# Presentation: 854346

## Biobehavioral Issues Influencing Food Choices and Energy Intake

- Susan B. Roberts, PhD
- Director, Energy Metabolism Laboratory
- USDA Human Nutrition Research Center on Aging at Tufts University

## US Trend in Energy Intake 

**US Trend in Energy Intake **

**• ****In 1997, per capita energy intake was 340 kcal/d higher than 1984 and 500 kcal/d higher than in 1977**
**• ****Reported energy intake by individuals also increased since 1984, by ~ 130-190 kcal/d.**

**Notes:**
One fact from USDA food consumption data stands out from  all the information about why obesity is increasing. It concerns calories.  This graph shows per capita food supply information, with the lower line giving actual per capita calorie intakes after adjusting for estimated plate losses and so on.

What it shows is that energy intake has increased by 340 kcal/d since 1984, and this is clearly a big part of the immediate cause of our national obesity problem. The First Law of Thermodynamics teaches us that matter can neither be creased nor destroyed, so excess energy intake will be stored unless it is expended.

## Dietary and Biobehavioral Factors in Food Choices 

**and Energy Regulation**

**        **_**DIETARY PROPERTIES **_
**Macronutrients:  Physical Properties:**
***Fat                      Energy Density***
***Protein                Fiber (& type)***
***Carb (& type)     Food structure ******	******	******     ******	******     (raw vs. cooked etc)***
***                            ******Glycemic Index***

_**DIETARY PATTERNS**_
**Palatability/Taste**
**Variety within food groups**
**Food choices**
**Meal/snack patterns**
**Meal size & interval**

_**DIETARY BEHAVIOR**_
**Restraint/disinhibition**
**Social eating**
**Eating out**
**Societal norms**

**ENERGY INTAKE**

**Body Weight**

## What causes overeating and weight gain?

- Variety
- Palatability
- Restaurant and other non-home foods
- Eating behavior (restraint, disinhibition)
- Portion size, Liquid calories
- Dietary composition (fat/carbohydrate fiber, glycemic index, energy density, protein)

## Experimental Evidence for Dietary Variety Effects on Energy Intake  - Animals

- <date/time>

**Experimental Evidence for Dietary Variety Effects on Energy Intake  - Animals**

**1st author****, ****year**

**Animals**

**DV effect?**

**Magnitude**

- Le Magnen, 1956 *
- Mugford, 1977 **
- Louis-Sylvestre, 1983 **
- Rolls, 1983 **
- Triet, 1983 *
- Rogers, 1984 **
- Clifton, 1987 *
- DiBattista, 1993 *

- rats
- cats
- rats
- rats
- rats
- rats
- rats
- hamsters

- Yes
- Yes
- Yes
- Yes
- Yes
- Yes
- Yes
- Yes

- 72%
- 47%
- 46%
- 15-38%
- 50-70%
- 32%
- 26%
- 40-100%

- *  Within meal ; **  Between meal

## Experimental Evidence for Dietary Variety Effects on Energy Intake  - Humans

- <date/time>

**Experimental Evidence for Dietary Variety Effects on Energy Intake  - Humans**

**1st author****, ****year**

**Subjects**

**DV effect?**

**Magnitude**

- Pliner, 1980
- Bellisle, 1981
- Rolls, 1981a
- Rolls, 1981b
- Beatty, 1982
- Rolls, 1982
- Berry, 1985
- Speigel, 1990
- Brown, 1997

- adults
- adults
- adults
- adults
- adults
- adults
- adults
- adults
- infants

- Yes
- Yes
- Yes
- Yes
- Yes
- Yes
- Yes
- Yes
- Yes

- 22%
- 38%
- 20-33%
- 110%
- 120% (women)
- 0-14%
- 82%
- 17-31%
- 10%

**Within or Between Meal**

- W
- W
- W
- W
- W
- W
- W
- W
- B (4 d)

## Association Between Dietary Variety and Energy Intake Within Food Groups (McCrory et al. Am J Clin Nutr 1999;69:440)

**Variety (% maximum)**

**• ****Dietary variety scores over 6 months were determined by FFQ for 71 U.S. men and women (20-80 y) accurately reporting EI (********30% predicted energy requirements)**
**• ****EI within all food groups studied was significantly related to variety within the food group**

## Dietary Variety and Body Fatness in the U.S.: Multiple Regression Models(McCrory et al. 1999)

- VEGETABLES

- HIGH ENERGY DENSE GROUP

** ****Vegetable variety was inversely associated, and sweets, snacks, condiments, entrees, and carbohydrates variety was positively associated with body fatness**

** ****The Variety Ratio (ratio of vegetable to sweets, snacks, condiments, entrees, and carbohydrates variety) was significantly associated with body fatness, but % dietary fat was not**

## Association of dietary factors and physical activity with body fatness in urban Chinese adults living in Beijing (Yao et al. 2003)

**Association of dietary factors and physical activity with body fatness in urban Chinese adults living in Beijing ****(Yao et al. 2003)**

## US Trends in Food Supply Variety(McCrory et al. AJCN 1999;69:440, drawn from data in Flegal et al 1998, Gallo 1997)

**US Trends in Food Supply Variety****(McCrory et al. AJCN 1999;69:440, drawn from data in Flegal et al 1998, Gallo 1997)**

**Prevalence of overweight and obesity (%)**

**BMI (kg/m****2****)**

## What causes overeating and weight gain?

- Variety
- Palatability
- Restaurant and other non-home foods
- Eating behavior (restraint, disinhibition)
- Portion size, Liquid calories
- Dietary composition (fat/carbohydrate fiber, glycemic index, energy density, protein)

## Palatability

- In dietary surveys, the primary reason why particular foods are chosen is taste, and varied diets are probably more palatable than restricted diets.

- Cross et al, 1994
- Cross et al, 1995
- Caltabiano and Shellshear, 1998
- Glanz et al, 1998

## Palatability Effects on Blood Glucose Response to a Test Meal (Sawaya et al, 2001)

**Blood Glucose (μ/dl)**

## What causes overeating and weight gain?

- Variety
- Palatability
- Restaurant and other non-home foods
- Eating behavior (restraint, disinhibition)
- Portion size, Liquid calories
- Dietary composition (fat/carbohydrate fiber, glycemic index, energy density, protein)

## Relationship Between Frequency of Restaurant Food Consumption and Body Fatness in U.S. Adults aged 19-80(McCrory et al. Obes Res 1999;7:564) 

**Assessed by the FHCRC/Block FFQ for the past 6 months, in subjects accurately reporting EI (********30% predicted energy requirements)**
** ****Analyses are controlled for age, sex, smoking, alcohol intake, education level, and (in n=55) leisure time PAL**

## Dietary Intake in Relation to Frequency of Consuming Restaurant Food (McCrory et al. Ob Res 1999;7:564) 

- <date/time>

**Dietary Intake in Relation to Frequency of Consuming Restaurant**** ****Food**** ****(McCrory et al. Ob Res 1999;7:564)**

**Freq of consuming restaurant food****1,2**

- Total energy (MJ/d)
- (kJ/kg bw/d)
- Fat (% energy)
- Sat fat (% energy)
- Fiber (g/MJ/d)
- Alcohol (% energy)

**r**

**<4/mo**

**4-12/mo**

**>12/mo**

- 0.58 *
- 0.42 *
- 0.28 *

- 0.29 *
- -0.45 *
- 0.06

- 7.9 (1.6)
- 129 (25)
- 33 (7)

- 9.1 (2.1)
- 135 (24)
- 35 (7)

- 10.4 (2.5)
- 151 (37)
- 38 (7)

- 12 (3)
- 2.5 (0.7)
- 3.4 (5.0)

- 13 (3)
- 2.0 (0.7)
- 2.8 (4.9)

- 15 (3)
- 1.6 (0.6)
- 3.1 (4.7)

- 1 Mean (SD)         2 n = 30, 29 and 14, respectively (71 total)         **P *< 0.03

## Percentage of Daily Meals and Energy Consumed at Home and Away From Home in Americans > 2yrs old

**Source: USDA/ERS Agricultural Information Bulletin No. 750**

## What causes overeating and weight gain?

- Variety
- Palatability
- Restaurant and other non-home foods
- Eating behavior (restraint, disinhibition)
- Portion size, Liquid calories
- Dietary composition (fat/carbohydrate fiber, glycemic index, energy density, protein)

## Dietary Restraint, Disinhibition, and Hunger

- <date/time>

**Dietary Restraint, Disinhibition, and Hunger**

**Restraint - **tendency to restrict food intake to prevent weight gain/promote loss
**Disinhibition** - tendency to overeat in the presence of particular stimuli (e.g. palatable foods, alcohol, emotional distress)
**Hunger** - susceptibility to perceived body symptoms that signal the need for food

- Measured using the Eating Inventory (Stunkard and Messick, 1985)
-  R: “I deliberately take small helpings as a means of controlling my weight.”
-  D: “I usually eat too much as social occasions, like parties and picnics.”
-  H: “I am always hungry enough to eat any time.”

##  Current BMI in relation to tertiles of dietary disinhibition and restraint (Hays et al. 2002)

**Body mass index (kg/m****2****)**

**Low**

**Med**

**High**

**Low**

**Med**

**High**

**Restraint tertile**

**Disinhibition**
**tertile**

**31.0**

**28.9**

**28.0**

**25.6**

**25.7**

**25.3**

**23.2**

**23.3**

**23.3**

**20**

**22**

**24**

**26**

**28**

**30**

**32**

**Hays et al. 2001 (Am J Clin Nutr in press)**

**Notes:**
Finish saying that we recognize other factors are important, too, and that these will be investigated in the study also?

## in women between the age intervals 30-39 and 55-60 y

**Weight change (kg)**

**Low**

**Med**

**High**

**Low**

**Med**

**High**

**Restraint**

**Disinhibition**

**17.2**

**15.1**

**10.3**

**9.6**

**8.6**

**8.0**

**5.3**

**4.2**

**4.0**

**2**

**4**

**6**

**8**

**10**

**12**

**14**

**16**

**18**

**20**

**0**

**Weight Change in Relation to Eating Behavior ***

**(Hays et al, 2002)**

## What causes overeating and weight gain?

- Variety
- Palatability
- Restaurant and other non-home foods
- Eating behavior (restraint, disinhibition)
- Portion size, Liquid calories
- Dietary composition (fat/carbohydrate fiber, glycemic index, energy density, protein)

## Portion Size, Liquid Calories

- Portion size: several studies show increased consumption within meal when portion is larger, even when subjects told more is available (adults, overweight adults, children)
- Liquid calories: review by Mattes (1996) indicated 9% higher energy intake at next meal after liquid meal, compared to 64% less after solid meal and 21% less after semi-solid meal.

## Dietary Composition

- Fat/carbohydrate/energy density
- Fiber
- Glycemic index
- Protein

## 0

- 20

- 40

- 60

- VISIT WEEK

- 50

- 70

- 90

- 110

- FASTING WEIGHT

- 70% Low Glycemic
-  Index diet

- 70% Modified
- Pyramid Diet

- RANDOMIZATION

**Phase1**

- Phase 2

- Phase 3

- WEIGHT LOSS WITH CALORIC RESTRICTION
- (ongoing Tufts EMET study of human caloric restriction)

## Dietary and Biobehavioral Factors in Energy Regulation

**        **_**DIETARY PROPERTIES **_
**Macronutrients:  Physical Properties:**
***Fat                      Energy Density***
***Protein                Fiber (& type)***
***Carb (& type)     Food structure ******	******	******     ******	******     (raw vs. cooked etc)***
***                            ******Glycemic Index***

_**DIETARY PATTERNS**_
**Palatability/Taste**
**Variety within food groups**
**Meal/snack patterns**
**Meal size & interval**

_**DIETARY BEHAVIOR**_
**Restraint/disinhibition**
**Eating out**
**Societal norms**
**Social eating**

**ENERGY INTAKE**

**Body Weight**

## Future Directions

- How important is dietary composition vs. variety, eating out, use of very palatable foods, disinhibited eating patterns, etc? 	We still don’t know, and need to if effective 	recommendations 	are to be developed.
- Does dietary composition matter if you want to lose weight? 	A fairly broad range of diets consistent with current 	recommendations for health can  promote successful weight 	loss – but we still need to quantify whether these recommended 	compositions are more effective for weight loss than the dietary 	compositions (eg low fiber) people prefer to eat

## Summary of Outpatient Intervention Studies(Yao & Roberts 2001)

**Intervention studies >1 months duration that recommended dietary change were summarized. Only those studies that provided advice and/or supplements but did not provide food were used**
**There was no effect of study duration on weight loss**
**Mean effects were greatest for studies making recommendations that increased fat and decreased fiber, and least for those that only increased fat**

**Fat**

**Fiber**

**Fat+Fiber**

**0.9 kg**
**(n=7)**

**1.9 kg**
**(n=12)**

**2.9 kg**
**(n=17)**

## Dietary Variety and Body Fatness in the U.S.: Multiple Regression Models(McCrory et al. 1999)

- VEGETABLES

- HIGH ENERGY DENSE GROUP

** ****Vegetable variety was inversely associated, and sweets, snacks, condiments, entrees, and carbohydrates variety was positively associated with body fatness**

** ****The Variety Ratio (ratio of vegetable to sweets, snacks, condiments, entrees, and carbohydrates variety) was significantly associated with body fatness, but % dietary fat was not**

## Association of dietary factors and physical activity with body fatness in urban Chinese adults living in Beijing (Yao et al. 2003)

**Association of dietary factors and physical activity with body fatness in urban Chinese adults living in Beijing ****(Yao et al. 2003)**

## Predictors of within-subject day-to-day variability in energy intake (Yao et al. 2003)

_**Model 1**_
**Variables****	****	****	****      Estimate****	****SE****	****	****   *****P*****	**** ****Constant****	****    ****	****	****	****4.60****	****	****0.54****	****  ****	**** **
**Energy density (KJ/g)****	****	****0.81****	****	****0.09****	****	****< 0.001**
**Meals at restaurant ****	****	****0.47****	****	****0.18****	****	****0.011**
**(times/d)****	****    ****	**
**Gender*****1*****	****men****	****	****	****2.36****	****	****0.37****	****	****< 0.001**
***1 ***Estimate = 0 for women

## What is the Glycemic Index (GI)?

- 0

- 1

- 2

- TIME AFTER MEAL
- (HOURS)

- LOW GI

- HIGH GI

- BLOOD GLUCOSE

**What is the Glycemic Index (GI)?**

- GI is the area under the blood
- glucose curve after a food amount
- containing 50 g carbohydrate is
- consumed.

*Examples                 GI*
- White bread             100
- Breakfast cereals     90-130
- Cookies                    90-100
- Fruit                          40-70
- Legumes                   30-60
- Vegetables               10-60
- Glucose                    138
- Honey                       104
- Sucrose                     92
- Fructose                    32

## In approximately-controlled studies, energy intake after high-GI test meals averaged 29% more than after low GI test meals of the same macronutrient composition (P=0.005 by paired t test)

**Glycemic Index and **
**Subsequent Energy Intake**
**(Roberts, 2000)**

## Ecological Model

_**Skills**_**: cooking, shopping, sports and                                       exercise expertise**
_**Psychological / Social**_**: self-efficacy, lifestyle, social support, stress and time management, environmental food and exercise norms**
_**Cost and Convenience**_
_**Enjoyment:**_** pleasure from exercise, specific foods**

**Exercise Opportunities**

**Exercise duration, intensity**

**Food availability**

**Good choices, types, portions**

**Genes**

**Body **
**Fatness**

**Energy **
**Expenditure**

** ****Geographical location, **
**  ****Society health belief,**
**  ****Food companies/profit,**
**  ****Restaurants,**
**  ****Working hours,**
**  ****Socio-economic status,**
**  ****Family infrastructure,**
**  ****Advertising,**
**  ****Government health programs,**
**  ****Consumer demand,**
**  ****Education Level**

**Energy **
**Intake**

## Dietary Fat and Obesity *

**The prevalence of overweight has risen while percent dietary energy from fat has fallen**

- * BMI data from NHANES, food data from USDA surveys

**Notes:**

Concerning dietary composition,I think it is clear that recommending a small reduction in dietary fat will not solve our obesity problem. It may help, but the fact is that the prevalence of obesity has risen markedly at a time when the percentage of dietary fat has fallen.  Clinical trial data, shows that a modest reduction in dietary fat results in only a 1-2 kg weight loss when food is consumed ad libitum.  So clearly dietary fat is not the whole story, even though it may be part of it.

## Summary of Outpatient Intervention Studies To Reduce Dietary Fat

**Intervention studies >1 months duration that recommended dietary change were summarized. Only those studies that provided advice but did not provide food were used**
**There was no effect of study duration on weight loss**
**Mean loss was small (0.9 kg)**

**Fat Reduction**

**0.9 kg**
**(n=7 studies)**

## Energy Intake From Covertly Fed Low-Fat vs. High-Fat Diets Matched for Energy Density

**The effects of high fat vs. low fat diets on energy intake were assessed when the diets were matched for energy density and palatability**
**In a randomized 9d cross-over design in 7 twin pairs there was no significant effect of dietary fat on energy intake **

**(Saltzman et al, 1997)**

## Effect of Fiber on Energy Intake (studies >2 days with control treatment)

**Effect of Fiber on Energy Intake (studies >2 days with control treatment)**
**(reviewed by Howarth et al. Nutr Rev 2001;59:129)**

**• ****Among 19 studies of fiber **
**  ****and energy intake, 9 were **
**  ****compared to a control **
**  ****treatment and treatments**
**  ****were approximately **
**  ****controlled for other factors **
**  ****influencing EI**
**• ****No difference between **
**  ****soluble and insoluble fibers. **
**  ****Significantly lower EI in **
**  ****high fiber groups overall **
**  ****(P=0.003)**
**• ****Effect tended to be greater **
**  ****in obese vs. non-obese **
**  ****(82% of control vs. 94%)**

## Summary of Fiber Effects on Weight Loss in Ad Libitum Studies (Howarth et al. Nutr Rev 2001;59:129)

**In 12 studies >4 weeks duration, average fiber supplement of 12 g/d for 3.8 months was given**
**Mean weight loss (33 vs. 11 g/day, equivalent to difference of 1.9 kg/study) was greater for high fiber vs control treatments**
**There was no apparent difference between soluble vs. insoluble fibers, and use of whole foods vs. fiber supplements**
**Effects tended to be greater in obese than non-obese ((2.4 kg/study vs. 0.8 kg/study)**

**P=0.003**