3 1 2 4 3 3 1 2 2 <1 <1 2 1 1 3 2 2 12 17 2 3 4 4 4 2 2 2 2 1 1 0 <.1 0.14 1 0 0 1 1 0 0 1 1 1.51 1 7 1 1 <1 1 4 <.1 <1 1 <1 1 <.1 <1 5 12 9 <1 <.1 <1 <.1 <1 <1 <1 <.1 <1 1 <1 <1 26 31 4 <1 19 <1 <1 <1 <1 1 0.00 0.00 0.00 0.00 0.02 0.02 0.00 0.00 0.00 0.04 0.00 0.00 0.00 0.00 0.00 0.25 0.00 0.99 0.07 0.25 0.07 0.10 0.19 0.02 0.02 0.05 0.07 0.29 0.00 0.00 0.00 0.00 0.10 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.21 0.00 1.73 0.13 0.34 0.06 0.08 0.22 0.02 0.02 0.05 0.05 0.39 0.00 0.00 0.67 0.00 0.36 0.00 0.00 0.10 0.00 0.00 0.00 0.00 0.00 0.93 0.00 3.90 0.23 0.33 0.19 0.27 0.21 0.03 0.06 0.15 0.15 0.28 0.01 0.01 0.03 0.05 1.27 2.38 1.61 0.04 0.02 0.05 0.01 0.02 0.02 0.04 0.01 0.02 0.04 0.01 0.01 3.59 5.90 0.61 0.13 16.00 0.01 0.01 0.02 0.03 0.04 0.09 1.01 3.61 2.70 0.01 0.00 0.01 0.00 0.00 0.01 0.01 0.00 0.00 0.24 0.02 0.04 16.61 16.70 2.82 0.04 1.08 0.03 0.03 0.03 0.06 0.07 0.15 1.58 5.72 4.43 0.07 0.03 0.09 0.02 0.04 0.04 0.07 0.02 0.03 0.11 0.02 0.02 3.42 5.00 0.52 0.09 0.35 0.20 0.18 0.11 0.18 0.22 0 0 0 0 0 0 0.02 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-11 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 26 0 21 18 0 0 0 0 26 0 0 2 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 100 100 0 0 1 3.35 20 80 0 10 0 0 750 1330 100 6.35 0 5 1 10 5 4 9 4 7 7 11 15 7 1 15 42 3 8 3 4 3 7 9 5 4 6 18 18 12 22 30 3 6 10 21 22 4 6 6 16.20 18.00 1.46 18.00 4.44 3.8 10.80 7.20 1.44 1.08 0.48 8.70 13.50 23.94 4.50 1.28 8.10 1.06 0.18 1.27 0.98 0.73 0.89 0.45 0.46 1.00 0.74 0.87 0.33 0.22 0.61 0.83 0.92 0.17 0.07 0.16 0.30 0.31 0.46 0.45 0.15 0.13 0.55 0.88 0.39 1.00 0.50 0.16 0.31 0.69 0.45 0.60 0.20 0.42 0.14 60 24 32 16 4 17.39 80 7 13 31 11 16 0 32 0 45.2 32 220 85 146 50 16 41.75 340 28 32 92 53 60 23 120 15 133.76 110 12 25 15 13 12 9 9 2 12 21 19 13 11 12 34 36 7 3 3 3 6 4 4 4 2 14 11 9 49 73 8 32 42 14 17 4 5 4 27 22 22 22 15 34 33 25 52 31 30 21 24 38 97 74 148 59 75 97 151 148 78 92 68 363 383 181 861 1067 139 422 296 117 106 55 51 42 390 200 279 210 <1 0.47 300 232 256 2 67 220 158 253 190 0.56 220 99 0 6 1 4 415 57 141 1 2 10 4 <1 73 331 292 1 1 1 19 8 4 4 2 <1 1 3 5 14 6 2 1 3 1 1 1 4 1 3.75 15.00 4.99 15.00 0.14 0.28 2.25 3.00 0.48 0.70 0.40 0.90 11.25 19.95 3.75 2.35 7.50 0.32 0.44 0.49 0.37 0.36 0.31 0.11 0.19 0.35 0.57 0.50 0.29 0.28 0.20 0.75 0.87 0.06 0.02 0.03 0.04 0.05 0.04 0.05 0.04 0.28 0.13 0.14 1.12 1.20 0.18 0.18 0.41 0.38 0.19 0.12 0.09 0.06 158 0 225 0 0 120 0 200 225 113 200 150 0 150 0 2 5 0 4 0 0 0 0 4 3 1 1 14 3 4 2 2 0 0 0 1 1 0 134 59 80 104 185 2 4 2 8 5 2 3 2 0.38 1.50 0.50 1.50 0.36 0.31 0.53 0.30 0.30 0.07 0.50 0.53 1.13 2.00 0.38 0.23 0.75 0.13 0.04 0.15 0.14 0.13 0.08 0.09 0.02 0.12 0.08 0.20 22.50 31.24 2.26 0.78 0.14 0.04 0.04 0.21 0.46 0.03 1.70 0.57 1.70 0.25 0.21 0.60 0.34 0.34 0.06 0.57 0.60 1.28 2.26 0.43 0.11 0.85 0.09 0.02 0.07 0.07 0.10 0.05 0.02 0.03 0.07 0.03 0.10 5.00 20.00 6.65 20.00 4.94 4.23 7.00 4.00 4.80 1.77 6.65 7.00 15.00 26.60 5.00 0.78 10.00 1.34 0.39 1.19 1.17 0.63 0.71 0.48 0.09 0.90 0.49 1.18 0.50 2.00 0.67 2.00 0.01 0.02 0.70 0.40 0.40 0.10 0.67 2.00 1.50 2.66 0.50 0.13 1.00 0.02 0.04 0.03 0.02 0.02 0.03 0.04 0.01 0.04 0.06 0.09 0.08 0.06 0.04 0.72 0.02 0.02 0.02 0.05 0.04 0.02 0.01 0.01 0.00 0.00 0.03 0.02 0.02 0.01 0.04 0.00 0.03 0.12 0.00 0.02 0.04 0.05 0.01 0.02 0.03 0.04 0.03 0.02 0.42 0.04 0.11 0.01 0.01 0.27 0.26 1.25 1.43 0.77 3.35 0.09 0.60 0.12 0.13 0.84 0.88 0.41 0.49 0.37 0.02 0.02 0.09 0.04 0.04 0.01 0.01 0.03 0.02 0.02 0.04 0.03 0.01 0.06 0.02 0.03 0.24 0.10 0.04 0.09 0.01 0.02 0.03 0.03 0.07 0.03 0.16 0.77 0.54 0.51 0.13 0.05 0.08 0.20 0.05 0.12 0.24 0.23 0.04 0.84 0.85 0.49 3.24 2.00 0.50 0.78 0.39 0.47 0.91 0.30 0.14 0.41 0.02 0.01 0.09 0.07 0.06 0.02 0.04 0.03 0.04 0.04 0.03 0.03 0.08 0.05 0.07 0.47 0.20 0.07 0.43 0.14 0.02 0.05 0.04 0.05 0.05 100 400 133 400 3 3.83 140 160 80 12 133 400 300 532 100 49.72 200 20 4 51 54 41 4 7 2 8 4 51 44 2 2 4 6 4 2 1 0 0 0 1 1 2 13 3 3 105 106 17 24 8 18 26 4 3 6 6 15 20 60 0 0 0 5 5 0 8 15 45 80 6 0.84 6 0 0 0 0 0 <.1 0 0 0 0 0 0 0 0 <1 <.1 6 3 <1 1 1 1 2 1 3 14 <1 4 15 53 3 10 3 15 2 7 1 2 2 6 2 6 0 0 2 1 1 0 2 6 5 8 2 0 3 0 0 <.1 0 <.1 <.1 0 0 0 0 <1 0 0 <.1 <1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 9 4 1 14.77 1 4 1 17 7 1 2 6 9.18 1 10 2 17 15 40 18 17 13 1 1 4 2 0 0 <1 <1 <1 <1 <1 <1 <1 1 <1 1 0 <1 1 1 <1 <1 <.1 <1 0 h a p p e n d i x h-12 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 961 962 35576 3000 967 240 3004 969 3007 1638 241 1717 242 244 243 973 975 974 245 978 977 979 981 982 3022 247 251 249 248 983 255 256 259 3159 3060 987 35593 3027 8458 992 262 993 994 269 995 1038 1039 999 1005 271 1000 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fruit and fruit juices continued boysenberries canned in heavy syrup unsweetened, frozen breadfruit cherries sour red, raw sour red, canned in water sweet, raw sweet, canned in heavy syrup sweet, canned in water cranberries chopped, raw cranberry juice cocktail cranberry juice cocktail, low calorie, w/saccharin cranberry apple juice drink cranberry sauce, sweetened, canned dates domestic, chopped domestic, whole figs raw, medium canned in heavy syrup canned in water fruit cocktail & salad fruit cocktail, canned in heavy syrup fruit cocktail, canned in juice fruit cocktail, canned in water fruit salad, canned in water gooseberries raw canned in light syrup grapefruit raw, pink or red raw, white juice, pink, sweetened, canned juice, white sections, canned in light syrup sections, canned in water grapes american, slip skin european, red or green, adherent skin juice, sweetened, added vitamin c, from frozen concentrate juice drink, canned raisins, seeded, packed guava, raw guava, strawberry jackfruit kiwi fruit lemon raw juice peel lime raw juice loganberries, frozen mandarin orange canned in juice canned in light syrup mango nectarine, raw, sliced melons cantaloupe casaba melon 1 2 1 2 1 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 4 1 4 1 4 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 4 1 1 1 2 1 1 1 1 1 1 1 2 1 2 1 2 1 2 1 2 1 2 1 2 cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) item(s) cup(s) item(s) item(s) tablespoon(s) teaspoon(s) item(s) tablespoon(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) 128 66 384 78 122 73 127 124 55 127 127 123 69 98 57 271 67 110 60 98 108 48 108 120 100 42 44.5 44.5 0 0 101 130 124 124 119 119 123 75 126 115 118 125 124 127 122 46 80 125 125 41 90 6 83 77 108 15 2 67 15 74 125 126 104 69 80 85 80 99 106 100 104 108 112 66 101 <.1 107 109 111 106 <.1 37 <.1 109 109 7 77 5 61 63 94 14 2 61 14 62 111 105 85 60 72 78 113 33 396 39 44 46 105 57 25 72 24 87 105 126 126 74 114 66 91 55 38 37 33 92 48 39 58 48 76 44 31 55 64 63 122 46 4 78 53 22 4 1 15 4 40 46 77 67 30 27 24 1 1 4 1 1 1 1 1 <1 0 <.1 <.1 <1 1 1 1 <1 <1 <1 1 <1 <1 1 1 1 1 1 1 1 1 <1 1 <1 <1 1 1 <.1 1 1 1 <.1 <.1 <1 <.1 1 1 1 1 1 1 1 29 8 104 9 11 12 27 15 7 18 6 22 27 33 33 19 30 17 23 14 10 10 8 24 12 10 14 11 20 11 8 14 16 16 32 11 1 20 11 12 1 <1 6 1 10 12 20 18 7 7 6 3 3 17 1 1 2 2 2 3 <1 0 <1 1 4 4 3 3 3 1 1 1 1 3 3 2 1 <1 <1 1 <1 <1 1 <1 0 3 5 <1 1 3 5 <.1 <1 2 <.1 4 1 1 2 1 1 1 <1 <1 1 <1 <1 <1 <1 <1 <.1 <1 <.1 <.1 <1 <1 <1 <1 <1 <1 <.1 <.1 <.1 <.1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 0 <1 1 <.1 <1 1 <1 0 <.1 <.1 <.1 <1 <.1 <1 <1 <1 <1 <.1 0.01 0.01 0.00 0.05 0.03 0.03 0.04 0.03 0.01 0.01 0.00 0.00 0.01 0.01 0.01 0.06 0.03 0.02 0.01 0.00 0.01 0.01 0.03 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.05 0.04 0.04 0.00 0.07 0.15 0.01 0.05 0.02 0.04 0.00 0.00 0.01 0.00 0.01 0.00 0.02 0.07 0.02 0.04 0.02 0.02 0.02 0.00 0.06 0.03 0.03 0.05 0.04 0.01 0.02 0.00 0.00 0.01 0.01 0.01 0.07 0.03 0.03 0.02 0.00 0.01 0.02 0.04 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.01 0.01 0.01 0.00 0.01 0.05 0.00 0.04 0.03 0.01 0.00 0.00 0.01 0.00 0.02 0.01 0.02 0.10 0.06 0.00 0.00 0.09 0.10 0.00 0.07 0.04 0.04 0.06 0.05 0.03 0.06 0.00 0.00 0.05 0 0 0.14 0.06 0.06 0.04 0.00 0.02 0.03 0.24 0.14 0.04 0.03 0.03 0.03 0.03 0.03 0.05 0.04 0.03 0.00 0.07 0.23 0.02 0.07 0.19 0.10 0.00 0.00 0.02 0.00 0.13 0.01 0.03 0.05 0.08 0.07 0.03 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-13 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 23 18 65 12 13 9 11 14 4 4 11 6 3 17 17 35 35 35 7 9 6 9 19 20 25 14 10 11 18 18 6 8 5 4 12 18 1 28 30 66 1 3 9 1 19 14 9 10 4 7 9 0.55 0.56 2.07 0.25 1.67 0.26 0.44 0.45 0.14 0.19 0.05 0.15 0.15 0.45 0.45 0.37 0.36 0.36 0.36 0.25 0.30 0.37 0.23 0.42 0.09 0.07 0.45 0.25 0.51 0.50 0.13 0.29 0.13 0.13 1.07 0.28 0.01 0.50 0.38 0.76 0.00 0.02 0.06 0.00 0.47 0.34 0.47 0.13 0.19 0.17 0.29 14 11 96 7 7 8 11 11 3 3 3 2 2 19 19 17 13 12 6 8 8 6 8 8 10 11 13 15 13 12 2 6 5 4 12 9 1 31 14 13 1 <1 5 1 15 14 10 9 6 10 9 115 92 1882 134 120 161 183 162 47 23 32 34 18 292 292 233 128 128 109 113 111 96 149 97 155 175 203 200 164 161 88 153 26 41 340 256 18 251 251 157 19 3 78 17 107 166 98 161 139 215 155 4 1 8 2 9 0 4 1 1 3 4 9 20 1 1 1 1 1 7 5 5 4 1 3 0 0 3 1 3 2 1 2 3 1 12 3 2 2 2 3 <1 <1 1 <1 1 6 8 2 0 13 8 0.24 0.15 0.46 0.08 0.09 0.05 0.13 0.10 0.06 0.09 0.03 0.22 0.03 0.12 0.12 0.15 0.14 0.15 0.10 0.11 0.11 0.10 0.09 0.14 0.08 0.08 0.08 0.06 0.10 0.11 0.02 0.06 0.05 0.03 0.07 0.21 0.35 0.10 0.11 0.01 0.01 0.05 0.01 0.25 0.63 0.30 0.04 0.12 0.14 0.06 3 2 8 50 46 2 10 10 2 0 0 0 1 1 1 7 3 2 12 18 15 27 11 9 30 2 0 2 0 0 2 6 0 0 0 28 12 4 2 <1 <.1 1 <1 1 54 53 39 12 136 0 0.03 0.03 0.42 0.02 0.02 0.02 0.03 0.03 0.01 0.01 0.00 0.01 0.01 0.02 0.02 0.06 0.03 0.03 0.02 0.01 0.02 0.02 0.03 0.03 0.05 0.04 0.05 0.05 0.05 0.05 0.04 0.06 0.02 0.01 0.05 0.05 0.00 0.02 0.05 0.00 0.00 0.02 0.00 0.04 0.10 0.07 0.06 0.02 0.03 0.01 0.57 0.05 0.28 0.05 0.29 0.29 0.66 0.28 0.06 0.15 0.57 0.02 0.02 0.11 0.16 0.10 0.50 0.47 0.47 0.28 0.15 0.15 0.05 0.27 0.11 0.11 0.09 0.15 0.00 0.00 0.66 0.02 0.00 0.15 0.03 0.64 0.12 0.13 1.16 0.53 0.04 0.04 0.04 0.02 0.12 0.03 0.05 0.02 0.05 0.05 0.01 0.01 0.00 0.02 0.01 0.02 0.02 0.05 0.05 0.05 0.02 0.02 0.01 0.03 0.02 0.07 0.03 0.02 0.03 0.02 0.03 0.03 0.03 0.06 0.03 0.02 0.08 0.05 0.00 0.09 0.02 0.04 0.00 0.00 0.01 0.00 0.02 0.04 0.06 0.06 0.02 0.02 0.03 0.29 0.51 3.46 0.31 0.22 0.11 0.50 0.51 0.06 0.04 0.01 0.07 0.07 0.56 0.56 0.40 0.55 0.55 0.46 0.48 0.43 0.46 0.23 0.19 0.23 0.32 0.40 0.25 0.31 0.30 0.14 0.15 0.16 0.09 0.46 1.08 0.04 0.33 0.25 0.22 0.02 0.01 0.10 0.02 0.62 0.55 0.56 0.60 0.78 0.59 0.20 0.05 0.04 0.00 0.03 0.05 0.04 0.04 0.04 0.03 0.02 0.00 0.03 0.01 0.07 0.07 0.11 0.09 0.09 0.06 0.06 0.06 0.04 0.06 0.02 0.06 0.05 0.03 0.05 0.03 0.02 0.05 0.07 0.05 0.02 0.08 0.13 0.00 0.09 0.05 0.12 0.01 0.00 0.03 0.01 0.05 0.05 0.05 0.14 0.02 0.06 0.14 44 42 54 6 10 3 5 5 1 0 0 0 1 9 9 6 3 2 4 4 4 4 5 4 15 12 13 12 11 11 2 2 1 1 1 13 12 <.1 2 <1 7 1 19 6 6 14 3 17 7 8 2 111 8 3 5 5 3 7 45 41 39 1 <1 <1 2 1 1 2 3 2 2 21 13 36 39 34 47 27 27 2 9 30 20 2 165 2 6 74 83 7 3 20 5 11 43 25 29 4 30 19 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 <1 2 0 0 0 0 0 <.1 0 0 0 <1 1 1 <1 <1 <1 1 1 1 1 <1 1 <1 2 <1 <1 1 1 <.1 <.1 <1 <1 <1 1 <1 1 <.1 <.1 <.1 <.1 <1 <1 1 1 0 <1 <1 h a p p e n d i x h-14 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 272 318 273 3040 274 275 29630 14414 278 282 16830 35640 283 285 286 290 291 8672 293 294 1012 1017 295 3053 1019 296 1018 299 1024 300 1027 5644 305 306 309 310 311 313 315 16828 316 1040 1042 1043 8683 1044 2885 566 568 565 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fruit and fruit juices continued honeydew watermelon orange raw peel sections juice juice, fresh squeezed juice w/calcium & extra vitamin c juice, unsweetened, from frozen concentrate papaya raw dried, strips passion fruit, purple peach raw, medium halves, canned in heavy syrup halves, canned in water slices, sweetened, frozen pear raw asian danjou halves, canned in heavy syrup halves, canned in juice persimmon pineapple raw, diced canned in extra heavy syrup canned in juice canned in light syrup canned in water juice, unsweetened, canned plantain, cooked plum, raw, large pomegranate prunes dried dried, stewed juice, canned raisins, see grapes raspberries raw red, sweetened, frozen rhubarb, cooked with sugar strawberries raw sweetened, frozen, thawed tangelo tangerine raw juice vegetables, legumes amaranth leaves, raw leaves, boiled, drained arugula leaves, raw artichoke boiled, drained hearts, boiled, drained asparagus boiled, drained canned, drained tips, frozen, boiled, drained 1 2 1 2 1 1 1 2 1 2 1 2 1 2 1 2 1 2 2 1 1 1 2 1 2 1 2 1 1 1 1 2 1 2 1 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 1 2 1 2 1 1 2 1 2 1 2 1 2 1 2 1 1 1 2 1 1 2 1 1 1 2 1 2 1 2 1 2 cup(s) cup(s) item(s) teaspoon(s) cup(s) cup(s) cup(s) cup(s) 89 77 131 2 90 124 124 125 80 71 114 1 78 109 109 109 cup(s) 125 110 cup(s) item(s) item(s) item(s) cup(s) cup(s) cup(s) item(s) item(s) item(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) item(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) item(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) 70 46 18 98 131 122 125 166 122 200 133 124 25 78 130 125 126 123 125 77 83 154 17 119 256 62 125 120 72 128 95 84 124 28 66 20 120 84 90 121 90 62 12 13 87 104 114 93 139 108 168 107 107 16 67 101 104 108 112 107 52 72 125 5 <.1 208 53 91 82 65 100 82 74 110 26 60 18 101 71 0.08 114 82 32 23 62 2 43 56 56 55 56 27 119 17 38 97 29 118 96 51 120 98 62 32 37 108 75 66 39 70 89 38 105 40 128 182 32 129 140 23 99 45 37 53 6 14 5 60 42 20 23 25 <1 <1 1 <.1 1 1 1 1 1 <1 2 <1 1 1 1 1 1 1 1 <1 <1 <1 <1 <1 1 <1 1 <1 1 1 1 <1 1 2 1 1 1 <1 1 1 1 1 1 1 1 4 3 2 3 3 8 6 15 1 11 13 13 13 13 7 30 4 9 26 7 30 26 13 30 25 16 8 10 28 20 17 10 17 24 9 26 11 33 45 7 33 38 6 27 11 9 12 1 3 1 13 9 4 3 4 1 <1 3 <1 2 <1 <1 <1 <1 1 5 3 1 2 2 2 5 4 5 2 2 0 1 1 1 1 1 <1 2 1 1 1 4 3 4 6 3 1 2 2 2 <1 0 0 <1 6 5 2 2 1 <1 <1 <1 <.1 <1 <1 <1 0 <.1 <.1 <1 <1 <1 <1 <.1 <1 <1 <1 1 <1 <.1 <1 <.1 <1 <.1 <1 <1 <1 <1 <1 <1 <.1 <1 <.1 <1 <1 <.1 <1 <1 <1 <1 <1 <.1 <1 <1 <1 <1 0.19 1 <1 0.03 0.01 0.02 0.00 0.01 0.03 0.03 0.00 0.00 0.03 0.03 0.00 0.02 0.04 0.04 0.00 0.05 0.04 0.03 0.00 0.02 0.05 0.05 0.00 0.01 0.01 0.01 0.03 0.13 0.00 0.02 0.01 0.01 0.02 0.01 0.01 0.00 0.01 0.00 0.01 0.01 0.01 0.01 0.01 0.01 0.01 0.05 0.01 0.06 0.01 0.00 0.01 0.01 0.01 0.00 0.01 0.01 0.01 0.02 0.03 0.03 0.03 0.02 0.04 0.03 0.06 0.18 0.09 0.03 0.12 0.00 0.07 0.05 0.03 0.06 0.04 0.06 0.20 0.04 0.02 0.02 0.01 0.02 0.01 0.02 0.01 0.01 0.01 0.11 0.07 0.06 0.15 0.05 0.04 0.02 0.00 0.03 0.02 0.02 0.03 0.04 0.02 0.03 0.01 0.01 0.00 0 0.03 0.01 0.02 0.09 0.00 0.08 0.06 0.03 0.08 0.05 0.07 0.20 0.04 0.02 0.02 0.03 0.05 0.04 0.05 0.04 0.04 0.03 0.04 0.10 0.02 0.04 0.02 0.23 0.11 0.05 0.11 0.09 0.02 0.03 0.05 0.04 0.05 0.06 0.08 0.06 0.12 0.34 0.17 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-15 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 5 52 3 36 14 14 176 11 17 73 2 6 4 2 4 15 5 22 7 11 7 10 18 17 18 18 21 2 5 5 9 23 31 15 19 174 12 14 38 12 22 60 138 32 54 38 20.7 19 21 0.15 0.19 0.13 0.02 0.09 0.25 0.25 0.12 0.07 0.30 0.29 0.25 0.35 0.39 0.46 0.28 0.00 0.50 0.29 0.36 0.63 0.22 0.49 0.35 0.49 0.49 0.33 0.45 0.14 0.46 0.42 0.46 3.02 0.42 0.81 0.25 0.30 0.60 0.10 0.08 0.25 0.65 1.49 0.29 1.55 1.08 0.81 0.73 0.58 9 8 13 <1 9 14 14 12 7 30 5 9 7 6 6 12 10 12 5 9 9 20 17 20 22 16 25 6 5 8 21 36 14 16 16 9 8 10 10 10 15 36 9 72 50 203 86 237 4 164 248 248 226 237 180 783 63 186 121 121 163 198 148 250 86 119 78 89 133 152 132 156 168 358 130 399 125 383 707 93 143 115 110 125 172 132 220 171 423 74 425 297 12.6 12 12 201.6 208 196 16 1 0 <.1 0 1 1 0 1 2 9 5 0 8 4 8 2 0 0 7 5 <1 1 1 1 1 1 1 4 0 5 1 1 10 1 1 1 1 1 0 1 1 6 14 5 114 80 12.6 347 4 0.08 0.08 0.09 0.01 0.06 0.06 0.06 0.06 0.05 0.21 0.17 0.12 0.11 0.06 0.17 0.02 0.24 0.11 0.11 0.08 0.14 0.12 0.15 0.15 0.14 0.10 0.08 0.18 0.09 0.19 0.54 0.26 0.23 0.10 0.06 0.07 0.20 0.04 0.25 0.58 0.09 0.59 0.41 0.54 0.48 0.50 3 22 14 <1 10 12 5 6 39 16 22 33 18 2 0 0 0 2 1 2 3 2 0 35 14 8 17 37 0 1 4 1 1 29 16 0 92 24 11 8 48.59 50 0.03 0.03 0.11 0.00 0.08 0.11 0.11 0.08 0.02 0.04 0.24 0.00 0.16 0.05 0.05 0.01 0.02 0.05 0.00 0.04 0.04 0.04 0.37 0.14 0.37 0.02 0.26 0.50 0.50 0.40 0.08 0.03 0.08 0.00 0.05 0.05 0.05 0.06 0.10 0.25 0.02 0.25 0.05 0.02 0.06 0.00 0.02 0.01 0.01 0.02 0.02 0.01 0.04 0.01 0.01 0.06 0.12 0.12 0.11 0.11 0.07 0.04 0.02 0.05 0.01 0.00 0.04 0.02 0.02 0.02 0.02 0.02 0.08 0.09 0.07 0.01 0.01 0.01 0.08 0.05 0.14 0.07 0.06 0.51 2.22 0.72 0.64 0.60 0.77 0.20 0.15 1.00 0.11 0.10 0.02 0.01 0.01 0.01 0.03 0.10 0.21 0.92 0.00 0.23 0.31 0.54 0.90 0.21 0.31 0.17 0.17 0.16 0.09 0.23 0.16 1.35 0.38 1.08 0.02 0.09 0.02 0.03 0.03 0.02 0.04 0.04 0.01 0.08 0.03 0.01 0.02 0.03 0.02 0.03 0.03 0.03 0.04 0.02 0.05 0.03 0.12 0.18 0.02 0.06 0.03 0.02 0.10 0.04 0.02 0.02 0.04 0.09 0.02 0.08 0.06 0.12 0.12 0.09 0.24 0.93 0.27 0.79 0.80 0.64 0.82 0.26 0.27 0.20 0.32 0.25 0.38 0.37 0.35 0.37 0.37 0.32 0.58 0.34 0.46 0.33 0.85 2.01 0.37 0.29 0.25 0.28 0.37 0.27 0.13 0.12 0.18 0.37 0.06 1.20 0.84 0.97 1.15 0.93 0.01 0.05 0.02 0.02 0.02 0.02 0.05 0.03 0.04 0.02 0.02 0.09 0.10 0.09 0.09 0.09 0.12 0.18 0.02 0.16 0.04 0.23 0.56 0.03 0.04 0.03 0.04 0.06 0.06 0.05 0.05 0.12 0.01 0.13 0.09 0.07 0.13 0.02 17 2 39 1 27 37 38 30 55 27 58 3 4 4 4 4 12 10 15 1 1 12 7 6 6 6 29 20 4 9 1 0 0 13 33 17 5 29 17 6 24 38 19 61 43 16 6 70 3 48 62 62 54 48 43 38 5 6 4 4 118 7 5 8 1 2 17 28 9 12 9 9 13 8 8 9 1 3 10 16 21 4 42 50 51 26 38 12 27 3 12 8 134.1 116 121 6.92 22 22 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 <1 1 <.1 <1 <1 <1 <1 <1 <.1 <1 <1 1 <1 <1 1 0 0 0 <.1 <1 1 <1 <1 1 0 1 <1 <1 2 <1 <1 <1 1 <1 <1 <1 1 <.1 <1 <1 5.48 2 4 h a p p e n d i x h-16 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 1048 1049 1801 511 512 513 1805 14597 569 1806 2773 2736 515 570 579 510 32816 1052 514 1810 1053 1670 1108 1807 574 575 576 580 581 583 2730 584 585 587 588 590 16848 591 592 594 595 35611 16869 596 597 11710 600 8691 601 602 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans vegetables, legumes continued bamboo shoots boiled, drained canned, drained beans adzuki beans, boiled baked beans w/franks, canned baked beans w/pork in tomato sauce, canned baked beans w/pork in sweet sauce, canned black beans, boiled chickpeas, garbanzo beans, or bengal gram, boiled fordhook lima beans, frozen, boiled, drained french beans, boiled great northern beans, boiled hyacinth beans, boiled, drained lima beans, boiled, drained lima beans, baby, frozen, boiled, drained mung beans, sprouted, boiled, drained navy beans, boiled pinto beans, boiled, drained, no salt added pinto beans, frozen, boiled, drained red kidney beans, canned refried beans, canned shell beans, canned soybeans, boiled soybeans, green, boiled, drained white beans, small, boiled green string beans, canned, fat added in cooking yellow snap, string or wax beans, boiled, drained yellow snap, string or wax beans, frozen, boiled, drained beets whole, boiled, drained sliced, boiled, drained sliced, canned, drained pickled, canned with liquid beet greens, boiled, drained cowpeas or black-eyed peas, boiled, drained broccoli raw, chopped chopped, boiled, drained frozen, chopped, boiled, drained brocco ower, raw, chopped brussels sprouts boiled, drained frozen, boiled, drained cabbage raw, shredded boiled, drained, no salt added chinese (pak choi or bok choy), boiled w/salt, drained kim chee red, shredded, raw savoy, shredded, raw capers carrots raw raw, baby grated sliced, boiled, drained 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 1 1 1 1 1 1 1 2 8 1 2 1 2 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) 60 65 115 129 127 127 86 82 85 89 89 44 85 90 62 91 114 47 128 127 123 86 90 90 93 62 68 100 85 85 114 72 58 62 76 89 92 89 57 49 62 59 61 38 57 65 <.1 57 106 27 99 96 111 54 62 57 <.1 <.1 <.1 87 74 77 93 64 cup(s) 83 0.06 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) teaspoon(s) cup(s) item(s) cup(s) cup(s) 44 78 92 32 78 78 70 150 170 150 70 70 5 61 80 55 78 39 70 83 29 69 67 65 140 162 138 63 64 54 72 49 0.07 7 12 147 182 124 140 114 134 88 114 104 22 105 95 13 129 25 76 109 119 37 149 127 127 41 22 19 44 37 26 74 19 80 15 27 26 10 28 33 17 33 20 31 22 19 0 1 1 9 9 7 7 8 7 5 6 7 1 6 6 1 8 2 4 7 7 2 14 11 8 1 1 1 2 1 1 1 2 1 2 28 20 25 27 20 22 16 21 19 4 20 18 3 24 5 15 20 20 8 9 10 23 4 5 4 10 8 6 18 4 1 1 8 9 6 7 7 6 5 8 6 0 5 5 <1 6 0 4 8 7 4 5 4 9 2 2 2 2 2 1 3 2 <1 <1 <1 8 1 2 <1 2 <1 1 <1 <1 <1 <1 <.1 1 <1 <1 <1 2 <1 8 6 1 3 <1 <1 <1 <1 <1 <.1 <1 0.03 0.06 0.04 3.02 0.00 0.01 3.64 0.06 0.12 1.07 0.50 0.56 0.17 0.71 0.12 0.80 0.04 0.24 0.20 0.22 0.48 0.95 0.07 0.07 0.12 0.05 0.06 0.06 0.02 0.13 0.04 0.03 0.06 0.60 0.03 1.12 0.67 0.15 0.02 0.05 0.02 0.06 0.02 0.02 0.00 0.05 0.03 0.02 0.03 0.71 0.02 1.70 1.09 0.05 0.14 0.40 0.17 0.00 0.13 0.13 0.02 0.22 0.21 0.13 0.24 0.19 0.13 4.36 2.71 0.25 0.51 1.23 0.75 0.04 0.00 0.09 0.02 0.00 0.05 0.03 0.02 0.02 0.01 0.02 0.04 0.03 0.02 0.02 0.03 0.06 0.05 0.04 0.03 0.05 2.61 16.76 4.12 0.31 0.07 0.02 0.13 1 2 3 1 2 3 1 2 3 2 1 1 0 3 6 5 2 6 6 4 7 3 6 5 4 0 1 3 3 1 2 3 2 3 2 2 1 2 0 <1 <1 <1 <.1 <1 <1 <.1 1 <1 <1 <1 <.1 0 25 28 23 27.29 1 1 1 0.59 6 7 5 6.41 2 1 2 2.33 <1 <1 <1 0.14 0.02 0.06 0.02 0.01 0.08 0.06 0.01 0.08 0.04 0.04 0.02 0.01 0.00 0.02 0.02 0.02 0.02 0.00 0.03 0.01 0.01 0.03 0.02 0.01 0.05 0.02 0.02 0.01 0.00 0.00 0.01 0.01 0.01 0 0.02 0.13 0.05 0.04 0.20 0.16 0.04 0.29 0.13 0.15 0.09 0.03 0.00 0.06 0.05 0.06 0.08 0 0 0 0 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-17 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 8 9 9 0 0 0 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 5 32 62 71 77 23 40 26 56 60 18 27 25 7 64 17 24 31 44 36 88 131 65 24 29 33 16 14 13 12 82 0.14 0.21 2.30 2.22 4.15 2.10 1.81 2.37 1.55 0.96 1.89 0.33 2.08 1.76 0.40 2.26 0.75 1.27 1.61 2.10 1.21 4.42 2.25 2.54 0.81 0.80 0.59 0.79 0.67 1.55 0.47 1.37 2 3 60 36 44 43 60 39 36 50 44 18 63 50 9 54 20 25 36 42 18 74 54 61 12 16 16 23 20 14 17 49 320 52 612 302 2 5 9 553 0.28 0.43 2.04 2.40 380 557 7.41 336 305 239 258 327 346 114 485 370 63 335 111 304 329 338 134 443 485 414 425 1 6 59 5 2 1 14 26 6 1 58 39 436 378 409 1 13 2 1.90 0.96 1.25 0.63 0.57 0.78 0.17 0.67 0.50 0.29 0.96 0.19 0.32 0.70 1.48 0.33 0.99 0.82 0.98 0 1 0 5 5 1 0 1 9 0 0 3 16 7 1 0 0 0 0 0 13 0 7 0 0.01 0.02 0.13 0.07 0.41 0.59 0.03 0.02 0.07 0.07 0.18 0.09 0.82 1.16 0.06 0.09 0.11 0.06 1 2 139 39 0.07 0.13 0.06 0.63 0.09 29 0.06 0.21 0.04 0.08 0.05 0.44 0.43 0.11 0.06 47 128 0.10 0.29 0.05 0.43 0.11 141 0.06 0.12 0.14 0.02 0.12 0.06 0.03 0.18 0.08 0.13 0.13 0.03 0.04 0.13 0.23 0.21 0.25 0.12 0.58 0.04 0.01 0.77 0.00 0.04 0.30 0.05 0.05 0.05 0.04 0.08 0.05 0.06 0.06 0.07 0.05 0.11 0.02 0.07 0.25 0.14 0.05 0.91 0.48 0.60 0.21 0.88 0.69 0.50 0.48 0.82 0.30 0.58 0.40 0.25 0.34 1.13 0.24 0.10 0.09 0.10 0.01 0.16 0.10 0.03 0.15 0.06 0.09 0.03 0.18 0.06 0.20 0.05 0.11 100 266 0.26 129 0.01 0.40 0.05 0.18 0.03 187 85 305 259 126 168 654 2 6 77 65 165 300 174 0.22 0.32 0.35 0.30 0.18 0.30 0.36 5 7 2 2 1 1 276 0.05 0.28 0.06 0.38 0.03 0.02 0.24 0.06 0.26 0.04 0.03 0.02 0.01 0.01 0.08 0.04 0.03 0.03 1.30 0.04 0.03 0.03 0.05 0.21 0.33 0.28 0.13 0.28 0.36 0.07 0.06 0.05 0.06 0.10 18 66 90 20 22 14 18 127 146 16 65 14 22 46 100 123 21 16 80 68 26 31 10 0 1 0 3 4 4 0 1 11 1 1 2 9 5 7 1 7 <1 1 8 4 1 15 0 4 6 3 4 3 3 3 18 105.59 0.92 42.9 344.85 3.29 0.84 65.17 0.08 0.18 0.12 1.15 0.05 104.77 1.81 21 31 30 11 28 20 33 47 158 145 32 25 20 26 18 23.39 0.32 0.52 0.56 0.23 0.94 0.37 0.41 0.26 1.77 1.28 0.56 0.28 0.18 0.71 0.17 0.26 9 16 12 6 16 14 11 12 19 27 11 20 7 8 7 7.8 139 229 131 96 247 225 172 146 631 375 170 161 15 32 10 7 16 12 13 12 459 995 19 20 105 195 190 177 183.3 42 62 38 45.24 0.18 0.35 0.26 0.20 0.26 0.19 0.13 0.14 0.29 0.36 0.15 0.19 0.15 0.14 0.13 0.15 15 76 52 0 30 36 6 11 360 39 35 367 552 333 1914.9 0.03 0.05 0.05 0.03 0.08 0.08 0.04 0.09 0.05 0.07 0.04 0.05 0.04 0.02 0.04 0.05 0.34 1.13 1.21 0.01 0.34 0.40 0.10 0.18 0.15 0.08 0.12 0.40 0.36 0.80 0.05 0.10 0.07 0.03 0.06 0.09 0.03 0.08 0.11 0.10 0.05 0.02 0.04 0.03 0.03 0.03 0.28 0.43 0.42 0.23 0.47 0.42 0.21 0.42 0.73 0.75 0.29 0.21 0.60 0.44 0.54 0.5 0.08 0.16 0.12 0.07 0.14 0.22 0.07 0.17 0.28 0.34 0.15 0.13 0.08 0.08 0.08 0.11 28 84 52 18 47 78 30 30 70 88 13 56 12 26 11 10.92 39 51 37 28 48 35 23 30 44 80 40 22 4 7 3 2.8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <1 1 8 6 6 1 3 1 1 4 1 2 2 <1 5 1 1 2 2 1 6 1 1 <1 <1 1 1 <1 1 1 2.06 1 1 1 1 <1 1 1 1 <1 1 <.1 1 <.1 0.54 h a p p e n d i x h-18 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans da + code 1055 32725 605 606 607 609 608 1056 1057 610 611 29614 612 614 615 618 16870 2734 620 1066 621 8784 29313 623 1071 1072 1073 1074 522 1075 624 625 626 628 629 1665 15585 8700 630 1079 1080 15587 2743 29319 2744 632 32742 16866 633 635 h x i d n e p p a vegetables, legumes continued juice, canned cassava or manioc cauli ower raw, chopped, boiled, drained frozen, boiled, drained celery diced stalk chard swiss chard, raw swiss chard, boiled, drained collard greens boiled, drained frozen, chopped, boiled, drained corn yellow corn, fresh, cooked yellow sweet corn, boiled, drained yellow sweet corn, frozen, boiled, drained yellow creamed sweet corn, canned cucumber cucumber, kim chee dandelion greens raw chopped, boiled, drained eggplant, boiled, drained endive or escarole, chopped, raw jicama or yambean kale raw frozen, chopped, boiled, drained kohlrabi raw boiled, drained leeks raw boiled, drained lentils boiled sprouted lettuce butterhead, boston, or bibb butterhead leaves iceberg iceberg, chopped looseleaf romaine, shredded mushrooms crimini (about 6) enoki mushrooms, raw mushrooms, boiled, drained mushrooms, canned, drained portobello, raw shiitake, cooked mustard greens raw frozen, boiled, drained okra sliced, boiled, drained frozen, boiled, drained, no salt added batter coated, fried onions raw, chopped chopped, boiled, drained 1 2 1 2 1 2 1 2 1 2 1 2 2 1 1 2 1 2 1 2 1 1 2 1 2 1 2 1 4 1 2 1 1 2 1 2 1 1 2 1 1 2 1 1 2 1 1 2 1 2 1 1 11 1 1 1 1 3 30 1 2 1 2 1 2 1 1 2 1 1 2 1 2 1 2 11 1 2 1 2 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) piece(s) cup(s) cup(s) cup(s) cup(s) ounce(s) item(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) piece(s) cup(s) cup(s) 50 62 90 60 80 36 88 95 85 100 82 82 128 75 75 55 53 48 53 65 67 65 63 101 72 68 47 47 43 49 59 57 59 135 83 123 74 89 52 99 77 55 83 55 55 56 56 85 90 35 78 78 85 73 56 75 80 92 83 80 106 74 47 69 52 53 79 53 53 54 53 28 80 32 71 71 30 61 51 70 74 84 55 71 93 123 103 109 61 49 165 1 1 1 1 1 <1 1 1 2 2 3 11 39 3 3 3 2 2 1 4 5 6 1 2 1 2 2 1 1 1 2 3 2 <1 <1 <1 <1 <1 <1 <1 <.1 <.1 <1 <1 46 58 85 58 76 33 81 87 75 13 14 17 8 11 7 18 25 31 0.06 57 107.37 89 3.3 3 24.96 21 2.78 2 1.27 1 66 92 11 16 25 17 17 9 25 34 20 36 24 54 16 115 82 7 11 6 6 8 10 4 31 8 22 20 3 40 15 14 18 26 160 34 47 2 2 <1 1 1 1 <1 1 <1 2 2 2 1 1 <1 9 7 1 1 <1 <1 1 1 3 2 1 2 1 4 1 2 2 1 2 2 1 1 16 23 3 4 5 3 4 2 6 7 3 8 6 13 4 20 17 1 2 1 1 2 2 2 6 1 4 4 3 10 3 2 4 5 13 8 11 2 2 <1 1 2 2 1 2 3 1 1 5 1 2 1 8 0 1 1 1 1 1 1 0 2 <1 2 2 0 2 2 2 2 3 2 1 1 1 1 <.1 <.1 <1 <1 <1 <1 <.1 <1 <1 <1 <.1 <1 <1 <1 <1 <1 <1 <.1 <.1 <.1 <1 0.00 <1 <1 <1 <1 0.00 <1 <1 <1 <1 <1 11 <.1 <1 0.03 0.08 0.02 0.04 0.03 0.03 0.03 0.01 0.01 0.04 0.05 0.19 0.16 0.08 0.08 0.03 0.02 0.09 0.08 0.02 0.03 0.01 0.06 0.04 0.02 0.01 0.04 0.01 0.05 0.04 0.02 0.02 0.01 0.01 0.01 0.02 0.00 0.04 0.02 0.05 0.03 0.00 0.04 0.01 0.01 0.04 0.07 1.50 0.02 0.03 0.01 0.08 0.01 0.02 0.01 0.02 0.03 0.01 0.01 0.02 0.02 0.37 0.31 0.16 0.16 0.00 0.00 0.01 0.01 0.01 0.00 0.00 0.03 0.02 0.01 0.01 0.00 0.00 0.06 0.08 0.00 0.01 0.00 0.00 0.00 0.01 0.00 0.01 0.00 0.01 0.00 0.00 0.05 0.05 0.08 0.02 0.05 2.80 0.02 0.03 0.09 0.05 0.05 0.13 0.09 0.05 0.06 0.03 0.02 0.16 0.18 0.59 0.49 0.26 0.25 0.04 0.03 0.17 0.14 0.04 0.05 0.03 0.23 0.15 0.06 0.04 0.15 0.06 0.17 0.17 0.06 0.10 0.03 0.03 0.05 0.09 0 0.14 0.05 0.14 0.09 0 0.02 0.02 0.04 0.04 0.07 6.37 0.05 0.08 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-19 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 40 0 0 0 0 0 2 0 0 30 16 11 10 15 24 32 18 51 133 179 2.12 2 2 4 12 7 103 74 3 27 8 90 90 32 21 53 16 19 19 19 29 11 11 20 19 0.67 1 1 5 9 0.36 2 58 76 62 88 54 18 23 0.57 0.28 0.22 0.20 0.37 0.12 0.16 0.65 1.98 1.10 0.95 0.6 0.50 0.39 0.49 0.21 3.62 1.71 0.95 0.12 0.44 0.39 1.14 0.61 0.54 0.33 1.87 0.57 3.30 2.47 0.69 1.02 0.19 0.19 0.48 0.55 0.80 0.18 1.36 0.62 0.32 0.82 0.84 0.22 0.62 1.13 0.15 0.26 17 22 8 6 8 7 9 29 75 19 26 31.81 26 23 22 10 6 20 13 5 8 8 23 12 26 16 25 7 36 28 7 11 4 4 7 8 14 3 9 12 10 18 10 29 47 32 8 12 359 279 152 88 125 157 208 136 480 110 213 36 14 15 9 16 48 64 77 157 15 43 247.59 242.45 204 191 172 111 88 219 122 59 165 98 299 209 473 281 160 45 365 248 132 196 84 84 109 139 33 343 110 278 101 10 85 199 104 108 215 170 115 177 14 1 365 2 766 42 23 <1 12 3 29 10 27 17 18 5 2 8 3 4 5 5 16 5 3 1 2 332 3 14 19 5 3 110 2 3 0.22 0.35 0.14 0.11 0.12 0.08 0.10 0.13 0.29 0.22 0.23 0.47 0.39 0.52 0.68 0.15 0.38 0.23 0.15 0.06 0.41 0.10 0.29 0.12 0.04 0.26 0.11 0.03 1.26 1.16 0.11 0.17 0.09 0.09 0.10 0.13 0 0.51 0.18 0.68 0.56 0 0.96 0.11 0.15 0.34 0.57 0.44 0.13 0.22 1176 1 1 1 0 13 18 110 268 386 489 21.87 11 8 5 4 137 260 1 57 1 515 478 3 2 74 1 0 2 92 137 9 9 208 163 0 0 0 0 0 295 266 11 16 0 0 0.11 0.09 0.03 0.03 0.03 0.01 0.02 0.01 0.03 0.04 0.04 0.21 0.18 0.02 0.03 0.02 0.02 0.11 0.07 0.04 0.04 0.01 0.07 0.03 0.07 0.03 0.05 0.01 0.17 0.18 0.03 0.05 0.02 0.02 0.04 0.04 0.08 0.03 0.06 0.07 0.03 0.05 0.03 0.11 0.09 0.16 0.04 0.04 1.43 0.20 0.04 0.04 0.05 0.16 0.22 0.68 1.65 0.84 1.06 0.09 0.07 0.06 0.09 0.02 0.36 2.65 1.79 0.20 0.23 0.30 0.60 0.65 0.43 0.82 0.11 0.10 0.15 0.10 0.10 0.16 0.07 0.01 0.00 0.01 0.01 0.01 1.13 1.01 0.22 0.29 1.51 0.02 0.02 0.07 0.05 0.03 0.03 0.05 0.03 0.05 0.03 0.08 0.10 0.10 0.07 0.06 0.05 0.07 0.02 0.02 0.14 0.09 0.01 0.04 0.02 0.09 0.07 0.03 0.02 0.03 0.01 0.07 0.10 0.03 0.05 0.01 0.01 0.05 0.04 0.09 0.15 0.23 0.02 0.12 0.06 0.04 0.04 0.11 0.13 0.02 0.02 0.47 0.88 0.26 0.25 0.28 0.19 0.26 0.14 0.32 0.55 0.54 1.6 1.32 1.08 1.23 0.07 0.35 0.45 0.27 0.29 0.21 0.13 0.67 0.44 0.54 0.32 0.36 0.10 1.05 0.87 0.20 0.29 0.07 0.07 0.21 0.18 3.28 1.35 3.48 1.24 1.09 0.45 0.19 0.70 0.72 1.29 0.07 0.18 0.27 0.09 0.11 0.11 0.08 0.04 0.06 0.04 0.07 0.12 0.10 0.05 0.05 0.08 0.08 0.03 0.08 0.14 0.08 0.04 0.01 0.03 0.18 0.06 0.20 0.13 0.21 0.06 0.18 0.15 0.05 0.07 0.03 0.03 0.05 0.04 0.04 0.04 0.07 0.05 0.12 0.10 0.08 0.15 0.04 0.11 0.12 0.14 5 28 29 27 37 22 29 5 8 88 65 38 29 58 5 17 15 7 7 75 8 19 9 22 10 57 13 179 77 40 60 31 31 21 77 27 6 14 9 15 105 53 37 134 34 15 16 10 21 23 27 28 2 2 11 16 17 22 6.16 5 3 6 2 3 19 9 1 3 13 80 16 84 45 11 2 1 13 2 3 2 2 10 14 0 11 1 3 0 0 <1 39 10 13 11 9 5 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <.1 0 0 0 0 0 0 0 0 <.1 0 0 1 1 <1 <1 1 <1 <1 <1 1 <1 1 <1 1 1 <1 <1 <1 <.1 <1 <1 1 1 1 1 1 <1 3 <1 <1 <1 <1 <1 <1 <1 14 3 9 3 18 1 <1 <1 1 <1 1 h a p p e n d i x h-20 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 2748 16850 636 1081 16860 637 638 639 641 35694 1082 1083 640 2750 29324 643 644 1664 1663 1086 8703 1087 5791 645 1088 5794 647 5795 2759 5804 2760 1089 1090 648 649 1091 653 652 1097 1093 1094 1773 656 2498 8731 657 1099 658 1102 1104 1106 1670 2825 2824 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans vegetables, legumes continued frozen, boiled, drained red onions, sliced, raw scallions, green or spring onions onion rings, breaded & pan fried, frozen, heated palm hearts, cooked parsley, chopped parsnips, sliced, boiled, drained peas green peas, canned, drained green peas, frozen, boiled, drained pea pods, boiled w/salt, drained peas & carrots, canned w/liquid peas & carrots, frozen, boiled, drained snow or sugar peas, raw snow or sugar peas, frozen, boiled, drained split peas, sprouted peppers green bell or sweet, raw green bell or sweet, boiled, drained green hot chili green hot chili, canned w/liquid jalapeno, canned w/liquid yellow bell or sweet poi potatoes baked, esh & skin baked, esh only baked, skin only boiled, drained, skin & esh boiled, esh only boiled in skin, drained, esh only microwaved microwaved, skin only microwaved in skin, esh only au gratin, prepared w/butter au gratin mix, prepared w/water, whole milk, & butter french fried, deep fried, prepared from raw french fried, frozen, heated hashed brown mashed, from dehydrated granules w/milk, water, & margarine mashed, w/margarine & whole milk potato puffs, frozen, heated scalloped, prepared w/butter scalloped mix, prepared w/water, whole milk, & butter pumpkin boiled, drained canned radicchio raw raw, leaves radishes rutabaga, boiled, drained sauerkraut, canned seaweed kelp spirulina, dried shallots soybeans boiled dry roasted roasted, salted 1 2 1 2 2 11 1 2 1 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 1 2 1 2 1 1 2 1 1 2 1 1 1 2 1 1 1 1 2 1 2 1 2 14 14 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 10 6 1 2 1 2 1 2 1 2 3 1 2 1 2 1 2 cup(s) cup(s) item(s) item(s) cup(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) item(s) cup(s) item(s) cup(s) item(s) item(s) cup(s) item(s) item(s) item(s) cup(s) cup(s) cup(s) item(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) item(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) cup(s) cup(s) cup(s) 106 58 30 78 73 4 78 85 80 80 128 80 32 80 60 75 68 45 68 68 186 122 202 61 58 150 78 136 202 58 78 123 114 70 70 78 105 105 64 123 114 123 123 40 80 27 85 114 41 8 30 86 86 86 98 52 27 22 51 3 63 69 64 71 112 69 28 69 37 70 62 39 63 60 171 87 144 46 27 116 60 105 146 37 57 91 90 32 40 37 80 79 34 99 90 115 110 37 75 26 76 105 33 <1 24 30 22 10 318 75 1 55 59 62 34 48 38 13 42 77 15 19 18 14 18 50 136 220 57 115 129 67 118 212 77 78 162 106 190 140 207 122 119 142 105 106 25 42 9 18 4 33 22 17 22 22 1 1 1 4 2 <1 1 4 4 3 3 2 1 3 5 1 1 1 1 1 2 <1 5 1 2 3 1 3 5 3 2 6 3 3 2 2 2 2 2 4 2 1 1 1 1 <1 1 1 1 4 1 7 5 2 30 19 <1 13 11 11 6 11 8 2 7 17 3 5 4 3 3 12 33 51 13 27 30 16 27 49 17 18 14 15 24 22 27 17 18 20 13 15 6 10 2 4 1 7 5 4 2 5 2 1 1 1 1 <1 3 3 4 2 3 2 1 2 0 1 1 1 1 2 2 <1 4 1 5 2 1 2 5 4 1 2 1 2 2 2 1 2 2 2 1 1 4 <1 1 <1 2 3 1 <1 0 <1 <.1 <.1 21 <1 <.1 <1 <1 <1 <1 <1 <1 <.1 <1 <1 <1 <1 <.1 <.1 1 <1 <1 <1 <.1 <.1 <1 <.1 <1 <1 <.1 <.1 9 5 10 5 10 5 4 7 5 5 <.1 <1 <.1 <1 <1 <.1 <1 <1 <1 1 <.1 0.05 1 2 148.77 14.31 8.53 28 34 29 30 388 405 5.15 7 15 7.71 19 22 0.02 0.02 0.01 6.70 0.03 0.01 0.04 0.05 0.04 0.04 0.06 0.06 0.01 0.06 0.07 0.04 0.02 0.01 0.01 0.07 0.06 0.04 0.05 0.02 0.02 0.04 0.02 0.04 0.05 0.02 0.02 5.80 0.01 0.01 0.01 8.49 0.00 0.01 0.09 0.03 0.02 0.02 0.03 0.03 0.01 0.03 0.04 0.01 0.01 0.00 0.00 0.04 0.03 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.63 0.04 0.04 0.02 3.99 0.07 0.00 0.04 0.14 0.10 0.08 0.16 0.16 0.03 0.13 0.20 0.05 0.07 0.05 0.04 0.35 0.21 0.07 0.09 0.03 0.02 0.06 0.03 0.06 0.09 0.02 0.03 0.34 2.94 1.34 0.15 1.93 0.88 1.11 1.27 1.05 3.26 2.76 4.21 3.33 3.13 2.05 1.83 2.79 1.27 2.97 0.55 2.78 1.41 1.27 0.51 0.20 2.99 1.38 0.22 0.00 0.02 0.04 0.09 0.01 0.08 0.07 0.02 0.16 0.01 0.05 0.18 0.02 0.05 0.01 0.02 0.04 0.10 0.20 0.01 1.11 2.69 3.16 0.01 0.05 0.00 0.01 0.00 0.02 0.01 0.04 0.05 0.00 1.7 4.11 4.82 4.35 10.50 12.33 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-21 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 28 17 0 0 0 2 1 0 15 13 0 0 0 0 0 0 0 0 0 0 0 0 0 17 11 22 24 13 5 29 17 19 34 29 18 14 47 22 7 6 8 5 16 20 19 20 3 20 13 6 7 22 27 4 146 94 9 6 11 34 21 19 70 41 18 32 8 15 7 41 34 68 9 11 87.72 120 119 0.32 0.13 0.44 1.32 1.23 0.24 0.45 0.81 1.22 1.58 0.96 0.75 0.66 1.92 1.36 0.25 0.31 0.54 0.34 1.28 0.86 1.07 2.75 0.21 4.08 1.27 0.24 0.42 2.50 3.45 0.32 0.78 0.36 1.02 0.87 0.43 0.22 0.27 1.00 0.70 0.43 0.70 1.70 0.23 0.46 0.09 0.45 1.67 1.16 2.14 0.36 4.42 3.40 3.35 6 6 6 15 7 2 23 14 18 21 18 13 8 22 34 7 7 11 10 10 22 29 55 15 25 34 16 30 55 21 20 25 17 28 15 27 21 20 12 23 16 11 28 5 10 3 20 15 49 15 6 115 90 83 101 1318 21 286 147 88 192 128 126 63 174 229 130 113 153 127 131 394 223 844 239 332 572 256 515 903 377 321 485 13 2 5 293 10 2 8 214 58 192 332 54 1 4 12 2 1 3 798 1136 4 15 16 3 12 7 4 5 16 9 5 530 0.07 0.11 0.12 0.33 2.72 0.04 0.20 0.60 0.54 0.30 0.74 0.36 0.09 0.39 0.63 0.10 0.08 0.14 0.12 0.23 0.32 0.27 0.65 0.18 0.28 0.47 0.21 0.41 0.73 0.30 0.26 0.85 249 499 0.27 731 293 449 163 342 243 463 8 21 267 181 350 477 410 0.53 0.28 0.37 0.25 0.32 0.19 0.49 231 388 0.28 282 252 121 242 63 277 193 36 102 100 1 6 9 18 11 17 751 94 79 4 0.28 0.21 0.25 0.50 0.08 0.30 0.22 0.50 0.15 0.12 0.98 4.10 2.70 0 0 15 9 16 0 23 84 43 368 374 17 53 5 13 10 27 24 58 19 4 0 0 1 0 0 0 0 0 0 78 59 0 0 0 49 43 0 39 40 306 953 <1 1 0 0 1 2 2 18 0.86 0 9 0.02 0.02 0.02 0.22 0.03 0.00 0.06 0.10 0.23 0.10 0.09 0.18 0.05 0.05 0.14 0.04 0.04 0.04 0.01 0.03 0.05 0.16 0.22 0.06 0.07 0.15 0.08 0.14 0.24 0.04 0.10 0.08 0.02 0.10 0.08 0.13 0.09 0.10 0.13 0.08 0.02 0.04 0.03 0.01 0.01 0.00 0.07 0.02 0.02 0.18 0.02 0.13 0.37 0.09 0.01 0.01 0.17 0.37 0.03 0.78 0.03 0.02 0.31 0.42 0.12 0.38 0.28 0.36 0.31 0.47 0.47 2.80 0.02 0.02 0.01 0.03 0.01 0.02 0.11 0.13 0.00 0.04 0.07 0.08 0.06 0.07 0.05 0.03 0.10 0.09 0.02 0.02 0.04 0.03 0.03 0.05 0.05 0.07 0.01 0.06 0.03 0.01 0.03 0.06 0.04 0.02 0.14 0.15 0.09 0.16 2.82 0.62 0.05 0.56 0.62 1.18 0.43 0.74 0.92 0.19 0.45 1.85 0.36 0.32 0.43 0.54 0.27 1.66 1.34 3.32 0.85 1.78 2.13 1.02 1.96 3.46 1.29 1.27 1.22 0.07 0.07 0.02 0.06 0.53 0.00 0.07 0.05 0.09 0.12 0.11 0.07 0.05 0.14 0.16 0.17 0.16 0.13 0.10 0.13 0.31 0.33 0.70 0.18 0.36 0.44 0.21 0.41 0.69 0.29 0.25 0.21 0.09 1.07 0.05 0.09 0.08 0.01 0.54 0.44 0.15 0.05 0.02 0.03 0.09 0.05 0.05 0.11 1.90 1.46 1.80 0.91 1.23 1.38 1.29 0.33 0.22 0.37 0.17 0.26 0.15 0.22 0.06 1.17 0.05 0.98 1.30 0.90 1.81 0.00 0.27 0.11 0.35 0.38 0.30 0.78 0.10 0.07 0.01 0.02 0.01 0.03 0.02 0.06 0.28 0.01 0.24 0.65 0.12 0.51 0.45 0.10 0.20 0.07 0.61 0.16 0.19 0.96 0.06 0.34 0.91 1.21 0.05 0.07 0.02 0.05 0.02 0.09 0.15 0.00 0.03 0.10 0.2 0.19 0.18 14 11 19 52 15 6 45 37 47 23 23 21 13 28 86 8 11 10 7 10 48 26 22 5 13 15 7 14 24 10 9 13 8 13 8 12 8 9 11 13 11 11 15 24 48 7 13 27 73 7 10 3 4 6 1 5 5 10 8 8 38 8 6 19 18 6 60 51 109 46 7 341 5 26 8 8 18 6 18 31 9 12 12 4 21 7 10 7 11 4 13 4 6 5 3 6 4 16 17 1 1 2 46.43 176 181 1.46 4 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <.1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <1 3 <.1 1 1 1 1 1 1 <1 1 <1 0 <1 <1 <1 <1 1 1 2 <1 <1 <1 <1 1 <1 <1 3 3 <1 <1 6 1 <1 2 2 <1 <1 <1 1 <1 1 1 <1 1 <1 6.27 17 16 h a p p e n d i x 73.95 196 125 442.89 1173 1264 0.86 2 140 h-22 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans da + code 30282 8739 1813 2838 13844 13843 1816 1817 13841 13842 1671 659 663 660 661 662 8470 1662 29702 1661 29451 32773 29700 29703 1660 29704 664 665 1112 1113 666 667 668 670 2765 1136 32785 8774 8777 671 16846 3952 1118 675 75 1699 1700 1125 1120 8778 8783 677 678 679 h x i d n e p p a vegetables, legumes continued soup (miso) sprouted, stir fried soy products soy milk tofu, dried, frozen (koyadofu) tofu, extra rm tofu, rm tofu, rm, w/calcium sulfate & magnesium chloride (nigari) tofu, fried tofu, silken tofu, soft tofu, soft, w/calcium sulfate & magnesium chloride (nigari) spinach raw, chopped canned, drained chopped, boiled, drained chopped, frozen, boiled, drained leaf, frozen, boiled, drained trimmed leaves squash acorn, baked acorn, boiled, mashed butternut, baked butternut, frozen, boiled butternut, frozen, boiled, mashed, no salt added crookneck & straightneck, boiled, drained hubbard, baked hubbard, boiled, mashed spaghetti, boiled, drained, or baked summer, all varieties, sliced, boiled, drained winter, all varieties, baked, mashed zucchini, boiled, drained zucchini, frozen, boiled, drained sweet potatoes baked, peeled boiled, mashed candied, home recipe canned, vacuum pack frozen, baked yams, baked or boiled, drained taro shoots, cooked, no salt added tomatillo raw raw, chopped tomato fresh, ripe, red fresh, cherry diced, red boiled, red juice, canned juice, no salt added paste, canned puree, canned sauce, canned stewed, canned, red sun dried sun dried in oil, drained turnips turnips, cubed, boiled, drained turnip greens, chopped, boiled, drained turnip greens, frozen, chopped, boiled, drained 1 3 1 3 3 3 3 3 3 3 3 1 1 2 1 2 1 2 1 2 1 1 2 1 2 1 2 1 2 1 2 1 2 v 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 2 1 2 1 5 1 2 1 2 1 2 1 2 2 1 4 1 4 1 2 1 2 1 4 1 2 1 2 1 2 cup(s) ounce(s) cup(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) item(s) item(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) 240 85 240 85 79 79 85 85 91 91 85 30 108 90 95 95 32 103 123 103 132 27 100 82 84 84 27 85 110 90 116 122 <1 90 103 118 78 0.08 87 107 72 90 103 90 113 100 166 84 100 88 68 70 68 66 123 85 90 120 122 122 33 63 61 128 27 28 78 72 82 84 91 85 107 76 133 56 76 65 48 67 62 60 0.11 0.07 85 113 115 115 24 55 55 117 4 15 73 67 74 218 57 214 5 0.07 43 85 106 118 408 80 80 6 11 9 41 8 8 8 8 11 12 2 2 2 1 3 6 1 1 65.48 230 30 30 6.83 15 6 6 2.52 9 0 1 0.34 3 1 1 3 6 5 26 4 4 3.79 17 1 1 0.59 0.84 0.51 3.73 0.50 0.50 0.54 2.48 0.50 0.50 1.05 1.37 0.78 5.70 0.87 0.87 0.83 3.79 0.51 1.00 1.47 3.41 2.00 14.57 2.60 2.17 2.14 9.69 1.52 2.00 0.07 51.88 5.57 1.53 0.17 3.13 0.45 0.69 1.76 7 25 21 30 30 3 57 42 41 51 47 18 51 35 21 18 38 14 19 90 126 115 91 88 79 10 22 21 22.13 17.85 16 22 21 21 27 24 20 33 70 59 17 14 24 1 3 3 4 4 1 1 1 1 2 1 1 4 3 5 5 <.1 15 11 11 13 12 1 3 2 4 4 3 5 3 3 2 0 <1 1 <1 <1 <1 <.1 <1 <.1 <.1 <.1 <.1 0.02 0.09 0.04 0.09 0.09 0.03 0.02 0.02 0.02 0.00 0.02 0.01 0.00 0.00 0.01 0.01 0.01 0.01 0.05 0.23 0.10 0.20 0.20 0.06 0.04 0.04 0.04 0.02 0.00 0.03 0.81 3 2 1 3.87 11 8 5 1.25 0 3 1 0.27 1 <1 <1 1 1 1 1 2 2 1 2 2 1 1 1 1 1.08 0.72 1 1 1 1 1 1 1 1 4 1 1 1 3 4 9 4 4 21 29 23 21 21 19 2 4 4 4.82 3.94 4 5 5 5 6 6 5 8 15 6 4 3 4 1 3 1 1 3 4 2 2 2 3 0 1 1 1.47 0.93 1 1 <1 <1 1 1 1 1 3 2 2 3 3 <1 <1 <.1 <1 <1 <1 3 <1 <1 <.1 <.1 1 1 0.24 0.28 <1 <1 <.1 <.1 <1 <1 <1 <1 1 4 <.1 <1 <1 0.05 0.13 0.09 0.05 0.06 0.13 0.01 0.03 0.03 0.05 1.13 0.04 0.02 0.02 0.01 0.09 0.09 0.05 0.03 0.04 0.02 0.01 0.01 0.04 0.02 0.02 0.03 0.12 0.52 0.01 0.04 0.02 0.05 0.03 0.02 0.02 0.05 0.00 0.01 0.00 0.00 0.53 0.01 0.00 0.00 0.00 0.11 0.10 0.06 0.04 0.05 0.02 0.01 0.01 0.03 0.02 0.02 0.04 0.13 2.38 0.00 0.01 0.11 0.27 0.18 0.10 0.12 0.27 0.02 0.06 0.06 0.10 0.12 0.09 0.05 0.04 0.02 0.28 0.28 0.16 0.11 0.12 0.05 0.03 0.03 0.07 0.05 0.06 0.10 0.30 0.57 0.03 0.07 0.08 0.02 0.14 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-23 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 64 70 10 310 60 60 137.78 316 300 300 1.89 0.34 1.39 8.28 1.08 1.08 1.23 4.14 0.73 0.72 37 82 46 50 78 52 361 482 338 17 39.12 51 35 33 149.68 124 988 12 29 5 0 0 6.8 14 65 65 0.87 1.79 0.55 4.17 0.85 1.69 1 5 22 0 0 0.85 1 0 0 0.06 0.36 0.39 0.42 0.07 0.14 0.96 3.24 0.03 0.03 0.16 0.16 0.17 0.27 0.08 0.04 2.61 0.94 0.35 1.01 0 0.09 0.17 0.14 0.10 0.24 0.05 0.08 57 108 5 78 28.06 23 4 10 0 1 0 0 0.17 0 0 0 94.4 0.94 22.96 102.05 6.8 0.54 0.85 0.03 0.01 0.03 0.45 0.04 37.42 0.17 30 138 122 145 145 25 45 32 42 25 23 18.2 17 12 16 24 23 12 19 38 45 22 22 31 10 10 5 5 12.3 4.25 9 13 12 12 12 11 8 43 30 13 26 99 0.81 2.49 3.21 1.86 1.86 2.13 0.95 0.69 0.62 0.77 0.70 0.41 0.48 0.33 0.26 0.32 0.45 0.32 0.54 0.69 1.20 0.95 0.89 0.48 0.36 0.29 0.42 0.41 0.33 0.37 0.24 0.82 0.52 0.52 0.98 1.11 0.62 1.70 2.45 0.74 0.14 0.58 125 1.59 24 82 78 78 78 25 44 32 30 12 11 167 375 419 287 287 134 448 322 291 176 162 24 29 63 92 92 38 4 4 4 3 2 0.16 0.50 0.68 0.47 0.47 0.18 0.17 0.13 0.13 0.16 141 531 472 573 573 22 50 572 0.02 0.02 0.09 0.07 0.07 0.03 0.17 0.12 0.07 0.07 0.61 2.10 1.87 3.36 3.36 1.32 0.06 0.15 0.21 0.17 0.17 0.06 0.01 0.01 0.02 0.05 0.22 0.42 0.44 0.42 0.42 0.18 0.90 0.65 0.99 0.61 0.06 0.11 0.22 0.13 0.13 0.07 0.20 0.14 0.13 0.09 0.14 406 0.05 0.05 0.56 0.08 58 106 131 115 115 <.1 19 13 19 22 19 8 16 9 2 2 8 11 8 15 5 4 18.2 23 15 9 183.73 367 253 91 1.73 8 6 14 22 13 20 15 27 30 9 22 18 12 6 14 13 173 448 228 219 475 382 159 312 332 458 241 182 177 13.52 9.35 10 11 13 13 14 14 10 15 52 22 7 16 21 291.51 188.69 213 262 279 279 333 274 203 264 925 430 138 146 184 1 1 3 2 36 45 59 53 7 5 1 1 1 6.15 7.65 5 13 328 12 259 249 321 282 566 73 12 21 12 0.25 0.15 0.12 0.16 0.35 0.23 0.16 0.23 0.32 0.33 0.13 0.18 0.26 0.14 0.38 0.15 0.15 0.2 0.07 0.15 0.17 0.18 0.18 0.21 0.23 0.12 0.22 0.54 0.21 0.09 0.10 29.46 310 236 5 10 268 50 11 961 1310 176 399 722 4 2 4 4 76.26 52.7 38 29 28 28 25 16 10 11 12 18 0 274 0.04 0.08 0.05 0.03 0.04 0.02 0.04 0.05 1.45 0.09 0.02 0.04 0.06 0.06 0.03 0.03 0.03 0.04 0.05 0.03 0.04 0.06 0.06 0.02 0.02 0.01 0.06 0.14 0.05 0.02 0.03 0.14 0.09 0.13 0.12 0.11 0.14 0.71 1.56 1.00 0.68 0.26 0.26 0.25 0.66 0.46 0.49 0.67 0.39 0.39 1.41 1.23 1.27 1.06 0.00 0.02 1.35 0.03 0.05 0.03 0.02 0.04 0.07 0.04 0.05 0.11 0.08 0.04 0.06 0.05 0.02 0.04 0.02 0.02 0.02 0.03 0.02 0.03 0.04 0.04 0.05 0.05 0.04 0.04 0.13 0.11 0.02 0.05 0.39 0.57 0.39 0.63 0.46 0.51 0.39 0.44 1.49 0.89 0.33 0.74 0.49 0.38 0.57 1.26 1.22 0.73 0.53 0.53 0.64 0.82 0.82 1.01 0.92 0.60 0.91 2.44 1.00 0.23 0.30 0.09 0.18 0.12 0.08 0.06 0.17 0.07 0.05 0.29 0.27 0.03 0.19 0.16 0.16 0.08 0.04 0.04 0.09 0.07 0.07 0.09 0.14 0.14 0.07 0.08 0.06 0.02 0.09 0.09 0.05 0.13 0.34 441 0.04 2.18 0.06 0.38 0.05 19.93 16 12 6 7.28 10 8 3 18 21 15 9 6 10 9 17 19 11 2 5 5 18.45 14 16 24 24 4 7 6 6 18 6 7 85 32 5 10 4 4 20 21 6 26 8 8 13 8 8 15.62 16.23 11 27 22 22 7 7 4 10 11 28 9 20 18 <1 0 0 0 0 0 0 0 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 3 46 7.99 24 7.56 <1 2 1 5 5 1 <1 1 1 1 0.17 1 <1 <1 <1 <1 <1 <1 <1 <1 1 1 1 <1 1 <1 <1 0 0 1 <1 <1 2 3 <1 1 1 1 <1 1 1 h a p p e n d i x h-24 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans da + code 1132 680 7489 7490 7491 31073 31087 1135 32886 32887 29724 29725 508 1137 32940 1138 517 1166 1139 1140 518 32889 32931 32896 1153 520 1152 32895 32911 32922 32923 4958 32904 32901 32902 1156 1157 32905 32932 1159 32933 32906 2807 2806 1763 2804 1884 30303 30305 524 h x i d n e p p a vegetables, legumes continued vegetables, mixed canned, drained frozen, boiled, drained vegetable juice, v8 100% vegetable juice, v8 low sodium vegetable juice, v8 spicy hot water chestnuts sliced, drained whole watercress nuts, seeds, and products almonds blanched dry roasted, no salt added dry roasted, salted oil roasted, salted slivered almond butter, no salt added almond butter, salt added beechnuts, dried brazil nuts, unblanched, dried breadfruit seeds, roasted butternuts, dried cashews dry roasted oil roasted cashew butter, no salt added cashew butter, salt added coconut dried, not sweetened dried, shredded, sweetened shredded chestnuts chinese, roasted european, boiled & steamed european, roasted japanese, boiled & steamed japanese, roasted flaxseeds or linseeds ginkgo nuts, dried hazelnuts or lberts blanched dry roasted, no salt added hickorynuts, dried macadamias raw dry roasted, no salt added dry roasted, salt added mixed nuts with peanuts, dry roasted with peanuts, dry roasted, salt added without peanuts, oil roasted, no salt added peanuts dry roasted dry roasted, salted oil roasted, salted raw peanut butter, chunky peanut butter, low sodium peanut butter, reduced fat peanut butter, smooth pecans 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 1 4 1 4 1 4 1 4 1 4 1 1 1 4 1 4 1 4 1 4 1 4 1 4 1 1 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 1 1 1 1 4 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) 82 91 120 120 120 75 75 34 71 76 113 113 113 70 70 32 cup(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) cup(s) 36 35 35 39 34 16 16 57 35 57 30 34 33 16 16 60 24 21 57 57 57 57 57 57 57 57 57 30 34 34 34 34 34 36 37 37 36 37 16 16 18 16 57 2 1 1 1 2 <1 <1 4 1 28 1 1 1 <1 <1 2 3 10 23 39 23 49 28 5 7 3 1 1 <1 1 1 1 1 1 0 0 0 2 <1 <1 <1 <1 1 40 59 25 25 25 20 20 4 211 206 206 238 195 101 101 327 230 118 184 197 189 94 94 393 122 75 136 74 139 32 114 276 197 357 366 197 241 241 240 203 203 221 214 214 216 207 94 95 94 96 403 2 3 1 0 1 <1 <1 1 8 8 8 8 7 2 2 4 5 4 7 5 5 3 3 4 1 1 3 1 2 <1 2 11 6 8 9 4 3 3 3 6 6 6 9 9 10 9 4 4 5 4 5 8 12 5 7 5 5 5 <1 7 7 7 7 7 3 3 19 4 23 4 11 10 4 4 14 12 3 30 16 30 7 26 19 41 10 10 5 5 4 4 9 9 8 8 8 5 6 3 3 6 3 8 2 4 1 1 1 1 1 <1 4 4 4 4 4 1 1 5 3 3 1 1 1 <1 <1 10 1 2 0 0 3 0 0 16 0 6 5 2 3 3 3 3 3 2 3 3 3 3 1 1 1 1 5 <1 <1 0 0 0 0 0 <.1 18 18 18 22 17 9 9 28 23 2 17 16 16 8 8 38 9 7 1 1 1 <1 <1 19 1 35 35 19 25 25 25 18 18 20 18 18 19 18 8 8 6 8 42 0.04 0.03 0.00 0.00 0.00 0.00 0.00 0.01 1.41 1.40 1.40 1.65 1.31 0.90 0.90 3.25 5.30 0.41 0.39 3.14 2.76 1.56 1.56 34.06 7.68 6.27 0.10 0.15 0.23 0.02 0.07 1.79 0.22 2.65 2.56 2.11 4.04 4.00 4.00 2.36 2.36 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 11.70 11.61 11.61 13.66 10.85 6.14 6.14 12.43 8.59 0.20 3.13 9.36 8.42 4.66 4.66 1.63 0.37 0.30 0.35 0.27 0.43 0.06 0.24 3.85 0.42 27.32 26.43 9.78 19.72 19.86 19.86 10.75 10.75 0.10 0.07 0.00 0.00 0.00 0.00 0.00 0.01 0 0 0 0 0 4.37 4.36 4.36 5.31 4.12 1.98 1.98 11.41 7.20 0.82 12.82 2.68 2.78 1.34 1.34 0.42 0.09 0.08 0.17 0.31 0.49 0.03 0.12 12.54 0.42 3.15 4.80 6.57 0.50 0.50 0.50 3.69 3.69 3.27 11.93 4.12 2.51 2.51 3.12 2.49 1.53 1.66 1.33 1.60 8.99 8.99 9.33 8.92 3.77 3.88 2.91 3.96 5.72 5.72 5.49 5.68 2.27 2.21 1.85 2.38 32907 dry roasted, no salt added 3.56 24.92 11.66 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-25 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 22 23 20 20 20 7 7 41 78 92 92 114 84 43 43 1 56 49 16 15 14 7 7 15 4 3 11 26 16 6 20 111 11 84 70 18 28 23 23 24 24 38 20 20 22 34 8 6 6 8 41 0.86 0.75 0.54 0.36 0.36 0.23 0.23 0.07 1.35 1.56 1.56 1.44 1.45 0.59 0.59 1.40 0.85 0.51 1.21 2.06 1.97 0.80 0.80 1.98 0.47 0.51 0.85 0.98 0.52 0.30 1.19 3.48 0.91 1.87 2.48 0.64 1.24 0.89 0.89 1.27 1.27 0.93 0.82 0.82 0.54 1.67 0.33 0.29 0.34 0.30 1.59 13 20 13 13 7 100 99 99 108 93 48 48 0 132 35 71 89 89 41 41 54 12 7 51 31 19 10 36 203 30 91 98 52 44 40 40 77 77 90 64 64 63 61 31 25 31 28 75 237 154 270 420 255 112 249 257 257 274 246 121 121 578 231 615 126 194 205 87 87 323 82 75 271 405 336 67 242 381 566 373 428 131 123 122 122 204 204 196 240 240 261 257 101 107 120 88 121 32 310 70 370 6 6 14 10 <1 117 133 <1 2 72 22 1 16 <1 5 4 2 98 22 64 4 2 15 1 3 11 19 7 0 0 <1 2 1 89 4 229 4 2 297 115 7 75 3 97 80 0.33 0.45 0.24 0.24 0.04 1.13 1.22 1.22 1.20 1.13 0.49 0.49 0.20 1.42 0.59 0.94 1.92 1.74 0.83 0.83 1.20 0.44 0.23 0.53 0.14 0.32 0.23 0.81 2.34 0.38 1.25 1.42 1.29 0.44 0.43 0.43 1.30 1.30 1.68 1.20 1.20 1.18 1.19 0.52 0.47 0.50 0.47 240 1 2.87 474 195 50 63 50 0 0 80 0 0 0 0 0 0 0 0 0 9 2 0 0 0 0 0 0 0 0 1 1 1 2 0 31 1 2 2 0 0 0 <1 0 <1 0 0 0 0 0 0 0 0 4 0.04 0.06 0.05 0.02 0.05 0.03 0.07 0.03 0.03 0.04 0.08 0.02 0.02 0.17 0.22 0.23 0.11 0.07 0.12 0.05 0.05 0.04 0.01 0.01 0.09 0.08 0.14 0.07 0.26 0.10 0.24 0.27 0.19 0.26 0.40 0.24 0.24 0.07 0.07 0.18 0.15 0.15 0.03 0.23 0.02 0.01 0.05 0.01 0.28 0.40 0.34 8.96 8.97 8.97 10.19 8.73 2.01 0.32 0.30 0.15 0.26 0.10 0.05 0.28 9.92 8.66 0.18 0.19 0.19 3.75 0.04 0.11 0.03 0.02 0.03 0.04 0.20 0.30 0.30 0.31 0.27 0.10 0.10 0.21 0.01 0.14 0.04 0.07 0.07 0.03 0.03 0.06 0.00 0.00 0.05 0.06 0.10 0.03 0.09 0.10 0.06 0.07 0.04 0.05 0.03 0.03 0.07 0.07 0.47 0.77 0.87 0.75 0.88 0.07 1.33 1.33 1.33 1.44 1.32 0.46 0.46 0.50 0.10 4.20 0.31 0.48 0.56 0.26 0.26 0.36 0.12 0.11 0.85 0.41 0.76 0.31 0.40 0.78 6.65 0.88 1.16 0.27 0.83 0.76 0.76 1.61 1.61 0.06 0.07 0.17 0.17 0.04 0.04 0.04 0.04 0.05 0.04 0.01 0.01 0.39 0.04 0.24 0.17 0.09 0.10 0.04 0.04 0.18 0.07 0.01 0.25 0.13 0.28 0.06 0.24 0.52 0.36 0.33 0.35 0.06 0.09 0.12 0.12 0.10 0.10 0.17 0.71 0.06 2.56 2.89 2.50 3.04 1.01 1.23 1.20 1.44 0.03 0.03 0.03 0.05 0.02 0.02 0.01 0.02 4.93 4.93 4.97 4.40 2.19 2.14 2.63 2.14 0.09 0.09 0.16 0.13 0.07 0.07 0.06 0.07 0.26 0.74 0.06 0.66 0.11 20 17 3 11 11 11 11 10 10 10 64 8 34 20 24 8 11 11 5 2 5 41 22 40 10 33 156 60 44 50 12 4 3 3 17 17 20 53 53 43 88 15 12 11 12 9 4 3 30 30 18 2 2 15 0 0 0 0 0 <1 <1 9 <1 4 1 0 <.1 0 0 1 <1 1 22 15 15 5 16 1 17 1 2 1 <1 <1 <1 <1 <1 <1 0 0 <1 0 0 0 0 0 <1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <1 <1 1 1 1 1 1 1 4 671 8 5 4 7 2 2 11 4 2 4 1 3 2 2 2 1 1 4 1 3 3 3 1 3 1 1 2 h a p p e n d i x h-26 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 32936 1162 526 12973 1164 32938 1167 1169 32912 32941 34173 34174 528 29721 29723 32928 4646 4647 4648 529 531 34222 34368 34247 34261 34397 34238 34308 34276 34243 34454 34339 34356 34311 34371 34282 34367 32067 32070 32069 32074 32075 32073 32072 32071 32068 32066 37810 39661 39666 37808 39665 37805 39663 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans nuts, seeds, and products continued dry roasted, salt added halves, oil roasted raw pine nuts or pignolia, dried pistachios dry roasted dry roasted, salt added pumpkin or squash seeds, roasted sesame sesame seeds, whole, roasted, toasted sesame butter paste tahini or sesame butter soy nuts deep sea salted unsalted sun ower seeds kernels, dried kernels, dry roasted, salted kernels, toasted, salted sun ower seed butter, salt added trail mix trail mix trail mix with chocolate chips tropical trail mix walnuts dried black, chopped english or persian vegetarian foods prepared brown rice & tofu stir-fry (vegan) cheese enchilada casserole (lacto) five bean casserole (vegan) lentil stew (vegan) macaroni & cheese (lacto) steamed rice & vegetables (vegan) tofu rice burgers (ovo-lacto) vegan spinach enchiladas (vegan) vegetable chow mein (vegan) vegetable lasagna (lacto) vegetable marinara (vegan) vegetable rice casserole (lacto) vegetable strudel (ovo-lacto) vegetable taco (lacto) vegetarian chili (vegan) vegetarian vegetable soup (vegan) boca burger all american amed grilled patty bigger chef max s favorite bigger vegan boca chik n nuggets boca meatless ground burger boca tenders breakfast links breakfast patties roasted garlic patty vegan original patty gardenburger bbq chik n with sauce black bean burger buffalo chick n wing chik n grill country fried chicken w/creamy pepper gravy crispy nuggets homestyle classic burger 1 4 1 4 1 4 1 1 4 1 4 1 4 3 1 1 1 4 1 4 1 4 1 4 1 4 1 1 4 1 4 1 4 1 4 1 4 8 8 8 8 8 8 1 1 8 8 8 8 8 1 8 8 1 1 1 4 1 2 1 2 1 1 1 1 1 3 1 1 6 1 cup(s) cup(s) cup(s) tablespoon(s) cup(s) cup(s) cup(s) teaspoon(s) tablespoon(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) piece(s) piece(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) item(s) ounce(s) ounce(s) item(s) item(s) item(s) item(s) cup(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 57 28 27 9 32 32 57 9 16 15 56 56 36 32 34 16 38 38 35 31 30 227 227 228 228 226 228 218 82 227 225 229 227 227 227 227 226 71 99 99 87 57 85 45 38 71 71 1 <1 1 <1 1 1 4 <1 <1 <1 2 <1 <1 <1 3 2 3 1 1 183 86 178 152 163 100 78 59 163 154 182 172 100 147 196 204 142 71 95 71 142 82 71 403 197 187 58 183 182 296 51 95 89 240 240 205 186 207 93 173 182 142 193 196 228 410 178 125 181 265 435 93 166 177 94 230 756 365 116 92 110 130 120 190 70 140 100 80 100 90 250 80 180 100 190 180 110 5 3 2 1 7 7 19 2 3 3 24 24 8 6 6 3 5 5 2 8 5 12 18 6 8 8 5 22 5 6 12 3 9 19 13 6 3 14 18 18 16 11 20 10 8 14 13 14 8 9 13 9 4 12 8 4 4 1 9 9 8 2 4 3 18 18 7 8 7 4 17 17 23 3 4 13 41 26 24 17 40 68 15 22 25 15 24 51 43 21 14 6 11 11 16 7 9 6 5 7 4 30 11 8 5 16 22 6 5 3 3 <1 3 3 2 1 1 1 10 10 4 3 4 0 2 0 0 2 2 3 4 5 7 <1 3 6 2 2 2 1 4 4 9 7 2 4 5 6 2 4 3 5 3 5 0 5 4 5 3 2 3 4 42 21 19 6 15 15 24 4 8 8 8 8 18 16 19 8 11 12 6 18 20 16 19 6 <1 9 10 8 2 6 4 3 12 54 17 2 4 4 4 0 7 1 3 4 4 2 1 8 2 12 3 9 9 5 3.56 1.99 1.67 0.42 1.78 1.78 4.52 0.60 1.14 1.11 2.00 2.00 1.87 1.67 1.99 0.80 2.08 2.29 2.97 1.05 1.84 1.25 10.06 1.11 0.08 4.37 1.84 1.69 0.34 0.65 1.92 0.36 4.67 18.24 6.45 0.24 0.77 1.00 1.00 0.00 2.00 0.00 0.00 0.00 0.00 0.50 0.00 1.00 0.00 1.50 0.00 1.00 1.50 0.50 24.92 11.27 11.02 1.61 11.66 6.49 5.84 2.93 7.75 7.75 7.43 1.63 3.07 3.00 3.41 3.04 3.63 1.46 4.70 5.08 0.87 4.69 2.68 4.03 6.54 2.49 0.07 2.88 3.91 2.39 0.55 2.66 0.93 1.32 3.48 26.38 5.81 0.29 1.67 1.00 0.00 2.00 4.45 4.45 10.90 1.89 3.57 3.48 11.78 10.52 12.56 5.04 3.62 4.23 1.81 10.96 14.15 9.54 1.24 1.96 0.21 0.89 4.07 3.52 1.27 2.47 0.34 0.92 2.96 6.17 4.02 0.74 1.30 1.50 0.00 1.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-27 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 42 0 0 22 0 51 0 0 10 0 16 46 21 <1 0 3 5 0 0 0 0 0 0 3 0 0 0 0 0 5 5 0 41 18 19 1 35 35 24 89 154 21 120 120 42 22 19 20 29 41 20 19 29 266 468 48 23 187 41 468 117 190 144 15 176 318 231 68 37 150 150 60 80 80 80 60 60 100 80 150 40 40 60 40 60 80 1.59 0.68 0.68 0.48 1.34 1.34 8.48 1.33 3.07 0.66 2.16 2.16 2.44 1.22 2.28 0.76 1.14 1.27 0.92 0.98 0.87 4.73 2.58 1.71 2.35 0.77 1.43 4.78 1.13 3.65 1.91 0.85 1.72 3.36 2.58 2.42 1.32 1.80 2.70 1.80 1.80 1.44 1.08 1.44 1.44 1.80 1.80 1.08 1.44 0.72 3.60 1.44 0.72 1.44 75 33 33 22 <1 38 38 303 32 58 14 127 41 43 59 59 60 34 63 47 88 37 42 31 20 68 90 40 28 33 17 28 39 83 41 28 240 108 111 51 333 333 457 43 93 69 248 272 164 12 257 243 248 163 132 375 204 367 380 120 358 455 168 302 393 180 395 299 550 532 443 220 217 <1 0 <1 <1 <1 10 1 2 5 300 20 1 250 205 83 86 45 4 1 1 112 1219 618 289 768 1403 2454 134 371 637 378 609 813 893 383 503 370 400 380 570 220 440 330 260 400 350 890 330 1000 360 550 570 380 2.87 1.23 1.22 0.55 0.74 0.74 4.22 0.64 1.17 0.69 1.82 1.69 1.78 0.85 1.21 1.18 0.41 1.05 0.93 1.51 1.96 0.60 0.87 1.11 0.91 2.07 0.68 0.74 1.06 0.35 1.19 1.98 1.80 0.78 0.44 4 1 1 <.1 4 4 11 0 <1 <1 0 0 1 <1 0 <1 <1 1 1 1 <1 121 107 54 18 82 86 82 26 8 31 18 121 288 81 46 109 0 0 0 0 0 0 0 0 0 0.26 0.13 0.18 0.03 0.27 0.27 0.12 0.07 0.04 0.24 0.82 0.03 0.11 0.05 0.17 0.15 0.16 0.02 0.10 0.14 0.33 0.09 0.14 0.15 0.16 0.27 0.07 0.13 0.20 0.13 0.16 0.45 0.23 0.13 0.11 0.74 0.70 0.38 0.80 0.62 0.62 0.00 12.42 8.35 0.56 0.21 0.07 0.06 0.53 0.14 0.29 3.05 0.12 0.06 0.05 0.50 0.35 0.21 0.10 0.15 0.55 0.06 0.03 0.04 0.02 0.05 0.05 0.18 0.02 0.03 0.02 0.09 0.08 0.10 0.05 0.07 0.08 0.04 0.04 0.05 0.12 0.38 0.08 0.10 0.24 0.12 0.27 0.07 0.12 0.27 0.08 0.29 0.50 0.18 0.13 0.08 0.66 0.33 0.32 0.38 0.46 0.46 0.99 0.41 1.07 0.85 1.62 2.25 1.41 0.85 1.77 1.65 0.52 0.15 0.34 1.08 2.38 0.93 1.50 1.02 2.76 3.43 0.54 1.43 2.07 1.25 1.93 4.52 1.48 1.26 1.54 0.11 0.05 0.06 0.01 0.41 0.41 0.05 0.07 0.13 0.02 0.28 0.26 0.27 0.13 0.11 0.10 0.11 0.18 0.16 0.28 0.11 0.11 0.16 0.04 0.30 0.30 0.11 0.15 0.21 0.11 0.18 0.16 0.25 0.18 0.22 9 4 6 6 16 16 32 9 16 15 82 76 80 38 27 24 15 10 29 32 77 33 61 39 28 99 46 47 64 41 92 123 132 58 38 <1 <1 <1 <.1 1 1 1 0 0 1 0 0 1 <1 <1 <1 1 <1 3 1 <1 18 22 8 13 <.1 13 2 1 7 15 20 54 27 12 16 24 0 0 2 0 0 0 0 0 1 1 0 0 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <.1 0 <1 <.1 <1 0 0 <1 0 <1 <1 <1 0 <.1 2 2 1 <.1 3 3 3 1 1 <1 21 25 21 5 1 11 22 4 9 16 8 43 5 6 19 10 6 31 10 5 1 h a p p e n d i x h-28 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 37807 37809 37806 29913 31707 29915 9311 9315 9317 9323 9326 9336 9354 33707 9362 9368 9371 33705 11587 2531 9412 33702 9422 9424 9432 9440 9442 9478 9480 9462 9486 9496 9434 1433 884 885 34821 888 32096 5 889 890 891 8527 893 894 895 896 13 12 897 898 14 17 19 18 20 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans vegetarian foods continued meatless breakfast sausage meatless meatballs meatless riblets w/sauce original santa fe veggie medley loma linda big franks chik n nuggets corn dogs fried chik n with gravy linketts, canned redi-burger patties, canned tender rounds meatball substitute, canned in gravy morningstar farms america s original veggie dog links better n eggs egg substitute breakfast links breakfast strips chik nuggets chik patties garden veggie patties natural touch low fat vegetarian chili, canned spicy black bean veggie burger worthington chik stiks chili, canned crispychik patties dinner roast, frozen fillets, frozen meatless smoked beef, sliced meatless smoked turkey, sliced prosage links stripples bacon substitute vegetable skallops vegetarian cutlets dairy butter: see fats & oils cheese blue, crumbled brick brie camembert cheddar or colby cheddar or colby, low fat cheddar, shredded edam feta fontina goat, soft gouda gruyere limburger monterey jack mozzarella, part skim milk mozzarella, whole milk muenster neufchatel parmesan, grated provolone ricotta, part skim milk ricotta, whole milk romano 1 6 1 3 3 3 1 5 1 2 1 1 6 1 1 4 2 2 4 1 1 1 1 1 1 1 1 2 6 3 2 2 1 2 1 1 1 1 1 1 1 1 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1 4 1 item(s) item(s) item(s) ounce(s) ounce(s) ounce(s) item(s) item(s) item(s) piece(s) item(s) slice(s) piece(s) item(s) cup(s) item(s) item(s) piece(s) item(s) item(s) cup(s) item(s) item(s) cup(s) item(s) slice(s) piece(s) slice(s) slice(s) item(s) item(s) cup(s) slice(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) cup(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) tablespoon(s) ounce(s) cup(s) cup(s) tablespoon(s) 43 85 142 85 85 85 51 85 71 80 35 85 80 57 57 45 16 86 71 67 230 78 47 230 71 85 85 57 57 45 16 85 61 28 28 28 29 28 28 28 28 28 28 28 28 28 28 28 28 28 28 28 5 28 62 62 5 30 40 31 46 21 50 54 50 27 7 36 40 173 47 27 167 37 53 48 27 7 65 43 12 12 14 15 11 18 10 12 15 11 17 12 9 14 11 15 14 12 17 1 11 46 44 2 50 110 210 132 156 108 110 240 150 150 70 120 120 80 20 80 60 180 150 100 170 150 110 290 150 180 180 130 140 80 60 90 70 100 104 94 87 110 49 114 100 74 109 76 100 116 92 104 71 84 103 73 22 98 85 107 19 5 12 17 7 6 10 14 7 12 7 18 13 11 5 9 2 13 9 10 18 11 10 19 9 12 16 11 10 9 2 15 11 6 7 6 6 7 7 7 7 4 7 5 7 8 6 7 7 6 7 3 2 7 7 7 2 2 8 11 19 24 22 2 13 22 5 1 7 6 6 0 3 2 17 16 9 21 16 4 21 16 5 8 7 5 3 2 3 3 1 1 <1 <1 1 1 <1 <1 1 <1 <1 1 <1 <1 <1 1 1 <1 1 <1 1 3 2 <1 2 4 4 4 5 4 2 4 3 2 1 4 1 1 0 2 1 5 2 4 11 5 2 9 2 3 4 1 0 2 1 3 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 5 5 4 3 0 7 15 4 10 5 3 5 1 0 3 5 6 6 3 1 5 6 15 6 12 9 7 9 3 5 2 1 8 8 8 7 9 2 9 8 6 9 6 8 9 8 8 4 6 8 7 1 7 5 8 1 0.00 1.00 0.00 1.80 1.20 0.00 1.00 2.00 0.50 1.50 0.50 0.50 1.80 0.00 2.00 4.50 1.00 2.50 1.00 0.50 0.60 0.00 4.00 8.00 2.50 5.00 2.50 1.50 0.50 1.00 2.50 0.00 0.00 0.50 0.50 0.50 1.00 0.50 0.50 1.00 2.50 1.00 1.50 1.00 1.00 1.00 0.50 0.50 0.50 5.29 5.25 4.87 4.43 5.66 1.23 5.96 4.92 4.18 5.37 4.14 4.93 5.30 4.69 5.34 2.83 3.68 5.35 4.14 0.87 4.78 3.03 5.10 0.86 0.00 0.00 0.50 1.00 1.50 1.50 0.50 1.50 1.00 3.50 1.50 5.00 3.50 2.00 2.50 0.50 1.00 0.50 2.21 2.41 2.24 2.04 2.60 0.59 2.65 2.28 1.29 2.43 1.37 2.17 2.81 2.41 2.45 1.26 1.84 2.44 1.90 0.42 2.07 1.42 2.23 0.39 0.00 0.00 2.00 3.00 4.00 2.50 1.50 2.50 3.00 9.00 3.50 5.00 4.50 4.00 5.00 2.00 2.50 0.00 0.23 0.22 0.23 0.21 0.27 0.06 0.27 0.19 0.17 0.46 0.14 0.18 0.49 0.14 0.25 0.13 0.21 0.19 0.18 0.06 0.22 0.16 0.24 0.03 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-29 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 24 24 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 21 26 28 21 27 6 30 25 25 32 13 32 31 25 25 18 22 27 21 4 19 19 31 5 20 60 60 72 96 48 0 20 0 20 0 0 20 0 20 0 0 40 0 40 40 40 20 40 0 40 0 20 100 0 0 0 0 150 189 52 112 192 118 204 205 138 154 40 196 283 139 209 219 141 201 21 55 212 167 127 53 0.72 1.80 1.80 0.00 0.00 0.00 0.77 1.44 1.08 1.80 0.36 1.06 1.08 0.72 0.63 1.44 0.27 3.60 1.80 0.72 1.80 1.80 1.80 3.60 1.80 0.36 1.80 1.80 2.70 1.44 0.36 0.72 0.00 0.09 0.12 0.14 0.10 0.21 0.12 0.19 0.12 0.18 0.06 0.54 0.07 0.05 0.04 0.20 0.06 0.12 0.11 0.08 0.05 0.15 0.27 0.23 0.04 37 32 44 7 7 6 6 7 5 8 8 5 4 5 8 10 6 8 6 6 8 2 2 8 9 7 2 232 218 50 210 60 70 15 140 80 60 75 50 15 330 210 180 480 320 100 420 170 55 130 180 60 50 15 10 30 73 38 43 54 36 19 28 53 17 18 7 34 23 36 23 24 21 38 32 6 39 77 65 4 120 400 720 672 336 336 240 410 500 430 160 450 340 580 90 320 220 590 540 350 870 470 300 1130 440 580 750 510 490 320 220 410 340 395 157 176 244 169 174 175 270 312 224 105 229 94 224 150 173 176 176 112 76 245 77 52 60 1.07 0.55 0.89 0.43 0.43 0.34 0.46 1.11 0.66 0.60 0.36 0.05 0.31 0.58 1.36 0.93 0.31 1.24 0.33 0.64 0.92 0.14 0.23 0.36 0.05 0.67 0.43 0.75 0.73 0.67 0.69 0.86 0.52 0.88 1.05 0.81 0.98 0.26 1.09 1.09 0.59 0.84 0.77 0.82 0.79 0.15 0.19 0.90 0.82 0.71 0.13 0 0 0 0 0 0 0 0 0 0 75 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 82 49 74 17 75 68 35 73 82 46 76 95 55 36 50 83 83 6 66 66 74 5 0.12 0.08 0.23 0.75 0.72 1.05 0.12 0.23 0.75 0.03 1.80 0.75 1.20 1.80 6.47 0.60 0.60 0.06 1.80 1.80 0.68 1.80 1.80 1.80 0.75 0.03 0.03 0.01 0.00 0.02 0.01 0.00 0.00 0.01 0.01 0.04 0.01 0.02 0.01 0.02 0.02 0.00 0.01 0.01 0.00 0.00 0.00 0.01 0.01 0.01 0.00 0.07 0.07 0.07 0.08 0.02 0.08 0.07 0.05 0.08 0.05 0.07 0.08 0.06 0.07 0.04 0.05 0.07 0.01 0.06 0.04 0.07 0.01 0.18 0.10 0.43 0.51 0.61 0.34 0.20 0.34 1.30 1.08 1.60 6.00 1.47 4.00 0.40 6.00 0.10 0.11 0.04 0.90 0.87 0.30 0.20 0.40 0.17 2.00 0.16 0.34 0.17 0.04 0.26 0.17 0.10 0.21 0.14 0.17 0.07 0.17 0.26 0.14 0.17 0.17 0.17 0.03 0.03 0.04 0.11 0.10 0.15 0.14 0.11 0.06 0.11 0.11 0.24 0.06 0.11 0.09 0.08 0.14 0.11 0.08 0.08 0.09 0.05 0.02 0.09 0.11 0.12 0.02 0.00 2.00 0.40 5.00 2.00 0.00 0.00 0.00 6.00 2.00 2.00 6.00 0.80 6.00 6.00 2.00 0.40 0.00 0.00 0.29 0.03 0.11 0.18 0.03 0.01 0.02 0.02 0.28 0.04 0.12 0.02 0.03 0.04 0.03 0.03 0.03 0.03 0.04 0.01 0.04 0.05 0.06 0.00 0.08 0.30 0.07 0.40 0.20 0.00 0.30 0.21 0.40 0.70 0.20 0.60 0.40 0.40 0.40 0.30 0.08 0.01 0.04 0.05 0.02 0.07 0.07 0.02 0.01 0.02 0.02 0.12 0.02 0.07 0.02 0.02 0.02 0.02 0.02 0.01 0.02 0.01 0.00 0.02 0.01 0.03 0.00 12 13 24 10 6 18 18 5 3 5 4 9 2 3 6 3 16 5 3 2 3 3 1 3 8 7 <1 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <.1 1 3 2 2 1 2 1 1 3 <1 3 1 0 0 <.1 2 2 1 2 3 2 3 3 <1 0 0 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <.1 <1 <1 <1 <1 <1 1 <1 <.1 <1 <1 <1 <1 <.1 8 0 5 4 4 4 4 4 4 4 4 4 4 1 4 4 4 4 4 5 4 1 1 4 10 9 1 h a p p e n d i x h-30 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 900 21 7998 8028 9 8 11 17366 10438 22 24 25 9110 23 10430 10435 26 28 30 32 34 36 30556 3659 40 35972 35975 35976 904 57 58 54 55 60 51 52 50 61 62 63 64 65 5234 907 909 69 68 67 33156 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans dairy continued roquefort swiss imitation cheese shredded imitation cheddar shredded imitation mozzarella cottage cheese low fat, 1% fat low fat, 2% fat cream cheese cream cheese fat free cream cheese tofutti better than cream cheese processed cheese american cheese, processed american cheese food, processed american cheese spread, processed kraft deluxe singles pasteurized process american cheese swiss cheese, processed soy cheese nu tofu cheddar avored cheese alternative nu tofu mozzarella avored cheese alternative cream half & half light coffee or table, liquid light whipping cream, liquid heavy whipping cream, liquid whipped cream topping, pressurized sour cream sour cream fat free sour cream imitation cream coffeemate nondairy creamer, liquid cream substitute, powder nondairy coffee whitener, liquid, frozen nondairy dessert topping, pressurized nondairy dessert topping, frozen imitation sour cream fluid milk fat free, nonfat, or skim fat free, nonfat, or skim, w/nonfat milk solids low fat, 1% low fat, 1%, w/nonfat milk solids low fat buttermilk reduced fat, 2% reduced fat, 2%, w/nonfat milk solids whole, 3.3% canned whole evaporated fat free, nonfat, or skim evaporated sweetened condensed dried milk dried buttermilk instant nonfat dry milk w/added vitamin a skim milk powder whole dry milk goat milk chocolate milk low fat reduced fat whole milk chocolate syrup, forti ed, prepared w/milk 1 1 1 4 1 4 1 2 1 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 1 1 1 1 2 1 1 1 1 1 1 1 1 2 2 2 1 4 1 4 1 4 1 4 1 1 1 1 1 ounce(s) ounce(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) tablespoon(s) tablespoon(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) teaspoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) tablespoon(s) tablespoon(s) tablespoon(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) 28 28 28 28 113 113 29 30 30 28 28 28 28 28 28 28 15 15 15 15 4 24 32 16 2 16 5 5 24 11 10 93 90 16 23 11 12 14 12 12 11 10 9 2 17 26 <.1 12 3 3 17 245 223 245 244 245 245 244 245 244 32 32 38 30 17 18 32 244 250 250 250 221 219 220 221 218 218 216 23 25 10 1 1 1 1 212 211 209 206 103 106 90 80 81 102 101 29 80 106 94 82 110 95 70 70 20 29 44 52 10 51 24 20 11 22 12 16 50 83 91 102 105 98 122 125 146 42 25 123 6 8 5 6 14 16 2 4 1 6 5 5 5 7 6 6 <1 <1 <1 <1 <1 1 1 0 <.1 <1 <.1 <.1 1 8 9 8 9 8 8 9 8 2 2 3 118 10 63 64 161 168 158 180 208 6 6 9 9 8 8 8 8 1 2 2 1 3 4 1 2 1 <1 2 2 1 1 1 2 1 1 <1 <1 <1 1 5 2 1 2 1 1 2 12 12 12 12 12 11 12 11 3 4 21 15 9 9 12 11 26 26 26 24 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 2 <1 9 8 7 6 1 2 10 <1 8 9 7 6 9 7 4 4 2 3 5 6 1 5 0 1 1 2 1 1 5 5.39 4.98 1.50 1.00 0.73 1.38 6.37 0.27 2.00 5.58 4.23 3.78 6.00 4.55 2.37 2.04 0.37 0.27 0.33 0.62 2.85 0.10 2.54 2.05 1.77 2.00 0.04 0.07 0.37 0.02 6.00 0.28 0.31 0.18 0.18 0.50 2.50 1.00 0.50 2.50 1.00 1.07 1.80 2.90 3.45 0.52 3.13 0.00 0.00 0.65 0.31 0.88 1.09 4.27 0.50 0.84 1.36 1.60 0.24 1.45 0.00 0.50 0.02 1.20 0.09 0.08 0.14 0.06 0.11 0.13 0.21 0.03 0.19 0.00 0.00 0.00 0.00 0.01 0.03 0.01 <1 0.29 0.12 0.02 1 2 2 2 5 5 8 2 <.1 3 2 <1 <1 9 10 3 5 8 8 0.40 1.54 1.48 1.34 2.35 2.93 4.55 1.45 0.04 2.10 0.16 0.68 0.69 0.62 2.04 1.36 1.98 0.74 0.02 0.93 0.02 0.09 0.09 0.08 0.17 0.17 0.48 0.08 0.00 0.13 1.09 0.51 0.07 0.08 0.08 5.43 6.51 1.54 3.10 5.26 0.03 0.03 2.57 2.71 0.75 1.47 2.48 0.00 0.01 0.22 0.36 0.09 0.18 0.31 5.22 2.44 0.31 0 263 220 197 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-31 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 25 26 0 0 5 9 32 2 0 27 23 16 25 24 0 0 6 10 17 21 3 11 3 0 0 0 0 0 0 5 5 12 10 10 20 20 24 9 1 13 21 3 3 31 27 8 18 30 34 185 221 150 150 69 78 23 56 0 156 162 160 150 219 200 150 16 14 10 10 4 28 40 0 <1 1 <1 <1 1 223 316 264 314 284 271 314 246 82 93 109 360 215 222 296 327 288 285 280 292 0.16 0.06 0.00 0.00 0.16 0.18 0.35 0.05 0.00 0.05 0.16 0.09 0.00 0.17 0.36 0.36 0.01 0.01 0.00 0.00 0.00 0.01 0.00 0.00 0.02 0.00 0.00 0.01 0.09 1.23 0.12 0.85 0.12 0.12 0.24 0.12 0.07 0.06 0.09 0.07 0.09 0.05 0.06 0.15 0.12 0.60 0.60 0.60 2.68 8 11 8 6 7 2 4 8 9 8 0 8 2 1 1 1 <1 3 3 <.1 <.1 <.1 <.1 1 22 37 27 34 27 27 34 24 8 9 10 33 20 21 28 34 33 33 33 32 25 22 97 108 35 49 48 83 69 25 61 20 18 15 11 6 35 41 30 16 30 1 1 39 507 54 420 320 459 459 86 164 135 422 359 382 450 388 190 190 6 6 5 6 5 13 45 0 4 13 3 1 24 0.58 1.22 1.20 0.43 0.47 0.16 0.26 0.81 0.91 0.74 0.90 1.02 0.08 0.04 0.04 0.03 0.01 0.06 0.16 0.01 0.00 0.00 0.00 0.28 82 62 12 24 106 84 0 72 57 49 84 56 15 27 42 62 7 42 0 <.1 0 0.01 0.02 0.00 0.02 0.03 0.00 0.02 0.01 0.02 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.00 0.00 0.00 0.00 0.00 0.11 0.01 0.02 0.09 0.00 0.08 0.06 0.05 0.10 0.05 0.08 0.13 0.16 0.02 0.14 0.00 0.01 0.18 0.16 0.08 0.26 0.19 0.21 0.06 0.05 0.10 0.15 0.12 0.10 0.08 0.02 0.02 0.02 0.02 0.00 0.04 0.05 0.02 0.00 0.00 0.00 0.00 0.00 0.21 0.03 0.00 0.14 0.16 0.03 0.05 0.02 0.05 0.04 0.01 0.01 0.01 0.01 0.01 0.00 0.02 0.02 0.20 0.00 0.00 0.00 0.00 0.00 0.03 0.02 0.00 0.08 0.09 0.01 0.02 0.02 0.02 0.03 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 238 108 2.08 149 0.11 0.02 0.45 0.23 0.09 419 290 397 370 342 397 325 95 106 142 130 122 127 257 115 127 105 33 37 49 1.00 2.12 0.98 1.03 1.17 0.98 0.93 0.24 0.29 0.36 484 157 1.22 298 307 431 498 425 423 418 96 99 120 122 153 150 150 0.77 0.79 1.08 0.73 1.03 1.03 1.03 149 142 145 17 134 137 68 20 38 28 15 124 0 83 139 145 138 65 460 147 0.92 0.10 0.05 0.10 0.08 0.10 0.10 0.11 0.01 0.01 0.03 0.00 0.02 0.12 0.07 0.15 0.04 0.00 0.06 0.43 0.45 0.42 0.38 0.45 0.42 0.45 0.10 0.10 0.16 0.22 0.23 0.22 0.14 0.22 0.22 0.26 0.06 0.06 0.08 0.11 0.09 0.11 0.08 0.09 0.11 0.09 0.02 0.02 0.02 0.12 0.03 0.48 0.27 0.10 0.07 0.07 0.09 0.12 0.10 0.09 0.09 0.09 0.00 0.16 0.17 0.05 0.10 0.15 0.30 0.31 0.39 0.34 0.42 0.41 0.41 0.16 0.16 0.21 0.68 0.32 0.32 0.31 0.06 0.06 0.10 0.11 0.10 0.10 0.10 0.55 6.53 0.11 14 2 40 14 15 4 11 2 2 2 2 <1 <1 1 1 <1 3 4 0 0 0 0 0 12 12 12 12 12 12 12 12 3 3 4 14 9 9 12 2 13 13 13 13 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <1 <.1 <.1 0 <1 0 0 0 0 0 0 0 0 2 0 2 2 <1 2 0 1 <1 1 2 1 1 3 3 2 2 2 2 <1 1 <1 1 1 <1 <1 <1 <1 <1 <1 <1 <.1 <.1 <.1 <.1 <.1 <.1 <.1 0 0 0 0 0 1 1 1 1 1 1 1 1 <.1 <.1 <1 1 1 1 1 <1 1 1 1 1 4 5 10 12 1 1 4 5 3 5 <1 <.1 <.1 <.1 <.1 1 <.1 <1 <.1 <1 1 8 5 8 6 5 6 6 9 1 1 6 6 5 5 5 3 5 5 5 5 h a p p e n d i x h-32 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 908 33184 70 10093 10091 10094 10092 1417 8539 73 74 4776 16514 12137 82 78 16523 4778 76 12146 10694 15721 15720 16516 16517 25032 1923 1722 4747 25031 1924 4785 1747 4786 16081 36486 36487 36488 10083 10087 17089 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans dairy continued cocoa, hot, prepared w/milk cocoa mix with aspartame, added sodium & vitamin a, no added calcium or phosphorus, prepared with water eggnog breakfast drinks carnation instant breakfast classic chocolate malt, prepared w/skim milk, no sugar added carnation instant breakfast strawberry creme, prepared w/skim milk carnation instant breakfast strawberry creme, prepared w/skim milk, no sugar added carnation instant breakfast vanilla creme, prepared w/skim milk, no sugar added ovaltine rich chocolate avor, prepared w/skim milk malted milk, chocolate mix, forti ed, prepared w/milk milkshakes chocolate vanilla ice cream chocolate chocolate, soft serve chocolate fudge, fat free no sugar added light vanilla light vanilla, soft serve sherbet, all avors strawberry vanilla vanilla chocolate swirl, fat free, no sugar added soy desserts tofutti low fat vanilla fudge nondairy frozen dessert tofutti premium chocolate supreme nondairy frozen dessert tofutti premium vanilla nondairy frozen dessert ice milk flavored, not chocolate chocolate pudding chocolate chocolate, sugar free, prepared w/2% milk rice tapioca, ready to eat vanilla vanilla, sugar free, prepared w/2% milk frozen yogurt chocolate, soft serve fruit varieties vanilla, soft serve milk substitutes lactose free fat free calcium forti ed milk low fat milk reduced fat milk whole milk rice rice dream carob rice beverage rice dream vanilla enriched rice beverage rice dream original rice beverage, enriched 1 1 1 1 1 1 1 1 1 1 1 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 2 1 1 2 1 2 1 2 1 2 1 2 1 1 1 1 1 1 1 cup(s) 250 206 193 9 27 cup(s) cup(s) 192 254 177 189 56 343 cup(s) cup(s) 243 273 142 220 2 10 11 13 10 34 21 39 cup(s) 243 134 12 21 273 243 220 134 13 12 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) 9 7 9 3 3 4 4 4 1 2 2 4 2 3 2 2 3 5 5 6 3 5 265 216 223 227 227 164 169 66 87 71 66 86 97 66 66 71 70 60 60 66 66 37 50 42 60 64 40 40 45 43 270 254 143 177 100 109 108 133 127 133 100 120 180 190 91 95 133 73 113 105 142 110 136 100 175 169 116 133 72 113 72 90 46 80 47 240 240 240 240 240 240 240 4 12 115 144 117 90 110 130 160 150 130 120 3 3 3 9 8 8 8 1 1 1 39 21 29 48 40 19 24 22 18 19 29 18 16 20 24 18 20 15 17 23 14 26 28 17 <1 18 24 17 13 13 13 12 32 28 25 cup(s) 144 110 154 3 1 0 <1 0 0 0 0 1 1 0 1 1 0 <1 0 <1 1 <1 0 0 0 0 0 <1 1 <1 1 <1 <.1 2 2 0 0 0 0 0 0 0 0 0 6 3.58 1.69 0.09 0.18 0.00 11.29 0.15 5.67 0.01 0.86 <1 19 1 <1 0.89 0.40 <1 0.45 <1 <1 0.40 0.45 9 6 7 7 8 0 3 2 2 6 7 0 2 11 11 3 2 5 3 6 5 3 4.95 2.17 0.54 3.81 4.28 4.49 5.17 0.00 1.71 1.40 1.12 3.43 4.48 1.77 1.98 2.12 2.43 0.00 0.57 0.65 0.51 1.96 0.23 0.26 0.27 0.31 0.00 0.10 0.09 0.08 0.30 0.00 0.00 0.00 1.00 2.00 2.00 1.72 1.29 0.81 0.61 0.11 0.08 2.78 1.94 0.23 1.50 1.99 0.85 1.31 2.14 2.24 1.21 0.88 1.93 0.16 1.50 10 150 0.00 4 4 4 0 3 5 9 3 2 2 2.61 2.63 2.46 0.00 1.50 3.00 5.00 0.00 0.00 0.00 1.26 1.11 1.14 0.16 0.11 0.15 0 0 0 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-33 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 20 263 1.20 <1 150 90 330 0.75 0.51 58 33 48 493 110 1.58 128 0.10 0.08 0.46 0.33 0.10 13 405 419 171 137 0.52 1.17 27 114 0.04 0.09 0.06 0.51 0.21 0.48 0.16 0.27 0.05 0.13 445 500 4.01 89 632 196 3.38 4.47 100 638 360 3.75 445 4.01 89 570 187 3.38 4.50 100 630 240 3.75 0.35 0.38 0.33 0.38 0.33 0.45 4.45 0.45 0.51 5.08 0.48 100 0.45 4.45 0.45 89 0.51 5.00 0.50 100 500 445 339 299 331 72 103 80 77 135 52 79 84 80 0 0 0 91 94 138 150 130 119 133 190 106 113 103 500 300 300 300 20 300 300 4.01 3.76 0.70 0.23 0.61 0.33 0.36 0.05 0.05 0.14 0.14 0.06 0.00 0.00 0.00 0.00 0.07 0.17 1.04 0.72 1.21 0.33 0.25 380 0.90 0.52 0.22 0.00 0.00 0.00 0.00 0.72 0.00 0.00 89 45 36 27 19 19 9 12 8 9 9 50 10 13 29 21 11 14 19 11 10 13 570 187 3.38 0.45 4.45 0.45 578 231 1.17 904 0.76 0.16 1.32 11.08 1.01 508 415 164 192 137 190 93 124 131 0 8 7 2 138 155 252 215 50 44 60 49 60 44 40 53 90 180 210 56 41 1.09 0.88 0.38 0.48 0.48 0.46 0.46 0.22 0.46 0.29 0.38 211 135 1.07 330 250 136 173 310 253 226 134 0.61 0.38 0.63 0.03 188 176 152 60 71 71 63 130 125 125 125 100 90 90 0.35 0.32 0.30 0.24 41 57 78 91 25 63 78 0 0 0 73 0 73 32 42 100 100 98 58 0.11 0.07 0.03 0.04 0.02 0.04 0.02 0.03 0.03 0.11 0.11 0.20 0.22 0.08 0.05 0.03 0.20 0.50 0.44 0.13 0.13 0.11 0.17 0.07 0.17 0.16 0.28 0.33 0.15 0.11 0.06 0.10 0.09 0.11 0.08 0.06 0.10 0.04 0.03 0.02 0.04 0.03 0.03 0.03 0.04 0.03 0.06 0.05 0.17 0.12 0.06 0.09 0.04 0.03 0.04 0.00 0.25 0.18 0.03 0.06 0.10 0.03 0.03 0.17 0.03 0.05 0.03 0.07 0.06 0.43 0.00 0.26 0.26 0.14 0.24 0.73 0.44 0.11 0.08 0.03 0.03 0 0.10 0.08 0.15 0.20 0.16 0.22 0.08 0.21 0.05 0.05 0.06 0.00 0.84 0.08 1 <1 4 27 30 27 30 27 32 0 0 <1 1 0 <1 1 4 5 <1 0 0 0 1 <1 <1 0 1 1 <1 <1 1 1 0 0 0 0 1 0 0 1 <1 1 1 1 1 2 1 1 1 1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <.1 <1 2 2 7 2 11 8 9 8 9 8 12 4 5 2 1 3 1 1 5 2 5 2 2 h a p p e n d i x 2 3 4 89 19 11 16 11 5 3 5 4 8 3 4 4 7 14 4 6 8 5 4 9 9 9 9 9 27 25 27 22 22 0 17 10 5 19 29 0 0 0 0 9 6 35 10 71 1 35 4 15 1 3 15 20 35 0 0 0 h-34 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans da + code 34750 34749 13840 13839 13836 13835 3615 3617 32101 29638 93 94 32100 5242 38202 10453 34616 34617 96 97 98 99 100 101 102 920 918 4028 6040 1573 2905 25079 8615 25082 25083 25084 25089 1825 6049 1578 1886 1582 1587 8580 1831 1592 h x i d n e p p a dairy continued soy soy dream chocolate enriched soy beverage soy dream vanilla enriched soy beverage vitasoy light chocolate soymilk vitasoy light vanilla soymilk vitasoy rich chocolate soymilk vitasoy vanilla delite soymilk yogurt custard style, fruit avors custard style, vanilla fruit, low fat fruit, nonfat, sweetened w/low calorie sweetener plain, low fat plain, nonfat vanilla, low fat yogurt beverage yogurt smoothie, nonfat, all avors soy yogurt white wave plain silk cultured stony eld farm osoy chocolate-vanilla pack organic cultured stony eld farm osoy strawberry-peach pack organic cultured eggs raw, whole raw, white raw, yolk fried hard boiled poached scrambled, prepared w/milk & butter egg substitute frozen liquid egg beaters seafood fish cod atlantic cod or scrod, baked or broiled atlantic cod, cooked, dry heat eel, raw fish llets baked batter coated or breaded, fried broiled sh steaks poached sh steaks steamed sh llets flounder, baked grouper, cooked, dry heat haddock baked or broiled cooked, dry heat halibut, atlantic & paci c, cooked, dry heat herring, atlantic, pickled jack mackerel, solids, canned, drained octopus, common, cooked, moist heat perch, mixed species, cooked, dry heat paci c rock sh, cooked, dry heat salmon 1 1 1 1 1 1 6 6 1 1 1 1 1 1 1 8 1 1 1 1 1 1 1 1 2 1 4 1 4 1 4 3 3 3 3 3 3 3 3 3 3 3 3 3 4 2 3 3 3 2 7 7 4 4 7 8 7 7 10 11 13 14 12 6 10 5 4 4 6 4 3 6 6 6 90 90 74 17 53 92 78 74 203 14 96 53 30 7 8 6 46 89 156 10 19 16 37 22 17 10 24 13 32 32 46 19 17 19 34 33 60 22 15 15 <1 <1 1 <1 1 <1 3 2 <1 1 0 0 0 1 0 0 0 1 1 0 0 0 1 0 0 0 0 6 1 3 3 0 0 0 0 0 0 0 0 0 0 0 0 0 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) ounce(s) ounce(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) 240 240 237 237 237 237 170 170 245 127 134 184 208 241 208 245 209 245 194 245 245 200 325 210 150 100 70 160 120 190 190 243 122 154 137 208 172 290 ounce(s) 227 120 serving(s) 113 serving(s) 113 item(s) item(s) item(s) item(s) item(s) item(s) 50 33 17 46 50 50 item(s) 122 cup(s) cup(s) cup(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) piece(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) 60 63 61 44 85 85 84 85 86 86 86 85 85 44 85 85 60 57 85 85 85 57 38 29 9 32 37 38 89 44 52 34 65 58 80 0.04 69 68 73 65 62 33 63 61 33 39 51 62 62 0 99 22 197.19 12.46 14.42 24 21 17 15 21 129 112 80 114 100 0 0 0 <1 0 50 95 119 157 88 139 99 103 11 21 23 9 13 25 21 20 10 0 0 0 6 0 4 0 0 0 0 0.42 0 0 0 <.1 0 1 10.44 3 2 1 6 1 0 0 0 0 0 0 0 0 0 <1 1 2 11 4 2 1 2 2 4 4 2 2 4 4 4 4 3 <1 4 <1 3 2 0 3 2 2 5 <.1 4 7 5 5 0.50 0.50 0.50 0.50 0.50 0.50 2.00 2.00 1.82 0.21 2.45 0.28 1.97 1.39 0.00 0.00 0.00 0.00 1.55 0.00 1.59 1.98 1.63 1.54 0.50 0.50 1.00 1.00 0.94 0.77 0.10 1.04 0.12 0.84 0.59 0.00 1.91 0.00 1.95 2.92 2.04 1.90 1.00 1.00 2.50 2.50 0.10 0.08 0.04 0.11 0.01 0.09 0.06 0.00 0.68 0.00 0.70 1.22 0.71 0.68 15 4.49 5.82 2.62 7 2 0 <1 1 10 1.16 0.41 0.00 1.46 0.56 0.00 3.74 1.01 0.00 0.07 0.14 2.01 0.08 2.39 0.37 0.33 0.12 1.15 0.25 0.07 0.14 0.35 1.43 1.05 0.39 0.20 0.40 0.05 0.11 6.12 0.07 2.19 0.87 0.76 0.08 2.17 0.23 0.07 0.13 0.82 7.17 1.26 0.28 0.17 0.38 0.13 0.25 0.81 0.26 5.32 0.84 0.74 0.22 1.44 0.34 0.14 0.26 0.80 1.01 0.94 0.41 0.40 0.50 0.52 1.14 0.56 0 0 0 0 29727 smoked chinook (lox) <.1 66 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-35 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 15 15 12 3 15 5 12 13 5 0 0 0 212 0 205 210 212 211 429 1 1 0 24 47 107 44 28.89 37 33 42 44 40 33 63 35 8 45 82 98 37 13 300 300 300 300 300 40 200 200 338 370 448 488 419 260 300 700 100 100 27 2 21 27 25 27 87 44 33 20 6 12 17 8 15.3 55 48 13 19 18 19 36 51 46 137 90 87 10 1.80 1.80 0.72 0.72 1.08 0.72 0.00 0.00 0.15 0.62 0.20 0.22 0.17 0.22 2.70 0.90 0.72 0.72 0.92 0.03 0.45 0.91 0.60 0.92 1.46 1.19 1.32 1.08 0.22 0.42 0.43 0.32 1.79 0.99 0.86 0.30 0.35 0.97 0.60 1.15 0.91 0.73 1.16 8.11 0.99 0.45 6 0.48 60 40 24 24 40 16 16 32 41 42 47 39 39 100 6 4 1 6 5 6 350 160 0.60 260 200 200 320 320 310 300 434 550 573 625 537 399 580 67 54 18 68 63 67 140 140 110 150 115 90 90 130 139 172 189 162 98 290 30 20 20 70 55 8 94 62 147 0.60 0.90 0.90 0.90 1.64 1.83 2.18 2.38 2.03 1.10 2.25 0.56 0.01 0.38 0.55 0.53 0.55 33 33 0 0 0 0 0 0 27 0.10 34 5 29 0 0 70 0 63 91 85 70 0.15 0.15 0.09 0.09 0.15 0.08 0.17 0.11 0.12 0.10 0.11 0.38 0.03 0.00 0.03 0.03 0.03 0.03 0.05 0.17 0.05 0.07 0.00 0.05 0.49 0.00 0.43 0.56 0.51 0.48 0.07 0.80 0.12 0.07 0.34 0.34 0.34 0.26 0.26 0.40 0.50 0.52 0.57 0.49 0.51 0.43 0.24 0.15 0.09 0.24 0.26 0.24 0.80 0.21 0.11 0.28 0.30 0.26 0.30 5.00 0.04 0.04 0.00 0.04 0.03 0.04 0.12 0.09 0.09 0.12 0.13 0.11 0.15 0.50 0.07 0.00 0.06 0.07 0.06 0.07 15 168 342 1.22 174 0.06 1.04 0.53 0.10 0.14 9 6 4 19 36 17 29 20.39 98 85 25 47 31 22 43 91 5 21 51 32 29 10 128 207 85 119 111 115 0.59 0.82 0.60 7 11 113 0.07 0.07 0.15 0.95 0.17 0.23 0.19 0.85 0.08 0.07 0.20 0.08 0.00 0.08 108 207 231 489 272 529 460 323 225 404 177 339 490 41 110 536 292 442 35 66 43 86 452.2 64 55 42 281 45 39 74 59 522 215 391 67 65 0.26 0.49 1.38 0.49 0.37 0.49 0.43 0.35 0.21 0.43 0.21 0.41 0.45 0.32 0.58 2.86 1.22 0.45 12 887 10 10.19 55 48 12 39 43 16 46 155 74 77 9 60 0.04 0.07 0.13 0.03 0.09 0.06 0.06 0.07 0.06 0.07 0.02 0.03 0.06 0.02 0.02 0.05 0.07 0.04 0.69 3.40 0.41 1.03 0.58 1.02 1.33 0.03 0.07 0.03 0.05 0.09 0.08 0.08 0.06 0.08 0.01 0.02 0.04 0.08 0.08 0.12 0.06 0.10 0.07 1.11 2.14 2.98 2.48 1.78 6.88 5.97 1.92 2.03 0.32 2.05 3.94 6.05 1.98 3.50 3.21 1.62 3.33 0.13 0.24 0.06 0.46 0.08 0.36 0.33 0.22 0.19 0.30 0.15 0.29 0.34 0.10 0.12 0.55 0.12 0.23 99 1134 0.17 15 0.01 0.05 2.67 0.15 60 60 24 24 60 22 26 27 29 27 29 100 24 1 24 23 22 24 37 10 9 60 5 7 13 8 17 13 12 6 7 9 4 11 12 1 3 20 5 9 1 0 0 0 0 0 0 0 0 1 1 2 2 2 2 15 0 0 0 0 0 0 0 0 0 <1 <1 0 0 <1 1 2 3 0 0 0 1 3 0 0 0 0 0 1 7 1 0 0 3 3 1 1 1 1 1 1 1 2 2 0 1 <.1 <1 1 1 1 1 <1 <1 1 <1 1 3 1 0.94 1 1 1 2 1 1 1 1 3 4 31 2 1 2 7 8 9 12 16 7 9 16 15 16 27 25 16 17 32 6 44 7.73 43 37 32 34 40 18 34 40 35 21 76 14 40 22 h a p p e n d i x h-36 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 1594 2938 154 155 1599 1839 1868 16617 1570 1601 1840 1842 1846 159 355 33211 33212 2961 351 33213 33214 2970 8548 1857 16618 1851 1852 8562 1860 1853 8720 152 8715 8584 1865 1854 1862 1855 158 4450 174 33147 4581 4411 4417 4418 4423 4183 4264 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans seafood continued broiled or baked w/butter coho, farmed, raw sardines, atlantic, with bones, canned in oil scallops mixed species, breaded, fried steamed snapper, mixed species, cooked, dry heat squid mixed species, fried steamed or boiled striped bass, cooked, dry heat sturgeon, steamed surimi, formed sword sh, cooked, dry heat tuna, yellow n or ahi, raw tuna, canned light, canned in oil, drained light, canned in water, drained light, no salt, canned in oil, drained light, no salt, canned in water, drained white, canned in oil, drained white, canned in water, drained white, no salt, canned in oil, drained white, no salt, canned in water, drained yellowtail mixed species, raw mixed species, cooked, dry heat shell sh, meat only abalone, mixed species, fried abalone, steamed or poached crab blue crab, canned blue crab, cooked, moist heat dungeness crab, cooked, moist heat clams, cooked, moist heat cray sh, farmed, cooked, moist heat oysters baked or broiled eastern, farmed, raw eastern, wild, cooked, moist heat paci c, cooked, moist heat paci c, raw lobster, northern, cooked, moist heat mussels, blue, cooked, moist heat shrimp mixed species, cooked, moist heat mixed species, breaded, fried beef, lamb, pork beef breakfast strips, cooked corned, canned cured, thin sliced jerky ground extra lean, broiled, well lean, broiled, medium lean, broiled, well regular, broiled, medium rib rib, whole, lean & fat, 1 4" fat, roasted roast bottom round, lean & fat, 1 4" fat, braised 3 3 2 3 3 3 3 3 3 3 3 3 3 2 2 2 2 2 2 2 2 2 3 3 3 2 3 3 3 3 3 3 3 3 3 3 3 3 3 2 3 2 1 3 3 3 3 3 3 ounce(s) ounce(s) item(s) item(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) slice(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) 85 85 24 47 85 85 85 85 85 85 85 85 85 57 57 57 57 57 57 57 57 57 85 85 85 57 85 85 85 85 85 85 85 85 85 85 85 85 85 23 85 57 28 85 85 85 85 85 54 60 <.1 <.1 65 60 55 63 62 59 65 58 60 34 42 34 43 36 41 36 42 42 0.05 51 41 43 66 62 54 69 69 73 60 55 70 65 52 66 0.04 0 49 31 0 46 47 45 46 39 155 136 50 100 90 109 149 90 105 111 84 132 92 113 66 112 66 105 73 105 73 83 23 18 6 8 14 22 15 15 19 17 13 22 20 17 14 17 14 15 13 15 13 13 158.94 25.21 161 177 56 87 94 126 74 90 50 116 139 69 83 146 17 29 12 17 19 22 15 6 4 12 16 8 17 20 0 0 0 5 2 0 7 3 0 0 6 0 0 0 0 0 0 0 0 0 0 0 0 9 10 0 0 1 4 0 3 5 7 8 4 1 6 84 18 205.69 18.18 9.74 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 7 3 5 3 1 6 1 3 4 1 4 1 5 <1 5 <1 5 2 5 2 3 5.71 6 1 1 2 1 2 1 6 1 4 4 2 1 4 0 0.34 1 10.43 101.47 7.07 23 18 116.44 9.42 213 87 0.31 0 2 3.12 0 0 0 0.51 225 231 238 246 320 24 21 24 20 19 0 0 0 0 0 0 0 0 0 0 0 0 7.77 13 1 7.27 13 16 15 18 27 1.16 1.54 2.29 2.83 2.33 1.58 0.36 0.92 1.23 1.24 2.09 1.32 0.31 0.27 0.50 1.60 0.35 0.55 0.97 0.16 1.20 0.20 0.87 0.13 0.87 0.13 0.73 0.45 0.94 0.45 0.73 1.44 1.40 0.25 0.14 0.19 0.14 0.16 0.18 1.38 0.38 1.31 0.87 0.43 0.09 0.72 0.25 1.77 3.24 5.25 0.54 3.08 5.28 6.16 5.89 6.91 2.34 0.11 0.72 2.04 0.13 1.68 0.13 1.68 0.09 1.67 0.09 1.85 0.44 1.41 0.44 1.13 2.21 2.33 0.18 0.12 0.24 0.18 0.15 0.21 2.18 0.13 0.53 0.66 0.30 0.14 0.86 0.17 3.24 3.8 5.07 0.48 3.21 5.88 6.87 6.56 7.70 1.82 0.51 0.85 0.73 0.38 1.00 0.24 1.64 0.19 1.64 0.19 1.69 0.63 1.92 0.63 0.81 1.52 1.42 0.18 0.25 0.58 0.35 0.47 0.35 1.88 0.50 1.65 1.52 0.76 0.08 1.03 0.37 4.32 0.35 0.54 0.04 0.28 0.50 0.59 0.56 0.65 10.71 11.42 0.94 ounce(s) 85 44 241 24 15 5.71 6.63 0.58 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-37 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 15 10 1.02 0.29 108 0.70 377 383 99 40 0.56 0.37 95 121 0.31 40 43 34 28 27 40 221 227 88 63 26 43 38 10 17 10 17 18 24 18 24 20 21 34 33 31 16 11 8 5 14 7 6 7 6 2 8 2 8 31 60.34 13 24.64 80 143 50 85 65 57 116 42 21 89 85 43 61 28 31 50 57 88 50 78 43 37 37 77 14 7 52 5.71 48 0.38 0.22 0.20 0.86 0.63 0.92 0.59 0.22 0.88 0.62 0.79 0.87 0.79 0.87 0.37 0.55 0.37 0.55 0.28 0.53 3.23 4.85 0.48 0.77 0.37 23.77 0.94 5.30 4.91 10.19 7.82 4.35 0.33 31 27 26 9 27 31 32 29 43 30 37 29 43 18 15 18 15 19 19 19 19 48 69 22 28 49 15 28 38 28 81 37 19 30 228 29 34 48 16 10 30 9 26 17 35 15 13 10 13 10 3 3 14 3 16 26.35 2 1 2 26 145 13 60 7 46 124 69 22 0.26 0.49 0.37 1.48 1.49 0.43 0.36 0.28 1.25 0.44 0.51 0.44 0.51 0.44 0.27 0.27 0.27 0.27 0.29 0.56 0.81 1.38 2.28 3.59 4.65 2.32 1.26 72.22 32.23 154.37 28.25 14.14 2.48 77 155 238 444 237 192 279 239 95 314 378 118 134 117 134 189 134 189 134 216 366 48 260 356 75 389 122 98 31 202 192 28 28 225 214 28 28 241 295 212 275 347 534 202 126 105 239 257 143 299 314 502 980 189 237 321 95 82 418 151 359 180 90 323 2.27 17 32.29 238 457.29 22 42.5 166 33 150.44 56.95 2.63 1.07 155 190 191.25 292.39 1.33 1.17 58 47.59 26.89 73 45 13.63 2.03 10 3 5.67 84 74 86 77 72 82 8 9 10 9 9 5 0.7 1.77 1.58 1.53 2.35 1.79 2.08 2.07 1.96 6.1 12 11 14.48 93.11 509.17 116 140 855 1582 169.54 628.49 21 18 20 17 16 314 256 297 248 252 70 65 76 71 54 1.43 3.03 2.49 2.3 5.47 4.56 5.27 4.40 4.45 2.65 19 240 43 4.17 0 0 0 0 0 0 0 0 0 0 0.14 0.08 1.15 0.05 0.09 8.33 5.79 0.19 0.56 0.01 0.49 0.05 1.25 0.04 0.01 0.05 0.05 0.02 0.10 0.07 0.02 0.04 0.37 0.02 0.02 0.02 0.02 0.01 0.00 0.01 0.00 0.08 0.14 0.19 0.29 0.05 0.09 0.05 0.13 0.04 0.07 0.09 0.16 0.11 0.06 0.01 0.03 0.1 0.02 0.02 0.03 0.04 0.06 0.04 0.05 0.03 0.06 0.16 0.05 0.69 0.06 0.00 0.29 0.39 1.17 0.53 0.54 0.43 0.50 0.19 1.30 0.48 6.74 1.04 1.56 0.99 0.72 0.85 0.36 1.17 0.07 0.13 0.00 0.14 0.39 0.32 0.03 0.07 0.02 0.10 0.04 0.07 0.04 0.07 0.04 0.04 0.02 0.04 0.02 0.02 0.04 0.11 0.13 0.05 0.04 0.17 0.36 0.07 0.06 0.06 0.15 0.38 0.20 0.06 2.55 0.03 0.11 0.05 0.12 0.12 0.04 0.27 0.18 0.20 0.16 2.21 1.70 2.17 8.31 0.19 10.02 8.33 7.06 7.53 7.03 7.53 6.63 3.29 6.63 3.29 3.86 7.41 1.62 1.90 0.78 2.81 3.08 2.85 1.42 1.04 1.08 2.11 3.08 1.71 0.91 0.09 2.20 2.6 1.46 2.07 1.85 0.49 4.97 4.39 5.07 4.90 0.05 0.04 0.29 0.19 0.03 0.32 0.77 0.06 0.20 0.06 0.20 0.24 0.12 0.24 0.12 0.09 0.15 0.13 0.22 0.09 0.15 0.15 0.09 0.11 0.05 0.05 0.10 0.08 0.04 0.07 65 0.11 0.08 0.07 0.11 0.16 0.05 0.27 0.22 0.26 0.23 0.14 2.86 0.20 0.06 0.17 0.20 3.17 0.28 4 11 3 23 5 12 4 9 14 2 2 2 3 2 3 2 3 1 3 1 2 1 0 1 2 1 4 3 0 0 0 1 1 0 0 0 0 0 0 0 0 2 2 2 1 3 1 1 4 2 1 2 <1 1 2 1 2 1 1 1 1 41 11 13 13 42 44 40 24 52 31 43 46 43 46 34 37 34 37 2 3.4 2 2.46 1 1.06 21 39.77 12 6 24 43 36 25 9 8 15 12 13 9 9 12 2 3 2 3 3 19 <1 3 4 5 11 7 0 20 1 1 <1 6 9 84 3 15 14 30 24 14 3 76 44 18 34 40 54 29 54 61 131 65 36 3 20.39 2 1.27 1 1.58 34 35.44 1.8 8 5 38.05 9 8 9 8 6 9 0 0 0 0 0 0 0 0 0 0 0.77 1 1 0.28 2 2 2 2 2 2 6.05 36 13 3.03 19 25 22 16 19 27 h a p p e n d i x h-38 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans beef, lamb, pork continued da + code 169 4147 4161 5853 4295 4285 1757 4349 4348 4360 188 4447 3275 3287 3290 bottom round, separable lean, 1 4" fat, roasted 3 chuck, arm pot roast, lean & fat, 1 4" fat, braised chuck, blade roast, lean & fat, 1 4" fat, braised chuck, blade roast, separable lean, 1 4" trim, pot roasted eye of round, lean, 1 4" fat, roasted eye of round, lean & fat, 1 4" fat, roasted 3 3 3 3 3 steak rib, small end, lean, 1 4" fat, broiled short loin, t-bone steak, lean, 1 4" fat, broiled short loin, t-bone steak, lean & fat, 1 4" fat, broiled top loin, prime, lean & fat, 1 4" fat, broiled variety liver, pan fried tongue, simmered lamb chop loin, domestic, lean & fat, 1 4" fat, broiled shoulder, arm, domestic, lean & fat, 1 4" fat, braised shoulder, arm, domestic, lean, 1 4" fat, braised leg 3264 domestic, lean & fat, 1 4" fat, cooked 183 182 187 186 3375 3406 161 29229 35422 16561 189 1316 29215 32671 32672 32682 32603 32481 32478 32471 32468 32696 32693 rib domestic, lean, 1 4" fat, broiled domestic, lean & fat, 1 4" fat, broiled shoulder arm & blade, domestic, choice, lean, 1 4" fat, roasted arm & blade, domestic, choice, lean & fat, 1 4" fat, roasted variety brain, pan fried tongue, braised pork cured bacon, cured, broiled, pan fried or roasted bacon, canadian style, cured breakfast strips, cured, cooked ham, smoked or cured, lean, cooked ham, cured, boneless, 11% fat, roasted ham, cured, extra lean, 5% fat, roasted ham, cured, extra lean, 4% fat, canned chop loin, blade, lean & fat, pan fried loin, center cut, lean & fat, pan fried loin, center rib, boneless, lean & fat, braised loin, center rib, lean, broiled loin, whole, lean, braised loin, whole, lean & fat, braised leg or ham rump portion, lean & fat, roasted whole, lean & fat, roasted ribs loin, country style, lean, roasted loin, country style, lean & fat, roasted shoulder 32629 arm picnic, lean, roasted h x i d n e p p a ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) slice(s) ounce(s) slice(s) slice(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 13 57 34 42 85 85 57 85 85 85 85 85 85 85 85 85 85 85 0.05 160.64 24.45 41 40 282 293 23 23 0.04 55 209.1 27.45 149 25 51 49 52 43 43 53 49 44 38 42 46 50 40 54 48 52 49 2 38 9 28 55 58 42 42 45 49 48 52 50 48 47 49 43 51 195 188 174 274 275 149 236 269 294 237 250 200 307 173 235 232 234 68 89 156 66 151 123 68 291 236 217 186 174 203 214 232 210 279 194 23 24 23 19 22 23 16 21 26 30 21 24 19 21 19 14 18 5 12 10 11 19 18 10 18 25 22 26 24 23 25 23 23 20 23 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 <1 1 <1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6.26 2.13 2.83 0.24 20 22 7.97 8.68 0.77 8.70 9.44 0.78 10.15 5 3.94 1.76 4.37 2.06 0.33 0.15 4.23 4.66 0.39 3.84 4.01 0.27 3.05 4.23 0.26 8.29 9.58 0.75 8.16 8.61 0.73 1.27 6.91 0.56 8.59 0.49 0.56 0.17 0.71 8.36 8.25 1.43 8.39 8.65 1.45 4.28 5.24 0.78 7.51 7.50 1.28 3.95 10.80 4.43 10.30 1.00 2.01 3.47 3.71 0.81 7.17 6.94 1.38 4.82 6.66 3.42 8.50 1.94 1.06 1.73 1.26 4.34 0.77 2.65 1.54 0.86 8.65 5.11 5.21 2.94 2.87 4.35 4.47 5.50 4.52 7.83 2.33 1.79 5.58 1.06 3.77 2.23 1.25 9.97 6.00 6.13 3.78 3.54 5.15 5.42 6.70 5.49 9.36 0.57 0.36 1.92 0.27 1.20 0.46 0.22 2.64 1.62 1.12 0.53 0.60 1.00 1.17 1.43 0.94 1.71 3.66 5.09 1.02 0 11 10 9 21 20 4 19 20 20 12 18 11 25 9 17 19 17 5 4 12 2 8 5 3 24 14 13 8 8 12 12 15 13 22 11 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 2 2 3 1 3 3 2 3 3 3 3 3 3 3 3 3 3 3 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-39 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 66.3 4.25 2.66 23.79 332.35 56.09 3.92 84 88 9 11 73.94 59 11.05 4 61 68 50 58 67 324 112 85 102 103 82 77 84 74 78 2128 161 14 28 36 23 50 45 22 72 78 62 69 67 68 82 80 79 78 81 5 11 5 7 8 5 4 17 21 22 14 14 16 16 17 18 9 1 5 5 3 7 7 3 26 23 4 26 15 18 10 12 25 21 8 2.64 2.64 3.12 1.66 1.56 2.18 3.11 2.56 1.89 5.24 2.22 1.54 2.03 2.30 1.60 1.88 1.60 1.81 1.67 1.73 2.24 0.18 0.39 0.67 0.40 1.14 1.26 0.53 0.75 0.77 0.78 0.70 0.96 0.91 0.89 0.86 1.10 0.90 1.21 16 16 19.54 23 20 23 22 18 20 19 13 20 22 25 20 25 20 21 20 19 14 4 10 9 9 19 12 10 18 25 14 24 17 16 23 19 20 20 17 209 196 51 54 223.55 60.34 336 308 335 278 234 294 298 156 278 260 287 264 266 230 225 213 304 134 71 195 158 133 348 244 206 282 361 329 357 329 318 318 299 297 293 299 53 50 59 65 58 54 65 55 65 61 65 61 72 65 58 56 133 57 291 799 714 557 1275 1023 712 57 68 34 55 43 41 53 51 25 44 68 0 0 0 0 0 0 0 0 0 0 0.06 0.2 3.45 0.31 10.19 0.06 0.19 0.20 2.70 0.24 0.06 0.15 0.20 2.06 0.22 0.06 0.08 0.23 0.14 0 3.19 0.24 0.32 0.07 0.15 0.14 2.97 0.30 0.09 0.12 0.19 4.08 0.34 0.09 0.12 0.21 3.94 0.33 0.08 0.19 0.18 3.29 0.28 0.07 0.15 3.96 0.31 8 4 6 6 7 7 6 6 5.81 7.07 8.72 4.03 3.69 5.94 4.34 3.56 3.85 4.45 34.77 6582 0 0.15 0.02 0.39 0.25 2.91 0.25 14.85 2.97 0.87 0.13 221 6 2.96 5.17 6.21 3.79 4.48 3.40 5.13 4.45 1.70 2.54 0.44 0.79 1.25 1.08 2.10 2.45 1.09 2.71 1.96 1.76 2.02 2.11 2.02 2.40 2.52 3.24 2.01 3.46 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 3 2 2 2 2 2 3 3 2 3 2 0.09 0.11 0.21 6.04 0.11 0.06 0.13 0.21 5.66 0.09 0.06 0.15 0.23 5.38 0.11 0.09 0.12 0.21 5.66 0.11 0.09 0.08 0.15 0.10 0.21 0.19 5.57 5.95 0.13 0.09 0.08 0.15 0.22 4.90 0.13 0.08 0.12 0.20 5.23 0.11 0.14 0.07 0.31 0.36 3.87 3.14 0.20 0.14 0.05 0.43 0.25 0.29 0.62 0.64 0.47 0.53 0.97 0.45 0.95 0.56 0.54 0.64 0.54 0.49 0.76 0.49 0.04 0.12 0.09 0.11 0.26 0.21 0.10 0.17 0.21 0.21 0.25 0.18 0.20 0.19 0.19 0.03 0.10 0.13 0.11 0.28 0.17 0.13 0.25 0.26 0.21 0.28 0.23 0.22 0.28 0.27 0.29 0.29 1.40 3.53 2.58 2.11 5.23 3.42 3.01 3.36 4.76 3.67 5.25 3.90 3.76 3.96 3.89 3.97 3.67 0.04 0.22 0.12 0.20 0.26 0.34 0.26 0.29 0.40 0.26 0.40 0.33 0.31 0.27 0.34 0.37 0.38 0.30 3.67 0.35 15 15 19 15 18 12 21 18 6 3 <1 2 1 2 3 3 3 3 5 3 3 3 3 3 9 4 4 4 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 20 6 0 0 0 0 0 0 0 1 1 <1 <1 1 1 <1 <1 <1 <1 <1 2.29 23.29 3 2 2.09 2 21 21 22.69 23 2 3 2 2 2 71 3 2 2 2 2 2 2 2 2 20 5 <1 <1 1 <1 1 1 <1 1 1 <1 1 <1 <1 1 1 1 1 1 22 19 9 10 19 28 11 23 32 32 22 26 20 24 22 10 24 8 14 8 17 17 8 30 33 28 40 41 39 40 39 36 32 33 h a p p e n d i x h-40 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans da + code 32626 3366 3367 3391 3319 1732 beef, lamb, pork continued arm picnic, lean & fat, roasted rabbit domesticated, roasted domesticated, stewed veal liver, braised rib, lean only, roasted deer or venison, roasted poultry chicken 29562 flaked, canned fried 29632 35327 36413 35389 36414 35406 35484 29580 35409 35486 35138 35136 35132 3174 1268 1270 1286 1287 35507 35524 1297 3256 222 219 220 3263 1302 1303 breast, meat only, breaded, baked or fried broiler breast, meat only, fried broiler breast, meat & skin, our coated, fried broiler drumstick, meat only, fried broiler drumstick, meat & skin, our coated, fried broiler leg, meat only, fried broiler wing, meat only, fried patty, llet, or tenders, breaded, cooked roasted, meat only broiler chicken leg broiler chicken wing roasting chicken, dark meat roasting chicken, light meat roasting chicken stewed meat only, stewed gizzard, simmered liver, simmered duck domesticated, meat & skin, roasted domesticated, meat only, roasted goose domesticated, meat & skin, roasted domesticated, meat only, roasted liver p t , smoked, canned turkey ground turkey, cooked roasted, fryer roaster breast, meat only roasted, dark meat, meat only roasted, light meat, meat only patty, batter coated, breaded, fried turkey roll, light meat turkey roll, light & dark meat h x i d n e p p a processed meats beef 1331 corned beef loaf, jellied, sliced 13458 13461 13459 13565 bologna made w/chicken, pork, & beef light, made w/pork, chicken, & beef beef turkey chicken 13562 oven roasted white chicken ham 13581 13777 13778 8614 honey glazed, traditional carved deli sliced cooked deli sliced honey pork & beef mortadella, sliced 3 3 3 3 3 3 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 4 3 3 3 3 1 2 2 2 1 1 1 1 1 2 1 1 2 ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) 85 85 85 85 85 85 44 52 50 51 55 55 270 167 175 163 150 134 20 25 26 24 22 26 0 0 0 3 0 0 ounce(s) 57 0.03 97.47 10.37 0.05 ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) ounce(s) tablespoon(s) ounce(s) ounce(s) ounce(s) ounce(s) item(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85 52 85 85 85 85 94 57 57 57 28 28 28 28 28 45 28 28 46 44 51 48 53 48 52 51 42 55 53 57 58 57 0.05 58 57 44 55 44 49 19 51 58 54 56 47 41 40 39 15 18 15 19 20 24 193 159 189 166 208 177 179 241 162 173 151 130 142 25 28 27 24 23 24 26 14 23 26 20 23 21 150.44 23.19 124 142 286 171 259 202 240 200 115 159 133 266 83 84 87 90 60 90 50 40 50 30 35 143 26 21 16 20 21 25 6 23 26 24 25 13 11 10 13 3 3 3 3 4 8 5 5 8 7 <1 1 0 1 1 0 13 0 0 0 0 0 0 0 1 0 0 0 0 2 0 0 0 0 15 <1 1 0 1 2 1 1 1 1 1 1 1 0 0 0 0 0 0 0 <1 0 <.1 0 <.1 0 0 <1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 0 0 0 0 0 0 0 0 0 0 0 0 20 7.47 9.12 2.00 7 7 5 6 3 2.04 2.13 1.69 1.77 1.06 1.84 1.93 0.97 2.26 0.75 1.33 1.39 0.88 0.57 0.53 0.26 5.87 1.62 2.32 1.29 7 4 8 7 12 8 8 15 7 7 7 3 6 5.7 2 6 24 10 19 11 23 11 1 6 3 17 4 4 3 8 4 8 4 3 2 1 1 12 1.62 1.10 2.08 1.81 3.11 2.12 2.13 2.66 1.46 2.98 2.50 4.61 2.92 2.62 1.73 0.91 1.67 1.68 2.75 1.89 1.76 4.62 7.25 1.87 1.95 1.92 2.07 0.92 1.54 1.56 0.57 1.75 8.22 3.54 5.84 3.88 7.51 2.88 0.20 2.06 0.88 4.41 1.15 1.16 2.59 2.22 2.82 1.29 2.13 2.03 0.45 1.20 10.97 3.15 8.72 3.69 13.32 4.16 0.11 1.39 0.48 7.02 1.42 1.30 1.68 1.51 1.70 0.79 1.28 1.3 0.30 1.08 3.10 1.22 2.14 1.31 0.44 2.75 0.17 1.84 0.73 4.43 0.99 1.01 1.47 1.52 0.18 3.00 1.50 3.50 1.00 4.05 2.04 4.26 1.09 1.10 0.43 0.31 0.98 0.50 0.50 0.50 0.50 4.37 0.68 0.39 0.39 5.23 0.18 0.11 0.11 1.44 0.11 0.08 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-41 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 80 70 73 434 98 95 16 16 17 5 10 6 1.00 1.93 2.01 4.34 0.82 3.80 14 18 17 17 20 20 276 326 255 280 264 285 60 40 31 66 82 46 2.93 1.93 2.01 9.55 3.82 2.34 2 0 0 17973 0 0 0.44 0.26 3.33 0.30 0.08 0.05 0.15 0.05 0.15 0.37 0.58 0.31 0.18 0.14 2.43 0.25 0.51 7.17 6.09 11.18 6.38 5.70 0.40 0.29 0.78 0.23 3 9 8 281 12 35.34 7.98 0.9 6.84 148.19 410.39 0.8 19.37 0 0.07 3.6 0.19 67 77 76 80 77 84 71 51 80 72 64 64 64 19 14 14 10 10 11 13 14 10 14 9 11 10 70.55 315 479 11.89 14 9 71 76 77 82 78 87 71 72 59 58 24 31 27 30 15 20 20 15 25 15 15 26 9 10 11 12 36 21 10 27 16 13 23 18 6 0 0 0 40 0 0 0 0 8 1.05 0.97 1.01 1.12 1.14 1.19 0.97 1.06 1.11 0.99 1.13 0.92 1.03 0.99 2.71 9.89 2.30 2.30 2.41 2.44 2.86 1.64 1.30 1.98 1.15 2.07 0.73 0.77 1.16 0.36 0.36 0.36 0.36 0.36 0.72 0.00 0.00 0.64 25 26 26 20 20 21 18 17 20 18 17 20 18 17.85 3 21 14 17 19 21 7 20 25 20 24 14 9 10 6 6 6 4 6 7 5 223 235 220 212 195 216 177 450 67 65 82 76 82 77 0.84 0.92 0.94 2.74 2.46 2.53 1.80 209 452 0.88 206 179 191 201 195 153 152 224 173 214 280 330 72 230 248 247 259 259 142 153 57 43 46 47 43 85 75 77 78 81 43 64 59.5 48 65 50 55 60 65 362 91 44 67 54 752 277 332 2.43 1.82 1.81 0.66 1.29 1.69 3.76 3.38 1.58 2.21 2.23 2.70 0.48 2.43 1.48 3.79 1.73 1.35 0.88 1.13 540 2.32 290 310 310 270 0.40 0.45 0.57 0.52 350 0.32 560 240 240 573 0.97 14 7 10 12.75 0 3384 54 20 18 10 521 0 0 0 0 10 0 0 0 0 0 0 0 0 0 0 0 0 0.08 0.07 0.07 0.07 0.07 0.07 0.04 0.08 0.06 0.04 0.05 0.05 0.05 0.04 0.02 0.25 0.15 0.22 0.07 0.08 0.05 0.05 0.04 0.05 0.05 0.09 0.05 0.05 0.00 0.01 0.05 0.23 0.23 0.17 0.70 0.59 0.59 0.29 0.08 0.54 0.08 1.18 0.07 0.19 0.10 0.11 0.11 0.20 0.19 0.21 0.11 10.98 12.57 11.69 5.23 5.13 5.69 6.16 0.47 0.54 0.49 0.33 0.30 0.33 0.50 0.12 5.71 0.26 0.20 0.11 0.16 0.08 0.13 0.13 0.18 1.69 0.23 0.40 0.28 0.33 0.16 0.14 0.11 0.21 0.11 0.18 0.13 0.16 5.37 6.22 4.88 8.90 6.70 5.19 2.65 9.39 4.10 4.34 3.55 3.47 1.31 4.10 6.37 3.10 5.81 2.16 3.97 2.72 0.32 0.50 0.26 0.46 0.35 0.22 0.06 0.64 0.15 0.21 0.32 0.40 0.03 0.33 0.48 0.31 0.46 0.19 0.18 0.15 0.06 1.00 0.07 0.03 0.68 0.05 0.10 0.07 1.23 0.06 4 3 5 8 9 8 3 9 7 3 6 3 4 5.09 4 491 5 9 2 10 31 6 5 8 5 26 2 3 5 4 1 <1 0 0 1 0 0 0 0 0 0 0 0 0 0 <1 0 0 0 0 0 0 0 24 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 7 6 72 1 0.16 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 <1 29 33 33 16 9 11 22 20 17 16 16 22 19 21 17 22 21 0.18 1 14 17.76 35 70 <1 <1 <1 <1 5 <1 <1 <1 <1 <1 <1 <1 1 <1 1 17 19 19 22 23 32 27 35 27 19 13 17 10 10 h a p p e n d i x h-42 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans da + code 1323 1324 37296 37257 35338 37299 37298 1329 1330 8600 202 1293 3261 37275 37307 1333 37285 37313 206 37272 3262 7162 8620 8619 37273 1336 37294 32419 1318 16049 13606 16047 16048 13583 13604 13567 13596 13597 866 686 869 16886 31608 31609 31613 31614 687 688 689 856 857 h x i d n e p p a processed meats continued pork olive loaf pork pickle & pimento loaf sausages & frankfurters beerwurst beef beer salami (bierwurst) beerwurst pork beer salami berliner, pork & beef braunschweiger pork liver sausage bratwurst pork, cooked cheesefurter or cheese smokie, beef & pork chorizo, beef & pork frankfurter, beef frankfurter, beef & pork frankfurter, chicken frankfurter, turkey italian sausage, pork, cooked kielbasa, kolbassa, pork & beef knockwurst or knackwurst, beef & pork pepperoni, beef & pork polish sausage, pork salami, beef, cooked, sliced salami, pork, dry or hard salami, turkey sausage, breakfast, turkey smoked sausage, beef & pork smoked, sausage, pork smoked, sausage, pork link summer sausage, thuringer, or cervelat, beef & pork vienna sausage, cocktail, beef & pork, canned spreads pork & beef sandwich spread ham salad spread turkey breast, hickory smoked, slices breast, hickory smoked fat free breast, honey roasted, slices breast, oven roasted, slices breast, traditional carved breast, oven roasted, fat free turkey ham, 10% water added turkey pastrami turkey salami beverages alcoholic beer ale, mild beer beer, light beer, nonalcoholic budweiser beer bud light beer michelob beer michelob light beer gin, rum, vodka, whiskey distilled alcohol, 80 proof distilled alcohol, 86 proof distilled alcohol, 90 proof distilled alcohol, 94 proof distilled alcohol, 100 proof liqueurs 3142 33187 coffee liqueur, 63 proof coffee liqueur, 53 proof 2 2 1 1 1 1 1 1 2 1 1 1 1 1 21 8 2 1 2 2 1 2 21 2 2 2 1 2 1 4 1 4 1 1 1 1 2 1 1 2 2 12 12 12 12 12 12 12 12 1 1 1 1 1 1 1 slice(s) slice(s) slice(s) slice(s) ounce(s) slice(s) piece(s) item(s) ounce(s) item(s) item(s) item(s) item(s) item(s) ounce(s) ounce(s) slice(s) slice(s) slice(s) slice(s) slice(s) ounce(s) ounce(s) ounce(s) piece(s) ounce(s) piece(s) tablespoon(s) cup(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) ounce(s) ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) 57 57 29 21 28 15 74 43 57 45 57 45 45 68 61 57 11 57 46 13 57 100 57 57 76 57 16 60 60 56 28 56 56 45 28 28 56 56 360 356 354 360 355 355 355 355 28 28 28 28 28 35 35 33 32 17 13 17 0 42 23 18 23 32 26 28 34 37 31 3 31 28 5 31 67 31 22 30 29 10 36 38 20 332 336 337 353 328 335 323 330 19 18 17 17 16 14 11 133 149 7 7 74 50 65 51.34 181 4 3 4 1.97 10 5 3 1 <1 1 0.34 2 141 258 149 174 116 102 220 135 174 55 163 119 52 125 190 181 221 295 190 45 141 130 50 25 60 50 40 25 35 70 120 148 118 99 32 143 110 155 134 64 70 73 76 82 6 14 5 7 6 6 14 10 6 2 8 6 3 8 17 7 13 17 9 2 5 5 11 4 11 11 9 4 5 11 8 1 1 1 1 1 1 1 1 0 0 0 0 0 107 117 <.1 <.1 1 1 2 1 3 1 1 2 2 <1 2 1 <1 11 <1 1 1 2 <1 <1 7 6 1 1 2 1 0 1 0 1 1 13 6 5 5 11 7 13 12 0 <.1 0 0 0 11 16 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 <.1 0 0 0 0 0 <1 0 0 0 0 0 0 0 0 0 0 1 <1 0 0 0 0 0 0 0 0 0 0 0 0 0 9 12 6 4 5 4.48 14 12 22 13 16 9 8 17 9 16 5 14 10 4 5 13 16 18 24 17 4 10 9 0 0 0 0 1 0 1 2 9 0 <1 0 0 0 0 0 0 0 0 0 0 0 <1 <1 3.32 4.45 2.50 1.32 1.72 1.52 5.15 4.52 8.15 5.26 6.14 2.49 2.65 6.14 3.40 5.79 1.77 4.91 4.54 1.52 1.98 3.90 5.54 6.42 8.58 4.47 5.45 2.69 1.89 2.27 2.08 6.73 5.89 10.43 6.44 7.79 3.82 2.51 8.13 4.44 7.26 2.32 6.42 4.90 2.05 1.80 6.23 6.94 8.30 11.09 1.10 1.47 0.21 0.50 0.45 0.52 1.51 1.30 1.96 0.53 1.56 1.82 2.25 2.23 1.06 1.66 0.48 1.46 0.48 0.48 1.43 3.33 2.23 2.13 2.85 6.82 7.35 0.68 1.49 2.01 0.27 3.59 3.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.00 2.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.04 4.57 4.32 0.00 0.00 0.00 0.00 0.07 0.00 0.22 2.92 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 1.54 1.62 0.00 0.00 0.00 0.00 0.14 0.00 0.31 2.30 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.04 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-43 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 22 21 18 12 13 23.69 44 62 54 3 2 3 1.36 33 29 50 24 29 45 48 53 41 34 9 40 33 10 45 92 33 39 52 43 8 23 22 25 10 20 20 20 10 20 40 50 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 25 5 6 6 43 48 16 27 6 1 7 3 2 42 57 7 17 23 7 2 7 5 0 0 0 0 0 0 0 0 40 18 18 18 25 18 18 18 18 0 0 0 0 0 <1 <1 0.31 0.58 0.44 0.16 0.33 1.42 0.96 0.46 0.90 0.68 0.66 0.90 0.83 1.02 0.88 0.37 0.15 0.82 1.01 0.17 0.87 2.20 0.43 0.66 0.88 1.44 0.14 0.47 0.35 0.72 0.00 0.72 0.72 0.72 0.00 0.36 0.72 0.72 0.11 0.07 0.14 0.04 0.11 0.14 0.11 0.14 0.01 0.01 0.01 0.01 0.01 0.02 0.02 11 10 4 3 4 1.67 11 169 193 67 53 80 843 789 265 261 368 27.49 131.54 157 412 0.78 0.80 0.71 0.36 0.70 0.42 1.70 0.97 1.93 1.11 1.05 0.47 1.40 1.62 1.23 0.94 0.28 1.10 0.81 0.54 1.76 2.07 0.71 1.60 2.14 89 226 70 95 38 81 207 169 113 38 102 86 48 225 188 101 191 255 465 700 513 638 617 642 627 566 527 224 546 524 289 616 665 517 851 1137 154 704 1.45 16 66 90 81 89 64 90 89 64 89 64 1 1 1 1 1 10 10 152 0.26 608 547 730 300 640 620 540 330 310 590 500 18 14 11 18 9 9 9 9 <1 <1 <1 <1 <1 3 3 0.61 0.66 0.73 0.04 0.11 0.04 0.07 0.11 0.07 0.11 0.01 0.01 0.01 0.01 0.01 0.01 0.01 34 12 0 0 0 641.01 0 20 0 0 10 18 0 0 0 0 0 0 0 0 1 0 7 0 0 0 0 0.17 0.17 0.02 0.12 0.11 0.03 0.37 0.11 0.36 0.02 0.11 0.03 0.02 0.42 0.14 0.19 0.04 0.29 0.05 0.12 0.24 0.04 0.11 0.40 0.53 0.14 0.24 0.00 0.12 0.09 0.14 0.10 0.28 0.09 0.14 0.00 0.07 0.14 0.15 0.14 0.04 0.04 0.06 0.23 0.14 0.07 0.17 0.07 0.07 0.05 0.08 0.16 0.13 0.08 0.03 0.08 0.09 0.04 0.17 0.12 0.06 0.15 0.20 1.04 1.17 0.99 0.69 0.88 1.27 2.37 1.25 2.91 1.07 1.50 1.39 1.86 2.83 1.75 1.55 0.55 1.96 1.49 0.72 2.26 3.55 1.67 2.57 3.43 0.13 0.11 0.05 0.07 0.06 0.05 0.16 0.06 0.30 0.04 0.07 0.14 0.10 0.22 0.11 0.10 0.03 0.11 0.08 0.07 0.24 0.29 0.09 0.20 0.27 0.09 0.12 0.19 2.44 0.15 0.01 0.02 0.26 0.02 16 0 0.10 0.26 1.04 1.04 0.08 0.07 1.04 1.26 0.07 0.09 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.02 0.02 0.03 0.02 0.02 0.03 0.02 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.10 0.09 0.11 0.10 0.09 0.11 0.09 0.11 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.63 1.61 1.39 1.63 1.61 1.39 1.61 1.39 0.00 0.00 0.00 0.00 0.00 0.05 0.05 0.18 0.12 0.18 0.18 0.12 0.18 0.12 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1 3 1 1 1 1 1 1 2 2 2 4 3 3 1 <1 1 1 <1 6 5 1 3 4 1 1 1 1 21 14 22 21 15 21 15 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 0 12 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 <1 1 3.05 1 9 8 5 4 8.81 16 1 1 1 1 <1 <1 1 1 1 <1 1 1 <1 1 <1 <1 1 1 3 <1 1 <1 <.1 <.1 <.1 <.1 <.1 <.1 <.1 <.1 0 0 0 0 0 0 0 7 12 4 8 8 7 15 11 8 10 7 3 11 0 12 16 12 3 6 11 2 2 4 4 4 4 0 0 0 0 0 <1 <1 h a p p e n d i x 6 10 6 6 5 6 12 10 6 2 8 6 3 15 18 7 11 14 8 1 5 6 6 21 18 32 21 18 21 18 0 0 0 0 0 1 1 h-44 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 736 858 861 690 1481 1811 692 12010 12031 693 9522 1415 9524 1412 31899 695 694 1876 29392 29391 3145 1414 2391 29389 29388 696 31898 12034 12044 731 9520 16882 16883 16880 16881 732 29357 6012 260 266 268 31143 17372 17225 14266 10080 10099 10096 16056 16054 16055 733 33179 1877 734 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans beverages continued cordials, 54 proof wine champagne, domestic red wine, california sweet dessert wine white wine wine cooler carbonated club soda coca-cola classic cola soda coke diet cola soda cola cola soda, decaffeinated cola, low calorie w/aspartame cola, decaffeinated, low calorie w/aspartame cream soda diet 7 up ginger ale grape soda lemon lime soda mountain dew diet soda mountain dew soda orange soda pepper-type soda pepper-type or cola soda, low calorie w/saccharin pepsi diet cola soda pepsi regular cola soda root beer 7 up sprite diet soda sprite soda coffee brewed brewed, decaffeinated cappuccino cappuccino, decaffeinated espresso espresso, decaffeinated instant, prepared fruit drinks crystal light low calorie lemonade drink fruit punch drink w/added vitamin c, canned grape drink, canned lemonade, from frozen concentrate limeade, from frozen concentrate gatorade thirst quencher, all avors kool-aid (lemonade/punch/fruit drink) kool-aid sugar free, low calorie tropical punch mix, prepared odwalla strawberry c monster fruit drink odwalla strawberry lemonade quencher snapple fruit punch snapple kiwi strawberry slim fast ready to drink shake dark chocolate fudge french vanilla strawberries n cream tea tea, prepared decaffeinated, prepared herbal, prepared instant tea mix, unsweetened, prepared 1 5 5 5 5 10 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 11 11 11 8 8 8 8 uid ounce(s) 30 9 106 <.1 uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) 150 133 150 106 150 132 148 270 300 355 355 360 360 380 426 331 372 354 355 354 355 371 321 360 334 366 330 372 368 330 360 360 326 372 329 368 355 354 360 360 330 370 360 360 360 237 237 240 240 237 237 239 236 235 224 224 235 235 237 uid ounce(s) 240 uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) 242 276 221 250 213 248 247 220 240 220 248 105 125 240 100 150 0 146 2 179 156 4 4 189 0 124 160 147 0 170 179 151 0 0 150 152 240 4 144 9 5 78 78 5 5 5 5 129 113 131 104 50 108 uid ounce(s) 240 5 uid ounce(s) 240 uid ounce(s) uid ounce(s) uid ounce(s) 240 240 211 240 uid ounce(s) uid ounce(s) uid ounce(s) 325 325 325 uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) 237 237 237 237 236 236 236 236 150 120 110 110 220 220 220 2 2 2 2 <1 <1 <1 <1 <1 0 0 0 <1 <1 <1 <1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <1 4 4 <1 <1 <1 0 0 <.1 <1 <.1 0 <1 0 2 1 0 0 10 10 10 0 0 0 <.1 13 4 4 21 1 18 0 41 <1 46 40 <1 <1 49 0 32 42 38 0 46 46 38 <1 0 41 39 59 0 39 0 1 6 6 1 1 1 0 33 29 34 26 14 28 0 34 28 29 28 42 40 40 1 1 <1 <1 0 <.1 0.02 0.01 0.04 0 0 0 0 <.1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 <1 0 0 0 0 <1 0 <1 0 0 <1 0 1 1 0 0 5 5 5 0 0 0 0 0 0 0 0 <.1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 0 0 0 0 0 0 0 0 0 4 4 0 0 0 0 <.1 0 <1 <.1 0 <.1 0 1 0 0 0 3 3 3 0 0 0 0 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.26 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2.53 2.53 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.18 1.18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.15 0.15 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.02 0.00 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.04 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.00 0.50 0.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.50 1.50 1.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.50 0.50 0.50 0.01 0.01 0.01 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-45 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 17 17 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 5 5 0 0 0 0 <1 0.02 12 12 13 17 18 13 11 11 14 19 11 11 7 19 11 14 18 2 5 152 152 5 5 10 0 22 5 10 7 10 14 0 20 20 0 0 400 400 400 0 0 5 7 1.43 0.36 0.47 0.81 0.04 0.09 0.07 0.11 0.11 0.19 0.66 0.30 0.26 0.22 0.15 0.07 0.18 0.02 0.12 0.26 0.26 0.12 0.12 0.10 0.00 0.58 0.45 0.52 0.02 0.18 0.46 0.00 1.44 0.00 0.00 0.00 2.70 2.70 2.70 0.05 0.05 0.19 0.05 <1 16 14 15 16 4 4 4 4 4 4 4 4 4 4 0 4 4 5 12 22 22 12 12 7 6 3 5 2 5 140 140 140 7 7 2 5 5 171 138 118 135 7 0 18 4 4 21 0 4 116 4 4 4 70 0 7 4 14 30 0 4 0 110 0 114 128 250 250 128 128 72 160 69 30 50 22 30 50 10 330 70 20 40 600 600 600 88 88 21 47 2 15 14 7 25 75 50 42 17 15 18 21 44 53 26 56 41 35 70 45 37 57 35 35 48 113 36 71 2 5 62 62 5 5 5 20 61 15 7 5 110 31 10 40 30 10 10 220 220 220 7 7 2 7 0.01 0.15 0.11 0.10 0.17 0.36 0.04 0.04 0.00 0.28 0.26 0.18 0.26 0.18 0.37 0.15 0.11 0.26 0.02 0.05 0.50 0.50 0.05 0.05 0.02 0.33 0.30 0.07 0.02 0.20 2.25 2.25 2.25 0.05 0.05 0.09 0.02 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.00 0.00 0.00 0.02 0.00 0.02 0.03 0.01 0.01 0.00 0.00 0.00 0.02 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.04 0.00 0.00 0.00 0.00 0.00 0.03 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.10 0.10 0.05 0.05 0.00 0.04 0.03 0.01 0.02 0.00 0.00 0.00 0.08 0.08 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.12 0.00 0.20 0.20 0.00 0.00 0.00 0.00 0.12 0.32 0.10 0.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 0.00 0.00 0.00 0.00 0.00 0.53 0.37 0.37 0.53 0.53 0.56 0.05 0.00 0.02 0.04 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 0.00 0.00 0.00 0.00 0.05 0.05 0.00 0.00 0.00 0.06 0.00 0.02 0.00 0.04 0.53 0.53 0.53 0.00 0.00 0.02 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.06 0.01 0.07 0.01 0.05 0.60 0.60 0.60 0.03 0.03 0.01 0.00 0.06 0.03 0.05 0.02 0.05 7.00 7.00 7.00 0.00 0.00 0.00 0.09 0.00 0.01 0.02 0.01 0.01 0.70 0.70 0.70 0.00 0.00 0.00 0.00 0 1 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 5 <1 5 5 <1 <1 0 4 0 2 2 4 120 120 120 12 12 2 0 0 0 0 0 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 99 85 13 6 1 42 6 600 60 0 0 60 60 60 0 0 0 0 0 0 <.1 0 0 <.1 0 0 0 0 0 0 0 0 0 0 <1 0 0 0 0 <1 <1 0 0 0 0 0 0 0 0 0 0 0 0 2 2 2 0 0 0 0 1 <1 0 <1 <1 0 <1 0 <1 0 0 0 <1 <1 0 0 <1 0 <1 <1 <1 1 18 18 18 0 0 0 0 h a p p e n d i x h-46 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans da + code 735 1413 33183 1 1879 104 921 107 944 2522 2671 922 5454 111 114 116 117 928 119 beverages continued instant lemon avored tea mix w/sugar, prepared water mineral water, carbonated poland spring water, bottled tap water tonic water fats and oils butter butter unsalted whipped whipped, unsalted butter buds, dry butter substitute fats, cooking beef tallow, semisolid chicken fat household shortening w/vegetable oil lard margarine margarine soft soft, unsalted unsalted whipped spreads 16164 16157 i can t believe it s not butter! -whipped spread promise vegetable oil spread, stick 2681 120 122 124 2693 923 130 128 2700 357 132 133 1764 29654 29617 134 135 136 137 139 942 1765 3666 940 939 941 142 143 oils canola corn olive peanut saf ower sesame soybean w/cottonseed oil soybean, hydrogenated sun ower pam original no stick cooking spray salad dressing blue cheese blue cheese, low calorie caesar creamy, reduced calorie, fat free, cholesterol free, sour cream and/or buttermilk & oil creamy, reduced calorie, sour cream and/or buttermilk & oil french french, low fat italian italian, diet mayonnaise type oil & vinegar ranch ranch, reduced calorie russian russian, low calorie sesame seed thousand island thousand island, low calorie sandwich spreads 138 mayonnaise w/soybean oil h x i d n e p p a 8 8 8 8 8 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 uid ounce(s) 259 236 uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) 237 237 237 244 237 237 237 222 tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) teaspoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) serving(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) 15 15 11 11 2 13 13 13 13 14 14 14 14 9 14 14 14 14 14 14 14 14 14 14 14 0 31 32 30 32 30 31 33 29 30 29 31 30 30 31 33 31 31 31 14 2 3 2 2 0 <.1 0 0 2 2 3 3 1 4 4 0 0 0 0 0 0 0 0 0 10 25 10 24 22 11 18 17 25 12 15 12 21 11 21 12 15 19 2 88 0 0 0 83 108 108 82 82 8 115 115 115 114 101 101 101 101 64 60 90 120 120 119 119 120 120 120 120 120 0 154 32 158 34 48 143 76 86 23 115 140 146 62 151 46 136 115 62 99 <1 0 0 0 0 <1 <1 <.1 <.1 0 0 0 0 0 <1 <1 <1 <.1 <.1 0 0 0 0 0 0 0 0 0 0 0 0 1 2 <1 <1 <1 <1 <1 <1 <1 <1 0 <1 <1 <1 <1 1 <1 <1 <1 22 0 0 0 21 <.1 <.1 <.1 <.1 2 0 0 0 0 <1 <.1 <1 <.1 <.1 0 0 0 0 0 0 0 0 0 0 0 0 2 1 1 6 2 5 10 3 1 7 1 2 2 3 9 3 5 7 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <.1 0 0 0 <1 0 0 0 0 <.1 <.1 0 <.1 <1 <1 <1 0 <.1 0.01 0.00 0.02 0.00 0.00 0.00 0.00 6.13 7.71 5.76 5.76 0.00 6.37 3.81 3.39 4.94 2.23 1.95 1.95 2.12 1.17 1.50 2.50 0.97 1.73 1.82 2.28 0.84 1.93 2.45 2.03 1.77 0.00 3.03 0.82 2.64 0.00 0.00 0.00 0.00 5.00 3.15 2.67 2.67 0.00 5.35 5.72 5.56 5.68 5.05 4.02 5.26 5.17 3.25 1.50 2.00 8.01 3.29 9.98 6.24 10.15 5.40 4.01 5.85 6.28 0.00 3.76 0.57 4.05 0.00 0.00 0.00 0.00 0.43 0.46 0.34 0.34 0.00 0.51 2.68 2.75 1.41 3.58 4.88 3.62 3.53 2.51 2.50 4.00 4.03 7.98 1.35 4.32 1.95 5.67 6.54 5.11 4.95 0.00 8.51 0.78 9.86 0.16 0.21 0.46 0.63 1.76 0.36 1.32 0.14 1.44 2.84 2.32 1.13 2.23 0.20 1.90 1.59 0.23 0.98 2.63 1.92 1.86 0.66 2.65 4.62 3.85 1.79 3.61 0.29 3.64 2.46 1.98 2.40 6.56 1.64 3.80 0.51 5.29 7.52 8.92 2.89 9.00 0.75 7.68 5.68 0.82 0 0 0 0 2.20 0.04 1.64 2.70 5.89 0.04 0 0 0 0 12 12 9 9 0 13 13 13 13 11 11 11 11 7 7 10 14 14 14 14 14 14 14 14 14 0 16 2 17 1 4 14 4 8 2 10 16 16 6 16 1 14 11 4 11 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-47 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 32 32 25 25 0 14 11 0 12 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 <1 1 0 0 0 0 0 2 8 0 1 <1 6 2 0 8 <1 5 5 0.05 5 49 8 0.03 33 2 4.74 2 4 4 3 3 0 0 0 0 0 4 4 4 2 2 10 10 0 0 <1 0 0 0 0 0 0 0 25 28 7 12 2 7 4 2 3 4 0 4 5 6 6 6 5 5 2 0.00 0.02 0.00 0.02 0.00 0.00 0.02 0.02 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.18 0.18 0.00 0.00 0.09 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.06 0.16 0.05 0.08 0.04 0.25 0.28 0.19 0.20 0.06 0.00 0.03 0.01 0.18 0.20 0.18 0.37 0.28 0 2 2.37 0 <1 <1 <1 <1 0 0 0 0 0 <1 <1 <1 <1 <1 0 0 0 0 0 0 0 0 0 0 2 1 2 1 2 3 1 1 1 0 1 1 1 0 0 2 2 0.07 <1 0 0 0 0 4 4 3 3 2 0 0 0 0 6 5 5 4 3 4 9 0 0 <1 0 0 0 0 0 0 0 11 2 9 43 11 21 35 14 26 3 2 8 8 48 51 48 33 62 5 2 2 4.74 10 86 2 94 1 70 0 0 0 0 133 152 4 <1 97 70 90 0 0 <1 0 0 0 0 0 0 0 335 384 323 320 307 261 262 486 410 209 <1 354 414 266 283 306 269 254 0.00 0.00 0 0.24 0.01 0.01 0.01 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.08 0.08 0.03 0.06 0.01 0.09 0.07 0.04 0.06 0.05 0.00 0.01 0.02 0.13 0.03 0.03 0.08 0.06 78 0.02 0 0 0 0 0 103 103 78 0 0 0 0 0 115 103 103 115 0 0 0 0 0 0 0 0 0 0 21 0 7 9 1 <1 19 0 5 1 1 3 5 12 0.00 0.00 0.04 0.09 0.01 0.00 0.00 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.65 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.57 0.00 0.35 0.35 0.26 0.26 0.00 0.35 0.35 0.08 1.27 0.99 1.23 1.80 0.45 0.00 2.33 1.94 1.94 2.12 4.64 0.19 1.65 1.10 0.00 1.84 0.08 1.57 0.00 0.00 0 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.03 0.00 0.00 0.00 0 0.00 0.01 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.02 0.01 0.00 0.00 0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.00 0.21 0.02 0.01 0.01 0.00 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.45 0.01 0.72 1.56 0.10 1.47 0.06 0.61 1.44 1.85 0.73 1.02 0.13 1.53 1.25 0.31 0.00 0.02 0.02 0.01 0.00 0.01 0.00 0.00 0.01 0.02 0.00 0.00 0.02 0.01 0.01 0.06 0.15 0.00 0.00 0.00 0.00 0.00 0.01 0.18 0.00 0.00 0.13 0.13 0.01 0.00 0.02 0.02 0.02 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.72 0.00 0.00 0.08 0 0 0 0 0 <1 <1 <1 <1 <1 0 0 0 0 <1 <1 <1 <1 <.1 0 0 0 0 0 0 0 0 0 9 1 1 1 4 0 1 0 0 2 0 <1 <1 3 1 0 0 0 1 <1 0 0 0 0 0 0 0 0 0 0 0 0 0 <.1 <.1 <.1 <.1 <.1 1 1 0 0 0 0 0 0 0 0 0 0 1 <.1 0 0 <1 0 0 0 0 0 0 <.1 <1 2 2 0 0 0 0 0 0 0 0 0 <.1 <.1 <.1 <.1 0 0 0 0 0 <.1 <.1 <.1 <.1 <.1 0 0 0 0 0 0 0 0 0 0 <.1 <.1 <.1 0 <.1 <.1 0 0 0 <.1 0 <.1 <.1 <.1 <.1 0 0 0 <.1 <1 0 0 0 0 <1 <1 <1 <.1 <.1 <.1 0 0 0 0 0 0 0 0 0 0 0 0 0 <1 0 1 1 2 <1 0 <1 1 <1 <1 0 <1 h a p p e n d i x h-48 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 2708 140 141 4799 1786 1785 33375 1701 33378 1787 1784 4674 4934 1780 1790 4679 1781 4673 1783 1788 1789 4689 33399 1782 4694 4695 4698 4699 4702 4705 4760 4771 17291 536 13697 2616 548 23054 23278 545 4800 555 4780 559 563 561 1760 13029 1759 3148 29676 4795 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fats and oils continued mayonnaise w/soybean & saf ower oils mayonnaise, low calorie tartar sauce sweets butterscotch or caramel topping candy almond joy candy bar bit-o-honey candy butterscotch candy chewing gum, stick chocolate fudge w/nuts, prepared jelly beans kit kat wafer bar krackel candy bar licorice life savers candy lollipop m & ms peanut chocolate candy, small bag m & ms plain chocolate candy, small bag milk chocolate bar milky way bar peanut brittle reese s peanut butter cups reese s pieces candy, small bag semisweet chocolate candy, made w/butter snickers bar special dark chocolate bar starburst fruit chews, original fruits taffy three musketeers bar twix caramel cookie bars york peppermint pattie frosting, icing chocolate frosting, ready to eat creamy vanilla frosting, ready to eat dec-a-cake variety pack candy decoration white icing gelatin gelatin snack, all avors mixed fruit gelatin mix, sugar free, low calorie, prepared honey jams, jellies jams, jellies, preserves, all avors jams, jellies, preserves, all avors, low sugar marshmallows marshmallow cream topping molasses popsicle or ice pop sugar brown, packed powdered, sifted white granulated sugar substitute equal sweetener, packet splenda granular no calorie sweetener sweet n low sugar substitute, packet syrup chocolate maple pancake 1 1 2 2 1 6 2 1 2 15 1 1 4 1 1 1 1 1 1 11 2 2 1 1 2 1 1 1 3 1 2 1 2 2 1 2 1 1 2 1 1 1 4 2 1 1 1 1 3 1 1 1 1 2 1 4 1 4 0 10 9 98.94 37 144 0.15 <.1 <1 0.37 3 4 13 103 1 tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) item(s) item(s) piece(s) item(s) piece(s) item(s) item(s) item(s) piece(s) item(s) item(s) item(s) item(s) item(s) item(s) ounce(s) piece(s) item(s) ounce(s) item(s) item(s) package piece(s) item(s) item(s) item(s) tablespoon(s) tablespoon(s) teaspoon(s) tablespoon(s) item(s) 14 16 28 41 49 40 12 3 38 43 42 41 44 2 28 49 48 91 58 43 45 46 14 59 41 59 45 60 58 42 28 28 4 40 99 5 2 1 <.1 3 3 1 1 7 1 1 1 4 <1 1 1 <.1 3 <1 4 2 4 2 4 5 4 3 97 cup(s) tablespoon(s) 121 4 21 tablespoon(s) tablespoon(s) item(s) tablespoon(s) tablespoon(s) item(s) teaspoon(s) cup(s) teaspoon(s) item(s) teaspoon(s) item(s) tablespoon(s) cup(s) cup(s) 20 18 29 28 20 59 5 33 4 1 1 1 38 80 80 <.1 <.1 5 6 4 47 <.1 <.1 <.1 <.1 <.1 12 26 30 27 29 34 11 2 26 40 27 26 34 2 28 30 34 53 41 30 25 26 9 35 24 48 41 46 37 34 18 19 3 32 17 0 17 14 6 23 22 15 11 4 33 4 1 1 1 24 54 49 240 170 47 7 175 159 220 220 147 8 108 250 240 483 270 206 250 230 68 280 220 240 169 260 280 170 112 118 15 163 70 10 64 56 25 92 91 58 42 17 130 15 4 2 4 105 209 187 2 1 <.1 0 2 0 3 3 1 0 0 5 2 8 2 3 5 6 1 4 2 0 <.1 2 3 1 <1 0 0 <1 1 1 <.1 <.1 <.1 1 <1 0 0 0 0 0 <.1 0 0 1 0 0 0 0 <.1 <1 2 0 0 <.1 1 <.1 1 1 1 0 0 2 1 2 1 1 1 1 1 1 3 0 0 1 1 1 <1 <.1 0 0 0 0 <.1 <1 <1 <.1 <.1 0 0 0 0 0 0 0 0 1 0 1 10.95 3 14 1.18 0.53 2.14 1.79 0.72 4.13 7.59 1.70 7.57 <.1 0.05 0.01 0.00 13 3 <1 <.1 7 <.1 11 11 1 <.1 0 13 10 28 10 8 14 11 4 14 13 5 1 8 14 3 5 5 1 4 0 0 0 <.1 <.1 <.1 <.1 <.1 0 0 <.1 0 0 0 0 <1 <1 0 9.00 2.00 0.25 0.00 2.29 0.00 7.00 6.00 0.18 0.00 0.00 3.63 0 0.10 0.00 1.41 0.00 3.53 3.94 0.07 0.00 0.74 20 0.01 0.00 2.81 0.00 0.34 0.37 0.00 0.00 5.00 5.42 2.07 6.00 16.69 5.00 1.76 5.00 7.00 2.49 5.00 8.00 1.00 0.92 4.50 5.00 2.00 1.55 0.84 0.00 0.86 3.30 7.20 3.50 3.43 6.17 0.97 1.41 6.13 4.59 2.10 0.43 2.59 7.75 1.32 2.54 1.37 2.07 0.30 0.63 0.35 1.94 2.34 0.46 0.13 2.89 0.41 1.83 0.05 0.27 0.49 0.12 0.60 2.24 1.19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.02 0.02 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.19 0.03 0.00 0.01 0.02 0.02 0.01 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.11 0.05 0.00 0.02 0.01 0.01 0.01 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.01 0.08 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-49 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 8.14 4 11 <1 3 0.00 1 0 5 0 3 3 0 0 0 5 5 22 5 5 3 0 3 5 3 0 4 5 5 0 0 0 0 <1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2.48 <.1 6 22 20 <1 0 21 1 40 60 3 <1 0 40 40 228 60 11 20 40 5 40 0 10 1 20 40 0 2 1 0 5 0 0 1 4 2 1 1 41 0 4 <1 <.1 0 10 0 5 54 2 0.06 0.00 0.21 0.08 0.36 0.00 0.00 0.75 0.06 0.36 0.37 0.13 0.04 0.00 0.36 0.36 0.83 0.18 0.52 0.36 0.00 0.44 0.36 0.72 0.18 0.03 0.36 0.36 0.36 0.40 0.04 0.00 0.02 0.00 0.00 0.09 0.10 0.05 0.07 0.06 0.94 0.00 0.09 0.01 0.00 0.00 0.18 0.00 0.79 0.96 0.02 0.13 <.1 1 4.69 2 10 78.38 80 200 0.01 0.02 0.05 11.59 0 0 0.00 0.00 3.04 0.32 0.97 0 0.00 0.00 0 0.00 0.01 0.07 0.00 0.08 1.1 0 2 34 143 0.08 0.00 0.04 0.02 0.01 3 33 85 <1 0 21 1 16 3 36 20 61 20 18 40 20 16 42 46 1 <1 18 18 25 6 <1 0 <1 1 1 1 1 48 1 1 0 0 0 0 24 11 2 138 <1 <.1 68 16 126 169 28 0 171 127 399 140 71 233 182 52 136 1 2 80 117 71 55 10 7 0 0 11 15 19 1 1 293 2 16 1 <.1 0 84 163 12 70 0 47 <.1 16 21 25 80 109 1 11 25 30 92 95 189 140 90 2 140 0 0 40 110 115 10 51 52 15 92 40 50 1 6 <1 23 23 7 7 2 <1 0 0 <1 0 27 7 66 11 0 3 0 14 0 8 0 0 0 0 15 15 20 15 17 7 25 <1 15 0 14 15 0 0 0 0 0 0 0 0.40 0.00 0.00 0.54 0.02 0.52 0.07 1.13 0.46 1.00 0.41 0.37 0.82 0.35 0.23 1.38 0.60 0.00 0.02 0.33 0.45 0.31 0.08 0.02 0.00 0.05 0.02 0.00 0.00 0.03 0.00 0.07 0.01 0.00 0.00 0.03 0.03 0.06 0.02 0.06 0.11 0.04 0.01 0.03 0.01 0.00 0.00 0.02 0.09 0.01 0.00 0.00 0.00 0.01 0.00 0.10 0.00 0.08 0.08 0.00 0.00 0.04 0.00 0.23 0.02 0.00 0.00 0.24 0.00 0.00 0.12 0.00 1.07 0.04 0.00 0.00 0 0.00 0.00 0.03 0.00 0.05 0.00 0.07 1.60 0.04 1.09 0.44 0.43 0.33 0.07 0.26 0.07 0.02 0.08 0.07 0.01 0.07 0.03 0.00 0.01 0.03 0.13 0.04 0.00 0.08 0.01 0.11 0.15 0.20 1.13 2.08 1.31 0.06 1.60 0.16 0.00 0.01 0.20 0.69 0.34 0.03 0.06 0.00 0.01 0.10 0.03 0.03 0.07 0.03 0.01 0.05 0.01 0.00 0.00 0.01 0.02 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.03 0.00 0.01 1 0 0 6 0 60 0 17 3 11 6 20 25 13 <1 23 1 0 0 0 14 2 <1 2 0 <1 0.01 0.00 0.00 0.00 0.02 0.01 0.00 2.20 0.02 0.01 0.01 0.06 0.01 0.01 0.00 0.00 0.00 0.00 0.27 3.33 0.06 0.76 0 0 0 0 0 0 0 0 0 0 0 0 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.02 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.02 0.00 0.02 0.01 0.01 0.03 0.02 0.02 0.19 0.00 0.00 0.00 0.00 0.00 0.20 0.00 0.12 0.02 0.01 0.01 0.00 0.00 0.13 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 <1 <1 0 0 <.1 0 0 0 0 1 0 0 0 0 <1 <1 0 0 0 <.1 0 0 0 0 0 0 1 1 2 1 0 0 0 0 1 0 30 0 1 1 0 0 0 0 <.1 0 0 <1 1.76 4.93 0 0 0 0 0 0 0 0 1 0 <.1 0 0 0.03 0 <.1 0.22 <.1 0 0 <.1 0 <.1 0 <.1 <1 <1 <1 <.1 <.1 <.1 0 <.1 0 0 <.1 <1 <1 <.1 0 0 0 0 0.00 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <.1 <.1 1 <1 2 0 1 2 1 3 1 2 1 <1 3 1 <1 2 1 <1 <.1 <1 <1 1 4 0 <.1 <1 <.1 0 0 1 <1 0 h a p p e n d i x h-50 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 807 1171 729 683 1611 8552 34959 808 809 11720 818 730 35417 1172 819 1173 1174 810 8553 8556 811 812 1175 1176 1706 11729 1177 1178 1179 1180 34949 4949 1181 1182 11733 1067 813 1183 1068 35497 1184 1185 1186 814 2747 1187 815 816 817 1189 1190 1191 1192 11723 2722 11724 1193 822 30189 30190 1194 820 11725 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans spices, condiments, sauces spices allspice, ground anise seeds baker s yeast active baking powder, double acting, w/phosphate baking soda basil basil, fresh basil, ground bay leaf betel leaves black pepper brewer s yeast capers caraway seeds cayenne pepper celery seeds chervil, dried chili powder chives, chopped cilantro cinnamon, ground cloves, ground coriander leaf, dried coriander seeds cornstarch cumin, ground cumin seeds curry powder dill seeds dill weed, dried dill weed, fresh fennel leaves, fresh fennel seeds fenugreek seeds garam masala, powder garlic clove garlic powder ginger, ground ginger root leeks, bulb & lower leaf, freeze-dried mace, ground marjoram, dried mustard seeds, yellow nutmeg, ground onion akes, dehydrated onion powder oregano, ground paprika parsley, dried poppy seeds poultry seasoning pumpkin pie spice, powder rosemary, dried rosemary, fresh saffron powder sage sage, ground salt, table salt substitute salt substitute, seasoned savory, ground sesame seed kernels, toasted sorrel 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5 1 1 1 1 1 1 1 2 1 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 1 4 1 4 1 1 1 teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) piece(s) teaspoon(s) teaspoon(s) ounce(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) tablespoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) piece(s) teaspoon(s) teaspoon(s) teaspoon(s) ounce(s) item(s) teaspoon(s) teaspoon(s) teaspoon(s) cup(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) ounce(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) tablespoon(s) 2 2 4 5 5 1 1 1 1 28 2 3 4 2 2 2 1 3 1 2 2 2 1 2 8 5 2 2 2 1 1 1 2 4 28 3 3 2 4 1 2 1 3 2 2 2 2 2 0 3 2 2 1 1 1 28 1 2 1 1 1 3 9 <1 <1 <1 <1 <.1 1 <1 <.1 <.1 <1 <1 <1 <1 <1 <.1 <1 1 1 <1 <1 <.1 <1 1 <1 <1 <1 <.1 1 1 <1 <1 2 <1 <1 3 <.1 <1 <.1 <1 <1 <.1 <1 <1 <1 <.1 <1 <1 <1 <1 <1 <.1 <.1 <.1 <1 <1 5 7 12 2 0 <1 <1 4 2 17 5 8 2 7 6 8 1 8 <1 <1 6 7 2 5 30 11 8 7 6 3 <1 <1 7 12 107 4 9 6 3 3 8 2 15 12 6 7 5 6 1 15 5 6 4 1 2 34 2 0 <.1 1 4 15 2 <1 <1 2 <.1 0 <.1 <.1 <1 <.1 2 <1 1 0 <1 <1 <1 <1 <1 <.1 <.1 <.1 <1 <1 <1 <.1 <1 <1 <1 <1 <1 <.1 <.1 <1 1 4 <1 <1 <1 <.1 <1 <1 <.1 1 <1 <1 <1 <1 <1 <.1 1 <1 <.1 <.1 <.1 <.1 1 <.1 0 0 <.1 <.1 <1 <1 1 1 2 1 0 <.1 <.1 1 <1 2 1 1 0 1 1 1 <1 1 <.1 <.1 2 1 <1 1 7 1 1 1 1 1 <.1 <.1 1 2 13 1 2 1 1 1 1 <1 1 1 1 2 1 1 <1 1 1 1 1 <1 <1 4 <1 0 <.1 <1 1 1 <1 <1 <1 1 <.1 0 <.1 <.1 1 <1 0 1 1 0 1 <1 <1 <.1 1 <.1 <.1 1 1 <.1 1 <.1 1 <1 1 <1 <1 <.1 0 1 1 0 <.1 <1 <1 <.1 <.1 <1 <1 <1 <1 <1 <1 1 1 <.1 <1 <1 <1 1 <.1 <.1 0 <1 0 0 0 1 <1 <.1 <1 <1 <1 0 0 <.1 <.1 <.1 <.1 <.1 <.1 0 0 <1 <1 1 <.1 <1 <.1 <.1 <.1 <1 <.1 <1 <.1 <1 <1 <1 <1 <.1 <.1 <.1 <1 <1 4 <.1 <.1 <1 <.1 <.1 1 <.1 1 1 <.1 <.1 <1 <1 <.1 1 <1 <1 <1 <.1 <.1 1 <.1 0 0 <.1 <.1 1 <.1 0.05 0.01 0.02 0.00 0.00 0.00 0.00 0.00 0.01 0.02 0.00 0.00 0.01 0.06 0.04 0.00 0.08 0.00 0.00 0.01 0.11 0.00 0.02 0.00 0.03 0.04 0.02 0.00 0.00 0.00 0.01 0.05 0.00 0.00 0.03 0.01 0.00 0.16 0.00 0.05 0.57 0.00 0.00 0.04 0.04 0.00 0.14 0.05 0.11 0.09 0.02 0.01 0.05 0.00 0.00 0.00 0.05 0.18 0.00 0.01 0.21 0.10 0.00 0.00 0.00 0.00 0.01 0.01 0.02 0.00 0.00 0.15 0.05 0.32 0.01 0.09 0.00 0.00 0.01 0.03 0.01 0.24 0.00 0.29 0.11 0.20 0.01 0.01 0.00 0.20 0.00 0.00 0.02 0.01 0.00 0.19 0.01 0.65 0.07 0.00 0.00 0.01 0.03 0.01 0.18 0.02 0.02 0.04 0.01 0.00 0.01 0.00 0.00 0.49 0.04 0.07 0.00 0.00 0.00 0.00 0.00 0.03 0.01 0.02 0.00 0.00 0.07 0.15 0.07 0.01 0.19 0.00 0.00 0.01 0.15 0.00 0.03 0.00 0.07 0.05 0.02 0.00 0.00 0.00 0.03 0.01 0.01 0.02 0.01 0.01 0.07 0.03 0.18 0.01 0.00 0.01 0.08 0.17 0.00 0.86 0.03 0.01 0.03 0.01 0.01 0.01 0.00 0.00 0.57 0 0 0 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-51 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 13 14 3 339 0 1 1 30 5 110 9 6 0 14 3 35 8 7 1 1 28 14 7 13 <1 20 20 10 32 18 2 1 24 7 215 5 2 2 1 3 4 12 17 4 4 8 24 4 4 41 15 12 15 2 1 170 12 <1 7 0 30 4 0.13 0.78 0.66 0.52 0.00 0.03 0.59 0.26 2.29 0.61 0.47 0.00 0.34 0.14 0.90 0.19 0.37 0.02 0.03 0.88 0.18 0.25 0.29 0.04 1.39 0.59 0.34 0.49 0.03 0.37 1.24 9.25 0.05 0.08 0.21 0.02 0.06 0.24 0.50 0.33 0.07 0.03 0.05 0.66 0.50 0.29 0.26 0.53 0.34 0.35 0.05 0.08 0.20 0.00 0.00 0 0.53 0.21 3 4 4 2 0 1 <1 6 1 4 6 5 3 9 1 4 <1 <1 1 6 4 6 <1 8 5 5 5 1 8 7 94 1 2 3 2 1 3 2 10 4 2 3 4 4 1 9 3 2 3 1 2 45 3 <.1 <.1 476 5 9 20 30 80 <1 0 4 2 48 3 156 26 51 28 36 28 28 50 3 8 12 23 27 23 <1 44 38 31 25 33 7 4 34 28 411 12 31 24 17 19 8 9 23 8 27 20 25 49 11 20 10 11 11 5 12 110 7 <1 604 <1 15 11 1 <1 2 363 1259 <.1 <.1 <1 <1 2 1 3 140 <1 1 3 <1 26 <.1 1 1 5 1 1 1 5 4 1 <1 2 1 <.1 2 2 28 1 1 1 1 <1 1 <1 <1 <1 <1 1 <1 1 1 1 <1 1 1 <1 1 1 <.1 581 <.1 <1 1 <1 0.02 0.11 0.26 0.00 0.00 0.01 0.00 0.08 0.02 0.03 0.21 0.12 0.04 0.14 0.05 0.07 0.01 0.00 0.05 0.02 0.03 0.08 0.00 0.10 0.08 0.11 0.03 0.01 0.07 0.09 1.07 0.03 0.07 0.08 0.01 0.01 0.04 0.02 0.19 0.05 0.03 0.05 0.07 0.09 0.01 0.29 0.05 0.04 0.04 0.01 0.01 0.48 0.03 0.00 0 0.06 0.28 1 <1 0 0 0 2 7 2 <1 0 0 <1 37 <.1 2 39 2 <1 1 2 0 0 1 1 <.1 3 <1 <1 0 0 <1 0 <1 1 2 <.1 <1 <.1 0 5 55 2 0 2 <1 2 1 <1 2 0 0 4 <.1 0.00 0.01 0.09 0.00 0.00 0.00 0.00 0.00 0.00 0.04 0.00 0.42 0.01 0.01 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.01 0.01 0.01 0.00 0.00 0.00 0.01 0.01 0.10 0.01 0.01 0.00 0.00 0.01 0.01 0.00 0.02 0.01 0.01 0.01 0.01 0.01 0.00 0.02 0.00 0.00 0.01 0.00 0.00 0.03 0.01 0.00 0.01 0.03 0.00 0.00 0.00 0.10 0.02 0.05 0.54 0.02 0.76 0.02 0.18 0.00 0.07 0.44 0.00 0.02 0.32 0.01 0.01 0.10 0.00 0.00 0.01 0.28 0.63 0.02 0.03 0.03 0.02 0.05 0.00 0.01 0.00 0.01 0.22 0.00 0.00 0.00 0.00 0.00 0.00 0.07 0.01 0.11 0.01 0.02 0.01 0.00 0.02 0.00 0.00 0.00 0.01 0.01 0.01 0.00 0.01 0.01 0.01 0.00 0.00 0.00 0.01 0.01 0.09 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.01 0.00 0.00 0.00 0.00 0.04 0.00 0.00 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.05 0.06 1.59 0.00 0.00 0.01 0.01 0.10 0.01 0.20 0.02 1.00 0.08 0.16 0.06 0.03 0.21 0.01 0.02 0.03 0.03 0.06 0.04 0.00 0.10 0.07 0.06 0.03 0.02 0.01 0.12 0.06 0.71 0.02 0.02 0.09 0.03 0.03 0.02 0.02 0.26 0.03 0.02 0.01 0.09 0.32 0.02 0.03 0.04 0.04 0.01 0.01 0.01 0.04 0.00 0.06 0.15 0.00 0.01 0.06 0.00 0.00 0.00 0.00 0.03 0.01 0.01 0.07 0.01 0.04 0.02 0.01 0.10 0.00 0.00 0.01 0.01 0.00 0.00 0.01 0.02 0.01 0.02 0.00 0.00 0.01 0.02 0.04 0.08 0.02 0.01 0.01 0.00 0.01 0.01 0.00 0.03 0.03 0.02 0.08 0.00 0.01 0.02 0.01 0.02 0.00 0.01 0.02 0.00 0.03 0.00 1 <1 94 0 0 1 <1 4 1 <1 104 <1 2 <1 2 3 1 1 1 2 2 0 0 <1 3 <1 2 2 2 0 <.1 <.1 1 <1 3 1 2 3 2 3 3 4 2 1 2 2 1 4 1 1 2 0 0 3 1 <1 <.1 0 0 <1 1 <1 1 <1 0 0 <1 1 <1 <1 2 1 1 1 2 3 <1 0 <1 <1 <1 1 <1 <1 <1 0 1 1 <1 <1 1 <1 <1 <.1 <.1 1 <1 1 1 <1 <.1 <1 <1 1 <1 1 <1 0 0 1 0 0 0 <.1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 <.1 <1 1 <.1 <.1 <.1 <.1 <.1 <.1 <.1 0 <1 <1 <1 <1 <1 <.1 <.1 <.1 <1 <1 <1 <1 <1 <1 <1 0 0 <1 <1 1 1 <.1 <.1 <.1 <.1 4 <.1 <.1 <.1 <.1 <.1 <.1 <.1 <1 <1 <.1 <.1 <.1 <.1 <.1 <.1 h a p p e n d i x h-52 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 11721 35498 11726 11727 1195 11728 821 1196 11995 1188 674 703 1641 140 138 1682 700 706 141 685 834 32123 32122 29688 16670 29689 1655 347 841 839 1613 25294 728 1654 30853 727 1673 15439 16652 25224 25227 9516 16796 177 30233 16651 475 30330 215 30239 25093 28020 218 30240 25119 25099 1062 1896 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans spices, condiments, sauces continued spearmint sweet green peppers, freeze-dried tamarind leaves tarragon tarragon, ground thyme, fresh thyme, ground turmeric, ground wasabi white pepper condiments catsup or ketchup dill pickle horseradish sauce, prepared mayonnaise, low calorie mayonnaise w/soybean oil mustard, brown mustard, yellow sweet pickle relish tartar sauce sauces barbecue sauce cheese sauce chili enchilada sauce, green chili enchilada sauce, red hoisin sauce mole poblano sauce oyster sauce pepper sauce or tabasco salsa soy sauce sweet & sour sauce teriyaki sauce tomato sauce white sauce, medium worcestershire sauce vinegar balsamic cider distilled tarragon mixed foods, soups, sandwiches mixed dishes almond chicken barbecued chicken bean burrito beef & vegetable fajita beef or pork egg roll beef stew w/vegetables, prepared beef stroganoff w/noodles cashew chicken cheese pizza cheese quesadilla chicken & noodles, prepared chicken & vegetables w/broccoli, onion, bamboo shoots in soy based sauce chicken cacciatore chicken fried turkey steak chicken pot pie chicken teriyaki chicken waldorf salad chili con carne coleslaw combination pizza, w/meat & vegetables 1 1 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 1 4 2 2 1 1 2 1 1 2 1 2 1 1 2 1 4 1 1 1 1 1 1 2 1 1 2 1 1 1 2 1 1 1 1 3 1 1 1 2 3 4 3 4 2 teaspoon(s) cup(s) ounce(s) ounce(s) teaspoon(s) teaspoon(s) teaspoon(s) teaspoon(s) tablespoon(s) teaspoon(s) tablespoon(s) ounce(s) teaspoon(s) tablespoon(s) tablespoon(s) teaspoon(s) teaspoon(s) tablespoon(s) tablespoon(s) tablespoon(s) cup(s) tablespoon(s) tablespoon(s) tablespoon(s) cup(s) tablespoon(s) teaspoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) cup(s) cup(s) teaspoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) cup(s) piece(s) item(s) item(s) item(s) cup(s) cup(s) cup(s) slice(s) item(s) cup(s) cup(s) cup(s) ounce(s) cup(s) cup(s) cup(s) cup(s) cup(s) slice(s) 2 2 28 28 2 1 1 2 14 2 15 28 5 16 14 5 5 15 28 31 70 57 32 16 133 16 5 16 18 39 18 112 63 6 15 15 15 16 242 177 149 223 128 245 256 242 126 54 240 162 230 85 252 244 100 215 90 158 2 <.1 <1 1 <1 <1 11 <1 11 26 3 10 2 4 4 9 9 25 49 53 24 7 103 13 5 14 13 30 12 100 47 4 14 14 186 100 82 144 85 201 190 131 60 19 170 112 166 48 154 163 68 175 73 75 1 5 33 14 5 1 4 8 11 7 14 5 10 37 99 5 3 20 144 23 121 15 27 35 155 8 1 4 10 37 15 46 92 4 10 2 2 0 280 325 327 397 227 220 343 644 281 183 365 287 266 122 542 339 178 197 62 368 <.1 <1 2 1 <1 <.1 <1 <1 1 <1 <1 <1 <1 <.1 <1 <1 <1 <.1 <1 1 5 1 1 1 5 <1 <.1 <1 1 <.1 1 2 2 0 0 0 0 0 22 27 17 23 10 16 20 43 15 6 22 22 28 13 23 51 14 14 1 26 <1 1 5 2 1 <1 1 1 2 2 4 1 <1 3 1 <1 <1 5 4 4 5 3 5 7 11 2 <.1 1 2 9 3 8 6 1 2 1 1 0 16 15 33 35 19 15 23 17 41 18 26 6 5 12 42 13 6 21 11 43 <1 <1 0 0 <1 <1 1 <1 <1 1 <1 <1 <.1 0 0 <.1 <1 <1 <.1 <1 <1 1 2 <1 2 <.1 <.1 <1 0 <.1 <.1 2 <1 0 0 0 0 0 3 <1 6 3 1 3 2 3 0 1 1 1 1 1 3 1 1 7 1 5 <.1 <.1 1 <1 <1 <.1 <1 <1 <.1 <.1 <.1 <.1 1 3 11 <1 <1 <.1 14 1 9 <1 1 1 11 <.1 <.1 <.1 <.1 <.1 0 1 7 0 0 0 0 0 15 17 15 18 12 11 19 46 6 10 18 19 14 2 31 7 11 7 2 11 0.00 0.01 0.03 0.00 0.04 0.07 0.02 0.01 0.01 0.59 0.53 1.64 0.01 0.01 2.14 0.08 4.19 0.04 0.08 0.09 2.67 0.01 0.01 0.00 0.00 0.00 0.00 0.18 1.78 0.00 0.00 0.00 0.00 0.00 1.91 4.63 8.30 5.50 2.88 4.40 7.37 7.75 3.08 3.49 5.10 5.13 3.98 0.59 9.79 1.78 1.76 2.55 0.35 3.07 0.00 0.00 0.01 0.00 0.01 0.04 0.02 0.01 0.00 0.28 0.72 2.70 0.11 0.03 4.13 0.24 2.67 0.04 0.05 0.15 5.15 0.01 0.00 0.00 0.00 0.00 0.00 0.29 2.78 0.00 0.00 0.00 0.00 0.00 0.01 0.03 0.06 0.00 0.02 0.05 0.01 0.04 0.02 0.04 1.70 5.89 0.03 0.02 7.57 0.21 1.81 0.13 0.43 0.27 2.91 0.01 0.02 0.02 0.01 0.00 0.00 0.72 1.79 0.00 0.00 0.00 0.00 0.00 0.04 0 0 0 0 0 0 0 0 0 6.07 6.78 4.73 7.53 5.96 4.50 5.62 20.83 1.98 3.42 7.10 7.65 5.78 0.37 12.52 2.03 3.18 2.83 0.64 5.09 5.62 0 3.71 0 0.85 3.45 2.64 0.50 4.47 14.47 0.98 2.16 3.90 4.68 3.11 0.78 7.03 1.71 5.05 0.54 1.22 1.83 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-53 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 0 0 0 0 0 0 0 0 0 0 0 2 4 5 0 0 0 11 0 20 0 0 <1 1 0 0 0 0 0 0 0 4 0 0 0 0 0 40 120 38 45 74 71 74 96 19 13 103 84 103 27 69 157 42 27 7 41 4 2 85 48 18 3 26 4 13 6 3 3 5 <.1 2 6 4 <1 6 6 128 5 7 5 37 5 1 5 3 5 5 21 74 6 0 1 1 0 69 26 331 84 30 29 70 74 233 132 26 22 45 69 64 52 20 43 41 202 0.23 0.17 1.48 0.52 0.14 1.73 0.91 0.11 0.34 0.08 0.15 0.00 0.00 0.07 0.09 0.09 0.13 0.21 0.28 0.15 0.36 1.05 0.16 1.51 0.03 0.06 0.16 0.36 0.20 0.31 1.08 0.21 0.30 0.00 0.09 0.09 0.00 1.97 1.64 2.95 3.74 1.66 2.90 3.26 2.92 1.16 1.21 2.20 1.38 2.21 1.34 3.38 3.27 0.78 3.16 0.53 3.07 1 3 20 14 6 1 3 4 2 3 3 1 <.1 <1 1 2 1 1 6 6 9 11 4 57 1 1 2 6 1 11 19 9 1 3 0 60 31 45 37 20 37 94 32 13 29 37 19 38 67 24 50 9 36 9 51 128 48 5 11 56 2 57 33 7 2 5 7 8 4 10 54 21 126 231 19 283 9 6 34 32 8 41 431 98 45 15 2 0 549 387 384 476 248 613 393 640 219 77 149 344 444 197 393 589 197 646 163 357 1 3 3 1 <.1 1 1 <1 167 363 15 80 78 68 56 122 200 255 578 62 114 258 305 437 32 69 1029 98 690 199 221 56 0 <1 <1 0 526 477 514 757 547 292 818 1355 672 230 600 962 451 139 651 3209 246 865 21 765 0.02 0.04 0.17 0.06 0.01 0.09 0.10 0.03 0.04 0.04 0.01 0.02 0.02 0.02 0.03 0.02 0.05 0.06 0.68 0.11 0.15 0.05 0.95 0.01 0.01 0.04 0.07 0.01 0.02 0.30 0.26 0.01 0.00 0.00 1.62 2.69 1.92 3.51 0.91 3.66 2.24 1.63 0.64 1.70 2.01 1.08 1.93 3.75 1.13 2.44 0.18 2.23 4 3 3 2 3 0 0 7 3 0 12 0 <1 1 <1 56 0 0 4 5 0 0 0 48 0 0 0 0 69 119 147 53 5 607 21 25 48 117 0.00 0.02 0.07 0.04 0.00 0.00 0.01 0.00 0.02 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.00 0.03 0.02 0.00 0.07 0.00 0.00 0.01 0.01 0.00 0.01 0.05 0.04 0.00 0.00 0.00 0.09 0.07 0.24 0.39 0.32 0.15 0.21 0.23 0.37 0.13 0.05 0.08 0.10 0.15 0.40 0.15 0.04 0.13 0.06 0.43 0.06 0.10 0.10 0.22 0.03 0.03 0.32 0.72 0.09 0.01 0.06 0.97 0.01 0.00 0.00 0.04 1.72 0.00 0.19 0.00 0.00 0.39 0.00 0.00 0.00 4.11 0.01 0.01 0.80 1.28 0.51 1.25 4.11 0.43 1.12 0.00 0.00 1.06 0.59 0.62 0.02 0.00 0.02 0.03 0.02 0.00 0.01 0.01 0.01 0.00 0.07 0.01 0.01 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.08 0.02 0.22 0.03 0.09 0.02 0.00 0.01 0.02 0.01 0.01 0.05 0.12 0.01 0.00 0.00 0.20 0.37 0.29 0.30 0.25 0.17 0.31 0.22 0.33 0.14 0.17 0.17 0.21 0.18 0.40 0.37 0.10 0.23 0.06 0.35 0.02 0.12 1.16 0.14 0.01 0.07 0.11 0.07 0.01 0.23 0.02 0.00 0.00 0.00 0.01 0.02 0.03 0.01 0.28 0.02 0.63 0.61 0.19 1.82 0.24 0.01 0.13 0.61 0.12 0.23 1.18 0.25 0.04 0.00 0.00 9.48 6.92 1.82 5.37 2.55 4.70 3.80 19.76 4.96 1.09 4.30 7.90 9.20 3.46 7.24 16.69 4.05 3.01 0.24 3.92 0.00 0.04 0.04 0.00 0.01 0.04 0.00 0.02 0.00 0.00 0.00 0.08 0.00 0.00 0.00 0.08 0.02 0.01 0.06 0.34 0.01 0.09 0.00 0.01 0.02 0.03 0.04 0.02 0.13 0.03 0.00 0.00 0.00 0.44 0.39 0.15 0.38 0.19 0.21 0.88 0.09 0.04 0.32 0.54 0.22 0.24 0.89 0.25 0.18 0.11 0.19 2 4 4 <1 4 1 <1 2 <1 1 0 1 <1 <1 <1 2 1 3 6 7 4 14 2 <.1 3 3 <1 4 15 3 0 0 0 26 15 115 23 20 17 64 69 6 13 15 21 31 23 15 56 24 65 <1 30 1 1 1 1 1 1 11 1 2 1 <.1 0 0 <.1 <1 <1 <1 2 <1 44 <1 <.1 5 <.1 <1 2 0 0 0 15 1 1 0 0 0 0 7 5 4 27 4 17 1 11 3 15 0 8 8 <1 11 6 2 10 29 3 0 0 0 0 0 0 0 0 0 0 0 0 <.1 0 <.1 0 0 0 <.1 0 <.1 0 0 0 <.1 <.1 0 0 0 0 0 0 <1 0 0 0 0 <1 <1 <1 2 <1 <.1 2 <1 1 <.1 <1 <1 <1 <1 1 <1 1 0 1 <.1 <.1 <.1 <.1 <.1 <.1 0 <1 2 0 <1 2 0 <1 <1 1 <.1 <1 1 <.1 5 19 18 15 27 29 22 16 11 10 1 22 h a p p e n d i x h-54 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 1574 32144 2793 28546 32146 29629 16649 1826 1814 16650 16622 25253 442 25105 16646 16788 1668 655 29637 25109 16637 497 28585 33073 28588 16821 16819 16820 25266 16824 25276 160 25241 16794 16818 1744 30287 30286 16546 8789 8624 1745 1908 30247 25283 16686 16547 16659 1906 31890 756 8793 8795 25134 1411 25133 30249 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans mixed foods, soups, sandwiches continued crab cakes, from blue crab enchiladas w/green chili sauce (enchiladas verdes) falafel patty fettuccine alfredo flautas fried rice w/meat or poultry general tso chicken green salad hummus kung pao chicken lamb curry lasagna w/ground beef macaroni & cheese meat loaf moo shi pork nachos w/beef, beans, cheese, tomatoes, & onions pepperoni pizza potato salad ravioli, meat lled, w/tomato or meat sauce, canned salisbury steaks w/mushroom sauce shrimp creole w/rice spaghetti & meat balls w/tomato sauce, prepared spicy thai noodles (pad thai) stir fried pork & vegetables w/rice stuffed shells sushi w/egg in seaweed sushi w/vegetables & sh sushi w/vegetables in seaweed sweet & sour pork tabouli, tabbouleh, or tabuli three bean salad tuna salad turkey & noodles vegetable egg roll vegetable sushi, no sh sandwiches bacon, lettuce & tomato w/mayonnaise bologna & cheese w/margarine bologna w/margarine cheese cheeseburger, large, plain cheeseburger, large, w/bacon, vegetables, & condiments club w/bacon, chicken, tomato, lettuce, & mayonnaise cold cut submarine w/cheese & vegetables corned beef egg salad fried egg grilled cheese gyro w/onion & tomato ham & cheese ham w/mayonnaise hamburger, double patty, large, w/condiments & vegetables hamburger, large, plain hamburger, large, w/vegetables & condiments hot chicken salad hot dog w/bun, plain hot turkey salad pastrami 1 1 3 1 3 1 1 3 4 1 2 1 1 1 1 1 1 7 2 1 2 1 1 1 1 8 1 21 2 6 6 6 3 4 1 1 2 1 2 1 2 6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 item(s) 60 43 93 item(s) item(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) slice(s) cup(s) item(s) slice(s) cup(s) cup(s) serving(s) cup(s) cup(s) ounce(s) cup(s) item(s) piece(s) piece(s) piece(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) piece(s) item(s) item(s) item(s) item(s) item(s) item(s) 144 51 222 162 198 146 104 123 162 236 237 200 115 151 551 142 125 251 135 243 248 231 235 299 156 156 156 249 160 99 103 319 128 156 164 111 83 83 185 195 104 18 81 78 129 91 99 80 88 188 157 122 85 77 284 66 95 196 102 176 174 74 173 189 117 102 110 206 124 82 65 228 90 99 97 46 34 31 72 85 207 170 247 438 329 293 17 218 431 256 288 393 244 512 1496 362 179 220 251 311 330 222 349 292 190 217 182 264 199 95 192 271 202 225 349 350 256 262 609 608 item(s) 246 137 555 item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 228 130 126 96 83 105 146 112 226 137 218 98 98 98 134 132 75 72 50 27 67 74 55 121 58 121 49 53 50 71 456 268 278 226 292 170 352 282 540 426 512 239 242 221 331 12 9 7 11 25 12 19 1 6 29 28 18 15 17 19 40 20 3 9 17 27 19 9 15 18 9 8 3 29 3 2 16 24 5 5 11 13 7 10 30 32 31 22 19 10 10 10 12 21 14 34 23 26 16 10 16 14 <1 18 16 42 36 41 16 3 25 11 3 22 40 7 5 119 40 14 38 9 28 39 36 34 33 20 44 41 17 16 10 10 21 20 50 34 28 26 27 47 37 48 51 25 29 26 27 21 33 27 40 32 40 23 18 23 27 0 3 0 1 4 1 1 2 5 2 1 2 1 <1 1 19 1 2 2 1 1 3 3 2 3 <1 2 1 1 4 3 0 1 2 2 2 1 1 1 0 2 3 2 2 1 1 1 1 2 1 0 2 3 1 2 1 2 5 0.89 1.69 1.36 12 9 3 22 12 17 <.1 11 31 14 15 19 16 46 99 14 10 4 15 9 12 6 16 10 8 1 <1 8 15 6 9 9 12 <1 19 20 13 13 33 37 26 19 10 13 9 16 4 15 13 27 23 27 9 15 7 18 6.35 1.22 1.61 8.22 2.27 3.98 0.01 1.38 5.19 3.93 7.47 8.18 6.15 6.84 22.34 4.47 1.79 1.58 5.98 1.83 3.90 0.83 5.55 3.81 2.09 0.16 0.10 2.59 2.04 0.76 1.58 2.39 2.46 0.11 4.54 8.55 4.08 5.59 14.84 3.65 5.19 0.79 8.80 3.53 6.27 0.00 6.04 13.95 4.92 4.84 6.72 6.89 14.80 40.19 6.28 3.10 1.49 6.67 3.79 4.40 3.33 6.87 3.57 3.02 0.14 0.11 3.51 10.83 1.41 2.96 3.48 5.71 0.10 7.22 8.40 6.31 4.77 12.74 0 0.96 2.12 0 0.43 2.29 5.69 5.27 0.04 2.56 9.69 3.35 0 0.84 2.66 0.83 0 22.07 30.69 2.33 4.67 0.41 0.76 2.88 2.20 1.83 2.62 1.62 1.55 0.20 0.11 1.48 1.37 3.48 4.23 2.27 2.65 0.14 6.07 2.28 2.07 1.67 2.44 16.24 14.49 2.71 5.94 6.81 3.75 2.96 2.29 6.22 1.53 6.44 3.06 8.23 3.96 3.97 3.51 6.29 1.41 6.74 5.04 10.52 8.38 10.33 9.88 10.42 2.83 5.11 2.23 6.18 11.42 2.61 6.85 1.76 8.74 2.28 0.80 4.79 1.64 2.54 0.43 1.38 3.79 2.80 2.14 2.20 2.76 1.71 2.28 1.02 0 0 0 0 0 0 0 0 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-55 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 205 17 19 1067 305 318 90 27 0 9 73 102 65 0 0 64 89 68 30 85 172 82 28 85 17 60 181 89 37 46 35 217 11 0 74 0 0 13 77 60 0 20 35 16 19 96 111 72 36 46 217 207 19 34 58 36 122 71 87 39 44 37 51 63 266 28 153 146 36 27 13 60 49 36 222 323 54 30 699 129 24 28 64 101 124 32 39 241 42 24 20 41 29 26 17 60 29 23 76 221 60 216 91 162 116 189 67 107 80 219 46 130 59 102 74 96 114 24 113 68 0.65 1.08 1.74 1.88 2.66 2.66 1.49 0.65 1.93 1.96 2.97 2.33 2.26 2.09 1.45 6.71 1.87 0.81 2.04 2.21 4.44 3.70 1.58 2.65 3.18 1.63 2.18 1.54 1.78 1.25 0.96 1.03 2.69 1.61 2.40 2.54 2.18 1.96 1.75 5.46 4.74 4.05 2.51 2.67 2.60 2.25 1.76 1.85 3.24 2.10 5.85 3.58 4.93 1.93 2.31 2.04 2.64 20 38 42 32 61 31 24 11 36 63 40 40 42 21 26 23 23 64 50 32 63 18 25 20 35 36 15 19 33 18 23 27 24 15 20 39 45 47 68 20 18 17 21 21 16 23 50 27 44 20 13 22 23 194 198 2.45 34 0.05 1.74 0.10 32 251 298 123 223 182 250 178 213 428 495 437 263 278 330 337 282 439 665 187 394 462 128 204 99 622 246 144 182 379 193 158 328 185 112 135 644 276 150 386 886 821 906 27 298 907 495 493 800 423 1078 1611 534 661 1354 370 381 1009 598 574 543 527 340 153 624 799 224 412 576 548 369 837 940 598 655 1589 1.27 0.77 1.48 3.44 1.42 1.40 0.22 1.34 1.50 6.62 2.81 1.95 3.55 1.83 7.55 1.04 0.39 1.19 3.66 1.73 1.08 2.07 1.68 0.98 0.79 0.70 2.53 0.48 0.31 0.57 2.64 0.51 0.84 0.98 1.68 0.85 1.14 5.55 332 1043 6.83 463 855 1.65 394 187 147 120 137 209 291 245 570 267 480 150 143 167 243 1651 1177 494 433 696 272 771 1033 791 474 824 470 670 459 1335 2.58 2.24 0.94 0.85 1.15 2.30 1.37 1.50 5.67 4.11 4.88 1.22 1.98 1.09 2.69 1 51 0 59 0 108 327 27 105 40 27 82 38 80 280 64 12 25 108 185 82 71 94 96 5 0 24 28 0 23 0.05 0.07 0.07 0.35 0.10 0.30 0.10 0.03 0.11 0.15 0.09 0.19 0.25 0.08 0.50 0.31 0.27 0.10 0.22 0.11 0.29 0.25 0.18 0.51 0.32 0.12 0.26 0.20 0.80 0.08 0.04 0.03 0.23 0.16 0.28 0.39 0.30 0.29 0.25 0.48 0.31 0.03 0.00 0.10 1.60 1.62 0.92 4.32 1.30 0.22 0.72 0.00 5.39 7.71 0.70 0.00 2.07 0.36 0.38 0.00 0.67 0.25 0.12 0.20 2.43 0.89 0.00 0.29 1.28 0.16 1.16 0.56 0.50 0.47 0.16 0.08 0.34 0.17 0.19 0.19 0.05 0.06 0.15 0.28 0.29 0.40 0.29 0.38 0.50 0.47 0.08 0.20 0.30 0.10 0.30 0.13 0.20 0.36 0.29 0.07 0.04 0.37 0.05 0.06 0.07 0.32 0.21 0.06 0.27 0.33 0.21 0.29 0.57 1.28 0.53 2.60 3.00 3.51 6.28 0.57 0.49 13.23 8.05 3.02 2.18 3.77 2.90 5.62 6.09 1.11 2.88 4.00 4.77 4.00 1.88 5.07 4.64 1.33 2.77 1.86 6.69 1.14 0.26 6.87 6.40 1.59 2.44 3.81 2.77 2.73 2.04 11.17 0.18 0.06 0.06 0.27 0.24 0.28 0.08 0.49 0.59 0.20 0.20 0.10 0.13 0.31 0.85 0.11 0.18 0.14 0.13 0.22 0.17 0.30 0.30 0.13 0.15 0.14 0.65 0.11 0.06 0.08 0.30 0.10 0.13 0.20 0.12 0.08 0.07 0.28 0.41 6.63 0.31 0.61 1.53 0.44 11.92 0.59 1.00 0.24 0.26 0.27 0.19 0.24 0.31 0.71 0.36 0.29 0.41 0.20 0.24 0.19 0.29 0.21 0.13 0.66 0.72 0.26 0.29 0.50 0.28 0.29 0.27 0.80 0.25 0.43 0.41 0.28 0.21 0.48 0.31 0.38 0.29 0.37 0.23 0.27 0.21 0.27 5.49 3.23 2.27 2.06 1.86 3.14 2.69 4.89 7.57 6.25 7.28 4.93 3.65 4.36 4.77 0.14 0.10 0.16 0.10 0.06 0.13 0.20 0.26 0.54 0.23 0.33 0.20 0.05 0.23 0.13 45 47 103 96 24 17 38 73 43 27 50 12 20 22 59 74 9 17 22 12 44 102 109 29 14 10 14 31 31 8 60 27 15 31 21 19 19 74 86 48 87 22 82 34 13 18 76 19 77 60 83 54 48 54 21 2 59 1 1 0 3 12 24 10 8 1 10 <1 <1 8 14 3 13 22 <1 18 22 22 18 15 2 4 2 10 29 9 2 1 6 4 15 <.1 <.1 <.1 0 2 9 12 2 1 0 <.1 4 3 0 1 0 3 <1 <.1 <1 2 4 <1 0 <1 1 <1 <1 0 0 <1 3 1 <1 2 1 1 <1 0 <1 2 1 <.1 <1 <1 <1 <1 0 1 0 0 1 1 <1 0 <1 1 <1 <1 3 2 1 1 1 1 <1 <1 1 1 <1 4 2 2 <1 1 <1 1 24 6 1 35 37 <1 3 22 17 26 5 17 22 3 23 36 50 3 42 34 39 33 31 24 23 26 27 34 17 26 20 h a p p e n d i x h-56 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 16701 30306 1910 1909 1907 25288 31891 30283 25296 711 713 825 826 25297 827 724 823 824 708 715 709 716 25298 16689 25138 16663 28054 28560 714 28561 717 28038 828 28036 28566 725 16667 28037 25140 718 710 719 726 28595 28051 720 28598 25141 721 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans mixed foods, soups, sandwiches continued peanut butter peanut butter & jelly roast beef, plain roast beef submarine w/mayonnaise & vegetables steak w/mayonnaise & vegetables tuna salad turkey w/mayonnaise turkey submarine w/cheese, lettuce, tomato, & mayonnaise soups bean bean with pork, condensed, prepared w/water beef noodle, condensed, prepared w/water cheese, condensed, prepared w/milk chicken broth, condensed, prepared w/water chicken noodle chicken noodle, condensed, prepared w/water chicken noodle, dehydrated, prepared w/water cream of asparagus, condensed, prepared w/milk cream of celery, condensed, prepared w/milk cream of chicken, condensed, prepared w/milk cream of chicken, condensed, prepared w/water cream of mushroom, condensed, prepared w/milk cream of mushroom, condensed, prepared w/water cream of vegetable egg drop golden squash hot & sour lentil chowder macaroni & bean manhattan clam chowder, condensed, prepared w/water minestrone minestrone, condensed, prepared w/water mushroom & wild rice new england clam chowder, condensed, prepared w/milk new england style clam chowder old country pasta onion, dehydrated, prepared w/water shrimp gumbo southwestern corn chowder split pea split pea with ham, condensed, prepared w/water tomato, condensed, prepared w/milk tomato, condensed, prepared w/water tomato vegetable, dehydrated, prepared w/water turkey noodle turkey vegetable vegetable beef, condensed, prepared w/water vegetable gumbo vegetable vegetarian vegetable, condensed, prepared w/water 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 item(s) item(s) item(s) item(s) item(s) item(s) item(s) 93 93 139 216 204 179 143 24 24 68 127 104 102 75 344 330 346 410 459 414 330 item(s) 277 156 583 cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) cup(s) 301 253 191 265 223 180 244 251 244 286 224 207 234 258 241 222 252 237 83 231 39 117 75 58 248 213 161 248 214 164 248 210 191 244 221 117 248 210 203 244 285 244 258 244 229 229 244 230 241 230 248 229 228 246 244 229 165 253 248 244 253 228 227 244 229 252 220 251 229 224 210 188 129 224 177 220 188 211 207 164 237 206 202 117 207 210 220 237 203 203 224 168 225 129 165 73 144 161 150 136 78 99 82 81 164 83 135 27 171 102 85 190 161 85 56 106 98 78 153 96 241 223 72 13 11 22 29 30 24 29 37 14 8 5 9 5 11 4 2 6 6 7 3 6 2 7 8 8 15 11 6 2 4 4 4 9 3 6 1 10 5 4 10 6 2 2 8 11 6 4 5 2 37 42 33 44 52 29 26 51 29 24 9 16 1 11 9 9 16 15 15 9 15 9 15 1 21 5 27 21 12 16 11 12 17 15 20 5 19 18 19 28 22 17 10 14 8 10 26 20 12 3 3 1 2 2 1 3 6 9 1 1 0 1 1 <1 1 1 <1 <1 <1 <1 2 0 2 1 12 5 1 5 1 2 1 2 3 1 3 2 2 2 3 <1 1 2 2 <1 3 4 17 15 14 13 14 22 11 25 2 6 3 15 1 3 2 1 8 10 11 7 14 9 9 4 4 8 <1 3 2 2 3 <1 7 <1 3 1 7 <1 <1 4 6 2 1 2 1 2 4 2 3.55 3.00 3.61 7.09 3.81 3.61 2.61 8.16 6.87 6.80 1.84 5.34 5.46 3.25 4.58 3.82 1.71 2.61 3.35 11.43 4.40 7.15 8.03 7.81 0.67 0.83 0.53 1.59 2.28 1.91 1.15 9.11 0.39 0.78 1.24 4.09 0.59 1.10 0.49 0.45 0.27 0.66 0.65 1.11 0.55 0.31 0.52 0.39 3.32 2.08 2.23 3.94 2.46 2.65 4.64 4.46 1.64 2.07 3.27 1.49 5.13 2.98 4.61 2.44 1.56 1.15 0.84 2.72 0.09 0.48 0.38 0.32 0.55 0.05 2.95 0.08 1.17 0.12 1.34 0.12 0.07 1.77 2.90 0.37 0.38 0.27 0.32 0.85 0.61 0.06 1.71 4.62 1.52 2.18 3.40 0.08 2.06 0.38 1.30 0.70 0.02 2.26 0.03 1.60 0.32 3.02 0.12 0.03 1.80 1.61 0.44 0.30 1.06 0.17 0.81 2.93 0.04 4.22 1.92 0.59 0.88 1.20 0.22 0.59 1.29 0.43 1.11 0.15 1.09 0.05 0.63 0.07 2.05 0.20 0.18 0.63 1.12 0.95 0.08 0.67 0.30 0.12 0.56 0.16 0.29 0.82 0.72 0 0 0 0 0 0 0 0 0 0 0 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-57 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 1 1 51 73 73 53 69 70 5 3 5 48 0 24 7 10 22 32 27 10 20 2 1 103 4 34 <1 <1 2 0 2 0 22 2 6 0 51 1 0 8 17 0 0 24 20 5 0 0 0 80 68 54 41 92 100 78 324 80 85 15 289 10 26 17 5 174 186 181 34 179 46 68 21 203 29 47 64 27 68 34 27 186 69 51 12 99 65 30 23 159 12 8 27 36 17 52 41 22 2.47 2.11 4.23 2.81 5.16 3.29 3.10 3.88 3.08 2.15 1.10 0.80 0.51 1.34 0.77 0.50 0.87 0.69 0.67 0.61 0.60 0.51 1.38 0.75 1.63 1.89 4.07 1.86 1.63 1.76 0.92 1.08 1.49 1.29 2.32 0.15 2.34 1.10 1.25 2.28 1.81 1.76 0.63 1.40 1.30 1.12 1.90 2.45 1.08 62 53 31 67 49 35 34 51 61 48 5 20 2 16 5 8 20 22 17 2 20 5 17 5 39 29 55 32 12 31 7 26 22 26 47 5 51 24 33 48 22 7 20 22 22 5 35 38 7 272 239 316 330 524 302 315 479 409 792 845 798 795 490 1.25 1.06 3.39 4.38 4.53 1.08 2.94 552 2408 2.66 590 690 1.41 421 996 1.09 100 341 210 335 55 33 952 1019 776 776 1.54 0.68 0.24 0.77 1106 0.39 577 0.20 360 1042 0.92 0 11 30 20 46 26 48 7 359 0 49 36 3 62 310 1009 0.20 114 0.07 273 1047 0.67 179 0.07 88 986 0.63 163 0.03 0.33 0.27 0.38 0.41 0.41 0.26 0.30 2.39 2.02 0.35 0.74 0.25 0.21 0.31 0.41 0.37 0.26 0.33 6.46 5.45 5.87 5.96 7.30 12.29 6.64 0.17 0.15 0.26 0.32 0.37 0.48 0.46 0.53 1.19 0.49 12.50 0.54 43 37 57 71 90 70 24 46 0.27 0.03 0.15 3.61 0.23 139 0.09 0.80 0.03 0.59 0.04 0.07 0.06 0.01 0.15 0.68 0.05 0.02 0.06 0.33 0.07 0.16 1.07 0.50 3.35 5.57 0.04 0.08 0.02 0.13 0.05 0.10 0.06 1.39 0.03 0.20 0.13 0.08 1.09 0.03 0.10 0.28 0.88 0.06 0.25 0.44 0.06 0.26 0.92 0.07 0.06 0.82 0.02 34 20 10 5 40 22 18 30 7 7 2 270 918 0.64 35 0.08 1.24 0.28 0.91 0.06 10 100 312 220 412 382 590 254 188 273 313 332 300 430 434 64 515 374 352 400 449 264 104 200 383 173 313 688 881 784 729 500 1561 26 489 578 423 911 267 992 236 319 849 515 200 608 1007 744 695 1146 372 328 791 471 674 0.59 0.74 0.48 1.72 1.51 1.44 0.46 0.98 0.38 0.75 0.87 0.79 0.66 0.69 0.05 0.93 0.73 0.57 1.32 0.30 0.24 0.18 0.67 0.90 1.54 0.56 0.78 15 100 454 163 174 56 138 118 4 57 34 114 0 46 112 23 64 29 10 81 110 95 15 118 0.05 0.12 0.02 0.17 0.27 0.21 0.15 0.03 0.10 0.05 0.06 0.07 0.07 0.20 0.03 0.19 0.08 0.12 0.15 0.13 0.09 0.06 0.20 0.08 0.04 0.17 0.12 0.95 1.06 0.29 0.53 0.12 0.06 0.35 0.34 0.23 0.07 0.45 0.02 0.01 0.00 1.90 0.09 0.00 1.24 2.32 0.35 0.02 0.01 0.37 0.58 0.00 0.09 0.20 0.19 0.38 0.25 0.12 0.13 0.04 0.10 0.04 0.21 0.24 0.12 0.15 0.06 0.10 0.14 0.09 0.08 0.25 0.05 0.05 0.11 0.09 0.05 0.07 0.13 0.72 3.27 3.03 1.15 4.97 1.69 1.36 0.82 0.69 0.94 2.97 1.03 1.02 2.42 0.48 2.54 1.65 1.67 1.47 1.52 1.42 0.79 2.68 3.33 1.03 1.59 2.37 0.01 0.12 0.05 0.15 0.20 0.30 0.09 0.10 0.07 0.10 0.14 0.13 0.20 0.23 0.00 0.19 0.22 0.21 0.07 0.16 0.11 0.05 0.15 0.27 0.08 0.16 0.27 210 822 0.46 116 0.05 0.05 0.92 0.06 5 37 15 32 13 164 59 10 47 36 18 10 17 65 2 59 27 61 3 17 15 10 45 21 10 51 33 10 0 <1 2 6 6 1 0 5 3 2 <1 1 0 1 <1 0 4 1 1 <1 2 1 10 0 10 1 13 7 4 12 1 4 3 12 17 <1 26 37 9 2 68 66 6 5 10 2 18 23 1 <.1 <.1 1 2 2 2 <1 2 <1 <.1 <1 <1 <1 <1 <1 <.1 <1 <1 1 <.1 <1 <.1 <1 <1 1 <1 0 0 4 0 0 <.1 10 3 <.1 0 <1 <1 0 <1 <1 0 0 <1 <1 <1 0 0 0 29 26 42 71 8 8 7 7 0 10 6 10 8 5 8 7 4 1 5 8 3 9 9 4 8 4 13 4 9 2 2 <1 8 2 <1 5 13 9 4 4 5 4 h a p p e n d i x h-58 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 36094 751 9279 36131 36045 36044 9265 752 36048 36047 33465 9267 36041 9291 9251 9249 750 2009 9269 9295 9293 36132 9273 36130 35371 35353 35354 35372 35357 35358 35359 35360 35361 35362 35364 35366 35373 35367 35368 34975 34976 34978 35006 34979 34973 35007 35057 35008 34980 34981 34983 34982 34967 34984 34985 34969 34988 34989 34970 35012 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fast food arby s au jus sauce beef n cheddar sandwich cheddar curly fries chocolate shake curly fries, large curly fries, medium fish llet sandwich ham n cheese sandwich homestyle fries, large homestyle fries, medium homestyle fries, small italian sub sandwich market fresh grilled chicken caesar salad w/o dressing roast beef deluxe sandwich, light roast beef sandwich, giant roast beef sandwich, junior roast beef sandwich, regular roast beef sandwich, super roast beef sub sandwich roast chicken deluxe sandwich, light roast turkey deluxe sandwich, light strawberry shake turkey sub sandwich vanilla shake auntie anne s cheese dipping sauce cinnamon sugar soft pretzel cinnamon sugar soft pretzel w/butter marinara dipping sauce original soft pretzel original soft pretzel w/butter parmesan herb soft pretzel parmesan herb soft pretzel w/butter sesame soft pretzel sesame soft pretzel w/butter sour cream & onion soft pretzel sour cream & onion soft pretzel w/butter sweet mustard dipping sauce whole wheat soft pretzel whole wheat soft pretzel w/butter boston market bbq baked beans black beans & rice butternut squash caesar side salad chicken gravy chicken pot pie cole slaw cornbread cranberry walnut relish creamed spinach glazed carrots green bean casserole green beans half chicken, w/skin homestyle mashed potatoes homestyle mashed potatoes & gravy honey glazed ham hot cinnamon apples macaroni & cheese meatloaf old-fashioned potato salad 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 4 1 3 4 1 1 1 3 4 1 3 4 3 4 3 4 3 4 3 4 1 3 4 1 5 3 4 3 4 5 3 4 serving(s) item(s) serving(s) serving(s) serving(s) serving(s) item(s) item(s) serving(s) serving(s) serving(s) item(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) serving(s) item(s) serving(s) serving(s) item(s) item(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) serving(s) item(s) item(s) cup(s) cup(s) cup(s) serving(s) ounce(s) item(s) cup(s) item(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) cup(s) cup(s) ounce(s) cup(s) cup(s) ounce(s) cup(s) 85 198 170 397 198 128 220 170 213 142 113 312 338 182 228 129 157 245 334 194 194 397 306 397 35 120 120 35 120 120 120 120 120 120 120 120 35 120 120 201 227 193 119 28 425 184 68 210 181 153 170 85 277 173 201 142 181 192 142 150 5 480 460 480 620 400 529 340 560 370 300 780 230 296 480 310 350 470 760 260 260 500 630 470 100 350 450 10 340 370 390 440 350 410 310 340 60 350 370 270 300 150 300 15 750 300 200 350 260 280 80 70 590 210 230 210 250 280 282 200 <1 23 6 10 8 5 23 23 6 4 3 29 33 18 32 16 21 22 35 23 23 11 26 10 3 9 8 0 10 10 11 10 11 12 9 9 1 11 11 8 8 2 5 0 26 2 3 3 9 1 1 1 70 4 4 24 0 13 20 3 1 43 54 84 78 50 50 35 79 53 42 49 8 33 41 34 34 47 47 33 33 87 51 83 4 74 83 4 72 72 74 72 63 64 66 66 8 72 72 48 45 25 13 2 57 30 33 75 11 35 9 6 4 30 32 10 56 33 15 22 <.1 2 4 0 7 4 2 1 6 4 3 3 3 6 3 2 2 3 3 3 3 0 2 0 0 2 3 0 3 3 4 9 3 7 2 2 0 7 7 12 5 6 1 0 2 3 1 3 2 4 2 2 0 2 3 0 3 1 1 2 <.1 24 24 16 30 20 27 13 24 16 13 53 8 10 23 13 16 23 48 5 5 13 37 15 8 2 9 0 1 4 5 13 6 12 1 5 2 2 5 5 10 6 26 1 46 19 6 5 20 15 5 4 33 9 9 8 5 11 17 12 0.02 8.00 6.00 8.00 7.00 5.00 9.20 7.00 4.50 6.00 4.00 3.50 15.00 3.50 3.00 5.00 10.00 4.50 6.00 7.00 16.00 1.00 0.50 8.00 9.00 7.00 4.00 0.00 5.00 0.00 0.00 2.00 2.50 7.00 1.00 4.00 0.00 3.00 1.00 0.00 1.50 0.00 2.00 1.50 4.00 4.50 0.00 14.00 3.00 1.50 0.00 13.00 3.00 1.50 0.50 10.00 5.00 5.00 3.00 0.50 6.00 7.28 2.00 10.60 2.00 0.00 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-59 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 0 90 5 45 0 0 43 90 0 0 0 120 80 42 110 70 85 85 130 40 40 15 100 45 10 0 25 0 0 10 10 30 0 15 0 10 40 0 10 0 0 20 15 0 110 20 25 0 55 0 5 0 290 25 25 75 0 30 68 15 0 100 60 500 0 0 90 150 0 0 0 250 200 130 60 60 60 80 300 100 80 350 200 500 100 20 30 0 30 30 80 60 20 20 30 40 0 30 30 100 40 80 100 0 40 60 0 0 250 40 20 40 0 40 60 0 20 300 91 60 0.00 3.60 1.80 0.72 2.70 1.80 3.78 2.70 1.80 1.08 0.72 2.70 1.80 4.50 5.40 2.70 3.60 3.60 4.50 2.70 1.80 0.36 0.36 1.08 0.00 1.98 2.34 0.00 2.34 2.16 1.80 1.80 2.88 2.70 1.98 2.16 0.00 1.98 2.34 3.60 1.80 1.08 0.72 0.00 4.50 0.72 1.08 5.40 2.70 1.08 0.72 0.36 2.70 0.36 0.36 1.08 0.36 1.44 2.46 1.08 450 392 386 1240 1290 370 1540 990 864 1450 1070 710 570 2440 920 826 1440 740 950 1130 2230 1010 980 340 2170 360 510 410 430 180 900 930 780 660 840 860 920 930 120 1100 1120 540 1050 560 690 180 1530 540 390 0 740 80 670 250 1010 590 780 1460 45 890 592 450 0 0 0 38 0 0 10 20 0 0 0 40 0 0 0 40 40 36 39 0 0 0 0 0 0 42 0 1150 0 108 0 0 1000 30 0 53 0 0 0.35 0.27 0.31 0.49 5.60 8.40 0 1 15 2 21 15 1 1 30 21 15 2 42 8 0 0 0 1 4 2 1 1 2 2 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 6 4 30 9 0 1 36 0 0 9 1 2 5 0 15 15 0 0 0 1 6 h a p p e n d i x h-60 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 34965 34966 34963 34964 34993 34968 34998 34999 35003 35004 35005 29731 3739 14249 14251 3808 14259 29732 14261 3809 14244 14245 14250 14255 14262 14248 14263 14256 39000 14258 1736 14243 10801 10862 10866 10855 10790 34864 10797 10799 34855 14238 10798 34856 10802 38925 34858 34867 10865 10818 10770 38746 38747 38748 38753 38752 38741 38771 38761 38766 38758 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fast food continued quarter chicken, dark meat, no skin quarter chicken, dark meat, w/skin quarter chicken, white meat, no skin or wing quarter chicken, white meat, w/skin & wing rice pilaf rotisserie turkey breast, skinless savory stuf ng squash casserole steamed vegetables sweet potato casserole whole kernel corn burger king biscuit with sausage, egg, & cheese bk broiler chicken sandwich cheeseburger chicken sandwich chicken tenders, 8 pieces chocolate shake, small croissanwich w/sausage & cheese croissanwich w/sausage, egg, & cheese double cheeseburger double whopper double whopper w/cheese fish fillet sandwich french fries, medium, salted french toast sticks hamburger hash brown rounds, small onion rings, medium tendercrisp chicken sandwich vanilla shake, small whopper whopper w/cheese carl s jr carl s catch sh sandwich carl s famous star hamburger charboiled chicken salad-to-go charboiled sante fe chicken sandwich chicken stars (6 pieces) chocolate shake, small crisscut fries double western bacon cheeseburger famous bacon cheeseburger french fries, small french toast dips w/o syrup hamburger onion rings six dollar burger spicy chicken sandwich strawberry shake, small super star hamburger vanilla shake, small western bacon cheeseburger chick fil-a biscuit w/bacon, egg, & cheese biscuit w/egg biscuit w/egg & cheese biscuit w/gravy biscuit w/sausage, egg, & cheese biscuit, plain carrot & raisin salad chargrilled chicken cool wrap chargrilled chicken garden salad chargrilled chicken sandwich 1 1 1 1 1 5 1 3 4 1 3 4 3 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 item(s) item(s) 95 125 item(s) 140 item(s) cup(s) ounce(s) cup(s) cup(s) cup(s) cup(s) cup(s) item(s) item(s) item(s) item(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) serving(s) item(s) serving(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) serving(s) item(s) item(s) serving(s) serving(s) item(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 152 137 142 132 187 102 181 146 189 258 133 224 123 333 107 157 189 374 399 185 117 112 121 75 91 310 305 291 316 201 254 350 220 90 595 139 308 279 92 105 119 127 539 198 595 345 595 225 155 135 148 191 189 78 91 245 275 157 190 320 170 280 140 170 190 330 30 280 180 650 550 360 660 340 620 420 520 540 980 1070 520 360 390 310 230 320 810 560 710 800 530 590 200 540 260 530 410 920 700 290 370 280 430 1000 480 510 790 470 660 430 340 390 310 540 260 130 380 180 280 22 30 33 40 2 36 4 7 2 3 5 20 30 19 25 22 12 14 19 32 52 57 18 4 6 17 2 4 28 11 31 36 18 24 25 28 13 14 5 51 31 5 6 14 7 39 14 14 41 15 31 16 11 13 5 18 4 1 29 22 26 1 2 2 2 24 3 27 20 6 39 30 38 52 31 53 20 72 23 24 32 52 53 44 46 46 31 23 40 72 56 52 53 55 50 12 37 14 96 43 65 51 37 42 36 53 72 47 91 51 78 64 38 38 38 44 43 38 22 54 9 30 0 0 0 0 1 0 2 3 2 2 2 1 3 2 3 1 2 1 1 2 4 4 2 4 2 2 2 3 6 1 4 4 2 3 4 2 1 0 4 3 3 3 1 1 3 6 2 0 3 0 3 1 1 1 1 1 1 2 3 3 1 10 21 4 12 4 1 8 24 0 13 4 46 25 17 39 19 32 31 39 31 62 70 30 18 20 13 15 16 47 32 43 50 28 32 7 31 16 10 24 50 41 14 20 9 22 82 26 10 47 11 30 24 16 21 13 33 11 5 6 6 7 3.00 6.00 1.00 3.50 0.50 0.00 1.50 13.00 0.00 4.50 0.50 14.00 5.00 8.00 8.00 5.00 21.00 11.00 14.00 15.00 22.00 27.00 8.00 5.00 4.50 5.00 4.00 4.00 8.00 21.00 13.00 18.00 7.00 9.00 3.00 8.00 4.50 7.00 5.00 21.00 13.00 3.00 2.50 3.50 5.00 25.00 5.00 7.00 15.00 7.00 12.00 9.00 4.50 7.00 3.50 13.00 2.50 1.00 3.00 3.00 1.50 1.89 1.02 1.71 6.55 1.35 0.84 4.85 0 1 0.50 2.20 3.50 0 2 1.93 1.50 2 2.50 1.12 4.50 4.50 0.50 5.0 3.50 4.28 0 1 2 2.85 3 2.98 3.98 2.67 2.97 0 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-61 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 115 155 85 135 0 100 5 70 0 10 0 190 105 50 70 50 95 45 210 100 160 185 55 0 0 40 0 0 60 95 85 110 80 70 75 95 40 45 0 155 95 0 0 35 0 135 40 45 130 50 85 265 245 260 5 280 0 0 70 70 70 0 0 0 0 20 20 40 200 40 40 0 150 60 150 80 20 350 100 300 250 150 300 150 20 60 76 0 97 80 300 150 250 150 100 150 200 20 600 20 300 200 0 40 80 20 350 100 600 100 600 200 150 80 150 60 150 60 20 200 150 80 1.08 1.80 0.72 1.08 1.08 1.80 1.44 0.72 0.35 1.08 0.36 2.70 3.60 3.60 2.70 0.72 1.08 3.60 4.50 4.50 9.00 9.00 2.70 0.72 1.80 3.60 0.36 0.00 4.50 0.36 6.30 6.30 1.80 4.50 1.80 2.70 1.08 1.08 1.80 7.20 5.40 1.08 1.08 2.70 0.72 5.40 2.70 0.00 7.20 0.00 5.40 3.60 2.70 2.70 1.80 3.60 1.80 0.36 2.70 0.72 1.80 440 500 480 510 520 850 620 1110 135 190 170 1600 1110 790 1330 840 310 840 1090 1050 1070 1500 840 640 440 580 450 460 1800 220 980 1420 1030 910 440 1210 480 350 950 1770 1310 180 430 480 700 1690 1220 330 980 350 1410 1070 740 960 930 1030 670 90 1060 660 980 0 0 0 0 0 389 20 90 63 42 140 100 14 0 0 9 0 0 39 52 157 60 0 0 0 102 0 0 0 0 0 0 40 0 0 0 0.46 0.25 0.47 0.14 0.11 0.36 0.26 0.40 0.40 0.16 0.19 0.25 0.11 0.14 0.11 0.39 0.39 0.26 0.23 0.32 0.30 0.12 0.56 0.42 0.45 0.60 0.67 0.48 0.22 0.29 0.07 0.09 0.64 0.44 0.51 0.24 10.50 4.18 9.59 10.93 0.24 4.35 6.37 11.08 11.07 2.32 2.86 4.26 2.11 2.33 0.22 7.33 7.31 2.00 0 0 0 0 4 0 2 5 18 9 5 0 6 1 0 0 0 0 0 1 9 9 1 9 0 1 1 0 9 0 9 9 2 6 5 6 0 0 12 1 6 21 0 1 4 21 6 0 9 0 1 0 0 0 0 0 0 4 6 30 2 h a p p e n d i x h-62 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 38759 38742 38743 38762 38757 38764 38756 38768 38763 38770 38755 38765 38778 38774 38775 38776 38777 38769 38767 38772 39569 39572 39571 39567 39568 39573 39570 1466 38552 38561 1464 38541 17257 1463 1462 38555 38547 17256 31606 31604 37551 37548 31573 31574 37543 37545 37546 37547 31569 31570 37538 37540 31685 31694 31686 31695 31575 31576 31687 31696 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fast food continued chargrilled deluxe chicken sandwich chicken biscuit chicken biscuit w/cheese chicken caesar wrap chicken deluxe sandwich chicken salad sandwich chicken sandwich chick-n-strip salad chick-n-strips coleslaw hash browns hearty breast of soup icedream, small cone icedream, small cup lemonade lemonade, diet nuggets side salad southwest chargrilled salad waf e potato fries, small, salted cinnabon caramel pecanbon caramellata chill w/whipped cream cinnapoppers classic roll minibon mochalatta chill w/whipped cream stix dairy queen banana split brownie earthquake chocolate chip cookie dough blizzard, small chocolate malt, small chocolate shake, small chocolate soft serve chocolate sundae, small dipped cone, small oreo cookies blizzard, small royal treats peanut buster parfait vanilla soft serve domino s barbeque wings breadsticks buffalo chicken kickers cinnastix classic hand tossed pizza america s favorite feast, 12" america s favorite feast, 14" bacon cheeseburger feast, 12" bacon cheeseburger feast, 14" barbeque feast, 12" barbeque feast, 14" cheese, 12" cheese, 14" deluxe feast, 12" deluxe feast, 14" deluxe, 12" deluxe, 14" extravaganzza, 12" extravaganzza, 14" hawaiian feast, 12" hawaiian feast, 14" meatzza, 12" meatzza, 14" 1 1 1 1 1 1 1 1 4 1 1 1 1 1 1 1 8 1 1 1 1 16 1 1 1 16 5 1 1 1 1 1 1 2 1 1 1 1 1 2 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) serving(s) cup(s) item(s) serving(s) cup(s) cup(s) item(s) item(s) item(s) serving(s) item(s) uid ounce(s) serving(s) item(s) item(s) uid ounce(s) item(s) item(s) serving(s) item(s) item(s) item(s) cup(s) item(s) item(s) item(s) item(s) cup(s) item(s) item(s) item(s) item(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) 195 137 151 227 208 153 170 331 127 105 84 241 135 213 255 255 113 108 303 85 272 480 74 221 92 480 85 369 304 319 418 397 94 163 156 283 305 94 25 37 24 32 14 8 99 205 138 283 60 198 121 275 85 192 262 115 159 219 102 201 273 138 213 273 127 245 171 329 105 204 283 147 213 139 293 290 400 450 460 420 350 410 390 290 210 170 140 160 230 170 25 260 60 240 280 1100 406 368 813 339 362 379 510 740 720 650 560 150 280 340 570 730 140 50 116 47 122 508 697 549 762 506 691 375 516 465 627 465 627 576 773 450 623 560 753 27 16 19 36 28 20 28 34 29 1 2 8 4 5 0 0 26 3 22 3 16 10 4 15 6 9 6 8 10 12 15 13 4 5 6 11 16 3 6 3 4 2 22 30 25 35 22 30 15 21 20 26 20 26 27 36 21 29 26 35 31 43 43 52 39 32 38 22 14 14 20 18 28 38 41 5 12 4 17 37 141 61 41 117 49 55 41 96 112 105 111 93 22 49 42 83 99 22 2 18 3 15 57 79 55 75 62 85 55 75 57 78 57 78 59 88 58 80 57 78 2 2 2 2 2 5 1 4 1 2 2 1 0 0 0 0 1 2 5 5 8 0 2 4 2 0 1 3 0 0 0 1 0 0 1 1 2 0 <1 1 <1 1 4 5 3 4 3 4 3 4 3 5 3 5 4 5 3 5 3 5 7 18 23 10 16 15 15 18 13 17 9 4 4 6 1 0 12 3 8 14 56 14 21 32 13 13 21 12 27 28 16 15 5 7 17 21 31 5 2 4 2 6 22 30 26 36 20 27 11 15 18 24 18 24 27 36 16 22 26 34 1.50 4.50 7.00 6.00 3.50 3.00 3.50 5.00 2.50 2.50 4.50 1.00 2.00 3.50 0.00 0.00 2.50 1.50 3.50 5.00 0.00 10.00 8.00 11.00 8.00 3.00 8.00 6.00 3.00 8.00 16.00 14.00 10.00 10.00 3.50 1.00 4.50 9.00 4.00 10.00 17.00 3.00 0.65 0.79 0.39 1.15 9.20 12.70 11.62 16.10 9.08 12.24 4.81 6.72 7.66 10.20 7.65 10.20 11.56 15.42 7.20 10.09 11.40 15.24 0.00 0.50 1.00 3.00 0 2.83 2.85 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1.50 5 1 5 2 4 0 3 2.50 0.50 0.50 0 0 1 2.50 0 0 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-63 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 70 30 45 80 60 65 60 80 65 20 10 25 15 25 0 0 70 10 60 15 63 46 62 67 27 46 16 30 50 50 55 50 15 20 20 40 35 15 26 0 9 0 49 68 60 84 46 63 23 32 40 53 40 53 60 89 41 57 344 85 80 60 150 500 100 150 100 200 20 40 0 40 100 150 0 0 40 100 200 20 100 250 250 350 450 450 100 200 200 350 300 150 6 <.1 3 6 202 281 293 395 393 187 261 199 276 199 276 290 403 274 384 282 393 1.80 2.70 2.70 2.70 2.70 1.80 2.70 0.36 0.36 0.36 0.72 1.08 0.36 0.00 0.36 0.36 1.08 0.00 1.08 0.00 0.00 1.80 1.80 2.70 1.80 1.44 0.72 1.08 1.08 2.70 1.80 0.72 0.32 0.87 0.00 0.70 3.70 5.10 3.56 4.96 4.42 2.99 4.13 3.56 4.84 3.56 4.85 4.08 5.48 3.30 4.57 3.71 5.04 860 278 290 990 1200 1430 1390 1300 880 1300 860 730 180 350 900 80 100 10 5 1090 75 770 105 600 187 104 801 337 252 413 180 350 370 370 280 75 140 130 430 400 70 175 152 163 110 1221 1685 1274 1809 1206 1672 776 1080 1063 1432 1063 1432 1348 1780 1102 1544 1463 1947 0 0 0 0 0 150 131 184 0.15 0.12 0.06 0.06 0.60 0.24 0.26 0.20 0.20 0.20 5 0 0 1 2 0 0 30 1 27 0 0 0 0 15 15 0 15 24 21 0 15 0 1 2 2 0 0 1 1 1 0 <.1 6 0 <.1 1 1 0 0 2 0 0 1 2 1 2 1 2 2 3 <1 <1 h a p p e n d i x h-64 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 31571 31572 31577 31578 37549 31605 31607 31583 31584 31579 31580 31688 31697 31689 31698 31585 31586 31690 31699 31581 31582 31587 31588 31596 31702 31590 31591 31589 31691 31700 31692 31701 31599 31600 31693 31703 31593 31594 31602 31603 31598 31595 31592 31601 34374 34391 34390 34377 34375 34393 34392 34376 34373 34389 34388 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fast food continued pepperoni feast, extra pepperoni & cheese, 12" pepperoni feast, extra pepperoni & cheese, 14" vegi feast, 12" vegi feast, 14" dot cinnamon double cheesy bread hot wings thin crust pizza america s favorite, 12" america s favorite, 14" cheese, 12" cheese, 14" deluxe, 12" deluxe, 14" extravaganzza, 12" extravaganzza, 14" hawaiian, 12" hawaiian, 14" meatzza, 12" meatzza, 14" pepperoni, extra pepperoni & cheese 12" pepperoni, extra pepperoni & cheese 14" vegi, 12" vegi, 14" ultimate deep dish pizza america s favorite, 12" america s favorite, 14" cheese, 12" cheese, 14" cheese, 6" deluxe, 12" deluxe, 14" extravaganzza, 12" extravaganzza, 14" hawaiian, 12" hawaiian, 14" meatzza, 12" meatzza, 14" pepperoni, extra pepperoni & cheese 12" pepperoni, extra pepperoni & cheese 14" vegi, 12" vegi, 14" with ham & pineapple tidbits, 6" with italian sausage, 6" with pepperoni, 6" with vegetables, 6" in-n-out burger cheeseburger cheesburger w/mustard & ketchup cheeseburger, lettuce leaves instead of buns chocolate shake double-double cheeseburger double-double cheeseburger w/mustard & ketchup double-double cheeseburger, lettuce leaves instead of buns french fries hamburger hamburger w/mustard & ketchup hamburger, lettuce leaves instead of buns 2 2 2 2 1 1 1 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 1 4 2 2 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 slice(s) 196 87 slice(s) slice(s) slice(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 270 203 278 28 35 25 121 107 147 8 11 159 202 106 148 159 202 159 202 159 202 159 202 item(s) 159 item(s) item(s) item(s) slice(s) slice(s) slice(s) slice(s) item(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) 202 159 202 235 311 181 257 215 235 311 235 311 235 311 235 311 slice(s) 235 slice(s) slice(s) slice(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 311 235 311 430 430 430 430 268 268 300 425 328 item(s) 328 item(s) item(s) item(s) item(s) 361 125 243 243 item(s) 275 534 732 439 304 99 123 45 408 557 273 382 363 494 425 571 349 489 458 619 420 586 338 471 617 851 482 677 598 527 788 635 866 558 784 667 914 629 880 547 765 619 642 647 619 480 400 330 690 670 590 520 400 390 310 240 24 33 19 27 2 4 5 19 26 12 17 16 22 20 27 18 25 23 31 20 28 16 22 26 36 19 26 23 23 31 27 36 24 35 30 40 26 37 22 32 25 25 25 23 22 22 18 9 37 37 33 7 16 16 12 56 77 57 78 15 13 1 34 47 31 43 34 47 34 48 35 48 33 46 32 45 34 47 59 84 56 80 68 59 84 59 85 60 85 58 83 57 82 59 84 70 70 69 71 39 41 11 83 40 42 11 54 39 41 10 3 4 4 5 1 1 <1 2 3 2 2 2 3 3 4 2 3 2 3 2 3 3 3 4 5 3 5 4 4 5 4 6 4 5 4 5 4 5 4 6 4 4 4 5 3 3 2 0 3 3 2 2 3 3 2 25 34 16 22 4 6 2 23 31 12 17 19 25 24 31 16 23 27 36 24 34 17 23 33 44 22 30 28 29 38 34 45 26 36 37 49 34 47 26 36 28 31 32 29 27 18 25 36 41 32 39 18 19 10 17 10.92 15.00 7.09 9.89 0.68 2.06 0.65 9.77 13.19 9.37 6.72 7.64 10.20 9.41 12.44 7.20 10.09 11.39 15.24 10.46 14.55 7.08 9.89 12.88 17.35 7.91 10.88 9.94 10.75 14.36 12.52 16.60 10.31 14.25 14.50 19.40 13.57 18.71 10.19 14.05 10.19 11.33 11.70 10.11 10.00 9.00 9.00 24.00 18.00 17.00 17.00 5.00 5.00 4.00 4.50 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-65 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 57 78 34 47 0 6 26 51 69 23 32 40 53 53 69 41 57 64 454 54 76 34 47 58 78 30 41 36 47 62 60 78 48 67 379 501 61 85 41 57 43 45 47 36 60 55 60 95 120 115 120 0 40 35 40 279 390 279 389 6 47 5 318 444 225 315 237 330 245 340 312 437 320 446 316 442 317 442 334 464 241 335 295 253 349 261 359 328 457 336 466 332 462 333 462 298 302 299 307 200 200 200 300 350 350 350 20 40 40 40 3.36 4.66 3.44 4.71 0.59 0.66 0.30 1.52 2.07 0.97 1.36 1.54 2.08 1.95 2.59 1.28 1.80 1.69 2.27 1.34 1.87 1.42 1.94 4.43 6.24 3.88 5.53 4.67 4.45 6.25 4.86 6.76 4.19 5.97 4.60 6.44 4.25 6.04 4.33 6.11 4.84 4.89 4.81 5.10 3.60 3.60 1.08 0.72 5.40 5.40 1.08 1.80 3.60 3.60 1.08 1349 1855 987 1369 86 164 354 1285 1751 835 1172 1123 1523 1408 1871 1162 1635 1523 2039 1362 1900 1047 1460 1573 2155 1123 1575 1341 1410 1927 1696 2275 1449 2039 1810 2443 1650 2304 1334 1864 1498 1478 1524 1472 1000 1080 720 350 1430 1510 1160 245 640 720 370 155 233 125 175 162 227 151 210 174 187 260 168 188 182 143 184 229 275 0 50 75 <1 <1 1 2 <.1 <1 1 <1 1 0 0 1 2 1 2 2 3 <1 <1 <1 <1 1 2 1 1 <1 1 1 2 2 2 2 2 3 1 1 1 1 2 2 1 1 1 5 15 15 18 0 15 15 18 0 15 15 18 h a p p e n d i x h-66 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 34379 34378 30392 1740 14074 14106 37241 14111 14075 14098 14099 14073 14090 14072 1468 1469 1470 33141 14095 14077 37249 14112 14078 14110 31646 31647 38422 31648 31649 31650 31651 31652 31654 38423 31656 31657 38424 38426 31660 31665 31667 31668 31669 38421 38427 38428 31850 31853 31851 31842 31849 3761 3762 3763 3764 31833 10810 10813 10811 10812 10859 31848 h x i d n e p p a food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fast food continued strawberry shake vanilla shake jack in the box bacon ultimate cheeseburger breakfast jack cheeseburger chicken breast pieces chicken club salad chocolate ice cream shake double cheeseburger french fries, jumbo french fries, super scoop hamburger hash browns jack s spicy chicken sandwich jumbo jack hamburger jumbo jack hamburger w/cheese onion rings sausage, egg, & cheese biscuit seasoned curly fries sourdough jack southwest chicken salad strawberry ice cream shake ultimate cheeseburger vanilla ice cream shake jamba juice banana berry smoothie caribbean passion smoothie carrot juice chocolate mood smoothie citrus squeeze smoothie coffee mood smoothie coldbuster smoothie cranberry craze smoothie jamba powerboost smoothie lemonade lime sublime smoothie mango-a-go-go smoothie orange juice, freshly squeezed orange/carrot juice orange-a-peel smoothie protein berry pizzaz smoothie raspberry refresher smoothie razzmatazz smoothie strawberries wild smoothie strawberry tsunami smoothie vibrant c juice wheatgrass juice, freshly squeezed kentucky fried chicken (kfc) bbq baked beans biscuit coleslaw colonel s crispy strips corn on the cob extra crispy chicken, breast extra crispy chicken, drumstick extra crispy chicken, thigh extra crispy chicken, whole wing honey bbq wing pieces hot & spicy chicken, breast hot & spicy chicken, drumstick hot & spicy chicken, thigh hot & spicy chicken, whole wing hot wings pieces macaroni & cheese 1 1 1 1 1 5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 24 24 16 24 24 24 24 24 24 16 24 24 16 16 24 24 24 24 24 24 16 1 1 1 1 3 1 1 1 1 1 6 1 1 1 1 6 1 item(s) item(s) item(s) item(s) item(s) piece(s) item(s) item(s) item(s) serving(s) serving(s) item(s) serving(s) item(s) item(s) item(s) serving(s) item(s) serving(s) item(s) serving(s) item(s) item(s) item(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) ounce(s) serving(s) item(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) piece(s) serving(s) 425 425 353 133 116 150 535 315 155 142 198 104 57 253 269 294 119 223 125 244 598 313 328 285 719 730 472 612 729 560 724 731 730 483 721 739 496 484 726 710 636 730 725 740 448 32 156 56 142 150 162 162 60 114 52 189 179 60 128 55 135 153 690 680 1120 310 300 360 310 660 410 410 580 250 150 580 600 690 500 760 400 700 340 640 990 570 470 440 100 690 450 596 430 420 440 300 450 500 220 160 440 440 442 480 450 530 210 5 190 180 232 340 150 470 160 370 190 607 450 140 390 180 471 180 8 9 52 14 14 27 28 11 20 4 6 12 1 24 22 26 6 25 6 30 28 10 41 12 5 4 3 16 4 13 5 6 6 1 3 4 3 3 9 20 3 3 6 4 2 1 6 4 2 28 5 34 12 21 10 33 33 13 22 11 27 7 91 78 59 34 31 24 15 89 32 55 77 30 13 53 58 60 51 33 45 36 31 84 59 65 112 102 23 142 105 121 100 97 103 75 104 117 52 37 102 92 101 112 105 128 50 1 33 20 26 20 35 19 5 12 10 33 20 4 14 9 18 21 2 2 2 1 2 1 5 1 1 4 6 2 2 3 3 3 3 2 5 3 9 0 2 0 5 4 0 2 5 1 5 4 7 0 6 4 1 0 5 6 8 4 4 4 1 0 6 1 3 0 2 0 0 0 0 1 0 0 0 0 2 2 33 37 55 14 13 17 16 29 22 20 28 9 10 31 31 38 30 60 23 49 13 28 66 29 2 2 1 8 2 6 3 2 2 0 2 2 1 1 1 2 3 2 0 2 0 0 3 10 14 16 2 28 10 26 12 38 27 9 28 11 33 8 22.00 25.00 28.00 5.00 6.00 3.00 6.00 18.00 11.00 4.50 6.00 3.50 2.50 6.00 11.00 16.00 5.00 20.00 5.00 16.00 6.00 18.00 28.00 18.00 0.50 1.00 0.00 4.50 1.00 4.00 1.00 1.00 0.00 0.00 1.00 1.00 0.00 0.00 0.00 0.00 0.90 1.00 0.00 1.00 0.00 0.00 0.00 0.00 0.00 1.00 2.50 2.00 4.50 0.00 8.00 2.50 7.00 3.50 10.00 8.00 2.50 8.00 3.00 8.00 3.00 0.00 0.00 0.00 3.13 0 0.89 4.48 0 1 5.34 7.07 0.88 3 2.81 1.55 1.55 10 5.72 7 2.98 0 1 3.05 1 0 0 0 0.29 3.44 0.27 4.47 0 4.50 1.50 3 2 5.42 0 0 0 0 4.03 2.81 page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-67 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 85 90 160 210 40 80 65 110 70 0 0 30 0 60 45 75 0 280 0 80 60 110 130 115 5 5 0 25 5 28 5 5 0 0 5 5 0 0 0 0 3 5 0 5 0 0 5 0 8 70 0 135 70 120 55 193 130 65 125 60 150 10 250 300 300 150 150 20 300 350 250 20 20 100 10 150 164 250 40 100 40 200 300 350 300 400 200 100 150 500 150 455 100 250 1100 20 150 100 60 100 250 1100 104 150 250 100 20 0 80 20 30 10 10 19 9 19 9 40 10 20 10 10 40 150 0.00 0.00 7.20 3.60 3.60 1.80 3.60 0.36 4.50 1.08 1.44 3.60 0.18 1.80 4.92 4.50 2.70 2.70 1.80 4.50 4.50 0.00 7.20 0.00 1.08 1.80 2.70 1.08 1.80 0.30 1.08 1.44 1.44 0.00 1.80 1.08 1.08 1.80 1.80 2.62 2.20 1.80 1.80 1.08 1.08 1.80 1.80 1.08 0.18 0.72 0.18 1.44 0.65 1.04 0.34 1.44 1.07 0.68 1.44 0.72 1.44 0.18 32 24 80 32 60 49 60 16 480 8 32 24 60 60 60 39 56 32 32 24 40 8 600 210 180 430 1010 720 280 550 770 155 190 470 390 420 140 240 580 450 1020 610 480 630 1000 810 1030 760 1150 634 1240 500 1110 200 660 800 990 1010 1350 650 806 790 1020 480 720 80 280 390 2260 770 840 970 890 270 920 690 960 610 230 950 980 1360 420 1390 890 1220 920 220 1670 220 85 60 250 280 50 429 35 90 40 10 75 60 0 125 100 240 47 70 115 10 0 0 760 560 284 1140 20 1230 415 710 390 1145 1450 380 1240 420 1230 860 0.30 0.30 0.90 0.60 0.30 1.50 15.00 0.30 15.00 0.00 0.60 0.30 0.30 0.60 0.30 0.58 0.80 0.60 0.30 0.30 0.30 0.00 134 145 40 215 0 0 0 0 40 202 218 0 0 0 0 0 0 0 0 0 65 10 350 0.06 0.09 0.53 0.09 0.30 0.10 0.38 0.03 5.25 0.03 0.12 0.15 0.45 0.45 0.38 0.09 0.10 0.09 0.03 0.06 0.30 0.03 0.32 0.64 0.00 0.40 0.16 17.71 0.64 17.71 0.00 0.32 1.61 0.64 0.31 0.40 0.32 0.32 0.26 0.26 0.26 0.85 0.26 0.60 0.34 0.26 5.78 0.17 0.26 0.26 0.14 0.26 0.43 0.10 0.30 0.26 0.34 0.34 0.10 0.03 1.20 5.00 5.00 0.40 1.90 0.30 3.00 5.00 66.00 14.00 7.00 5.00 2.00 3.00 3.00 1.55 1.60 6.00 1.20 14.00 1.60 0.40 0.40 0.50 0.70 0.08 0.40 0.10 0.40 0.50 6.80 1.80 0.80 0.70 0.20 0.50 0.40 0.40 0.40 0.90 0.20 1.80 0.40 0.04 33 100 80 9 100 18 122 100 640 320 160 120 160 120 140 58 43 160 32 320 80 16 0 0 1 4 0 1 54 0 1 6 9 0 0 9 10 9 18 0 0 9 48 0 1 0 15 78 18 6 168 7 1302 54 294 36 66 72 246 132 240 60 35 60 60 90 678 4 1 1 34 1 4 1 1 1 1 5 1 1 1 1 1 1 0 0 0 1 0 1 0 0 10 0 <1 0 0 0 0 0 <1 0 0 0 0 0 0 1 6 4 1 3 1 1 70 0 1 1 0 3 1 4 1 1 1 1 0 3 h a p p e n d i x h-68 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 31847 10825 10826 10827 10828 3760 31834 31852 10845 10853 10851 10852 31843 10854 39392 3777 37568 37569 39404 39398 3770 39394 39400 3774 3779 3781 39399 39395 2247 737 738 29775 3792 1873 73 29774 743 742 2257 1872 2244 33822 2251 739 2003 2249 33816 33817 33818 38396 38397 38398 38399 1874 740 741 2005 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fast food continued mashed potatoes with gravy original recipe chicken, breast original recipe chicken, drumstick original recipe chicken, thigh original recipe chicken, whole wing original recipe chicken sandwich w/sauce original recipe chicken sandwich w/o sauce potato salad potato wedges rotisserie gold chicken, breast & wing w/skin rotisserie gold chicken, thigh & leg w/skin rotisserie gold chicken, thigh & leg w/o skin spicy crispy strips tender roast chicken, breast w/o skin long john silver baked cod batter dipped sh sandwich battered sh breaded clams clam chowder cocktail sauce coleslaw crunchy shrimp basket french fries, large fries regular hushpuppy shrimp batter-dipped tartar sauce ultimate sh sandwich mcdonald s barbecue sauce big mac hamburger cheeseburger chicken mcgrill sandwich chicken mcnuggets chicken mcnuggets chocolate milkshake crispy chicken sandwich egg mcmuf n filet-o- sh sandwich french fries, large french fries, small french fries, super size fruit n yogurt parfait garden salad hamburger hash browns honey sauce mcsalad shaker chef salad mcsalad shaker garden salad mcsalad shaker grilled chicken caesar salad newman s own cobb salad dressing newman s own creamy caesar salad dressing newman s own low fat balsamic vinaigrette salad dressing newman s own ranch salad dressing plain hotcakes w/syrup & margarine quarter pounder hamburger quarter pounder hamburger w/cheese sausage mcmuf n w/egg 1 1 1 1 1 1 1 1 1 4 4 4 3 1 1 1 1 1 1 1 1 21 1 1 1 1 1 1 1 1 1 1 4 6 8 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3 1 1 1 serving(s) item(s) item(s) item(s) item(s) 136 161 59 126 47 item(s) 200 item(s) serving(s) serving(s) 187 160 156 ounce(s) 114 ounce(s) 114 ounce(s) item(s) item(s) serving(s) item(s) item(s) serving(s) item(s) ounce(s) serving(s) item(s) item(s) serving(s) piece(s) piece(s) ounce(s) item(s) serving(s) item(s) item(s) item(s) item(s) item(s) uid ounce(s) item(s) item(s) item(s) serving(s) serving(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 117 115 118 101 177 92 85 227 28 113 114 142 85 23 14 28 199 28 216 121 213 72 108 164 227 219 138 156 176 68 198 338 177 107 53 14 206 149 163 59 item(s) 59 item(s) item(s) item(s) item(s) item(s) item(s) 44 59 228 172 200 164 120 370 140 360 145 450 360 230 376 218 260 217 335 169 120 440 230 240 220 25 200 340 390 230 60 45 100 500 45 590 330 400 210 310 270 500 300 470 540 210 610 380 35 280 130 45 150 100 100 120 190 40 290 600 430 530 450 1 40 14 22 11 29 29 4 6 26 23 27 25 31 22 17 11 8 9 0 1 12 4 3 1 2 0 20 0 24 15 25 10 15 7 22 18 15 8 3 9 10 2 12 1 0 17 7 17 1 2 0 1 9 23 28 20 17 11 4 12 5 33 21 23 53 1 1 0 23 1 1 48 16 22 23 6 15 32 56 34 9 3 4 48 10 47 36 37 12 18 48 46 29 45 68 26 77 76 7 35 14 12 5 4 3 9 4 4 4 104 37 38 29 2 0 0 0 0 2 1 3 5 0 0 0 1 0 0 3 0 1 0 0 4 2 5 3 1 0 0 3 0 3 2 2 1 2 1 2 2 1 6 2 7 2 3 2 1 0 2 2 2 0 0 0 0 0 2 2 2 6 19 8 25 9 22 13 14 15 12 18 12 15 4 5 20 13 13 10 0 15 19 17 10 3 3 9 25 0 34 14 17 13 20 6 26 12 26 26 10 29 5 0 10 8 0 8 6 3 9 18 3 30 17 21 30 28 1.00 6.00 2.00 7.00 2.50 5.00 3.50 2.00 4.20 3.51 5.15 3.50 4.00 1.20 1.00 5.00 4.00 2.00 4.00 0.00 2.50 5.00 4.00 2.50 0.50 1.00 1.50 8.00 0.00 1.76 7.40 0.00 0.00 11.00 6.00 3.00 2.50 4.00 1.77 3.81 4.50 4.50 5.00 4.50 1.50 5.00 2.00 0.00 0.00 4.00 1.50 0.00 0.00 3.50 3.00 1.50 1.50 3.50 0.00 4.50 3.00 8.00 13.00 10.00 0.00 4.10 5.10 0.00 0.23 0.00 0.00 0.50 2.50 1 1.50 1 0.31 6.12 0 0 1.48 1.02 0 1.13 1.69 1.50 0.42 1.11 6.18 2.30 0.18 0 0.51 2 0.01 0.29 0.01 0.22 4 1.01 1.51 0.59 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-69 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 1 145 75 165 60 70 60 15 4 102 127 128 70 112 90 35 30 10 25 0 20 105 0 0 0 15 15 50 0 85 45 60 35 50 25 50 235 50 0 0 0 15 0 30 0 0 95 75 40 10 20 0 20 20 70 95 255 10 20 10 10 10 40 40 20 36 7 8 10 20 10 20 60 20 20 150 0 40 500 0 0 20 0 0 150 10 300 250 200 20 20 299 200 300 200 20 10 20 300 40 200 10 10 150 150 100 40 60 10 40 100 200 350 300 0.36 1.14 0.70 1.00 0.36 1.80 1.80 2.70 1.55 0.12 0.14 0.18 0.90 0.18 0.72 3.60 1.80 1.08 0.72 0.00 0.36 1.80 0.00 0.00 0.36 0.00 0.00 3.60 0.18 4.50 2.70 2.70 0.72 0.72 0.70 2.70 2.70 1.80 1.44 0.36 1.44 1.80 1.09 2.70 0.36 0.18 1.44 1.08 1.08 0.18 0.18 0.18 0.18 4.50 4.50 4.50 2.70 36 223 370 45 430 250 440 180 260 508 400 210 280 1210 470 1370 550 410 230 210 7 360 290 420 13 16 9 64 280 370 420 260 440 1145 440 1060 370 940 890 540 1323 718 764 772 1140 797 240 1120 700 1110 810 250 340 720 580 350 200 125 250 1310 250 1090 830 890 460 680 252 1100 830 890 350 135 390 240 20 590 330 0 740 120 240 440 500 730 530 770 840 1310 930 0.70 0.30 1.09 100 34 3 60 60 41 40 5 323 273 10 100 115 0.07 0.09 0.11 0.11 0.72 0.00 15.40 0.00 0.72 0.08 0.02 0.50 2.35 1.60 0.28 0.06 11 1 1 1 1 1 1 1 1 8 1 1 1 1 1 0 9 5 0 0 0 18 1 24 15 0 1 0 9 4 4 2 6 1 1 0 6 1 1 21 9 24 24 24 2 2 1 15 15 12 1 1 2 1 1 2 2 1 1 4 h a p p e n d i x h-70 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 3163 74 39009 14025 14026 31009 14024 14031 14032 31011 14030 10834 10842 39013 14028 14029 31010 14027 39012 39011 38042 38052 38053 38054 38059 38057 38051 38088 32562 38079 38075 32561 38067 38078 38069 38070 38071 38073 38072 38080 38074 33111 33112 33109 33110 33107 38089 33108 38084 38083 38087 38063 38076 38077 38065 38066 38045 38046 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fast food continued strawberry milkshake vanilla milkshake pizza hut hot chicken wings meat lovers hand tossed pizza meat lovers pan pizza meat lovers stuffed crust pizza meat lovers thin n crispy pizza pepperoni lovers hand tossed pizza pepperoni lovers pan pizza pepperoni lovers stuffed crust pizza pepperoni lovers thin n crispy pizza personal pan pepperoni pizza personal pan supreme pizza personal pan veggie lovers pizza veggie lovers hand tossed pizza veggie lovers pan pizza veggie lovers stuffed crust pizza veggie lovers thin n crispy pizza wing blue cheese dipping sauce wing ranch dipping sauce starbucks apple cider, tall steamed cappuccino, tall cappuccino, tall nonfat cappuccino, tall soy milk cinnamon spice mocha, tall nonfat w/o whipped cream cinnamon spice mocha, tall w/whipped cream espresso, single shot flavored syrup, 1 pump frappuccino coffee drink, lite mocha frappuccino, grande chocolate malt frappuccino, grande mocha malt frappuccino low fat coffee drink, all avors frappuccino, tall caramel frappuccino, tall chocolate frappuccino, tall chocolate brownie frappuccino, tall coffee frappuccino, tall espresso frappuccino, mocha frappuccino, tall mocha coconut frappuccino, tall vanilla frappuccino, tall white chocolate latte, tall w/nonfat milk latte, tall w/whole milk macchiato, tall caramel w/nonfat milk macchiato, tall caramel w/whole milk mocha coffee drink, tall nonfat, w/o whipped cream mocha syrup mocha, tall w/whole milk tazo chai black tea, tall tazo chai black tea, tall nonfat tazo chai black tea, tall soy milk tazo chai creme frappuccino, tall tazo iced tea, tall tazo tea, grande lemonade tazoberry creme frappuccino, tall tazoberry frappuccino, tall vanilla creme steamed nonfat milk, tall w/whipped cream vanilla creme steamed soy milk, tall w/whipped cream 8 8 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 12 12 12 12 12 12 1 1 91 2 16 12 91 2 12 12 12 12 12 12 12 12 12 12 12 12 12 12 1 12 12 12 12 12 12 16 12 12 12 12 uid ounce(s) uid ounce(s) 226 227 168 169 item(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) slice(s) item(s) item(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) 57 125 130 188 112 114 119 171 94 59 73 69 120 125 181 110 43 43 360 360 360 360 uid ounce(s) 360 uid ounce(s) uid ounce(s) serving(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) serving(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) uid ounce(s) 360 30 10 281 480 360 281 360 360 360 360 360 360 360 360 360 335 360 360 325 360 360 360 17 360 360 360 360 360 360 480 360 360 uid ounce(s) 360 uid ounce(s) 360 256 254 110 320 360 500 310 300 350 480 270 150 170 150 220 260 370 190 230 210 180 120 80 100 170 320 5 20 100 470 430 190 210 290 270 190 160 220 300 260 240 123 212 140 190 180 25 340 210 170 190 280 60 120 240 140 180 300 8 9 11 16 16 25 15 15 15 23 13 7 8 6 10 10 17 8 2 1 0 7 7 5 11 10 0 0 7 15 14 6 4 13 5 4 4 5 5 11 5 12 11 7 6 12 1 12 6 6 4 11 0 0 4 1 12 8 43 40 1 30 29 44 22 30 29 44 22 18 19 19 31 31 45 23 2 4 45 10 11 13 32 31 1 5 12 87 91 39 43 52 51 38 33 44 58 47 48 17 17 27 27 33 6 33 36 37 39 51 16 31 54 36 32 37 1 0 0 2 2 3 2 2 2 3 2 1 1 2 2 3 2 0 0 0 0 0 1 0 0 0 0 3 2 1 0 0 1 1 0 0 0 2 0 0 0 0 0 0 1 0 1 0 0 1 0 0 0 1 1 0 1 6 7 6 15 20 25 18 14 19 24 14 6 7 6 6 12 14 7 24 22 0 6 0 3 0 17 0 0 3 10 7 3 3 5 7 3 2 3 7 4 4 1 11 1 7 2 1 20 5 0 2 4 0 0 1 0 0 12 3.93 4.28 1.98 0.26 2.00 7.00 7.00 11.00 8.00 7.00 8.00 11.00 7.00 2.50 3.00 2.00 3.00 4.00 7.00 3.00 5.00 3.50 0.25 0.53 0.53 1.11 0.57 0.50 0.50 1.05 0.51 0.97 0.95 0.50 0.25 0.26 0.53 0.54 1 0.50 0.00 4.00 0.00 0.00 0.00 0.00 0.00 0.00 0.50 0.00 0.00 11.00 0.00 0.00 0.00 0.00 2.00 3.50 4.00 2.00 1.50 1.00 4.50 1.50 1.50 1.50 5.00 1.00 2.50 0.40 6.90 0.40 4.00 1.50 0.00 12.00 3.50 0.00 0.00 1.00 0.00 0.00 0.00 0.00 0.16 3.24 0.68 3.48 0.00 0.00 0.00 0.00 0.00 0.00 0.02 0.42 0.08 0.44 0.00 0.00 0.00 0.00 0.00 0.00 0.00 6.00 0 0 0 0 0 0 0 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-71 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 25 27 70 40 40 65 45 40 40 65 40 15 15 10 15 15 35 15 25 10 0 25 3 0 5 70 0 0 13 15 20 12 10 3 10 10 10 10 10 3 10 6 46 25 25 5 0 47 20 5 0 3 0 0 0 0 5 30 256 331 0 150 150 250 150 200 200 300 200 80 80 80 150 150 250 150 20 0 0 250 200 250 300 350 0 0 200 250 250 220 150 400 150 150 100 150 150 400 150 420 400 250 200 350 0 300 200 200 200 400 0 0 150 0 350 400 0.25 0.23 0.36 1.80 2.70 2.70 1.80 1.80 2.70 2.70 1.44 1.44 1.86 1.80 1.80 2.70 2.70 1.44 0.00 0.00 1.08 0.00 0.00 0.72 0.72 1.08 0.00 0.00 1.08 2.70 1.08 0.00 0.00 1.80 1.44 0.00 0.00 0.72 1.08 0.00 0.00 0.18 0.18 0.36 0.36 2.70 0.72 0.18 0.36 0.36 0.72 0.00 0.00 0.00 0.00 0.00 0.00 1.44 29 27 40 47 412 415 188 215 0.82 0.88 254 450 830 810 1450 880 730 710 1300 700 340 400 280 490 470 980 480 550 340 15 95 100 75 150 140 0 0 80 420 390 110 180 300 220 180 160 180 220 280 210 174 165 110 105 150 0 169 85 95 70 280 0 15 125 30 170 130 1.35 1.28 59 57 58 58 58 38 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.10 0.07 0.11 0.44 0.44 0.40 0.33 0.10 0.10 7 16 0.12 0.13 0.47 0.54 0.36 0.35 0.14 0.14 18 17 2 0 0 6 6 9 9 2 2 4 2 1 4 4 9 9 12 12 0 0 0 1 0 0 0 2 0 0 0 12 0 0 0 5 0 0 0 0 0 4 0 4 3 2 1 2 0 2 1 0 0 4 0 5 1 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 5 5 h a p p e n d i x h-72 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 38044 38090 38062 38061 38048 38047 38050 34023 38622 38623 34029 32045 32048 32049 4024 16397 3422 4030 34030 3885 34026 34027 4651 15839 32046 32047 3957 16403 16378 34028 4032 4031 34024 32050 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melt sandwich, 6", italian bread horseradish roast beef sandwich, 6", italian bread meatball sandwich, 6", white bread melt sandwich, 6", white bread oatmeal raisin cookie peanut butter cookie roast beef sandwich, 6", white bread roasted chicken breast salad roasted chicken breast sandwich, 6", white bread southwest steak & cheese sandwich, 6", italian bread spicy italian sandwich, 6", white bread steak & cheese sandwich, 6", white bread steak & cheese wrap sugar cookie tuna salad tuna sandwich, 6", white bread turkey breast & ham sandwich, 6", white bread turkey breast & bacon wrap turkey breast sandwich, 6", white bread veggie delite, 6", white bread white macadamia nut cookie taco bell 7-layer burrito bean burrito beef burrito supreme beef chalupa supreme beef gordita supreme beef soft taco beef soft taco supreme big beef burrito supreme big chicken burrito supreme chicken burrito supreme chicken chalupa supreme 12 1 12 12 12 12 12 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 uid ounce(s) serving(s) 360 27 uid ounce(s) 360 uid ounce(s) 360 uid ounce(s) 360 uid ounce(s) 360 uid ounce(s) 360 item(s) 244 item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 213 199 127 48 48 48 250 323 253 254 147 219 item(s) 258 item(s) item(s) item(s) item(s) item(s) item(s) item(s) 230 284 256 48 48 220 304 item(s) 234 item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) 255 213 253 245 48 314 252 229 228 220 163 48 283 198 248 153 153 99 134 291 255 248 153 340 100 260 410 300 460 420 413 480 430 302 209 210 210 453 145 294 415 291 261 373 401 501 380 197 220 264 137 311 412 458 362 353 222 238 419 267 318 254 200 221 530 370 440 390 310 210 260 510 460 410 370 10 0 12 11 15 13 11 22 40 32 14 3 2 2 21 17 22 19 15 17 23 18 23 23 3 3 18 16 25 23 19 23 22 2 13 18 18 19 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= mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-73 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 75 40 5 70 10 75 35 46 90 65 185 12 13 12 56 30 30 57 189 25 41 27 56 41 14 0 20 36 48 44 57 37 37 18 42 42 23 24 15 0 13 25 10 40 40 35 25 40 60 70 45 45 40 0 400 400 450 500 500 40 350 300 60 0 0 0 100 40 40 150 60 40 100 40 100 100 0 0 40 40 60 100 30 100 150 0 100 100 40 60 40 40 0 300 200 200 150 150 100 150 150 101 200 100 0.00 0.00 0.00 0.00 0.00 0.00 1.44 2.70 2.70 2.70 1.80 1.00 1.00 1.00 2.70 1.80 3.60 3.60 2.70 2.70 2.70 3.60 3.60 2.70 1.00 1.00 3.60 1.08 3.60 6.30 3.00 6.30 7.20 1.00 1.08 2.70 2.70 2.70 2.70 1.80 1.00 3.59 2.69 2.70 1.80 2.70 1.80 1.80 2.70 1.46 2.70 1.08 493 160 10 210 210 250 250 210 1320 1340 1650 480 135 135 150 1740 1070 1250 1670 700 1260 1570 880 1350 1690 180 200 840 730 880 1120 1498 1200 1400 170 880 1180 1210 1490 1000 500 140 1360 1200 1330 600 590 620 630 1500 1200 1270 530 0 0 0 0 0 0 0 0 0 0 60 100 67 0 0 60 0 177 100 0 53 351 44 73 877 0.07 2 0 0 2 0 4 0 15 7 5 15 0 0 0 24 30 24 24 15 24 24 24 24 24 0 0 24 30 24 24 13 24 15 0 30 24 24 15 24 24 0 5 5 9 5 5 2 5 5 2 9 5 0 0 0 0 0 0 0 h a p p e n d i x h-74 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 29900 29895 10794 14465 29911 14463 29912 29904 29905 2021 2011 2012 34473 33419 29899 747 2015 14459 748 29901 29961 14788 29960 29957 14777 1741 39418 33759 1743 1914 1915 3986 3996 3987 36979 9425 9306 9316 9322 9359 9451 2363 2313 11138 2366 11116 11146 11152 11043 11046 360 9467 11055 9479 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans fast food continued chicken fajita wrap supreme choco taco ice cream dessert cinnamon twists grilled chicken burrito grilled chicken gordita supreme grilled chicken soft taco grilled steak gordita supreme grilled steak soft taco grilled steak soft taco supreme mexican pizza nachos nachos bellgrande steak burrito supreme steak chalupa supreme steak fajita wrap supreme taco taco salad w/salsa, with shell taco supreme tostada veggie fajita wrap supreme convenience meals banquet barbeque chicken meal boneless white fried chicken meal fish sticks meal lasagna with meat sauce meal macaroni & cheese meal meatloaf meal pepperoni pizza meal roasted white turkey meal salisbury steak meal budget gourmet cheese manicotti w/meat sauce chicken w/fettucini light beef stroganoff light sirloin of beef in herb sauce light vegetable lasagna healthy choice bowls chicken teriyaki with rice cheese french bread pizza chicken enchilada suprema meal lemon pepper sh meal traditional salisbury steak meal traditional turkey breasts meal zucchini lasagna stouffers cheese enchiladas with mexican rice cheese french bread pizza cheese manicotti w/tomato sauce chicken pot pie homestyle baked chicken breast w/mashed potatoes & gravy homestyle beef pot roast & potatoes homestyle roast turkey breast w/stuf ng & mashed potatoes lean cuisine cafe classics baked chicken & whipped potatoes w/stuf ng lean cuisine cafe classics honey mustard chicken lean cuisine everyday favorites chicken chow mein w/rice lean cuisine everyday favorites fettucini alfredo lean cuisine everyday favorites lasagna w/meat sauce lean cuisine french bread deluxe pizza 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 item(s) item(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) serving(s) serving(s) serving(s) item(s) item(s) item(s) item(s) serving(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) item(s) serving(s) serving(s) item(s) item(s) item(s) item(s) 255 113 35 198 153 99 153 127 135 216 99 308 248 153 255 78 533 113 170 255 281 234 187 312 340 269 191 255 197 269 284 194 284 177 248 214 269 227 298 298 170 320 252 303 354 250 298 383 276 294 255 284 252 252 item(s) 273 item(s) 227 item(s) 213 item(s) 255 item(s) 262 item(s) item(s) 291 174 510 310 160 390 290 190 290 280 240 550 320 780 420 370 510 170 790 220 250 470 330 490 270 320 420 240 480 230 380 420 380 290 260 290 330 360 360 280 360 330 280 370 370 330 740 260 270 300 240 260 210 280 300 330 20 3 0 19 17 14 16 12 15 21 5 20 19 15 21 8 31 9 11 11 16 14 13 15 15 14 11 14 12 18 20 20 19 15 19 20 13 11 23 21 13 12 14 17 23 19 16 16 17 18 12 13 19 18 53 37 28 49 28 19 28 21 20 46 33 80 50 29 52 13 73 14 29 55 37 49 31 46 57 20 56 30 28 38 33 32 30 36 50 57 59 49 45 50 47 48 43 35 56 21 25 34 33 37 33 40 41 44 3 1 0 3 2 0 2 1 2 7 2 12 6 2 3 3 13 3 7 3 2 2 3 7 5 4 5 5 3 4 3 3 5 5 5 5 8 5 5 4 5 5 3 3 4 1 3 2 3 1 2 2 3 3 24 17 5 13 12 6 13 17 11 31 19 43 16 22 25 10 42 14 10 22 13 27 10 9 14 11 23 6 24 22 19 7 7 9 6 5 7 5 9 5 4 14 16 13 47 11 12 11 5 4 3 7 8 9 7.76 10.00 1.00 4.00 5.00 2.50 6.00 4.50 5.00 11.00 4.50 13.00 7.00 8.00 8.00 4.00 15.00 7.00 4.00 7.00 3.00 7.00 3.00 4.00 8.00 4.00 8.00 2.00 12.00 11.00 6.00 10.00 4.00 2.30 4.00 0.89 1.79 2.00 1.50 3.00 2.00 3.50 2.00 2.50 2.00 2.00 1.00 4.00 1.50 1.34 0.31 0.60 2.00 2.00 2.00 1.00 1.50 1.50 0 0.50 1 5 5 10 2 3 0.50 8.75 1 1.50 5.00 6.00 8.00 18.00 12.41 10.48 3.00 4.50 3.00 1.50 1.50 1.00 1.50 1.00 1.00 1.00 1.00 0.50 3.50 2.00 1.00 4.00 3.50 2.00 1.50 0.50 1.00 0 0 0 0 0 0 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-75 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 57 20 0 40 45 30 35 30 35 45 4 35 35 35 50 25 65 40 15 30 50 65 30 20 20 30 35 25 60 85 85 35 30 15 40 10 30 30 45 35 10 25 15 40 65 50 35 35 30 35 30 20 30 20 165 60 0 151 100 100 100 100 100 350 80 200 200 100 150 60 400 80 150 150 40 60 60 100 150 0 150 60 40 300 100 40 40 283 20 350 40 40 80 40 200 200 200 350 150 20 20 40 80 60 20 200 200 100 1.52 0.72 0.37 1.44 1.80 1.08 2.70 1.44 1.08 3.60 0.72 2.70 2.70 1.44 1.80 1.08 6.23 1.44 1.44 1.44 1.08 1.08 1.44 2.70 1.44 1.80 1.80 1.80 1.44 2.70 2.70 1.80 1.80 3.03 0.72 3.60 1.44 0.36 2.70 1.44 1.80 1.44 1.80 1.08 2.70 0.72 1.80 0.72 0.72 0.36 0.36 0.36 1.08 1.80 45 39 58 79 484 280 540 420 360 240 430 500 790 1182 100 150 1240 530 550 520 650 510 1030 530 1300 1260 520 1200 350 1670 360 710 990 1210 1150 690 1170 1330 1040 870 1070 1140 810 810 580 850 780 600 600 580 580 580 600 310 890 880 810 1170 760 820 450 1190 480 690 370 640 310 620 260 670 590 390 650 630 2.29 4.71 4.81 1.39 0 15 29 29 0 162 789 44 73 281 0 0 0 0 0 0 0 0 0.45 0.15 0.17 0.16 0.22 0.51 0.43 0.37 0.29 0.45 4.00 6.00 4.28 5.53 3.13 0.23 0.27 0.37 0.32 31 19 38 75 7 0 0 2 5 1 4 4 4 6 0 6 9 4 6 2 21 5 5 6 5 0 2 0 0 0 0 4 0 0 0 2 6 59 15 12 4 30 21 0 0 12 0 1 2 0 6 0 0 0 0 0 5 9 1 3 2 <1 h a p p e n d i x h-76 appendix h table h 1 food composition (da+ code is for wadsworth diet analysis program) (for purposes of calculations, use 0 for t, <1, <.1, <.01, etc.) -da + code 11164 11155 11187 31514 31512 787 778 779 604 770 801 910 760 772 762 758 food description quantity measure wt (g) h2o (g) ener (kcal) prot (g) carb (g) fiber (g) fat (g) fat breakdown (g) sat mono poly trans convenience meals continued weight watchers smart ones chicken enchiladas suiza entree smart ones garden lasagna entree smart ones pepperoni pizza smart ones spicy penne pasta & ricotta smart ones spicy szechuan style vegetables & chicken baby foods apple juice applesauce, strained bananas w/tapioca, strained carrots, strained chicken noodle dinner, strained green beans, strained human milk, mature mixed cereal, prepared w/whole milk mixed vegetable dinner, strained rice cereal, prepared w/whole milk teething biscuits 1 1 1 1 1 4 4 4 4 4 4 2 4 2 4 1 serving(s) item(s) item(s) item(s) 255 312 158 289 item(s) 255 uid ounce(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) tablespoon(s) uid ounce(s) ounce(s) ounce(s) ounce(s) item(s) 127 64 60 56 64 60 62 114 57 114 11 112 55 50 52 55 0.05 54 85 50 85 1 270 270 390 280 220 60 31 34 15 42 15 43 128 23 131 43 15 14 23 11 11 0 <1 <1 <1 2 0.77 1 5 1 4 1 33 36 46 45 39 15 8 9 3 6 3.53 4 18 5 19 8 2 5 4 4 3 <1 1 1 1 1 1.13 0 1 1 <1 <1 9 7 12 6 2 <1 <1 <.1 <.1 1 0.05 3 4 <.1 4 <1 3.50 3.50 4.00 2.00 0.50 0.02 0.02 0.02 0.01 0.38 0.01 1.24 2.19 0.00 2.64 0.17 0.00 0.01 0.01 0.00 0.55 0 1.02 1.25 0.00 1.02 0.16 0.04 0.04 0.01 0.03 0.30 0.03 0.31 0.43 0.06 0.16 0.09 h x i d n e p p a page key: h 28 = dairy h 34 = eggs h 34 = seafood h 36 = meats h 40 = poultry h 40 = processed meats h 42 = beverages h 46 = fats/oils h 48 = sweets h 50 = spices/condiments/sauces h 52 = mixed foods/soups/sandwiches h 58 = fast food h 74 = convenience meals h 76 = baby foods h 14 = vegetables/legumes h 24 = nuts/seeds h 26 = vegetarian h 2 = breads/baked goods h 6 = cereal/rice/pasta h 10 = fruit table of food composition h-77 chol (mg) calc (mg) iron (mg) magn (mg) pota (mg) sodi (mg) zinc (mg) vit a ( g) thia (mg) vit e (mg (cid:2)) ribo (mg) niac (mg) vit b6 (mg) fola ( g) vit c (mg) vit b12 ( g) sele ( g) 50 30 45 5 10 0 0 0 0 10 0 9 12 0 12 0 250 350 450 150 150 5 3 3 12 17 23.39 20 250 12 272 29 1.08 1.80 1.80 2.70 1.80 0.72 0.14 0.12 0.21 0.41 0.44 0.02 11.85 0.19 13.85 0.39 4 2 6 5 9 14.39 2 31 6 51 4 320 250 115 45 53 110 89 94.8 31 226 69 216 36 660 610 650 400 730 4 1 5 21 15 1.2 10 53 5 52 40 0.04 0.01 0.04 0.08 0.35 0.12 0.10 0.81 0.09 0.73 0.10 55 1 1 1 321 70 27 38 28 77 25 3 0.01 0.01 0.01 0.01 0.03 0.01 0.01 0.49 0.01 0.53 0.03 0.76 0.38 0.36 0.29 0.13 0.31 0.05 0.03 0.02 0.02 0.02 0.02 0.04 0.05 0.02 0.66 0.02 0.57 0.06 0.11 0.04 0.11 0.26 0.46 0.2 0.11 6.56 0.29 5.91 0.48 0.04 0.02 0.07 0.04 0.04 0.02 0.01 0.07 0.04 0.13 0.01 0 1 4 8 7 21 3 12 5 9 5 4 6 5 6 2 73 25 10 3 <.1 3.11 3 1 2 1 1 0 0 0 0 <.1 0 <.1 <.1 0 <1 <.1 <1 <1 <1 <1 2 0.18 1 <1 4 3 h a p p e n d i x this page intentionally left blank canada: guidelines and meal planning i-1 who: nutrition recommendations canada: guidelines and meal planning contents nutrition recommendations from who eating well with canada s food guide canada s meal planning for healthy eating this appendix presents nutrition recommendations from the world health orga- nization (who) and details for canadians on the eating well with canada s food guide and the beyond the basics meal planning system. -nutrition recommendations from who the world health organization (who) has assessed the relationships between diet and the development of chronic diseases. -its recommendations include: energy: suf cient to support growth, physical activity, and a healthy body weight (bmi between 18.5 and 24.9) and to avoid weight gain greater than 11 pounds (5 kilograms) during adult life total fat: 15 to 30 percent of total energy saturated fatty acids: <10 percent of total energy polyunsaturated fatty acids: 6 to 10 percent of total energy omega-6 polyunsaturated fatty acids: 5 to 8 percent of total energy omega-3 polyunsaturated fatty acids: 1 to 2 percent of total energy trans fatty acids: <1 percent of total energy total carbohydrate: 55 to 75 percent of total energy sugars: <10 percent of total energy protein: 10 to 15 percent of total energy cholesterol: <300 mg per day salt (sodium): <5 g salt per day (<2 g sodium per day), appropriately iodized fruits and vegetables: (cid:2)400 g per day (about 1 pound) total dietary ber: >25 g per day from foods physical activity: one hour of moderate-intensity activity, such as walking, on most days of the week eating well with canada s food guide figure i-1 presents the 2007 eating well with canada s food guide, which interprets canada s guidelines for healthy eating (see table 2-2 on p. 40) for consumers and rec- ommends a range of servings to consume daily from each of the four food groups. -additional publications, which are available from health canada through its web- site, provide many more details. -search for canada s food guide at health canada: www.hc-sc.gc.ca i a p p e n d i x i-2 appendix i figure i-1 eating well with canada s food guide i x i d n e p p a figure i-1 eating well with canada s food guide continued canada: guidelines and meal planning i-3 i a p p e n d i x i-4 appendix i figure i-1 eating well with canada s food guide continued i x i d n e p p a figure i-1 eating well with canada s food guide continued canada: guidelines and meal planning i-5 i a p p e n d i x i-6 appendix i figure i-1 eating well with canada s food guide continued i x i d n e p p a figure i-1 eating well with canada s food guide continued canada: guidelines and meal planning i-7 i a p p e n d i x i-8 appendix i i x i d n e p p a canada s meal planning for healthy eating beyond the basics: meal planning for healthy eating, diabetes prevention and manage- ment is canada s system of meal planning.1 similar to the u.s. exchange system, beyond the basics sorts foods into groups and de nes portion sizes to help people manage their blood glucose and maintain a healthy weight. -because foods that contain carbohydrate raise blood glucose, the food groups are organized into two sections those that contain carbohydrate (presented in table i-1) and those that contain little or no carbohydrate (shown in table i-2). -one portion from any of the food groups listed in table i-1 provides about 15 grams of available carbohydrate (total carbohydrate minus ber) and counts as one carbohydrate choice. -within each group, foods are identi ed as those to choose more often (generally higher in vitamins, minerals, and fiber) and those to choose less often (generally higher in sugar, saturated fat, or trans fat). -1the tables for the canadian meal planning system are adapted from beyond the basics: meal planning for healthy eating, diabetes prevention and management, copyright 2005, with permission of the cana- dian diabetes association. -additional information is available from www.diabetes.ca. -key: choose more often choose less often table i-1 food groups that contain carbohydrate 1 serving = 15 g carbohydrate or 1 carbohydrate choice food measure grains and starches: 15 g carbohydrate, 2 g protein, 0 g fat, 286 kj (68 kcal) bagel, large bagel, small bannock, fried bannock, whole grain baked barley, cooked bread, white bread, whole grain bulgur, cooked bun, hamburger or hotdog cereal, aked unsweetened cereal, hot chapati, whole wheat (6(cid:3)) corn couscous, cooked crackers, soda type croutons english muf n, whole grain french fries millet, cooked naan bread (6(cid:3)) pancake (4(cid:3)) pasta, cooked pita bread, white (6(cid:3)) pita bread, whole wheat (6(cid:3)) pizza crust (12(cid:3)) plantain, mashed potatoes, boiled or baked 1 4 1 2 1.5(cid:3) (cid:4) 2.5(cid:3) 1.5(cid:3) (cid:4) 2.5(cid:3) 125 ml (1 2 c) 30 g (1 oz) 30 g (1 oz) 125 ml (1 2 c) 1 2 125 ml (1 2 c) 3 4 c 1 125 ml (1 2 c) 125 ml (1 2 c) 7 2 3 c 1 2 10 1 3 c 1 4 1 125 ml (1 2 c) 1 1 1 12 1 3 c 1 2 medium (continued on the next page) canada: guidelines and meal planning i-9 table i-1 food groups that contain carbohydrate continued 1 serving = 15 g carbohydrate or 1 carbohydrate choice food measure grains and starches: 15 g carbohydrate, 2 g protein, 0 g fat, 286 kj (68 kcal) rice, cooked roti, whole wheat (6(cid:3)) soup, thick type sweet potato, mashed taco shells (5(cid:3)) tortilla, whole wheat (6(cid:3)) waf e (4(cid:3)) 1 3 c 1 250 ml (1 c) 1 3 c 2 1 1 fruits:15 g carbohydrate, 1 g protein, 0 g fat, 269 kj (64 kcal) apple apple sauce, unsweetened banana blackberries cherries fruit, canned in juice fruit, dried grapefruit grapes kiwi juice mango melon orange other berries pear pineapple plum raspberries strawberries 1 medium 125 ml (1 2 c) 1 small 500 ml (2 c) 15 125 ml (1 2 c) 50 ml (1 4 c) 1 small 15 2 medium 125 ml (1 2 c) 1 2 medium 250 ml (1 c) 1 medium 250 ml (1 c) 1 medium 3 4 c 2 medium 500 ml (2 c) 500 ml (2 c) milk and alternatives: 15 g carbohydrate, 8 g protein, variable fat, 386 651 kj (92 155 kcal) chocolate milk, 1% evaporated milk, canned milk, uid milk powder, skim soy beverage, avored soy beverage, plain soy yogurt, avored yogurt, nonfat, plain yogurt, skim, arti cially sweetened 125 ml (1 2 c) 125 ml (1 2 c) 250 ml (1 c) 30 ml (2 tbs) 125 ml (1 2 c) 250 ml (1 c) 1 3 c 3 4 c 250 ml (1 c) other choices (sweet foods and snacks): 15 g carbohydrate, variable protein and fat brownies, unfrosted cake, unfrosted cookies, arrowroot or gingersnap jam, jelly, marmalade milk pudding, skim, no sugar added muf n oatmeal granola bar popcorn, low fat pretzels, low fat, large pretzels, low fat, sticks sugar, white 2(cid:3) (cid:4) 2(cid:3) 2(cid:3) (cid:4) 2(cid:3) 3 4 15 ml (1 tbs) 125 ml (1 2 c) 1 small (2(cid:3)) 1 (28 g) 750 ml (3 c) 7 30 15 ml (3 tsp or packets) i a p p e n d i x i-10 appendix i table i-2 food groups that contain little or no carbohydrate food measure vegetables: to encourage consumption, most vegetables are considered free asparagus beans, yellow or green bean sprouts beets broccoli cabbage carrots cauli ower celery cucumber eggplant greens leeks mushrooms okra parsnipsa peasa peppers rutabagas (turnips)a salad vegetables snow peas squash, wintera tomatoes meat and alternatives: 0 g carbohydrate, 7 g protein, 3 5 g fat, 307 kj (73 kcal) cheese, skim ((cid:5)7% milk fat) cheese, light ((cid:5)17% milk fat) 30 g (1 oz) 30 g (1 oz) cheese, regular (17 33% milk fat) cottage cheese (1 2% milk fat) egg fish, canned in oil fish, canned in water fish, fresh, cooked hummusb legumes, cookedb meat, game, cooked 30 g (1 oz) 50 ml (1 4 c) 1 large 50 ml (1 4 c) 50 ml (1 4 c) 30 g (1 oz) 1 3 c 125 ml (1 2 c) 30 g (1 oz) athese vegetables provide signi cant carbohydrate when more than 125 ml (1 2 c) is eaten. -blegumes contain 15 g carbohydrate in a 125 ml (1 2 c) serving. -(continued on the next page) i x i d n e p p a canada: guidelines and meal planning i-11 table i-2 food groups that contain little or no carbohydrate continued food measure meat and alternatives: 0 g carbohydrate, 7 g protein, 3 5 g fat, 307 kj (73 kcal) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 30 g (1 oz) 1 2 block (100 g) 30 g (1 oz) 1 6 30 g (1 oz) 5 ml (1 tsp) 15 ml (1 tbs) 5 ml (1 tsp) 30 ml (2 tbs) 15 ml (1 tbs) 5 ml (1 tsp) 15 ml (1 tbs) 15 ml (1 tbs) 7.5 ml (1 2 tbs) meat, ground, lean, cooked meat, ground, medium-regular, cooked meat, lean, cooked meat, organ or tripe, cooked meat, prepared, low fat meat, prepared, regular fat meat, regular, cooked peameal/back bacon, cooked poultry, ground, lean, cooked poultry, skinless, cooked poultry/wings, skin on, cooked shell sh, cooked tofu (soybean) vegetarian meat alternatives fats: 0 g carbohydrate, 0 g protein, 5 g fat, 189 kj (45 kcal) avocado bacon butter cheese, spreadable margarine, non-hydrogenated mayonnaise, light nuts oil, canola or olive salad dressing, regular seeds tahini extras: <5 g carbohydrate, 84 kj (20 kcal) broth coffee herbs and spices ketchup mustard sugar-free soft drinks sugar-free gelatin tea i a p p e n d i x this page intentionally left blank healthy people 2010 j-1 healthy people 2010 table 1-4 (p. 23) lists the objectives from the nutrition and overweight focus area of the healthy people 2010 initiative. -this table presents additional nutrition-related objectives from other focus areas. -table j-1 nutrition-related objectives from other focus areas access to quality health services increase the proportion of persons appropriately counseled about health behaviors. -arthritis, osteoporosis, and chronic back conditions reduce the proportion of adults with osteoporosis. -cancer reduce the overall cancer death rate. -reduce the breast cancer death rate. -reduce the colorectal cancer death rate. -increase the proportion of physicians and dentists who counsel their at-risk patients about tobacco- use cessation, physical activity, and cancer screening. -chronic kidney disease increase the proportion of treated chronic kidney failure patients who have received counseling on nutrition, treatment choices, and cardiovascular care 12 months before the start of renal replace- ment therapy. -diabetes increase the proportion of persons with diabetes who receive formal diabetes education. -prevent diabetes. -reduce diabetes-related deaths among persons with diabetes. -educational and community-based programs increase the proportion of middle, junior high, and senior high schools that provide school health education to prevent health problems in the following areas: unintentional injury; violence; suicide; tobacco use and addiction; alcohol and other drug use; unintended pregnancy, hiv/aids, and std infection; unhealthy dietary patterns; inadequate physical activity; and environmental health. -increase the proportion of worksites that offer a comprehensive employee health promotion pro- gram to their employees. -increase the proportion of employees who participate in employer-sponsored health promotion activities. -increase the proportion of community health promotion programs that address multiple healthy people 2010 focus areas. -increase the proportion of local health departments that have established culturally appropriate and linguistically competent community health promotion and disease prevention programs. -health communication increase the proportion of health-related world wide web sites that disclose information that can be used to assess the quality of the site. -heart disease and stroke reduce coronary heart disease deaths. -reduce stroke deaths. -reduce the proportion of adults with high blood pressure. -(continued) j a p p e n d i x table j-1 nutrition-related objectives from other focus areas continued heart disease and stroke, continued increase the proportion of adults with high blood pressure who are taking action (for example, losing weight, increasing physical activity, or reducing sodium intake) to help control their blood pressure. -reduce the mean total blood cholesterol levels among adults. -reduce the proportion of adults with high total blood cholesterol levels. -maternal, infant, and child health reduce low birth weight (lbw) and very low birthweight (vlbw). -increase the proportion of mothers who achieve a recommended weight gain during pregnancy. -reduce the occurrence of spina bi da and other neural tube defects. -increase the proportion of pregnancies begun with an optimum folate level. -increase abstinence from alcohol, cigarettes, and illicit drugs among pregnant women. -reduce the occurrence of fetal alcohol syndrome (fas). -increase the proportion of mothers who breastfeed their babies. -mental health and mental disorders reduce the relapse rates for persons with eating disorders, including anorexia nervosa and bulimia nervosa. -physical activity and fitness reduce the proportion of adults who engage in no leisure-time physical activity. -increase the proportion of adults who engage regularly, preferably daily, in moderate physical activity for at least 30 minutes per day. -increase the proportion of adults who engage in vigorous physical activity that promotes the devel- opment and maintenance of cardiorespiratory tness 3 or more days per week for 20 or more minutes per occasion. -increase the proportion of adolescents who engage in moderate physical activity for at least 30 minutes on 5 or more of the previous 7 days. -increase the proportion of adolescents who engage in vigorous physical activity that promotes cardiorespiratory tness 3 or more days per week for 20 or more minutes per occasion. -increase the proportion of adolescents who participate in daily school physical education. -increase the proportion of worksites offering employer-sponsored physical activity and tness programs. -substance abuse reduce average annual alcohol consumption. -source: adapted from healthy people 2010: www.healthypeople.gov j-2 appendix j j x i d n e p p a glossary general a- or an- = not or without ana- = up ant- or anti- = against ante- or pre- or pro- = before cata- = down co- = with or together bi- or di- = two, twice dys- or mal- = bad, difficult, painful endo- = inner or within epi- = upon exo- = outside of or without extra- = outside of, beyond, or in addition gen- or -gen = gives rise to, producing homeo- = like, similar, constant unchanging state hyper- = over, above, excessive hypo- = below, under, beneath in- = not inter- = between, in the midst intra- = within -itis = infection or inflammation -lysis = break macro- = large or long micro- = small mono- = one, single neo- = new, recent oligo- = few or small -osis or -asis = condition para- = near peri- = around, about poly- = many or much semi- = half -stat or -stasis- = stationary tri- = three body angi- or vaso- = vessel arterio- = artery cardiac or cardio- = heart -cyte = cell enteron = intestine gastro- = stomach hema- or -emia = blood hepatic = liver myo- or sarco- = muscle nephr- or renal = kidney neuro- = nerve osteo- = bone pulmo- = lung ure- or -uria = urine vena = vein chemistry -al = aldehyde -ase = enzyme -ate = salt glyc- or gluc- = sweet (glucose) hydro- or hydrate = water lipo- = lipid -ol = alcohol -ose = carbohydrate saccha- = sugar many medical terms have their origins in latin or greek. -by learning a few common derivations, you can glean the meaning of words you have never heard of before. -for example, once you know that hyper means above normal, glyc means glucose, and emia means blood, you can easily deter- mine that hyperglycemia means high blood glucose. -the derivations at left will help you to learn many terms presented in this glossary. -24-hour recall: a record of foods eaten by a person adequate intake (ai): the average daily amount of a for one 24-hour period. -a absorption: the uptake of nutrients by the cells of the small intestine for transport into either the blood or the lymph. -acceptable daily intake (adi): the estimated amount of a sweetener that individuals can safely consume each day over the course of a lifetime without adverse effect. -acceptable macronutrient distribution ranges (amdr): ranges of intakes for the energy nutrients that provide adequate energy and nutrients and reduce the risk of chronic diseases. -accredited: approved; in the case of medical centers or universities, certified by an agency recognized by the u.s. department of education. -acesulfame (ay-sul-fame) potassium: an artificial sweetener composed of an organic salt that has been approved for use in both the united states and canada; also known as acesulfame-k because k is the chemical symbol for potassium. -acetaldehyde (ass-et-al-duh-hide): an intermediate in alcohol metabolism. -acetyl coa (ass-eh-teel, or ah-seet-il, coh-ay): a 2- carbon compound (acetate, or acetic acid) to which a molecule of coa is attached. -acid controllers: medications used to prevent or relieve indigestion by suppressing production of acid in the stomach; also called h2 blockers. -acid-base balance: the equilibrium in the body between acid and base concentrations (see chapter 12). -acidosis (assi-doe-sis): above-normal acidity in the blood and body fluids. -acids: compounds that release hydrogen ions in a solution. -acne: a chronic inflammation of the skin s follicles and oil-producing glands, which leads to an accumulation of oils inside the ducts that surround hairs; usually associated with the maturation of young adults. -acupuncture (ak-you-punk-cher): a technique that involves piercing the skin with long thin needles at specific anatomical points to relieve pain or illness. -acute pem: protein-energy malnutrition caused by recent severe food restriction; characterized in children by thinness for height (wasting). -added sugars: sugars and syrups used as an ingredient in the processing and preparation of foods such as breads, cakes, beverages, jellies, and ice cream as well as sugars eaten separately or added to foods at the table. -adaptive thermogenesis: adjustments in energy expenditure related to changes in environment such as extreme cold and to physiological events such as overfeeding, trauma, and changes in hormone status. -additives: substances not normally consumed as foods but added to food either intentionally or by accident. -adequacy (dietary): providing all the essential nutrients, fiber, and energy in amounts sufficient to maintain health. -nutrient that appears sufficient to maintain a specified criterion; a value used as a guide for nutrient intake when an rda cannot be determined. -adipose (add-ih-poce) tissue: the body s fat tissue; consists of masses of triglyceride-storing cells. -adolescence: the period from the beginning of puberty until maturity. -adrenal glands: glands adjacent to, and just above, each kidney. -adrenocorticotropin (ad-ree-noh-kore-teeoh-trop- in) atch: a hormone, so named because it stimulates (trope) the adrenal cortex. -the adrenal gland, like the pituitary, has two parts, in this case the outer portion (cortex) and an inner core (medulla). -the release of acth is mediated by corticotropin-releasing hormone (crh). -adverse reactions: unusual responses to food (including intolerances and allergies). -aerobic (air-roe-bic): requiring oxygen. -agribusinesses: agriculture practiced on a massive scale by large corporations owning vast acreages and employing intensive technological, fuel, and chemical inputs. -aids (acquired immune deficiency syndrome): the late stage of hiv infection, in which severe complications develop. -alcohol: a class of organic compounds containing hydroxyl (oh) groups. -alcohol abuse: a pattern of drinking that includes failure to fulfill work, school, or home responsibilities; drinking in situations that are physically dangerous (as in driving while intoxicated); recurring alcohol-related legal problems (as in aggravated assault charges); or continued drinking despite ongoing social problems that are caused by or worsened by alcohol. -alcohol dehydrogenase (dee-high-droj-eh-nayz): an enzyme active in the stomach and the liver that converts ethanol to acetaldehyde. -alcoholism: a pattern of drinking that includes a strong craving for alcohol, a loss of control and an inability to stop drinking once begun, withdrawal symptoms (nausea, sweating, shakiness, and anxiety) after heavy drinking, and the need for increasing amounts of alcohol to feel high. -alcohol-related birth defects (arbd): malformations in the skeletal and organ systems (heart, kidneys, eyes, ears) associated with prenatal alcohol exposure. -alcohol-related neurodevelopmental disorder (arnd): abnormalities in the central nervous system and cognitive development associated with prenatal alcohol exposure. -aldosterone (al-dos-ter-own): a hormone secreted by the adrenal glands that regulates blood pressure by increasing the reabsorption of sodium by the kidneys. -aldosterone also regulates chloride and potassium concentrations. -alitame (al-ih-tame): an artificial sweetener composed of two amino acids (alanine and aspartic acid); fda approval pending. -alkalosis (alka-loe-sis): above-normal alkalinity (base) in the blood and body fluids. -gl-1 gl-2 glossary alpha-lactalbumin (lact-al-byoo-min): a major anions (an-eye-uns): negatively charged ions. --ase (ace): a word ending denoting an enzyme. -protein in human breast milk, as opposed to casein (cay-seen), a major protein in cow s milk. -alpha-tocopherol: the active vitamin e compound. -alzheimer s disease: a degenerative disease of the brain involving memory loss and major structural changes in neuron networks; also known as senile dementia of the alzheimer s type (sdat), primary degenerative dementia of senile onset, or chronic brain syndrome. -amenorrhea (ay-men-oh-ree-ah): the absence of or cessation of menstruation. -primary amenorrhea is menarche delayed beyond 16 years of age. -secondary amenorrhea is the absence of three to six consecutive menstrual cycles. -american dietetic association (ada): the professional organization of dietitians in the united states. -the canadian equivalent is dietitians of canada, which operates similarly. -amino (a-meen-oh) acids: building blocks of proteins. -each contains an amino group, an acid group, a hydrogen atom, and a distinctive side group, all attached to a central carbon atom. -amino acid pool: the supply of amino acids derived from either food proteins or body proteins that collect in the cells and circulating blood and stand ready to be incorporated in proteins and other compounds or used for energy. -amino acid scoring: a measure of protein quality assessed by comparing a protein s amino acid pattern with that of a reference protein; sometimes called chemical scoring. -ammonia: a compound with the chemical formula nh3; produced during the deamination of amino acids. -amniotic (am-nee-ott-ic) sac: the bag of waters in anorexia (an-oh-reck-see-ah) nervosa: an eating disorder characterized by a refusal to maintain a minimally normal body weight and a distortion in perception of body shape and weight. -antacids: medications used to relieve indigestion by neutralizing acid in the stomach. -antagonist: a competing factor that counteracts the action of another factor. -anthropometric (an-throw-poe-met-rick): relating to measurement of the physical characteristics of the body, such as height and weight. -antibodies: large proteins of the blood and body fluids, produced by the immune system in response to the invasion of the body by foreign molecules (usually proteins called antigens). -antidiuretic hormone (adh): a hormone produced by the pituitary gland in response to dehydration (or a high sodium concentration in the blood). -it stimulates the kidneys to reabsorb more water and therefore prevents water loss in urine (also called vasopressin). -antigens: substances that elicit the formation of antibodies or an inflammation reaction from the immune system. -antioxidant: in the human body, a substance that significantly decreases the adverse effects of free radicals on normal physiological functions. -antioxidants: as a food additive, preservatives that delay or prevent rancidity of fats in foods and other damage to food caused by oxygen. -antipromoters: factors that oppose the development of cancer. -antiscorbutic (an-tee-skor-bue-tik) factor: the original name for vitamin c. the uterus, in which the fetus floats. -anus (ay-nus): the terminal outlet of the gi tract. -amylase (am-ih-lace): an enzyme that hydrolyzes aorta (ay-or-tuh): the large, primary artery that amylose (a form of starch). -amylase is a carbohydrase, an enzyme that breaks down carbohydrates. -anabolic steroids: drugs related to the male sex hormone, testosterone, that stimulate the development of lean body mass. -anabolism (an-ab-o-lism): reactions in which small molecules are put together to build larger ones. -anabolic reactions require energy. -anaerobic (an-air-roe-bic): not requiring oxygen. -anaphylactic (ana- fill-lac-tic) shock: a life- threatening, whole-body allergic reaction to an offending substance. -anemia (ah-nee-me-ah): literally, too little blood. -anemia is any condition in which too few red blood cells are present, or the red blood cells are immature (and therefore large) or too small or contain too little hemoglobin to carry the normal amount of oxygen to the tissues. -it is not a disease itself but can be a symptom of many different disease conditions, including many nutrient deficiencies, bleeding, excessive red blood cell destruction, and defective red blood cell formation. -anencephaly (an-en-sef-a-lee): an uncommon and always fatal type of neural tube defect; characterized by the absence of a brain. -aneurysm (an-you-rizm): an abnormal enlargement or bulging of a blood vessel (usually an artery) caused by damage to or weakness in the blood vessel wall. -angina (an-jye-nah or an-ji-nah): a painful feeling of tightness or pressure in and around the heart, often radiating to the back, neck, and arms; caused by a lack of oxygen to an area of heart muscle. -angiotensin (an-gee-oh-ten-sin): a hormone involved in blood pressure regulation. -its precursor protein is called angiotensinogen; it is activated by renin, an enzyme from the kidneys. -conducts blood from the heart to the body s smaller arteries. -appendix: a narrow blind sac extending from the beginning of the colon that stores lymph cells. -appetite: the integrated response to the sight, smell, thought, or taste of food that initiates or delays eating. -arachidonic (a-rack-ih-don-ic) acid: an omega-6 polyunsaturated fatty acid with 20 carbons and four double bonds; present in small amounts in meat and other animal products and synthesized in the body from linoleic acid. -arginine: a nonessential amino acid falsely promoted as enhancing the secretion of human growth hormone, the breakdown of fat, and the development of muscle. -aroma therapy: a technique that uses oil extracts from plants and flowers (usually applied by massage or baths) to enhance physical, psychological, and spiritual health. -arteries: vessels that carry blood from the heart to the tissues. -artesian water: water drawn from a well that taps a confined aquifer in which the water is under pressure. -arthritis: inflammation of a joint, usually accompanied by pain, swelling, and structural changes. -artificial fats: zero-energy fat replacers that are chemically synthesized to mimic the sensory and cooking qualities of naturally occurring fats but are totally or partially resistant to digestion. -artificial sweeteners: sugar substitutes that provide negligible, if any, energy; sometimes called nonnutritive sweeteners. -ascorbic acid: one of the two active forms of vitamin c. the word beginning often identifies the compounds the enzyme works on. -aspartame (ah-spar-tame or ass-par-tame): an artificial sweetener composed of two amino acids (phenylalanine and aspartic acid); approved for use in both the united states and canada. -atherosclerosis (ath-er-oh-scler-oh-sis): a type of artery disease characterized by placques (accumulations of lipid-containing material) on the inner walls of the arteries (see chapter 18). -atoms: the smallest components of an element that have all of the properties of the element. -atp or adenosine (ah-den-oh-seen) triphosphate (try-fos-fate): a common high-energy compound composed of a purine (adenine), a sugar (ribose), and three phosphate groups. -atrophic (a-tro-fik) gastritis (gas-try-tis): chronic inflammation of the stomach accompanied by a diminished size and functioning of the mucous membrane and glands. -atrophy (at-ro-fee): becoming smaller; with regard to muscles, a decrease in size (and strength) because of disuse, undernutrition, or wasting diseases. -autoimmune disorder: a condition in which the body develops antibodies to its own proteins and then proceeds to destroy cells containing these proteins. -in type 1 diabetes, the body develops antibodies to its insulin and destroys the pancreatic cells that produce the insulin, creating an insulin deficiency. -autonomic nervous system: the division of the nervous system that controls the body s automatic responses. -its two branches are the sympathetic branch, which helps the body respond to stressors from the outside environment, and the parasympathetic branch, which regulates normal body activities between stressful times. -ayurveda (ah-your-vay-dah): a traditional hindu system of improving health by using herbs, diet, meditation, massage, and yoga to stimulate the body, mind, and spirit to prevent and treat disease. -b balance (dietary): providing foods in proportion to each other and in proportion to the body s needs. -basal metabolic rate (bmr): the rate of energy use for metabolism under specified conditions: after a 12-hour fast and restful sleep, without any physical activity or emotional excitement, and in a comfortable setting. -it is usually expressed as kcalories per kilogram body weight per hour. -basal metabolism: the energy needed to maintain life when a body is at complete digestive, physical, and emotional rest. -bases: compounds that accept hydrogen ions in a solution. -b-cells: lymphocytes that produce antibodies. -b stands for bone marrow where the b-cells develop and mature. -beer: an alcoholic beverage brewed by fermenting malt and hops. -behavior modification: the changing of behavior by the manipulation of antecedents (cues or environmental factors that trigger behavior), the behavior itself, and consequences (the penalties or rewards attached to behavior). -belching: the expulsion of gas from the stomach through the mouth. -beriberi: the thiamin-deficiency disease. -beta-carotene (bay-tah kare-oh-teen): one of the carotenoids; an orange pigment and vitamin a precursor found in plants. -bone density: a measure of bone strength. -when carbohydrates: compounds composed of carbon, glossary gl-3 bha and bht: preservatives commonly used to slow the development of off-flavors, odors, and color changes caused by oxidation. -minerals fill the bone matrix (making it dense), they give it strength. -bicarbonate: an alkaline compound with the formula hco3 that is secreted from the pancreas as part of the pancreatic juice. -(bicarbonate is also produced in all cell fluids from the dissociation of cabonic acid to help maintain the body s acid-base balance.) -bone meal or powdered bone: crushed or ground bone preparations intended to supply calcium to the diet. -calcium from bone is not well absorbed and is often contaminated with toxic minerals such as arsenic, mercury, lead, and cadmium. -bifidus (biff-id-us, by-feed-us) factors: factors in boron: a nonessential mineral that is promoted to colostrum and breast milk that favor the growth of the friendly bacterium lactobacillus (lack-toh-ba-sill-us) bifidus in the infant s intestinal tract, so that other, less desirable intestinal inhabitants will not flourish. -bile: an emulsifier that prepares fats and oils for digestion; an exocrine secretion made by the liver, stored in the gallbladder, and released into the small intestine when needed. -binders: chemical compounds in foods that combine with nutrients (especially minerals) to form complexes the body cannot absorb. -examples include phytates (fye-tates) and oxalates (ock-sa-lates). -binge-eating disorder: an eating disorder with criteria similar to those of bulimia nervosa, excluding purging or other compensatory behaviors. -bioaccumulation: the accumulation of contaminants in the flesh of animals high on the food chain. -bioavailability: the rate at and the extent to which a nutrient is absorbed and used. -bioelectromagnetic medical applications: the use of electrical energy, magnetic energy, or both to stimulate bone repair, wound healing, and tissue regeneration. -biofeedback: the use of special devices to convey information about heart rate, blood pressure, skin temperature, muscle relaxation, and the like to enable a person to learn how to consciously control these medically important functions. -biofield therapeutics: a manual healing method that directs a healing force from an outside source (commonly god or another supernatural being) through the practitioner and into the client s body; commonly known as laying on of hands. -biological value (bv): a measure of protein quality assessed by measuring the amount of protein nitrogen that is retained from a given amount of protein nitrogen absorbed. -biotechnology: the use of biological systems or organisms to create or modify products. -examples include the use of bacteria to make yogurt, yeast to make beer, and cross-breeding to enhance crop production. -bioterrorism: the intentional spreading of disease- causing microorganisms or toxins. -biotin (by-oh-tin): a b vitamin that functions as a coenzyme in metabolism. -blind experiment: an experiment in which the subjects do not know whether they are members of the experimental group or the control group. -blood lipid profile: results of blood tests that reveal a person s total cholesterol, triglycerides, and various lipoproteins. -body composition: the proportions of muscle, bone, fat, and other tissue that make up a person s total body weight. -body mass index (bmi): an index of a person s weight in relation to height; determined by dividing the weight (in kilograms) by the square of the height (in meters). -bolus (boh-lus): a portion; with respect to food, the amount swallowed at one time. -bomb calorimeter (kal-oh-rim-eh-ter): an instrument that measures the heat energy released when foods are burned, thus providing an estimate of the potential energy of the foods. -increase muscle mass. -bottled water: drinking water sold in bottles. -botulism (bot-chew-lism): an often fatal foodborne illness caused by the ingestion of foods containing a toxin produced by bacteria that grow without oxygen. -bovine growth hormone (bgh): a hormone produced naturally in the pituitary gland of a cow that promotes growth and milk production; now produced for agricultural use by bacteria. -branched-chain amino acids: the essential amino acids leucine, isoleucine, and valine, which are present in large amounts in skeletal muscle tissue; falsely promoted as fuel for exercising muscles. -breast milk bank: a service that collects, screens, processes, and distributes donated human milk. -brown adipose tissue: masses of specialized fat cells packed with pigmented mitochondria that produce heat instead of atp. -brown sugar: refined white sugar crystals to which manufacturers have added molasses syrup with natural flavor and color; 91 to 96% pure sucrose. -bulimia (byoo-leem-ee-ah) nervosa: an eating disorder characterized by repeated episodes of binge eating usually followed by self-induced vomiting, misuse of laxatives or diuretics, fasting, or excessive exercise. -c caffeine: a natural stimulant found in many common foods and beverages, including coffee, tea, and chocolate; may enhance endurance by stimulating fatty acid release. -high doses cause headaches, trembling, rapid heart rate, and other undesirable side effects. -calcitonin (kal-seh-toe-nin): a hormone secreted by the thyroid gland that regulates blood calcium by lowering it when levels rise too high. -calcium: the most abundant mineral in the body; found primarily in the body s bones and teeth. -calcium rigor: hardness or stiffness of the muscles caused by high blood calcium concentrations. -calcium tetany (tet-ah-nee): intermittent spasm of the extremities due to nervous and muscular excitability caused by low blood calcium concentrations. -calcium-binding protein: a protein in the intestinal cells, made with the help of vitamin d, that facilitates calcium absorption. -calories: units by which energy is measured. -food energy is measured in kilocalories (1000 calories equal 1 kilocalorie), abbreviated kcalories or kcal. -one kcalorie is the amount of heat necessary to raise the temperature of 1 kilogram (kg) of water 1 c. cancers: malignant growths or tumors that result from abnormal and uncontrolled cell division. -capillaries (cap-ill-aries): small vessels that branch from an artery. -capillaries connect arteries to veins. -exchange of oxygen, nutrients, and waste materials takes place across capillary walls. -carbohydrate loading: a regimen of moderate exercise followed by the consumption of a high- carbohydrate diet that enables muscles to store glycogen beyond their normal capacities; also called glycogen loading or glycogen super compensation. -oxygen, and hydrogen arranged as monosaccharides or multiples of monosaccharides. -most, but not all, carbohydrates have a ratio of one carbon molecule to one water molecule: (ch2o)n. carbonated water: water that contains carbon dioxide gas, either naturally occurring or added, that causes bubbles to form in it; also called bubbling or sparkling water. -carbonic acid: a compound with the formula h2co3 that results from the combination of carbon dioxide (co2) and water (h2o); of particular importance in maintaining the body s acid-base balance. -carcinogenesis (car-sin-oh-jen-eh-sis): the process of cancer development. -carcinogens (car-sin-oh-jenz or car-sin-oh-jenz): substances that can cause cancer (the adjective is carcinogenic). -cardiac output: the volume of blood discharged by the heart each minute; determined by multiplying the stroke volume by the heart rate. -the stroke volume is the amount of oxygenated blood the heart ejects toward the tissues at each beat. -cardiorespiratory conditioning: improvements in heart and lung function and increased blood volume, brought about by aerobic training. -cardiorespiratory endurance: the ability to perform large-muscle, dynamic exercise of moderate-to-high intensity for prolonged periods. -cardiovascular disease (cvd): a general term for all diseases of the heart and blood vessels. -atherosclerosis is the main cause of cvd. -when the arteries that carry blood to the heart muscle become blocked, the heart suffers damage known as coronary heart disease (chd). -carnitine (car-neh-teen): a nonessential, nonprotein amino acid made in the body from lysine that helps transport fatty acids across the mitochondrial membrane. -carotenoids (kah-rot-eh-noyds): pigments commonly found in plants and animals, some of which have vitamin a activity. -the carotenoid with the greatest vitamin a activity is beta-carotene. -carpal tunnel syndrome: a pinched nerve at the wrist, causing pain or numbness in the hand. -it is often caused by repetitive motion of the wrist. -cartilage therapy: the use of cleaned and powdered connective tissue, such as collagen, to improve health. -catabolism (ca-tab-o-lism): reactions in which large molecules are broken down to smaller ones. -catabolic reactions release energy. -catalyst (cat-uh-list): a compound that facilitates chemical reactions without itself being changed in the process. -cataracts (kat-ah-rakts): thickenings of the eye lenses that impair vision and can lead to blindness. -cathartic (ka-thar-tik): a strong laxative. -cations (cat-eye-uns): positively charged ions. -cdc (centers for disease control): a branch of the department of health and human services that is responsible for, among other things, monitoring foodborne diseases. -cell: the basic structural unit of all living things. -cell differentiation (dif-er-en-she-ay-shun): the process by which immature cells develop specific functions different from those of the original that are characteristic of their mature cell type. -cell membrane: the thin layer of tissue that surrounds the cell and encloses its contents; made primarily of lipid and protein. -cellulite (sell-you-light or sell-you-leet): supposedly, a lumpy form of fat; actually, a fraud. -fatty areas of the body may appear lumpy when chylomicrons (kye-lo-my-cronz): the class of contaminants: substances that make a food impure certification: the process in which a private clinically severe obesity: a bmi of 40 or greater or a gl-4 glossary the strands of connective tissue that attach the skin to underlying muscles pull tight where the fat is thick. -the fat itself is the same as fat anywhere else in the body. -if the fat in these areas is lost, the lumpy appearance disappears. -central nervous system: the central part of the nervous system; the brain and spinal cord. -central obesity: excess fat around the trunk of the body; also called abdominal fat or upper-body fat. -laboratory inspects shipments of a product for selected chemicals and then, if the product is free of violative levels of those chemicals, issues a guarantee to that effect. -certified nutritionists or certified nutritional consultants or certified nutrition therapists: a person who has been granted a document declaring his or her authority as a nutrition professional. -cesarean section: a surgically assisted birth involving removal of the fetus by an incision into the uterus, usually by way of the abdominal wall. -chd risk equivalents: disorders that raise the risk of heart attacks, strokes, and other complications associated with cardiovascular disease to the same degree as existing chd. -these disorders include symptomatic carotid artery disease, peripheral arterial disease, abdominal aortic aneurysm, and diabetes mellitus. -chelate (key-late): a substance that can grasp the positive ions of a mineral. -chelation (kee-lay-shun) therapy: the use of ethylene diamine tetraacetic acid (edta) to bind with metallic ions, thus healing the body by removing toxic metals. -chiropractic (kye-roh-prak-tik): a manual healing method of manipulating the spine to restore health. -chloride (klo-ride): the major anion in the extracellular fluids of the body. -chloride is the ionic form of chlorine, cl(cid:2). -chlorophyll (klo-row-fil): the green pigment of plants, which absorbs light and transfers the energy to other molecules, thereby initiating photosynthesis. -cholecystokinin (coal-ee-sis-toe-kine-in), or cck: a hormone produced by cells of the intestinal wall. -target organ: the gallbladder. -response: release of bile and slowing of gi motility. -cholesterol (koh-less-ter-ol): one of the sterols containing a four ring carbon structure with a carbon side chain. -cholesterol-free: less than 2 mg cholesterol per serving and 2 g or less saturated fat and trans fat combined per serving. -choline (koh-leen): a nitrogen-containing compound found in foods and made in the body from the amino acid methionine. -choline is part of the phospholipid lecithin and the neurotransmitter acetylcholine. -chromium picolinate (crow-mee-um pick-oh-lyn- ate): a trace mineral supplement; falsely promoted as building muscle, enhancing energy, and burning fat. -picolinate is a derivative of the amino acid tryptophan that seems to enhance chromium absorption. -lipoproteins that transport lipids from the intestinal cells to the rest of the body. -chyme (kime): the semiliquid mass of partly digested food expelled by the stomach into the duodenum. -cirrhosis (seer-oh-sis): advanced liver disease in which liver cells turn orange, die, and harden, permanently losing their function; often associated with alcoholism. -bmi of 35 or greater with additional medical problems. -a less preferred term used to describe the same condition is morbid obesity. -coa (coh-ay): coenzyme a; the coenzyme derived from the b vitamin pantothenic acid and central to energy metabolism. -coenzyme q10: a lipid found in cells (mitochondria) shown to improve exercise performance in heart disease patients, but not effective in improving the performance of healthy athletes. -coenzymes: complex organic molecules that work with enzymes to facilitate the enzymes activity. -many coenzymes have b vitamins as part of their structures. -colitis (ko-lye-tis): inflammation of the colon. -collagen (kol-ah-jen): the protein from which connective tissues such as scars, tendons, ligaments, and the foundations of bones and teeth are made. -colonic irrigation: the popular, but potentially harmful practice of washing the large intestine with a powerful enema machine. -colostrum (ko-lahs-trum): a milklike secretion from the breast, present during the first day or so after delivery before milk appears; rich in protective factors. -complementary and alternative medicine (cam): diverse medical and health care systems, practices, and products that are not currently considered part of conventional medicine; also called adjunctive, unconventional, or unorthodox therapies. -complementary medicine: an approach that uses alternative therapies as an adjunct to, and not simply a replacement for, conventional medicine. -complementary proteins: two or more dietary proteins whose amino acid assortments complement each other in such a way that the essential amino acids missing from one are supplied by the other. -complex carbohydrates (starches and fibers): polysaccharides composed of straight or branched chains of monosaccharides. -compound: a substance composed of two or more different atoms for example, water (h2o). -conception: the union of the male sperm and the female ovum; fertilization. -condensation: a chemical reaction in which two reactants combine to yield a larger product. -that is normally nonessential, but must be supplied by the diet in special circumstances when the need for it exceeds the body s ability to produce it. -conditioning: the physical effect of training; improved flexibility, strength, and endurance. -chromosomes: structures within the nucleus of a cell confectioners sugar: finely powdered sucrose, made of dna and associated proteins. -human beings have 46 chromosomes in 23 pairs. -each chromosome has many genes. -chronic diseases: diseases characterized by a slow progression and long duration. -chronic pem: protein-energy malnutrition caused by long-term food deprivation; characterized in children by short height for age (stunting). -99.9% pure. -congregate meals: nutrition programs that provide food for the elderly in conveniently located settings such as community centers. -conjugated linoleic acid: a collective term for several fatty acids that have the same chemical formula as linoleic acid (18 carbons, two double bonds) but with different configurations. -chronological age: a person s age in years from his or constipation: the condition of having infrequent or her date of birth. -difficult bowel movements. -and unsuitable for ingestion. -contamination iron: iron found in foods as the result of contamination by inorganic iron salts from iron cookware, iron-containing soils, and the like. -control group: a group of individuals similar in all possible respects to the experimental group except for the treatment. -ideally, the control group receives a placebo while the experimental group receives a real treatment. -conventional medicine: diagnosis and treatment of diseases as practiced by medical doctors (m.d.) -and doctors of osteopathy (d.o.) -and allied health professionals such as physical therapists and registered nurses; also called allopathy; western, mainstream, orthodox, or regular medicine; and biomedicine. -cool-down: 5 to 10 minutes of light activity, such as walking or stretching, following a vigorous workout to gradually return the body s core to near-normal temperature. -cori cycle: the path from muscle glycogen to glucose to pyruvate to lactate (which travels to the liver) to glucose (which can travel back to the muscle) to glycogen; named after the scientist who elucidated this pathway. -corn sweeteners: corn syrup and sugars derived from corn. -corn syrup: a syrup made from cornstarch that has been treated with acid, high temperatures, and enzymes that produce glucose, maltose, and dextrins. -see also high-fructose corn syrup (hfcs). -cornea (kor-nee-uh): the transparent membrane covering the outside of the eye. -coronary arteries: blood vessels that supply blood to the heart. -coronary heart disease (chd): the damage that occurs when the blood vessels carrying blood to the heart (the coronary arteries) become narrow and occluded. -correlation (core-ee-lay-shun): the simultaneous increase, decrease, or change in two variables. -if a increases as b increases, or if a decreases as b decreases, the correlation is positive. -(this does not mean that a causes b or vice versa.) -if a increases as b decreases, or if a decreases as b increases, the correlation is negative. -(this does not mean that a prevents b or vice versa.) -some third factor may account for both a and b. correspondence schools: schools that offer courses and degrees by mail. -some correspondence schools are accredited; others are not. -cortical bone: the very dense bone tissue that forms the outer shell surrounding trabecular bone and comprises the shaft of a long bone. -coupled reactions: pairs of chemical reactions in which some of the energy released from the breakdown of one compound is used to create a bond in the formation of another compound. -cp, creatine phosphate (also called phosphocreatine): a high-energy compound in muscle cells that acts as a reservoir of energy that can maintain a steady supply of atp. -cp provides the energy for short bursts of activity. -c-reactive protein (crp): a protein released during the acute phase of infection or inflammation that enhances immunity by promoting phagocytosis and activating platelets. -its presence may be used to assess a person s risk of an impending heart attack or stroke. -creatine (kree-ah-tin): a nitrogen-containing compound that combines with phosphate to form the high-energy compound creatine phosphate (or phosphocreatine) in muscles. -claims that creatine enhances energy use and muscle strength need further confirmation. -conditionally essential amino acid: an amino acid covert (koh-vert): hidden, as if under covers. -cretinism (cree-tin-ism): a congenital disease characterized by mental and physical retardation and commonly caused by maternal iodine deficiency during pregnancy. -digestive enzymes, although some are digested by gi tract bacteria. -dietary fibers include cellulose, hemicelluloses, pectins, gums, and mucilages and the nonpolysaccharides lignins, cutins, and tannins. -critical periods: finite periods during development in which certain events occur that will have irreversible effects on later developmental stages; usually a period of rapid cell division. -dietary folate equivalents (dfe): the amount of folate available to the body from naturally occurring sources, fortified foods, and supplements, accounting for differences in the bioavailability from each source. -glossary gl-5 marble. -dolomite is powdered and is sold as a calcium-magnesium supplement. -however, it may be contaminated with toxic minerals, is not well absorbed, and interacts adversely with absorption of other esssential minerals. -double-blind experiment: an experiment in which neither the subjects nor the researchers know which subjects are members of the experimental group and which are serving as control subjects, until after the experiment is over. -down syndrome: a genetic abnormality that causes mental retardation, short stature, and flattened facial features. -drink: a dose of any alcoholic beverage that delivers 1 2 oz of pure ethanol: 5 oz of wine 10 oz of wine cooler 12 oz of beer drug: a substance that can modify one or more of the body s functions. -drug history: a record of all the drugs, over-the-counter and prescribed, that a person takes routinely. -dtr: see dietetic technician, registered. -duodenum (doo-oh-deen-um, doo-odd-num): the top portion of the small intestine (about 12 fingers breadth long in ancient terminology). -duration: length of time (for example, the time spent dietary reference intakes (dri): a set of nutrient intake values for healthy people in the united states and canada. -these values are used for planning and assessing diets and include: estimated average requirements (ear) recommended dietary allowances (rda) adequate intakes (ai) tolerable upper intake levels (ul) dietetic technician: a person who has completed a minimum of an associate s degree from an accredited university or college and an approved dietetic technician program that includes a supervised practice experience. -see also dietetic technician, registered (dtr). -dietetic technician, registered (dtr): a dietetic technician who has passed a national examination and maintains registration through continuing professional education. -dietitian: a person trained in nutrition, food science, and diet planning. -see also registered dietitian. -digestion: the process by which food is broken down in each activity session). -into absorbable units. -digestive enzymes: proteins found in digestive juices that act on food substances, causing them to break down into simpler compounds. -digestive system: all the organs and glands associated with the ingestion and digestion of food. -dioxins (dye-ock-sins): a class of chemical pollutants created as by-products of chemical manufacturing, incineration, chlorine bleaching of paper pulp, and other industrial processes. -dioxins persist in the environment and accumulate in the food chain. -dipeptide (dye-pep-tide): two amino acids bonded together. -disaccharides (dye-sack-uh-rides): pairs of monosaccharides linked together. -discretionary kcalorie allowance: the kcalories remaining in a person s energy allowance after consuming enough nutrient-dense foods to meet all nutrient needs for a day. -disordered eating: eating behaviors that are neither normal nor healthy, including restrained eating, fasting, binge eating, and purging. -dissociates (dis-so-see-aites): physically separates. -distilled liquor or hard liquor: an alcoholic beverage made by fermenting and distilling grains; sometimes called distilled spirits. -distilled water: water that has been vaporized and recondensed, leaving it free of dissolved minerals. -diverticula (dye-ver-tic-you-la): sacs or pouches that develop in the weakened areas of the intestinal wall (like bulges in an inner tube where the tire wall is weak). -diverticulitis (dye-ver-tic-you-lye-tis): infected or inflamed diverticula. -diverticulosis (dye-ver-tic-you-loh-sis): the condition of having diverticula. -dna (deoxyribonucleic acid): the double helix molecules of which genes are made. -docosahexaenoic (doe-cossa-hexa-ee-no-ick) acid (dha): an omega-3 polyunsaturated fatty acid with 22 carbons and six double bonds; present in fish and synthesized in limited amounts in the body from linolenic acid. -dolomite: a compound of minerals (calcium magnesium carbonate) found in limestone and dysentery (diss-en-terry): an infection of the digestive tract that causes diarrhea. -dysphagia (dis-fay-jah): difficulty in swallowing. -e eating disorders: disturbances in eating behavior that jeopardize a person s physical or psychological health. -eclampsia (eh-klamp-see-ah): a severe stage of preeclampsia characterized by convulsions. -edema (eh-deem-uh): the swelling of body tissue caused by excessive amounts of fluid in the interstitial spaces; seen in protein deficiency (among other conditions). -eicosanoids (eye-coss-uh-noyds): derivatives of 20- carbon fatty acids; biologically active compounds that help to regulate blood pressure, blood clotting, and other body functions. -they include prostaglandins (pros-tah-gland-ins), thromboxanes (throm-box-ains), and leukotrienes (loo-ko-try-eens). -eicosapentaenoic (eye-cossa-penta-ee-no-ick) acid (epa): an omega-3 polyunsaturated fatty acid with 20 carbons and five double bonds; present in fish and synthesized in limited amounts in the body from linolenic acid. -electrolyte solutions: solutions that can conduct electricity. -electrolytes: salts that dissolve in water and dissociate into charged particles called ions. -electron transport chain: the final pathway in energy metabolism that transports electrons from hydrogen to oxygen and captures the energy released in the bonds of atp. -element: a substance composed of atoms that are alike for example, iron (fe). -embolism (em-boh-lizm): the obstruction of a blood vessel by an embolus (em-boh-luss), or traveling clot, causing sudden tissue death. -embryo (em-bree-oh): the developing infant from two to eight weeks after conception. -emergency shelters: facilities that are used to provide temporary housing. -emerging risk factors: recently identified factors that enhance the ability to predict disease risk in an individual. -emetic (em-ett-ic): an agent that causes vomiting. -cross-contamination: the contamination of food by bacteria that occurs when the food comes into contact with surfaces previously touched by raw meat, poultry, or seafood. -cruciferous vegetables: vegetables of the cabbage family, including cauliflower, broccoli, and brussels sprouts. -crypts (kripts): tubular glands that lie between the intestinal villi and secrete intestinal juices into the small intestine. -cyclamate (sigh-kla-mate): an artificial sweetener that is being considered for approval in the united states and is available in canada as a tabletop sweetener, but not as an additive. -cytokines (sigh-toe-kines): special proteins that direct immune and inflammatory responses. -cytoplasm (sigh-toh-plazm): the cell contents, except for the nucleus. -cytosol: the fluid of cytoplasm; contains water, ions, nutrients, and enzymes. -d daily values (dv): reference values developed by the fda specifically foruse on food labels. -deamination (dee-am-ih-nay-shun): removal of the amino (nh2) group from a compound such as an amino acid. -defecate (def-uh-cate): to move the bowels and eliminate waste. -deficient: the amount of a nutrient below which almost all healthy people can be expected, over time, to experience deficiency symptoms. -dehydration: the condition in which body water output exceeds water input. -symptoms include thirst, dry skin and mucous membranes, rapid heartbeat, low blood pressure, and weakness. -delaney clause: a clause in the food additive amendment to the food, drug, and cosmetic act that states that no substance that is known to cause cancer in animals or human beings at any dose level shall be added to foods. -denaturation (dee-nay-chur-ay-shun): the change in a protein s shape and consequent loss of its function brought about by heat, agitation, acid, base, alcohol, heavy metals, or other agents. -dental caries: decay of teeth. -dental plaque: a gummy mass of bacteria that grows on teeth and can lead to dental caries and gum disease. -dextrose: an older name for glucose. -dhea (dehydroepiandrosterone) and androstenedione: hormones made in the adrenal glands that serve as precursors to the male hormone testosterone; falsely promoted as burning fat, building muscle, and slowing aging. -side effects include acne, aggressiveness, and liver enlargement. -diabetes (dye-uh-beet-eez): a chronic disorder of carbohydrate metabolism, usually resulting from insufficient or ineffective insulin. -diarrhea: the frequent passage of watery bowel movements. -diet: the foods and beverages a person eats and drinks. -diet history: a record of eating behaviors and the foods a person eats. -dietary fibers: in plant foods, the nonstarch polysaccharides that are not digested by human gl-6 glossary empty-kcalorie foods: a popular term used to denote esophagus (ee-soff-ah-gus): the food pipe; the fat-free: less than 0.5 g of fat per serving (and no foods that contribute energy but lack protein, vitamins, and minerals. -emulsifier (ee-mul-sih-fire): a substance with both water-soluble and fat-soluble portions that promotes the mixing of oils and fats in a watery solution. -endoplasmic reticulum (en-doh-plaz-mic reh-tic- you-lum): a complex network of intracellular membranes. -the rough endoplasmic reticulum is dotted with ribosomes, where protein synthesis takes place. -the smooth endoplasmic reticulum bears no ribosomes. -enemas: solutions inserted into the rectum and colon to stimulate a bowel movement and empty the lower large intestine. -energy: the capacity to do work. -the energy in food is chemical energy. -the body can convert this chemical energy to mechanical, electrical, or heat energy. -energy density: a measure of the energy a food provides relative to the amount of food (kcalories per gram). -energy-yielding nutrients: the nutrients that break down to yield energy the body can use. -enriched: the addition to a food of nutrients that were lost during processing so that the food will meet a specified standard. -enteropancreatic (en-ter-oh-pan-kree-at-ik) circulation: the circulatory route from the pancreas to the intestine and back to the pancreas. -enzymes: proteins that facilitate chemical reactions without being changed in the process; protein catalysts. -epa (environmental protection agency): a federal agency that is responsible for, among other things, regulating pesticides and establishing water quality standards. -epidemic (ep-ih-dem-ick): the appearance of a disease (usually infectious) or condition that attacks many people at the same time in the same region. -epigenetics: the study of heritable changes in gene function that occur without a change in the dna sequence. -epiglottis (epp-ih-glott-iss): cartilage in the throat that guards the entrance to the trachea and prevents fluid or food from entering it when a person swallows. -epinephrine (ep-ih-neff-rin): a hormone of the adrenal gland that modulates the stress response; formerly called adrenaline. -when administered by injection, epinephrine counteracts anaphylactic shock by opening the airways and maintaining heartbeat and blood pressure. -epithelial (ep-i-thee-lee-ul) cells: cells on the surface of the skin and mucous membranes. -epithelial tissue: the layer of the body that serves as a selective barrier between the body s interior and the environment. -(examples are the cornea of the eyes, the skin, the respiratory lining of the lungs, and the lining of the digestive tract.) -ergogenic (er-go-jen-ick) aids: substances or techniques used in an attempt to enhance physical performance. -erythrocyte (eh-rith-ro-cite) hemolysis (he-moll- uh-sis): the breaking open of red blood cells (erythrocytes); a symptom of vitamin e deficiency disease in human beings. -erythrocyte protoporphyrin (pro-toe-pore-fe-rin): a precursor to hemoglobin. -erythropoietin (eh-rith-ro-poy-eh-tin): a hormone that stimulates red blood cell production. -esophageal (ee-sof-ah-gee-al) sphincter: a sphincter muscle at the upper or lower end of the esophagus. -the lower esophageal sphincter is also called the cardiac sphincter. -conduit from the mouth to the stomach. -essential amino acids: amino acids that the body cannot synthesize in amounts sufficient to meet physiological needs (see table 6-1 on p. 182). -essential fatty acids: fatty acids needed by the body but not made by it in amounts sufficient to meet physiological needs. -essential nutrients: nutrients a person must obtain from food because the body cannot make them for itself in sufficient quantity to meet physiological needs; also called indispensable nutrients. -about 40 nutrients are currently known to be essential for human beings. -estimated average requirement (ear): the average daily amount of a nutrient that will maintain a specific biochemical or physiological function in half the healthy people of a given age and gender group. -estimated energy requirement (eer): the average dietary energy intake that maintains energy balance and good health in a person of a given age, gender, weight, height, and level of physical activity. -estrogens: hormones responsible for the menstrual cycle and other female characteristics. -ethanol: a particular type of alcohol found in beer, wine, and distilled liquor; also called ethyl alcohol. -exchange lists: diet-planning tools that organize foods by their proportions of carbohydrate, fat, and protein. -foods on any single list can be used interchangeably. -exercise: planned, structured, and repetitive body movements that promote or maintain physical fitness. -experimental group: a group of individuals similar in all possible respects to the control group except for the treatment. -the experimental group receives the real treatment. -extra lean: less than 5 g of fat, 2 g of saturated fat and trans fat combined, and 95 mg of cholesterol per serving and per 100 g of meat, poultry, and seafood. -extracellular fluid: fluid outside the cells. -extracellular fluid includes two main components the interstitial fluid and plasma. -extracellular fluid accounts for approximately one-third of the body s water. -f fad diets: popular eating plans that promise quick weight loss. -most fad diets severely limit certain foods or overemphasize others (for example, never eat potatoes or pasta or eat cabbage soup daily). -faith healing: healing by invoking divine intervention without the use of medical, surgical, or other traditional therapy. -false negative: a test result indicating that a condition is not present (negative) when in fact it is present (therefore false). -false positive: a test result indicating that a condition is present (positive) when in fact it is not (therefore false). -famine: widespread and extreme scarcity of food in an area that causes starvation and death in a large portion of the population. -fao (food and agriculture organization): an international agency (part of the united nations) that has adopted standards to regulate pesticide use among other responsibilities. -fat replacers: ingredients that replace some or all of the functions of fat and may or may not provide energy. -added fat or oil); synonyms include zero-fat, no- fat, and nonfat. -fats: lipids that are solid at room temperature (77 f or 25 c). -fatty acid: an organic compound composed of a carbon chain with hydrogens attached and an acid group (cooh) at one end and a methyl group (ch3) at the other end. -fatty acid oxidation: the metabolic breakdown of fatty acids to acetyl coa; also called beta oxidation. -fatty liver: an early stage of liver deterioration seen in several diseases, including kwashiorkor and alcoholic liver disease. -fatty liver is characterized by an accumulation of fat in the liver cells. -fatty streaks: accumulations of cholesterol and other lipids along the walls of the arteries. -fda (food and drug administration): a part of the department of health and human services public health service that is responsible for ensuring the safety and wholesomeness of all dietary supplements and food processed and sold in interstate commerce except meat, poultry, and eggs (which are under the jurisdiction of the usda); inspecting food plants and imported foods; and setting standards for food composition and product labeling. -female athlete triad: a potentially fatal combination of three medical problems disordered eating, amenorrhea, and osteoporosis. -fermentable: the extent to which bacteria in the gi tract can break down fibers to fragments that the body can use. -ferritin (fair-ih-tin): the iron storage protein. -fertility: the capacity of a woman to produce a normal ovum periodically and of a man to produce normal sperm; the ability to reproduce. -fetal alcohol spectrum disorder: a range of physical, behavioral, and cognitive abnormalities caused by prenatal alcohol exposure. -fetal alcohol syndrome (fas): a cluster of physical, behavioral, and cognitive abnormalities associated with prenatal alcohol exposure, including facial malformations, growth retardation, and central nervous disorders. -fetal programming: the influence of substances during fetal growth on the development of diseases in later life. -fetus (feet-us): the developing infant from eight weeks after conception until term. -fibrocystic (fye-bro-sis-tik) breast disease: a harmless condition in which the breasts develop lumps, sometimes associated with caffeine consumption. -in some, it responds to abstinence from caffeine; in others, it can be treated with vitamin e. fibrosis (fye-broh-sis): an intermediate stage of liver deterioration seen in several diseases, including viral hepatitis and alcoholic liver disease. -in fibrosis, the liver cells lose their function and assume the characteristics of connective tissue cells (fibers). -filtered water: water treated by filtration, usually through activated carbon filters that reduce the lead in tap water, or by reverse osmosis units that force pressurized water across a membrane removing lead, arsenic, and some microorganisms from tap water. -fitness: the characteristics that enable the body to perform physical activity; more broadly, the ability to meet routine physical demands with enough reserve energy to rise to a physical challenge; or the body s ability to withstand stress of all kinds. -flavonoids (flay-von-oyds): yellow pigments in foods; phytochemicals that may exert physiological effects on the body. -glossary gl-7 foods: products derived from plants or animals that can be taken into the body to yield energy and nutrients for the maintenance of life and the growth and repair of tissues. -fortified: the addition to a food of nutrients that were either not originally present or present in insignificant amounts. -fortification can be used to correct or prevent a widespread nutrient deficiency or to balance the total nutrient profile of a food. -fossil fuels: coal, oil, and natural gas. -generally recognized as safe (gras): food additives that have long been in use and are believed safe. -genes: sections of chromosomes that contain the instructions needed to make one or more proteins. -genetic engineering: the use of biotechnology to modify the genetic material of living cells so that they will produce new substances or perform new functions. -foods produced via this technology are called genetically modified (gm) or genetically engineered (ge) foods. -fraudulent: the promotion, for financial gain, of genetics: the study of genes and inheritance. -flaxseeds: the small brown seeds of the flax plant; valued as a source of linseed oil, fiber, and omega-3 fatty acids. -flexibility: the capacity of the joints to move through a full range of motion; the ability to bend and recover without injury. -fluid balance: maintenance of the proper types and amounts of fluid in each compartment of the body fluids (see also chapter 12). -fluorapatite (floor-app-uh-tite): the stabilized form of bone and tooth crystal, in which fluoride has replaced the hydroxyl groups of hydroxyapatite. -fluorosis (floor-oh-sis): discoloration and pitting of tooth enamel caused by excess fluoride during tooth development. -folate (fole-ate): a b vitamin; also known as folic acid, folacin, or pteroylglutamic (tare-o-eel-glue- tam-ick) acid (pga). -the coenzyme forms are dhf (dihydrofolate) and thf (tetrahydrofolate). -follicle-stimulating hormone (fsh): a hormone that stimulates maturation of the ovarian follicles in females and the production of sperm in males. -(the ovarian follicles are part of the female reproductive system where the eggs are produced.) -the release of fsh is mediated by follicle-stimulating hormone releasing hormone (fsh rh). -food allergy: an adverse reaction to food that involves an immune response; also called food- hypersensitivity reaction. -food aversions: strong desires to avoid particular foods. -food bank: a facility that collects and distributes food donations to authorized organizations feeding the hungry. -food chain: the sequence in which living things depend on other living things for food. -food cravings: strong desires to eat particular foods. -food frequency questionnaire: a checklist of foods on which a person can record the frequency with which he or she eats each food. -food group plans: diet-planning tools that sort foods into groups based on nutrient content and then specify that people should eat certain amounts of foods from each group. -food insecurity: limited or uncertain access to foods of sufficient quality or quantity to sustain a healthy and active life. -food insufficiency: an inadequate amount of food due to a lack of resources. -devices, treatments, services, plans, or products (including diets and supplements) that alter or claim to alter a human condition without proof of safety or effectiveness. -free: nutritionally trivial and unlikely to have a physiological consequence; synonyms include without, no, and zero. -a food that does not contain a nutrient naturally may make such a claim, but only as it applies to all similar foods (for example, applesauce, a fat-free food ). -free radicals: unstable and highly reactive atoms or molecules that have one or more unpaired electrons in the outer orbital. -frequency: the number of occurrences per unit of time (for example, the number of activity sessions per week). -fructose (fruk-tose or frook-tose): a monosaccharide; sometimes known as fruit sugar or levulose. -fructose is found abundantly in fruits, honey, and saps. -fuel: compounds that cells can use for energy. -the major fuels include glucose, fatty acids, and amino acids; other fuels include ketone bodies, lactate, glycerol, and alcohol. -functional foods: foods that contain physiologically active compounds that provide health benefits beyond their nutrient contributions; sometimes called designer foods or nutraceuticals. -g g: grams; a unit of weight equivalent to about 0.03 ounces. -galactose (ga-lak-tose): a monosaccharide; part of the disaccharide lactose. -gallbladder: the organ that stores and concentrates bile. -when it receives the signal that fat is present in the duodenum, the gallbladder contracts and squirts bile through the bile duct into the duodenum. -food intolerances: adverse reactions to foods that do gamma-oryzanol: a plant sterol that supposedly not involve the immune system. -food pantries: programs that provide groceries to be prepared and eaten at home. -food poverty: hunger resulting from inadequate access to available food for various reasons, including inadequate resources, political obstacles, social disruptions, poor weather conditions, and lack of transportation. -food record: an extensive, accurate log of all foods eaten over a period of several days or weeks. -a food record that includes associated information such as when, where, and with whom each food is eaten is sometimes called a food diary. -food recovery: collecting wholesome food for distribution to low-income people who are hungry. -food security: access to enough food to sustain a healthy and active life. -food substitutes: foods that are designed to replace other foods. -foodborne illness: illness transmitted to human beings through food and water, caused by either an infectious agent (foodborne infection) or a poisonous substance (food intoxication); commonly known as food poisoning. -provides the same physical responses as anabolic steroids without the adverse side effects; also known as ferulic acid, ferulate, or frac. -gastric glands: exocrine glands in the stomach wall that secrete gastric juice into the stomach. -gastric juice: the digestive secretion of the gastric glands of the stomach. -gastrin: a hormone secreted by cells in the stomach wall. -target organ: the glands of the stomach. -response: secretion of gastric acid. -gastroesophageal reflux: the backflow of stomach acid into the esophagus, causing damage to the cells of the esophagus and the sensation of heartburn. -gastrointestinal (gi) tract: the digestive tract. -the principal organs are the stomach and intestines. -gatekeepers: with respect to nutrition, key people who control other people s access to foods and thereby exert profound impacts on their nutrition. -gene expression: the process by which a cell converts the genetic code into rna and protein. -gene pool: all the genetic information of a population at a given time. -genome (gee-nome): the full complement of genetic material (dna) in the chromosomes of a cell. -in human beings, the genome consists of 46 chromosomes. -genomics: the study of all the genes in an organism and their interactions with environmental factors. -gestation (jes-tay-shun): the period from conception to birth. -for human beings, the average length of a healthy gestation is 40 weeks. -pregnancy is often divided into three-month periods, called trimesters. -gestational diabetes: abnormal glucose tolerance during pregnancy. -ghrelin (grell-in): a protein produced by the stomach cells that enhances appetite and decreases energy expenditure. -ginseng: a plant whose extract supposedly boosts energy. -side effects of chronic use include nervousness, confusion, and depression. -glands: cells or groups of cells that secrete materials for special uses in the body. -glands may be exocrine (eks-oh-crin) glands, secreting their materials out (into the digestive tract or onto the surface of the skin), or endocrine (en-doe-crin) glands, secreting their materials in (into the blood). -glucagon (gloo-ka-gon): a hormone that is secreted by special cells in the pancreas in response to low blood glucose concentration and elicits release of glucose from liver glycogen stores. -glucocorticoids: hormones from the adrenal cortex that affect the body s management of glucose. -gluconeogenesis (gloo-ko-nee-oh-jen-ih-sis): the making of glucose from a noncarbohydrate source. -glucose (gloo-kose): a monosaccharide; sometimes known as blood sugar or dextrose. -glucose polymers: compounds that supply glucose, not as single molecules, but linked in chains somewhat like starch. -the objective is to attract less water from the body into the digestive tract (osmotic attraction depends on the number, not the size, of particles). -glycemic index: a method of classifying foods according to their potential for raising blood glucose. -glycemic (gly-seem-ic) response: the extent to which a food raises the blood glucose concentration and elicits an insulin response. -glycerol (gliss-er-ol): an alcohol composed of a three-carbon chain, which can serve as the backbone for a triglyceride. -glycogen (gly-ko-jen): an animal polysaccharide composed of glucose; manufactured and stored in the liver and muscles as a storage form of glucose. -glycogen is not a significant food source of carbohydrate and is not counted as one of the complex carbohydrates in foods. -glycolysis (gly-coll-ih-sis): the metabolic breakdown of glucose to pyruvate. -glycolysis does not require oxygen (anaerobic). -goblet cells: cells of the gi tract (and lungs) that secrete mucus. -goiter (goy-ter): an enlargement of the thyroid gland due to an iodine deficiency, malfunction of the gland, or overconsumption of a goitrogen. -goiter caused by iodine deficiency is simple goiter. -gl-8 glossary goitrogen (goy-troh-jen): a substance that enlarges the thyroid gland and causes toxic goiter. -goitrogens occur naturally in such foods as cabbage, kale, brussels sprouts, cauliflower, broccoli, and kohlrabi. -golgi (goal-gee) apparatus: a set of membranes within the cell where secretory materials are packaged for export. -good source of: the product provides between 10 and 19% of the daily value for a given nutrient per serving. -gout (gowt): a common form of arthritis characterized by deposits of uric acid crystals in the joints. -granulated sugar: crystalline sucrose; 99.9% pure. -growth hormone (gh): a hormone secreted by the pituitary that regulates the cell division and protein synthesis needed for normal growth. -the release of gh is mediated by gh-releasing hormone (ghrh). -h hard water: water with a high calcium and magnesium content. -hazard: a source of danger; used to refer to circumstances in which harm is possible under normal conditions of use. -hazard analysis critical control points (haccp): a systematic plan to identify and correct potential microbial hazards in the manufacturing, distribution, and commercial use of food products; commonly referred to as hass-ip. -hdl (high-density lipoprotein): the type of lipoprotein that transports cholesterol back to the liver from the cells; composed primarily of protein. -health claims: statements that characterize the relationship between a nutrient or other substance in a food and a disease or health-related condition. -health history: an account of a client s current and past health status and disease risks. -healthy: a food that is low in fat, saturated fat, cholesterol, and sodium and that contains at least 10% of the daily values for vitamin a, vitamin c, iron, calcium, protein, or fiber. -healthy people: a national public health initiative under the jurisdiction of the u.s. department of health and human services (dhhs) that identifies the most significant preventable threats to health and focuses efforts toward eliminating them. -heart attack: sudden tissue death caused by blockages of vessels that feed the heart muscle; also called myocardial (my-oh-kar-dee-al) infarction (in-fark-shun) or cardiac arrest. -heartburn: a burning sensation in the chest area caused by backflow of stomach acid into the esophagus. -heat stroke: a dangerous accumulation of body heat with accompanying loss of body fluid. -heavy metals: mineral ions such as mercury and lead, so called because they are of relatively high atomic weight. -many heavy metals are poisonous. -heimlich (hime-lick) maneuver (abdominal thrust maneuver): a technique for dislodging an object from the trachea of a choking person. -hematocrit (hee-mat-oh-krit): measurement of the volume of the red blood cells packed by centrifuge in a given volume of blood. -heme (heem): the iron-holding part of the hemoglobin and myoglobin proteins. -about 40% of the iron in meat, fish, and poultry is bound into heme; the other 60% is nonheme iron. -hemochromatosis (he-moh-kro-ma-toe-sis): a genetically determined failure to prevent absorption of unneeded dietary iron that is characterized by iron overload and tissue damage. -hemoglobin (he-moh-glo-bin): the globular protein of the red blood cells that carries oxygen from the lungs to the cells throughout the body. -hemolytic (he-moh-lit-ick) anemia: the condition of having too few red blood cells as a result of erythrocyte hemolysis. -hemophilia (he-moh-feel-ee-ah): a hereditary disease in which the blood is unable to clot because it lacks the ability to synthesize certain clotting factors. -hemorrhagic (hem-oh-raj-ik) disease: a disease characterized by excessive bleeding. -hemorrhoids (hem-oh-royds): painful swelling of the veins surrounding the rectum. -hemosiderin (heem-oh-sid-er-in): an iron-storage protein primarily made in times of iron overload. -hemosiderosis (he-moh-sid-er-oh-sis): a condition characterized by the deposition of hemosiderin in the liver and other tissues. -hepatic portal vein: the vein that collects blood from the gi tract and conducts it to capillaries in the liver. -hepatic vein: the vein that collects blood from the liver capillaries and returns it to the heart. -hepcidin: a hormone produced by the liver that regulates iron balance. -herbal (erb-al) medicine: the use of plants to treat disease or improve health; also known as botanical medicine or phytotherapy. -hgh (human growth hormone): a hormone produced by the brain s pituitary gland that regulates normal growth and development; also called somatotropin. -some athletes misuse this hormone to increase their height and strength. -hiccups (hick-ups): repeated cough-like sounds and jerks that are produced when an involuntary spasm of the diaphragm muscle sucks air down the windpipe; also spelled hiccoughs. -high: 20% or more of the daily value for a given nutrient per serving; synonyms include rich in or excellent source. -high fiber: 5 g or more fiber per serving. -a high-fiber claim made on a food that contains more than 3 g fat per serving and per 100 g of food must also declare total fat. -high potency: 100% or more of the daily value for the nutrient in a single supplement and for at least two- thirds of the nutrients in a multinutrient supplement. -high-fructose corn syrup (hfcs): a syrup made from cornstarch that has been treated with an enzyme that converts some of the glucose to the sweeter fructose; made especially for use in processed foods and beverages, where it is the predominant sweetener. -high-quality proteins: dietary proteins containing all the essential amino acids in relatively the same amounts that human beings require. -they may also contain nonessential amino acids. -high-risk pregnancy: a pregnancy characterized by indicators that make it likely the birth will be surrounded by problems such as premature delivery, difficult birth, retarded growth, birth defects, and early infant death. -histamine (hiss-tah-mean or hiss-tah-men): a substance produced by cells of the immune system as part of a local immune reaction to an antigen; participates in causing inflammation. -hiv (human immunodeficiency virus): the virus that causes aids. -the infection progresses to become an immune system disorder that leaves its victims defenseless against numerous infections. -hmb (beta-hydroxy-beta-methylbutyrate): a metabolite of the branched-chain amino acid leucine. -claims that hmb increases muscle mass and strength are based on the results of two studies from the lab that developed hmb as a supplement. -homeopathy (hoh-me-op-ah-thee): a practice based on the theory that like cures like, that is, that substances that cause symptoms in healthy people can cure those symptoms when given in very dilute amounts. -homeostasis (home-ee-oh-stay-sis): the maintenance of constant internal conditions (such as blood chemistry, temperature, and blood pressure) by the body s control systems. -a homeostatic system is constantly reacting to external forces to maintain limits set by the body s needs. -honey: sugar (mostly sucrose) formed from nectar gathered by bees. -an enzyme splits the sucrose into glucose and fructose. -composition and flavor vary, but honey always contains a mixture of sucrose, fructose, and glucose. -hormones: chemical messengers. -hormones are secreted by a variety of glands in response to altered conditions in the body. -each hormone travels to one or more specific target tissues or organs, where it elicits a specific response to maintain homeostasis. -hormone-sensitive lipase: an enzyme inside adipose cells that responds to the body s need for fuel by hydrolyzing triglycerides so that their parts (glycerol and fatty acids) escape into the general circulation and thus become available to other cells for fuel. -the signals to which this enzyme responds include epinephrine and glucagon, which oppose insulin. -hourly sweat rate: the amount of weight lost plus fluid consumed during exercise per hour. -human genome (gee-nome): the full complement of genetic material in the chromosomes of a person s cells. -hunger: the painful sensation caused by a lack of food that initiates food-seeking behavior; a consequence of food insecurity that, because of prolonged, involuntary lack of food, results in discomfort, illness, weakness, or pain that goes beyond the usual uneasy sensation. -hydrochloric acid: an acid composed of hydrogen and chloride atoms (hcl) that is normally produced by the gastric glands. -hydrogenation (high-dro-jen-ay-shun or high-droj- eh-nay-shun): a chemical process by which hydrogens are added to monounsaturated or polyunsaturated fatty acids to reduce the number of double bonds, making the fats more saturated (solid) and more resistant to oxidation (protecting against rancidity). -hydrogenation produces trans- fatty acids. -hydrolysis (high-drol-ih-sis): a chemical reaction in which a major reactant is split into two products, with the addition of a hydrogen atom (h) to one and a hydroxyl group (oh) to the other (from water, h2o). -(the noun is hydrolysis; the verb is hydrolyze.) -hydrophilic (high-dro-fil-ick): a term referring to water-loving, or water-soluble, substances. -hydrophobic (high-dro-foe-bick): a term referring to water-fearing, or non-water-soluble, substances; also known as lipophilic (fat loving). -hydrotherapy: the use of water (in whirlpools, as douches, or packed as ice, for example) to promote relaxation and healing. -hydroxyapatite (high-drox-ee-app-ah-tite): crystals made of calcium and phosphorus. -hyperactivity: inattentive and impulsive behavior that is more frequent and severe than is typical of others a similar age; professionally called attention- deficit/hyperactivity disorder (adhd). -hyperglycemia: elevated blood glucose concentrations. -hypertension: higher-than-normal blood pressure. -hypertension that develops without an identifiable cause is known as essential or primary hypertension; hypertension that is caused by a specific disorder such as kidney disease is known as secondary hypertension. -hyperthermia: an above-normal body temperature. -hypertrophy (high-per-tro-fee): growing larger; with regard to muscles, an increase in size (and strength) in response to use. -hypnotherapy: a technique that uses hypnosis and the power of suggestion to improve health behaviors, relieve pain, and heal. -hypoallergenic formulas: clinically tested infant formulas that support infant growth and develop- ment but do not provoke reactions in 90% of infants or children with confirmed cow s milk allergy. -hypoglycemia (high-po-gly-see-me-ah): an abnormally low blood glucose concentration. -hyponatremia (high-poe-na-tree-mee-ah): a decreased concentration of sodium in the blood. -hypothalamus (high-po-thal-ah-mus): a brain center that controls activities such as maintenance of water balance, regulation of body temperature, and control of appetite. -hypothermia: a below-normal body temperature. -hypothesis (hi-poth-eh-sis): an unproven statement that tentatively explains the relationships between two or more variables. -i ileocecal (ill-ee-oh-seek-ul) valve: the sphincter separating the small and large intestines. -ileum (ill-ee-um): the last segment of the small intestine. -imagery: a technique that guides clients to achieve a desired physical, emotional, or spiritual state by visualizing themselves in that state. -imitation foods: foods that substitute for and resemble another food, but are nutritionally inferior to it with respect to vitamin, mineral, or protein content. -if the substitute is not inferior to the food it resembles and if its name provides an accurate description of the product, it need not be labeled imitation. -immune system: the body s natural defense against foreign materials that have penetrated the skin or mucous membranes. -immunity: the body s ability to defend itself against diseases (see also chapter 18). -immunoglobulins (im-you-noh-glob-you-linz): proteins capable of acting as antibodies. -implantation: the stage of development in which the zygote embeds itself in the wall of the uterus and begins to develop; occurs during the first two weeks after conception. -indigestion: incomplete or uncomfortable digestion, usually accompanied by pain, nausea, vomiting, heartburn, intestinal gas, or belching. -indirect or incidental additives: substances that can get into food as a result of contact during growing, processing, packaging, storing, cooking, or some other stage before the foods are consumed; sometimes called accidental additives. -infectious diseases: diseases caused by bacteria, viruses, parasites, or other microorganisms that can be transmitted from one person to another through air, water, or food; by contact; or through vector organisms such as mosquitoes. -inflammation: an immunological response to cellular injury characterized by an increase in white blood cells. -initiators: factors that cause mutations that give rise to cancer, such as radiation and carcinogens. -inorganic: not containing carbon or pertaining to living things. -glossary gl-9 inositol (in-oss-ih-tall): a nonessential nutrient that can be made in the body from glucose. -inositol is a part of cell membrane structures. -insoluble fibers: indigestible food components that do not dissolve in water. -examples include the tough, fibrous structures found in the strings of celery and the skins of corn kernels. -insulin (in-suh-lin): a hormone secreted by special cells in the pancreas in response to (among other things) increased blood glucose concentration. -the primary role of insulin is to control the transport of glucose from the bloodstream into the muscle and fat cells. -insulin resistance: the condition in which a normal amount of insulin produces a subnormal effect in muscle, adipose, and liver cells, resulting in an elevated fasting glucose; a metabolic consequence of obesity that precedes type 2 diabetes. -integrative medicine: an approach that incorporates alternative therapies into the practice of conventional medicine (similar to complementary medicine, but a closer relationship is implied). -intensity: the degree of exertion while exercising (for example, the amount of weight lifted or the speed of running). -iu: international units; an old measure of vitamin activity determined by biological methods (as opposed to new measures that are determined by direct chemical analyses). -many fortified foods and supplements use iu on their labels. -j jejunum (je-joon-um): the first two-fifths of the small intestine beyond the duodenum. -k kcal: kcalories; a unit by which energy is measured. -kcalorie (energy) control: management of food energy intake. -kcalorie-free: fewer than 5 kcal per serving. -kefir (keh-fur): a fermented milk created by adding lactobacillus acidophilus and other bacteria that break down lactose to glucose and galactose, producing a sweet, lactose-free product. -keratin (kare-uh-tin): a water-insoluble protein; the normal protein of hair and nails. -keratinization: accumulation of keratin in a tissue; a sign of vitamin a deficiency. -intentional food additives: additives intentionally added to foods, such as nutrients, colors, and preservatives. -keratomalacia (kare-ah-toe-ma-lay-shuh): softening of the cornea that leads to irreversible blindness; seen in severe vitamin a deficiency. -intermittent claudication (klaw-dih-kay-shun): keto (key-toe) acid: an organic acid that contains a severe calf pain caused by inadequate blood supply. -it occurs when walking and subsides during rest. -internet (the net): a worldwide network of millions of computers linked together to share information. -interstitial (in-ter-stish-al) fluid: fluid between the cells (intercellular), usually high in sodium and chloride. -interstitial fluid is a large component of extracellular fluid. -intra-abdominal fat: fat stored within the abdominal cavity in association with the internal abdominal organs, as opposed to the fat stored directly under the skin (subcutaneous fat). -carbonyl group (c=o). -ketone (kee-tone) bodies: the product of the incomplete breakdown of fat when glucose is not available in the cells. -ketosis (kee-toe-sis): an undesirably high concentration of ketone bodies in the blood and urine. -kwashiorkor (kwash-ee-or-core, kwash-ee-or-core): a form of pem that results either from inadequate protein intake or, more commonly, from infections. -lactadherin (lack-tad-hair-in): a protein in breast l intracellular fluid: fluid within the cells, usually high milk that attacks diarrhea-causing viruses. -in potassium and phosphate. -intracellular fluid accounts for approximately two-thirds of the body s water. -intrinsic factor: a glycoprotein (a protein with short polysaccharide chains attached) secreted by the stomach cells that binds with vitamin b12 in the small intestine to aid in the absorption of vitamin b12. -invert sugar: a mixture of glucose and fructose formed by the hydrolysis of sucrose in a chemical process; sold only in liquid form and sweeter than sucrose. -invert sugar is used as a food additive to help preserve freshness and prevent shrinkage. -ions (eye-uns): atoms or molecules that have gained or lost electrons and therefore have electrical charges. -examples include the positively charged sodium ion (na+) and the negatively charged chloride ion (cl-). -iridology: the study of changes in the iris of the eye and their relationships to disease. -iron deficiency: the state of having depleted iron stores. -iron overload: toxicity from excess iron. -iron-deficiency anemia: severe depletion of iron stores that results in low hemoglobin and small, pale red blood cells. -anemias that impair hemoglobin synthesis are microcytic (small cell). -irradiation: sterilizing a food by exposure to energy waves, similar to ultraviolet light and microwaves. -irritable bowel syndrome: an intestinal disorder of unknown cause. -symptoms include abdominal discomfort and cramping, diarrhea, constipation, or alternating diarrhea and constipation. -lactase: an enzyme that hydrolyzes lactose. -lactase deficiency: a lack of the enzyme required to digest the disaccharide lactose into its component monosaccharides (glucose and galactose). -lactate: a 3-carbon compound produced from pyruvate during anaerobic metabolism. -lactation: production and secretion of breast milk for the purpose of nourishing an infant. -lactoferrin (lack-toh-ferr-in): a protein in breast milk that binds iron and keeps it from supporting the growth of the infant s intestinal bacteria. -lacto-ovo-vegetarians: people who include milk, milk products, and eggs, but exclude meat, poultry, fish, and seafood from their diets. -lactose (lak-tose): a disaccharide composed of glucose and galactose; commonly known as milk sugar. -lactose intolerance: a condition that results from inability to digest the milk sugar lactose; characterized by bloating, gas, abdominal discomfort, and diarrhea. -lactovegetarians: people who include milk and milk products, but exclude meat, poultry, fish, seafood, and eggs from their diets. -large intestine or colon (coal-un): the lower portion of intestine that completes the digestive process. -its segments are the ascending colon, the transverse colon, the descending colon, and the sigmoid colon. -larynx: the upper part of the air passageway that contains the vocal cords; also called the voice box. -laxatives: substances that loosen the bowels and thereby prevent or treat constipation. -gl-10 glossary ldl (low-density lipoprotein): the type of lipoprotein derived from very-low-density lipoproteins (vldl) as vldl triglycerides are removed and broken down; composed primarily of cholesterol. -lean: less than 10 g of fat, 4.5 g of saturated fat and trans fat combined, and 95 mg of cholesterol per serving and per 100 g of meat, poultry, and seafood. -pasteurization and cooking but can survive at refrigerated temperatures; certain ready-to-eat foods, such as hot dogs and deli meats, may become contaminated after cooking or processing, but before packaging. -liver: the organ that manufactures bile. -(the liver s many other functions are described in chapter 7.) -lean body mass: the body minus its fat. -longevity: long duration of life. -lecithin (less-uh-thin): one of the phospholipids. -low: an amount that would allow frequent both nature and the food industry use lecithin as an emulsifier to combine water-soluble and fat-soluble ingredients that do not ordinarily mix, such as water and oil. -legumes (lay-gyooms, leg-yooms): plants of the bean and pea family, with seeds that are rich in protein compared with other plant-derived foods. -leptin: a protein produced by fat cells under direction of the ob gene that decreases appetite and increases energy expenditure; sometimes called the ob protein. -less: at least 25% less of a given nutrient or kcalories than the comparison food (see individual nutrients); synonyms include fewer and reduced. -less cholesterol: 25% or less cholesterol than the comparison food (reflecting a reduction of at least 20 mg per serving), and 2 g or less saturated fat and trans fat combined per serving. -consumption of a food without exceeding the daily value for the nutrient. -a food that is naturally low in a nutrient may make such a claim, but only as it applies to all similar foods (for example, fresh cauliflower, a low-sodium food ); synonyms include little, few, and low source of. -low birthweight (lbw): a birthweight of 51/2 lb (2500 g) or less; indicates probable poor health in the newborn and poor nutrition status in the mother during pregnancy, before pregnancy, or both. -normal birthweight for a full-term baby is 61/2 to 83/4 lb (about 3000 to 4000 g). -low cholesterol: 20 mg or less cholesterol per serving and 2 g or less saturated fat and trans fat combined per serving. -low fat: 3 g or less fat per serving. -low kcalorie: 40 kcal or less per serving. -low saturated fat: 1 g or less saturated fat and less less fat: 25% or less fat than the comparison food. -than 0.5 g of trans fat per serving. -less saturated fat: 25% or less saturated fat and trans low sodium: 140 mg or less per serving. -fat combined than the comparison food. -let-down reflex: the reflex that forces milk to the front of the breast when the infant begins to nurse. -low-risk pregnancy: a pregnancy characterized by indicators that make a normal outcome likely. -lumen (loo-men): the space within a vessel, such as levulose: an older name for fructose. -the intestine. -magnesium: a cation within the body s cells, active in many enzyme systems. -major minerals: essential mineral nutrients found in the human body in amounts larger than 5 g; sometimes called macrominerals. -malignant (ma-lig-nant): describes a cancerous cell or tumor, which can injure healthy tissue and spread cancer to other regions of the body. -malnutrition: any condition caused by excess or deficient food energy or nutrient intake or by an imbalance of nutrients. -maltose (mawl-tose): a disaccharide composed of two glucose units; sometimes known as malt sugar. -maltase: an enzyme that hydrolyzes maltose. -mammary glands: glands of the female breast that secrete milk. -maple sugar: a sugar (mostly sucrose) purified from the concentrated sap of the sugar maple tree. -marasmus (ma-raz-mus): a form of pem that results from a severe deprivation, or impaired absorption, of energy, protein, vitamins, and minerals. -margin of safety: when speaking of food additives, a zone between the concentration normally used and that at which a hazard exists. -for common table salt, for example, the margin of safety is 1/5 (five times the amount normally used would be hazardous). -massage therapy: a healing method in which the therapist manually kneads muscles to reduce tension, increase blood circulation, improve joint mobility, and promote healing of injuries. -matrix (may-tricks): the basic substance that gives form to a developing structure; in the body, the formative cells from which teeth and bones grow. -license to practice: permission under state or federal law, granted on meeting specified criteria, to use a certain title (such as dietitian) and offer certain services. -licensed dietitians may use the initials ld after their names. -life expectancy: the average number of years lived by people in a given society. -life span: the maximum number of years of life attainable by a member of a species. -light or lite: one-third fewer kcalories than the comparison food; 50% or less of the fat or sodium than the comparison food; any use of the term other than as defined must specify what it is referring to (for example, light in color or light in texture ). -lignans: phytochemicals present in flaxseed, but not in flax oil, that are converted to phytosterols by intestinal bacteria and are under study as possible anticancer agents. -limiting amino acid: the essential amino acid found in the shortest supply relative to the amounts needed for protein synthesis in the body. -linoleic (lin-oh-lay-ick) acid: an essential fatty acid with 18 carbons and two double bonds. -linolenic (lin-oh-len-ick) acid: an essential fatty acid with 18 carbons and three double bonds. -lipids: a family of compounds that includes triglycerides, phospholipids, and sterols. -lipids are characterized by their insolubility in water. -(lipids also include the fat-soluble vitamins, described in chapter 11.) -lipoprotein lipase (lpl): an enzyme that hydrolyzes triglycerides passing by in the bloodstream and directs their parts into the cells, where they can be metabolized for energy or reassembled for storage. -lipoproteins (lip-oh-pro-teenz): clusters of lipids associated with proteins that serve as transport vehicles for lipids in the lymph and blood. -listeriosis: an infection caused by eating food contaminated with the bacterium listeria monocytogenes, which can be killed by lutein (loo-teen): a plant pigment of yellow hue; a matter: anything that takes up space and has mass. -phytochemical believed to play roles in eye functioning and health. -luteinizing (loo-tee-in-eye-zing) hormone (lh): a hormone that stimulates ovulation and the development of the corpus luteum (the small tissue that develops from a ruptured ovarian follicle and secretes hormones); so called because the follicle turns yellow as it matures. -in men, lh stimulates testosterone secretion. -the release of lh is mediated by luteinizing hormone releasing hormone (lh rh). -lycopene (lye-koh-peen): a pigment responsible for the red color of tomatoes and other red-hued vegetables; a phytochemical that may act as an antioxidant in the body. -lymph (limf): a clear yellowish fluid that is similar to blood except that it contains no red blood cells or platelets. -lymph from the gi tract transports fat and fat-soluble vitamins to the bloodstream via lymphatic vessels. -lymphatic (lim-fat-ic) system: a loosely organized system of vessels and ducts that convey fluids toward the heart. -the gi part of the lymphatic system carries the products of fat digestion into the bloodstream. -lymphocytes (lim-foh-sites): white blood cells that participate in acquired immunity; b-cells and t-cells. -lysosomes (lye-so-zomes): cellular organelles; membrane-enclosed sacs of degradative enzymes. -m macrobiotic diets: extremely restrictive diets limited to a few grains and vegetables; based on metaphysical beliefs and not on nutrition. -a macrobiotic diet might consist of brown rice, miso soup, and sea vegetables, for example. -macular (mack-you-lar) degeneration: deterioration of the macular area of the eye that can lead to loss of central vision and eventual blindness. -the macula is a small, oval, yellowish region in the center of the retina that provides the sharp, straight-ahead vision so critical to reading and driving. -meals on wheels: a nutrition program that delivers food for the elderly to their homes. -meat replacements: products formulated to look and taste like meat, fish, or poultry; usually made of textured vegetable protein. -meditation: a self-directed technique of relaxing the body and calming the mind. -meos or microsomal (my-krow-so-mal) ethanol- oxidizing system: a system of enzymes in the liver that oxidize not only alcohol but also several classes of drugs. -metabolic syndrome: a combination of risk factors insulin resistance, hypertension, abnormal blood lipids, and abdominal obesity that greatly increase a person s risk of developing coronary heart disease; also called syndrome x, insulin resistance syndrome, or dysmetabolic syndrome. -metabolism: the sum total of all the chemical reactions that go on in living cells. -energy metabolism includes all the reactions by which the body obtains and expends the energy from food. -metalloenzymes (meh-tal-oh-en-zimes): enzymes that contain one or more minerals as part of their structures. -metallothionein (meh-tal-oh-thigh-oh-neen): a sulfur-rich protein that avidly binds with and transports metals such as zinc. -metastasize (me-tas-tah-size): the spread of cancer from one part of the body to another. -mfp factor: a peptide released during the digestion of meat, fish, and poultry that enhances nonheme iron absorption. -micelles (my-cells): tiny spherical complexes of emulsified fat that arise during digestion; most contain bile salts and the products of lipid digestion, including fatty acids, monoglycerides, and cholesterol. -g: micrograms; one-millionth of a gram. -g dfe: micrograms dietary folate equivalents; a generally recognized as safe ingredient. -neuropeptide y: a chemical produced in the brain glossary gl-11 measure of folate activity. -g rae: micrograms retinol activity equivalents; a measure of vitamin a activity. -microarray technology: research tools that analyze the expression of thousands of genes simultaneously and search for particular gene changes associated with a disease. -dna microarrays are also called dna chips. -microvilli (my-cro-vill-ee, my-cro-vill-eye): tiny, hairlike projections on each cell of every villus that can trap nutrient particles and transport them into the cells; singular microvillus. -milk anemia: iron-deficiency anemia that develops when an excessive milk intake displaces iron-rich foods from the diet. -milliequivalents (meq): the concentration of electrolytes in a volume of solution. -milliequivalents are a useful measure when considering ions because the number of charges reveals characteristics about the solution that are not evident when the concentration is expressed in terms of weight. -mg: milligrams; one-thousandth of a gram. -mg ne: milligrams niacin equivalents; a measure of niacin activity. -mmol: millimoles; one thousandth of a mole, the molecular weight of a substance. -to convert mmol to mg, multiply by the atomic weight of the substance. -mineral oil: a purified liquid derived from petroleum monounsaturated fatty acid (mufa): a fatty acid that lacks two hydrogen atoms and has one double bond between carbons for example, oleic acid. -a monounsaturated fat is composed of triglycerides in which most of the fatty acids are monounsaturated. -more: at least 10% more of the daily value for a given nutrient than the comparison food; synonyms include added and extra. -mouth: the oral cavity containing the tongue and teeth. -msg symptom complex: an acute, temporary intolerance reaction that may occur after the ingestion of the additive msg (monosodium glutamate). -symptoms include burning sensations, chest and facial flushing and pain, and throbbing headaches. -mucous (myoo-kus) membranes: the membranes, composed of mucus-secreting cells, that line the surfaces of body tissues. -mucus (myoo-kus): a slippery substance secreted by cells of the gi lining (and other body linings) that protects the cells from exposure to digestive juices (and other destructive agents). -muscle dysmorphia (dis-more-fee-ah): a psychiatric disorder characterized by a preoccupation with building body mass. -muscle endurance: the ability of a muscle to contract repeatedly without becoming exhausted. -and used to treat constipation. -muscle strength: the ability of muscles to work mineral water: water from a spring or well that typically contains 250 to 500 parts per million (ppm) of minerals. -mineralization: the process in which calcium, phosphorus, and other minerals crystallize on the collagen matrix of a growing bone, hardening the bone. -against resistance. -muscular dystrophy (dis-tro-fee): a hereditary disease in which the muscles gradually weaken. -its most debilitating effects arise in the lungs. -be inherited. -myoglobin: the oxygen-holding protein of the minerals: inorganic elements. -some minerals are muscle cells. -essential nutrients required in small amounts by the body for health. -misinformation: false or misleading information. -mitochondria (my-toh-kon-dree-uh); singular mitochondrion: the cellular organelles responsible for producing atp aerobically; made of membranes (lipid and protein) with enzymes mounted on them. -moderate exercise: activity equivalent to the rate of exertion reached when walking at a speed of 4 miles per hour (15 minutes to walk one mile). -moderation: in relation to alcohol consumption, not more than two drinks a day for the average-size man and not more than one drink a day for the average-size woman. -moderation (dietary): providing enough but not too much of a substance. -molasses: the thick brown syrup produced during sugar refining. -molasses retains residual sugar and other by- products and a few minerals; blackstrap molasses contains significant amounts of calcium and iron. -molecule: two or more atoms of the same or different elements joined by chemical bonds. -examples are molecules of the element oxygen, composed of two oxygen atoms (o2), and molecules of the compound water, composed of two hydrogen atoms and one oxygen atom (h2o). -molybdenum (mo-lib-duh-num): a trace element. -monoglycerides: molecules of glycerol with one fatty acid attached. -a molecule of glycerol with two fatty acids attached is a diglyceride. -monosaccharides (mon-oh-sack-uh-rides): carbohydrates of the general formula cnh2non that typically form a single ring. -monosodium glutamate (msg): a sodium salt of the amino acid glutamic acid commonly used as a flavor enhancer. -the fda classifies msg as a n nad (nicotinamide adenine dinucleotide): the main coenzyme form of the vitamin niacin. -its reduced form is nadh. -narcotic (nar-kot-ic): a drug that dulls the senses, induces sleep, and becomes addictive with prolonged use. -natural water: water obtained from a spring or well that is certified to be safe and sanitary. -the mineral content may not be changed, but the water may be treated in other ways such as with ozone or by filtration. -naturopathic (nay-chur-oh-path-ick) medicine: a system that taps the natural healing forces within the body by integrating several practices, including traditional medicine, herbal medicine, clinical nutrition, homeopathy, acupuncture, east asian medicine, hydrotherapy, and manipulative therapy. -neotame (nee-oh-tame): an artificial sweetener composed of two amino acids (phenylalanine and aspartic acid); approved for use in the united states. -net protein utilization (npu): a measure of protein quality assessed by measuring the amount of protein nitrogen that is retained from a given amount of protein nitrogen eaten. -neural tube: the embryonic tissue that forms the brain and spinal cord. -neural tube defects: malformations of the brain, spinal cord, or both during embryonic development that often result in lifelong disability or death. -neurofibrillary tangles: snarls of the threadlike strands that extend from the nerve cells, commonly found in the brains of people with alzheimer s dementia. -neurons: nerve cells; the structural and functional units of the nervous system. -neurons initiate and conduct nerve impulse transmissions. -that stimulates appetite, diminishes energy expenditure, and increases fat storage. -neurotransmitters: chemicals that are released at the end of a nerve cell when a nerve impulse arrives there. -they diffuse across the gap to the next cell and alter the membrane of that second cell to either inhibit or excite it. -niacin (nigh-a-sin): a b vitamin. -the coenzyme forms are nad (nicotinamide adenine dinucleotide) and nadp (the phosphate form of nad). -niacin can be eaten preformed or made in the body from its precursor, tryptophan, one of the amino acids. -niacin equivalents (ne): the amount of niacin present in food, including the niacin that can theoretically be made from its precursor, tryptophan, present in the food. -niacin flush: a temporary burning, tingling, and itching sensation that occurs when a person takes a large dose of nicotinic acid; often accompanied by a headache and reddened face, arms, and chest. -night blindness: slow recovery of vision after flashes of bright light at night or an inability to see in dim light; an early symptom of vitamin a deficiency. -nitrites (nye-trites): salts added to food to prevent botulism. -one example is sodium nitrite, which is used to preserve meats. -nitrogen balance: the amount of nitrogen consumed (n in) as compared with the amount of nitrogen excreted (n out) in a given period of time. -nitrosamines (nye-trohs-uh-meens): derivatives of nitrites that may be formed in the stomach when nitrites combine with amines. -nitrosamines are carcinogenic in animals. -nonessential amino acids: amino acids that the body nonnutritive sweeteners: sweeteners that yield no energy (or insignificant energy in the case of aspartame). -nonpoint water pollution: water pollution caused by runoff from all over an area rather than from discrete point sources. -an example is the pollution caused by runoff from agricultural fields. -nucleotide bases: the nitrogen-containing building blocks of dna and rna cytosine (c), thymine (t), uracil (u), guanine (g), and adenine (a). -in dna, the base pairs are a t and c g and in rna, the base pairs are a u and c g. nucleotides: the subunits of dna and rna molecules, composed of a phosphate group, a 5- carbon sugar (deoxyribose for dna and ribose for rna), and a nitrogen-containing base. -nucleus: a major membrane-enclosed body within every cell, which contains the cell s genetic material, dna, embedded in chromosomes. -nursing bottle tooth decay: extensive tooth decay due to prolonged tooth contact with formula, milk, fruit juice, or other carbohydrate-rich liquid offered to an infant in a bottle. -nutrient claims: statements that characterize the quantity of a nutrient in a food. -nutrient density: a measure of the nutrients a food provides relative to the energy it provides. -the more nutrients and the fewer kcalories, the higher the nutrient density. -nutrients: chemical substances obtained from food and used in the body to provide energy, structural materials, and regulating agents to support growth, maintenance, and repair of the body s tissues. -nutrients may also reduce the risks of some diseases. -nutrition: the science of foods and the nutrients and other substances they contain, and of their actions within the body (including ingestion, digestion, absorption, transport, metabolism, and excretion). -a broader definition includes the social, economic, mutations: a permanent change in the dna that can can synthesize (see table 6-1). -gl-12 glossary cultural, and psychological implications of food and eating. -orthomolecular medicine: the use of large doses of pathogen (path-oh-jen): a microorganism capable of vitamins to treat chronic disease. -producing disease. -nutrition assessment: a comprehensive analysis of a osmosis: the movement of water across a membrane pbb (polybrominated biphenyl) and pcb person s nutrition status that uses health, socioeconomic, drug, and diet histories; anthropometric measurements; physical examinations; and laboratory tests. -nutrition screening: the use of preliminary nutrition assessment techniques to identify people who are malnourished or are at risk for malnutrition. -nutritional genomics: the science of how nutrients affect the activities of genes (nutrigenomics) and how genes affect the interactions between diet and disease (nutrigenetics). -nutritionist: a person who specializes in the study of nutrition. -note that this definition does not specify qualifications and may apply not only to registered dietitians but also to self-described experts whose training is questionable. -most states have licensing laws that define the scope of practice for those calling themselves nutritionists. -nutritive sweeteners: sweeteners that yield energy, including both sugars and sugar replacers. -o obese: overweight with adverse health effects; bmi 30 or higher. -oils: lipids that are liquid at room temperature (77 f or 25 c). -olestra: a synthetic fat made from sucrose and fatty acids that provides 0 kcalories per gram; also known as sucrose polyester. -omega: the last letter of the greek alphabet ( ), used by chemists to refer to the position of the first double bond from the methyl (ch3) end of a fatty acid. -omega-3 fatty acid: a polyunsaturated fatty acid in which the first double bond is three carbons away from the methyl (ch3) end of the carbon chain. -omega-6 fatty acid: a polyunsaturated fatty acid in which the first double bond is six carbons from the methyl (ch3) end of the carbon chain. -omnivores: people who have no formal restriction on the eating of any foods. -opsin (op-sin): the protein portion of the visual pigment molecule. -oral rehydration therapy (ort): the administration of a simple solution of sugar, salt, and water, taken by mouth, to treat dehydration caused by diarrhea. -organelles: subcellular structures such as ribosomes, mitochondria, and lysosomes. -organic: in agriculture, crops grown and processed according to usda regulations defining the use of fertilizers, herbicides, insecticides, fungicides, preservatives, and other chemical ingredients. -organic: in chemistry, a substance or molecule containing carbon-carbon bonds or carbon- hydrogen bonds. -this definition excludes coal, diamonds, and a few carbon-containing compounds that contain only a single carbon and no hydrogen, such as carbon dioxide (co2), calcium carbonate (caco3), magnesium carbonate (mgco3), and sodium cyanide (nacn). -organic: on food labels, that at least 95% of the product s ingredients have been grown and processsed according to usda regulations defining the use of fertilizers, herbicides, insecticides, fungicides, preservatives, and other chemical ingredients (see chapter 19). -organic halogens: an organic compound containing one or more atoms of a halogen fluorine, chlorine, iodine, or bromine. -orlistat (or-leh-stat): a drug used in the treatment of obesity that inhibits the absorption of fat in the gi tract, thus limiting kcaloric intake. -toward the side where the solutes are more concentrated. -osmotic pressure: the amount of pressure needed to prevent the movement of water across a membrane. -osteoarthritis: a painful, degenerative disease of the joints that occurs when the cartilage in a joint deteriorates; joint structure is damaged, with loss of function; also called degenerative arthritis. -osteomalacia (os-tee-oh-ma-lay-shuh): a bone disease characterized by softening of the bones. -symptoms include bending of the spine and bowing of the legs. -the disease occurs most often in adult women. -osteoporosis (os-tee-oh-pore-oh-sis): a disease in which the bones become porous and fragile due to a loss of minerals; also called adult bone loss. -overnutrition: excess energy or nutrients. -overt (oh-vert): out in the open and easy to observe. -overweight: body weight above some standard of acceptable weight that is usually defined in relation to height (such as bmi); bmi 25 to 29.9. ovum (oh-vum): the female reproductive cell, capable of developing into a new organism upon fertilization; commonly referred to as an egg. -oxaloacetate (oks-ah-low-as-eh-tate): a carbohydrate intermediate of the tca cycle. -oxidants (oks-ih-dants): compounds (such as oxygen itself) that oxidize other compounds. -compounds that prevent oxidation are called antioxidants, whereas those that promote it are called prooxidants. -oxidation (oks-ee-day-shun): the process of a substance combining with oxygen; oxidation reactions involve the loss of electrons. -oxidative stress: a condition in which the production of oxidants and free radicals exceeds the body s ability to handle them and prevent damage. -oxytocin (ock-see-toh-sin): a hormone that stimulates the mammary glands to eject milk during lactation and the uterus to contract during childbirth. -oyster shell: a product made from the powdered shells of oysters that is sold as a calcium supplement, but it is not well absorbed by the digestive system. -ozone therapy: the use of ozone gas to enhance the body s immune system. -p pancreas: a gland that secretes digestive enzymes and juices into the duodenum. -(the pancreas also secretes hormones into the blood that help to maintain glucose homeostasis.) -pancreatic (pank-ree-at-ic) juice: the exocrine secretion of the pancreas, containing enzymes for the digestion of carbohydrate, fat, and protein as well as bicarbonate, a neutralizing agent. -the juice flows from the pancreas into the small intestine through the pancreatic duct. -(the pancreas also has an endocrine function, the secretion of insulin and other hormones.) -pantothenic (pan-toe-then-ick) acid: a b vitamin. -the principal active form is part of coenzyme a, called coa throughout chapter 7. parathyroid hormone: a hormone from the parathyroid glands that regulates blood calcium by raising it when levels fall too low; also known as parathormone (pair-ah-thor-moan). -pasteurization: heat processing of food that inactivates some, but not all, microorganisms in the food; not a sterilization process. -bacteria that cause spoilage are still present. -(polychlorinated biphenyl): toxic organic compounds used in pesticides, paints, and flame retardants. -pdcaas (protein digestibility corrected amino acid score): a measure of protein quality assessed by comparing the amino acid score of a food protein with the amino acid requirements of preschool-age children and then correcting for the true digestibility of the protein; recommended by the fao/who and used to establish protein quality of foods for daily value percentages on food labels. -peak bone mass: the highest attainable bone density for an individual, developed during the first three decades of life. -peer review: a process in which a panel of scientists rigorously evaluates a research study to assure that the scientific method was followed. -pellagra (pell-ay-gra): the niacin-deficiency disease. -pepsin: a gastric enzyme that hydrolyzes protein. -pepsin is secreted in an inactive form, pepsinogen, which is activated by hydrochloric acid in the stomach. -peptic ulcer: a lesion in the mucous membrane of either the stomach (a gastric ulcer) or the duodenum (a duodenal ulcer). -peptidase: a digestive enzyme that hydrolyzes peptide bonds. -peptide bond: a bond that connects the acid end of one amino acid with the amino end of another, forming a link in a protein chain. -percent fat-free: may be used only if the product meets the definition of low fat or fat-free and must reflect the amount of fat in 100 g (for example, a food that contains 2.5 g of fat per 50 g can claim to be 95 percent fat free ). -peripheral (puh-riff-er-ul) nervous system: the peripheral (outermost) part of the nervous system; the vast complex of wiring that extends from the central nervous system to the body s outermost areas. -it contains both somatic and autonomic components. -peripheral resistance: the resistance to pumped blood in the small arterial branches (arterioles) that carry blood to tissues. -peristalsis (per-ih-stall-sis): wavelike muscular contractions of the gi tract that push its contents along. -pernicious (per-nish-us) anemia: a blood disorder that reflects a vitamin b12 deficiency caused by lack of intrinsic factor and characterized by abnormally large and immature red blood cells. -other symptoms include muscle weakness and irreversible neurological damage. -persistence: stubborn or enduring continuance; with respect to food contaminants, the quality of persisting, rather than breaking down, in the bodies of animals and human beings. -pesticides: chemicals used to control insects, weeds, fungi, and other pests on plants, vegetables, fruits, and animals. -used broadly, the term includes herbicides (to kill weeds), insecticides (to kill insects), and fungicides (to kill fungi). -ph: the unit of measure expressing a substance s acidity or alkalinity. -phagocytes (fag-oh-sites): white blood cells (neutrophils and macrophages) that have the ability to ingest and destroy foreign substances. -phagocytosis (fag-oh-sigh-toh-sis): the process by which phagocytes engulf and destroy foreign materials. -pharynx (fair-inks): the passageway leading from the nose and mouth to the larynx and esophagus, respectively. -phenylketonuria (fen-il-key-toe-new-ree-ah) or pku: an inherited disorder characterized by failure to metabolize the amino acid phenylalanine to tyrosine. -phospholipid (fos-foe-lip-id): a compound similar to a triglyceride but having a phosphate group (a phosphorus-containing salt) and choline (or another nitrogen-containing compound) in place of one of the fatty acids. -phosphorus: a major mineral found mostly in the body s bones and teeth. -photosynthesis: the process by which green plants use the sun s energy to make carbohydrates from carbon dioxide and water. -physical activity: bodily movement produced by muscle contractions that substantially increase energy expenditure. -physiological age: a person s age as estimated from her or his body s health and probable life expectancy. -phytic (fye-tick) acid: a nonnutrient component of plant seeds; also called phytate (fye-tate). -phytic acid occurs in the husks of grains, legumes, and seeds and is capable of binding minerals such as zinc, iron, calcium, magnesium, and copper in insoluble complexes in the intestine, which the body excretes unused. -phytochemicals (fie-toe-kem-ih-cals): nonnutrient compounds found in plant-derived foods that have biological activity in the body. -phytoestrogens: plant-derived compounds that have structural and functional similarities to human estrogen. -phytoestrogens include the isoflavones genistein, daidzein, and glycitein. -phytosterols: plant-derived compounds that have structural similarities to cholesterol and lower blood cholesterol by competing with cholesterol for absorption. -phytosterols include sterol esters and stanol esters. -pica (pie-ka): a craving for nonfood substances. -also known as geophagia (gee-oh-fay-gee-uh) when referring to clay eating and pagophagia (pag-oh- fay-gee-uh) when referring to ice craving. -pigment: a molecule capable of absorbing certain wavelengths of light so that it reflects only those that we perceive as a certain color. -placebo (pla-see-bo): an inert, harmless medication given to provide comfort and hope; a sham treatment used in controlled research studies. -placebo effect: a change that occurs in reponse to expectations in the effectiveness of a treatment that actually has no pharmaceutical effects. -placenta (plah-sen-tuh): the organ that develops inside the uterus early in pregnancy, through which the fetus receives nutrients and oxygen and returns carbon dioxide and other waste products to be excreted. -plant-pesticides: pesticides made by the plants themselves. -plaque (plack): an accumulation of fatty deposits, smooth muscle cells, and fibrous connective tissue that develops in the artery walls in atherosclerosis. -plaque associated with atherosclerosis is known as atheromatous (ath-er-oh-ma-tus) plaque. -platelets: tiny, disc-shaped bodies in the blood, important in blood clot formation. -point of unsaturation: the double bond of a fatty acid, where hydrogen atoms can easily be added to the structure. -polypeptide: many (ten or more) amino acids bonded together. -polysaccharides: compounds composed of many monosaccharides linked together. -an intermediate string of three to ten monosaccharides is an oligosaccharide. -polyunsaturated fatty acid (pufa): a fatty acid that lacks four or more hydrogen atoms and has two or more double bonds between carbons for example, linoleic acid (two double bonds) and linolenic acid (three double bonds). -a polyunsaturated fat is composed of triglycerides in which most of the fatty acids are polyunsaturated. -post term (infant): an infant born after the 42nd week of pregnancy. -postpartum amenorrhea: the normal temporary absence of menstrual periods immediately following childbirth. -potassium: the principal cation within the body s cells; critical to the maintenance of fluid balance, nerve impulse transmissions, and muscle contractions. -precursors: substances that precede others; with regard to vitamins, compounds that can be converted into active vitamins; also known as provitamins. -prediabetes: condition in which blood glucose levels are higher than normal but not high enough to be diagnosed as diabetes; considered a major risk factor for future diabetes and cardiovascular diseases; formerly called impaired glucose tolerance. -preeclampsia (pre-ee-klamp-see-ah): a condition characterized by hypertension, fluid retention, and protein in the urine; formerly known as pregnancy- induced hypertension. -preformed vitamin a: dietary vitamin a in its active form. -prehypertension: slightly higher-than-normal blood pressure, but not as high as hypertension (table 18-4). -prenatal alcohol exposure: subjecting a fetus to a pattern of excessive alcohol intake characterized by substantial regular use or heavy episodic drinking. -preservatives: antimicrobial agents, antioxidants, and other additives that retard spoilage or maintain desired qualities, such as softness in baked goods. -pressure ulcers: damage to the skin and underlying tissues as a result of compression and poor circulation; commonly seen in people who are bedridden or chairbound. -preterm (infant): an infant born prior to the 38th week of pregnancy; also called a premature infant. -a term infant is born between the 38th and 42nd week of pregnancy. -primary deficiency: a nutrient deficiency caused by inadequate dietary intake of a nutrient. -probiotics: living microorganisms found in foods that, when consumed in sufficient quantities, are beneficial to health. -processed foods: foods that have been treated to change their physical, chemical, microbiological, or sensory properties. -progesterone: the hormone of gestation (pregnancy). -progressive overload principle: the training principle that a body system, in order to improve, must be worked at frequencies, durations, or intensities that gradually increase physical demands. -prolactin (pro-lak-tin): a hormone secreted from the anterior pituitary gland that acts on the mammary glands to promote the production of milk. -the release of prolactin is mediated by prolactin- inhibiting hormone (pih). -promoters: factors that favor the development of cancers once they have begun. -proof: a way of stating the percentage of alcohol in distilled liquor. -liquor that is 100 proof is 50% alcohol; 90 proof is 45%, and so forth. -prooxidants: substances that significantly induce oxidative stress. -proteases (pro-tee-aces): enzymes that hydrolyze protein. -glossary gl-13 protein digestibility: a measure of the amount of amino acids absorbed from a given protein intake. -protein efficiency ratio (per): a measure of protein quality assessed by determining how well a given protein supports weight gain in growing rats; used to establish the protein quality for infant formulas and baby foods. -protein turnover: the degradation and synthesis of protein. -protein-energy malnutrition (pem), also called protein- kcalorie malnutrition (pcm): a deficiency of protein, energy, or both, including kwashiorkor, marasmus, and instances in which they overlap. -proteins: compounds composed of carbon, hydrogen, oxygen, and nitrogen atoms, arranged into amino acids linked in a chain. -some amino acids also contain sulfur atoms. -protein-sparing action: the action of carbohydrate (and fat) in providing energy that allows protein to be used for other purposes. -puberty: the period in life in which a person becomes physically capable of reproduction. -public health dietitians: dietitians who specialize in providing nutrition services through organized community efforts. -public water: water from a municipal or county water system that has been treated and disinfected. -purified water: water that has been treated by distillation or other physical or chemical processes that remove dissolved solids. -because purified water contains no minerals or contaminants, it is useful for medical and research purposes. -purines: compounds of nitrogen-containing bases such as adenine, guanine, and caffeine. -pyloric (pie-lore-ic) sphincter: the circular muscle that separates the stomach from the small intestine and regulates the flow of partially digested food into the small intestine; also called pylorus or pyloric valve. -pyruvate (pie-roo-vate): a 3-carbon compound that plays a key role in energy metabolism. -q qi gong (ch e gung): a chinese system that combines movement, meditation, and breathing techniques to enhance the flow of qi (vital energy) in the body. -quality of life: a person s perceived physical and mental well-being. -r randomization (ran-dom-ih-zay-shun): a process of choosing the members of the experimental and control groups without bias. -raw sugar: the first crop of crystals harvested during sugar processing. -raw sugar cannot be sold in the united states because it contains too much filth (dirt, insect fragments, and the like). -sugar sold as raw sugar domestically has actually gone through over half of the refining steps. -rd: see registered dietitian. -recommended dietary allowance (rda): the average daily amount of a nutrient considered adequate to meet the known nutrient needs of practically all healthy people; a goal for dietary intake by individuals. -rectum: the muscular terminal part of the intestine, extending from the sigmoid colon to the anus. -reduced kcalorie: at least 25% fewer kcalories per serving than the comparison food. -reference protein: a standard against which to measure the quality of other proteins. -gl-14 glossary refined: the process by which the coarse parts of a food are removed. -when wheat is refined into flour, the bran, germ, and husk are removed, leaving only the endosperm. -reflux: a backward flow. -registered dietitian (rd): a person who has completed a minimum of a bachelor s degree from an accredited university or college, has completed approved course work and a supervised practice program, has passed a national examination, and maintains registration through continuing professional education. -registration: listing; with respect to health professionals, listing with a professional organization that requires specific course work, experience, and passing of an examination. -relaxin: the hormone of late pregnancy. -remodeling: the dismantling and re-formation of a structure. -renin (ren-in): an enzyme from the kidneys that activates angiotensin. -rennin: an enzyme that coagulates milk; found in the gastric juice of cows, but not human beings. -replication (rep-lih-kay-shun): repeating an experiment and getting the same results. -requirement: the lowest continuing intake of a nutrient that will maintain a specified criterion of adequacy. -residues: whatever remains. -in the case of pesticides, those amounts that remain on or in foods when people buy and use them. -resistant starches: starches that escape digestion and absorption in the small intestine of healthy people. -risk factor: a condition or behavior associated with an elevated frequency of a disease but not proved to be causal. -leading risk factors for chronic diseases include obesity, cigarette smoking, high blood pressure, high blood cholesterol, physical inactivity, and a diet high in saturated fats and low in vegetables, fruits, and whole grains. -rna (ribonucleic acid): a compound similar to dna, but rna is a single strand with a ribose sugar instead of a deoxyribose sugar and uracil instead of thymine as one of its bases. -royal jelly: the substance produced by worker bees and fed to the queen bee; falsely promoted as increasing strength and enhancing performance. -s saccharin (sak-ah-ren): an artificial sweetener that has been approved for use in the united states. -in canada, approval for use in foods and beverages is pending; currently available only in pharmacies and only as a tabletop sweetener, not as an additive. -serotonin (ser-oh-tone-in): a neurotransmitter important in sleep regulation, appetite control, intestinal motility, obsessive-compulsive behaviors, and mood disorders. -set point: the point at which controls are set (for example, on a thermostat). -the set-point theory that relates to body weight proposes that the body tends to maintain a certain weight by means of its own internal controls. -sibutramine (sigh-byoo-tra-mean): a drug used in the treatment of obesity that slows the reabsorption of serotonin in the brain, thus suppressing appetite and creating a feeling of fullness. -sickle-cell anemia: a hereditary form of anemia characterized by abnormal sickle- or crescent- shaped red blood cells. -sickled cells interfere with oxygen transport and blood flow. -symptoms are precipitated by dehydration and insufficient oxygen (as may occur at high altitudes) and include hemolytic anemia (red blood cells burst), fever, and severe pain in the joints and abdomen. -safety: the condition of being free from harm or danger. -simple carbohydrates (sugars): monosaccharides saliva: the secretion of the salivary glands. -its principal enzyme begins carbohydrate digestion. -salivary glands: exocrine glands that secrete saliva into the mouth. -salt: a compound composed of a positive ion other than h+ and a negative ion other than oh(cid:2). -an example is sodium chloride (na+ cl(cid:2)). -salt sensitivity: a characteristic of individuals who respond to a high salt intake with an increase in blood pressure or to a low salt intake with a decrease in blood pressure. -sarcopenia (sar-koh-pee-nee-ah): loss of skeletal resting metabolic rate (rmr): similar to the basal muscle mass, strength, and quality. -metabolic rate (bmr), a measure of the energy use of a person at rest in a comfortable setting, but with less stringent criteria for recent food intake and physical activity. -consequently, the rmr is slightly higher than the bmr. -retina (ret-in-uh): the layer of light-sensitive nerve cells lining the back of the inside of the eye; consists of rods and cones. -retinoids (ret-ih-noyds): chemically related compounds with biological activity similar to that of retinol; metabolites of retinol. -retinol activity equivalents (rae): a measure of vitamin a activity; the amount of retinol that the body will derive from a food containing preformed retinol or its precursor beta-carotene. -retinol-binding protein (rbp): the specific protein responsible for transporting retinol. -rheumatoid (roo-ma-toyd) arthritis: a disease of the immune system involving painful inflammation of the joints and related structures. -rhodopsin (ro-dop-sin): a light-sensitive pigment of the retina; contains the retinal form of vitamin a and the protein opsin. -riboflavin (rye-boh-flay-vin): a b vitamin. -the coenzyme forms are fmn (flavin mononucleotide) and fad (flavin adenine dinucleotide). -satiating: having the power to suppress hunger and inhibit eating. -satiation (say-she-ay-shun): the feeling of satisfaction and fullness that occurs during a meal and halts eating. -satiation determines how much food is consumed during a meal. -satiety (sah-tie-eh-tee): the feeling of fullness and satisfaction that occurs after a meal and inhibits eating until the next meal. -satiety determines how much time passes between meals. -saturated fat-free: less than 0.5 g of saturated fat and 0.5 g of trans fat per serving. -saturated fatty acid: a fatty acid carrying the maximum possible number of hydrogen atoms for example, stearic acid. -a saturated fat is composed of triglycerides in which most of the fatty acids are saturated. -scurvy: the vitamin c deficiency disease. -secondary deficiency: a nutrient deficiency caused by something other than an inadequate intake such as a disease condition or drug interaction that reduces absorption, accelerates use, hastens excretion, or destroys the nutrient. -secretin (see-creet-in): a hormone produced by cells in the duodenum wall. -target organ: the pancreas. -response: secretion of bicarbonate-rich pancreatic juice. -ribose: a 5-carbon sugar falsely promoted as sedentary: physically inactive (literally, sitting down improving the regeneration of atp and thereby the speed of recovery after high-power exercise. -ribosomes (rye-boh-zomes): protein-making organelles in cells; composed of rna and protein. -a lot ). -segmentation (seg-men-tay-shun): a periodic squeezing or partitioning of the intestine at intervals along its length by its circular muscles. -rickets: the vitamin d deficiency disease in children selenium (se-leen-ee-um): a trace element. -characterized by inadequate mineralization of bone (manifested in bowed legs or knock-knees, outward-bowed chest, and knobs on ribs). -a rare type of rickets, not caused by vitamin d deficiency, is known as vitamin d refractory rickets. -risk: a measure of the probability and severity of harm. -senile dementia: the loss of brain function beyond the normal loss of physical adeptness and memory that occurs with aging. -senile plaques: clumps of the protein fragment beta- amyloid on the nerve cells, commonly found in the brains of people with alzheimer s dementia. -and disaccharides. -small intestine: a 10-foot length of small-diameter intestine that is the major site of digestion of food and absorption of nutrients. -its segments are the duodenum, jejunum, and ileum. -socioeconomic history: a record of a person s social and economic background, including such factors as education, income, and ethnic identity. -sodium: the principal cation in the extracellular fluids of the body; critical to the maintenance of fluid balance, nerve impulse transmissions, and muscle contractions. -sodium bicarbonate: baking soda; an alkaline salt believed to neutralize blood lactic acid and thereby to reduce pain and enhance possible workload. -soda loading may cause intestinal bloating and diarrhea. -sodium-free and salt-free: less than 5 mg of sodium per serving. -soft water: water with a high sodium or potassium content. -solanine (soh-lah-neen): a poisonous narcotic-like substance present in potato peels and sprouts. -soluble fibers: indigestible food components that dissolve in water to form a gel. -an example is pectin from fruit, which is used to thicken jellies. -solutes (soll-yutes): the substances that are dissolved in a solution. -the number of molecules in a given volume of fluid is the solute concentration. -somatic (so-mat-ick) nervous system: the division of the nervous system that controls the voluntary muscles, as distinguished from the autonomic nervous system, which controls involuntary functions. -somatostatin (ghih): a hormone that inhibits the release of growth hormone; the opposite of somatotropin (gh). -soup kitchens: programs that provide prepared meals to be eaten on site. -sperm: the male reproductive cell, capable of fertilizing an ovum. -sphincter (sfink-ter): a circular muscle surrounding, and able to close, a body opening. -sphincters are found at specific points along the gi tract and regulate the flow of food particles. -spina (spy-nah) bifida (biff-ih-dah): one of the most common types of neural tube defects; characterized by the incomplete closure of the spinal cord and its bony encasement. -spirulina: a kind of alga ( blue-green manna ) that supposedly contains large amounts of protein and vitamin b12, suppresses appetite, and improves athletic performance. -it does none of these things and is potentially toxic. -sports anemia: a transient condition of low sulfur: a mineral present in the body as part of some tocopherol (tuh-koff-er-ol): a general term for glossary gl-15 hemoglobin in the blood, associated with the early stages of sports training or other strenuous activity. -spring water: water originating from an underground spring or well. -it may be bubbly (carbonated), or flat or still, meaning not carbonated. -brand names such as spring pure do not necessarily mean that the water comes from a spring. -starches: plant polysaccharides composed of glucose. -sterile: free of microorganisms, such as bacteria. -sterols (stare-ols or steer-ols): compounds containing a four ring carbon structure with any of a variety of side chains attached. -stevia (stee-vee-ah): a south american shrub whose leaves are used as a sweetener; sold in the united states as a dietary supplement that provides sweetness without kcalories. -stomach: a muscular, elastic, saclike portion of the digestive tract that grinds and churns swallowed food, mixing it with acid and enzymes to form chyme. -stools: waste matter discharged from the colon; also called feces (fee-seez). -stress: any threat to a person s well-being; a demand placed on the body to adapt. -stress fractures: bone damage or breaks caused by stress on bone surfaces during exercise. -stress response: the body s response to stress, mediated by both nerves and hormones. -stressors: environmental elements, physical or psychological, that cause stress. -stroke: an event in which the blood flow to a part of the brain is cut off; also called cerebrovascular accident (cva). -structure-function claims: statements that characterize the relationship between a nutrient or other substance in a food and its role in the body. -subclavian (sub-klay-vee-an) vein: the vein that provides passageway from the lymphatic system to the vascular system. -subclinical deficiency: a deficiency in the early stages, before the outward signs have appeared. -subjects: the people or animals participating in a research project. -successful weight-loss maintenance: achieving a weight loss of at least 10 percent of initial body weight and maintaining the loss for at least one year. -sucralose (sue-kra-lose): an artificial sweetener approved for use in the united states and canada. -sucrase: an enzyme that hydrolyzes sucrose. -sucrose (sue-krose): a disaccharide composed of glucose and fructose; commonly known as table sugar, beet sugar, or cane sugar. -sucrose also occurs in many fruits and some vegetables and grains. -sudden infant death syndrome (sids): the unexpected and unexplained death of an apparently well infant; the most common cause of death of infants between the second week and the end of the first year of life; also called crib death. -sugar replacers: sugarlike compounds that can be derived from fruits or commercially produced from dextrose; also called sugar alcohols or polyols. -sugar alcohols are absorbed more slowly than other sugars and metabolized differently in the human body; they are not readily utilized by ordinary mouth bacteria. -examples are maltitol, mannitol, sorbitol, xylitol, isomalt, and lactitol. -sugar-free: less than 0.5 g of sugar per serving. -sulfate: the oxidized form of sulfur. -sulfites: salts containing sulfur that are added to foods to prevent spoilage. -proteins. -supplement: any pill, capsule, tablet, liquid, or powder that contains vitamins, minerals, herbs, or amino acids; intended to increase dietary intake of these substances. -sushi: vinegar-flavored rice and seafood, typically wrapped in seaweed and stuffed with colorful vegetables. -some sushi is stuffed with raw fish; other varieties contain cooked seafood. -sustainable: able to continue indefinitely; using resources at such a rate that the earth can keep on replacing them and producing pollutants at a rate with which the environment and human cleanup efforts can keep pace, so that no net accumulation of pollution occurs. -sustainable agriculture: agricultural practices that use individualized approaches appropriate to local conditions so as to minimize technological, fuel, and chemical inputs. -synergistic (sin-er-jis-tick): multiple factors operating together in such a way that their combined effects are greater than the sum of their individual effects. -t tagatose (tag-ah-tose): a monosaccharide structurally similar to fructose that is incompletely absorbed and thus provides only 1.5 kcalories per gram; approved for use as a generally recognized as safe ingredient. -tca cycle or tricarboxylic (try-car-box-ill-ick) acid cycle: a series of metabolic reactions that break down molecules of acetyl coa to carbon dioxide and hydrogen atoms; also called the kreb s cycle after the biochemist who elucidated its reactions. -several chemically related compounds, one of which has vitamin e activity. -tofu (toe-foo): a curd made from soybeans, rich in protein and often fortified with calcium; used in many asian and vegetarian dishes in place of meat. -tolerable upper intake level (ul): the maximum daily amount of a nutrient that appears safe for most healthy people and beyond which there is an increased risk of adverse health effects. -tolerance level: the maximum amount of residue permitted in a food when a pesticide is used according to the label directions. -toxicity: the ability of a substance to harm living organisms. -all substances are toxic if high enough concentrations are used. -trabecular (tra-beck-you-lar) bone: the lacy inner structure of calcium crystals that supports the bone s structure and provides a calcium storage bank. -trace minerals: essential mineral nutrients found in the human body in amounts smaller than 5 g; sometimes called microminerals. -trachea (trake-ee-uh): the air passageway from the larynx to the lungs; also called the windpipe. -training: practicing an activity regularly, which leads to conditioning. -(training is what you do; conditioning is what you get.) -trans fat-free: less than 0.5 g of trans fat and less than 0.5 g of saturated fat per serving. -transamination (trans-am-ih-nay-shun): the transfer of an amino group from one amino acid to a keto acid, producing a new nonessential amino acid and a new keto acid. -t-cells: lymphocytes that attack antigens. -t stands for trans-fatty acids: fatty acids with hydrogens on the thymus gland, where the t-cells mature. -opposite sides of the double bond. -tempeh (tem-pay): a fermented soybean food, rich transferrin (trans-fair-in): the iron transport protein. -in protein and fiber. -teratogenic (ter-at-oh-jen-ik): causing abnormal fetal development and birth defects. -testosterone: a steroid hormone from the testicles, or testes. -the steroids, as explained in chapter 5, are chemically related to, and some are derived from, the lipid cholesterol. -textured vegetable protein: processed soybean protein used in vegetarian products such as soy burgers; see also meat replacements. -theory: a tentative explanation that integrates many and diverse findings to further the understanding of a defined topic. -thermic effect of food (tef): an estimation of the energy required to process food (digest, absorb, transport, metabolize, and store ingested nutrients); also called the specific dynamic effect (sde) of food or the specific dynamic activity (sda) of food. -thermogenesis: the generation of heat; used in physiology and nutrition studies as an index of how much energy the body is expending. -thiamin (thigh-ah-min): a b vitamin. -the coenzyme form is tpp (thiamin pyrophosphate). -thirst: a conscious desire to drink. -thoracic (thor-ass-ic) duct: the main lymphatic vessel that collects lymph and drains into the left subclavian vein. -thrombosis (throm-boh-sis): the formation of a thrombus (throm-bus), or a blood clot, that may obstruct a blood vessel, causing gradual tissue death. -thyroid-stimulating hormone (tsh): a hormone secreted by the pituitary that stimulates the thyroid gland to secrete its hormones thyroxine and triiodothyronine. -the release of tsh is mediated by tsh-releasing hormone (trh). -transient hypertension of pregnancy: high blood pressure that develops in the second half of pregnancy and resolves after childbirth, usually without affecting the outcome of the pregnancy. -transient ischemic (is-key-mik) attack (tia): a temporary reduction in blood flow to the brain, which causes temporary symptoms that vary depending on the part of the brain affected. -common symptoms include light-headedness, visual disturbances, paralysis, staggering, numbness, and inability to swallow. -travelers diarrhea: nausea, vomiting, and diarrhea caused by consuming food or water contaminated by any of several organisms, most commonly, e. coli, shigella, campylobacter jejuni, and salmonella. -triglycerides (try-gliss-er-rides): the chief form of fat in the diet and the major storage form of fat in the body; composed of a molecule of glycerol with three fatty acids attached; also called triacylglycerols (try-ay-seel-gliss-er-ols). -tripeptide: three amino acids bonded together. -tumor: an abnormal tissue mass with no physiological function; also called a neoplasm (nee-oh-plazm). -turbinado (ter-bih-nod-oh) sugar: sugar produced using the same refining process as white sugar, but without the bleaching and anti-caking treatment. -traces of molasses give turbinado its sandy color. -type 1 diabetes: the type of diabetes that accounts for 5 to 10% of diabetes cases and usually results from autoimmune destruction of pancreatic beta cells. -in this type of diabetes, the pancreas produces little or no insulin. -type 2 diabetes: the type of diabetes that accounts for 90 to 95% of diabetes cases and usually results from insulin resistance coupled with insufficient insulin secretion. -obesity is present in 80 to 90% of cases. -gl-16 glossary type i osteoporosis: osteoporosis characterized by rapid bone losses, primarily of trabecular bone. -vasoconstrictor (vas-oh-kon-strik-tor): a substance that constricts or narrows the blood vessels. -type ii osteoporosis: osteoporosis characterized by gradual losses of both trabecular and cortical bone. -u ulcer: a lesion of the skin or mucous membranes characterized by inflammation and damaged tissues. -ultrahigh temperature (uht) treatment: sterilizing a food by brief exposure to temperatures above those normally used. -umbilical (um-bill-ih-cul) cord: the ropelike structure through which the fetus s veins and arteries reach the placenta; the route of nourishment and oxygen to the fetus and the route of waste disposal from the fetus. -the scar in the middle of the abdomen that marks the former attachment of the umbilical cord is the umbilicus (um-bill-ih-cus), commonly known as the belly button. -undernutrition: deficient energy or nutrients. -underweight: body weight below some standard of acceptable weight that is usually defined in relation to height (such as bmi); bmi below 18.5. unsaturated fatty acid: a fatty acid that lacks hydrogen atoms and has at least one double bond between carbons (includes monounsaturated and polyunsaturated fatty acids). -an unsaturated fat is composed of triglycerides in which most of the fatty acids are unsaturated. -unspecified eating disorders: eating disorders that do not meet the defined criteria for specific eating disorders. -urea (you-ree-uh): the principal nitrogen-excretion product of protein metabolism. -two ammonia fragments are combined with carbon dioxide to form urea. -usda (u.s. department of agriculture): the federal agency responsible for enforcing standards for the wholesomeness and quality of meat, poultry, and eggs produced in the united states; conducting nutrition research; and educating the public about nutrition. -uterus (you-ter-us): the muscular organ within which the infant develops before birth. -v validity (va-lid-ih-tee): having the quality of being founded on fact or evidence. -variables: factors that change. -a variable may depend on another variable (for example, a child s height depends on his age), or it may be independent (for example, a child s height does not depend on the color of her eyes). -sometimes both variables correlate with a third variable (a child s height and eye color both depend on genetics). -variety (dietary): eating a wide selection of foods within and among the major food groups. -vegans (vee-gans): people who exclude all animal- derived foods (including meat, poultry, fish, eggs, and dairy products) from their diets; also called pure vegetarians, strict vegetarians, or total vegetarians. -vegetarians: a general term used to describe people who exclude meat, poultry, fish, or other animal- derived foods from their diets. -veins (vanes): vessels that carry blood to the heart. -very low sodium: 35 mg or less per serving. -villi (vill-ee, vill-eye): fingerlike projections from the folds of the small intestine; singular villus. -viscous: a gel-like consistency. -vitamin a: all naturally occurring compounds with the biological activity of retinol (ret-ih-nol), the alcohol form of vitamin a. vitamin a activity: a term referring to both the active forms of vitamin a and the precursor forms in foods without distinguishing between them. -vitamin b12: a b vitamin characterized by the presence of cobalt. -the active forms of coenzyme b12 are methylcobalamin and deoxyadenosylcobalamin. -vitamin b6: a family of compounds pyridoxal, pyridoxine, and pyridoxamine. -the primary active coenzyme form is plp (pyridoxal phosphate). -vitamins: organic, essential nutrients required in small amounts by the body for health. -weight management: maintaining body weight in a healthy range by preventing gradual weight gain over time and losing weight if overweight. -weight training (also called resistance training): the use of free weights or weight machines to provide resistance for developing muscle strength and endurance. -a person s own body weight may also be used to provide resistance as when a person does push-ups, pull-ups, or abdominal crunches. -well water: water drawn from ground water by tapping into an aquifer. -wernicke-korsakoff (ver-nee-key kore-sah-kof) syndrome: a neurological disorder typically associated with chronic alcoholism and caused by a deficiency of the b vitamin thiamin; also called alcohol-related dementia. -whey protein: a by-product of cheese production; falsely promoted as increasing muscle mass. -whey is the watery part of milk that separates from the curds. -white sugar: pure sucrose or table sugar, produced by dissolving, concentrating, and recrystallizing raw sugar. -whole grain: a grain milled in its entirety (all but the husk), not refined. -wine: an alcoholic beverage made by fermenting grape juice. -who (world health organization): an international agency concerned with promoting health and eradicating disease. -world wide web (the web, commonly abbreviated vldl (very-low-density lipoprotein): the type of www): a graphical subset of the internet. -lipoprotein made primarily by liver cells to transport lipids to various tissues in the body; composed primarily of triglycerides. -vo2max: the maximum rate of oxygen consumption by an individual at sea level. -x xanthophylls (zan-tho-fills): pigments found in plants; responsible for the color changes seen in autumn leaves. -vomiting: expulsion of the contents of the stomach up through the esophagus to the mouth. -xerophthalmia (zer-off-thal-mee-uh): progressive blindness caused by severe vitamin a deficiency. -xerosis (zee-row-sis): abnormal drying of the skin and mucous membranes; a sign of vitamin a deficiency. -y yogurt: milk product that results from the fermentation of lactic acid in milk by lactobacillus bulgaricus and streptococcus thermophilus. -z zygote (zy-goat): the product of the union of ovum and sperm; so-called for the first two weeks after fertilization. -w waist circumference: an anthropometric measurement used to assess a person s abdominal fat. -warm-up: 5 to 10 minutes of light activity, such as easy jogging or cycling, prior to a workout to prepare the body for more vigorous activity. -water balance: the balance between water intake and output (losses). -water intoxication: the rare condition in which body water contents are too high in all body fluid compartments. -wean: to gradually replace breast milk with infant formula or other foods appropriate to an infant s diet. -websites: internet resources composed of text and graphic files, each with a unique url (uniform resource locator) that names the site (for example, www.usda.gov). -index page references in bold indicate definitions of terms. -(see also glossary, gl-1 to gl-18) page references followed by the letter f indicate figures or photographs. -page references followed by the letter t indicate tables. -page references followed by the letter n indicate footnotes. -page references with combined letter and number (a-1) refer to the appendixes. -a abdominal fat, 262 263 see also central obesity abortion, spontaneous, 544 absorption, 71, 80 83 by active transport, 81f, 108 of alcohol, 240 by facilitated diffusion, 81f, 108 gi anatomy and, 79f, 80 83, 81f, 82f of medications, 616 medications and, 616, 616t olestra and, 165 regulation of, 86 88 by simple diffusion, 81f vascular system and, 82f see also digestion; glycemic index; transport (nutrient); specific nutrients acceptable daily intake (adi), 132, 133t, 135 acceptable macronutrient distribution ranges (amdr), 18 accidental additives, 685 accredited (schools), 32, 33, 33n accutane, 374 acesulfame potassium (acesulfame-k), 132, 133t, 134 acetaldehyde, 239, 240, 240f, 244, 336 acetaldehyde dehydrogenase, 240f, 241, 241f acetic acid, 108n, 140f, b-6 acetone, 235, 235f acetylcholine, 345, 606 acetyl coa, 218 amino acid metabolism and, 225, 225f b vitamins and, 334, 335, 347f, 348 fat metabolism and, 222, 223f, 224f fatty liver and, 241 glucose metabolism and, 221 222, 221f tca cycle and, 227 228, 227n, 228f, 231f acid-base balance, 113, 406 408 alcohol and, 241 ammonia and, 225 hydrochloric acid, 413 ketosis and, 113 ph scale and, 407f regulation of, 191, 406 408, 408f, 410n vomiting and, 412, 413n see also ph acid controllers, 94, 96 97 acid indigestion, 96 97, 97t acidosis, 191, 407f acids, 191, b-6 see also ph acne (and vitamin a), 374 acrodermatitis enteropathica, 455n acrylamide, 644 645, 685 686 acth (adrenocorticotropin), a-3, a-4, a-5 active transport, 81f, 108, 192f acupuncture, 653, 656t acute disease, 3 acute pem, 197 ada. -see american dietetic association (ada) adaptive thermogenesis, 254, 256, 307 addictions. -see cravings additives, 682 687 antioxidants, 143, 143n, 684 cancer risk, 643 indirect or incidental, 685 687 intentional food additives, 683 685, 683t nutrient additives, 354, 685 regulation of, 136, 682 683 sodium in, 412 sugar alternatives, 132 137, 133t, 134f, 136t, 137f sugar as, 117 121 see also food industry adenomas, 642 adenosine diphosphate (adp), 217f, c-9f adenosine triphosphate. -see atp adequacy (dietary), 37, 39, 673 674 adequate intake (ai), 17 18, 18f, 19, inside front cover adh (antidiuretic hormone), 239, a-3 alcohol and, 243 blood volume regulation, 403f, a-5 function of, 191t water retention and, 401 adhd (attention-deficit/hyperactivity disorder), 564 adipokines, 265 adipose tissue, 155 cell structure, 155f composition of, 250 estrogen synthesis, 266 exercise and, 301 lipoprotein lipase, 155, 282 283 metabolism in, 282 283 number and size of cells, 282, 283f, 284 white vs. brown, 286 see also fats (body) adolescence, 575 580 alcohol/drug use, 245, 579 bone density and, 435 calcium needs, 418 diabetes in, 115 eating disorders, 271, 276 iron deficiency and, 446 nutrition during, 575 580 obesity surgery, 292 293 overweight, 115, 120, 281 pregnancy during, 529 smoking/tobacco use, 579 580, 589 soft drinks, 568 websites on, 580 581 adp (adenosine diphosphate), 217f, c-9f adrenal glands, 352, 401, 406, a-5, a-6 adrenaline. -see epinephrine adrenocorticotropin (acth), a-3, a-4, a-5 adult bone loss, 421 adverse reactions, 566 to drugs. -see nutrient-drug interactions to foods, 566, 684, 685, 690 to herbs, 658 advertising of antioxidants, 390 of chromium supplements, 461 food industry, 287, 569 ftc policies, 365 laxatives, 95 obesity and, 569 signs of quackery, 33, 34f of supplements, 203, 362, 363 364, 365, 503, 504 aerobic, defined, 220 aerobic activity carbohydrate use and, 221, 486, 490 cardiorespiratory training, 480t, 482 483, 483f fat use and, 489 protein use and, 490 african americans/blacks bone density, 260 eclampsia/preeclampsia, 528, 529 life expectancy, 593 nonfood cravings and, 525 osteoporosis and, 435 vitamin d and, 380 age, chronological, 595 age, physiological, 595 aging (older adults), 593 611 arthritis, 605 606 bone mass, 379, 421f, 433 434, 433f, 434f, 603. see also osteoporosis cognitive function and, 606 607 constipation, 602 energy needs, 256 exercise and, 478, 484, 595 596, 596t fiber and, 602 food choices/eating habits, 607 611 health strategies for, 608t heart disease risk, 628, 631 hypertension and, 634 longevity and nutrition, 593 597 medications and, 615 national institute on aging, 437 nutrient concerns, 601 604, 604t, 606t physiological changes, 598 600 population statistics, 593, 594f setting dri for, 601 vision problems, 604 605 vitamin d deficiency, 378 379 water needs of, 398, 601 websites on, 611 612 agribusiness, 716, 720 agriculture, 716 720 antibiotic resistance, 687 biopharming, 695 biotechnology, 693 697, 697t bovine growth hormone (bgh), 686 687 energy use, 717 718, 718f, 718t, 719f environmental degradation, 710, 716 717 genetic diversity, loss of, 710, 717 genetic engineering, 693 697, 694f, 697t limitations to food production, 710 livestock, 668 669, 676, 710, 716, 717f, 718, 719, 719f livestock, grass-fed, 162, 177, 718, 719 organically grown crops, 7, 680 681, 681f overpopulation and, 710 pbb contaminated meat, 676 pesticides, 678 681, 695, 716, 718t in-2 index agriculture, continued pesticides, alternatives to, 680 sustainable, 716, 717 720, 718t, 719f websites on, 697 see also usda (u.s. department of agriculture) ai. -see adequate intake (ai) aids (acquired immune deficiency syndrome), 536 537, 623 624, 624t air displacement plethysmography, 264f alanine, 182f albumin, serum, e-19n, e-19t alcohol, 238 247, 239 absorption of, 240 amount in beverages, 238 240, 244t blood levels, 242, 243t blood sugar and, 246t brain, effects on, 242 243, 242f, 243t, 543 cancer and, 244, 246t, 643, 644t death associated with, 25t, 242, 244, 245 diabetes and, 641 dietary guidelines and, 40t, 43f as diuretic, 400 drugs and, 242 effects, long-term, 245, 246t effects, short-term, 244, 400, 496 ethanol, defined, 239 exercise and, 496 fertility and, 545 fetal development/pregnancy, 530, 543 545, 543f, 545f health benefits of, 238 heart disease and, 244, 246t, 632t hypertension and, 635 intake appropriate, 40t, 43f, 238 240, 245, 247 kcalories in, 8, 9t, 243, 244t lactation and, 537 liver and, 240 242, 246t malnutrition and, 243 244, 246t metabolism of, 240 242, 241f, 242f myths concerning, 245, 246t nutrient imbalances and, 579 obesity and, 243, 246t personal strategies for, 245, 247 serotonin and, 120 structure of, 102f, 238f tca cycle and, c-15 tolerance for, 239, 240 vitamin deficiencies and, 244, 327, 336 websites on, 247, 545 weight control and, 298 alcohol abuse, 239 by adolescents, 245, 579 binge drinking, 244 245 deficiencies and, 327, 336, 338 disease risks and, 246t effects overview, 244 245 fetal alcohol syndrome, 543 545, 543f, 545f healthy people 2010 goals, j-2t heart disease and, 244, 246t iron overload and, 448 malnutrition and, 243 244, 246t osteoporosis and, 435 paternal, and low birthweight, 545 tissue damage from, 240 websites on, 247 alcohol dehydrogenase, 239, 240, 240f, 241f alcoholism, 239 health effects of, 246t malnutrition and, 243 244, 246t signs of, 245t websites on, 247 alcohol-related birth defects (arbd), 543, 544 alcohol-related neurodevelopmental disorder (arnd), 543, 544 aldosterone, 401, a-3 blood volume regulation, 401 402, 403f fluids and electrolyte balance, 406 functions of, a-6 alendronate, 434n alitame, 132, 133n, 133t, 135 alkaline phosphatase, 452n alkalosis, 191, 407f, 413, 413n alkylresorcinols, 470t allergies, 565 567 asymptomatic vs. symptomatic, 565 breast milk and, 536, 552 food allergies, defined, 565 formulas for infants with, 553 gm foods and, 696 prevention of, in infants, 555 556 vs. adverse reactions to foods, 566 567 websites on, 581 see also adverse reactions almonds, 173 aloe vera, 654f, 657t alpha-carotene, 370n, 470n alpha cells (pancreas), 113n alpha-lactalbumin, 550 alpha-linolenic acid, 154n alpha-tocopherol, 380, 383, 393, c-9f see also vitamin e alternative agriculture, 680 681 alternative medicine, 652 659 see also complementary and alternative medicine alzheimer s disease, 606 607, 606n, 612 amdr (acceptable macronutrient distribution ranges), 18 amenorrhea, 270 bone loss and, 434 in eating disorders, 271, 271f, 273 postpartum, 537 primary and secondary, 270 american dietetic association (ada), 31, 32, 573, 696, 703, 711 american heart association, 33 american journal of clinical nutrition, 33 amino acid pool, 193 amino acids, 181 183 absorption of, 185, 186f alcohol s effect on, 241 body protein breakdown and, 193 194 branched-chain, 203 conditionally essential, 183 deamination of, 194 endogenous vs. exogenous, 193 energy metabolism, 193, 194, 224 226, 225f, 226f, 347f, c-11 to c-13f essential, 182t, 183, 195, 196, 343n, d-1t fat synthesis, 194 functions of, 188f, 193 194 glucogenic, 194n, 221f, 225, 225f hydrophilic vs. hydrophobic, 184 indispensable/dispensable, 183 ketogenic, 194n, 221f, 225, 225f, 226f limiting, 195 listed, 182t melanin synthesis, 194 neurotransmitter synthesis, 194 niacin synthesis, 194 nonessential, 182, 182t, 194, 225, 225f, 226, 226f pdcaas, d-1 to d-2, d-2t protein-sparing action of carbohydrate, 193n in protein synthesis, 183 184, 183f, 184f, 194, 195 structure of, 181 182, 182f, 183f, c-4f sulfur and, 425, 427 supplements, 185, 202 203, 202n synthesis of, 194, 225, 225f, 226, 226f, 336 thyroxin synthesis, 194 see also specific amino acids amino acid scoring, d-1, d-1t aminopeptidases, in protein digestion, 186f ammonia, 225, b-3 to b-4, b-6 amniotic fluid, 518f amniotic sac, 510, 511f amphetamines, 616 amylases, 108 amylopectin, 106f, c-2f amylose, 106f, c-2f anabolic steroids, 503, 505, 506t anabolism, 214, 215f anaerobic, defined, 220 anaerobic metabolism, 220, 220f, 221, 485, 485t anaphylactic shock, 566 androstenedione, 506 anecdotes, 11 anemia, 189, 341 assessment of, e-19 to e-22, e-20t, e-21t causes of, 341, 348 in children, 560, 563 folate and, 341, e-20t, e-22, e-22t goat s milk, 341, 553 hemolytic, 382 iron-deficiency. -see iron-deficiency anemia lead poisoning and, 564 macrocytic (megaloblastic), 341 microcytic, 337n, 355n microcytic hypochromic, 446 milk anemia, 557 pernicious, 343, 344f red blood cells in, 189, 189f, 344f, 446, 447f sickle-cell, 189, 189f sports anemia, 493 vitamin b12 deficiency, 343 344, 344f, e-20t, e-22, e-22t anencephaly, 513 aneurysms, 626, 627 angina, 626, 627 angiotensin, 401, 403f, a-3, a-6 angiotensinogen, 401 angular stomatitis, 330n animal foods vs. plant foods agriculture and, 717f, 718 719, 719f bone health and, 200 fossil fuel use, 717, 719f heart disease and, 65, 144f, 157, 199 animal studies, 13f, 285f, 596 597 anions, 403, 404t, 405f anorexia nervosa, 270 overview of, 307 binge eating and, 276 bone loss and, 434 diagnosis/intervention, 272 274, 273t ghrelin and, 285 malnutrition and, 197, 273 overriding hunger, 251 252 websites on, 277 see also eating disorders antacids, 94, 431 calcium and, 436 criteria for use, 96 97 folate and, 341 nutrient absorption and, 616 antagonists, 336 anthropometric measurements, 21, 264f, 548, e-5 to e-16, e-5t, e-6f to e-15f, e-16t antibiotics as incidental food additives, 687 nutrient-drug interactions, 616 for older adults, 599 resistance to, 687 sodium in, 618 vitamin k and, 383 antibodies, 192, 622 see also immune system anticoagulants, 354, 383 antidiuretic hormone. -see adh antigens, 192, 622 antimicrobial agents, 683 684, 683t antioxidants, 143, 351, 390 393 alzheimer s disease and, 607 for athletes, 492 beta-carotene, 372, 391 cancer risk and, 391 392, 645 as food additives, 143, 683t, 684 food sources, 393 free radicals and, 351f in fruits/vegetables, 391 392 heart disease and, 392, 393 mechanism of action, 351, 351f, 391, 391f in mediterranean diet, 597 older adults and, 605, 607 phytochemicals as, 391, 469 470, 470t, 471 as prooxidants, 393 rheumatoid arthritis and, 605 selenium as, 457 slowing aging, 597, 598 smokers and, 580 supplements and, 364, 390, 392 393 vitamin c, 351, 351f, 352, 354, 391, 391f vitamin e, 382, 391 antipromoters (cancer), 642, 645 antiscorbutic factor, 351 anus, 72, 73f, 76 appendicitis and fiber, 122 appendix, 72, 73f, 74 appetite, 251 alcohol and, 243 artificial sweeteners and, 135 drugs/herbs and, 292, 579, 615 616 exercise and, 301 factors affecting, 251 253 fasting/starvation and, 235 fruit vs. juice, 53 ghrelin and, 285, 286 leptin and, 284 smoking and, 579 see also hunger (sensation); satiety appropriate for gestational age (aga), 526 arabinose, c-3f arachidonic acid, 154, 154f, 155, 159t, 550 arbd (alcohol-related birth defects), 543, 544 arginine, 199 200, 504 ariboflavinosis, 329 aristolochia fangchi, 658 arnd (alcohol-related neurodevelopmental disorder), 543, 544 aroma therapy, 653 arsenic, 462 arteries, 83, 84f see also atherosclerosis; vascular system artesian water, 400 arthritis, 246t, 605 606, 612 artificial colors, 683t, 684 685 artificial fats, 164 165 artificial flavors, 685 artificial sweeteners, 132 138, 133t, 134f, 135t, 137f, 532 ascorbic acid. -see vitamin c -ase (word ending), 77, 108 asian americans, ethnic cuisine of, 46t aspartame, 132, 133 134, 133n, 133t, 134f, 135, 135t aspartic acid, 182f aspirin, 154, 341, 615, 616 assessment of nutrition status. -see nutrition assessment -ate (word ending), 218n, 404 atheromatous plaques, 587, 626 atherosclerosis, 147, 586 587, 626 antioxidants and, 392 atherogenic diet, 629 630 cholesterol and, 147 development of, 586 587, 587f, 626 628 in diabetics, 640 risk factors for, 629 630 see also cardiovascular disease (cvd); cholesterol; coronary heart disease (chd) athletes, 477 507 amenorrhea in, 271, 271f body composition, 258, 259, 261 262, 310 311 body image, 272 calcium for, 271 carbohydrate intake, 486 488, 499 carbohydrate loading, 487 diet planning for, 496 499, 498f eating disorders in, 271f, 310 311 energy expenditure, 255t, 257t fat intake, 161, 488 489 female athlete triad, 270, 271f fluids and electrolytes for, 271 272, 493 496, 494t food/fluid restriction, 271 272, 398, 492 glucose supply, maximizing, 487 488, 488t iron and, 492 493 osteoporosis in, 271, 271f pregame/postgame meals, 497 499, 498f protein needs, 201, 490 491, 491t, 497 sodium and, 398, 412 steroid use by, 505 506, 506t stress fractures in, 270, 271 supplements for, 202, 492, 497, 503 506, 506t vegetarians, 492 vitamin/mineral needs, 491 493 weight standards, 271 272, 492 weight training, 481 see also physical activity atkins diet, 317t atoms, properties of, 102, 102f, b-1 to b-3, b-2t atp (adenosine triphosphate), 216 coupled reactions, 216, 217f energy for exercise, 484 485, 485t energy metabolism central pathways, 231f energy transfer and, 216 glucose metabolism and, 219f 222f, 220, 220n, c-15n, c-15t structure of, 216f, c-9f see also tca (krebs) cycle atrophic gastritis, 343, 599 atrophy (muscle), 481 attention-deficit/hyperactivity disorder (adhd), 564 autoimmune disorders, 638 autonomic nervous system, a-7 to a-8, a-8f available carbohydrates, 108 avian influenza, 669 avidin, 334 ayurveda, 653, 656 b bacteria antimicrobial agents, 683 684, 683t dental caries and, 119 e. coli infection, 665t, 666 gastrointestinal. -see intestinal bacteria helicobacter pylori, 97, 343 lactobacillus bifidus, 86, 551 552 probiotics, 86 ulcers and, 13f, 97, 343 vitamins produced by, 86 water contamination, 672 see also foodborne illnesses; infections/ infectious disease balance (dietary), 38 bariatrics, 292 barrett s esophagus, 97 index in-3 basal metabolic rate (bmr), 254 exercise and, 255t, 300 factors affecting, 254 256, 255t infants, 254 obesity and uncoupling proteins, 286 in older adults, 601 thyroid hormones and, 455 websites on, 266 basal metabolism, 254, 254f, 255t bases, 191, b-6 b-cells, 622 beans, 43f, 47f, 52f, 677 see also legumes; soy products beauty. -see body image beer, 238, 239, 244, 244t, 496, 684 behavior of children, 120, 562, 563, 564 565 fetal alcohol syndrome and, 543 hunger and, 562 564 hyperactivity, 564 565 nutrient deficiencies and, 447, 562, 563 sugar and, 120 violence and alcohol, 245 see also lifestyle choices behavior modification, for weight loss, 303, 571 beikost, 555 belching, 94, 95 96, 97t benzopyrene, 644n beriberi, 327, 328f beta-carotene, 369 377 as antioxidant, 372, 391 cancer and, 372, 580 overconsumption of, 374, 375f, 377n as prooxidant, 374 retinol activity equivalents (rae), 374 structure of, 370f, c-5f supplements, 274, 392 393 vitamin a precursors, 369, 370f, 372 vitamin e and, 363 see also carotenoids beta cells (pancreas), 113n, 515 beta-cryptoxanthin, 370n, 470n beta oxidation, 222 beverages coffee, 97, 199, 686 fluid balance and, 400 fruit drinks, 53 health drinks for children, 379, 557 health food and malnutrition, 197 healthy choices, 400 kcalories in, 121, 400 liquid diets, 504, 602 soy milk, 53, 65 sports drinks, 121, 487, 495, 507 sugar content, 117 118, 121, 568 teas, 472f, 655, 656, 658t tooth decay and, 119 for weight gain, 308 weight loss and, 297 see also alcohol; caffeine; fruit juices; milk and milk products; soft drinks; water bgh (bovine growth hormone), 686 687 bha, 143n, 684, 684n bht, 143n, 684, 684n bicarbonate, 77, 78, 87, 407, 408, 408f, 413n bifidus factors, 551 552 bile, 78 cholesterol and, 149, 150f components of, 149 emulsification/digestion of fat, 78, 80t, 88, 148f, 149, 150f enterohepatic circulation, 149, 151f vitamin absorption and, 369 bile acids, 122, 149, 150f bile ducts, 73f binders, 409 in-4 index binge drinking, 244 245 binge eating, 274, 275f, 285 binge-eating disorder, 270, 276, 277t bioaccumulation, 675, 675f, 676 bioavailability, 324 of calcium, 418, 419, 420, 420f factors affecting, h-0 of folate, 338, 340 of iron, 444, 444f, 450, 551, 554 of magnesium, 424 oxalates/phytates and, 409 of supplements, 363 of vitamin b12, 603 of vitamins, 324 of zinc, 452 453 bioelectrical impedance, 264f, e-16, e-16t bioelectromagnetic medical applications, 653 biofeedback, 653 biofield therapeutics, 653 bioflavonoids, 346 biological value of proteins, d-1, d-2, d-2t biopharming, 695 biotechnology, 693 697, 694f, 697t see also genetically engineered (ge) foods bioterrorism, 621, 663 biotin, 333 335, 335t, 347f, 356t, c-8f bird flu, 669 birth defects anencephaly, 513 cretinism and iodine deficiency, 456 diabetes and, 527, 528 down syndrome, 340, 530 father s alcohol intake and, 545 fetal alcohol syndrome (fas), 543 545, 543f, 544, 545f folate and, 338, 340, 340f older women and, 530 vitamin a and, 374 websites on, 539 see also neural tube defects birthweight factors affecting, 515 517, 527, 528, 530 low (lbw), 515, 516, 525 526, 530 paternal alcohol intake, 545 prematurity and, 554 bitter orange, 291t black cohosh, 657t bladder cancer, 133, 135, 644t blind experiments, 12 13, 14 blindness, 371, 373, 373f see also vision blood calcium levels, 417f, 418f, 431 iron and, 445, 445f, 446 ph of, 407f plasma, e-17 serum, e-17 white blood cells, 622 623 see also red blood cells blood alcohol levels, 242, 243t blood cholesterol. -see blood lipid profiles; cholesterol (blood) blood circulation. -see vascular system blood clotting aspirin and, 615 in atherosclerosis, 627 fibrin and, 192, 384f ginkgo biloba and, 658 mechanism of, 384f vitamin e and, 382 vitamin k and, 382, 383 384, 384f vitamin k and warfarin, 617 blood glucose levels, 113 117 chromium and, 461 fiber and, 106, 115 116 glycogen and, 112 hyperglycemia, 246t, 637, 638 hypoglycemia, 115, 246t, 641 normal range, 113 regulation of, 112, 113 117, 114f, 190, 461 starches and, 108 sugar and, 120 see also glucagon; glycemic index; insulin blood lipid profiles, 156 157 in children, 587, 588t components of, 156, 630 desirable levels, 156, 588t, 631t diet vs. medications, 589 fish/fish oil and, 159 genetics and, 210 glycemic index and, 115 heart disease risk and, 157, 588t, 628t, 629, 630, 631t inflammation and, 265 266 in obese children, 569 strategies for improving, 157, 162, 173, 633 test method, 151n vegetarian diets and, 65 see also cholesterol (blood); hdl; ldl; triglycerides blood pressure atherosclerosis and, 627 determinants of, 634f heart disease risk, 628t, 631 minerals and, 412, 414, 416, 424 normal/abnormal levels, 528n, 635 regulation of, 401 402, 403f, 412, a-6 in vegetarians, 65 see also hypertension blood sugar. -see blood glucose levels blood transferrin, 443, 443f, 445 blood volume, 401 402, 402f, 403f blueberries, flavonoids in, 472f bmi. -see body mass index (bmi) bmr. -see basal metabolic rate (bmr) body composition, 258 266 overview of, 6, 6f bmr and, 254, 255t, 256 exercise and, 258, 300 301, 478, 599 fat, percentage, 6, 6f, 260, 261f fat distribution, 259, 260 263, 262f, 263f fat vs. muscle, 254, 258, 259, 261f, 397 gender differences, 6f, 260, 261f, 262, 263f, 576 lean body mass, 194, 254, 258, 484 measuring, 258 263, 263f, 264f, e-14f, e-14 to e-15, e-15f, e-16t minerals, 7t, 404t, 409f, b-4, b-4t older adults, 598 599 overweight vs. overfat, 258, 259 skinfold measures, 264f, e-14f water, 6f, 397, 399f during weight loss/gain, 250 body fat. -see fats (body) body image accepting body weight, 259t of athletes, 272 in eating disorders, 272, 276 fashion and bmi, 258 260, 258f sound nutrition and, 5 body mass index (bmi), 259 260, inside back cover calculation of, 259 children, 567, 568f fashion and, 258 260, 258f heart disease risk, 628t mortality and disease, 259, 263 266, 264f protein intake and, 318, 319 weight and height, 288, 289 weight assessment, 260f, 261 body weight. -see weight (body) bolus, 73, 74 bomb calorimeter, 250, 250f bone, powdered, 431 bone density, 431 437 body weight and, 260 breastfeeding and, 535 calcium and, 416, 417, 417f, 418, 418f, 419, 431 437, 523, 535, 577 exercise and, 478, 484 fluoride and, 460 hormones and, 434 435, 434n, a-6 maximizing, 434 measuring, 432 milk and, 577, 578 peak bone mass, 378, 418, 421f, 577 race and, 260 soft drinks and, 578 vitamins and, 377, 378, 384, 434, 436 see also osteoporosis bone fractures milk/calcium and, 419 osteoporosis and, 431, 432 protein and, 436 stress fractures in athletes, 270, 271 underweight and, 264 vitamin a excess, 374 vitamin d and, 379 bone marrow, 445 446, 445f bone mass. -see bone density; osteoporosis bone meal, 431, 436 bones, 431 437 calcium and, 416, 417, 417f, 418, 418f, 419, 431 437, 523, 535, 577 colas and, 422 cortical, 431, 432 as dietary calcium source, 419f, 420 fetal development of, 522 523 growth/remodeling of, 372, 416, 435 436 hormones and, 416, 417, 417f magnesium and, 423 424 minimizing loss, 434 osteoarthritis, 605 silicon and, 462 structure of, 190, 432f trabecular, 431 432, 432f vanadium and, 462 vitamin a and, 372, 374, 436 vitamin c and, 353 vitamin d and, 377, 378, 434, 436, 522 523 see also rickets websites on, 437 see also osteoporosis boron, 462, 504 bottled water, 400, 401, 689 botulism, 118n, 556, 556n, 665t, 666, 671 bovine growth hormone (bgh), 686 687 bovine spongiform encephalopathy, 668n bowel movements, 78, 93 95 see also constipation; diarrhea brain aging and, 606 607, 606t, 607t alcohol and, 242 243, 242f, 243t, 544 blood volume regulation, 403f deficiencies/malnutrition and, 563, 606, e-7 development of, 209, 550, 552 in eating disorders, 272 energy source for, 112, 156, 223, 234 fetal nutrient needs, 520, 532 hunger and, 251, 253, 562, 563 lead toxicity and, 463 nutrient relationships, 606t omega-3 fatty acids and, 155 pcb/mercury and, 676 zinc deficiency and, 453 see also hypothalamus bran, 50, 50f branched-chain amino acids, 203 breads, 50 51 calcium in, 419 in canadian food groups, i-8t enriched/fortified, 50 51, 51f, 450 in exchange lists, g-1t, g-4t fiber in, 51f, 51, 126f folate fortification, 51, 340, 340n, 342f heart disease and, 633 labels, 126f nutrients in, 42f, 50 51, 51f phytates in, 453n in usda food guide, 42f whole grain, 42f, 50, 51f, 126f see also grains breakfast, 574, 577 breakfast cereals, 51 52, 412, 412f, 555 556 breast cancer breastfeeding and, 537 dietary fat and, 160 estrogen and, 266, 643 exercise/weight and, 643 folate and, 341 risk summary, 644t breast disease, fibrocystic, 382 breastfeeding, 532 540 alcohol and, 537 benefits of, 531, 533t, 537, 550 552, 554 caffeine and, 538 cancer risk and, 537 certified lactation consultants, 534 drug use, illicit, 537 duration of, 550, 555 energy needs during, 521f, 534 535 fish consumption and, 531, 676 frequency of, 550 iron needs and, 536 lactation, defined, 533 maternal health and, 536 537 medications and, 537 nutrient needs during, 521f, 534 536, inside front cover physiological process of, 533 smoking and, 537 support for success, 534, 534t websites on, 539 breast milk composition of, 535, 550 551, 550f, 553f environmental contaminants in, 174, 531, 538, 676 foods flavoring, 536 hormones affecting, a-5 preterm, 554 breast milk banks, 552 brown adipose tissue, 286 buffalo meat, 719 buffers, 407, 408f bulimia nervosa, 93, 270, 274 276, 274t, 275f, 275t see also eating disorders butter, 144f butter vs. margarine, 157, 166f, 471 butyric acid, 108n b vitamins, 326 350 overview, 326, 356t coenzymes and, 216, 220, 326, 327, 327f, 347 348, 347f deficiencies, 244, 348 349, 349f, 356t dri, rda and ai, 326 energy metabolism and, 326, 347 348, 347f food sources, 349, 356t functions of, 347 348, 356t heart disease and, 199, 200 interdependence, 346 list of, 10n non-b vitamins, 345 346 toxicities, 349, 356t see also specific b vitamins c cabbage family, 456, 645, 677 caffeine, 503 adolescents intake, 578 athletic activity and, 496, 505 decaffeinated coffee, 686 diuretic effects, 400 in foods/drinks/drugs, h-0 to h-1t iron bioavailability, 538 lactation and, 538 pharmacologically active dose, h-1n pregnancy and, 532 websites on, 581 calcitonin, 191t, 416, 417, 417f, 434n, a-3, a-6 calcium, 416 422 overview of, 422t, 426t absorption of, 409, 417f, 418, 434, 436, a-6 antibiotics and, 616 for athletes, 271 bioavailability, 418, 419, 420, 420f blood clotting and, 384f blood levels, 416, 417f, 418f, a-6 blood pressure and, 416 in bones, 416, 417, 417f, 418f, 431 432, a-6 see also osteoporosis breast milk and, 550, 551 children s/adolescents needs, 418, 577 deficiency, 241, 378, 417 418, 422t food sources, 38, 65, 66 67, 418 421, 419f, 420f functions of, 416 418, 422t hormones and, 417f, 432, 434 436, 434n, a-6 intake recommendations, 418, 420, 422t, 435 436 lead toxicity and, 436, 463, 531 for older adults, 603 osteoporosis and, 200, 361, 411, 421, 433 434, 435 436 pregnancy/lactation, 521f, 523, 524, 535 proteins (dietary) and, 200 storage of, 416, 417, 431 432 supplements, 361, 363, 416, 436 in tooth formation, 416 toxicity, 422t vegetarian diets, 65, 66 67, 67n vitamin d and, 377, 378, 417f, 434, 436, a-6 websites on, 427 women s intakes of, 200 calcium-binding protein, 418 calcium rigor, 417 calcium tetany, 417 calculation, aids to, inside back cover see also measurements calmodulin, 416 calories, 7 see also kcalories (kcal) calorimetry, 250, 250f campylobacter jejuni, 664, 665t canada aspartame, 133n dietitians in, 34 dri and, 16n eating well with canada s food guide, i-1, i-2f to i-7f food and nutrition website, 26 guidelines for healthy eating, 40t labeling website, 61 ma huang, 290n meal planning for healthy eating, i-8t to i-11t milk fortification, 375n, 379n nutrition websites, 33, 61 physical activity guidelines, i-7f supplements, 159n, 202n, 442n canadian council of sports medicine, 500 cancer, 642 646 acrylamide and, 686 alcohol and, 244, 246t, 644t, 646t index in-5 alternative therapies, 656t antioxidants and, 391 392, 645 artificial sweeteners and, 133, 134, 135 body weight and, 266, 643, 646t breastfeeding and, 537 carotenoids and, 372 chlorinated water and, 688 classifications of, 642 delaney clause and, 682 environmental/lifestyle factors, 642 643, 644t, 646t exercise and, 478, 646t fat (dietary) and, 159 160 fiber and, 122 123, 448, 645 folate and, 341 food additives and, 682, 684 free radicals and, 448 gastroesophageal reflux and, 97 genetic factors, 642 h. pylori and, 97 healthy people 2010 goals, j-1t initiators/promoters/antipromoters, 642, 643 645, 643f iron and, 448 lung: smoking and supplements, 580 meat and, 160, 392 obesity and, 266 phytochemicals and, 469 470, 472f, 645, 655 proteins (dietary) and, 200 risk reduction, 644t, 645, 646t saturated fats and, 160, 645 selenium and, 457 skin, 379 380 soy products, 469 470, 472f sugars on cell membranes, 112 trans fats and, 645 vegetable/fruit intake, 65, 372, 391 392, 470, 643, 644t, 645 vegetarian diets and, 65 vitamin intake and, 392, 656t websites on, 648 whole grains and, 645, 646t see also specific types candy. -see sweets capillaries, 82f, 83, 84f capsaicin, 470t carbohydrase, 77, 108 carbohydrate loading, 487, 488 carbohydrates, defined, 101 carbohydrates, unavailable, 108 see also fiber carbohydrates (body). -see blood glucose levels; glucose; glycogen carbohydrates (chemistry), 101 107 elements in, 7t metabolism of, 114f, 115 116, 215t, 219 222, 219f 222f, 233, c-10 to c-11 structure of, 102 107, 102f 107f, c-1 to c-3f types of, 102 107, 107t see also energy metabolism carbohydrates (dietary), 101 129 absorption of, 108 110, 110f available, 108 body s use of, 227t in breast milk, 550, 550f in breast milk vs. formula, 553f in canadian food groups, i-8t to i-9t, i-9t for children, 559 complex, 101, 105 107, 297 cravings for, 120 121 diabetes and, 640 641 dietary guidelines and, 40t digestion of, 77, 79f, 80t, 107 108 energy (kcal) in, 9t in exchange lists, 48, g-1t, g-3t, g-4t in-6 index carbohydrates (dietary), continued for exercise, 485 488, 485t, 486f, 488t, 490, 497 fat made from, 113, 156, 222, 227t, 232, 233 fat metabolism and, 226, 228n in food group plans, 41t, 42f 43f, 44t, 48t glycemic effect, 488 glycemic index, 115 116, 116f, 316, 488 glycogen, effects on, 487 488 glycogen depletion, 319 320 high-impact vs. low-impact, 488 importance of, 227 on labels, 58, 126 127, 126f for older adults, 602 overeating and, 232, 233, 234f as percent of energy intake, 487n protein-sparing action of, 112, 194 recommended intake of, 18, 124 127, 125t, 126f serotonin and, 120 simple, 101 105. see also sugars types of, 102 107, 107t unavailable, 108 in weight control, 101, 113, 120, 233, 296t, 298 for weight loss, 295t, 315, 318 see also diets, high-carbohydrate; diets, low-carbohydrate; starch; sugars; sweets carbon, 7t, 218, b-3 carbonated water, 400 carbon bonds, 102, 102f, 140 142, 145f, b-3 carbon dioxide, 221, 227n, 407, 408f, 483f carbonic acid, 407, 408f carbonic anhydrase, 452n carboxypeptidases, 186f carcinogenesis, 642 carcinogens, 642, 644, 644n, 645, 686 carcinomas, 642 cardiac arrest, 626, 627 cardiac output, 482, 634f cardiac sphincter. -see esophageal sphincter cardiorespiratory conditioning, 482, 483f cardiorespiratory endurance, 480, 482 483 cardiorespiratory fitness, 266, 480t cardiovascular disease (cvd), 157, 587, 626 632 alcohol and, 244, 246t, 336, 632t antioxidants and, 392 arginine and, 199 200 breastfeeding and, 552 b vitamins and, 199, 200 cholesterol (blood), 13f, 152, 157, 392, 587, 628t, 629 cholesterol (dietary), 157 158, 175f, 632t copper deficiency, 458 coronary heart disease (chd), 157, 587, 626, 628 632, 628t, 632t death rates, 24t, 157, 628 in diabetics, 629, 640 early development of, 586 588 exercise and, 478, 489, 629, 632t fats: fish/fish oils, 159, 174, 632t fats: healthy choices, 157, 176t, 633 fats: high-fat diets, 172 177 fats: monounsaturated, 65, 158, 173, 633 fats: omega-3 fatty acids, 158, 159, 174, 632t fats: plant vs. animal, 65, 144f, 157, 199 fats: polyunsaturated, 65, 158, 392 fats: saturated, 157, 158, 173, 175, 175f, 632t fats: trans, 143 144, 157, 632t, 633 fetal development and, 515 fiber and, 106, 122, 123t, 632t folate and, 340 341 genetic factors, 120, 210, 586 glycemic index and, 115 healthy people 2010 goals, j-1t to j-2t high-protein, low-carbohydrate diets, 319 homocysteine and, 199, 340 341 hypertension and, 627, 628t, 629 iron stores and, 448 lifestyle and, 24, 586 589, 628t, 629 630 magnesium and, 424 meat and, 319 mediterranean diet and, 13f, 173, 175, 177, 471 metabolic syndrome and, 630 niacin and, 332 nuts and, 173 174 orange juice and, 13f phytochemicals and, 163, 470t, 471, 472f plant sterols/stanols and, 632t potassium and, 632t proteins (dietary) and, 199 200 risk assessment, 631 risk factors, emerging, 630 risk factors: major, 481, 628 632, 628t risk reduction strategies, 392, 630 632, 632t, 633 selenium deficiency and, 457 smoking/tobacco use, 589, 629, 632t sodium and, 400, 632t soy products and, 65, 472f, 632t statistics on, 589 sugar and, 120, 632t vegetable/fruit intake, 392, 471, 630, 633 vegetarian diets and, 65 vitamin deficiencies and, 336 vitamins and, 13f, 382, 392 websites on, 168 weight/obesity and, 265, 629, 630, 632t whole grains and, 630, 633 see also atherosclerosis; hypertension; strokes careers in nutrition. -see health care professionals carnitine, 346, 352, 364, 503, 504 carotene, c-5f carotenoids, 369 bioavailability of, 375 cancer and, 372, 392 effects of, 470, 470t, 471 food sources of, 375 376, 470t, 472f hypercarotenemia, 377n types of, 370n vision and, 605 as vitamin a precursors, 370f, 375 376 see also beta-carotene carpal tunnel syndrome, 336 carrying capacity, 707 cartilage therapy, 653 case-control studies, 13f casein, 550 catabolism, 215f, 216 see also energy metabolism catalase, 391n catalysts, 76 cataracts, 604 605 cathartics, 270, 274 275 cations, 403, 404t, 405f causation vs. correlation, 15 cck (cholecystokinin), 88, 88t, 149, 251, 252, a-6 cdc (centers for disease control), 499, 664 cell differentiation, 371 cell membranes, a-2 cell structure and, 214f free radicals and, 452 phospholipids in, 145, 146f, 422 selective permeability, 404 405 structure of, 81f, 146f, a-3f sugars and, 112 transport proteins in, 191, 192f cells, a-2 to a-3 in absorptive process, 80 81, 82f adipose cells, 155 156, 155f, 266, 282, 283f, 284, 286 alpha cells (pancreas), 113n beta cells (pancreas), 113n, 515 composition of, b-4, b-4f electrolytes and, 403, 404 405, 405f epithelial, 371 fluids associated with, 399f of immune system, 622 623 metabolism within, 214, 214f red blood cells, 447f. -see red blood cells structure of, 214f, a-2 to a-3, a-3f vitamin a and differentiation of, 371 white blood cells, 622 623 cellulite, 291 cellulose, 106, 106n, 107f, 122, c-2 centers for disease control (cdc), 499, 664 central nervous system, a-7 to a-8, a-8f see also brain; nerves/nervous system central obesity, 262 263, 262f, 263f alcohol and, 243 disease/mortality, 265, 630 exercise and, 301 302 smoking and, 262 cereals. -see breads; grains cereals, breakfast, 51 52, 412, 412f, 555 556 cerebral thrombosis, 627 cerebrovascular accident (cva), 626 certification (pesticide inspections), 682 certified nutritionists, 32 ceruloplasmin, 458n cervical cancer, 644t cesarean section, 516, 522, 522n, 529 530 chaff, 50f chamomile, 657t chaparral, 657t chd risk equivalents, 626, 629, 631 cheese, 47, 111, 126 see also milk and milk products cheilosis, 330n, 349f chelates, 451 chelation therapy, 653 chemistry, b-1 to c-17 acids/bases. -see ph of amino acids, 181 183, 182f, 182t atoms, properties of, 102, 102f, b-1 to b-3, b-2t basic concepts of, b-1 to b-8 biochemical structures/pathways, c-1 to c-17 bonds, 140 142, 145f, b-3, b-3 to b-4, b-4f of carbohydrates, 101 107. see also carbohydrates (chemistry) carbon backbones, 218 chemical reactions overview, b-6 to b-8 composition of foods, 6, 7t, 9 electrolytes, 402 404, 404f, 404t, 405f elemental composition of body, 409f, b-4t elements, table of, b-2t enzymes/coenzymes, 76 78, 327f of fats, 139 144. see also fats (chemistry) free radicals. -see free radicals ion formation, b-5, b-5 to b-6 minerals, 408 of nutrients, 5 11, 7t oxidation-reduction reactions, b-7f, b-7 to b-8 of proteins, 181 185. see also proteins (chemistry) vitamins, c-5 to c-9f see also energy metabolism; laboratory tests; metabolism chewing, 599 600 chicken. -see poultry child, julia, 177 children, 558 575 overview of nutrient needs, 559 562, 562f aspartame, 135 behavior of, 120, 562, 563, 564 565 body mass index, 567, 568f body shape of, 559f bone mass, 435 436 calcium, 418, 435 436 choking in, 92, 557, 572 cholesterol levels, 587, 588t chronic diseases, early development of, 586 589, 588t deficiencies and health beverages, 379 diabetes and obesity, 115, 569, 586 dietary guidelines for, 40t energy needs, 558 559, 560, 562t exercise for, 567, 569, 571 fat cell development in, 282 fats (dietary), 155, 560, 588 fish consumption, 174, 676 food allergy/intolerance, 565 567 growth assessment, e-6 to e-7, e-11f to e-13f healthy people 2010 goals, j-2t hypertension in, 587 588 infectious diseases and, 372 373, 453 iodine deficiency in, 456 iron deficiency, 446, 447 iron-deficiency anemia, 560, 563 iron toxicity, 361 362, 448 lead toxicity, 463, 463t, 564 learning and nutrition, 562, 563 malnutrition in, 197 199, 562 564, 563t, 705, 707, e-7 mealtime guidelines, 571 573 milk for, 379, 418 419, 554, 557 overweight, 115, 281, 558, 567 571, 567f, 568f, 586, e-7 pesticides and, 678, 681 protein-energy malnutrition (pem), 196 199, 197t, 198f, 199f protein needs, 560 school nutrition programs, 573 575 supplement overdoses, 361 362, 448 supplements for, 560 toddlers, 557 558, 571t vegetable/fruit intake, 561 562, 569, 571, 573t vegetarian diets and, 559 vitamin a and, 372 373 vitamin d and, 37f, 378. see also rickets websites on, 580 581 of women with anorexia nervosa, 273 zinc deficiency, 453 see also adolescence; infants china, 457 chiropractic, 653 chitosan, 291t chloride, 413 414, 414t, 426t deficiency and toxicity, 413 414, 414t functions of, 413, 414t intake recommendations, 413, 414t losses of, 406, 413 chlorine, atomic structure of, b-5 chlorophyll, 376 chocolate, 120 121, 472f choking in infants/children, 92, 557, 572 prevention of, 92, 93f, 97t vs. normal swallowing, 92f cholecalciferol, 377, 379n, c-8f see also vitamin d cholecystokinin (cck), 88, 88t, 149, 251, 252, a-6 cholesterol, 146, 147f cholesterol, endogenous vs. exogenous, 146 cholesterol (blood) in childhood, 587, 588t dietary cholesterol and, 157 diet vs. medications, 589, 632 fiber and, 106, 122 good vs. bad, 152 heart disease and, 13f, 152, 157, 587, 628t, 629, 631 levels. -see blood lipid profiles lipoprotein composition, 151 152, 153f margarine and, 157, 164n, 471, 472 mycoprotein and, 471 niacin and, 332 saturated fats and, 157, 158, 175, 175f soy products and, 65, 162, 471, 472f synthesis of, 122, 147, 162 trans-fatty acids and, 157 weight loss and, 294 see also hdl; ldl; vldl cholesterol (body), functions of, 147, 147f, 149 cholesterol (dietary) blood cholesterol and, 157 daily value for, 147 exogenous, 146 food sources, 146, 157, 158f heart disease and, 157 158, 173, 175f on labels, 58, 58n reducing, 157 158 scavenger pathway, 152 u.s. intake of, 157f, 161 websites on, 168 choline, 145, 146f, 345, 345t, 346, 607 chondroitin, 606 chromium, 461 462, 462t, 464t chromium picolinate, 461, 503, 504 chromosomes, 207, 208, 208f, a-2, a-3f see also dna; genetics/genes chronic diseases, 3, 24, 624 660 overview of risk factors, 24 25, 25t, 624 625, 625f alcohol and, 244, 246t antioxidants and, 392 body fat and, 262, 263f, 265 266 calcium and, 414 diet recommendations, 632t, 633, 646 647, 647f diet recommendations: fat, 159 160, 172 177 early development of, 586 589 energy intake restriction and, 597 exercise and. -see physical activity, benefits of fetal development and, 515 folate and, 340 341 genetics and, 210, 625, 625f, 647 lifestyle and, 586 589, 625, 625f, 629 630 mediterranean diet and, 13f, 173, 177, 471 obesity and, 115, 262, 263f, 289, 586, 625f, 646 obesity as, 292 proteins (dietary) and, 199 200, 319 supplements and, 361 vegetarian diets and, 65, 67 websites on, 648 weight loss and, 294 see also cancer; cardiovascular disease (cvd); diabetes; hypertension chronic pem, 197 chronological age, 595 chylomicrons, 83, 149, 151, 152f, 153f chyme, 74, 74, 75, 87 chymotrypsin, in protein digestion, 186f ciguatera poisoning, 670n ciprofloxacin, 616 circulatory systems. -see lymphatic system; vascular system cirrhosis, 239, 241 cis-fatty acids, 143, 145f clay eating. -see pica climate change, 709 clinically severe obesity, 292 clinical trials, 13f, 14t clostridium perfringens, 665t coa. -see coenzyme a (coa) cobalamin. -see vitamin b12 cobalt, 462, 462f cocaine, 579 coconut oil, 142, 144f, 157, 175 coenzyme a (coa), 218 index in-7 formation of, 347f, 348 function of, 221f, 334, 347f structure of, c-7f coenzyme q10 (ubiquinone), 346, 504 coenzymes, 216 b vitamin deficiencies and, 326 b vitamins and, 216, 220, 326, 328, 330f, 336 folate and, 338 in glucose metabolism, 219f 222f mechanism of action, 327f pantothenic acid and, c-7f pyridoxal phosphate (plp), 336 vitamin b6 and, c-7f vitamins and tca cycle, 228f, 328, 330f, 347f, 348 vitamins/structures of, c-5 to c-9f cofactors, 216 coffee, 97, 199, 686 cognitive function. -see brain; intelligence cohort studies, 13f cola beverages, 39, 422, h-1t colds, 12 15, 352, 455, 478 colitis, 94 collagen, 190, 192, 351 352 collagenase, 186f colon/colorectal cancer alcohol and, 244 fiber and, 122 123 meat and, 644 risk summary, 644t vegetarian diet and, 65 colonic irrigation, 94, 95 colon (large intestine), 72, 73f anatomy of, 74, 78f bacteria in. -see intestinal bacteria carbohydrate/fiber digestion in, 106, 108, 109f diverticular disease, 94, 94f, 95, 122 fiber and, 78, 79f, 122 function of, 73f, 74, 78f, 79f vegetarian diets and, 65 colostrum, 551 combining foods myth, 81 82 comfrey, 657t complementary and alternative medicine, 652 659 herbal remedies, 654f, 655 658, 656t 658t for hyperactivity, 564 nutrition-related, 654 658 risk-benefit relationships, 652, 655f, 656 658, 656t 658t websites on, 659 complementary proteins, 195 196, 196f complex carbohydrates. -see under carbohydrates (dietary) composition of foods, h-0 to h-77t see also chemistry composition of the body. -see body composition compound, defined, b-1 conception, 510 fertility/infertility, 264, 526 see also fertility/infertility condensation, 104, 104f, 143f conditionally essential nutrients, 156, 183, 345 conditioning, 480 cones (of retina), 371f congregate meals programs, 609 constipation, 94 fiber and, 95, 106, 122 iron supplements and, 451 in older adults, 602 during pregnancy, 524t, 525 prevention of, 95, 97t treatment of, 95 consumers, 663 698 alternative medicine, 657 658 energy and food production, 717 720, 719f in-8 index consumers, continued costs environmental contaminants, 676 677 food additives, 682 687 foodborne illnesses, 664 673, 665t gm food concerns, 695 696, 697t pesticides, 567, 678 681 water, 687 689 websites for, 33, 34, 690 691 weight-loss bill of rights, 290t see also grocery shopping contaminants, 674 dietary variety and, 39 in seafood, 159, 174, 531 in supplements, 203, 436 in water, 401, 553, 565 see also environmental contaminants; foodborne illnesses; lead contamination, cross-, 566, 667, 670 contamination iron, 450 451 continuing survey of food intakes by individuals (csfii), 22n contraceptives, 341, 537 control groups, 12, 14 convenience and food choices, 4, 567 conventional medicine, 652 cooking/food preparation acrylamide and, 644 645, 685 686 for children, 571 573 environmental considerations, 712 fat recommendations, 173 177 foodborne illnesses, preventing, 665t, 667 671, 669f, 671t grilled meats and cancer risk, 644 645, 644n iron from cookware, 450 451 lead poisoning, preventing, 565 low-fat tips, 53, 161 167 microwave, 344, 686 minerals, 10, 408, 420, 450 451 niacin, 332 nutrient loss, minimizing, 10, 324t, 674 for older adults, 600, 608, 609 610 pesticide residues, minimizing, 680 salt, reducing, 411 thiamin, 324, 328 trans-fats, 159 vitamin b6, 336 vitamin b12, 344 345 vitamin c, 354 vitamin e, 383 vitamins and, 10, 324t websites on, 427, 713 see also diet planning; grocery shopping; processed foods cool-down, 481 copper, 458 459, 464t overview of, 459t absorption of, and zinc, 453, 458 deficiency, 458, 459t functions of, 458, 458n, 459t intake recommendations, 459, 459t toxicity, 459, 459t cori cycle, 220f, 221, 487 corn and niacin, 332 corn breeding, 693 cornea, 371 corn syrup, 118, 556 coronary arteries, 626 coronary heart disease (chd), 157, 587, 626, 628 632, 628t, 632t see also atherosclerosis; cardiovascular disease (cvd) coronary thrombosis, 627 correlation (research), 14, 15 correspondence schools, 32, 33 cortical bone, 431, 432 corticotropin-releasing hormone (crh), a-3, a-4, a-5 breastfeeding vs. formula, 533t food choices and, 4 of functional foods, 472 low-budget meals, 610, 704 of physical inactivity, 478 of pregnancy in adolescents, 529 of supplements, 364 of weight loss treatments, 288 see also food assistance programs coupled reactions, 216, 217f covert, defined, 22 cp (creatine phosphate), 484 485, 485t cravings for nonfood substances, 447, 525 during pregnancy, 525 for sugar/carbohydrates, 120 121 c-reactive protein, 627 creatine, 485, 503, 504 505 creatine phosphate (cp), 484 485, 485t credentials, fake, 33 cretinism, 456 creutzfeldt-jakob disease, 668n crib death. -see sudden infant death syndrome (sids) critical periods (fetal development), 512 515, 512f cross-contamination, 566, 667, 670 cross-sectional studies, 13f cruciferous vegetables, 456, 645, 677 cryptosporidiosis, 665t crypts, 80, 82f curcumin, 470t cutins, 106n cyanocobalamin. -see vitamin b12 cyclamate, 132, 133t, 135 cyclosporiasis, 665t cysteine, 184f, 425 cytochrome c oxidase, 458n cytochromes, 443n cytokines, 622 cytoplasm, 214f, a-2, a-3f cytosol, a-2 d daidzein, 470t daily values (dv), 55 calculating personal values, 57, 165 carbohydrate recommendations, 124 fat recommendations, 160 161, 165 167 for food labels, inside back cover on labels of foods, 54f, 55 57, 56t, 166f proteins (dietary), 196, 197n dairy products. -see milk and milk products dash eating plan, 411, 416, 635t, 636, 636t ddt, in breast milk, 538 deamination, 225, 226f death from aids, 624t alcohol and, 25t, 242, 244, 245, 624f bmi and, 264f, 265 from cancer, 24t causes of, in u.s., 24, 24t, 25t, 624f from choking, 92 from chronic diseases, 624f from dehydration, 398, 398t from diabetes, 24t, 637 from diarrhea, 707 from drugs, illicit, 25t, 290, 579 from eating disorders, 273, 274 from foodborne illnesses, 664, 665t, 666, 670 from heart disease, 24t, 157, 628 from heat stroke, 494 from infant formulas in developing countries, 536 537 from infections, 24t, 199 iron supplements and, 361 362, 448 from malnutrition, 199, 701, 707 obesity and, 263, 264f, 265 during pregnancy, 529, 530 from scurvy, 350 from sids, 531 smoking and, 25, 25t from strokes, 24t, 628 vitamin a deficiency and, 562 from water intoxication, 398 defecate/defecation, 94, 95 see also constipation; diarrhea; feces deficiencies, 17, 22 alcohol and, 241, 243 244, 327, 336, 338 assessment of. -see nutrition assessment behavior and, 447, 562, 563 brain function and, 606 causes of, 348 covert, 22 development of, 19, 22, 22f dietary adequacy and, 37 disease, distinguishing from, 348 349, 350 exercise and, 478, 492 immune system and, 599 in infants, 557 as interrelated, 346, 348 laboratory tests and, 21 22 lactose intolerance and, 111 minerals, summary of, 426t obesity surgery and, 293 in older adults, 599, 606 overt, 22 in preterm infants, 554 primary, 22 protein-energy malnutrition (pem), 196 199, 197t, 198f, 199f proteins (dietary), 196, 241 rice milk/drinks, 197 role of dri/rda/ai, 17, 18f secondary, 22 subclinical, 22, 360 361, e-17 sugar intake and, 117 119 supplements for correcting, 360 symptoms of, 20, 22, 348 349, 350. see also under specific nutrients see also malnutrition; nutrition assessment; specific nutrients degenerative arthritis, 605 dehydration, 398 alcohol use and, 243 athletes making weight, 272 chloride and, 413 414 exercise and, 493 496, 494t high-protein diets, 226 in infants, 549 in older adults, 601 oral rehydration therapy (ort), 406, 707 rehydration, 406, 494 495, 494t salt tablets and, 412, 495 signs/effects of, 398, 398t, 400, 493, 494 vomiting and, 93 dehydroepiandrosterone (dhea), 503, 506 delaney clause, 682 dementia, senile, 606, 607t denaturation, 184 185 dental caries, 119, 119f children and, 572 fluoride and, 460 461 infant bottle feeding, 553, 554f lead and, 463 sugar and, 119 sugar replacers and, 136 websites, 127 see also teeth dental plaque, 119 deoxyadenosylcobalamin, 342 deoxyribonucleic acid. -see dna deoxythymidine kinase, 452n depression, 155, 275, 478, 600, 607, 654f dermatitis of pellagra, 332f designer foods. -see functional foods development, sustainable, 708, 711 dexa (dual energy x-ray absorptiometry, 264f, 432, e-16t dextrins, 108 dextrose, 102, 118 see also glucose dha (docosahexaenoic acid), 154, 159n, 159t, 174, 550 dhea (dehydroepiandrosterone), 503, 506 dhf (dihydrofolate), 338 diabetes, 115, 637 641 complications of, 639 640, 639f development of, 637 638 exercise and, 478, 638, 641 fetal development and, 515, 527 528 fiber and carbohydrates, 106, 123t glycemic index and, 115 healthy people 2010 goals, j-1t heart disease risk, 629, 640 hyperglycemia and, 637 hypoglycemia and, 115 laboratory tests for, 354 nutrient-gene interactions, 515 obesity and, 115, 265, 289, 569, 586, 638 in pregnancy (gestational), 528 race/ethnicity and, 638 statistics on, 586, 637f websites on, 127, 539, 648 weight loss and, 265, 641 diabetes type 1, 115, 637 overview of, 638, 638t causes of, 115, 638 diet and, 641 lactation and, 537 metabolic consequences of, 639f pregnancy and, 527 vs. type 2, 638t diabetes type 2, 115, 637 overview of, 638, 638t causes of, 115, 638 in children, 569 fiber and carbohydrates, 122 insulin resistance and, 638 metabolic consequences of, 639f obesity and, 289, 569, 586 vs. type 1, 638t weight loss/exercise, 641 diarrhea, 94 cause/treatment, 93 94, 665n deaths from, 707 dysentery, 198 electrolyte balance and, 93, 406, 413 in infants, 552, 556 malnutrition and, 198, 199 oral rehydration therapy, 707 prevention of, 97t travelers , 672, 673 dietary folate equivalents (dfe), 338, 339 dietary guidelines for americans, 39-41, 40t alcohol, 45, 238 breastfeeding, 535 children/teens, 554, 557, 559, 560, 570, 576, 577 chronic disease reduction, 636, 646, 647, 647t dental caries, 119 eating patterns, 41 exercise/physical activity, 300, 305, 306, 479, 483, 519, 535, 559, 576, 595, 647 fat intake, 45, 160 161, 162, 164, 560 fiber intake, 124 folate intake, 510, 514 foodborne illnesses, 531, 557, 610, 667, 668, 671 fruits/vegetables, 52, 53, 124 iron intake, 449, 510 key recommendations, 40t milk, 53, 554, 577 nutrient-dense foods, 45 older adults, 597, 605, 612 overweight children, 570 potassium-rich foods, 412, 636 pregnancy, 510, 514, 516, 519, 531 salt/sodium intake, 45, 411, 412, 636 sugar intake, 45, 121 vitamin b12, 603 vitamin d, 380, 603 vs. mypyramid and labels, 60t websites on, 40, 61 weight and health, 250, 294, 300, 305, 306, 570 whole grains, 51, 124, 559 dietary reference intakes. -see dri (dietary reference intakes) dietary supplement health and education act of 1994, 365, 442 dieter s tea, 290 dietetic technician, registered (dtr), 32 dietetic technicians, 32 diet history, 20 21, 287, e-2t, e-3 to e-5 dietitians, 32 duties of, 32 education of, 32, 33, 33n hunger activism, 711 public health, 32 registered, 19, 32 websites for finding, 34 dietitians of canada, 33, 34 diet planning, 37 67 blood glucose and balanced meals, 114 116 canadian food group system, i-1, i-2f to i-7f, i-8t to i-11t carbohydrate intake, 121, 124 127, 125t, 126f, 497 for cardiovascular health, 632t, 633 for children, 557f, 558 562, 561f, 570, 571 573, 571t, 573t, 588 589 environmental concerns, 712 evaluating foods, 329 exchange lists, 47 48, g-3t to g-11t for exercise, 496 499, 498f fat intake and, 161 167, 172 177 food group plans, 41 53, 42f 43f, 44t, 48t, g-3t, g-3 to g-4 food pyramids, 47, 47f, 65 66, 66f functional foods/phytochemicals, 471 glycemic index and, 115 116 grocery shopping and, 48 53, 608, 704 for infants, 555 557, 555t, 557f during lactation, 534 536 low-cost meals, 704 for obesity. -see obesity treatment for older adults, 600, 607 611 during pregnancy, 519 525, 521f, 522f, 524t principles of, 37 39, 60t protein intake, 66, 199 203, 497 sample menus, 48, 48t, 49f, 498f for single people, 609 610 sugar guidelines, 121 for toddlers, 556 variety, importance of, 67, 89, 329 vegetarian, 44, 46, 64 68, 66f websites on, 61 for weight gain, 307 308 for weight loss, 295 298, 295t, 296f, 299t see also diet therapy diets, 3 dangers of, 289 290, 291t dash eating plan, 411, 416, 635t, 636, 636t fad diets, 290, 315 321, 316t, 317t, 320t hypoglycemia and, 115 kcalories and. -see diets, low-kcalorie ketogenic, 113, 156, 235, 319 320, 320t for lactose intolerance, 111 macrobiotic, 64, 67, 653, 656t index in-9 during pregnancy, 532 tyramine-controlled, 617, 618t see also diet therapy; mediterranean diet; obesity treatment; vegetarian diets; weight loss diets, carbohydrate-modified, 317t diets, high-carbohydrate for athletes, 486, 486f, 487, 488, 497, 498f, 499 glycogen and, 486, 487, 488 heart disease and, 122 protein use and, 490 weight management and, 123 diets, high-carbohydrate, low-fat, 317t diets, high-fat, 13f, 39, 172 177, 488 489 diets, high-fiber, 122 124, 448 diets, high-protein cancer and, 200 chronic disease and, 199 200, 319 dehydration and, 226 effectiveness claims, 316t heart disease and, 319 kcalories in, 200, 318 kidney disease and, 200 osteoporosis and, 200 risks/benefits, 200, 317t thermic effect of, 256, 318 diets, high-protein, low-carbohydrate, 317t, 318, 319 diets, low-carbohydrate energy metabolism and, 227 fat vs. lean loss, 319, 320 glycogen and, 319 320 health effect of, 319 320, 320t myths of, 316t, 318 during pregnancy, 532 protein use and, 490 saturated fats and, 318 319 side effects of, 317t, 320t diets, low-fat for children, 560 diet planning for, 161 167, 162f, 166f fatty acid deficiencies and, 155 guidelines, 172 ldl and, 210 meats in, 53, 162, 163 satiating hormones and, 286 for weight loss, 298 weight loss claims, 316t, 317t diets, low-kcalorie, 235, 295 296, 295t, 296f, 361 see also fasting diets, metabolic type, 317t diets, weight-loss, 315 321, 316t, 317t, 320t diet therapy for constipation, 95 for diabetes, 115, 640 641 for eating disorders, 273, 275 276, 275t, 277t for heart disease, 632t, 633 for hypertension, 410 411, 416, 635t, 636, 636t for irritable bowel syndrome, 94 for kidney disease, 200 for pku, 133 134, 209 see also obesity treatment differentiation (cell), 371 diffusion, facilitated, 81f, 108 diffusion, simple, 81f digestibility of protein, 195 digestion, 71 80 overview of, 71 72 of carbohydrates, 77, 79f, 107 108, 109f of fats, 79f, 147 149, 148f, 151f of fiber by intestinal flora, 78, 79f, 106, 108, 108n, 109f hormones and, 87, 149, 151, a-6 to a-7 in intestines, 73f, 74, 75f, 77, 82f, 87 88, 148f, 149 in mouth, 72 73, 74, 76f, 147 148, 148f in-10 index digestion, continued muscles involved in, 74 76, 75f, 76f nervous system and, 87 88 organs involved in, 72 76, 73f, 79f of protein, 77, 79f, 185, 186f secretions of, 76 78, 76f, 77f, 80t, 87 88 in stomach, 73f, 74, 75, 75f, 148 149, 148f vitamin a deficiency and, 373 websites on, 90, 98 see also absorption; digestive system; gi (gastrointestinal) tract digestive enzymes, 76 78, 77 carbohydrates, 77, 108, 109f, 110 fats. -see lipases lecithinase, 145 protein, 185, 186f in saliva, 76f, 77 see also pancreatic enzymes digestive juices. -see gastric juices; pancreatic juice digestive system, 72, 73f see also digestion; gi (gastrointestinal) tract diglycerides, 147 digoxin, 655f, 657 dihydrofolate (dhf), 338 dihydroxyphenyl isatin, 95n diogenes project, 319 dioxins, 538, 686 dipeptidases, 185, 186f dipeptides, 183, 183f direct calorimetry, 250 disaccharides, 103 chemistry of, 103 105, 104f digestion/absorption of, 108, 109f, 110 111 structure of, 104f, c-1 see also lactose intolerance discretionary kcalorie allowance, 45 energy intake and, 41t, 45f exercise and, 300f fats and, 45, 161 in food group plans, 48t sugar and, 121 disease chronic. -see chronic diseases deficiencies/malnutrition vs., 20, 348 349, 350 exercise and. -see physical activity, benefits of free radicals and, 390 392 genetic. -see genetic disorders genetic engineering and, 696 infectious. -see infections/infectious disease iron overload and, 448 lifestyle and. -see lifestyle choices obesity/overweight and, 115, 265 266, 288 289, 569, 586, 587, 605, 646 risk/prevention overview, 24 25, 24t, 25t, 624 625, 625f smoking and. -see smoking/tobacco use strategies for health, 646 647, 647f underweight and, 264 265 vegetarian diets and, 65, 175 see also specific diseases disordered eating, 270 272 dissociate, defined, 403 distance education and training council, 34 distilled liquor, 238, 239, 244t distilled water, 400 disulfide bridges, 184f dithiothiones, 470n diuretics alcohol, caffeine and water balance, 400, 496 caffeine content of, h-1t hypertension and, 636 637 potassium and, 636 637 diverticula, 94, 95, 95f, 122 diverticulitis, 94, 95 diverticulosis, 94, 95 dna (deoxyribonucleic acid), 207 antioxidants and cancer, 392 chromosomes, 207, 208, 208f, a-2, a-3f folate and, 338, 339f, 341 free radicals and, 391f, 392 fruits and vegetables, 391 392 human genome project, 207 nitrogen in, 193n in nucleus, 208, 208f, 214f phosphorus and, 422 protein synthesis and, 187, 188f, 490 vitamin b12 and, 343, 344 see also genetics/genes; genomics, nutritional dna polymerase, 452n docosahexaenoic acid (dha), 154, 159t, 174, 550 dolomite, 431, 436 double-blind experiment, 13 14, 14 dowager s hump, 433f down syndrome, 340, 530 dri (dietary reference intakes), 16 20, inside front cover for assessing dietary intake, 21f component categories, 16 18, 19 for exercise, 288 for fats, 160 161, 172 high doses of nutrients and, 18f, 325 326 international recommendations, 19 nutritional genomics and, 16 for older adults, 601 purpose/uses of, 16, 18 19 reference adults used, 18 safe vs. toxic nutrient intakes, 18, 18f source of, 16n sugars, 121 websites, 26 drink, defined, 238, 239 driving, alcohol and, 243t, 245 drug, 239 drug history, 20, e-2t, e-3 drug-nutrient interactions. -see nutrient-drug interactions drugs, actions of, 615 drugs, therapeutic. -see medications drug use/abuse adolescents and, 579 alcohol and, 238 lactation and, 537 nutrition problems and, 579 pregnancy and, 530 websites on, 247 see also alcohol abuse dtr (dietetic technician registered), 32 dual energy x-ray absorptiometry, 264f, 432, e-16t duodenum, 72, 73f, 74, 77 duration (of exercise), defined, 480 dv. -see daily values (dv) dwarfism, 453f dysentery, 198 dysmetabolic syndrome, 630 dysphagia, 599 e e. coli infection, 665t, 666 ear (estimated average requirement), 16 17, 17f, 18f, 19, 21f eating behaviors, 302 303 eating disorders, 270 277 anorexia nervosa, 251 252, 270, 272 274, 273t, 307 in athletes, 270 271, 271f, 272 binge eating, 270, 274, 275f, 276, 277t bulimia nervosa, 93, 270, 274 276, 274t, 275f, 275t healthy people 2010 goals, j-2t preventing, 272, 272t risk factors for, 271 society s role in, 276 unspecified, 270, 276, 277t websites on, 277 eat right 4 your type diet, 317t echinacea, 656 657, 657t, 658t eclampsia, 528 529 economic factors. -see costs; socioeconomic status ecstasy, 579 edema, 191 beriberi and, 327, 328f causes of, 191 malnutrition and, 198, 199f pregnancy/preeclampsia, 528 education in alternative medicine, 652 of consumers, 60 correspondence schools, 32, 33 fake credentials, 33 of health care professionals, 31, 33, 33n healthy people 2010 goals, j-1t hunger activism, 711 hungry children and, 562, 563 lead contamination and, 564 of nutrition professionals, 31, 32, 33, 33n population growth and, 709 school nutrition and learning, 562, 573 575 websites on, 34 eer (estimated energy requirement), 18, 257, f-2t, inside front cover eggs avidin in, 334 cholesterol in, 158 enriched with omega-3 fatty acids, 158, 159 recommended intake of, 158 as reference protein, 195 safe handling of, 671 eicosanoids, 154 155, 627 eicosapentaenoic acid (epa), 154, 159n, 159t, 174 elastase, 186f eldercare locator, 609n elderly people. -see aging (older adults) electrolytes, 403 for athletes, 271 272, 494 495, 495 balance/imbalance, 93, 402 406, 404f, 404t, 405f chemistry of, 402 406, 404f, 404t, 405f chloride, 404t, 406, 413 414 in eating disorders, 275 minerals, 404t potassium, 403, 404t, 406, 414 415 replacing losses, 406 sodium, 403, 404t, 406, 410 413 in sports drinks, 495 see also fluid balance electrolyte solutions, 403 405 electrons, b-1 to b-3, b-2t electron transport chain (etc), 218 alcohol and, 241 atp synthesis, 229f, 231f b vitamins and, 347f cytochromes, 443n functions of, 220, 222, 229 iron in, 443 reactions of, c-14f, c-14 to c-15, c-15t elements, 408, b-1, b-2t, b-3 ellagic acid, 470n, 472f elvjhem, conrad, 332n embolism, 626, 627 embolus, 626 embryo, 511f, 512, 512f emergency shelters, 704 emerging infections program (eip), 666n emerging risk factors, 630 emetics, 270, 274 275 emotions, food choices and, 4 5 see also psychological problems empty-kcalorie foods, 39, 298 see also nutrient density ems (eosinophilia myalgia syndrome), 203 emulsification bile acids and, 78, 149, 150f fat digestion and, 78, 88, 148f, 149, 150f phospholipids and, 145 emulsifiers, 78, 685 endocrine glands, 78 see also hormones endocrine system, a-3 to a-5, a-4f endocrinology, a-3 endogenous protein, 193 endopeptidases, 185 endoplasmic reticulum, a-2, a-3f endosperm, 50f endurance, muscle, 480, 480, 481, 484 enemas, 94, 95 energy, 6, 7 10, b-1 amino acids and, 226f brain and glucose, 234 carbohydrates, simple, 101 105 deficiency vs. excess, 20 in exchange list portions, 47 48 from fiber, 108, 108n, 109 from glucose vs. fat, 101 kcalories (kcal) as measure of, 7 9 ketone bodies, 113 on labels, 56 57 photosynthesis, 213 protein intake vs., 201 requirements. -see kcalories (kcal) needs from short-chain fatty acids, 108, 108n, 109f usda food guide servings, 41, 41t, 44t, 49f see also energy metabolism; kcalories (kcal); metabolism energy balance, 249 257 overview of, 249 250 appetite and, 251 253, 252f, 253f components of energy expenditure, 253 256, 254f, 255t estimating energy requirements, 256 257 leptin and ghrelin, 284 286 energy density, 8 9 comparing foods, 9f obesity and, 287, 569 for weight gain, 308 for weight loss, 296 297, 297f, 298 energy metabolism, 213 236 overview of, 214 218 acetyl coa. -see acetyl coa aerobic vs. anaerobic, 220, 485, 485t, 490 alcohol and, c-15, c-16f amino acids, 194, 224 226, 225f, 226f, 231f, 347f, c-11, c-12f atp. -see atp (adenosine triphosphate) basal metabolism and, 254 256, 254f, 255t b vitamins and, 326, 327, 328, 333 334, 335, 347 348, 347f carbohydrates, 114f, 115 116, 219 222, c-10 to c-11, c-14f, c-15t central pathways, 231f copper and, 458n electron transport chain. -see electron transport chain (etc) energy balance and, 230, 232 236 exercise: atp and cp, 484 485, 485t exercise: fat, 485t, 489 exercise: gender and eer, 257 exercise: glucose/glycogen, 485 488, 485t, 486f exercise: protein, 486f, 490 491, 491t exercise: specific activities, 255t, f-1 to f-6t exercise: weight loss, 300 fasting, effects of, 233 236, 234f, 235f fats. -see fat metabolism; oxidation (of fats) feasting, effects of, 232 233 final steps of, 227 230 glucose, 112, 114f, 115 116, 219 222, 219f 222f, 228n, 231f glycerol, 222, 224f, c-10 hormonal regulation of, a-5 to a-6 iron-deficiency anemia, 447 of lean tissue, 254 magnesium and, 424 metabolic water, 398 399, 399t nutrient use summary, 226, 227t oxidation-reduction reactions, b-7f, b-7 to b-8 phosphorus and, 422 proteins, 192, 201, 490, 491t pyruvate. -see pyruvate tca cycle. -see tca (krebs) cycle thyroid hormones and, 455 uncoupling proteins, 286 vitamins and, 347 348, 347f weight changes and, 283, 300, 305 white vs. brown adipose tissue, 286 see also kcalories (kcal) energy restriction (and longevity), 596 597 energy-yielding nutrients, 7 11, 9t, 18, 217 218 see also specific nutrients enriched (foods), 50 52 see also fortified (enriched) foods enterogastrones, 87 enterohepatic circulation of bile, 149, 151f of folate, 338 of vitamin b12, 343 enterokinase, 186n enteropancreatic circulation, 452, 453f enteropeptidase, 186f environmental consciousness ecological footprint, 719, 719f energy and food production, 717 720, 719f food choices and, 4 5, 711 713 genetic engineering, 695 696, 697t global vs. local food, 719 720 websites on, 697, 720 environmental contaminants, 674 677 agriculture and, 716 717 bioaccumulation, 675f, 676 cancer risk and, 642 643, 644t dioxins, 538, 686 heavy metals, 463. see also specific metals hunger and overpopulation, 708f, 709 710 infant formulas and, 536 manganese, 459 460 mercury, 159, 174, 531, 675 676, 675f, 676 677 pbb and pcb, 676 pregnancy and, 531 see also lead environmental protection agency (epa), 664, 676, 678, 680, 688 enzymes, 190 alcohol/drug metabolism, 240, 241, 242 in breast milk, 552 carbohydrate digestion, 77, 108, 109f, 110 coenzymes and, 216, 327f copper-requiring, 458, 458n digestion of, 77, 185 fat digestion. -see lipases free radicals and, 391, 391n functions of, 190, 191t, 216, 216 gastric, 77, 149 of intestinal cells, 77, 81 lactose intolerance and, 110 111 lecithinase, 145 mechanism of action, 190f metalloenzymes, 452, 452n, 462 pancreatic. -see pancreatic enzymes protein digestion and, 77, 185, 186f renin, 401 index in-11 salivary, 76f, 77 in supplements, 364 zinc-requiring, 452 see also coenzymes eosinophilia myalgia syndrome (ems), 203 epa. -see eicosapentaenoic acid; environmental protection agency ephedra, 290, 657t, 658 ephedrine, 290, 291t epidemic, 282, 283 epidemiological studies, 13f, 14t epigenetics, 189, 207, 208 209 epiglottis, 72, 73, 73f epinephrine, 114 exercise and, 489 functions of, a-5 as a medication, 566 stress, reaction to, 114, 114f synthesis of, 194 epithelial cells, 371 epithelial tissues, 371, 373 374 ergocalciferol, 377 see also vitamin d ergogenic aids, 503 507 erythrocyte hemolysis, 382, 383n erythrocyte protoporphyrin, 446, e-20t, e-21t erythrocytes. -see red blood cells erythropoietin, a-3, a-6 escherichia coli, 665t, 666 esophageal sphincter, 72, 73f, 74, 76, 76f esophagus, 72, 73f, 74 essential nutrients, 7 conditionally essential nutrients, 156, 183, 345 essential amino acids, 182t, 183, 195, 196, d-1t essential fatty acids, 154 155, 154f, 520 water as, 397 estimated average requirement (ear), 16 17, 17f, 18f, 19, 21f estimated energy requirement (eer), 18, 257, f-2t, inside front cover estrogen replacement therapy, 434 estrogens, a-3, a-7 adipose tissue and, 266 breast cancer and, 266, 643 contraceptives and lactation, 537 fat cell metabolism, 282 grapefruit juice and, 617t heart disease risk, 628 osteoporosis and, 434 phytoestrogens, 434, 469 470, 470t, 472f selective estrogen-receptor modulator (serm), 434n ethanol (ethyl alcohol). -see alcohol ethnic foods, 4, 46, 46t, 61 ethyl alcohol. -see alcohol evening primrose oil, 658t exchange lists, 47 48, g-1 to g-11 canadian system, i-1, i-8t to i-11t carbohydrates and, 48, g-1t, g-6t combination foods, g-11t controlling energy and fat, g-2 diet planning, 48, g-3t fat, 48, g-1t, g-2, g-8t, g-9t food group plans and, 47 48 free foods, g-10t fruit, g-1t, g-3t, g-5t labels and, g-2f meat/meat substitutes, 47, g-1t, g-3t, g-8t milk, 47, g-1t, g-3t, g-5t protein and, 47 starch, 48, g-1, g-1t, g-4t vegetables, 48, g-1t, g-3t, g-7t websites on, 61 exercise, defined, 477 see also athletes; physical activity in-12 index exocrine glands, 78, a-4f exogenous protein, 193 experimental groups, 12, 14 experiments. -see research extracellular fluid, 398, 399f eyes. -see vision f facilitated diffusion, 81f, 108 fad diets, 290, 315 321, 316t, 317t, 320t see also quackery/quacks fad (flavin adenine dinucleotide), 328, 329, 330f, 347f, 348, c-5f faith healing, 653 falling, 431, 595 false negative, 354 false positive, 354 famine, 705 706, 706f dietary fat and, 150, 155, 227t distribution of, 260 263, 260f, 262f, 263f, e-16t energy, using for, 156, 156n, 489 energy balance and, 249 250 estrogen and, 266 exercise and, 301 302, 489 fasting, effects of, 234f, 235 functions of, 145, 153 155, 262 glycolipids, 112 health risks, 263 266, 263n kcalories (kcal) in, 156, 156n, 249 250, 489 longevity and, 597 measurement of, 261, 263, 264f, e-14 to e-16, e-16t storage of, 139, 150, 155 156, 232, 282, 283f upper-body, 262 263, 263f white vs. brown adipose tissue, 286 see also body composition; body mass index see also hunger, chronic/world (bmi); obesity; overweight fao (food and agricultural organization), 19, fats (chemistry), 139 144 26, 121, 664 see also who farming. -see agriculture fas. -see fetal alcohol syndrome fast foods adolescents and, 578 nutrient composition of, h-58 to h-77 overeating, 287 salt/sodium in, 456 trans fats in, 159, 177 vitamin a and, 376 fasting alcohol metabolism and, 240 carbohydrates and, 234, 234f effects of, 233 236, 234f fat metabolism during, 156, 234f, 235 health and, 597 ketosis and, 156, 235, 235f proteins (body) and, 234 235, 234f, 240 see also anorexia nervosa; eating disorders; malnutrition; starvation fat cells. -see adipose tissue fat-free foods, 296 fat-free milk, 53 fatigue, causes of, 348, 447, 448 fat metabolism overview of, 155 156, 222 223, 223f, 224f acid-base balance, 113 carbohydrates and, 226, 228n fasting and, 156 genetics and, 210 ketone bodies and, 113 lipoprotein lipase, 155, 282 283 liver and, 215t on low-kcalorie diet, 235 oxidation/tca cycle, 228n, 231f synthesis of fatty acids, 222 see also fats (chemistry); oxidation (of fats) fat replacers, 164 165 fats, artificial, 164 165 fats, defined, 139 fats (blood lipids). -see atherosclerosis; blood lipid profiles; cholesterol (blood); chylomicrons; hdl; ldl; lipoproteins; triglycerides; vldl fats (body), 153 155 abdominal fat/central obesity, 243, 262 263, 262f, 263f, 265, 301 302, 630 adipose tissue, 155 156, 155f, 266, 282 283, 283f, 284, 286 alcohol and, 240, 241, 241f, 243 from amino acids/protein, 194, 225, 227t in athletes, 258, 259, 261 262 calcium and, 416 from carbohydrates/glucose, 113, 120, 156, 222, 227t, 232, 233 chronic diseases and, 262, 263f, 265 266 diglycerides, 147 elements in, 7t firmness of, 142 glucose produced from, 156 hydrogenation of, 143, 144f kcalories (kcal) in, 9t monoglycerides, 147, 151f oxidation of. -see oxidation (of fats) phospholipids, 145 146, 146f stability/rancidity, 143 sterols, 146 147, 146n, 147f structure of, 139 144, 140f 146f, 141t, c-3t synthesis from protein, 194 terminology of, 141 types of, listed, 147 see also fat metabolism; fatty acids fats (dietary), 139, 141 177 absorption of, 83, 149 150, 152f alternatives to, 164 165 body s use of, 227t in breast milk, 550, 550f in breast milk vs. formula, 553f calculation of personal allowance, 165 in canadian food groups, i-11t cancer and, 159 160, 645 for children, 554, 560, 588 589 cooking with, 157, 163 degree of saturation in foods, 141t, 144f diabetes and, 641 dietary guidelines and, 40t digestion of, 78, 79f, 80t, 88, 147 149, 148f, 151f discretionary kcalories and, 45, 161 emulsification by bile, 78, 88, 148f, 149, 150f energy (kcal) in, 9t, 156, 156n, 160, 165 167, 229 230 in exchange lists, 48, g-1t, g-3t, g-9t for exercise, 488 489 in fad diets, 315 316 in fast foods, 159, 177, 287 in fish, 158 159, 158f, 159t, 174 food sources, 157f, 161 167, 162f, 166f in formulas, 553f fried foods and carcinogens, 644 645 health benefits from, 158 159, 172 175 heart disease and, 633. see under cardiovascular disease (cvd) in high-protein diets, 319 hydrogenated, 166f, 175 for infants/toddlers, 548, 554, 556 intake recommendations, 18, 160 167, 172 177, 175f, 176t, 489 intestinal motility and, 88 invisible, 163 on labels, 57, 58, 58, 58n, 165 167, 166f in low-carbohydrate diets, 318 319 in meats, 53, 65, 162, 162f, 175, 177, g-8t in milk and milk products, 53, 162, 162f, g-5t monounsaturated. -see monounsaturated fats obesity and, 160, 315 316 for older adults, 602 overeating and, 232, 233, 234f phospholipids, 145 146, 146f, 149 polyunsaturated. -see polyunsaturated fats protein-sparing action of, 112 rancidity, 143 recommendations for reducing, 161 167 satiating effect of, 252, 253f saturated. -see saturated fats sterols, 146 storage of, 155 156, 230 trans-. -see fatty acids, trans- transport of, 83, 149 150, 150 153, 152f, 153f unsaturated fatty acids, 141t, 142f, 144f, 176t, c-3t in usda food guide, 43f, 44, 47f in vegetarian diets, 65, 66, 67 websites on, 168 weight gain and low-fat foods, 296 for weight gain plans, 308 for weight loss plans, 295t, 296, 296t, 297f, 298 see also diets, high-fat; fatty acids fat-soluble vitamins. -see vitamins, fat-soluble fat substitutes, 164 165 fatty acids, 140 142 arachidonic acid, 154, 154f, 155, 550 in breast milk, 550 chemistry of, 154 155, 154f, c-3t cis-, 143, 145f deficiencies, 154, 155 dha (docosahexaenoic acid), 154, 159t, 174, 550 effect of alcohol on, 240, 241, 241f epa (eicosapentaenoic acid), 154, 159n, 159t, 174 essential, 154 155, 154f, 520. see also linoleic acid; linolenic acid exercise and, 489 fish oil, 158 159, 174, 605 medium-chain, 140, 152f metabolism of. -see fat metabolism monounsaturated. -see monounsaturated fats oxidation of. -see oxidation of fats polyunsaturated. -see polyunsaturated fatty acids (pufa) saturated. -see saturated fats structure of, 140 144, 140f 146f, 141t, 230f synthesis of, 154, 222 trans-. -see fatty acids, trans- unsaturated, 141, 142 144, 144f fatty acids, omega-3, 142 bone density and, 436 cancer risk and, 160, 645 chemistry of, 154 deficiency of, 155 eggs enriched with, 158 fetal development and, 520 in fish, 174, 676, 677 food sources, 67, 141t, 144f, 158, 159t, 176t health benefits from, 158 159, 174 health risks from, 159 heart disease and, 158, 627, 632t, 677 intake recommendations, 158 159 macular degeneration and, 605 in mediterranean diet, 177 in range-fed meat, 162, 177, 719 rheumatoid arthritis, 605 structure of, 141t, 142, 142f in vegetarian diets, 67 fatty acids, omega-6, 142 chemistry of, 154, 154f fetal development and, 520 food sources, 141t, 144f, 154, 159t, 176t heart disease and, 159 intake recommendations, 159 structure of, 141t, 142, 142f, 154f fatty acids, short-chain absorption of, 152f cholesterol synthesis and, 162 fiber fermented by bacteria, 108, 108n, 109f, 123 structure of, 140 types of, 108n fatty acids, trans-, 143 144 daily values and, 165 in dairy products, 143n food industry and, 175 food sources, 157, 159, 175, 176t, 633, h-0 health risks of, 143 144, 157, 633, 645 intake in u.s., 157 intake recommendations, 159 on labels, 58, 166f structure of, 143, 145f fatty liver, 198, 239, 240, 241 fatty streaks, 586 587 fda (food and drug administration), 360, 664 additive regulations, 682 683 artificial sweeteners approved, 132, 135, 136 food labeling, 55, 59, 59t functions of, 663, 664, 666 genetic engineering, 696 herbal supplements and, 656 infant formula regulation, 553 medwatch program, 690 olestra on labels, 165 pesticide regulations, 678, 679 protein labeling regulations, 196 supplements, 364, 365, 442 water safety, 689 websites/address, 33, 61 weight loss products and, 291n feasting, 232 233, 234f feces, 78 see also constipation; diarrhea feedback mechanisms, 87 feeding infants and toddlers study (fits), 561 562 female athlete triad, 270, 271f fermentable, defined, 106 ferritin, 443, 445, 446, 448 fertility/infertility, 246t, 264, 509, 526, 545, 676 ferulic acid, 470n fetal alcohol spectrum disorder, 543, 544 fetal alcohol syndrome (fas), 530, 543 545, 543f, 544, 545f fetal development, 510 515 overview of, 511f alcohol s effects on, 543 545, 543f, 545f caffeine and, 532 choline and, 345 critical periods, 512 515, 512f, 544 drugs, illicit and, 530 folate and, 338, 340, 340f infant birthweight. -see birthweight iodine and, 456 lead exposure, 531 malnutrition and, 515, 526 527 maternal weight and, 515 518, 518f mercury exposure, 531 nutrients influencing, 514 515, 520, 522, 524 vitamin a and, 372, 532 see also birth defects fetal programming, 515 fetus, 511f, 512 feverfew, 657t, 658t fiber, 101 overview of, 123t antidepressants and, 616 blood glucose levels and, 115 116 in breads/grains, 50f, 51, 51f, 122, 123, 125t calcium absorption, 418 cancer and, 122 123, 448, 645 chemistry of, 106, 107f, c-2, c-2f to c-3f in children s diets, 560 cholesterol and, 106, 122 constipation and, 95, 106, 122 diabetes and, 122, 123t, 640 dietary, 106 107 digestion/fermentation of, 78, 79f, 106, 108, 108n, 109f energy from, 108, 108n, 109 excess intake of, 123 124 food sources, 106 108, 123t, 124 127, 125t in fruit/fruit juices, 53 functional, 106 107 functions of, 78, 106, 109f, 123t gastrointestinal health, 122, 123, 123t heart disease and, 122, 123t insoluble, 106, 123t iron absorption, 444, 448 on labels, 58, 126 127, 126f mineral absorption and, 124, 444, 448 for older adults, 602 quantities in foods, 125t recommended intake of, 124 127, 125t, 126f satiety and, 108, 252, 286 soluble/viscous, 106, 122, 123t, 622t supplements, 106 107, 123 total, 107 types of, 106 107 websites on, 127 in weight control, 123 for weight loss, 295t, 297 298 fibrin, 192, 384f fibrocystic breast disease, 382 fibrosis, 239, 241 fight-or-flight, 598, a-5 see also epinephrine filtered water, 400 fish oils health benefits of, 159, 160 heart disease and, 159, 622t, 632t macular degeneration and, 605 rheumatoid arthritis and, 605 supplements, 159, 159n, 531 ulcers and, 13f fish/seafood bioaccumulation of toxins, 675f, 676 677 as calcium source, 417f, 420 cancer and, 644, 645 cholesterol in, 158f environmental issues, 670, 710, 717 essential fatty acids, 158 159 fat intake and, 159 heart disease and, 158 159, 174, 622t iodine in, 456 lipids in, 158 159, 158f, 159t, 174 mercury contamination of, 159, 174, 531, 675 676, 676 677 during pregnancy/lactation, 174, 531 regulation of, 676 safe cooking/handling of, 670 671, 670n, 671t trans fats and, 159 tuna, 676 usda food guide, 43f fit and fat, 266 fitness, 477 501 benefits of, 478 480 guidelines for, 480 484, 480t overweight and, 266, 288 289 program sample, 483t websites on, 499 500 see also athletes; physical activity 5 to 9 a day campaign, 52, 52f, 61 flavin adenine dinucleotide (fad), 328, 329, 330f, 347f, 348, c-5f flavin mononucleotide (fmn), 328, 329, c-5f flavonoids, 469, 470t, 471, 472f flavor enhancers, 685 flaxseed, 469, 470t, 472f index in-13 flaxseed oil, 144f flexibility, 480, 480t flora, 86 flours, 50f see also grains fluid balance, 190 191 alcohol use and, 243 athletes and, 271 272, 496 diarrhea and, 93 disruption of, 406 in eating disorders, 275 exercise and, 493 496, 494t maintaining, 190 191, 402 406, 402f, 404f, 404t, 405f minerals/electrolytes, 404 405, 404f, 404t, 409, 413 regulation of, 409, 410 replacing losses, 406 water balance, 398 401, 399f, 399t see also electrolytes fluorapatite, 460 fluoridated water, 460 461, 461f, 689 fluoride, 460 461, 461f, 461t, 464t, 551, 551t fluorosis, 460 461, 461f fluoxetine (prozac) for bulimia nervosa, 276 fmn (flavin mononucleotide), 328, 329, c-5f folate, 338 342, 356t overview of, 342t absorption/activation, 338, 339f alcohol abuse and, 243 244 bioavailability, 338, 340 birth defects and, 338, 340, 340f, 514 515 cancer and, 341 deficiency, 338 341, 342t, 553, 617 dietary folate equivalents (dfe), 338, 339 enterohepatic circulation of, 338 food sources, 341, 342f, 342t in fortified foods, 51, 51f, 340, 340f, 340n, 514 515 functions of, 338, 340 341 gene expression and, 208, 209f heart disease and, 340 341 medication antagonists, 617, 617n methotrexate and, 617, 617f pregnancy and, 338, 340, 514 515, 520, 521f rda/recommendations, 338, 342f, 514 serum levels, e-22, e-22t structure of, 339f, 617f, c-7f supplements, 338, 340, 514 vitamin b12 and, 340, 341, 343 344, 344f folate deficiency anemia, 341, e-20t, e-22, e-22t folic acid. -see folate follicle-stimulating hormone (fsh), a-4 follicle-stimulating hormone releasing hormone (fsh-rh), a-4, a-5 follicular hyperkeratosis, 373f fontanel, 381f food allergies. -see allergies food and agricultural organization. -see fao food and drug administration (fda). -see fda (food and drug administration) food and nutrition board, 16n food assistance programs for older adults, 608 609 in schools, 573 575, 574t in the u.s., 703 704 websites/addresses, 712t, 713 wic, 527, 529, 536, 539 food aversion (during pregnancy), 525 food banks, 704 food biotechnology, 693 697 foodborne diseases active surveillance network (foodnet), 666n foodborne illnesses, 664 673 botulism, 118n, 556, 556n, 665t, 666, 671 dietary guidelines and, 40t food industry and, 666, 667f in-14 index foodborne illnesses, continued in infants, 556, 557 in older adults, 610 during pregnancy, 531 preventing, 531, 665t, 666, 667 671, 667f, 669t, 671t safety hotlines, 670 symptoms of, 664, 665t travelers and, 672, 673 types/sources of, 665t viruses, 665t, 669 websites on, 667f, 690 food chain, 675, 676 food choices hunger and environmentalism, 711 713 motivations for, 3 5 for older adults, 607 611 see also diet planning food combining myth, 81 82 food composition, 6, 7t, 9, 250 251 food composition data, 266, h-0 to h-77t food craving (during pregnancy), 525 food frequency questionnaire, e-4 food group plans, 41 53 canadian, i-2f to i-7f for children, 561f energy and, 41, 41t, 44, 44t ethnic foods in, 46, 46t exchange lists and, 47 48 exchange lists combined with, g-3t, g-3 to g-4 miscellaneous foods in, 43f mixtures of foods in, 46 mypyramid, 47, 47f, 65 66, 66f, 561f nutrient density and, 42f 43f, 45 usda food guide, 42f 43f food guide pyramid. -see mypyramid food-hypersensitivity reactions, 565 see also allergies food industry added sugars, 117 121 additives, 682 687 advertising, 287, 569 antioxidants, 143, 354, 684 artificial sweeteners, 132 135, 133t, 134f, 135t emulsifiers, 145 energy use by, 717 fat replacers, 164 165 fiber supplements, 106 107 foodborne illnesses, 666, 667f functional foods, 5, 471, 472 genetic engineering, 693 697, 697t health claims on labels, 59, 59t healthy choices, 5, 164, 177 hydrogenation of fats, 143, 175 irradiation of foods, 672 673 sugar replacers used, 136, 136t, 137f supplements, 203, 364, 390, 461, 503 trans-fatty acids, 175, 177 tropical oils, 142, 175 see also fast foods; processed foods food insecurity, 702, 703 food insufficiency, 702 food intake. -see appetite; diet history; hunger food intolerances, 566 see also allergies food intoxications, 665t, 666 food labeling. -see labeling food pantries, 704 food poisoning, 664 see also foodborne illnesses food poverty, 702 food production. -see agriculture food records, 304f, e-4 food recovery, 704 foods, 3 as alternative medicines, 655 healing powers of, 469 473 vs. supplements, 19, 349, 363, 365, 392 393, 471, 604 foods, functional, 5, 469, 471 473 food safety concerns. -see environmental contaminants; foodborne illnesses; safety; toxicity food safety inspection service (fsis), 666n food security, 702 food stamp program, 703 704 food substitutes, 53 food surveys research group website, 26 formaldehyde, 134 formulas. -see infant formulas fortified (enriched) foods, 50 52 baby foods, 556 biofortification, 694 bread/grains, 50 51, 51f, 340, 340n, 450, 514 breakfast cereals, 51 52 calcium, 420 eggs/omega-3 fatty acids, 159 folate, 51, 51f, 340, 340f, 340n, 514 515 for infants, 67 iodized salt, 456 iron, 50, 51f, 448, 450, 556 margarine, 471, 472, 472n, 633 milk: vitamin a, 53, 375, 375n milk: vitamin d, 53, 330, 330n, 379, 379n nutrient additives, 685 soy milk, 53 for vegans, 67 vitamin b12, 67 vitamin d, 418 see also functional foods fosamax, 434n fossil fuels, 709, 717, 719f foxglove, 655f, 657, 658 fraud, 30, 32, 33, 34, 34f see also information on nutrition, validity of; quackery/quacks free radicals, 351, 390 in aging, 597 alzheimer s disease and, 606 607 atherosclerosis, 627 cancer and, 444 chemical reactions of, 390 392, 391f, b-8 copper and, 458 disease and, 390 392 iron and, 444, 445 oxygen-derived, 390, 390n, 391 vitamin c and, 351, 351f, 352, 391, 392 vitamin e and, 382, 391, 392 zinc and, 452 see also antioxidants; oxidative stress frequency (of exercise), 480 fructose, 103 absorption of, 108, 110f body fat and, 120 metabolism of, c-10 structure of, 102n, 103f sweetness of, 103, 116 fruit juices, 617 in exchange lists, g-5t grapefruit, 617, 617t for infants/children, 553, 556 intake recommendations, 42f, 53 tooth decay and, 553 fruits antioxidants in, 391 392, 393 in canadian food groups, i-9t cancer and, 392, 470, 643, 644t, 645, 646t carbohydrate content of, 126 dental caries and, 119 discretionary kcalories and, 45 dried, 65, 119 in exchange lists, g-1t, g-3t, g-5t fat intake and, 162 163 fiber content of, 125t 5 to 9 a day campaign, 52f in food group plans, 41t, 42f, 46t, 47f, 48t, 52 53, i-4f glycemic index of, 116f heart disease and, 392, 471, 630, 633 nutrient density, 39, 119 nutrients in, 42f, 65 phytochemicals in, 471, 472f sugar content, 119, 126 websites on, 52f, 61 fsh (follicle-stimulating hormone), a-4 fsh/lh-releasing hormone (fsh/lh-rh), a-5 ftc (federal trade commission), 365 fuel, 213 functional foods, 5, 469, 471 473 see also fortified (enriched) foods; phytochemicals g galactose, 103 absorption of, 108 109, 110f metabolism of, 219f, c-10 structure of, 103f, 104f, c-2f, c-3f gallbladder, 72 anatomy of gi tract, 73f, 74 fat digestion and, 78, 88, 148f, 149 see also bile gallbladder disease, 478 gamma-linolenic acid, 154n gamma-oryzanol, 504 gangrene, 640 gardening, 712 garlic, 472f, 657t, 658t gas, intestinal, 95 96, 97t gastric acidity, 77, 87, 97, 413, a-6 gastric glands, 77, 78 gastric juices, 75, 77, 78 gastric lipase, 148f, 149 gastrin, 87, 88t, a-6 gastritis, atrophic, 343, 599 gastroenteritis, 665t gastrointestinal reflux, 94, 96 97, 96f, 97t gastrointestinal reflux disease (gerd), 94 gastrointestinal tract. -see gi (gastrointestinal) tract gatekeepers, 571, 578 gelatin, 195 gender differences alcohol intoxication, 240 blood alcohol levels, 243t bmr and, 255t, 256, 257 body composition, 6f, 260, 262, 263f, 576 eating disorders, 271, 272, 274 energy needs, 44t, 254, 255t, 256, 257, 577 fat cells and lpl, 282 heart disease risk, 628 iron needs, 449, 576 577, 603 iron status, 446, 448 osteoporosis risk, 432, 433t, 436 gene expression, 189, 207, 208, 452 gene pool, 286 generally recognized as safe (gras) list, 682, 696, h-0 genes, 207 see also genetics/genes genetic abnormalities. -see birth defects; genetic disorders genetically engineered (ge) foods, 566, 693 697 genetically modified (gm) foods, 693 697 genetic disorders disease and, 209 210 down syndrome, 340, 530 hemophilia, 384 intrinsic factor and, 343 iron overload, 448 menkes disease, 459 phenylketonuria (pku), 134 135, 183, 207, 209 prader-willi syndrome, 284, 285 sickle-cell anemia, 189, 189f wilson s disease, 459 genetic engineering, 687, 693 697, 694f, 697t genetics/genes, 207 cancer risk and, 642 chromosomes, a-2 chronic disease risks, 625, 625f, 647 diabetes, type 1, 115 diabetes, type 2, 638 energy restriction and, 596 epigenetics, 189 fetal programming, 515 gene expression, 189, 207, 208 health history and, 20 heart disease risk, 210, 586, 628 hypertension and, 634 635 lifestyle, synergistic with, 625 lipoproteins and, 152 loss of diversity in food crops, 710, 717 obesity and, 284 285, 316t, 567, 597 ob gene (obesity), 283, 285f osteoporosis risk, 435 protein synthesis and, 189 sequencing errors, 187, 189 single nucleotide polymorphisms, 210 see also dna genetic test kits, 207 genistein, 470t genome/genomics, 11, 207, 208 209, 647 genomics, nutritional, 11, 207 211 dri and, 16 during fetal development, 515 genetic variation and disease, 209 210 health care ramifications, 210, 647 lipoproteins, 152, 210 protein synthesis and, 189 slow-aging and energy intake, 597 see also genetics/genes genotoxicants, 686 geophagia, 447, 525, 653 germanium, 656 germ (of grains), 50, 50f gestation, 512 gestational diabetes, 528, 539 ghih (somatostatin), a-5 gh-releasing hormone (grh), a-4 ghrelin, 285 286, 292 gh (somatotropin), a-5 giardiasis, 665t gi (gastrointestinal) tract, 72 89 alcohol abuse and, 244 anatomy of, 72 76, 73f, 75f, 76f, 78f, 79f, 81 83, 82f carbohydrate digestion in, 87, 108, 109f cell replacement, 6, 190 in eating disorders, 273, 275 fat digestion in, 148f fiber and, 78, 122 123 fiber and carbohydrates, 107 108, 109f, 122 fluids and electrolyte balance, 406 folate and, 339f hormones produced in, 86 88, 88t, a-6 to a-7 hunger and, 251 in infants, 552 lymphatic system and, 82, 83, 84 85, 84f in older adults, 599 problems with, 92 98, 97t, 123, 123t, 165, 343. see also constipation; diarrhea; foodborne illnesses; heartburn; vomiting promoting health of, 86, 88 89, 123t protective factors, 77, 78 protein digestion in, 186f regulation of, 86 89, 88t secretions of, 76 78, 76f, 86 88 vitamin a and, 371, 373 374 websites on, 90, 98 see also absorption; colon (large intestine); digestion; intestinal bacteria; small intestines ginger, 657t, 658t ginkgo biloba, 654f, 657t, 658 ginseng, 654f, 657t, 658t glands, 78, 80t, a-3 to a-7, a-4f see also specific glands gliomas, 642 glossitis, 330n, 333n, 349f glucagon, 113 function of, 113, 114, 191t, a-5 secretion of, 113n, 114f glucocorticoids, a-4, a-5 glucogenic amino acids, 194n, 221f, 225, 225f gluconeogenesis, 112 biotin and, 334 glycerol and, 156, 222, 223 proteins/amino acids and, 112, 192, 194, 225, 225f, 234 235 glucosamine, 606 glucose, 102, 111 117 absorption of, 108 109, 110f, 122. see also glycemic index; glycemic response chemistry of, 102 103 conversion to fat, 113, 222, 227t depletion of, 487 in diabetes, 639 640, 639f energy content of, 230 exercise and, 485 488, 485t, 486f fasting, effects of, 232 233, 234f function of, 111 112 liver and, 105n, 107, 110f, 113, 114, 215t, 221 metabolism of, 114f, 115 116, 219 222, 219f 222f, 233, c-15t in polysaccharides, 106f produced from fat/glycerol, 156, 222 produced from lactate, 220f, 221, 487 produced from proteins/amino acids, 112, index in-15 glycolysis, 219 222 atp produced, 219f 222f, 222, c-15n, c-15t location of reactions, a-2n pathways, 219f 222f, c-10f glycoproteins, 112, 639 gm foods, 693 697, 694f, 697t goat s milk, 341, 553 goblet cells, 80, 82f, 371, 373 goiters, 13f, 456, 456f goitrogens, 456, 677 goldberger, joseph, 332n, 357 goldenseal, 657t golgi apparatus, a-2, a-3, a-3f gout, 354, 606 government policies, hunger and, 703 704, 711 government resources safety hotlines, 670, 680 websites, 26, 33, 61, 499 500 wic, 527, 529, 539 see also fda; usda grains, 50 51 breakfast cereals, 51 52, 412, 412f, 555 556 in canadian food groups, i-8t, i-9t carbohydrate content of, 125, 126f corn, 332, 693 discretionary kcalories and, 45 in exchange lists, g-4t fat intake and, 162 163 fiber content, 50f, 51f, 51, 125t, 126f flours, types of, 50f folate fortification, 51, 51f, 340, 340n, 514 in food group plans, 41t, 42f, 47f, 48t, 49f glycemic index of, 116f iron content, 449, 450 meat production and, 717f, 718 nutrients in, 42f, 50 51, 50f, 51f phytates in, 409 proteins, complementary, 196f refined/enriched, 50 51, 50f, 51f, 449, 450 in usda food guide, 41t, 46t, 48t wheat, 50 51, 50f whole. -see grains, whole see also breads 192, 194, 225, 225f, 234 235 grains, whole, 50, 51f produced from pyruvate, 220 in sports drinks, 495 storage of. -see glycogen structure of, 102f 104f, 230f, c-1f see also blood glucose levels; carbohydrates; gluconeogenesis glucose polymers, 495 glucose tolerance, impaired, 637 glucose tolerance factor (gtf), 461 glucuronic acid, c-3f glutamate, folate and, 338, 339f glutathione peroxidase, 391n glycemic index, 115 116, 116f, 316, 488 glycemic response, 115 116, 136, 640 glycerol, 142 absorption of, 152f glucose from, 222, 223 metabolism of, 222 223, 224f, c-10 structure of, 142f, 143f glycine, 182f glycobiology, 112 glycogen, 105 as energy storage, 105, 112, 114f, 486 488 exercise and, 485 488, 488t glucagon and, 113, 114f liver and, 105n, 112, 114f low-carbohydrate diets and, 319 metabolism of, 215f, 347f structure of, 105, 106f, c-2 glycogen depletion, 319, 487, 490 glycogen loading, 487 glycogen super compensation, 487 glycolipids, 112 cancer and, 645, 646t for children, 559 diabetes and, 122, 640 fiber content, 50f, 51f, 123, 125t, 126f heart disease and, 630, 633 nutrients in, 50, 51f in usda food guide, 42f, 47f wheat plant, 50f grapefruit juice, 617, 617t grapes, 472f gras (generally recognized as safe) list, 682, 696, h-0 grocery shopping diet planning and, 48 53 environmental issues, 712, 717 720, 717f, 718t, 719f fat intake and, 161 167, 166f food labels and, 54 61, 54f, 60t, 166f for older adults, 600, 608, 609 611 thrifty meals, 610, 704 see also cooking/food preparation growth during adolescence, 575 576, 577 bone development, 372, 421f, 435 436 energy needs during, 256, 547 549, 558 559, 576 of infants, 547 549, 547f iron deficiency and, 446 malnutrition and, 198, 453f, 562 measurement of, e-6 to e-7, e-6f to e-13f obesity and, 569 phosphorus and, 422 protein and, 190, 548 549 in-16 index growth, continued vitamin a and, 372 vitamin d and, 37f, 377 zinc deficiency, 453, 453f see also fetal development growth charts, 548f, e-8f to e-13f growth hormone (gh), 191t, a-4 gtf (glucose tolerance factor), 461 guidelines for healthy eating (canada), 40t gums (fiber), 106n, 685 h habit and food choice, 4, 304 see also lifestyle choices hair, e-17t hard liquor, 238, 239, 244t hard water, 400 hazard analysis critical control points (haccp), 666 hazards, 663 see also safety hcl. -see hydrochloric acid (hcl) hdl (high-density lipoprotein), 152 blood levels, 156, 157, 628t composition of, 151n, 153f dash eating plan, 636 function of, 152 heart disease risk, 152, 628t, 629, 631 ldl ratio to, 152, 629 in obese children, 587 size and density of, 153f trans-fatty acids and, 157 head circumference, e-7 health overview of, 24 25 body composition and, 258 266, 260f, 263f, 264f. -see also under obesity food choices for, 5 status. -see nutrition assessment; nutrition status strategies for older adults, 608t websites, 648 see also disease health canada website, 33 health care professionals in alternative health, 652, 659 certified lactation consultants, 534 dietetic technicians, 32 dietitian career descriptions, 32 nutrition education of, 31, 32 nutritionists, 32 physicians, 31 public health dietitians, 32 registered dietitians, 19, 32 websites for, 33, 34 health claims, 59 food choices and, 5 on food labels, 59, 59t on supplement labels, 364 see also information on nutrition, validity of health history, 20 21, 22f, e-2, e-2t healthy people 2010, 23, 23t, 26, 532, j-1t to j-2t heart attacks, 626 blood cholesterol and, 13f, 157 c-reactive protein and, 627 death rate, 628 mechanism of, 627 628 obesity and, 265 plaque and, 629 see also cardiovascular disease (cvd) heartburn, 94 causes of, 77, 96 97 during pregnancy, 524t, 525 preventing, 97t heart disease. -see cardiovascular disease (cvd) heart rate, 482 heat cramps, 495 heat energy atp and, 216 generation of, 253 254 kcalorie as unit of, 7 9, 250 white vs. brown adipose tissue, 286 heat stroke, 493 494 heavy metals, 463 see also specific metals height measurement, e-6, e-6f heimlich maneuver, 92, 93f, 94 helicobacter pylori, 97, 98, 343 hematocrit, 446, e-20, e-20t, e-21t heme iron, 443 444, 444f hemicelluloses, 106n, c-2f to c-3f hemochromatosis, 448 hemoglobin, 184 copper and, 458 function of, 184 in iron deficiency, 446, e-19 to e-20, e-20t, e-21t iron in, 184f, 443 444 in sickle-cell anemia, 189, 189f structure of, 184f hemolytic anemia, 382 hemophilia, 384 hemorrhagic disease, 384 hemorrhoids, 94, 94, 122, 525 hemosiderin, 445, 448 hemosiderosis, 448 hepatic portal vein, 83, 85f hepatic vein, 83, 85f hepatitis, 665t hepatitis a virus, 670 hepcidin, 445, 448 herbal medicines/supplements, 655 659 for athletes, 505 dosage, 657 herbal medicines, 653 herb-drug interactions, 657 658, 658t labeling of, 657, 658 lactation and, 537 natural vs. safe, 34f, 656 obesity treatment, 290, 291t precautions, 656t, 657t, 658t during pregnancy, 530 websites on, 659 herbal sterols, 505 heredity. -see genetics/genes herpes, 203 hesperidin, 346 heterocyclicamines, 644n hexoses, 102 hgh (human growth hormone), 503, 506 hiccups, 94, 96 high blood pressure. -see hypertension high-carbohydrate diets. -see diets, high- carbohydrate high-density lipoprotein. -see hdl high potency, 360, 361, 364 high-quality protein, 195 high-risk pregnancy, 525 532, 526t histamine, 352 historical data (in nutrition assessment), 20 21, 22f, e-1 to e-5, e-2t hiv (human immunodeficiency virus), 536 537, 623 624, 624t hmb (beta-hydroxy-beta-methylbutyrate), 504 homeopathy, 653 homeostasis, 86 blood glucose, 113, 114f calcium, 417 418, 417f nervous system and, a-7 to a-8 potassium, 414 set-point theory and, 283 water balance, 398, 401 see also acid-base balance; electrolytes homocysteine alcohol abuse and, 244 folate and, 340 341 heart disease risk, 199, 340 341, 628 629 honey, 118 botulism risk, 118n, 556, 671 fructose in, 102 nutrients in, 118 119, 118t hormonal athletic supplements, 505 506, 506t hormones, 87, a-4 overview of, a-3 to a-7, a-4f blood glucose levels and, 113 114, 114f blood pressure and, 401 402, a-6 bone remodeling, 416, 417, 417f, 432 calcium balance and, 416, 417f, a-6 changes with age, 598n cholesterol in synthesis of, 147 energy metabolism and, a-5 to a-6 fat storage and, 416 functions of, 190, 191n, 191t gastrointestinal, 86 88, 88t, 149, a-6 to a-7 as incidental food additives, 686 687 iron balance, 445, 448 lactation and, 533, a-5 nervous system and, 86 88 obesity/appetite, 284 286 osteoporosis and, 434 435, 434n pregnancy and, a-6 proteins as, 190 regulation of, a-4 satiety and, 251, 252, 284 286 sex, a-7. -see also estrogens; testosterone stress and, a-4, a-5 synthesis of, 147, 194 vitamin c and, 352 vitamin d, 377, a-6 weight control and, 284 286 see also phytosterols; specific hormones hormone-sensitive lipase, 156 hourly sweat rate, 494 human genome, 207, 211 see also genome/genomics human genome project, 207 human growth hormone. -see hgh (human growth hormone) human intervention research, 13f, 14t human milk. -see breast milk hunger, chronic/world, 701 714 in children, 197 199, 197t, 562 564, 563t environmental degradation and, 709 710 food supply and, 709 710 malnutrition, 197 199, 197t, 706 707 overpopulation and, 707 709, 708f reasons for famines, 705 706, 706f relief organizations, 712t solutions, 199, 701, 703 704, 710 713 statistics, 701, 702, 702f, 704, 706, 706f, 707 united states, 702 705, 702f websites on, 713 hunger (sensation), 251 253 academic performance and, 562, 563 factors affecting, 251 253, 252f, 253f fiber and, 123 protein and, 318 smoking and, 579 see also appetite; satiety husk, 50f hydration. -see dehydration hydrochloric acid (hcl), 78 acid-base balance, 413, 413n functions of, 77, 185, 186f metabolic alkalosis and vomiting, 413n hydrodensitometry, 264f, e-15, e-16t hydrogenation (of fats), 143 in convenience foods, 175 on labels, 166f in margarine vs. butter, 166f structure change, 144f trans fats and, 157 hydrogen peroxide, b-8, b-8f hydrolysis, 77 of atp, 216, 217f by digestive enzymes, 76 of disaccharides, 104, 104f of triglycerides, 148f, 149, 151f, 155 hydrophilic, 147 hydrophobic, 147 hydrotherapy, 653 hydroxyapatite, 416 hydroxycitric acid, 291t hydroxylysine, 352 hydroxyproline, 182n, 352 hyperactivity, 120, 564 565, 581 hypercarotenemia, 377n hyperglycemia, 246t, 637, 638 hyperkeratinization, 373f hyperplastic obesity, 283 hypertension, 626, 632 637 calcium and, 416 in children, 569, 587 588 development of, 632 634 drug therapy, 636 637 essential, 626 exercise and, 636 guidelines for, 628t heart disease risk, 627, 628t, 629, 632 magnesium and, 424 mao inhibitors and, 617 nutrient-gene interactions, 515 obesity and, 265, 569, 635 omega-3 fatty acids and, 158 potassium and, 414 pregnancy and, 528, 528n prehypertension, 626, 628, 628t primary vs. secondary, 626 risk factor summary, 634 635 salt sensitivity and, 410 sodium and, 400, 410 411, 635t, 636, 636t treatment of, 635 637, 635t in vegetarians, 65 hyperthermia, 493 494, 579 hypertrophic obesity, 283 hypertrophy (muscle), 481 hypnotherapy, 653 hypoallergenic formulas, 553 hypoglycemia, 115, 246t, 641 hyponatremia, 398, 412, 495 496 hypothalamus, 251 hormones produced by, a-4 to a-5 hunger and, 251 location of, a-4f water balance and, 398, 403f hypothermia, 494 hypothesis, 11, 12f, 14 hypothyroidism, 456 i igf-1 (insulin-like growth factor 1), e-19, e-19n ileocecal valve, 72, 73f, 74, 76 ileum, 72, 73f, 74 imagery, 653 imitation foods, 53 immune system, 622 alcohol and, 241 allergies and, 565 566 antibodies, 192, 622 antigens, 192 breastfeeding and, 551 552 components of, 622 623 deficiencies, effects of, 599 eicosanoids and, 154, 159n exercise and, 478n free radicals and, 390 heart disease and, 627 malnutrition and, 623, 623f, 623t in older adults, 599 overweight and, 265 rheumatoid arthritis and, 605 vitamin c and, 352 see also allergies immunity, 192 immunoglobulins, 622 implantation (of zygote), 510 imported foods, 666, 678 679 incidental additives, 685 687 indigestion, 94, 96 97, 97t indirect additives, 685 687 indirect calorimetry, 250 indispensable nutrients, 7 indoles, 470t infant formulas, 552 553 allergies and, 553 fatty acids in, 550 health and, 533t, 536, 553 health beverages replacing, 379 soy, 67, 553, 557 vision and mental development, 550 551 infants, 547 558 basal metabolic rate, 254 birth defects. -see birth defects birthweight, 515 516, 545, 554 blood calcium, 417n botulism in, 556, 556n, 671 of drug users, 530 energy needs of, 547 548, 549f fat-free diets, 155 fat needs, 548, 554, 556 feeding skills of, 555t goat s milk anemia, 341 growth rate, 547 548, 547f, e-6 to e-7, e-6f to e-10f healthy people 2010 goals, j-2t honey and botulism, 556 iron needs, 551, 551t, 556 low birthweight, 525 526 malnutrition, 379, 706, e-7 mental development, 550 milk, 554, 557, 557f mineral needs, 549, 549f, 551, 551t pesticides and, 678, 681 post term, 516 premature, 516 preterm, 516, 525 526, 530, 554 protein needs, 548 549, 549f, 550, 550f, 553f solid foods for, 555 557, 555t, 557f supplements, 384 385, 551, 551t term, 516 vegetable/fruit intake, 561 562 vegetarian diets, 557 vitamin k, 384 385 vitamin needs, 549, 549f, 551t, 556 vomiting in, 93 water intake, 549 websites on, 580 581 see also breastfeeding; children; fetal develop- ment; pregnancy; rickets infections/infectious disease, 621 624 botulism, 118n, 556, 556n, 665t, 666, 671 breastfeeding and, 536 537, 551 children and, 372 373, 455 colds, 12 15, 352, 455, 478 from contaminated water, 553 deaths from, 24t, 199 in diabetics, 639 640 dysentery, 198 199 e. coli infection, 665t, 666 exercise and, 478 helicobacter pylori, 97, 343 hiv/aids, 536 537, 623 624, 624t in infants, 551, 556, 671 iron overload and, 448 lead toxicity and, 463 malnutrition and, 197, 198 199, 453 454, 707 index in-17 measles, 199, 372 373 in older adults, 599 tuberculosis, 336 vitamin a and, 372 373 zinc and, 453, 455 see also foodborne illnesses infertility/fertility, 246t, 264, 509, 526, 545, 676 inflammation, 265 cancer and, 642 heart disease and, 626 627 rheumatoid arthritis, 605 vitamin e and, 382 information on nutrition, validity of, 30 34 alternative medicine, 652 659 ergogenic aids, 503 experts/professionals, 31 33 fad diets, 315 321, 316t, 317t, 320t functional foods/phytochemicals, 473 herbal medicines, 656t, 657t, 658, 658t internet sites, 30, 31f, 33, 34 naive vs. accurate view of needs, 18f news reports, 30 31 red flags of quackery, 33, 34f scientific research, 15 16 supplements, 362, 363 364, 503 vitamin impostors, 346 websites on, 33, 34, 659 weight loss, 289 291, 290t, 291t see also myths inh (isonicotinic acid hydrazide), 336, 336n initiators (cancer), 642, 643 645, 643f inorganic, 7 inorganic nutrients, 7t inositol, 346, 364 insensible water losses, 399n insoluble fibers, 106, 123t see also fiber. -insulin, 113 chromium and blood glucose, 461 diabetes and, 115, 637, 638, 639f, 641 fad diet claims, 316, 316t functions of, 113, 114, 114f, 190, 191t, 316t, 637 hormones effected by, a-4 impaired glucose tolerance, 637 structure of, 184f sugar intake and, 120 zinc and, 452 see also blood glucose levels insulin-like growth factor 1 (igf-1), e-19, e-19n insulin resistance, 265, 630 body weight and, 265 266, 316 mechanism of, 638 trans-fatty acids and, 157 integrative medicine, 652 intelligence, 552, 562, 563, 564, 565 intensity (of exercise), 480 intentional food additives, 683 685, 683t intermediate-density lipoprotein (idl), 151n intermittent claudication, 382 international food information council, 33 international system of units (si), 8 internet, 32, 364, 659 internet sites. -see websites interstitial fluid, 398, 399f intestinal bacteria biotin and, 334 cholesterol synthesis and, 162 fiber digestion, 78, 79f, 86, 106, 108, 108n, 109f, 122, 123 lactose intolerance and, 110, 111 as protective, 86 vitamin k and, 86, 383, 385n yogurt and, 86, 162 intestinal lipase, 148f intestines. -see colon (large intestine); gi (gastrointestinal) tract; small intestines in-18 index intra-abdominal fat, 262 263, 262f, 263f intracellular fluid, 398 intrinsic factor, 343 in vitro studies, 13f iodine, 455 457, 464t overview of, 457t deficiency, 13f, 456, 456f, 457t food sources, 456, 457t functions of, 455, 457t intake recommendations, 456, 457t selenium and, 442 toxicity, 67, 456, 457t websites on, 465 ions, 403, 404f, 404t, b-5, b-5 to b-6 see also electrolytes iridology, 653 iron, 442 451, 464t overview of, 451t adolescent needs, 576 577 for athletes, 492 493 blood losses and, 443n, 445, 446, 522 in breast milk, 551, 552 in cookware, 450 451 copper and, 458 ferrous/ferric, 442, 451, 458, b-7 food sources, 65, 66, 449 450, 450f, 451t functions of, 442 443, 445f, 451t heme vs. nonheme, 443 444, 444f for infants, 551, 551t, 556 intake recommendations, 449, 450f, 451t, 577 lactoferrin, 552 lead toxicity and, 463 losses of, 445, 445n, 446 manganese absorption and, 442 menstruation and, 360, 577 in milk, 554 during pregnancy/lactation, 446, 521f, 522, 529, 536 recycling, 445, 445f regulation/balance, 444, 445 storage, 443, 445, 445f supplements, 360, 361 362, 446, 448, 450 451 total iron-binding capacity (tibc), e-20 to e-21, e-21t toxicity, 361 362, 447 448, 451t transport of, 191, 443f, 444 445, 445f vegetarian diets, 65, 66 in whole grains, 51f zinc absorption and, 453, 522 iron absorption bioavailability, 450, 551, 554 caffeine and, 538 calcium and, 436 enhancing, 444, 446, 449, 450, 451, 522, 556 inhibition of, 444, 448, 449, 451, 525 mechanism of, 443 444, 443f, 444f, 445 mfp factor, 444, 450 from plant foods, 66 from supplements, 450 451, 522 vitamin c and, 66, 351, 354, 444, 448, 522 vitamin c and iron supplements, 451 see also iron overload iron cookware, 450 451 iron deficiency, 445 447 assessment of, 22, 446 in athletes, 492 atrophic gastritis, 343 in children/teens, 563, 577 lead absorption and, 564 in malnutrition, 198 statistics on, 445 446 symptoms of, 446, 447, 451t iron-deficiency anemia, 446 assessment of, e-19 to e-21, e-20t, e-21t in children, 560, 563 development of, 22, 446 447 exercise and, 492 493 in older adults, 603 during pregnancy, 529 red blood cells in, 446, 447f symptoms of, 37, 348, 446 447 iron overload, 354, 447 448, 450, 465 irradiation (of foods), 330, 330n, 672 673 irritable bowel syndrome, 93, 94 isoflavones, 470t isoleucine, 196f isomalt, 132, 136t isonicotinic acid hydrazide (inh), 336n, 618 isothiocyanates, 470n, 470t j jejunum, 72, 73f, 74 joule, 7 journals, 31f, 33 jun bu huan, 656 k kava, 657t, 658, 658t kcalorie (energy) control, 38, 596 597 kcalories (kcal), 7 in alcohol, 8, 9n, 243, 244t available from food, 8 9, 9t in beverages, 400 calculating, 9, 9f, 257 in carbohydrates, 9t discretionary. -see discretionary kcalorie allowance empty, 39, 298 as energy measurement, 7 9, 9f fad diets and, 318 in fast food, 287 from fat, reducing, 161 167, 162f, 166f in fat (body), 156, 156n, 249 250, 489 in fat (dietary), 9t, 156, 156n, 160, 165 167 in fat replacers, 164 in foods, measuring, 250 251, 250f, 251n in fruit juices, 556 on labels of foods, 54f, 56 57, 56t, 58 in lecithin, 146 in low-fat foods, 164 in mixers for alcohol, 244t nutrient density and, 38, 42 43f, 118 119, 118t in protein, 9t sugar intake and, 117 118, 118t, 120, 121 sugar replacers and, 132, 135 see also energy; energy density; energy metabolism; nutrient density kcalories (kcal) needs adolescents, 576 carbohydrate recommendations, 124 127 of children, 558 559, 560, 562t estimating requirements, 41, 41t, 44, 44t, 255t, 256 257 for exercise, 254, 254f, 255t, 257t, 300, 487, 497 for exercise: calculating, 44t, 257, f-1, f-2 to f-6t fat, intake recommendations, 160 161 gender differences, 44t, 254, 256, 577 of infants, 547 548, 549f during lactation, 534 535 of older adults, 44t, 601 602 during pregnancy, 520, 521f, 521n protein intake, as percentage, 201 recommendations (eer, amdr), 18 sugar intake and, 121 weight gain plans, 299t, 308 weight loss plans, 295 296, 295t, 299t kefir, 111 keratin, 373 keratinization, 373 374, 373f keratomalacia, 373 keshan disease, 457 keto acids, 225, 226f, 235 ketogenic amino acids, 194n, 221f, 225, 225f, 226f ketogenic diets. -see ketosis ketone bodies, 113 brain/nerves and, 156 in diabetes, 639f fat metabolism and, 113, 156 formation of, 235f, c-16 to c-17, c-17f ketosis, 113 adverse effects of, 235, 319 320, 320t alcohol use and, 241 dieting and, 319 320, 320t fasting/starvation, 156, 235 inadequate carbohydrate and, 113, 156 kidney disease alcohol as risk for, 246t cancer and, 644t diabetes and, 586, 640 healthy people 2010 goals, j-1t herbal medicine risk, 656 proteins (dietary) and, 200 water intoxication and, 398 see also kidney stones kidneys, functions of acid-base balance and, 407, 408, 410n amino acid metabolism, 194 blood pressure regulation, 401 402, 634 blood volume regulation, 401 402, 403f calcium balance in bone, 416, 417f fluids and electrolyte balance, 402 406, 402f, 404f, 404t, 405f hormones and, 401, 406, a-5, a-6 medications and, 617, 618 nephron function, 402f sodium/potassium, 406, 410 urea excretion, 226, 227f vitamin d activation, 377, 377f water balance, 399 kidney stones calcium and vitamin d, 379, 418 proteins (dietary) and, 200 vitamin c and, 354, 354n, 355n water intake and, 400 kilocalories. -see kcalories (kcal) kilograms (kg), 8, inside back cover kilojoule (kj), 7, 8, 9n, inside back cover kombucha tea, 656 krebs cycle. -see tca (krebs) cycle kwashiorkor, 197t, 199, 199f see also protein-energy malnutrition (pem) l labeling, 54 61 of allergens, 566 artificial sweeteners, 137f carbohydrate content, 125t, 126 127, 126f daily values, 54f, 55 57, 56t, 165 167, inside back cover exchange lists and, g-2f fat content, 165 167, 166f fiber content, 126 127, 126f glossary of terms, 58 gm foods, 696 health claims, 59, 59t, 363 364 herbal supplements, 657, 658 ingredient list, 54f, 55 nutrition facts, 54f, 55 56 organically grown crops, 681f phytochemicals, 473 protein content, 196 regulations for, 59, 59t, 60t, 196 serving sizes, 55 structure-function claims, 59, 60t, 364 sugar content, 58, 117, 118, 121 of supplements, 360, 364 365, 365f websites on, 61 laboratory studies, 13f, 14t laboratory tests, e-16 to e-22 exchange lists, g-4t, i-10t in food group plans, 41t, 43f, 44, 46t, 47f, blood glucose, 113 bone density, 432 cholesterol, 156 157, 587, 588t. -see also blood lipid profiles diabetes, 354 false positive/negative results, 354 iron deficiency, 446, e-19 to e-21, e-20t, e-21t nutrition assessment, 21 22, 22f, e-16 52, 52f, i-4f glycemic index of, 116f nutrients in, 43f, 44 proteins, complementary, 196f in recipes, 52f types of, 52 for vegetarians, 65, 66 see also plant foods; soy products to e-22, e-18t lactadherin, 552 lactase, 108, 110 111 lactase deficiency, 110 lactate (lactic acid), 220 alcohol and, 241 in breast milk, 535 exercise and, 221, 458t, 486 487, 535 metabolic pathways, 220 221, 220f, 221f lactation, 533 540 see also breastfeeding lactation consultants, certified, 534 lacteals, 85 lactitol, 132, 136t lactobacillus bifidus, 86, 551 552 lactoferrin, 552 lacto-ovo-vegetarians, 64, 66 lactose, 105 in breast milk and formula, 550 foods containing, 105, 111 in medications, 111, 618 structure of, 105, c-1f lactose intolerance, 110 111 ethnic differences, 111 formulas for infants with, 553 websites on, 127 lactovegetarians, 64 laetrile, 346, 653, 677 laleche league international, 539 large intestine, 72, 73f see also colon (large intestine) larynx, 92, 92f, 94 laxatives, 94, 95, 290 291 ldl (low-density lipoprotein), 151 blood levels, 156, 157, 588t, 628t composition of, 151n, 153f dash eating plan, 636 free radical damage, 627 function of, 152 genetics and, 210 to hdl ratio, 152, 629 heart disease risk, 152, 175, 175f, 628t, 629 levels, improving, 173, 633 in obese children, 587 oxidation of, 382 plaque formation and, 627 saturated fat and, 157, 175, 175f size and density of, 153f trans-fatty acids and, 157 lead anemia and, 564 in calcium supplements, 436 fetal exposure to, 531 in herbal medicines, 656 malnutrition and, 564 protection against, 565 toxicity, 463, 463t, 560, 563 in water, 401, 553, 565 websites on, 581 lean body mass, 194, 254, 261f, 484 lecithin, 145 146, 146f, 345 lecithinase, 145 legumes, 44 amino acid profile, 195 carbohydrates/fiber in, 125t, 126 diet planning and, 44, 163 length measurements, e-6, e-6f, e-9f, e-10f leptin, 284 285, 285f less-fat (milk), 53 let-down reflex, 533 leukemias, 462, 642 levulose, 103 licensed dietitians, 32 license to practice, 32 life expectancy, 593 body weight and, 263, 264f exercise and, 478 lifestyle and, 594 life span, 593 lifestyle choices chronic disease risk, 25, 210, 586 589, 625, 625f, 629 630 death rates and, 25t environmental considerations, 710 713 food choices, 3 5 genes interacting with, 210 heart disease risk, 629 630, 631 632, 632t hypertension and, 65, 635t life expectancy and, 263, 264f, 594 obesity and, 286 288, 299 302, 567 568, 569, 588 for older adults, 608t pregnancy and, 530 531 sedentary, and health, 266, 287 288, 299 302, 478, 567 568, 587, 588. see also physical activity, benefits of vegetarians and health, 65 light, defined, 58 lignans, 469, 470t, 471, 472f lignin, 106n lima beans, 677 limiting amino acids, 195 limonene, 470t lind, james, 350 lingual lipase, 147 148, 148f linoleic acid, 141 ai for, 160, inside front cover in breast milk and formula, 550 chemistry of, 154, 154f conjugated, 144, 291t, 503, 505 deficiency of, 154 food sources, 141t, 154, 159t structure of, 141f, 141t, 142f, c-3t see also fatty acids, omega-6 linolenic acid, 141 ai for, 160, inside front cover in breast milk and formula, 550 chemistry of, 154, 154f, 154n food sources, 141t, 154, 159t functions of, 154 structure of, 141t, 142f, c-3t see also fatty acids, omega-3 lipases, 77 gastric, 80n, 148f, 149 hormone-sensitive, 156 intestinal, 148f, 149 lingual, 147 148, 148f lipoprotein (lpl), 155, 282 283 pancreatic, 87, 148f, 149 lipectomy, 293 lipids, 139 see also blood lipid profiles; fats index in-19 lipophilic, 147 lipoprotein lipase (lpl), 155, 282 283 lipoproteins, 150 152, 151n, 153f see also blood lipid profiles; cholesterol; chylomicrons; hdl; ldl; vldl liposuction, 293 lipotoxicity, 283 liquid nutritional formulas, 504, 602 listeriosis, 531, 665t, 666 lite, defined, 58 liver (body), 73f, 78, 85f absorbed nutrients in, 83 84, 84f, 85f alcohol and, 240 242, 246t amino acid metabolism, 194 bile and, 78, 149, 151f blood glucose regulation, 112, 113, 114, 114f cholesterol synthesis, 122, 147 cirrhosis, 239, 241 fatty, 198, 239, 240, 241 glucose and, 105n, 107, 110f, 112, 221, 487 glycogen storage and use, 105n, 112, 114f iron storage and recycling, 445, 445f lactate acid, 220f, 221, 487 lipids/lipoproteins, 151 metabolic functions of, 215t protective functions, 84 urea and, 226, 226f, 227f vitamin a storage, 370, 372, 376, 376n vitamin d activation, 377, 377f zinc storage, 453f liver cancer, 643, 644t liver disease, 240, 241, 246t, 657t, 665t liver (food), 376 longevity, 593 597 see also life expectancy low birthweight (lbw), 515, 516, 525 526, 530 low-carbohydrate diets. -see diets, low- carbohydrate low-density lipoprotein. -see ldl low-fat diets. -see diets, low-fat low-fat foods, 296, 298 low-risk pregnancy, 525 lpl. -see lipoprotein lipase lumen, 72 lung cancer, 580, 644t lungs acid-base balance and, 407 exercise and, 478 free radicals and, b-8 functions of, 83, 84f, 483f vascular system and, 84f lutein, 370n, 469, 471, 472f luteinizing hormone (lh), a-4 luteinizing hormone-releasing hormone (lh-rh), a-4 lycopene, 370n, 469, 470, 470t, 472f lymph, 83, 85 lymphatic system, 82, 82f, 83, 84 85, 149 lymphocytes, 622 623 lymphomas, 642 lymph tissues, 623t lysine, 196f, 203 lysosomes, 372, a-2, a-3f lysyl oxidase, 458n m macrobiotic diets, 64, 67, 653, 656t macrocytic (megaloblastic) anemia, 341 macrominerals, 408 see also minerals, major macronutrients, 7 see also specific nutrients macrophages, 622, 627 macrosomia, 516 macula, 605 macular degeneration, 605 in-20 index mad cow disease, 668 magnesium, 423 425 overview of, 425t, 426t absorption of, 409 deficiency, 424, 425t food sources, 424, 425f, 425t functions of, 424, 425t, 436 intake recommendations, 424, 424t, 425f phosphorus and, 409 toxicity, 424, 425t ma huang, 290, 291t, 658 malignant, 642, 643f malnutrition, 20, 197 199 alcohol and, 243 244, 246t causes of, 197 198, 705 706 in children, 197 199, 557, 562 564, 563t, 705, 707, e-7 cocaine and, 579 in eating disorders, 273, 275 fertility and, 509, 526 527 immune system and, 623, 623f, 623t in infants, 557 infectious disease and, 197, 198 199, 453 454, 707 kwashiorkor, 197t, 198 lead contamination and, 564 marasmus, 197, 197t in older adults, 600 pregnancy/fetal development and, 509, 515, 526 527 protein-energy. -see protein-energy malnutrition (pem) recovering from, 199 risk factors in older adults, 609t symptoms/signs, 20, 197t, 563t, e-17t types of, 197, 197t vitamin a deficiency and, 373 374 websites on, 204 world hunger, 705 707, 706f zinc and, 453 454 see also deficiencies; eating disorders; hunger, chronic/world; nutrition assessment; nutrition status maltase, 108 maltitol, 132, 136t maltose, 104, 104f, c-1f mammary glands, 533 manganese, 442, 459 460, 460t, 464t mannitol, 132, 136t mannose, c-2f marasmus, 197, 197t, 198f see also protein-energy malnutrition (pem) marasmus-kwashiorkor mix, 198 margarine butter vs., 157, 166f, 471 as functional food, 471, 472 heart health and, 633 to lower cholesterol, 164, 164n phytosterol source, 472n, 633 trans-fatty acids, 157 margin of safety (additives), 683 marijuana, 579, 654 massage therapy, 653, 656t mastication, 72 matrix, 190 matter, b-1 to b-3, b-2t mayo clinic website, 26 meal planning. -see diet planning meals on wheels, 609 mean corpuscular volume (mcv), e-20t, e-22 measles, 199, 372 373 measurements anthropometric. -see anthropometric measurements glossary of nutrient measures, inside back cover growth charts, 548f, e-8f to e-13f household, 55t of kcalories (kcal), 7 9, 250 251, 250f, 251n metric, inside back cover metric units, 8, 55t meat alternates/substitutes, 41t, 43f, 44, 53, 66, 126 see also soy products meat replacements, 64, 66 meats bovine growth hormone (bgh), 686 687 buffalo, 719 in canadian food groups, i-4f cancer and, 65, 160, 392, 644, 644n, 646t cholesterol in, 158f cooking: low-fat tips, 53 cooking/handling safely, 644, 668, 669f, 670, 671t dioxins, 686 discretionary kcalories and, 45 in exchange lists, 47, g-1t, g-3t, g-8t, i-10t to i-11t farming and, 716, 717f, 718, 719, 719f fat and heart disease, 65, 175 fat in, 53, 157, 157f, 162, 162f, 163, g-8t in food group plans, 41t, 43f, 46t, 47f, 48t, 49f free-range, 162, 177 heart disease and, 65, 175, 319 as iron source, 444, 444f, 450, 450f limiting consumption of, 201 202 in low-fat diets, 53, 162, 162f, 163 mad cow disease, 668 niacin in, 332, 334f nitrosamines in, 684 nutrients in, 43f, 53 pbb contamination of, 676 portion sizes, 53 protein in, 195, 201, 202 range-fed beef, 718, 719 saving money on, 704 serving sizes, 43, 201 thiamin in, 329f medical exams. -see physical examinations medical terms, gl-1 to gl-18 medical tests. -see laboratory tests medications absorption and, 616, 616t for acne, 374 alcohol and, 242 anticoagulants, 354 aspirin, 341, 615, 616 for bulimia nervosa, 276 caffeine in, h-1t for cholesterol (blood), 589 diuretics. -see diuretics drug excretion, 616t, 618 drug history, e-2t, e-3 genetic engineering of, 695 heartburn and, 96 97 herbal. -see herbal medicines/supplements herb-drug interactions, 657 658, 658t for hypertension, 636 637 lactation and, 537 lactose in, 111, 618 laxatives, 96 marijuana as, 654 metabolism and, 616, 616t metabolism of, 242 methotrexate, 617, 617f nutrient absorption and, 616, 616t nutrient excretion and, 616t, 617 618 nutrient interactions with. -see nutrient-drug interactions for obesity treatment, 290, 291t, 292, 616 older adults use of, 615 for osteoporosis, 434, 434n peptic ulcer and, 97 pharmacological effects of vitamins, 332, 360 pregnancy and, 530 single amino acid supplements as, 203 sodium in, 618 sorbitol in, 618 sugar in, 618 vitamin b6 and, 336 vitamin k and, 384 vs. functional foods, 473 see also specific medications meditation, 653 mediterranean diet composition of, 177 food groups, 46t health and, 177 heart disease and, 13f, 173, 177, 471 oxidative stress and, 597 phytochemicals and, 471 megaloblastic anemia, 341 megestrol acetate, 615 melanin, 194 melanomas, 642 memory loss, 606 607 men fathers, 545 fertility of, 509, 545, 676 prostate cancer, 160, 644t see also gender differences menadione, 385, c-9f see also vitamin k menaquinone. -see vitamin k menkes disease, 459 menopause, 434, 434f, 435 menstruation/menstrual period amenorrhea, 270, 271, 271f, 273, 434, 537 iron and, 360, 445n, 446, 492, 577 mental health. -see brain; psychological problems mental retardation. -see retardation meos (microsomal ethanol-oxidizing system), 239, 242 mercury contamination, 159, 174, 531, 675 676, 675f meridia, 292n messenger rna, protein synthesis and, 187, 188f, 208 metabolic alkalosis, 413n metabolic rate, basal. -see basal metabolic rate (bmr) metabolic rate, resting (rmr), 254 metabolic syndrome, 265 266, 630 metabolic-type diets, 317t metabolism, 10, 213 236 in adipose tissue, 155 156 of alcohol, 240 242, 240f, 241f of amino acids/proteins, 192, 193 194, 215f, 241, c-11 to c-13f anabolism and catabolism, 214, 215f, 216 basal, 254, 254f, 255t basic chemical reactions, 214 217, 215f of carbohydrates, 115 116, 219 222, 219f 222f diabetes, consequences of, 639, 639f fad diet claims, 316, 319 of fats. -see fat metabolism of glucose in diabetes, 639, 639f inflammation and, 265 liver s function in, 215t low-carbohydrate diets and, 319 manganese and, 459 medications and, 616 617, 616t oxygen in, 221 zinc, 452 453, 453f see also basal metabolic rate; energy metabolism metalloenzymes, 452, 452n, 462 metallothionein, 452, 453f metastasize, 642, 643f methamphetamines, 579 methane, b-3 methanol, 134 methionine, 196f, 343, 343n, 345, 425 methotrexate, 617, 617f methoxatin, 346 methylcobalamin, 342 methylmercury, 675 676, 675f metric measurement units, 8, 55t, inside back cover mexican cuisine, 46t mfp factor, 444, 450 micelles, 149, 152f microangiopathies, 640 microarray technology, 207, 208 microcytic anemia, 337n, 355n microcytic hypochromic anemia, 446 microflora, 86 microminerals. -see minerals, trace micronutrients, 7 microsomal ethanol-oxidizing system (meos), 239, 242 microvillus/microvilli, 80, 82f microwave cooking, 344 345, 686 middle east, zinc deficiency in, 453, 453f milk, low-fat, 53, 554 milk, no-fat, 53 milk, nonfat, 53, 155, 554 milk, reduced fat, 53 milk, skim, 53 milk, soy, 53, 65 milk, zero-fat, 53 milk and milk products alternatives to, 53, 65, 197 bovine growth hormone (bgh), 686 687 calcium, 416, 418 419, 419f, 420 in canadian food groups, i-4f carbohydrate content of, 126 cheese, 47, 111, 126 for children/teens, 562f, 573t, 577 cholesterol in, 158f dental health and, 119 discretionary kcalories and, 45 in exchange lists, 47, g-1t, g-3t, g-5t, i-9t fat, trans, 143n fat intake and, 53, 157f, 162, 163, 175 folate and, 341 fortification of, 53, 330 glycemic index of, 116f goat s milk, 341, 553 heart disease and, 633 for infants, 554, 557, 557f. -see also breast milk; infant formulas intake recommendations, 418 419, 420, 523 kefir, 111 lactose intolerance and, 110 111 in low-fat diets, 162, 163 nutrient density, 38 nutrients in, 43f, 53, 330 for older adults, 603 protein content, 201 202 riboflavin in, 330, 331f safety, 671 ultrahigh temperature (uht) treatment, 610 in usda food guide, 41t, 43f, 45, 46t, 47f, 48t, 49f in vegetarian diets, 65 vitamin a fortification, 375, 375n vitamin d fortification, 330, 330n, 379, 379n, 418 websites on, 427, 581 weight control and, 416 milk anemia, 557 milk sugar. -see lactose milliequivalents (meq), 403 mind-body therapies, 656t mineralization, 416 mineral oil, 94, 95 minerals, 10, 408 427 overview of, 408 410, 409f, 426t, 464t absorption and fiber, 107, 124 absorption and phytates, 107, 409 absorption of, 79f, 363, 409. see also iron absorption adolescent needs, 576 577 alcohol use and, 243 as alternative medicines, 655 assessment tests, e-18t bioavailability of, 363, 409 body composition, 7t, 404t, 409f, b-4t chemistry of, 408 for children, 560 cooking/food preparation, 10, 408, 450 451 evaluating foods for, 329 for exercise, 491 493 fluids and electrolyte balance, 402 406, 404f, 404t, 405f functions of, 10 infant needs, 549, 549f listed, 10n, 402, 409f nutrient-drug interactions, 616, 617 nutrient interactions, 409 for older adults, 603 during pregnancy/lactation, 521f, 522, 523, 531, 535 rda and ai for, inside front cover recommendations: establishing dri, 18f supplements, 360, 362t, 363, 365f tolerable upper intake level, 362t, inside front cover transport of, 409 in water, 400 401, 420, 424, 688 websites on, 365, 427, 465 in whole grains, 51f see also electrolytes; nutrient interactions; specific minerals minerals, major, 408 427 overview of, 408 410, 426t body composition, 404t, 409f listed, 10n, 402 see also specific minerals minerals, trace, 441 465 overview of, 441 442, 464t body composition, 409f, b-4t deficiencies, 441, 442, 464t food sources, 441, 464t listed, 10n nutrient interactions, 442 supplements of, 442, 442n toxicity, 441 442, 464t websites on, 465 see also specific minerals mineral tablets. -see supplements mineral water, 400, 420, 424 misinformation, 32 index in-21 monoamine oxidase (mao) inhibitors, 617, 618t monoglycerides, 147, 151f monosaccharides, 102 absorption of, 108 109, 110f chemistry of, 102 103, 104f in hemicelluloses, c-2f to c-3f structure of, 102f 103f, c-1f, c-2f monosodium glutamate (msg), 685 monoterpenes, 470t, 472f monounsaturated fats, 141 in exchange lists, g-9t food sources, 141t, 144f, 158, 176t heart disease risk, 65, 158, 173, 633 monounsaturated fatty acids (mufa), 141 mortality. -see death; life expectancy motility, 74, 88, 94 mouth, 72 b vitamin deficiency, 330n, 333n, 349f cancer of, 644t carbohydrate digestion, 79f, 108, 109f chewing, 599 600 digestive functions, 72 73, 73f, 74, 76f fat digestion, 147 148, 148f fiber digestion, 79f protein digestion, 186f see also dental caries; teeth msg symptom complex, 685 mucilages, 106n mucosal ferritin, 443, 443f mucosal transferrin, 443, 443, 443f, 444 mucosa/mucosal, 443 mucous, 373 mucous membranes, 78, 371, 373f mucus, 77, 78 muscle conditioning cardiorespiratory training and, 482, 483f hypertrophy/atrophy, 481 protein remodeling, 490 training, 480 weight training, 480t, 484 muscle dysmorphia, 270, 272 muscle endurance, 480, 480, 481 muscles/muscular system atrophy, 481 body composition, 261f creatine and, 504 505 digestion and, 74 76, 75f, 76f energy/fuel for, 484 489, 485t, 486f, 490, 491 energy metabolism, 220f, 221, 482 exercise and, 221, 482, 485 488, 490 exercise for weight gain, 308 fasting/starvation and, 234 235 glycogen and, 105n, 112, 485 488 intestinal, 82f myoglobin, 443 potassium and, 414 protein intake and, 202 of stomach, 75, 75f vitamin e and, 382 see also body composition; weight training see also information on nutrition, validity of; muscle strength, 480 myths miss america, 258f mitochondria, 220, a-2 in cell structure, a-3f exercise and, 221, 488, 489 functions of, 214f, 220, 229f, a-2 oxidation of fatty acids, 222n structure of, 214f moderate exercise, 481 moderation (alcohol), 238 240, 239 moderation (dietary), 39 molasses, 118, 118t mole, b-6n molecules, b-1 molybdenum, 462, 462t, 464t chromium picolinate and, 461 older adults and, 484, 595 596 training and, 184, 480, 481 muscular dystrophy, 382 mushrooms, 677 mutations, 207, 209 see also genetic disorders mycoprotein, 471, 471n myocardial infarction, 626 see also heart attacks myoglobin, 443 mypyramid, 47, 47f, 66f myths about alcohol, 245, 246t about amino acid supplements, 185 in-22 index myths, continued cellulite, 291 food combining, 81 82 about lecithin, 145 146 spot reducing, 301 302, 489 vitamin impostors, 346 about weight loss, 315 320, 316t see also information on nutrition, validity of; neutrophils, 622 news media, 30 31 nhanes (national health and nutrition examination survey), 22n, 26 niacin, 331 333, 356t overview of, 333t cooking and, 332 deficiency, 331 332, 332f, 332n, 333n, quackery/quacks 333t, 348 n nadh, 239, 241, c-6f, c-11 to c-15, c-13f, c-16f nad (nicotinamide adenine dinucleotide), 239, c-6f in alcohol metabolism, 241, 241f, c-15 function of, 331 tca cycle and vitamins, 347 348, 347f tca cycle reactions, c-12f, c-12 to c-14, c- 13f, c-15t nadp, 331, c-6f naphthoquinone. -see vitamin k narcotic, alcohol as, 239, 242 national health and nutrition examination survey (nhanes), 22n, 26 national library of medicine, 31f national nutrition monitoring program, 22 23 natural vs. safe, 34f, 349, 656 natural water, 400 naturopathic medicine, 653 nausea during pregnancy, 524 525, 524t negative correlation (research), 14, 15 negative feedback, a-4 neotame, 132, 133t, 134 nephrons, 402f nerves/nervous system alcohol and, 242 243 in alzheimer s disease, 607 central nervous system, a-7 to a-8, a-8f in diabetes, 640 diagram of, a-8f energy source for, 112, 234, 235 functions of, a-7 to a-8 gi hormones and, 86 88 lead toxicity and, 463, 564 magnesium deficiency, 424 neural tube, 338 neural tube development, 512 515, 513f. -see also neural tube defects potassium and, 414 thiamin and, 327 vitamin b12, 341, 344 vitamin b6 and, 336 vitamin e and, 382 see also brain net protein utilization (npu), d-1 neural tube, 338, 513f neural tube defects, 338, 513 515 anencephaly, 513 critical periods, 512, 512f, 513 515 folate and, 338, 340, 340f incidence of, 513n maternal obesity and, 516 spina bifida, 340f, 341f, 513, 514f websites on, 357, 539 neurofibrillary tangles, 607 neurons, 606 neuropeptide y, 253 neurotransmitters, 194 acetylcholine, 345, 606 epinephrine. -see epinephrine norepinephrine, 194 serotonin. -see serotonin synthesis of, 194, 606 tyrosine and, 194 vitamin c and, 352 food sources, 332, 333t, 334f functions of, 220, 331, 333t precursor of, 194 rda/recommendations, 331, 333t, 334f structure of, c-6f toxicity, 332, 333t tryptophan, 194, 331, 332, 336 niacin equivalents (ne), 331, 333 niacin flush, 332 nickel, 462 nicotinamide. -see niacin nicotinamide adenine dinucleotide. -see nad nicotinic acid. -see niacin night blindness, 373, 373f see also vision nitrites, 684 nitrogen atomic structure, b-3 in organic compounds, b-3 in proteins, 193n protein utilization and, d-2 urea and, 226, 226f, c-15 to c-16, c-16f nitrogen balance, 193 194 nitrosamines, 684 non-b vitamins, 345 346 nonnutrients. -see phytochemicals nonnutritive sweeteners, 132 see also artificial sweeteners nonpoint water pollution, 716, 717 nonstarch polysaccharides, 106 noradrenalin. -see norepinephrine norepinephrine, 194, 617, a-5 npu (net protein utilization), d-1 nucleotide bases, 207, 208 nucleotides, 207, 208 nucleus, 208f, 214f, a-2, a-3f nursing bottle tooth decay, 553, 554f nutraceuticals. -see functional foods nutrient additives, 685 nutrient claims (on labels), 57 nutrient density, 38 39 comparing foods, 38 evaluating foods for, 329 exercise, diets and, 497 food labels and, 55 of fruits, 39, 119 for older adults, 602 of snack foods, 39 of sugary foods, 118t, 119 usda food guide and, 42f 43f, 45 of vegetables, 329, 330 weight management and, 39, 45 see also energy density nutrient-drug interactions, 615 618, 616t anticoagulants and vitamin k, 384, 617 fat-soluble vitamins and mineral oil, 95 folate and, 341, 617, 617f grapefruit juice and, 617, 617t metabolism and, 616 617 minerals and antibiotics, 616 tyramine and mao inhibitors, 617, 618t nutrient-gene interactions. -see genomics, nutritional nutrient interactions overview of, 463 464 beta-carotene and vitamin e, 363 b vitamins, 340, 341, 346 calcium, potassium, sodium, 411 calcium and iron, 436 calcium and magnesium, 424 calcium and manganese, 459 calcium and protein, 418 calcium and sodium, 409, 411, 418 calcium and vitamin d, 378, 417f, 418, 434, 436 copper and vitamin c, 442 copper and zinc, 453, 459 fat-soluble vitamins, 386 fiber and minerals, 124, 444 folate and vitamin b12, 340, 341, 342 344, 344f, 514 iodine and selenium, 442 iron and manganese, 442, 459 iron and vitamin c, 66, 351, 354, 444, 448, 556 iron and zinc, 453, 522 magnesium and phosphorus, 409 minerals (overview), 409, 442 riboflavin and vitamin b6, 346 soy and zinc, 66 supplements and, 363 vitamin a and zinc, 453 vitamin e and vitamin k, 363, 382 see also nutrient-drug interactions nutrient measures (glossary of), inside back cover nutrients, 6 chemistry of, 5 11, c-1 to c-17 classes of, 7t conditionally essential, 156, 345 energy-yielding, 7 10, 7t, 9t, 18, 215f, 216, 217 218, 227 essential, 7, 154 155, 195, 397 indispensable, 7 interdependence of, 89 macro- vs. micronutrients, 7 naive vs. accurate view of needs, 18f physiological vs. pharmacological effects of, 332, 360 recommendations. -see dri; rda see also specific nutrients nutrigenetics, 11, 207 nutrigenomics, 11, 207 nutrition, 3 food choices and, 5 healthy people 2010 goals, 23, 23t, j-1t to j-2t national trends in, 23 recommendations. -see dri; rda research methods, 11 16 websites/resources, 26, 33, 34 see also dietitians; information on nutrition, validity of nutritional genomics. -see genomics, nutritional nutrition assessment, 20 24, e-1 to e-23 anthropometrics overview, 21, e-5 to e-6, e-5t biochemical analyses. -see laboratory tests cautions, e-22 to e-23 data analysis, e-4 to e-5 fat vs. lean tissue, 262 263, 264f, e-14 to e-16, e-16t growth/growth charts, 548f, e-6 to e-7, e-6f to e-13f healthy people 2010 goals, 23, 23t historical information, 20 21, 22f, 287, e-1 to e-5, e-2t of individuals, 20 22, 21f iron deficiency, 22, 446 physical examinations, 21, 22f, e-16, e-17t of populations, 22 24 protein-energy malnutrition, e-17t, e-17 to e-19, e-19t, e-22t nutrition facts, 55 56, g-2f nutritionists, 32 nutrition screening, e-1 to e-23 nutrition status medications and, 615 618, 616t national surveys, 22 23, 22n of older adults, 598 601, 615 risk factors, e-2t supplements and, 360 361 vitamins and minerals, e-18t see also deficiencies; nutrition assessment nutrition support. -see diet therapy nutritive sweeteners, 132, 136, 136t nuts, 43f, 126, 173 174, 393, 566 o obesity, 281 310 in adolescence, 115, 120, 576 alcohol and, 243, 246t animal studies on, 13f, 285f bmi and, 260f bmr and, 254 body composition and, 262 263, 262f, 263f calcium and, 416 cancer risk, 266, 643, 646t causes of, 283 288 central obesity, 243, 262 263, 262f, 263f, 265, 301 302, 630 in children, 115, 120, 567 571, 567f, 568f, 586 cholesterol, blood levels, 587, 588 as chronic disease, 292 clinically severe, 292 diabetes and, 115, 265, 586, 638 environmental influences on, 302 303 exercise and, 287 288, 299 302, 569 fast food/restaurant portions, 287 fat and energy intake, 160, 315 316 fat cell number and, 282, 283f genetic basis of, 284 285, 316t health risks overview, 263 266, 288 289, 625f heart disease risk, 265, 629, 630 hunger/poverty and, 702 703 hyperplastic/hypertrophic, 283 hypertension and, 265, 635 lifestyle choices and, 285 287, 299 303 lipoprotein lipase (lpl) and, 282 283 mortality rates, 264f, 265 in older adults, 598 overeating and, 285 286 overnutrition and, 20 during pregnancy, 516 prevention of, 569 570 psychological/social factors, 289, 289f smoking and, 262, 264 statistics on, 281, 282f sugar and, 120 types of, 262f, 263f, 283 websites on, 309 see also obesity treatment; overweight; weight loss; weight management obesity gene, 283, 285f obesity treatment, 294 305 aggressive treatments, 292 293, 293f behavior modification, 571 for children, 569 571 dangers of, 289 291, 291t drugs, 290, 291t, 292, 616 exercise, 299 302 expectations and goals, 294 295, 294f herbal products, 291t safe rate of weight loss, 295 strategies, successful, 294 298, 295t, 296t, 297f, 299t support groups, 304 surgery, 286, 292 293, 293f websites on, 309 see also diet planning; diets; weight loss; weight management ob gene, 283, 285f obligatory water excretion, 399 ob protein, 284 oils, 139 heart health and, 633 saturation, degree of, 142, 144f, 164 tropical, 142, 144f, 175, 633 in usda food guide, 41t, 44, 47f see also fats; fish oils; monounsaturated fats; polyunsaturated fats older adults. -see aging (older adults) oldways preservation and exchange trust, 61, 67 olean. -see olestra oleic acid, 141t, 145f olestra, 93, 164 165 oligosaccharides, 105 olive oil, 144f, 158, 173 omega, defined, 141 omega-3 fatty acids. -see fatty acids, omega-3 omega-6 fatty acids. -see fatty acids, omega-6 omnivores, 64 opsin, 192, 371, 371f oral rehydration therapy (ort), 406, 707 organelles, a-2 organic, 7, 58, 680 organically grown crops, 7, 680, 681f, 691 organic halogen, 675 organic nutrients, 7, 7t organosulfur compounds, 470t orlistat, 292 ornish diet, 317t ornithine, 182n orotic acid, 346 orthomolecular medicine, 653 osmosis, 405, 405f osmotic pressure, 405 osteoarthritis, 605 osteoblasts, 372, 417f osteoclasts, 372, 377n, 417f osteomalacia, 378, 381t, 522 osteopenia, 434f osteoporosis, 421, 431 437 age and bone mass, 433 434, 433f, 434f, 603 in athletes, 271, 271f body weight and, 264, 435 calcium and, 200, 361, 411, 421, 433 434, 435 436 eating disorders and, 271 estrogen replacement therapy, 434 exercise and, 435, 478 gender and, 434 435, 436 height loss, 433f hip fractures, 431, 433, 436 hormones and, 434 435, 434n potassium and, 411 proteins (dietary) and, 200 risk factors, 432 433, 433t sodium and, 411 therapy for, 361, 434, 434n type i, 431, 432, 433t type ii, 431, 432, 433t types of bone, 431 432, 432f vitamin a and, 374 vitamin d and, 378, 434, 436 websites on, 437 ovarian cancer, 644t overeating binge eating, 270, 274, 275f, 276, 277t cognitive influences, 251 compulsive, 276 energy metabolism and, 232 233, 234f factors affecting, 251 252, 252f, 253f, 302 303 obesity due to, 287, 304 overfat vs. overweight, 258, 259 overload principle, 480 481 index in-23 overnutrition, 20 see also feasting; obesity overpopulation, 707 709 overt, defined, 22 overweight, 259, 281 310 arthritis and, 605 bmi and, 260f breastfeeding and, 552 cataracts and, 605 causes of, 283 288 in children, 558, 567 571, 567f, 568f, e-7 cholesterol, blood levels, 588 fertility and, 509 fitness and, 266, 288 289 health risks overview, 265 266 healthy people 2010 goals, 23t older adults, 598 during pregnancy, 516, 517f, 517t prevalence of, 282f, 282 salt sensitivity, 410 vs. overfat, 258, 259 websites on, 309 see also obesity; weight gain; weight loss ovum, 510, 511f oxalate/oxalic acid, 409 calcium absorption, 418 iron absorption, 444 kidney stones, 354n, 355n mineral absorption, 409 oxaloacetate, 227, 228f oxidants, 390, 391 see also antioxidants; prooxidants oxidation (of energy nutrients), 223 oxidation (of fats), 143, 222 carbohydrate intake and, 228n carnitine and, 346 exercise and, 489 fatty acid metabolism, 222 223, 223f, 231f genetics and, 210 in mitochondria, 222n rancidity, 143 reaction sequence, c-11, c-11f vitamin e and, 382, 383 see also ketone bodies oxidation-reduction reactions, 442, b-7f, b-7 to b-8 oxidative burst, 352, 390 oxidative stress, 351, 390 aging process and, 597, 606 607 cataracts and, 605 diet and, 597 effects of, 391 exercise and, 492 iron and, 448 vegetable intake and, 598 vitamin c and, 351, 353 vitamin e, 492 see also antioxidants; free radicals oxygen atomic structure of, b-3 circulatory system and exercise, 482, 483f energy metabolism and, 229, 486 free radicals, 390, 390n, 391 in glucose metabolism, 221 lead toxicity and, 463 molecular structure of, b-4f oxygenated water, 505 vo2 max, 482, 483f see also aerobic activity; hemoglobin oxygen-derived free radicals, 390, 390n, 391 oxytocin, 533, a-5 oysters, 670 oyster shell, 431, 436 ozone therapy, 653 in-24 index p paba (para-aminobenzoic acid), 346 pagophagia, 447 pain, tryptophan and, 203 palm oil, 142, 144f, 157, 175 pancreas, 72, 73f, 74, 515 pancreatic cancer, 341, 644t pancreatic duct, 73f pancreatic enzymes amylase, 108 carbohydrases, 87, 109f functions of, 77, 80t lipases, 87, 148f, 149 protein digestion, 186f secretion of, 87 88, 109f zinc and, 452, 453f pancreatic hormones. -see glucagon; insulin pancreatic juice, 77, 77f, 78 pancreatitis, 88 pangamic acid, 346 pantothenic acid, 335, 335t, 347f, 348, 356t, c-7f para-aminobenzoic acid (paba), 346 paraguay tea, 656 paralytic and neurotoxic shellfish poisoning, 670n parasympathetic (nervous system), a-7 to a-8, a-8f parathormone (pth), 191t, 416, 434, 434n, a-6 parathyroid gland, 416, 417f, a-6 parathyroid hormone, 417, 417f, a-6 pasteurization, 666, 673 pathogens, 664 pbb (polybrominated biphenyl), 676 pcbs (polychlorinated biphenyls), 676 pdcaas (protein-digestibility-corrected amino acid score), d-1 to d-2, d-2t peak bone mass, 418, 421f peanuts, 566 peas. -see legumes pectins, 106n peer review, 14, 15 pellagra, 331, 332f, 332n, 348;p pem. -see protein-energy malnutrition pepsin, 185, 186f pepsinogen, 185 peptic ulcer, 94, 97, 97t peptidase, 185 peptide bond, 183, 183f perfringens food poisoning, 665t peripheral nervous system, a-7 to a-8, a-8f peripheral resistance, 633, 634f peristalsis, 74 75, 75f, 86, 92 93, 95 pernicious anemia, 343, 344f, 514 peroxides, b-8 per (protein efficiency ratio), d-1, d-3 to d-4, d-4t persistence (of contaminants), 674 675 pesticides, 678 681 adverse reactions, 567 cancer risk, 643 effects of, 716 epa hotline for, 680 imported foods and, 678 679 plant-pesticides, 693, 695 sustainable agriculture, 718t tolerance levels, 567 ph, 77 acid-base balance, 406 407, 407f of digestive secretions, 77f explanation of scale, 77f, 407f, b-6 in intestines, 77, 87 ketosis and, 235 in stomach, 77 see also acid-base balance phagocytes, 622 phagocytosis, 622 pharmacological effect of nutrients, 332, 360 pharynx, 72, 73, 73f phenolic acids, 470t phenylalanine, 133 134, 134f, 182f, 183, 209 phenylketonuria (pku), 133 134, 183, 207, 209 phospholipids, 145 146, 146f, 149, 422 see also lecithin phosphoproteins, 422 phosphorus, 422 423 overview of, 423t, 426t absorption of, 409 deficiency, 422, 423t food sources, 422, 423f, 423t functions of, 422, 423t intake recommendations, 422, 423f, 423t magnesium and, 409 toxicity, 423t photosynthesis, 213, b-7 phylloquinone, 385 see also vitamin k physical activity, 477 501 alcohol and, 496 appetite and, 301 basal metabolic rate and, 254, 254f, 255t, 256 body s response to, 481 caffeine and, 496 children, 567 568, 569, 570, 588 discretionary kcalories and, 300, 300f duration, 485, 485t, 487, 489, 490 endurance, 484, 486f, 487, 489 energy (kcal) expenditure, 254, 254f, 255t, 257t, 300, 482, 489 energy (kcal) expenditure: calculating, 257, f-1, f-2 to f-6t energy metabolism: carbohydrates, 221, 485 488, 485t, 486f, 488t energy metabolism: fats, 486f, 489 energy metabolism: proteins, 486f, 490 491, 491t exercise, defined, 477 free radicals and, 492 healthy people 2010 goals, j-2t intensity, 482, 485t, 486, 489, 490 during lactation, 534 535 minerals for, 491 493 moderate exercise, 481 pregnancy and, 509, 518 519, 519f, 529 spot reducing, 301, 489 vitamins for, 491 493 websites on, 499 500, 648 see also aerobic activity; athletes; fitness physical activity, benefits of overview of, 301, 478 480 arthritis and, 605 blood lipids and, 588 body composition and, 300 301 cancer and, 478, 643, 646t constipation and, 94 diabetes and, 638, 641 heart disease risks, 478, 489, 629, 632t hypertension reduction, 636 longevity, 595 596 muscle mass, 599f obesity and, 266, 569, 570 for older adults, 478, 595 596, 596t osteoporosis and, 435, 478, 484 psychological, 301 for weight control, 287 288, 299 302, 305, 484 for weight gain, 308 physical activity guidelines overview of, 479f, 480 484, 480t canadian recommendations, i-7f carbohydrate intake, 486f, 487 488, 497 cardiorespiratory endurance, 480, 482 483, 483f choosing types of, 479, 479f in daily routines, 479f dietary guidelines and, 39, 40t, 479 diet planning for, 496 499, 498f duration, 480, 480t, 483t, 576 fat intake, 489 fluids and electrolytes, 493 497, 494t frequency, 479, 479f, 480, 480t, 483t for heart disease reduction, 632t for hypertension reduction, 635t, 636 intensity, 480, 480t, 482 moderate exercise, 481 for older adults, 596, 596t, 603 progressive overload principle, 480 protein intake, 490 491, 491t, 497 pyramid, 479f safety, 481, 484, 493 495 sample schedule, 483t snacks, 487, 498f warm-up/cool-down, 481 websites on, 581 for weight management, 288, 299 302, 495 weight training, 481, 484 physical examinations, 21, 22f, e-16, e-17t see also laboratory tests physical fitness. -see fitness physicians, nutrition information from, 31 physiological age, 595 physiological fuel value, 250 phytates (phytic acid), 107, 409 calcium absorption, 418 digoxin and, 616 iron absorption, 444, 448 manganese and, 459 minerals and, 107, 409, 470t yeast and, 453n zinc and, 452 phytochemicals, 6, 469 471 as antioxidants, 391, 469 470, 470t, 471 cancer and, 469 470, 470t, 645, 655 carotene. -see beta-carotene; carotenoids disease prevention, 469 471, 470t, 472f effects of, 470t food sources, 158, 469 471, 470t, 472f in green tea, 655 heart disease and, 471, 472f macular degeneration and, 472f in nuts, 173 osteoporosis and, 434 types of, 470t, 472f see also functional foods phytoestrogens, 434, 469, 470t, 472f phytosterols, 469, 471, 472, 472f, 633 pica, 447, 525, 564 picolinate, 503 pigeon breast, 381n pigment, 371 pituitary gland, 403f, a-3 to a-4, a-4f pku (phenylketonuria), 133 134, 183, 207, 209 placebo effect, 12, 14, 653 placebos, 12 13, 14, 352 placenta, 510, 511f plant foods cancer risk and, 123, 643, 644t, 646t fats and health, 65, 144f, 157 in food group plans, 41t, 42f 43f, 44, 44t protein and bone health, 200 protein and heart disease, 199 protein quality, 195 vs. animal foods: sustainable agriculture, 717, 717f, 718 719, 718t, 719f see also fruits; grains; legumes; nuts; phytochemicals; vegetables plant-pesticides, 693, 695 plant sterols, 470t see also phytosterols plaque, dental, 119 plaques, atheromatous, 626, 627, 629 plaques, fibrous, 586 587, 587f see also atherosclerosis plaques, senile, 607 plasma, e-17 platelets, 627 plp (pyridoxal phosphate), 336, 347f, 348 see also vitamin b6 point of unsaturation, 141 poisoning. -see foodborne illnesses; lead; toxicity; specific toxins polar, 403 polar bear liver, 376 pollution. -see contaminants; environmental contaminants polybrominated biphenyl (pbb), 676 polychlorinated biphenyls (pcbs), 676 polyglutamate, 338, 339f polyols, 132 polypeptide, 183 polysaccharides, 105 107 nonstarch, 106 structure of, 106f, c-2f to c-3f see also glycogen; starch polyunsaturated fats, 141 in exchange lists, g-9t food sources, 141t, 144f, 158, 173, 174, 176f, 176t free radicals and, 390, 391f genetics and, 210 heart disease and, 158, 392 ldl cholesterol and, 210 in range fed beef, 162, 719 replacing saturated fats, 162, 162f, 163, 164, 164t, 166f structure, 141 142, 141f 144f, 141t, c-3t vitamin e and, 382, 383 polyunsaturated fatty acids (pufa), 141 see also fatty acids, omega-3; fatty acids, omega-6 population growth, hunger, environmental degradation, 708f, 709 710 older adults in u.s., 593, 594f world, increase in, 707 709 populations, nutrition assessment of, 22 24 pork, thiamin in, 328f, 329 portal vein, 83, 85f portion sizes. -see serving sizes/portion sizes positive correlation (research), 14, 15 postpartum amenorrhea, 537 post term (infant), 516 potable water, 688 potassium, 414 415 overview of, 415t, 426t deficiency, 414, 415t, 636 637 dietary guidelines and, 40t, 412, 640 diuretics and, 636 637 food sources, 414, 415f functions of, 412, 414, 415t, 436 hypertension and, 414 intake recommendations, 414, 415t osteoporosis and, 411 in processed foods, 412, 412f, 414 sodium-potassium pump, 406 toxicity, 414 415, 415t transport proteins and, 192f potatoes, 116, 354, 644 645, 677, 685, 695 poultry, 163, 668, 669, 669f, 670 see also meats poverty. -see food assistance programs; hunger, chronic/world; socioeconomic status prader-willi syndrome, 284, 285 prealbumin. -see transthyretin prebiotics, 86 precursors (vitamin), 324 prediabetes, 637 preeclampsia, 517, 528 pregnancy, 509 545 in adolescence, 529 alcohol use during, 245, 530, 543 545, 543f, 545f body changes during, 519 body composition and, 262 caffeine use during, 532 calcium, 418 critical periods, 512 515, 512f diabetes and, 527 528 drugs (illicit) and, 530 drugs (medications) and, 530 eating disorders and, 273 energy needs, 520, 521f environmental contaminants, 531 exercise and, 509, 518 519, 519f, 529 father s alcohol intake and, 545 fish consumption, 174, 531, 675, 676 folate and, 338, 340, 514 515, 520, 521f foodborne illnesses, 531 healthy people 2010 goals, j-2t herbal supplements and, 657n high-risk, 525 532, 526t hormones, a-6 hypertension and, 528, 528n illness, maternal, and, 509 iodine in, 456 iron, 446, 521f, 522 low-risk, 525 malnutrition and, 526 527 maternal discomfort, alleviating, 524t nutrition before, 509 510, 526 527 nutrition during, 519 525, 521f, 522f, 523f, 524t, inside front cover nutrition-related concerns, 524 525, 524t in older women, 529 530 placental development, 510, 511f smoking/tobacco use, 530 531 supplements during, 374, 514, 520, 521f, 522, 523, 524, 530, 531 532 underweight and, 264 265 vitamin a and, 374 vitamin b12 needs, 520, 521f, 524 websites on, 539, 545 weight gain during, 516 517, 517f, 517t, 518f, 528, 529 zinc needs, 521f, 522 see also birth defects; fertility/infertility; fetal development prehypertension, 626, 628, 628t prejudice and body weight, 289 premature (infant), 516 prenatal alcohol exposure, 543, 544 prepared foods, 4, 175, 177 preservatives, 682 see also additives pressure ulcers, 602 preterm (infant), 516, 525 526, 530, 554 primary amenorrhea, 270 primary deficiency, 22 pritikin program, 317t probiotics, 86 processed foods, 50 calcium, potassium, sodium, 412f fried, and cancer, 644 645 functional foods, 471 473 obesity and, 569 potassium, 412, 412f, 414 prepared foods, 4, 175, 177 salt/sodium in, 411 412, 412f, 456 vitamin e in, 383 progesterone, a-5, a-7 progressive overload principle, 480 index in-25 prolactin, 533, a-4, a-5 prolactin-inhibiting hormone (pih), a-5 proline, 182n promoters (cancer), 642, 643f, 645 proof (alcohol), 238, 239 prooxidants, 354, 374, 390, 393, 448 propionic acid, 108n prostaglandins, 615, 627 prostate cancer, 160, 644t prostate gland, 654f protease inhibitors, 470t proteases, 77, 185, 186f protein deficiency. -see protein-energy malnutrition (pem) protein digestibility-corrected amino acid score (pdcaas), d-1 to d-2, d-2t protein efficiency ratio (per), d-1, d-3 to d-4, d-4t protein-energy malnutrition (pem), 196 199, 197t, 198f acute, 197 in anorexia nervosa, 273 assessment of, e-17 to e-19, e-17t, e-19t chronic, 197 immune system and, 623, 623t indicators of, 273n kwashiorkor, 197t, 198, 199f marasmus, 197, 197t, 198f websites for, 204 see also malnutrition protein-kcalorie malnutrition (pcm). -see protein-energy malnutrition (pem) proteins, defined, 181 proteins (body), 187 194 alcohol s effect on, 241 building muscles, 202 endogenous, defined, 193 exercise and, 490 491 fasting/low-kcal diets, 201, 234 235, 234f fluid balance and, 405 406 free radicals and, 391f functions of, 10, 184, 189 193, 190f, 191t, 192f gene expression and, 189, 207, 208 glycoproteins, 112 low-carbohydrate diets and, 319 metabolism overview, 192, 193 194 nitrogen balance, 193 phospholipids in, 422 sulfur and, 425, 427 vitamin a and, 372 proteins (chemistry), 181 185 amino acids in, 182t, c-4f denaturation, 184 185 elements in, 7t estimation/measurement of, 193n gluconeogenesis, 112, 192, 225, 225f, 334 liver metabolism of, 215t metabolism overview, 193 194, 215f, 241, c-11 to c-13f structure of, 181 185, 183f, 184f synthesis of, 187 189, 188f, 194, 195, 208, 351 352, 371, 490 see also amino acids proteins (dietary), 195 203 amino acid scoring, d-1, d-1t biological value of, d-1, d-2, d-2t bmi and, 318, 319 body s use of, 227t in breast milk, 550, 550f, 554 in breast milk vs. formula, 553f calcium and bones, 436 calcium loss and, 418 in canadian food groups, i-12t to i-11t cancer and, 200 for children, 560 in-26 index proteins (dietary), continued pyramids complementary, 195 196, 196f daily values, 196, 197n deficiencies, 196 digestibility of, 195 digestion of, 77, 79f, 80t, 88, 185, 186f energy (kcal) in, 9t, 10, 230 in exchange lists, 47, g-1t, g-3t, g-8t for exercise, 491, 491t, 497 exogenous, defined, 193 fat made from, 232 fats (dietary) and, 319 health effects of, 199 200 heart disease and, 199 200, 319 high-protein diets. -see diets, high-protein high-quality, 195 hunger and, 252 for infant growth, 201, 548 549 intestinal motility and, 88 labeling regulations, 196 net protein utilization (npu), d-1 niacin and, 332 nitrogen balance, 193 for older adults, 602 osteoporosis and, 200 overconsumption of, 199, 201 202, 319 overeating and, 232, 234f plant vs. animal sources, 65, 157, 195, 199, 200 during pregnancy/lactation, 520, 521f protein digestibility-corrected amino acid score (pdcaas), d-1 to d-2, d-2t protein efficiency ratio (per), d-1, d-3 to d-4, d-4t quality of, 194 196, d-1t, d-1 to d-4, d-2t, d-4t rda/intake recommendations, 18, 201 202 reference protein (standard), 195 supplements, 202 203, 202n, 520 textured vegetable protein, 53, 64, 66 thermic effect of food, 256, 318 usda food guide, 41t, 43f, 44 in vegetarian diets, 66, 66f, 196 for weight loss, 295t see also amino acids; protein-energy malnutrition (pem) protein-sparing action, 112, 194 protein turnover, 193 proteomics, 187 prothrombin, 384f protons, b-1 to b-3, b-2t provitamins, 324 prozac (fluoxetine), 276n prune juice, 95 psychological problems alcohol as risk for, 246t from being overweight, 289f, 569 dementia, 606 607, 607t depression, 155, 275, 478, 600, 654f eating disorders and, 272, 274, 275, j-2t exercise and, 478 muscle dysmorphia, 270, 272 in older adults, 600 weight loss and, 301, 304 pth (parathormone), 191t, 416, 434, 434n, a-6 puberty, 576 public health dietitian, 32 public water, 400 pubmed, 30, 31f pufa. -see polyunsaturated fatty acids pulmonary circulation, 84f purging, 274 275, 275f purified water, 400 purines, 606 pyloric sphincter, 72, 73f, 74, 75, 76, 87 children, 561f mypyramid, 47, 47f, 60t, 65 66, 66f physical activity, 479f vegetarian diets, 65, 66f, 67 websites on, 67, 580 see also diet planning pyridoxal, c-6f see also vitamin b6 pyridoxal phosphate (plp), 336, 347f, 348, c-7f see also vitamin b6 pyridoxamine, c-6f see also vitamin b6 pyridoxamine phosphate, c-7f see also vitamin b6 pyridoxine, c-6f see also vitamin b6 pyrroloquinoline quinone, 346 pyruvate (pyruvic acid), 218, 218n amino acid metabolism, 225, 225f, c-11 to c-13f b vitamins and, 347, 347f glucose metabolism, 219 222, 219f 222f glycerol metabolism, 222, 224f supplements, 291t, 504 in tca cycle, 228f, a-2n, c-11 to c-13f pyy, 285 q qi gong, 653 quackery/quacks, 30, 32, 33, 34, 34f fad diets, 315 321 see also fad diets; information on nutrition, validity of; myths quality of life, 594 quorn, 471n r race/ethnicity bone density and, 260 diabetes and, 638 ethnic foods, 4, 46, 46t, 61 lactose intolerance and, 111 obesity and, 576 osteoporosis and, 435 see also african americans/blacks rachitic rosary, 378, 381n rae (retinol activity equivalents), 374 raloxifene, 434n randomization (in research), 12, 14 rbp (retinol-binding protein), 370, e-18, e-19t rda (recommended dietary allowances), 17, inside front cover for assessing dietary intake, 21f for protein, setting of, 201 purpose of, 17, 19 safe vs. toxic nutrient intakes, 18f vs. estimated average requirement (ear), 16 17, 17f see also dri (dietary reference intakes); specific nutrients reactive oxygen species (ros), 390n recommended dietary allowances (rda). -see rda rectum, 72, 73f, 76 red blood cells in anemia, 189, 189f, 344f, 446, 447f erythrocyte hemolysis, 382, 383n erythrocyte protoporphyrin, 446, e-20t, e-21t erythropoietin, a-3, a-6 glucose needs of, 223, 234 iron and, 445 lead toxicity and, 463 life span of, 6, 445 normal, 189f in sports anemia, 493 see also hemoglobin reduction reactions, b-7 reference protein, 195 refined (foods), 50 52, 50f, 51f reflux, 76, 94, 96 97, 96f, 97t registered dietitians (rd), 19, 32 registration, 32 regulations. -see under fda (food and drug administration) relaxin, a-5, a-6 religious dietary traditions, 5 remodeling (bone), 372, 416 renin, 401, 403f, 410n, a-3, a-6 rennin, 693, 694 replication (research), 14, 15 reproductive system, vitamin a and, 372 requirements (for nutrients), 16, inside front cover see also dri; rda research, 11 16 on alternative medicine, 652 654 analysis/interpretation of, 14 15 approaches to, 11 15 on colds (example), 12 15 correlation, 14, 15 evaluating validity of, 15 16, 30 31, 33, 34 hypotheses and theories, 11 12, 12f, 14 journal articles, 31t, 33 on obesity, 285f publishing of, 15 16 pubmed searches, 31t sample size, 13 study designs, 11 15, 12f, 13f, 14t terminology, 11 14 residues (pesticide), 678 resistance training, 480t, 484 resistant starch, 107 resource use, 717 720, 719f restaurants fast food, 159, 376, 578, h-58 to h-77 obesity and, 287, 303 salt/sodium, 456 serving sizes, 54, 303 trans fats in, 159, 177 resting metabolic rate (rmr), 254 resveratrol, 470t, 472f retardation, mental cretinism and iodine deficiency, 456 down syndrome, 340, 530 fetal alcohol syndrome, 530, 543 545 malnutrition and, 706 pku (phenylketonuria), 133, 209 retina, 371, 373 retin-a, 374 retinal, 369 370, 370f, 371, 371f, 373, c-5f retinoic acid, 244, 370 371, 370f, c-5f retinoids, 369 retinol, 369 370, 370f, 372, c-5f retinol activity equivalents (rae), 374 retinol-binding protein (rbp), 370, 452, e-18, e-19t retinyl esters, 369 rheumatoid arthritis, 605 rhodopsin, 371, 371f riboflavin, 328 330, 329 overview of, 330t, 356t deficiency, 329, 330t destruction of, 324 food sources, 329 330, 330t, 331f functions of, 328, 330t rda/recommendations, 329, 330t, 331f in structure of coenzymes, 330f, c-5f vitamin b6 and, 346 ribose, 504 ribosomes, 187, 188f, 214f, a-3, a-3f rice, beriberi and, 327 rice milk/drinks, 197, 557 rickets, 378 bones of skull, 381f described, 378f, 381t osteomalacia, 378, 381t sunshine and, 379 in vegans, 67 vitamin d and, 522 523, 551 risedronate, 434n risk, 663 see also safety risk factors, 24 25 rna polymerase, 452n rna (ribonucleic acid), 187, 188f, 193n, 207, 208 rods (of retina), 371f rough endoplasmic reticulum, a-2, a-3f royal jelly, 504 s saccharin, 132 133, 133t safety, 663 689 alternative therapies and, 652, 655f, 656t 658t of artificial sweeteners, 132 136 choking, 92, 92f, 93f, 572 ergogenic aids, 503 507, 506t exercise and, 481, 484, 493 495 of fat replacers, 165 food additives, 683 of functional foods, 472 473 genetic engineering (gm foods), 693 697, 697t herbal remedies, 652 658, 655f, 657t, 658t herbal weight loss products, 291, 291t margin of safety (additives), 683 natural vs. safe herbs, 656 pesticide exposure, 678 681 public health strategies, 306 307, 306t of supplements, 392 393, 436, 656 659, 656t 658t see also contaminants; foodborne illnesses; quackery/quacks; toxicity salicylates, 655 saliva, 76 77, 78, 109f salivary amylase, 108 salivary glands, 78 carbohydrate digestion, 77, 80t, 108 fat digestion, 80n, 147 148, 148f functions of, 76 77 location of, 76f, 109f protein digestion, 186f salmonella, 664, 665t salts, 403, 404f see also electrolytes salt sensitivity, 410, 410n, 635 salt (table). -see sodium; sodium chloride saponins, 470t sarcomas, 642 sarcopenia, 598, 599f satiating, 251 satiation, 251, 252f, 253f satiety, 108 factors affecting, 251 253, 252f, 253f fat and, 252, 298 fiber and, 108, 252 ghrelin and, 285, 286 leptin and, 284 overriding signals, 251 252 protein and, 252 pyy and, 285 saturated fats, 141 blood cholesterol and, 157, 158, 175, 175f cancer and, 160, 645 chemistry of, 140, c-3t diabetes and, 641 in exchange lists, g-9t food sources, 141t, 144f, 157, 157f, 175, 176t heart disease risk, 65, 157, 158, 173, 175f, 626, 632t, 633 intake, lowering, 162, 162f, 163, 164, 164t, 166f, 167, 176f intake recommendations, 157 on labels, 58 in meats, 162f in milk and milk products, 162f structure of, 140, 141t, c-3t in u.s. diet, 157f vegetarian diets and, 65 saturated fatty acids, 141 saw palmetto, 654f, 657t, 658t school nutrition programs, 573 575, 574t, 702 science of nutrition. -see research scientific method, 11, 12f scombroid poisoning, 670n scurvy, 350, 353, 353f, 354 seafood. -see fish/seafood seaweed, 67 secondary amenorrhea, 270 secondary deficiency, 22 second harvest, 704 secretin, 87, 88t, a-6 sedentary, defined, 477 see also lifestyle choices segmentation (intestinal), 75 76, 75f selective estrogen-receptor modulator (serm), 434n selenium, 457, 464t overview of, 458t deficiency, 457, 458t food sources, 457 458, 458t intake recommendations, 458, 458t iodine and, 442 toxicity, 458, 458t self-image/self-esteem, 276, 289, 301, 478, 569 see also body image senile dementia, 606 senile plaques, 607 senna, 655 serotonin, 120, 290 drug use and, 579 functions of, 194 precursor of, 194 vitamin b6, 336 serum, e-17 serum ferritin, e-20, e-20t, e-21t serum iron, e-21, e-21t serum transferrin, e-20t, e-21t serving sizes/portion sizes in canada s food guide, i-3t to i-6t in canadian food groups, i-8t to i-11t energy intake and, 41t, 44t estimating, 46 in exchange lists, g-1 to g-11, g-1t, g-4t to g-11t fast food, 287 fat and, 252, 253f on labels, 54f, 55 meats/protein, 43f, 53 nutritional assessment and, e-5 overeating and, 303 in restaurants, 54, 303 satiety and, 252 253, 253f usda food guide and, 41, 42f 43f, 44, 46 for weight gain, 308 for weight loss, 296 set-point theory, 283 seven countries study, 173 sex. -see gender differences sex hormones. -see estrogens; progesterone; testosterone shape up america, 266 shigellosis, 665t index in-27 shopping. -see grocery shopping sibutramine, 292 sickle-cell anemia, 189, 189f, 204 sids. -see sudden infant death syndrome silicon, 462 simple carbohydrates. -see under carbohydrates (dietary) skin acne, 374 beta-carotene and, 373f, 374, 375f, 377n epithelial cells, 371 finding cause of problems, 350 keratinization of, 373f, 374 vitamin a and, 373 374 vitamin c and, 353, 353f vitamin d and, 377, 380, 380f skin cancer, 379 380 skin cells, 190 skinfold body fat test, 264f skinfold measures, 264f, e-14f, e-14 to e-15, e-16t sleep, 203, 286, 478 small for gestational age (sga), 526 small intestines, 72 absorptive functions, 79f, 81 83, 81f, 82f, 110f anatomy of, 73f, 74, 74n, 80, 82f bacteria in. -see intestinal bacteria calcium balance and, 417f carbohydrates digestion in, 79f, 108, 109f digestive functions, 75f, 79f, 109f enzymes of, 77, 81, 109f, 186f fat absorption, 149 150, 152f fat digestion, 79f, 148f, 149 motility, 74, 88, 94 muscles of, 75 76, 75f peristalsis, 74 75, 75f, 86 ph of, 87 protein digestion, 79f, 185, 186f smell, sense of, 72 smoking/tobacco use adolescents and, 579 580, 589 antioxidants and, 580 atherosclerosis and, 587 beta-carotene and, 374 body fat and, 262, 264 cancer and, 643, 644t chronic disease risk, 25, 25t deaths from, 25, 25t folate and, 341 heart disease risk, 589, 629, 631 lactation and, 538 nutrient intakes and, 579 osteoporosis and, 435 pregnancy and, 530 531 smokeless tobacco, 580 supplements and cancer risk, 580 vitamin c and, 353 vitamin e and, 383 websites on, 581, 648 smooth endoplasmic reticulum, a-2, a-3f snacks for adolescents, 578 for children, 569, 572, 573t in exchange lists, g-4t for exercise, 487, 498f heart health and, 633 for older adults, 602 portion sizes, 303 for weight gain, 308 social interactions, food choices and, 4, 302, 600, 609 societal attitudes adolescent body weight, 576 athletes body weight, 271 eating disorders and, 272, 276 prejudice and body weight, 289 see also body image in-28 index socioeconomic history, e-2t, e-3 socioeconomic status birthweight and, 526 environmental degradation and, 709 710 hunger and, 702 704, 702f, 705, 707 709 lead poisoning and, 564 malnutrition and, 197, 562 of older adults, 600 overpopulation and, 707 709 see also food assistance programs sodium, 410 413 overview of, 413t, 426t in antacids, 618 atomic structure of, b-5 calcium and potassium, 411, 412f calcium loss and, 418 dash eating plan, 411, 416, 636 deficiency, 412, 413t dietary guidelines and, 40t, 45, 411, 412, 636 food sources, 411 412, 412f, 413t functions of, 410, 413t heart disease and, 633 high-sodium diets, 402 403 hypertension and, 400, 410 411, 635t, 636, 636t hyponatremia, 495 496 intake recommendations, 410, 411, 412f, 413t on labels, 58 losses of, 406, 412 osteoporosis, 411 in processed foods, 411 412, 412f reducing intake, 411 retention/regulation, 401 402, 403f, 406, a-6 salt sensitivity, 410, 410n, 635 in sports drinks, 495 toxicity, 413, 413t transport proteins and, 192f in water, 400 websites on, 427 sodium bicarbonate, 504 sodium chloride in fast foods, 456 intake recommendations, 410, 411 iodine in, 456 ion formation, b-5 salt tablets, 412, 495 sodium content of, 411 see also chloride sodium-potassium pump, 406 soft drinks caffeine content of, 496, 578, h-1t cola beverages, 39, 422, h-1t diet, 135t displacing nutrients, 422 quantities consumed, 568, 578 sugar content of, 117 118, 118t, 120, 568 soft water, 400 401 solanine (in potatoes), 677 soluble fibers, 106 see also fiber solute concentration, 405 solutes, 405 somatic nervous system, a-7, a-8f somatostatin (ghih), a-5 somatotropin (gh), a-5 see also growth hormone (gh) sorbitol, 93, 132, 136t, 618 soup kitchens, 704 south beach diet, 317t soy formulas, 67, 553, 557 soy milk, 53, 65 soy products blood cholesterol and, 65, 162, 471, 472f cancer and, 469 470, 472f heart disease and, 632t osteoporosis and, 434 phytochemicals and, 434, 469 470, 472f precautions, 656t protein quality, 195 textured vegetable protein, 53, 64, 66 tofu, 64, 65, 67n vitamin b12 and, 344 zinc absorption, 66 specific dynamic activity (sda), 256 specific dynamic effect (sde), 256 sperm, 510 sphincters, 72, 73f, 74, 76, 76f spina bifida, 340f, 341f, 513, 514f, 539 see also neural tube defects spirulina, 504 sports. -see athletes sports anemia, 493 sports drinks, 121, 487, 495, 507 spot reducing, 301, 489 spring water, 400 st. john s wort, 290, 654f, 657t, 658, 658t stanol esters, 472n staphylococcus aureus, 665t, 666 starch, 101 in canadian food groups, i-8t to i-9t chemistry/structure of, 105 106, 106f, 107f, c-2, c-2f digestion and absorption, 79f, 108 109, 109f in exchange lists, 48, g-1, g-1t, g-4t food sources, 105 106 glucose and, 105 health effects of, 122 124 on labels, 126 127 recommended intake of, 124 127, 125t resistant, 107 see also carbohydrates starvation bmr and, 255n fat and lean tissue losses, 194, 234 235, 250 ketosis, 156, 235, 235f physical consequences of, 272 273 symptoms of, 236 see also eating disorders; fasting; malnutrition stature-for-age percentiles, e-12f stearic acid, 140, 140f, 141t, 157 sterile, defined, 384 steroids, 146n steroids, anabolic, 503, 505, 506t sterols, 146 147, 146n, 147f, 149, 164 stevia, 132, 136 stomach, 72, 73f atrophic gastritis, 343 carbohydrate digestion, 108, 109f fat digestion, 148 149, 148f function of, 74, 75, 77, 79f gastric juice, 78 gastrin and, 87 hunger sensation and, 251 muscles of, 75, 75f obesity surgery, 292 293, 293f peptic ulcers, 97, 97t ph of, 77, 77f, 87 protein digestion, 77, 79f, 185, 186f stomach cancer, 65, 97, 644t stools, 78 strength training, 302, 480t, 481, 484 stress, 597 aging process and, 597 598 epinephrine and, 114 exercise and, 301 hormonal response to, a-4, a-5 overeating and, 252, 304 supplements and, 364 vitamin c and, 352 see also oxidative stress stress eating, 251 stress fractures, 270, 271 stressors, 597 stress response, 598 strokes, 626 alcohol and, 635 atherosclerosis and, 627 blood cholesterol and, 157 omega-3 fatty acids and, 158 potassium and, 414 websites on, 648 structure-function claims, 59, 60t, 364 studies. -see research subclavian vein, 85 subclinical deficiency, 22 subjects (of research), 12, 14 successful weight-loss maintenance, 305 sucralose, 132, 133t, 134 sucrase, 108 sucrose, 104, 104, c-1f see also sugars sucrose polyester, 164 sudden infant death syndrome (sids), 531, 556n sugar alcohols, 132, 136, 136n, 136t sugar-free (on labels), 58, 136, 137f sugar replacers, 132, 136, 136t sugars, 101 105, 118 absorption of, 79f alternatives to, 132 137, 133t behavior and, 120, 564 in blood. -see blood glucose levels chemistry of, 102 105 dental caries and, 119 diabetes and, 640 641 disaccharides. -see disaccharides discretionary kcalories and, 45 energy (kcal) in, 117 118, 118t, 120, 121 in foods, 121 glycemic index of, 116 health effects of, 117 121 heart disease and, 120 honey vs., 118, 118t, 556 intake guidelines, 121 on labels, 58, 117, 118, 121 monosaccharides. -see monosaccharides obesity and, 120 structure of, 102f 104f, c-1 to c-3f types of (glossary), 118 websites on, 127 see also sweets; specific sugars sugars, added, 117 121, 568 sulfate, 425, 426t, 427 sulfites, 684 sulforaphane, 472f sulfur, 425 sunlight in synthesis of vitamin d, 377, 379 380, 380f superoxide dismutase (sod), 391n, 458n supplements, 360 365 amino acids, 185, 202 203, 202n antioxidants, 390, 392 arguments for and against, 360 363 for arthritis, 606 for athletes, 202, 492, 497, 503 507, 506t average doses, 362t beta-carotene, 363, 374, 580 bioavailability of, 363 breakfast cereals as, 51 b vitamins, toxicity of, 349 caffeine, 503 calcium, 361, 363, 416, 436 carnitine, 346, 503 for children, 373, 560 choline, 346, 607 chromium picolinate, 461, 503, 504 complete nutrition, 504 contaminants in, 206, 436 creatine, 503, 504 505 enzymes, 364 ergogenic aids, 503 507, 506t fad diets and, 319 fiber, 106 107, 123 fish oil, 159, 531 folate, 338, 340, 514 foods vs., 19, 349, 363, 365, 392 393, 471, 604 herbal. -see herbal medicines/supplements high potency, 360, 361, 364 hormonal, 505 506, 506t for infants, 384 385, 551, 551t inositol, 346 iron, 360, 361 362, 446, 448, 450 451, 521f, 522, 536 iron overload, 448 iron toxicity, 448 labeling of, 364 365, 365f during lactation, 536 lecithin as, 145 146 liquid diets, 504, 602 medwatch (fda program), 365 minerals, 362t, 655 misinformation on, 34f, 362, 363 364, 503 507 natural, 34f, 349 need for, determining, 361, 362 nutrient interactions and, 409 for older adults, 603 604 omega-3 fatty acids, 159 potassium, 414 415 during pregnancy, 514, 520, 521f, 522, 523, 523f, 524, 530, 531 532 protein/amino acids, 520 protein powders, 202 quackery and, 34f regulation of, 136, 363, 364 365, 442 risks associated with, 392 393, 436, 656 659, 656t 658t salt tablets, 412 selection of, 34f, 363 364, 436, 442 smokers and, 580 statistics on use, 360 stevia, 136 structure-function claims, 364 tolerable upper intake level, 362t toxicity, 325 326, 325f, 349, 361 362 trace minerals, 442, 442n for vegetarians, 67 vitamin a, 373, 374 vitamin b12, 344 vitamin c, 352, 352f, 354, 392, 448 vitamin d, 361, 379, 380 vitamin e, 392 393 vitamin k, 384 385 vitamins, 362t, 655, 656t websites on, 365, 659 for weight loss, 290, 291t, 296 zinc, 455, 459 see also functional foods support groups, 304 surgery in obesity treatment, 285, 292 293, 293f vitamin c and, 353 sushi, 670 sustainable, defined, 711 sustainable agriculture. -see under agriculture sustainable development, 708, 711 swallowing, 72 73, 92, 92f, 599 see also choking sweat, fluid and electrolytes, 398, 412, 493, 494 sweeteners, artificial. -see artificial sweeteners sweets caffeine content of, h-1t in canadian food groups, i-9t children and, 572 in exchange lists, g-6t in food group plans, 43f, 45 glycemic index of, 116f infants and toddlers, 556 nutrient deficiencies and, 117 119 see also sugars sympathetic (nervous system), a-7 to a-8, a-8f syndrome x, 630 synergistic, defined, 623 t tagatose, 132, 133t, 134 135 tannic acid and iron absorption, 444 tanning lamps, 380 tannins, 106n, 470t taste preferences, 4 5 taste sensations, 72, 410, 600 taurine, 182n taxol, 655 tca (krebs) cycle, 218 alcohol and, 241, 241f, c-15 biotin and, 333 334 b vitamins and, 35, 347 348, 347f diagram of, 228f, 231f, c-11f to c-13f mitochondria s role, a-2, a-2n niacin and, 331 reactions of, 227 230, 228f, c-11 to c-14, c-15t, c-16f riboflavin and, 328, 330f thiamin and, 327 t-cells, 622 623 teas, 472f, 655, 656, 658t see also caffeine technology food safety, 672 673 genetic engineering, 693 697, 694f, 697t see also food industry teenagers. -see adolescence teeth calcium and, 416 dioxins and, 538 fluoride and, 460 461, 461f, 551 loss with age, 599 600 malnutrition and, e-17t smoking and, 580 structure of, 119f vitamin c and, 353, 363 see also dental caries television obesity and, 288, 569 validity of information on, 30 31 tempeh, 64, 65 temperature regulation, 579, a-7 to a-8 see also hyperthermia; hypothermia teosinte, 693, 693f teratogenic, defined, 374 term (infant), 516 terrorism, 621, 663 testosterone, 282, 434 435, a-5, a-7 tetracycline, 616 tetrahydrofolate (thf), 338 tetrahydrofolic acid, c-7f textured vegetable protein, 53, 64, 66 thermic effect of food, 254, 254f, 256, 318 thermogenesis, 253 256, 256, 307 thf (tetrahydrofolate), 338 thiamin, 327 328 overview of, 329t alcohol abuse and, 327 cooking and, 324, 328 deficiency, 244, 327, 328f food sources, 328, 328f, 329 functions of, 327, 328f, 347f rda/recommendations, 327, 328f structure of, c-5f sulfites and, 684 wernicke-korsakoff syndrome and, 239, 244, 328 index in-29 thiamin pyrophosphate (tpp), 327, 347f, c-5f thioredoxin reductase, 391n thirst, 398, 401, 410, 601 thoracic duct, 85 thrombin, 384f thrombosis, 626, 627 thromboxanes, 627 thrombus, 626 thyroid disease website, 465 thyroid gland, 417f, 456, 456f, 677 thyroid hormone, 255n, 455 456, a-4, a-5 thyroid-stimulating hormone (tsh), 456, a-4, a-5 thyroxin, 191t, 194, 455, a-5 tobacco. -see smoking/tobacco use tocopherol equivalents (te), 383 tocopherols, 381, 393, c-9f see also vitamin e tofu, 64, 65, 67n tolerable upper intake level, 18, inside front cover high doses of nutrients and, 325 326, 325f preventing toxicity, 18, 18f supplement doses, 362t tolerance level (pesticide residue), 567, 678 tomatoes, 470, 472f, 694 tongue: glossitis, 330n, 333n, 349f tooth decay. -see dental caries total iron-binding capacity (tibc), e-20 to e-21, e-21t toxemia, 528 toxicants, natural, 677 678 toxicity, 663 alcohol, 238, 244, 543 545 amino acid supplements and, 203 aspartame metabolites, 134 beta-carotene supplements, 374 b vitamin supplements, 349 food intoxications, 666 herbal remedies, 657t, 658 laboratory tests and, 21 laetrile and, 346, 653 lead, 463, 463t, 531, 553, 564, 565 liver s function and, 84 naturally occurring in foods, 677 678 nutrient-drug interactions, 617 safe vs. toxic nutrient intakes, 18, 18f solanine in potatoes, 677 supplement dosage, 325 326, 325f, 349, 361 362 vitamin a in liver, 376 see also contaminants; environmental con- taminants; foodborne illnesses; pesticides; specific nutrients tpp (thiamin pyrophosphate), 327, 347f, c-5f trabecular bone, 431 432, 432f trace minerals. -see minerals, trace trachea, 73f, 92, 92f, 94 training (physical), 480 see also physical activity transamination, 225, 226f transcription, 187 trans-fatty acids. -see fatty acids, trans- transferrin, 443 half-life of, e-19n in iron absorption, 443, 443f, 444 in iron deficiency, 446 in iron transport, 443, 445, 445f normal serum value, e-19t in pem, e-19 in zinc absorption, 452 453 transferrin saturation, e-21, e-21t transfer rna, protein synthesis and, 187, 188f transient hypertension of pregnancy, 528 transient ischemic attack (tia), 626, 627 translation, 187 in-30 index transport (nutrient), 83 85 active, 81f, 108 diffusion, 81f, 108 of electrolytes, 405 406 of lipids, 149 150, 150 153, 152f, 153f liver and, 83 84, 85f lymphatic system, 82, 83, 84 85, 149 150 vascular system and, 83 84, 84f, 85f see also specific nutrients transport proteins, 191, 192f transthyretin, e-18, e-19t travelers diarrhea, 672, 673 triacylglycerols. -see triglycerides tricarboxylic acid cycle. -see tca (krebs) cycle triglycerides, 142 blood levels, 156, 628t body vs. food composition, 139 functions of, 153 154 heart disease and, 628t, 630 hydrolysis of, 149, 151f, 155 metabolism of, 215f structure of, 142, 143f, 224f transport of, 150 152 see also fats; fatty acids trimesters, 512 tripeptidases, 185, 186f tripeptide, 183 trypsin, in protein digestion, 186f tryptophan in complementary proteins, 196f gelatin lacking, 195 niacin and, 194, 331, 332, 336 for pain/sleep, 203 serotonin and, 194 supplements, 203 tsh-releasing hormone (trh), a-5 tsh (thyroid-stimulating hormone), a-4, a-5 tuberculosis and vitamin b6, 336 tumors, 642, 643f 24-hour recall, e-3 to e-4 tyramine, mao inhibitors and, 617, 618t tyrosine, 183, 194, 209 u ubiquinone (coenzyme q10), 346 ulcers, gastrointestinal, 13f, 94, 97, 97t ulcers, pressure, 602 ultimate weight solution diet, 317t ultrahigh temperature (uht) treatment, 610, 672 umbilical cord, 510, 511f umbilicus, 510 unavailable carbohydrates, 108 see also fiber uncoupling proteins, 286 undernutrition, 20 underweight, 259 bone density and, 435 fashion and bmi, 258 259, 258f ghrelin and, 285 health risks of, 262, 264 265, 264f, 307 older adults, 602 pregnancy and, 264 265, 509, 516, 517f, 517t strategies for weight gain, 299t, 307 308 see also eating disorders; weight gain; weight loss unicef (united nations international children s emergency fund), 562 united states body weight statistics, 260f, 282f death, causes of, 24, 24t, 25t, 624f dietary guidelines for americans, 39 41, 40t hunger in, 702 705, 702f population of older adults, 593, 594f unsaturated fats, 141 replacing saturated fats, 162, 162f, 163, 164, 164t, 166f, 176f see also monounsaturated fats; polyunsaturated fats unsaturated fatty acids, 140f 142f, 141 142, 141t, 142 144, c-3t unsaturation, point of, 141 upper-body fat, 262 263, 262f, 263f urea, 226 excretion of, 194, 226, 227f synthesis of, 226, 226f urea cycle, c-15 to c-16, c-16f urine, 399, 400, 402f see also urea u.s. pharmacopoeia (usp), 363 usda food guide, 41 47 exchange system and, 47 48 food groups, choices within, 42f 43f sample menus, 48t, 49f serving sizes, 42f 43f, 46 vegetarian diets and, 44, 46 see also discretionary kcalorie allowance; food group plans usda (u.s. department of agriculture), 664, 668, 669f, 697, 703 704 uterus, 510, 511f uv light, 380, 380n v valerian, 655, 657t, 658t validity (research), 14, 15 values (beliefs) and food choices, 4 5 vanadium, 462 variables (research), 12, 14 variety (dietary), 39 absorption and, 89 overeating and, 303 in vegetarian diets, 67 for vitamins and minerals, 329 vascular system, 83 84 angiotensin and, 400 in diabetes, 640 in intestinal villi, 82f nutrient absorption and, 83 84, 84f, 85f nutrient transport and, 83 84 oxygen delivery, 84f, 483f renin and, 400 vitamin c and, 353f vitamin e and, 382 see also atherosclerosis; cardiovascular dis- ease (cvd); hypertension vasoconstrictor, 401 vasopressin, 401, a-3 see also adh (antidiuretic hormone) vegans, 64 adequacy of diet, 67 children s diets, 559 fiber and, 123 fossil fuel use in farming, 719f infants diets, 379, 557 during pregnancy, 520, 524 riboflavin and, 330 vitamin b12 and, 343, 344, 520, 524 vitamin d and, 379, 524 see also vegetarian diets vegetables antioxidants in, 391 392, 393, 470 calcium and, 65, 419, 419f, 420f in canadian food groups, i-10t cancer and, 65, 391 392, 470, 643, 644t, 645, 646t carbohydrate content of, 126 cooking of, 674 cruciferous, 456, 645, 677 discretionary kcalories and, 45 dna and, 391 392 in exchange lists, 48, g-1t, g-3t, g-4t, g-7t fat intake and, 162 163 fiber content of, 125t 5 to 9 a day campaign, 52f flavonoids in, 471, 472f in food group plans, 41t, 42f, 44, 44t, 46t, 47f, 48t, 49f, 52 glycemic index of, 116f goitrogen-containing, 677 heart disease and, 392, 471, 630, 633 intake recommendations, 41t, 44 intake statistics, 561 562, 569 nutrient density, 329, 330 nutrients in, 42f, 44, 393 starchy, 48 vitamin a in, 375 376, 375f websites on, 52f, 61, 357 see also phytochemicals; plant foods vegetarian, 64 vegetarian diets, 64 68 athletes, 492 calcium and, 65, 66 67, 67n cancer and, 65 environmental impact of, 719, 719f food pyramids for, 65 66, 66f health benefits of, 65, 175 for infants and children, 379, 557 iron and, 65 66, 444, 449, 492 omega-3 fatty acids, 67 pregnancy/lactation, 520 protein and, 65, 66, 196 supplements for, 67, 361 usda food guide and, 44, 46 vitamin b12 and, 66, 67, 343, 344 vitamin d and, 66, 67, 379 websites for, 67 zinc and, 66 see also vegans veins, 83, 84f see also vascular system vertebrae, collapse of, 432, 433f very-low-density lipoprotein. -see vldl vibrio bacteria, 665n, 665t, 670n villus/villi, 80 81, 82f violence and alcohol, 245 viscous, defined, 106 viscous fibers, 123t vision blindness, 371, 373, 373f cataracts, 604 605 in diabetes, 640 infant diet and, 550 551 leptin and, 285 macular degeneration, 605 night blindness, 373, 373f in older adults, 600, 604 605 opsin, 192 retina, structure of, 371f vitamin a and, 244, 370 371, 371f, 373, 373f vitamin e and, 382 websites on, 611 see also blindness vitamin a, 369 377 overview of, 376t 377t, 386t absorption/transport, 370 activity, 369, h-0 cancer and, 656t deficiency, 372 374, 373f, 376t, 562, 706 food sources, 346t, 374 376, 375f forms of, 369, 370f, c-5f functions of, 369 372, 371f, 373f, 436 genetically engineered foods, 694 megadoses in pregnancy, 532 precursors, 369, 370f, 375 preformed, 374 pregnancy and, 374 rda/recommendations, 374, 375f, 376t storage of, 372, 376n structure of, c-5f supplements, 372 373, 374 toxicity, 374, 376, 377t zinc and, 452, 453 see also beta-carotene vitamin a activity, 369 vitamin b1. -see thiamin vitamin b2. -see riboflavin vitamin b3. -see niacin vitamin b5, 346 vitamin b6, 336 337 overview of, 337t, 356t alcohol use and, 244 antagonists of, 336 cooking and, 336 deficiency, 244, 336, 337t, 618 food sources, 336 337, 337f, 339f functions of, 336, 337t isoniazid (inh) and, 618 rda/recommendations, 336, 337f, 339f riboflavin and, 346 structure/forms of, c-6f, c-7f toxicity, 336, 337t vitamin b12, 343 345 overview of, 345t, 356t cobalt and, 462, 462f cooking and, 344 345 deficiency, 342 344, 344f, 345t, e-20t, e-22, e-22t enterohepatic circulation, 343 folate and, 340, 342 343, 343 344, 344f, 514 food sources, 344 345, 345t functions of, 342 343, 345t gene expression and, 208, 209f intrinsic factor and absorption of, 343 for older adults, 602 603, 604 during pregnancy, 520, 521f, 524 rda/recommendations, 343, 345t serum levels, e-22, e-22t structure of, c-7f supplements, 344 vegetarian diets, 66, 67 vitamin b15, 346 vitamin b17, 346 vitamin c, 350 355 overview of, 355t, 356t active forms of, 351f anticoagulant, 656t as antioxidant, 351, 351f, 352, 354, 391, 392 cancer and, 392 cataracts and, 605 cooking and, 324, 354 deficiency, 350, 353, 353f, 355t, 356t food sources, 354, 355f, 355t, 356t functions of, 351 352, 355t heart disease and, 13f, 392, 393 for infants, 556 iron absorption and, 66, 351, 354, 444, 448, 522 iron absorption from supplements, 451 overview, 355t, 356t during pregnancy, 522 as prooxidant, 354, 448 rda/recommendations, 352 353, 352f, 355t research example, 12 15 in smokers, 580 stress and, 352 structure of, c-8f supplements, 352, 352f, 354 tooth enamel and, 363 toxicity, 353 354, 356t vitamin d, 377 379 overview of, 381t, 386t activation of, 377, 377f adolescent needs, 576 ai/recommendations, 379 380, 381t bone growth, 377, 378 calcium absorption, 377, 378, a-6 calcium and, 417, 417f, 418 calcium in bone, 434, 436 deficiency, 377f, 378 379, 381t, 551 food sources, 379, 381t forms of, 377, 381t, c-8f functions of, 377, a-6 infant needs, 551, 551t milk fortification with, 330, 330n for older adults, 603 pregnancy and, 521f, 522 523 skin color and, 380 structure of, 147f, c-8f supplements, 361, 379, 380 synthesis of, 147f, 377, 377f, 379 380, 380f, 380n, c-8f toxicity, 379, 381t vegetarian diets, 66, 67 vitamin d2, 377 vitamin d3, 377, c-8f vitamin e, 381 383 overview of, 383t, 386t activity, h-0 as antioxidant, 382, 391 for athletes, 492 beta-carotene and, 363 cancer and, 392, 656t cataracts and, 605 cooking and, 383 deficiency, 382, 383t food sources, 383, 383t functions of, 382, 383t heart disease and, 392 lungs, protection of, b-8 rda/recommendations, 382 383, 383t structure of, c-9f supplements, 392, 393 tocopherols, 381 382, 393, c-9f toxicity, 382, 393 vitamin k and, 363 vitamin impostors, 346 vitamin k, 383 385 overview of, 385t, 386t ai/recommendations, 385, 385t anticoagulants and, 617 deficiency, 383 384, 385t food sources, 385, 385t functions of, 383 384, 384f, 436 medications and, 384 structure of, c-9f synthesis of, 86, 383, 385n, 385t toxicity, 385, 385t vitamin e and, 363, 382 vitamin p, 346 vitamins, 10, 323 357, 369 388 overview of, 323 326, 326t absorption of, 79f, 325, 363 as additives, 684 adolescent needs, 576 as alternative medicines, 655 assessment tests, e-18t bioavailability of, 324, 363 brain function and, 606t for children, 560 coenzymes and, 327f cooking/losses, 324, 324t destruction of, 324t dose levels, effects of, 325 326, 325f elements in, 7t evaluating foods for, 329 for exercise, 491 493 fat-soluble. -see vitamins, fat-soluble functions of, 10, 323 impostors, 346 infant needs, 549, 549f, 556 index in-31 lactation and, 521f, 535 minimizing loss of, 674 non-b vitamins, 345 346 for older adults, 602 603 physiological vs. pharmacological effects of, 332 precursors, 324 pregnancy and, 520, 521f, 522 523, 531 532 rda and ai for, inside front cover solubility of, 324 325 storage of, 325, 336 structure of, 323, c-5f to c-9f supplement overview, 360 365, 362t, 365f tolerable upper intake level, 325 326, 362t, inside front cover toxicity of, 325 326, 325f water-soluble. -see vitamins, water-soluble websites on, 357, 365, 387 in whole grains, 51f see also b vitamins; deficiencies; dri; nutrient interactions; toxicity; specific vitamins vitamins, fat-soluble, 369 388 overview of, 324 325, 326t, 369, 385 386, 386t absorption of, 165, 369 food sources, 324 listed, 10n, 324, 369 mineral oil and, 95 olestra and, 165 storage of, 325, 369 transport of, 325, 369 websites on, 387 see also specific vitamins vitamins, water-soluble, 323 357 overview of, 324 325, 326t, 356t food sources, 325 listed, 10n, 324 websites on, 357 see also specific vitamins vitamin tablets. -see supplements vldl (very-low-density lipoprotein), 151, 151n, 153f volume, metric units, 8 volunteer health agencies, websites, 33 vo2 max, 482, 483f vomiting, 92 93, 94 acid-base balance, 413, 413n in bulimia nervosa, 274 275, 274t fluids and electrolyte imbalance, 406 by infants, 93 metabolic alkalosis and, 413n during pregnancy, 524, 524t projectile vomiting, 93 sodium and electrolyte balance, 412 w wadsworth website, 26 waist circumference, 263, 263n, e-15, e-15f waist-to-hip ratio, 263n, e-15 walnuts, 173 war and famine, 705 706 warfarin (coumadin), 617 warm-up, 481 water, 397 405 adh and retention of, 401 alcohol use and, 243 for athletes, 493 496, 494t, 496 497 blood pressure and, 401 402 blood volume and, 401 402, 403f body composition, 6, 6f bottled, 400, 401, 689 contamination of, 687 689 disinfection of, 690 electrolytes and, 404f exercise and, 496 fluoridation of, 460, 461f, 689 food composition, 6, 399t in-32 index water, continued functions of, 11, 397, 404f hard vs. soft, 400 401, 424 health effects summary, 400 401 home treatment systems, 688 689 infant needs, 549 intake recommendations, 399 401 during lactation, 535 536 losses, routes of, 399, 399n, 399t minerals in, 400 401, 420, 424 molecular structure of, 7t, b-4f, b-6, b-7f obligatory water excretion, 399 for older adults, 602 oxygenated, 505 protein intake and, 226 regulation of, 688 689 sources of, 398 399, 399t sources of drinking water, 688 thirst vs. need, 398 for travelers, 673 types of, 400 401 websites on, 691 weight loss and, 250, 297 see also beverages; dehydration; fluid balance water balance, 398 401, 399f, 399t see also electrolytes; fluid balance water intoxication, 398 water pollution/contamination bacterial, 687, 688 effects on food production, 709 groundwater, 688 infants formulas and, 553 lead poisoning, 565 nonpoint water pollution, 716, 717 safety, 687 689 seafood and, 670, 675 676, 675f soft water and, 401 water scarcity, 709, 716 water-soluble vitamins. -see vitamins, water-soluble wean, defined, 552 websites, 32 for this book, 26 assessing validity of, 30, 31, 33, 503 accredited schools, 34 adolescence, 581 aging, 611 612 agriculture, 720 aids/hiv, 648 alcohol/alcoholism, 247 allergies/adverse reactions to foods, 581 alternative therapies, 659 alzheimer s disease, 612 american dietetic association (ada), 33, 34 anorexia nervosa, 277 arthritis, 612 artificial sweeteners, 137 birth defects, 539 body weight, 266 breastfeeding, 539 bulimia nervosa, 277 caffeine, 581 calcium, 427 canadian, 26, 33, 34 cancer, 648 child nutrition, 580 581 cholesterol, 168 chronic diseases, 648 consumer groups, 33 consumer health, 648 dash diet, 648 dental caries, 127 diabetes, 33, 127, 589, 648 dietary guidelines, 40t dietitians, 33, 34 diet planning, 61 digestion and absorption, 90 digestive problems, 98 dri (dietary reference intakes), 26 drug abuse, 247 eating disorders, 277 exchange lists, 61 exercise, 499 500, 581, 648 fad diets, 321 fao, 26 fat intake, 168 fetal alcohol syndrome, 545 fiber, 127 fight bac!, 667f fitness, 499 500 5 to 9 a day campaign, 52f, 61 foodborne illnesses, 667f, 690 food pyramids, 67, 580 food safety, 690 691 food surveys research group, 26 fraud/quackery, 34 functional foods, 473 genetic engineering, 697 gestational diabetes, 539 government health agencies, 26, 33, 61, 499 500 healthy people 2010, 26 heart disease, 168 herbal supplements, 659 hunger, world, 704, 712t, 713 hyperactivity, 581 infants, 580 581 iodine, 465 iron overload, 465 irradiation, 690 journals, 33 labeling of foods, 61 lactose intolerance, 127 lead poisoning, 581 malnutrition, 204 mayo clinic, 26 medwatch (fda), 690 milk, 427, 581 minerals, 365, 427, 465 neural tube defects, 357 nhanes, 26 nutrition, overviews of, 26 nutritional genomics, 211 organic foods, 691 osteoporosis, 437 pregnancy, 539 professional organizations, 33 sickle-cell anemia, 204 smoking/tobacco use, 581, 648 sodium, 427 spina bifida, 357 stroke, 648 sugars, 127 supplements, 365, 659 thyroid disease, 465 vegetables, 357 vegetarian diets, 67 vitamins, 357, 365 volunteer health agencies, 33 water, 691 weight control, 581, 589 who, 26 wic program, 539 weight, metric units, 8, inside back cover weight (body), 258 267 accepting yourself, 259t of adults in u.s., 260f, 282f alzheimer s disease and, 607 of athletes, 258, 259, 261 262, 270, 271 272, 271f body image and, 258 260, 258f, 272, 276, 289 cardiorespiratory fitness and, 266 energy consumption and, 10 food choices and, 5 ghrelin and, 285 286 for healthy adults, 258 260, 259t, 260 263, 260f, 260t of infants, 547f, 548f. -see also birthweight measurement of, e-6 to e-7, e-7f, e-8f to e-15f, e-14 to e-15 mortality and, 263, 264f osteoporosis risk and, 264 overweight vs. overfat, 258, 259 smoking and, 579 see also body composition; fats (body); obesity; obesity treatment; overweight; underweight; weight gain; weight loss; weight management weight cycling, 274, 289f weight-for-age percentiles, 548f, e-8f, e-11f weight-for-length percentiles, e-10f weight-for-stature percentiles, e-13f weight gain, 307 308 alcohol and, 243 by athletes, 272 cognitive influences, 251 exercise and, 254, 308 fat vs. muscle, 308 health and, 263 266 of infants, 547 548, 547f, 548f leptin and, 284 285, 285f lipoprotein lipase (lpl), 282 283 marijuana and, 579 medications and, 615 overnutrition, 20, 232 233 during pregnancy, 515 518, 517f, 517t, 518f, 528, 529 preventing, 306 proteins (dietary) and, 194 set-point theory of, 283 strategies for, 299t, 307 308 weight loss, 294 299 behavior modification, 303 benefits of, 294 bill of rights, 290t body composition and, 250 bone density and, 435 carbohydrates and, 120 for children, 569 571 cocaine use, 579 dangers of, 289 291 in diabetes, 641 eating plans, 295 298, 295t, 296t, 297f, 299t exercise and, 254, 299 301, 305, 495 expectations and goals, 294 295, 294f fad diets, 290, 315 321, 316t, 317t, 320t fat and, 156, 295t, 296t, 297f, 299t fat vs. lean tissue, 250, 296 fish and, 159 gimmicks, 291 hypertension and, 635 kcalories and, 295 296, 295t ketosis-producing diets, 113, 235, 319 320, 320t leptin and, 284 285, 285f low-fat foods, 296 maintaining, 283, 285 metabolism and, 283, 300, 305 myths vs. facts, 315 320, 316t need for, judging, 288 289 in older adults, 598, 602 pregnancy, after, 518, 535 pregnancy, during 516, 532 proteins (dietary) and, 200 regaining weight, 282 283, 298 safe rate of, 295 set-point theory of, 283 spot reducing, 301 302, 489 statistics on, 288 strategies for, 299 302, 299t successful weight-loss maintenance, 305 supplements for, 291t, 296 support groups, 304 undernutrition, 20 vs. fat loss, 320 websites on, 581, 589 see also diets; eating disorders; obesity treatment weight management, 281 310 artificial sweeteners and, 135 attitude and, 303 304 calcium and, 416 carbohydrates, 101, 113, 297, 298 dietary guidelines and, 40t, 570 exchange groups and, g-2 exercise and, 299 302, 479, 482, 489 fiber and, 123 food records for, 304f glycemic index and, 115 116 health and, 294 295 healthy people 2010 goals, 23t heart disease and, 630 nutrient density and, 39, 45 during pregnancy, 515 518, 517f, 517t proteins (dietary) and, 200 public health strategies, 306 307, 306t strategies for, 299t successful weight-loss maintenance, 305 sugar and, 120 vegetarian diets and, 65 water and, 297 weight cycling and, 289f see also diet planning weight training, 435, 480t, 484 well water, 400 wernicke-korsakoff syndrome, 239, 244, 328 wheat, 50 51, 50f see also breads; grains wheat germ, 50f whey protein (supplement), 202 white blood cells, 622 623 white flour. -see grains whole grain. -see grains, whole who (world health organization), 664 nutrition standards, 19, 121, i-1 vitamin a and, 372 373 website/address, 26 see also fao wic (special supplemental food program for women, infants, and children), 527, 529, 536, 539 wilson s disease, 459 wine, 238, 239, 239f, 244t women calcium intake, 421, 436 iron intake, 449 iron losses, 443n, 446, 577 see also gender differences world health organization. -see who world wide web, 32 see also websites x xanthophylls, 376 xenical, 292n xerophthalmia, 373 xerosis, 373 xylitol, 132, 136t xylose, c-2f index in-33 y yeast, 344, 453n yersiniosis, 665t yogurt, 86, 111, 162 yohimbe, 657t yohimbine, 291t z zeaxanthin, 370n, 470n, 472f zinc, 452 455, 464t overview of, 455t absorption of, 66, 452, 453f, 455n, 522 in breast milk, 551 copper absorption and, 453, 459 deficiency, 452, 453, 453f, 455t, 562 enteropancreatic circulation, 452, 453f food sources, 66, 454, 454f functions of, 452, 453, 455t, 522 iron and, 453, 522 metabolism, 452 453, 453f nutrient interactions, 453 phytates and, 452 in pregnancy, 521f, 522 rda/intake recommendations, 454, 454f, 455t storage in liver, 453f supplements, 455, 459 toxicity, 454, 455t transport of, 452 453 vegetarian diets, 66 zinc gluconate, 455 zone diet, 317t zygote, 510, 511f, 512f aids to calculation many mathematical problems have been worked out in the how to sections of the text and practice problems have been provided in the nutrition calculations sections at the end of some chapters. -these pages offer additional help and examples. -conversions a conversion factor is a fraction that converts a measure- ment expressed in one unit to another unit for example, from pounds to kilograms or from feet to meters. -to create a conversion factor, an equality (such as 1 kilogram (cid:2) 2.2 pounds) is expressed as a fraction: 1 kg 2.2 lb and 2.2 lb 1 kg to convert the units of a measurement, use the fraction with the desired unit in the numerator. -example 1: convert a weight of 130 pounds to kilograms. -multiply 130 pounds by the conversion factor that includes both pounds and kilograms, with the desired unit (kilo- grams) in the numerator: 130 lb (cid:3) 1 kg (cid:2) 130 kg (cid:2) 59 kg 2.2 lb 2.2 the following examples show how to calculate speci c percentages. -example 4: suppose your energy intake for the day is 2000 kcalories (kcal) and your recommended energy intake is 2400 kcalories. -what percent of the recommended energy intake did you consume? -divide your intake by the recommended intake. -2000 kcal (intake) (cid:4) 2400 kcal (recommended) (cid:2) 0.83 multiply by 100 to express the decimal as a percent. -0.83 (cid:3) 100 (cid:2) 83% example 5: suppose a man s intake of vitamin c is 120 milligrams and his rda is 90 milligrams. -what percent of the rda for vitamin c did he consume? -divide the intake by the recommended intake. -120 mg (intake) (cid:4) 90 mg (rda) (cid:2) 1.33 multiply by 100 to express the decimal as a percent. -1.33 (cid:3) 100 (cid:2) 133% alternatively, to convert a measurement from one unit of measure to another, multiply the given measurement by the appropriate equivalent found in the accompanying table of weights and measures. -example 6: dietary recommendations suggest that carbo- hydrates provide 45 to 65 percent of the day s energy intake. -if your energy intake is 2000 kcalories, how much carbohy- drate should you eat? -example 2: convert 64 uid ounces to liters. -locate the equivalent measure from the table (1 ounce = 0.03 liter) and multiply the number of ounces by 0.03: because this question has a range of acceptable answers, work the problem twice. -first, use 45% to nd the least amount you should eat. -64 oz (cid:3) 0.03 oz/l (cid:2) 1.9 l percentages a percentage is a fraction whose denominator is 100. for example: 50% (cid:2) 50 100 like other fractions, percentages are used to express a por- tion of a quantity. -fractions whose denominators are num- bers other than 100 can be converted to percentages by rst dividing the numerator by the denominator and then multi- plying the result by 100. example 3: express 5/8 as a percent. -5 (cid:2) 5 (cid:4) 8 = 0.625 8 0.625 (cid:3) 100 = 62.5% w divide 45 by 100 to convert to a decimal. -45 (cid:4) 100 (cid:2) 0.45 multiply kcalories by 0.45. -2000 kcal (cid:3) 0.45 (cid:2) 900 kcal divide kcalories by 4 to convert carbohydrate kcal to grams. -900 kcal (cid:4) 4 kcal/g (cid:2) 225 g now repeat the process using 65% to nd the maximum number of grams of carbohydrates you should eat. -divide 65 by 100 to convert it to a decimal. -65 (cid:4) 100 (cid:2) 0.65 multiply kcalories by 0.65. -2000 kcal (cid:3) 0.65 (cid:2) 1300 kcal divide kcalories by 4 to convert carbohydrate kcal to grams. -1300 kcal (cid:4) 4 kcal/g (cid:2) 325 g if you plan for between 45% and 65% of your 2000-kcalorie intake to be from carbohydrates, you should eat between 225 grams and 325 grams of carbohydrates. -energy 1 millijoule (mj) (cid:2) 240 kcalories (kcal) 1 kilojoule (kj) (cid:2) 0.24 kcalories (kcal) 1 kcalorie (kcal) (cid:2) 4.2 kilojoule (kj) 1 g alcohol (cid:2) 7 kcal (cid:2) 29 kj 1 g carbohydrate (cid:2) 4 kcal (cid:2) 17 kj 1 g fat (cid:2) 9 kcal (cid:2) 37 kj 1 g protein (cid:2) 4 kcal (cid:2) 17 kj temperature to change from fahrenheit ( f) to celsius ( c), subtract 32 from the fahrenheit measure and then multiply that result by 0.56. to change from celsius ( c) to fahrenheit ( f), multiply the celsius measure by 1.8 and add 32 to that result. -a comparison of some useful temperatures is given below. -boiling point body temperature freezing point celsius 100 c 37 c 0 c fahrenheit 212 f 98.6 f 32 f weights and measures length 1 centimeter (cm) = 0.39 inches (in) 1 foot (ft) (cid:2) 30 centimeters (cm) 1 inch (in) (cid:2) 2.54 centimeters (cm) 1 meter (m) (cid:2) 39.37 inches (in) weight 1 gram (g) (cid:2) 0.001 kilogram (kg) (cid:2) 1000 milligram (mg) (cid:2) .035 ounce (oz) 1 kilogram (kg) (cid:2) 1000 grams (g) (cid:2) 2.2 pounds (lb) 1 microgram ( g) (cid:2) 0.001 milligram (mg) 1 milligram (mg) (cid:2) 0.001 gram (g) (cid:2) 1000 microgram ( g) 1 ounce (oz) (cid:2) 28 grams (g) (cid:2) 0.03 kilograms (kg) 1 pound (lb) (cid:2) 454 grams (g) (cid:2) 0.45 kilograms (kg) (cid:2) 16 ounces (oz) volume 1 cup (cid:2) 16 tablespoons (tbs or t) (cid:2) 0.25 liter (l) (cid:2) 236 milliliters (ml, commonly rounded to 250 ml) (cid:2) 8 ounces (oz) 1 liter (l) (cid:2) 33.8 uid ounces ( oz) (cid:2) 0.26 gallons (gal) (cid:2) 2.1 pints (pt) (cid:2) 1.06 quarts (qt) (cid:2) 1000 milliliters (ml) 1 milliliter (ml) (cid:2) 0.001 liter (l) (cid:2) 0.03 uid ounces ( oz) 1 ounce (oz) (cid:2) 0.03 liter (l) (cid:2) 30 milliliters (ml) 1 pint (pt) (cid:2) 2 cups (c) (cid:2) 0.47 liters (l) (cid:2) 16 ounces (oz) 1 quart (qt) (cid:2) 4 cups (c) (cid:2) 0.95 liters (l) (cid:2) 32 ounces (oz) 1 tablespoon (tbs or t) (cid:2) 3 teaspoons (tsp) (cid:2)15 milliliters (ml) 1 teaspoon (tsp) (cid:2) 5 milliliters (ml) 1 gallon (gal) (cid:2) 16 cups (c) (cid:2) 3.8 liters (l) (cid:2) 128 ounces (oz) x daily values for food labels the daily values are standard values developed by the food and drug administration (fda) for use on food labels. -the values are based on 2000 kcalories a day for adults and children over 4 years old. -chapter 2 provides more details. -food component amount calculation factors 20 mg ne carbohydrate (total) fat saturated fat cholesterol fiber protein sodium potassium 65 g 20 g 300 mg 300 g 25 g 50 g 2400 mg 3500 mg 30% of kcalories 10% of kcalories same regardless of kcalories 60% of kcalories 11.5 g per 1000 kcalories 10% of kcalories same regardless of kcalories same regardless of kcalories g lossary of nutrient measures kcal: kcalories; a unit by which energy is measured (chapter 1 provides more details). -g: grams; a unit of weight equivalent to about 0.03 ounces. -mg: milligrams; one-thousandth of a gram. -g: micrograms; one-millionth of a gram. -iu: international units; an old measure of vitamin activity determined by biological methods (as opposed to new measures that are determined by direct chemical analyses). -many forti ed foods and supplements use iu on their labels. -for vitamin a, 1 iu (cid:2) 0.3 g retinol, 3.6 g (cid:3)-carotene, or 7.2 g other vitamin a carotenoids for vitamin d, 1 iu (cid:2) 0.02 g cholecalciferol for vitamin e, 1 iu (cid:2) 0.67 natural (cid:4)-tocopherol (other conversion factors are used for different forms of vitamin e) mg ne: milligrams niacin equivalents; a measure of niacin activity (chapter 10 provides more details). -1 ne (cid:2) 1 mg niacin (cid:2) 60 mg tryptophan (an amino acid) g dfe: micrograms dietary folate equivalents; a measure of folate activity (chapter 10 provides more details). -1 g dfe (cid:2) 1 g food folate (cid:2) 0.6 g forti ed food or supplement folate taken with food (cid:2) 0.5 g supplement folate taken on an empty stomach g rae: micrograms retinol activity equivalents; a measure of vitamin a activity (chapter 11 provides more details). -1 g rae (cid:2) 1 g retinol (cid:2) 12 g (cid:3)-carotene (cid:2) 24 g other vitamin a carotenoids mmol: millimoles; one-thousanth of a mole, the molecular weight of a substance. -to convert mmol to mg, multiply by the atomic weight of the substance. -for sodium, mmol (cid:5) 23 (cid:2) mg na for chloride, mmol (cid:5) 35.5 (cid:2) mg c| for sodium chloride, mmol (cid:5) 58.5 (cid:2) mg nac| nutrient proteina thiamin ribo avin niacin biotin pantothenic acid vitamin b6 folate vitamin b12 vitamin c vitamin a vitamin d vitamin e vitamin k calcium iron zinc iodine copper chromium selenium molybdenum manganese chloride magnesium phosphorus amount 50 g 1.5 mg 1.7 mg 300 g 10 mg 2 mg 400 g 6 g 60 mg 5000 iub 400 iub 30 iub 80 g 1000 mg 18 mg 15 mg 150 g 2 mg 120 g 70 g 75 g 2 mg 3400 mg 400 mg 1000 mg athe daily values for protein vary for different groups of people: pregnant women, 60 g; nursing mothers, 65 g; infants under 1 year, 14 g; children 1 to 4 years, 16 g. bequivalent values for nutrients expressed as iu are: vitamin a, 1500 rae (assumes a mixture of 40% retinol and 60% beta-carotene); vitamin d, 10 g; vitamin e, 20 mg. y body mass index (bmi) 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 body weight (pounds) 86 89 92 91 94 96 100 105 110 115 119 124 129 134 138 143 148 153 158 162 167 172 177 181 186 191 99 104 109 114 119 124 128 133 138 143 148 153 158 163 168 173 178 183 188 193 198 97 102 107 112 118 123 128 133 138 143 148 153 158 163 168 174 179 184 189 194 199 204 95 100 106 111 116 122 127 132 137 143 148 153 158 164 169 174 180 185 190 195 201 206 211 98 104 109 115 120 126 131 136 142 147 153 158 164 169 175 180 186 191 196 202 207 213 218 102 107 113 118 124 130 135 141 146 152 158 163 169 175 180 186 191 197 203 208 214 220 225 105 110 116 122 128 134 140 145 151 157 163 169 174 180 186 192 197 204 209 215 221 227 232 108 114 120 126 132 138 144 150 156 162 168 174 180 186 192 198 204 210 216 222 228 234 240 112 118 124 130 136 142 148 155 161 167 173 179 186 192 198 204 210 216 223 229 235 241 247 115 121 127 134 140 146 153 159 166 172 178 185 191 198 204 211 217 223 230 236 242 249 255 118 125 131 138 144 151 158 164 171 177 184 190 197 203 210 216 223 230 236 243 249 256 262 122 128 135 142 149 155 162 169 176 182 189 196 203 209 216 223 230 236 243 250 257 263 270 126 132 139 146 153 160 167 174 181 188 195 202 209 216 222 229 236 243 250 257 264 271 278 129 136 143 150 157 165 172 179 186 193 200 208 215 222 229 236 243 250 257 265 272 279 286 132 140 147 154 162 169 177 184 191 199 206 213 221 228 235 242 250 258 265 272 279 287 294 136 144 151 159 166 174 182 189 197 204 212 219 227 235 242 250 257 265 272 280 288 295 302 141 148 155 163 171 179 186 194 202 210 218 225 233 241 249 256 264 272 280 287 295 303 311 144 152 160 168 176 184 192 200 208 216 224 232 240 248 256 264 272 279 287 295 303 311 319 148 156 164 172 180 189 197 205 213 221 230 238 246 254 263 271 279 287 295 304 312 320 328 151 160 168 176 185 193 202 210 218 227 235 244 252 261 269 277 286 294 303 311 319 328 336 155 164 172 181 190 198 207 216 224 233 241 250 259 267 276 284 293 302 310 319 328 336 345 height 4(cid:2)10(cid:3) 4(cid:2)11(cid:3) 5(cid:2)0(cid:3) 5(cid:2)1(cid:3) 5(cid:2)2(cid:3) 5(cid:2)3(cid:3) 5(cid:2)4(cid:3) 5(cid:2)5(cid:3) 5(cid:2)6(cid:3) 5(cid:2)7(cid:3) 5(cid:2)8(cid:3) 5(cid:2)9(cid:3) 5(cid:2)10(cid:3) 5(cid:2)11(cid:3) 6(cid:2)0(cid:3) 6(cid:2)1(cid:3) 6(cid:2)2(cid:3) 6(cid:2)3(cid:3) 6(cid:2)4(cid:3) 6(cid:2)5(cid:3) 6(cid:2)6(cid:3) under- weight (<18.5) healthy weight (18.5 24.9) overweight (25 29.9) obese ( 30) find your height along the left-hand column and look across the row until you nd the number that is closest to your weight. -the number at the top of that column identi es your bmi. -chapter 8 describes how bmi correlates with disease risks and de nes obesity, and chapter 16 presents bmi for children and adolescents. -the area shaded in blue represents healthy weight ranges. -the gure below presents silhouettes of various bmi. -women 17 18 20 22.5 24 32 35 men 18 21 23.5 24.5 26.5 31.5 37 source: reprinted from material of the dietitians of canada. -z - -Book 5: -guidelines world health organization 2020 guidelines on physical activity and sedentary behaviour fiona c bull ,1,2 salih s al- ansari,3 stuart biddle,4 katja borodulin,5,6 matthew p buman ,7 greet cardon,8 catherine carty,9,10 jean- philippe chaput ,11 sebastien chastin ,12 roger chou,13 paddy c dempsey,14,15 loretta dipietro,16 ulf ekelund ,17,18 joseph firth,19,20 christine m friedenreich,21 leandro garcia,22 muthoni gichu,23 russell jago ,24 peter t katzmarzyk,25 estelle lambert ,26 michael leitzmann,27 karen milton ,28 francisco b ortega,29 chathuranga ranasinghe,30 emmanuel stamatakis ,31 anne tiedemann,32 richard p troiano ,33 hidde p van der ploeg,34,35 vicky wari,36 juana f willumsen1 abstract objectives to describe new who 2020 guidelines on physical activity and sedentary behaviour. -methods the guidelines were developed in accordance with who protocols. -an expert guideline development group reviewed evidence to assess associations between physical activity and sedentary behaviour for an agreed set of health outcomes and population groups. -the assessment used and systematically updated recent relevant systematic reviews; new primary reviews addressed additional health outcomes or subpopulations. -results the new guidelines address children, adolescents, adults, older adults and include new specific recommendations for pregnant and postpartum women and people living with chronic conditions or disability. -all adults should undertake 150 300 min of moderate- intensity, or 75 150 min of vigorous- intensity physical activity, or some equivalent combination of moderate- intensity and vigorous- intensity aerobic physical activity, per week. -among children and adolescents, an average of 60 min/day of moderate- to- vigorous intensity aerobic physical activity across the week provides health benefits. -the guidelines recommend regular muscle- strengthening activity for all age groups. -additionally, reducing sedentary behaviours is recommended across all age groups and abilities, although evidence was insufficient to quantify a sedentary behaviour threshold. -conclusion these 2020 who guidelines update previous who recommendations released in 2010. they reaffirm messages that some physical activity is better than none, that more physical activity is better for optimal health outcomes and provide a new recommendation on reducing sedentary behaviours. -these guidelines highlight the importance of regularly undertaking both aerobic and muscle strengthening activities and for the first time, there are specific recommendations for specific populations including for pregnant and postpartum women and people living with chronic conditions or disability. -these guidelines should be used to inform national health policies aligned with the who global action plan on physical activity 2018 2030 and to strengthen surveillance systems that track progress towards national and global targets. -introduction in 2018, the world health assembly (wha) approved a new global action plan on physical activity (gappa) 2018 20301 and adopted a new voluntary global target to reduce global levels of physical inactivity in adults and adolescents by 15% by 2030. as part of the wha resolution (wha71.6), member states requested that who update the 2010 global recommendations on physical activity for health.2 global and national guidelines on physical activity are a central component of a comprehen- sive and coherent governance and policy frame- work for public health action. -who recommends all countries establish national guidelines and set physical activity targets. -to help support popula- tions to achieve the targets and maintain healthy levels of physical activity, all countries are advised to develop and implement appropriate national and subnational policies and programmes to enable people of all ages and abilities to be physically active and improve health. -given that the most recent global estimates show that one in four (27.5%) adults3 and more than three- quarters (81%) of adolescents4 do not meet the recommendations for aerobic exercise, as outlined in the 2010 global recommendations on physical activity for health,2 there is an urgent need to increase priority and investment directed towards services to promote physical activity both within health and other key sectors. -these data also reveal no overall improvement in global levels of participation over the last two decades and substan- tial gender differences.3 4 furthermore, national data consistently show inequalities in participation by age, gender, disability, pregnancy, socioeconomic status and geography,1 amplifying the need to inten- sify investment in physical activity. -this paper reports on the development of new who guidelines on physical activity and sedentary behaviour.5 these guidelines provide evidence- based public health recommendations concerning the amount (frequency, intensity, duration) and types of physical activity that offer significant health 1451 for numbered affiliations see end of article. -correspondence to professor fiona c bull, physical activity unit, department of health promotion, world health organization, geneva, ge, switzerland; bullf@ who. -int accepted 7 september 2020 author(s) (or their employer(s)) 2020. re- use permitted under cc by. -published by bmj. -to cite: bull fc, al- ansari ss, biddle s, et al. -br j sports med 2020;54:1451 1462. bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 guidelines table 1 glossary of terms term definition aerobic physical activity activity in which the body s large muscles move in a rhythmic manner for a sustained period of time. -aerobic activity also called endurance activity improves cardiorespiratory fitness. -examples include walking, running, swimming and bicycling. -balance training static and dynamic exercises that are designed to improve an individual s ability to withstand challenges from postural sway or destabilising stimuli caused by self- motion, the environment or other objects. -bone- strengthening activity disability physical activity primarily designed to increase the strength of specific sites in bones that make up the skeletal system. -bone- strengthening activities produce an impact or tension force on the bones that promotes bone growth and strength. -examples include any type of jumps, running and lifting weights. -from the international classification of functioning, disability and health, an umbrella term for impairments, activity limitations and participation restrictions, denoting the negative aspects of the interaction between an individual (with a health condition) and that individual s contextual factors (environmental and personal factors). -domains of physical activity physical activities can be undertaken in various domains, including one of more of the following: leisure, occupation, education, home and/or transport. -household domain physical activity leisure- domain physical activity physical activity undertaken in the home for domestic duties (such as cleaning, caring for children, gardening, etc). -physical activity performed by an individual that is not required as an essential activity of daily living and is performed at the discretion of the individual. -examples include sports participation, exercise conditioning or training and recreational activities such as going for a walk, dancing and gardening. -light- intensity physical activity (lpa) on an absolute scale, light intensity refers to physical activity that is performed between 1.5 and 3 mets. -on a scale relative to an individual s personal capacity, light- intensity physical activity is usually a 2 4 on a rating scale of perceived exertion scale of 0 10. examples include slow walking, bathing or other incidental activities that do not result in a substantial increase in heart rate or breathing rate. -metabolic equivalent of task (met) moderate- intensity physical activity (mpa) the metabolic equivalent of task, or simply metabolic equivalent, is a physiological measure expressing the intensity of physical activities. -one met is the energy equivalent expended by an individual while seated at rest, usually expressed as mlo2/kg/min. -on an absolute scale, moderate- intensity refers to the physical activity that is performed between 3 and <6 times the intensity of rest (mets). -on a scale relative to an individual s personal capacity, mpa is usually a 5 or 6 on a rating scale of perceived exertion scale of 0 10. moderate- to- vigorous intensity physical activity (mvpa) multicomponent physical activity on an absolute scale, mvpa refers to the physical activity that is performed at >3 mets (ie, >3 times the intensity of rest). -on a scale relative to an individual s personal capacity, mpa is usually a 5 or above on a scale of 0 10. multicomponent physical activity are activities that can be done at home or in a structured group or class setting and combine all types of exercise (aerobic, muscle strengthening and balance training) into a session, and this has been shown to be effective. -an example of a multicomponent physical activity programme could include walking (aerobic activity), lifting weights (muscle strengthening) and could incorporate balance training. -examples of balance training can include walking backwards or sideways or standing on one foot while doing an upper body muscle- strengthening activity, such as bicep curls. -dancing also combines aerobic and balance components. -occupation domain physical activity see work domain physical activity. -physical activity (pa) any bodily movement produced by skeletal muscles that requires energy expenditure. -physical inactivity an insufficient physical activity level to meet present physical activity recommendations. -recreational screen time time spent watching screens (television (tv), computer, mobile devices) for purposes other than those related to school or work. -sedentary screen time sedentary behaviour time spent watching screen- based entertainment while sedentary, either sitting, reclining or lying. -does not include active screen- based games where physical activity or movement is required. -any waking behaviour characterised by an energy expenditure of 1.5 mets or lower while sitting, reclining or lying. -most desk- based office work, driving a car and watching television are examples of sedentary behaviours; these can also apply to those unable to stand, such as wheelchair users. -the guidelines operationalise the definition of sedentary behaviour to include self- reported low movement sitting (leisure time, occupational and total), tv viewing or screen time and low levels of movement measured by devices that assess movement or posture. -transport domain physical activity physical activity performed for the purpose of getting to and from places, and refers to walking, cycling and wheeling (ie, the use of non- motorised means of locomotion with wheels, such as scooters, roller- blades, manual wheelchair, etc). -in some contexts, operation of a boat for transport could also be considered transport- related physical activity. -vigorous- intensity physical activity (vpa) on an absolute scale, vigorous intensity refers to physical activity that is performed at 6.0 or more mets. -on a scale relative to an individual s personal capacity, vpa is usually a 7 or 8 on a rating scale of perceived exertion scale of 0 10. work domain physical activity physical activity undertaken during paid or voluntary work. -benefits and mitigate health risks (for definitions see table 1). -these guidelines have been developed for children, adolescents, adults, older adults and, for the first time, include specific recom- mendations on physical activity for pregnant and postpartum women and people living with chronic conditions or disability. -in addition, for the first time, these who guidelines address the health impact of sedentary behaviour. -the new who guidelines update previous who recommendations on physical activity for health released in 20102 with the most recent advances in the evidence base for these behaviours and associated selected health consequences. -these new guidelines, together with the guidelines on physical activity, sedentary behaviour and sleep for children under 5 years of age,6 provide evidence- updated recommendations for physical activity and sedentary behaviour across the life course. -the primary audiences and users of these guidelines are policy makers in ministries of health, education, sport, transport, envi- ronment, social or family welfare and related sectors, working in high- income as well as low- income and middle- income coun- tries (lmics), who formulate country- specific guidelines and who develop national or subnational plans and programmes to increase physical activity and reduce sedentary behaviours across the life course. -additional key users of these guidelines include researchers and those working in health services providing advice and guidance (such as community health workers, primary, secondary or tertiary nurses or doctors), allied health 1452 bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 guidelines table 2 criteria for determination of the certainty of evidence (a) and interpretation of the strength of recommendations (b) a high moderate low very low b strong recommendation conditional recommendations criteria for determining the certainty of evidence very confident that the true effect lies close to that of the estimate of the effect. -moderately confident in the effect estimate. -the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different. -confidence in the effect estimate is limited. -the true effect may be substantially different from the estimate of the effect. -very little confidence in the effect estimate. -the true effect is likely to be substantially different from the estimate of effect. -interpretation of the strength of recommendation strong recommendations communicate the message that the guideline is based on the confidence that the desirable effects of adherence to the recommendation outweigh the undesirable consequences. -conditional recommendations are made when there is less certainty about the balance between the benefits and harms or disadvantages of implementing a recommendation, or if the recommendations might not be applicable to all the population group. -and exercise professionals and non- governmental organisations. -communication of these guidelines to members of the public is essential and requires tailoring of the core messages to appro- priate and accessible language and formats relevant to cultural contexts in order to be effective. -methods and process for developing the who guidelines the guidelines were developed in accordance with the processes set out in the who handbook for guidelines development7 and commenced in 2019. a guideline development group (gdg) was established comprising relevant experts from required disciplines as well as policy makers and end users of the recommendations, with regional and gender balance. -details of the members of the gdg are available.5 at the first meeting in july 2019, the gdg reviewed and finalised the scope of the guidelines and agreed on the set of population, intervention or exposure, comparator and outcome (pi/eco) questions and critical and important outcomes to be assessed (table 2). -the gdg did not include sleep as a behaviour within the scope of these guidelines but did recognise sleep as an important health outcome when considering the impact of physical activity. -between august and february 2020, the who secretariat coordinated the commissioning of literature searches and systematic evidence reviews and the gdg subworking groups met virtually to review, summarise and draft preliminary recommendations. -updating searches and new evidence reviews the who guidelines on physical activity and sedentary behaviour were developed by using, and systematically updating, the evidence collated for the development of other recent national physical activity guidelines that met the following three criteria: (1) the evidence reviews had been conducted according to standard and rigorous systematic processes that were well documented; (2) the assessment of the certainty of the evidence used the grading of recommendations assessment, develop- ment and evaluation (grade) method or an equivalent meth- odology that was clearly described and documented and (3) the evidence reviews addressed the populations of interest with no restrictions to country or country income level. -for these guidelines on children and adolescents, systematic reviews undertaken by poitras et al,8 carson et al9 and okely et al10 were used and updated. -for pregnant women, the system- atic review conducted to inform the 2019 canadian guideline for physical activity throughout pregnancy11 was used and updated. -for all other age and subpopulation groups, the scien- tific report12 of the physical activity guidelines advisory group developed to inform the physical activity guidelines for amer- icans, second edition13 was used and updated. -where gaps in existing evidence were identified, new umbrella reviews were commissioned and full details of these are available elsewhere.5 to update the systematic reviews, an agreed set of search terms, databases and search methods, as well as standardised data extraction protocols, were employed to update the evidence. -a search for systematic reviews and pooled analyses of cohort studies was conducted for the period from 2017 up to september 2019. the following databases were searched: pubmed, cinahl, medline, embase, psychinfo, sportdiscus and cochrane to identify reviews that were peer- reviewed, written in english with no restriction on country or country income group and inclusive of reviews including studies using subjective or objectively measured physical activity or sedentary behaviour. -searches were limited to the english language, due to resource constraint and previous experience in the field indicating that other language searches yielded very few, if any additional reviews.14 table 3 provides a summary of the health outcomes assessed for each subpopulation. -reviews that examined an association (based on levels above or below a threshold of physical activity or sedentary behaviour), and also reviews that explored the dose- response relation- ship between these behaviours and health- related outcomes were considered. -in addition, six new umbrella reviews were commissioned to address health outcomes and populations not addressed by the above recent national physical activity guide- lines; these umbrella reviews focused on the health impact of physical activity in people living with hiv/aids, osteoporosis and sarcopenia, the prevention of falls in older adults, the risk of adverse outcomes in adults and the health impacts of occupa- tional physical activity. -the gdg reconvened in february 2020 to review the evidence and finalise a draft set of recommendations. -they examined the quality of research contributing to each outcome identified in the pi/eco questions and assessed the overall certainty of evidence (table 2) taking into consideration the risk of bias, inconsistency, imprecision, indirectness of the evidence and publication bias across each outcome, using the grade framework to rate the certainty of the evidence for each pe/ico.15 evidence profiles detailing this information for each pi/eco are available. -the gdg considered the proposed wording of the recom- mendations and rated the strength of the recommendations as strong or conditional (table 2) based on the balance of benefits to harms, the certainty of evidence, sensitivity to values and pref- erences and the potential impact on gender, social and health equity, as well as acceptability, feasibility and resource implica- tions. -the assessment of the overall certainty of the evidence 1453 bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 guidelines s t l u d a d n a n e r d l i h c t s o p d n a y c n a n g e r p * y t i l i b a s i d h t i w * s n o i t i d n o c c i n o r h c m u t r a p , k t s , d p , s m l a c i t i r c d h d a , h c s d n a r e c n a c l a c i t i r c c fi i c e p s - r e c n a c i v h , d 2 t , t h l a c i t i r c r e c n a c l a c i t i r c e c n e r r u c e r , d i , d i h c s , d c m , i c s , s m l a c i t i r c i v h , d 2 t , t h l a c i t i r c k t s , d p , i c s , s m l a c i t i r c i v h , d 2 t , t h l a c i t i r c d i , i c s , s m l a c i t i r c i v h , d 2 t , t h l a c i t i r c l a c i t i r c l a c i t i r c t n a t r o p m i l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c 5 6 r e v o s t l u d a 8 1 r e v o s t l u d a s r a e y a p s r a e y b s l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c t n a t r o p m i t n a t r o p m i l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c t n a t r o p m i t n a t r o p m i l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c s r a e y 4 6 8 1 s t l u d a a p b s d n a a p s r a e y 7 1 5 e c n a t r o p m i s e m o c t u o l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c t n a t r o p m i t n a t r o p m i l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c t n a t r o p m i . -, d c m d h d a l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c l a c i t i r c t n a t r o p m i , h c s , k t s , d p , d i t n a t r o p m i , i c s , s m d 2 t , t h , y t i l a t r o m c fi i c e p s - e s u a c d n a e s u a c - l l a s t n e v e e s r e v d a h t l a e h c i l o b a t e m o d r a c i s e m o c t u o e v i t i n g o c h t l a e h e n o b s n o i t a c i l p m o c y r e v i l e d n o i s s e r g o r p e s a e s i d a i s p m a l c e - e r p / n o i s n e t r e p y h l a n o i t a t s e g s u t i l l e m s e t e b a d i l a n o i t a t s e g e f i l f o y t i l a u q d e t a l e r - h t l a e h s e i r u n j i d e t a l e r - l l a f d n a s l l a f y t i l i b a l a n o i t c n u f s e m o c t u o l a t e f s e t e b a d 2 i e p y t f o e c n e d i c n i n o i s n e t r e p y h f o e c n e d i c n i r e c n a c f o e c n e d i c n i d v c f o e c n e d i c n i ) n o i s s e r p e d d n a y t e i x n a f o s m o t p m y s ( h t l a e h l a t n e m s n o i t i d n o c d b r o m o c i f o k s i r s e m o c t u o l a i c o s o h c y s p r u o i v a h e b l a i c o s o r p p e e l s s s e n t fi l a c i s y h p s i s o r o p o e t s o n o i t c n u f l a c i s y h p : d e t s i l s a n o i t i d n o c n o i t a u p o p b u s l r o f e r a s e m o c t u o * l a c i t i r c t h g e w i , l o r t n o c t h g e w i , e g n a h c t h g e w i , i n a g t h g i e w y t i s o p d a i e c n a n e t n a m i i t h g e w d n a s u t a t s t h g i e w , y t i l i b a t s . -g n i k a m - n o i s i c e d o t l a c i t i r c t o n t u b , t n a t r o p m i s i t a h t e m o c t u o n a : e m o c t u o t n a t r o p m i . -i g n k a m - n o i s i c e d o t l a c i t i r c s i t a h t e m o c t u o n a : e m o c t u o l a c i t i r c ; r u o i v a h e b y r a t n e d e s , b s ; e s a e s i d s n o s n k r a p i , d p ; y t i v i t c a l a c i s y h p , a p ; s i s o r e l c s l r a u c s u m , s m ; n o i s s e r p e d l a c i n i l c j r o a m , d c m ; y t i l i b a s i d l a u t c e l l e t n i , d i ; n o i s n e t r e p y h , t h l ; e s a e s i d r a u c s a v o d r a c i , d v c ; r e d r o s i d y t i v i t c a r e p y h t i c fi e d n o i t n e t t a , d h d a i . -s e t e b a d 2 e p y t , d 2 t ; s r o v i v r u s e k o r t s n i , k t s ; y r u n j i d r o c l a n p s i , i i c s ; a n e r h p o z i h c s , h c s s w e i v e r e c n e d i v e s e n i l e d u g i l l a b o g 0 2 0 2 e h t n i d e s s e r d d a l s p u o r g n o i t a u p o p y b ) r e d r o l a c i t e b a h p a n i ( l s e m o c t u o h t l a e h f o y r a m m u s 3 e l b a t 1454 bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 for each population group was based on an assessment across all evaluated outcomes (table 2). -the gdg prioritised all- cause mortality and cardiovascular mortality as the most critical outcomes, followed by other clinical outcomes (eg, falls, depres- sion, cognition, health- related quality of life, etc), then interme- diate outcomes (eg, cardiometabolic markers, other metabolic markers) as well as physical activity risk and harms. -where there was a lack of subpopulation- specific evidence, the evidence for the general population was extrapolated but downgraded due to indirectness, when appropriate. -the gdg came to consensus on each recommendation as well as the strength of recommenda- tion ratings and voting was not required. -as required by the who process for guideline development, the draft guidelines were externally reviewed by seven indepen- dent reviewers, who provided feedback on the scientific evidence, its interpretation and the content of the guidelines. -in addition, the draft guidelines and the evidence profiles were made avail- able to the public and stakeholders, and feedback was sought through a global online consultation conducted between march and april 2020 and that received over 400 contributions. -these inputs from scientists, practitioners and the general public were collated and used by the gdg to finalise the guidelines. -these were approved by the who guidelines review committee in august 2020. the 2020 guidelines on physical activity and sedentary behaviour the final recommendations on physical activity and sedentary behaviour for each population group are summarised in table 4. for all populations, doing some physical activity is better than doing none. -if individuals are not currently meeting these recom- mendations, doing some physical activity will bring benefits to health. -individuals should start with small amounts of physical activity and gradually increase frequency, intensity and dura- tion over time. -the gdg concluded that the benefits of doing physical activity and limiting sedentary behaviour outweighed the potential harms. -any potential harms may be managed by a gradual increase in the amount and intensity of physical activity. -pre- exercise medical clearance is generally unnecessary. -indi- viduals who are not currently regularly active and have no contraindications can be recommended to commence and grad- ually increase levels and intensity of physical activity without a medical clearance. -an individual who is habitually engaging in moderate- intensity activity can gradually increase to vigorous intensity activity without needing to consult a healthcare provider. -those who develop new symptoms when increasing their levels of activity should consult a healthcare provider. -these guidelines are for the general population and do not address the benefits and harms experienced by athletes under- taking the types and amounts of activity necessary to improve performance- related fitness for participation in competition. -the evidence supporting each of the updated or new recom- mendations is summarised for each group . -further details, including a more detailed narrative summary of evidence and the evidence profile tables summarising the evidence used for all recommendations, are available from who.5 recommendations for children and adolescents (5 17 years) the evidence affirmed that physical activity in children and adolescents is associated with improved physical, mental and cognitive health outcomes. -many of the benefits of physical activity are observed with an average of 60 min of moderate- to- vigorous physical activity (mvpa) daily, although physical guidelines activity beyond 60 min of mvpa daily provide additional health benefits. -there was insufficient evidence to determine whether specific health benefits vary by type or domain of physical activity. -the evidence showed clearly that increased time in aerobic mvpa increases cardiorespiratory fitness and that increased muscle- strengthening activities increases muscular fitness, with some evidence showing incremental benefits of doing both. -one notable update from the 2010 guidelines was evidence to support changing from at least 60 min to an average of 60 min of mvpa per day as this was deemed to more closely reflect the body of evidence and the way mvpa has been measured. -the physical activity recommendation was rated as strong based on overall moderate certainty evidence. -the evidence indicated that greater time spent in sedentary behaviour is related to adverse health outcomes. -the association between sedentary behaviour and adverse health outcomes is generally stronger for television viewing or recreational screen time as the specific exposure vari- able than for total sedentary time in youth. -there was, however, insufficient evidence to set a precise threshold (or cut- off ) for the amount of sedentary or recreational screen time. -the seden- tary behaviour recommendation was rated as strong based on low certainty evidence. -recommendations for adults (18 64 years) the evidence reaffirms that all adults should regularly under- take physical activity and that some physical activity is better than none. -the adult guidelines include strong recommenda- tions based on overall moderate- certainty evidence on weekly volumes of aerobic and muscle- strengthening physical activity. -many of the benefits of physical activity are observed within average weekly volumes of 150 300 min of moderate intensity or 75 150 min of vigorous intensity, or an equivalent combi- nation of mvpa. -the weekly range of recommended aerobic activity volume is a notable difference compared with the 2010 who recommendations that only specified minimum weekly thresholds. -mvpa bouts of any duration now count towards these recommendations, reflecting new evidence to support the value of total physical activity volume, regardless of bout length.16 this recommendation differs from the requirement of bouts of at least 10 min in the previous who 2010 guidelines. -there is moderate- certainty evidence of a curvilinear dose- response association between physical activity volume and some health outcomes, such as all- cause and cardiovascular disease (cvd) mortality, and incident cancer and diabetes. -health bene- fits occur with levels of physical activity below the recommen- dations, supporting the statement that some physical activity is better than none. -more physical activity is better, although the relative benefits tend to diminish at higher levels of phys- ical activity. -however, it is not possible to specify the physical activity levels where diminishing returns begin. -for this reason, the new recommendation that aerobic physical activity volumes higher than 300 min of moderate- intensity activity per week, or 150 min of vigorous- intensity activity per week have addi- tional health benefits, is rated as conditional. -beyond aerobic physical activity, additional health benefits will occur through participation in muscle- strengthening activities at moderate or greater intensity on 2 or more days a week, a strong recommen- dation supported by moderate- certainty evidence. -there was no evidence to support a dose- response association with higher volumes of muscle- strengthening activities. -there was insufficient evidence to determine whether specific health benefits vary by type or domain of physical activity. -1455 bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 guidelines table 4 summary of the who guidelines on physcial activity and sedentary behaviour. -these public health guidelines are for all populations across the age groups from 5 years of age and above, irrespective of gender, cultural background or socioeconomic status and are relevant for people of all abilities. -those with chronic medical conditions and/or disability and pregnant and postpartum women should try to meet these recommendations where possible and as able. -physical activity sedentary behaviour children and adolescents (aged 5 17 years), including those living with disability adults (aged 18 64 years) including those with chronic conditions and those living with disability in children and adolescents, physical activity confers benefits for the following health outcomes: physical fitness (cardiorespiratory and muscular fitness), cardiometabolic health (blood pressure, dyslipidaemia, glucose and insulin resistance), bone health, cognitive outcomes (academic performance, executive function) and mental health (reduced symptoms of depression) and reduced adiposity. -it is recommended that: children and adolescents should do at least an average of 60 min/day of moderate- to- vigorous intensity, mostly aerobic, physical activity, across the week; vigorous- intensity aerobic activities, as well as those that strengthen muscle and bone should be incorporated at least 3 days a week. -strong recommendation in adults, physical activity confers benefits for the following health outcomes: all- cause mortality, cardiovascular disease mortality, incident hypertension, incident type 2 diabetes, incident site- specific cancers,mental health (reduced symptoms of anxiety and depression), cognitive health and sleep ; measures of adiposity may also improve. -it is recommended that: all adults should undertake regular physical activity; adults should do at least 150 300 min of moderate- intensity aerobic physical activity, or at least 75 150 min of vigorous- intensity aerobic physical activity, or an equivalent combination of moderate- intensity and vigorous- intensity activity throughout the week for substantial health benefits; adults should also do muscle- strengthening activities at moderate or greater intensity that involve all major muscle groups on 2 or more days a week, as these provide additional health benefits. -strong recommendation adults may increase moderate- intensity aerobic physical activity to >300 min, or do >150 min of vigorous- intensity aerobic physical activity, or an equivalent combination of moderate- intensity and vigorous- intensity activity throughout the week for additional health benefits (when not contraindicated for those with chronic conditions). -conditional recommendation in children and adolescents, higher amounts of sedentary behaviour are associated with detrimental effects on the following health outcomes: fitness and cardiometabolic health, adiposity, behavioural conduct/pro- social behaviour and sleep duration. -it is recommended that: children and adolescents should limit the amount of time spent being sedentary, particularly the amount of recreational screen time. -strong recommendation in adults, higher amounts of sedentary behaviour are associated with detrimental effects on the following health outcomes: all- cause mortality, cardiovascular disease mortality and cancer mortality and incidence of cardiovascular disease, type 2 diabetes and cancer. -it is recommended that: adults should limit the amount of time spent being sedentary. -replacing sedentary time with physical activity of any intensity (including light intensity) provides health benefits; to help reduce the detrimental effects of high levels of sedentary behaviour on health, adults should aim to do more than the recommended levels of moderate- to- vigorous physical activity. -strong recommendation older adults (aged 65 years and older) including those with chronic conditions and those living with disability in older adults, physical activity also helps prevent falls and falls- related injuries and declines in bone health and functional ability. -it is recommended that: as for adults, plus as part of their weekly physical activity, older adults should do varied as for adults strong recommendation multicomponent physical activity that emphasises functional balance and strength training at moderate or greater intensity on 3 or more days a week, to enhance functional capacity and to prevent falls. -strong recommendation in women, physical activity during pregnancy and the postpartum period confers benefits for the following maternal and fetal health outcomes: reduced risk of pre- eclampsia, gestational hypertension, gestational diabetes, excessive gestational weight gain, delivery complications and postpartum depression and no increase in risk of stillbirth, newborn complications or adverse effects on birth weight. -it is recommended that all pregnant and postpartum women without contraindication should: undertake regular physical activity throughout pregnancy and post partum; do at least 150 min of moderate- intensity aerobic physical activity throughout the week for substantial health benefits; incorporate a variety of aerobic and muscle- strengthening activities. -adding gentle stretching may also be beneficial. -in addition: women who, before pregnancy, habitually engaged in vigorous- intensity aerobic activity or who were physically active can continue these activities during pregnancy and the postpartum period. -strong recommendation pregnant and postpartum women 1456 pregnant and postpartum women should limit the amount of time spent being sedentary. -replacing sedentary time with physical activity of any intensity (including light intensity) provides health benefits. -strong recommendation continued bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 guidelines table 4 continued these public health guidelines are for all populations across the age groups from 5 years of age and above, irrespective of gender, cultural background or socioeconomic status and are relevant for people of all abilities. -those with chronic medical conditions and/or disability and pregnant and postpartum women should try to meet these recommendations where possible and as able. -physical activity sedentary behaviour additional explanatory and practical notes: some physical activity is better than none. -if not currently meeting these recommendations, doing some physical activity will bring benefits to health. -start with small amounts of physical activity and gradually increase frequency, intensity and duration over time. -pre- exercise medical clearance is generally unnecessary for individuals without contraindications prior to beginning light- intensity or moderate- intensity physical activity not exceeding the demands of brisk walking or everyday living. -it is important to provide all children and adolescents with safe and equitable opportunities and encouragement to participate in physical activities that are appropriate for their age and ability, that are enjoyable, and that offer variety. -older adults should be as physically active as their functional ability allows and adjust their level of effort for physical activity relative to their level of fitness. -when not able to meet the recommendations, adults with chronic conditions should aim to engage in physical activity according to their abilities. -adults with chronic conditions may wish to consult with a physical activity specialist or healthcare professional for advice on the types and amounts of activity appropriate for their individual needs, abilities, functional limitations/complications, medications and overall treatment plan. -if pregnant and postpartum women are not currently meeting these recommendations, doing some physical activity will bring benefits to health. -they should start with small amounts of physical activity and gradually increase frequency, intensity and duration over time. -pelvic floor muscle training may be performed on a daily basis to reduce the risk of urinary incontinence. -additional on safety considerations when undertaking physical activity for pregnant women are: avoid physical activity during excessive heat, especially with high humidity; stay hydrated by drinking water before, during and after physical activity; avoid participating in activities which involve physical contact, pose a high risk of falling or might limit oxygenation (such as activities at high altitude, when not normally living at altitude); avoid activities in supine position after the first trimester of pregnancy; pregnant women considering athletic competition or exercising significantly above the recommended guidelines should seek supervision from a specialist healthcare provider; pregnant women should be informed by their healthcare provider of the danger signs for when to stop, or limit physical activity and to consult a qualified healthcare provider immediately if they occur. -return to physical activity gradually after delivery and in consultation with a healthcare provider in the case of delivery by caesarean section. -there are no major risks to people living with disability engaging in physical activity when it is appropriate to an individual s current activity level, health status and physical function and the health benefits accrued outweigh the risks. -people living with disability may need to consult a healthcare professional or other physical activity and disability specialist to help determine the type and amount of activity appropriate for them. -physical activity accrued at work, leisure, home or during trans- portation count towards the recommended amounts. -the reviewed evidence on sedentary behaviour and health outcomes in adults provided support that all adults should limit the amount of time spent sedentary. -there was moderate- certainty evidence that the relationship of sedentary behaviour with all- cause and cvd mortality varies by amount of physical activity. -for other outcomes, the evidence was insufficient. -new evidence on the interdependent relationship between sedentary behaviour and physical activity underpinned the additional guid- ance that recommends increased levels of mvpa in the context of high levels of sedentary time. -however, there was insuffi- cient evidence to specify quantitative thresholds of sedentary behaviour, to determine whether specific health benefits vary by type or domain of sedentary behaviour or to determine the influ- ence of frequency and duration of breaks in sedentary behaviour on health outcomes. -recommendations for older adults (65 years and above) the evidence reviewed on physical activity and sedentary behaviour for adults also applied to older adults for the common set of critical health outcomes (table 3), because the majority of studies employed no upper age limit and therefore included adults over the age of 65 years. -additional health- related outcomes were reviewed because of their significant importance to older adults: 1) falls; 2) fall- related injuries; 3) physical func- tion; 4) frailty and 5) osteoporosis. -new high- certainty evidence demonstrates an inverse dose- response relationship between volume of aerobic physical activity and risk of physical functional limitations in older adults. -high- certainty evidence demonstrates that balance and func- tional exercises reduce the rate of falls and that engaging in a range of different types of physical activity can help to improve a wide range of elements of physical function. -moderate- certainty evidence indicates that the risk of fall- related injury may be reduced with multicomponent physical activity (combinations of balance, strength, endurance, gait and physical function training). -as such it is recommended that as part of their weekly physical activity, older adults should do varied multicomponent physical activity at moderate or greater intensity on 3 or more days a week in order to enhance functional capacity and prevent falls. -one notable update from the previous 2010 guidelines is that regular participation in this type of physical activity is recommended for all older adults rather than specifically those with poor mobility. -moderate- certainty evidence indicates that programmes involving multiple exercise types probably have significant effects on bone health and osteoporosis prevention. -because the evidence reviewed for sedentary behaviour in adults included those over the age of 65 years, the adult recommenda- tions were deemed to also apply for this population group. -recommendations for pregnant and postpartum women there is high- certainty evidence that physical activity during pregnancy is associated with reduced gestational weight gain and reduced risk of gestational diabetes mellitus in pregnant women with overweight or obesity. -there is high- certainty to moderate- certainty evidence that the incidence of gestational hypertension is no different between pregnant women who exercise and those receiving standard antenatal care. -among pregnant women with overweight or obesity, there is low- certainty to moderate- certainty evidence to suggest no increased risk of low birth weight, small for gestational age or large for gestational age babies between women who are physically active and those in standard antenatal care. -there is 1457 bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 guidelines moderate- certainty evidence of a small, but significant, reduced risk of preterm birth in mothers who engaged in vigorous phys- ical activity. -similarly, among pregnant women with overweight or obesity there was no significant difference in the risk of preterm birth between those who were physically active and those in standard antenatal care. -available evidence from inter- vention trials combining both aerobic and muscle- strengthening physical activity support the recommendation for regular strength training to be included for pregnant and postpartum women. -no direct evidence was reviewed on sedentary behaviour for this subpopulation; however, the gdg reviewed the evidence for general populations and concluded it was applicable. -therefore, the sedentary behaviour recommendations for adults are extrap- olated to pregnant and postpartum women and the certainty of the evidence downgraded for indirectness. -recommendations for people living with chronic conditions physical activity is considered safe for adults living with the selected chronic conditions without contraindications, and the benefits generally outweigh the risks. -evidence was reviewed for the following chronic conditions: cancer, hypertension, type 2 diabetes and hiv. -greater physical activity is related to improved health outcomes in people living with coronary heart disease. -among adults with type 2 diabetes, there is high- certainty evidence that physical activity is associated with decreased risk of cvd mortality and decreased levels of haemoglobin a1c, blood pressure, body mass index and lipids. -among adults with hypertension, there is high- certainty evidence that physical activity decreases risk of progression of cardiovascular disease and reduces blood pressure, while there is moderate- certainty evidence that physical activity reduces the risk of cvd mortality. -high- certainty evidence shows that physical activity performed postcancer diagnosis is related to lower risks of mortality from all causes and mortality from cancer in female breast cancer survivors and colorectal cancer survivors. -given that large numbers of people are currently living with hiv and that antiretroviral therapy has become effective and widely available, hiv is now considered a chronic condi- tion. -thus, evidence on people living with hiv are included in these guidelines for the first time. -there was moderate- certainty evidence that in people living with hiv, physical activity enhances health- related quality of life, maximal oxygen consumption, exercise tolerance, general health and physical functioning. -there was moderate- certainty to high- certainty evidence that regular physical activity did not result in signifi- cant change in viral load, cd4+ count or disease progression, and as such, persons living with hiv are not adversely affected by physical activity. -there was moderate- certainty to high- certainty evidence that physical activity decreased symptoms of anxiety and depres- sion. -in addition, there was moderate- certainty to high- certainty evidence that physical activity was associated with a reduction in body fat percentage and an increase in lean body mass, but not waist circumference or body mass index. -although there was no direct evidence on sedentary behaviour for these subpopulations, the gdg considered and concluded that the evidence for general populations was applicable. -therefore, the sedentary behaviour recommenda- tions for adults were extrapolated to adults living with these chronic diseases and the certainty of the evidence downgraded for indirectness. -1458 recommendations for people living with disability evidence was reviewed for the following health conditions: multiple sclerosis, spinal cord injury, intellectual disability, parkinson s disease, stroke, major clinical depression, schizo- phrenia and attention deficit hyperactivity disorder (adhd). -the following health outcomes were examined: comorbidity, physical functioning, cognition and quality of life, but not all outcomes were assessed for each condition. -this evidence was considered together with the evidence for those without disability and the resulting recommendations were extrapolated to be applicable to people with disability in general. -physical activity is considered safe and beneficial for people living with disability without contraindications, and there are no major risks when it is appropriate to an individual s current activity level, health status and physical functioning level. -adults living with disability may need to consult a healthcare profes- sional or other physical activity and disability specialist to help determine the type and amount of activity appropriate for them. -in people with spinal cord injury, low- certainty and moderate- certainty evidence suggests physical activity reduces shoulder pain and improves vascular function in paralysed limbs. -insuf- ficient evidence was available to determine the relationship between physical activity and comorbid conditions in individuals with intellectual disability or multiple sclerosis. -there is high- certainty evidence showing that physical activity can improve functioning in people with multiple sclerosis, spinal cord injury and a history of stroke. -for people with intellectual disability or parkinson s disease, this evidence is of low certainty and high certainty, respectively. -limited evidence was available for the relationship between physical activity and quality of life in people with multiple sclerosis, spinal cord injury and intellectual disability. -however, for people with schizophrenia and major clinical depression there was moderate- certainty evidence for beneficial effects on quality of life. -moderate- certainty evidence indicates that physical activity can have beneficial effects on cognition in people with multiple sclerosis, parkinson s disease, a history of stroke, adhd and major clinical depression. -for people with schizophrenia this evidence was of high certainty. -the evidence on the associations between sedentary behaviour and health outcomes in children, adolescents and adults living with disability was derived from literature reviewed for the general populations. -the gdg concluded that these recommen- dations could be extrapolated to children, adolescents, adults and older adults living with disability, according to their specific ability, but downgraded the certainty of the evidence due to indi- rectness. -the gdg agreed that benefits accrued from reducing sedentary time and gradually increasing physical activity where possible, depending on ability. -in the case of those living with disability, especially wheelchair users or those with low mobility, it is important to note that it is possible to avoid sedentary behaviour while sitting or lying by doing light- intensity or high- intensity activities that do not involve the lower extremities. -discussion the updated who 2020 guidelines on physical activity and sedentary behaviour5 provide clear, evidence- based, recommen- dations on how much physical activity provides health benefits for different population groups and on the potential risks of sedentary behaviours. -these guidelines should be used to inform global, regional and national policy actions and investment, as well as to guide and strengthen national health behaviour surveillance systems that track progress towards national and global targets.1 the development of these new guidelines bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 identified important areas requiring further research and thus also identified research priorities for the academic and research community. -what remains the same? -the evidence confirms the value of participating in regular physical activity to achieve health benefits across all ages and abilities. -further it supports key messages that some physical activity is better than none and that more is better for optimal health outcomes. -more specifically, the evidence reaffirms all adults should undertake regular physical activity and should aim to achieve at least 150 min of moderate- intensity, or 75 min of vigorous- intensity aerobic physical activity per week, or some equivalent combination of moderate- intensity and vigorous- intensity aerobic physical activity. -among children and adoles- cents, an average of 60 min/day of moderate- to- vigorous intensity physical activity across the week (most of which should be aerobic), leads to health benefits. -furthermore, the guide- lines continue to reinforce the value of muscle- strengthening activity for all adults and children. -the key physical activity- specific recommendations above remain largely unchanged from 2010 and are consistent with other recently developed physical activity guidelines from several countries.13 17 22 what is new? -there are a few important differences in the new guidelines that should be highlighted for each age group. -first, in adults, the previous stipulation that physical activity should be accumu- lated in at least 10 min bouts has been removed. -this change reflects the accumulated evidence from cohort studies, which shows physical activity of any bout duration is associated with improved health outcomes, including all- cause mortality.16 23 second, these updated guidelines for adults now specify a target range of 150 300 min of moderate- intensity and 75 150 min of vigorous- intensity physical activity, compared with the previous guidelines that focused on achieving at least 150 min of moderate- intensity or 75 min of vigorous- intensity activity per week. -this change acknowledges that there is a range of physical activity which captures the maximal risk reductions for health outcomes associated with physical activity and going beyond this range does not appreciably further decrease the risk of major outcomes such as all- cause or cvd mortality. -third, with respect to older adults, the recommendation regarding multicomponent physical activity that emphasises functional balance and strength training to enhance functional capacity and prevent falls now applies to all older adults rather than specifically those with poor mobility. -this change acknowledges the large volume of evidence demon- strating unequivocal beneficial effects of this physical activity type on the functional capacity and risk of falls in older people with a range of functional abilities. -there was also one key change in the new recommendations for children and adolescents. -specifically, the updated recom- mendation is now to do at least an average of 60 min/day of mvpa rather than the previously stated accumulate 60 min of physical activity daily . -although this might appear to be a subtle difference, the change better reflects the scientific evidence as most studies reported associations between an average daily value of physical activity rather than an accumulation of 60 min on each and every day of the week. -the new recommendation that sedentary behaviour should be limited across all groups is an important addition to these new global guidelines since 2010 and is in line with other recent country- level guidelines19 20 that generally support the guidelines notion of moving more and reducing sedentary time ( sitting less for ambulatory people). -although specifying a quantitative threshold on the amount of sedentary behaviour was strongly considered, there was insufficient evidence. -furthermore, varia- tions in how sedentary time was measured, and that a threshold would likely vary by health outcome, by level of physical activity and by population subgroups, made quantifying upper time limits difficult to ascertain. -the recommendation to limit sedentary behaviour was qual- ified with an acknowledgement that replacing sedentary time with any intensity of physical activity (including light intensity) has health benefits. -this recommendation was based first on the juxtaposed evidence of lower levels of time spent in sedentary behaviours being beneficial for health even among those with modest levels of mvpa, and on the emerging, largely cross- sectional evidence, from replacement studies (ie, isotemporal substitution) demonstrating these effects more directly. -second, there was evidence of effect modification between sedentary time and mvpa, which supported the development of a second recommendation emphasising the benefits of undertaking more than the recommended levels of mvpa to help reduce the detrimental effects of high levels of sedentary behaviour. -the important practical application of this recommendation is to encourage the promotion of multiple approaches to limiting the negative health outcomes associated with high levels of sedentary time. -this includes recommending individuals reduce their time spent in sedentary behaviours or increase their mvpa to help offset the negative impact, or some combination of both strate- gies. -given that time spent in sedentary behaviours at work, for transport or for recreation appears to be overtaking time spent in more healthy physical activity behaviours during waking hours, the gdg deemed it important to attend to both physical activity and sedentary time and, therefore, to recommend a balance of these behaviours for better health. -although the evidence on health benefits of breaking up sedentary time and types of sedentary behaviours was reviewed, the gdg considered that there was insufficient evidence to provide specific quantified recommendations. -an additional issue related to the sedentary recommendations was the decision to opt specifically for the use of the term seden- tary behaviour instead of sitting , which has been commonly used in several national guidelines. -this wording choice was deliberate and made to reflect the overarching agenda of these new guidelines to be inclusive of people living with disability and therefore to emphasise options for reducing sedentary behaviour among wheelchair users and those with low mobility, where prolonged sitting may be unavoidable. -for such people, sedentary time can be minimised through physical activity while remaining seated. -guidelines for special groups key considerations the development of recommendations on physical activity and sedentary behaviours specifically for key populations, namely, people living with disability and chronic conditions, as well as for pregnant and postpartum women, addressed important gaps in global health policy. -these new recommendations affirm that physical activity is feasible for these groups; and provides for the first- time global science- based recommendations to inform the development of population- based initiatives to improve health outcomes for these population groups. -in particular, these recommendations for people living with chronic disease and disability should stimulate increased attention in policy, surveil- lance, investment and research aligned to the agenda of inclusion 1459 bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 guidelines as called for in the sustainable development goals24 as well as in the convention on the rights of people living with disability.25 in undertaking this new work there were however several limitations. -specifically, the association between physical activity and health outcomes was only reviewed for selected chronic conditions and disabilities and there was limited evidence to inform on the optimal type, frequency or duration of activity by health condition. -due to the lack of direct evidence, consid- erable extrapolation was needed to develop the recommenda- tions on physical activity and the recommendations on sedentary behaviour relied entirely on the evidence from the general popu- lation. -nonetheless, the gdg concluded the strong recommen- dations for this population reflect the balance between desirable and undesirable consequences and send an important message to support the inclusion of people living with disability in physical activity population health initiatives. -using these guidelines developing global guidelines is not an end in itself. -the 2020 who guidelines provide a set of evidence- based physical activity and sedentary behaviour recommendations that national govern- ments can adopt, thus removing the need for countries to use limited resources to undertake their own scientific reviews and expert consensus process. -this issue is particularly important for lmics where resources may be limited. -during adoption of these global guidelines, national policymakers are encouraged to consider their national context and factors such as culture, ethnic diversity, existing social norms and the current provision for physical activity promotion within healthcare services as well as primary prevention, to inform adaptations and dissemination of the guidelines. -the existence of guidelines, in isolation, is unlikely to lead to increases in population levels of physical activity. -it is crit- ical that they are supported by coordinated dissemination to key audiences and a sustained national public education communi- cation strategy. -furthermore, communication activities must be combined with implementation of setting specific policy actions to support behaviour change. -how to optimise the impact of physical activity guidelines through effective communication strategies is explored in a separate paper in this issue.26 in 2018, the new gappa 2018 2030 set a target to reduce physical inactivity by 15% by 2030 and outlined 20 recom- mended policy actions and interventions.1 these included recommending all countries combine sustained national public education and awareness campaigns with the integration of phys- ical activity counselling programmes into primary and secondary healthcare. -other recommendations included the creation of appropriate and supportive environments for physical activity for all population groups and increasing opportunities for phys- ical activity in schools, workplaces, cities and communities and as a form of safe and sustainable transport. -these 2020 global guidelines provide focus to the overall goal of national policy and support expanding the scope of actions to include additional groups, such as people living with disability, chronic conditions and women who are pregnant or post partum. -national policy will need to offer a route to the development of appropriate programme delivery and practice that recognises community needs and the diversity of groups and contexts and seeks to reduce existing disparities in access to and engagement in physical activity. -the inclusion of global recommendations on muscle strengthening activities is not new in these updated guidelines, but the gdg implicitly recognised their increasing importance due to an expanding evidence base. -1460 promotion of muscle strengthening and falls prevention activi- ties have been largely forgotten or ignored in the past27 28 and in most countries a much greater focus on this is now required for policy and practice. -implications of these guidelines for health surveillance these updated guidelines have several implications for future population monitoring and research. -first, currently used surveillance instruments and/or protocols will need adaptation to align with the key changes made in these updated guidelines. -second, national population surveillance systems will need to be extended to include and track trends in key populations such as children aged 5 10 years, pregnant and postpartum women, older adults and persons living with disability or chronic condi- tions. -third, monitoring systems should be strengthened to track trends in muscle- strengthening exercises, which are of increasing importance with an ageing demographic in many countries. -fourth, as many countries are reliant on self- reported methods, which have well- established limitations,29 there is a need to accel- erate advancements in sensor technology to ensure it provides a practical and affordable approach to assessing physical activity and sedentary behaviours. -the potential of the new guidelines for advancing surveillance as well as the need for development key messages these new 2020 who guidelines on physical activity and sedentary behaviour provide evidence- based public health recommendations concerning the amount and types of physical activity that offer significant health benefits and mitigate health risks. -they update and replace the previous 2010 who recommendations on physical activity. -the guidelines address children over the age of 5 years, adults, older adults and, for the first time, include specific recommendations for pregnant and postpartum women and people living with chronic conditions or disability. -for all populations, the benefits of doing physical activity and limiting sedentary behaviour outweighed the potential harms. -risks can be managed by gradual increase in the amount and intensity of physical activity. -some physical activity is better than none for those not currently meeting these recommendations, individuals should start with small amounts of physical activity and gradually increase frequency, intensity and duration over time. -countries are encouraged to adopt and disseminate these new global guidelines to key audiences, and use them as the basis for sustained national public education communication campaigns responding to their national context and factors such as culture, ethnic diversity and social norms. -these new guidelines should inform national policy and actions to promote physical activity and reduce sedentary behaviours as well as to align national health behaviour surveillance systems that track progress towards national and global targets. -important evidence gaps remain and more research is needed on the dose- response relationship between volume and/or intensity of physical activity and health outcomes, particularly in people living with disability, and further evidence from low- income and middle- income, disadvantaged or underserved communities. -bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 of device- based approaches to inform a new generation of guide- lines is discussed by troiano et al.30 key knowledge gaps despite the large quantity of data relating physical activity, and increasingly sedentary behaviours, to health outcomes across the life- span, the gdg discussions revealed important evidence gaps, which should be prioritised to inform future guidelines. -the most common need cited is more research on the dose- response relationship between volume and/or intensity of phys- ical activity and health outcomes. -such information is key to establishing minimal effective doses and maximum safety thresh- olds of physical activity for different population subgroups. -there also remains limited evidence from lmics and econom- ically disadvantaged or underserved communities and many studies are not designed or powered to test for effect modifica- tion by various sociodemographic factors. -such information is important for making more specific public health recommenda- tions and reducing health disparities in more vulnerable sectors of the population. -further details on the research gaps arising from these new guidelines can also be found elsewhere.31 conclusions these new, updated who guidelines on physical activity and sedentary behaviour, together with the who guidelines for under 5 years of age,6 provide recommendations on physical activity and sedentary behaviour for individuals across the whole age spectrum and address a long- lasting gap with the inclusion of key populations for the first time. -collectively, the recommen- dations affirm the importance of regular aerobic and muscle- strengthening physical activity and reduction in sedentary behaviours. -benefits accrue from doing any amount of physical activity and this applies to people of all ages and abilities. -there are significant health gains and cost savings to health systems if countries adopt these guidelines and direct efforts and resources to implementation of programmes and policy to enable achieve- ment of the 2030 gappa target set out in the global action plan on physical activity.1 benefits extend also beyond the health sector as mounting evidence across diverse fields shows the inter- connected social, economic and environmental impacts of more physically active populations. -now, it is time to work to ensure and support the adoption and implementation of these new global guidelines for a healthier, more active future worldwide. -author affiliations 1physical activity unit, department of health promotion, world health organization, geneva, switzerland 2school of human sciences, the university of western australia, perth, western australia, australia 3health promotion center, riyadh, saudi arabia 4centre for health research, university of southern queensland, toowoomba, queensland, australia 5age institute, helsinki, finland 6public health evaluation and projection unit, finnish institute for health and welfare, helsinki, uusimaa, finland 7college of health solutions, arizona state university, phoenix, arizona, usa 8department of movement and sports sciences, ghent university, belgium 9institute of technology tralee, tralee, co kerry, ireland 10unesco chair of transforming the lives of people with disabilities, their families and communities, through physical education, sport, recreation and fitness 11healthy active living and obesity research group, children s hospital of eastern ontario research institute, department of pediatrics, university of ottawa, ottawa, ontario, canada 12school of health and life sciences, glasgow caledonian university, glasgow, uk 13departments of medicine, and medical informatics & clinical epidemiology, oregon health & science university, portland, oregon, usa 14mrc epidemiology unit, school of clinical medicine, university of cambridge, cambridge, uk guidelines 15baker heart and diabetes institute, melbourne, vic 3004, australia; diabetes research centre, university of leicester, leicester general hospital, leicester, uk 16department of exercise and nutrition science, milken institute school of public health, the george washington university, washington, dc, usa 17department of sport medicine, norwegian school of sport science, oslo, norway 18department of chronic diseases and ageing, norwegian institute of public health, oslo, norway 19nicm health research institute, western sydney university, penrith, new south wales, australia 20division of psychology and mental health, university of manchester, manchester, uk 21department of cancer epidemiology and prevention research, cancercontrol alberta, alberta health services, calgary, alberta, canada 22centre for public health, queen s university belfast, belfast, uk 23department of non- commuicable diseases, ministry of health, nairobi, kenya 24centre for exercise, nutrition & health science, school for policy studies, university of bristol, bristol, uk 25population and public health sciences, pennington biomedical research center, baton rouge, louisiana, usa 26research centre for health through physical activity, lifestyle and sport, division of exercise science and sports medicine, department of human biology, faculty of health sciences, university of cape town, cape town, south africa 27department ofepidemiology and preventive medicine, university of regensburg, germany 28faculty of medicine and health sciences, norwich medical school, university of east anglia faculty of medicine and health sciences, uk 29profith (promoting fitness and health through physical activity) research group, department of physical education and sports, faculty of sport sciences, research institute of sport and health, university of granada, spain 30sports and exercise medicine unit and department of allied health sciences, faculty of medicine, university of colombo, colombo, sri lanka 31charles perkins centre, university of sydney, school of health sciences, faculty of medicine and health, the university of sydney, sydney, new south wales, australia 32institute for musculoskeletal health, the university of sydney, sydney, new south wales, australia 33epidemiology and genomics research program, national cancer institute, bethesda, maryland, usa 34department of public and occupational health, amsterdam public health research institute, amsterdam vrije universiteit, amsterdam, the netherlands 35prevention research collaboration, school of public health, the university of sydney, sydney, new south wales, australia 36national department of health, port moresby, papua new guinea twitter matthew p buman @mbuman, ulf ekelund @ulf_ekelund, estelle lambert @vickilambert, karen milton @karenmilton8, emmanuel stamatakis @m_ stamatakis and anne tiedemann @annetiedemann1 acknowledgements the work and contributions to support this work from the following are gratefully acknowledged: the systematic reviews of evidence prepared for 2018 us physical activity guidelines advisory committee scientific report to the secretary of us department of health and human services were updated thanks to additional literature searches conducted by kyle sprow (national cancer institutes, national institutes of health, maryland, usa). -summaries of evidence and grade tables were prepared by carrie patnode and michelle henninger (the kaiser foundation hospitals, center for health research, portland, oregon, usa). -additional reviews of evidence were led by c sherrington (institute for musculoskeletal health, school of public health, the university of sydney, sydney, australia; s mabweazara (research centre for health through physical activity, lifestyle and sports medicine, faculty of health sciences, university of cape town, cape town, south africa) and l leach (department of sport, recreation and exercise science, faculty of health sciences, university of the western cape, cape town, south africa); e verhagen and p coenen (department of public and occupational health at amsterdam university medical centre, amsterdam, the netherlands). -erin dooley (national cancer institutes, national institutes of health, maryland, usa) kindly provided support for the referencing and proof- reading of the manuscript. -the many research assistants that supported members of the gdg in reviewing the evidence and preparation of draft evidence summaries. -contributors all authors were involved in conceptualising the paper, drafting, revisions and editing and final review. -fb led the overall development of the paper. -jw and fb led the drafting of the method section. -all authors reviewed and approved the final paper. -funding the public health agency of canada and the government of norway provided financial support, without which this work could not have been completed. -competing interests none declared. -1461 bull fc, et al. -br j sports med 2020;54:1451 1462. doi:10.1136/bjsports-2020-102955 guidelines patient and public involvement patients and/or the public were involved in the design, or conduct, or reporting, or dissemination plans of this research. -refer to the methods section for further details. -12 physical activity guidelines advisory committee. -2018 physical activity guidelines advisory committee scientific report. -washington, dc: us department of health and human services, 2018. patient consent for publication not required. -ethics approval this study was approved by the who guidelines review committee in august 2020. provenance and peer review not commissioned; externally peer reviewed. -data availability statement all data relevant to the study are included in the article. -further details, including the evidence profile tables summarising the evidence used for all recommendations, are available from who. -open access this is an open access article distributed in accordance with the creative commons attribution 4.0 unported (cc by 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the licence is given, and indication of whether changes were made. -see: https:// creativecommons. -org/ licenses/ by/ 4. -0/. -orcid ids fiona c bull http:// orcid. -org/ 0000- 0001- 8035- 4973 matthew p buman http:// orcid. -org/ 0000- 0002- 5130- 3162 jean- philippe chaput http:// orcid. -org/ 0000- 0002- 5607- 5736 sebastien chastin http:// orcid. -org/ 0000- 0003- 1421- 9348 ulf ekelund http:// orcid. -org/ 0000- 0003- 2115- 9267 russell jago http:// orcid. -org/ 0000- 0002- 3394- 0176 estelle lambert http:// orcid. -org/ 0000- 0003- 4315- 9153 karen milton http:// orcid. -org/ 0000- 0002- 0506- 2214 emmanuel stamatakis http:// orcid. -org/ 0000- 0001- 7323- 3225 richard p troiano http:// orcid. -org/ 0000- 0002- 6807- 989x references 1 world health organization. -global action plan on physical activity 2018-2030: more active people for a healthier world. -geneva: world health organization, 2018. -2 world health organization. -global recommendations on physical activity for health. -geneva: world health organization, 2010. -3 guthold r, stevens ga, riley lm, et al. -worldwide trends in insufficient physical activity from 2001 to 2016: a pooled analysis of 358 population- based surveys with 1 9 million participants. -lancet glob health 2018;6:e1077 86. 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