## TAB L E OF CONTENTS
2
. B R E A S T M I L K I

N T A KE
.................................................. 2-1 2
. 1 I N T R O D U C T I O N
............................................... 2-1 2
. 2 S T U D I E S O NB R E A S T M I L K I

N T A KE
............................. 2-2 2
. 2
. 1 P a o e ta l

. , 1 9 8 0
............................................ 2-2 2
. 2
. 2 D e w e y an d L ö nn e r d a l , 1 9 8 3
................................. 2-2 2
. 2
. 3
. B utt e e ta l

. , 1 9 8 4
.......................................... 2-3 2
. 2
. 4
. N e v i l l e e ta l

. , 1 9 8 8
......................................... 2-4 2
. 2
. 5
. D e w e y e ta l

. , 1 9 9 1 a , b

...................................... 2-4 2
. 3 S T U D IE S O NLIP ID C O N T EN T A N D F A T IN T A KE F R O M B R E A S T M ILK

.............................................................. 2-5 2
. 4 O T H E R F A C T O R S
.............................................. 2-7 2
. 4
. 1
. P o p u l at i o no f Nur s i n gIn f ant s ................................ 2-7 2. 4. 2. Inta ke Rate s B a se d o n Nutriti on a l Status
. . . . . . . . . . . . . . . . . . . . . . . 2-8 2
. 5 R E C O M M EN D A T I O N S
.......................................... 2-9 2
. 5
. 1 B r e a s tM i l k Int ak e ......................................... 2-9 2.5.2 L ipid Cont ent and L ipid Intake

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-10 2
. 6 R E F E R EN C E S F O R C H A P T E R 2
................................. 2-11

## L I ST OF TAB L ES T a b l e 2

- 1
. D a i l y Int ak e s o f B r e a s tM i l k

......................................... 2-12 Table 2- 3. Br east Milk Intake a mong E x clusively Br east-f ed Infants During the First 4 Months

Ta ble 2- 6. L ipi d Co nte nt o f Huma n M ilk and Es tim ate d L ipi d Inta ke amon gExc lus ive ly B re a stTable 2- 7. Perce ntag e of Mother s Br east-f eedingNewbor n Infants in the Hospital and Infants at 5 or 6 Months Of Ag e in the United States in 1989 and 1995, by Ethnic Ba ckground and T a b l e 2

- 2
. B r e a s tM i l k

...................................................... 2-12
o f

L i f e .............................................................. 2-13 Table 2- 4. Br east Milk Intake During a 24-hour Period

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-14 Table 2- 5. Br east Milk Intake Estimated by the DARL I NG Study

. . . . . . . . . . . . . . . . . . . . 2-15 f e d In f ant s .......................................................... 2-15
S e l e c t e d D e m o gr a p h i c V ar i a b l e s ......................................... 2-16 Table 2- 8. Confidence in Bre ast Milk Intake Rec ommendations

. . . . . . . . . . . . . . . . . . . . . . 2-17 Table 2- 9. Br east Milk Intake Rate s Derive d from Ke y Studies

. . . . . . . . . . . . . . . . . . . . . . 2-18 Table 2- 10. L ipid Intake Rate s Derive d from Ke y Studies

. . . . . . . . . . . . . . . . . . . . . . . . . . . 2-19 Table 2- 11. Summary of Recommende d Br east Milk And L ipid Intake Rate s . . . . . . . . . . . 2-20

## 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 2 . B RE AS T M I L K I NT AK E
2. 1 IN TR OD UC TIO N Br east fe edingis known to impart a wide r ang e of be nefits to nursinginfants, including protection against infection, increases in cognitive development, and avoidance of allergies due to intolerance to cow’s milk. The American Academy of Pediatrics recommends exclusive breast feeding for approximately the first six months and supports the continuation of breast feeding for the first year and beyond if desired by the mother and child (APP, 2005). However, contaminants may find their way into breast milk of lactating mothers. Lipid soluble chemical compounds accumulate in body fat and may be transferred to breast-fed infants in the lipid portion of breast milk. Water soluble chemicals may also partition into the aqueous phase and be excreted via breast milk. Because nursing infants obtain most (if not all) of their dietary intake from breast milk, they are especially vulnerable to exposures to these compounds. Estimating the magnitude of the potential dose to infants from breast milk requires information on the milk intake rate (quantity of breast milk consumed per day) and the duration (months) over which breast-feeding occurs. Information on the fat content of breast milk is also needed for estimating dose from breast milk residue concentrations that have been indexed to lipid content. Severa l studies have g ener ated data on bre ast milk int ake. T y pically , brea st mil k intake has been measured over a 24-hour period by weighing the infant before and after each feeding without changing its clothing (test weighing). The sum of the difference between the measured weights over the 24-hour period is assumed to be equivalent to the amount of breast milk consumed daily. Intakes measured using this procedure are often corrected for evaporative water losses (insensible water losses) between infant weighings (NAS, 1991). Neville et al. (1988) evaluated the validity of the test weight approach among bottle-fed infants by comparing the weights of milk taken from bottles with the differences between the infants' weights before and after feeding. When test weight data were corrected for insensible weight loss, they were not significantly different from bottle weights. Conversions between weight and volume of breast milk consumed are made using the density of human milk (approximately 1.03 g/mL) (NAS, 1991). Recently, techniques for measuring breast milk intake using stable isotopes have been developed. However, few data based on this new technique have been published (NAS, 1991).

2-1

## 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 Studies among nur sing mother s in industrializ ed countries have shown that intakes amon ginf ants ave ra g e a pp ro ximate ly 75 0 to 80 0 g /da y

(7 28 to 7 77 mL /da y

) d ur ingthe fi rs t 4 t o 5 months of life with a ra ng e of 450 to 1,200 g/day (437 to 1,165 mL/day ) (NA S, 1991). Sim ilar intakes have also bee n repor ted for de velopingcountries (NAS, 1991). Infant birth we ight ha s been shown to influence the rate of intake (NAS, 1991). Infants who a re la rg er at birth and/or nurs e mor e fr e qu e ntl y have be e n s ho wn to h ave highe r i nta ke rate s. Key studies on brea st mil k intake ar e summarized in the followingsections. Recommende d intake rates are based on the results of these key studies, as described in the Exposure Fac tors Handbook

. Relevant data on lipid content and fat intake, bre ast-fe eding duration, and the estimated per centa g e of the U.S. population that breast-f eeds a re a lso presente d.
2. 2 S TU DI ES ON BR EA S T M IL K INT AKE 2.2.1 P ao et al., 1980 Pa o e t a l. ( 19 80 ) c on du c te d a stu dy of 22 he a lthy br e a st- fe d in fa nts to e sti mate br e a st milk int ake r ates. Infants we re c ateg orized as completely brea st-fed or partially brea st-fed. Br east fe edingmothers wer e re cruited through L aL eche L eague groups. Except for one black infant, all other inf ants wer e fr om white middle-class fa milies in sout hwester n Ohio. The g oal of the study was to enr oll infants as close to one month of a g e as possible a nd to obtain rec ords nea r one, thre e, six , and nine months of ag e (Pao e t al., 1980). Howe ver, not a ll mother/infant pairs pa rt ic ipate d at e a c h ti me int e rv a l. D ata we re c oll e c te d f or

the se 22 inf ants us ingthe te st we ighin gme tho d. Re c or ds we re c oll e c te d f or

thr e e c on se c uti ve 24 -h our p e ri od s at e a c h te st interval. The weight of brea st mil k was c onverte d to volume by assuming a density of 1.03 g/mL

. Daily intake rates wer e ca lculated f or ea ch infa nt based on the me an of the three 24-hour periods. Mea n daily brea st mil k intake ra tes for the infants surveyed at e ach time inter val ar e prese nted in Table 2- 1. These data (Ta ble 2-1) a re pr esente d as they are in the repor t of Pao (1980). F or complete ly brea st-fed infa nts, the mean intake rate s were 600 mL/day at 1 month of ag e, 833 mL/day at 3 months of ag e, and 682 mL /day at 6 months of ag e. Partially brea st-fed infants had mea n intake rates of 485 mL/day , 467 mL/day , 395 mL/day , and <554 mL /day at 1, 3, 6, and 9 mo nth s o f a g e , r e sp e c tiv e ly

. Pa o e t a l. ( 19 80 ) a lso no te d th at intake rate s f or

bo y s in bo th gro up s w e re sli ghtl y highe r t ha n f or

g ir ls.

2-2

## 1 The a dvantag e of this study is that data for both exclusi vely and par tially brea st-fed 2 infants wer e collec ted for multiple time periods. Also, data for individual infants we re c ollected 3 over 3 c onsecutive da y s which would ac count for some individual variability

. Howeve r, the 4 number of inf ants in the study was re latively small. In addition, this study did not account f or 5 insensible weight loss which may undere stimate the amount of bre ast milk ingested. 6 7 2.2.2 Dewey and L önnerdal, 1983 8 De we y and L önne rd a l ( 19 83 ) m on ito re d th e die tary int ake of 20 br e a st- fe d in fa nts 9 betwee n the ag es of 1 a nd 6 months. Mostof the infa nts in the study wer e exclusively brea st-fed 10 (five w ere g iven some for mula, and seve ral we re g iven small amounts of solid foods after 11 3 mo nth s o f a g e ). Ac c or din gto D e we y and L önne rd a l ( 19 83 ), the mot he rs we re a ll w e ll 12 e du c ate d a nd re c ru ite d thro ugh L ama ze c hil db ir th c la sse s in the Da vis are a of Ca lif or

nia

. B re a st 13 mil k intake vo lum e wa s e sti mate d b a se d o n tw o 2 4- ho ur te st w e ighin g s p e r m onth. B re a st m ilk 14 intake rates for the various ag e groups ar e pre sented in Table 2-2. B rea st mil k intake ave rag ed 1 5 6 7 3 , 7 8 2 , an d 8 9 6 m L/ d ay at1 , 3 , an d 6 m o nth s o f a g e , r e s p e c t i v e l y. 16 The a dvantag e of this study is that it evaluated bre ast-fe d infants for a period of 6 months 17 ba se d o n tw o 2 4- ho ur ob se rv atio ns pe r i nf ant p e r m onth. Ho we ve r, c or re c tio ns fo r i ns e ns ibl e 18 we ight l os s a pp are ntl y we re no t ma de

. A lso , th e numbe r o f i nf ants in t he stu dy wa s r e lativ e ly 19 small and the study participa nts were not repre sentative of the g ener al population. 20 21 2.2.3. Butte etal., 1984 22 Br east milk intake wa s studied in ex clusively brea st-fed infa nts during the first 4 months 23 of life ( Butte e t al., 1984). B rea stfeedingmothers wer e re cruited through the B aylor Milk Bank 24 Prog ram in Texas. For ty -five mother /infant pairs pa rticipated in the study

. Howeve r, data for 25 so me tim e pe ri od s ( i.e ., 1, 2, 3, or 4 mo nth s) we re mis sin gfo r s ome mot he rs a s a re su lt o f i lln e ss 26 or other f actor s. The mothers we re f rom the middle- to upper -socioec onomic stratum and had a 27 mean a g e of 28.0 ± 3.1 year s. A total of 41 mothers we re white, 2 wer e Hispanic , 1 was Asian, 28 and 1 wa s West Indian. Infant growth progresse d satisfac torily over the course of the study

. 29 The amount of milk i ng ested ove r a 24- hour period was dete rmined by weighing the 30 infant bef ore a nd afte r fe eding

. To estimate insensible we ight loss, the cha ng e in weight of a 31 bottle-fed inf ant duringfee ding w as compa red to the c hang e in weight of the bottle. Ba sed on 2-3

## 1 n i n e s u cc es s i v e f ee d i n gs , i n s en s i b l e w ei gh tl o s s i nth i s i n fantwa s es t i m at edt o b e 3
. 2 ± 3
. 1 g. 2 Test weighing oc curr ed over a 24-hour period for most study participa nts, but int ake a mong 3 se ve ra l in fa nts wa s st ud ie d o ve r l on g e r p e ri od s ( 48 to 9 6 h ours ) t o a sse ss i nd ivi du a l va ri atio n in 4 intake. Mea n brea st mil k intake ra ng ed fr om 723 g/da y

(702 mL/day ) at 3 months to 751 g/da y 5 (729 mL/day ) at 1 month, with an over all mean of 733 g/day (712 mL/day ) for the entire study 6 period (T able 2- 3). Intakes we re a lso calculated on the basis of body weight (Table 2- 3). B ased 7 on the re su lts of te st w e ighin g s c on du c te d o ve r 4 8 to 96 ho ur s, the ov e ra ll m e an v ari atio n in 8 individual daily intake wa s estimated to be 7.9 ± 3.6%. 9 The a dvantag e of this study is that data for a lar g er numbe r of e x clusively brea st-fed 10 infants wer e collec ted than we re c ollected by Pao et al. (1980)

. Howeve r, data wer e collec ted 11 over a shorter time pe riod (i.e., 4 months compar ed to 6 months) and day-to-day varia bility was 12 no t c ha ra c te ri zed fo r a ll i nf ants
. 13 14 2.2.4. Neville et al., 1988 15 Neville et a l. (1988) studied bre ast milk int ake a mong 13 inf ants duringthe first year of 16 lif e . T he mot he rs we re a ll mult ipa ro us , n on smo kin g , Ca uc a sia n w ome n o f m idd le - t o 17 upper- socioec onomic status living in Denve r, CO. All women in the study prac ticed exclusive 18 brea st-fee ding f or at lea st 5 months. S olid foods were introduced at mean ag e of 7 months. 19 Da ily mil k intake wa s e sti mate d b y the te st w e ighin gme tho d w ith c or re c tio ns fo r i ns e ns ibl e 20 weight loss. Data wer e collec ted daily from birth to 14 day s, wee kly from we eks 3 through 8, 21 and monthl y until the stu dy pe ri od e nd e d at 1 ye ar a ft e r i nc e pti on . T he e sti mate d b re a st m ilk 22 intakes for this study are listed in Table 2-4. Mea n brea st mil k intakes we re 770 g/day (748 23 mL/day ), 734 g/day (713 mL/day ), 766 g/day (744 mL/day ), and 403 g/day (391 mL/day ) at 1, 3, 2 4 6 , an d 1 2 m o nth s o f a g e , r e s p e c t i v e l y. 25 In compar ison to the previously described studies, Neville et a l. (1988) collec ted data on 26 numerous day s over a relatively long time pe riod (12 months) and they wer e cor rec ted for 27 insensible weight loss. However , the intake r ates pre sented in Table 2-4 ar e estimated ba sed on 28 intake duringonly a 24-hour period. Conseque ntly , these intake rate s are based on shor t-term 29 data that do not ac count for da y -to-day varia bility amongindividual infants. Also, a smaller 30 numbe r o f s ub je c ts w a s in c lud e d th an in the pr e vio us stu die s. 31 2-4

## 1 2.2.5. Dewey etal., 1991a, b 2 The Da vis Area Resear ch on L actation, Infant Nutrition and Gr owth (DARL I NG) study 3 wa s c on du c te d in 19 86 to e va luate g ro wth p atte rn s, nutr ie nt i nta ke , mo rb idi ty , a nd a c tiv ity le ve ls 4 in infants who wer e bre ast-fe d for at least the first 12 months of life (D ewe y et al., 1991a, b)

. 5 Seventy -three infants ag ed 3 months were included in the study . At subsequent time interva ls, the 6 numbe r o f i nf ants inc lud e d in the stu dy at w a s so me wh at lo we r a s a re su lt o f attr iti on . A ll 7 infants in the study wer e hea lthy and of nor mal g estational ag e and w eight at birth, and did not 8 consume solid foods until after the first 4 months of ag e. The mothers wer e highly educated and 9 of “r elatively high soc ioeconomic status.” 10 Br east milk intake wa s estimated by weighing the infants bef ore a nd afte r ea ch fe eding 11 and cor rec ting f or insensible water loss. Test we ighing s were conducte d over a 4-day period 12 ever y

3 months. This decline is associated w ith the intake of solid food. The r esults of the study 13 indicate that br east milk intake dec lines over the f irst 12 months of life. Mean br east milk intake 14 was e stimated to be 812 g/day (788 mL/day ) at 3 months and 448 g/day (435 mL/day ) at 12 15 months (Table 2-5)

. Ba sed on the e stimated intakes at 3 months of ag e, variability betwee n 16 individuals (coef ficient of va riation ([CV] ) = 16.3% ) wa s highe r than the a vera g e day-to-day 17 varia bility ([CV] = 8.9 ± 5.4%) for the inf ants in the study (De wey et al., 1991a)

. 18 Th e a dv anta g e s o f t his stu dy are that da ta

we re c oll e c te d o ve r a re lativ e ly lon g -t ime 1 9 ( 4 d ays ) p e r i o d ate a c ht e s ti nt e r v a l wh i c hw o u l d a c c o untf o r

s o m e d ay- t o - d ay i n f antv ar i a b i l i ty, 20 and cor rec tions for insensible wate r loss were made. 21 22 2. 3 STU DI ES ON LIP ID CO NT EN T A ND F AT IN TA KE F RO MBREA ST M ILK 23 Human mi lk c onta ins ov e r 2 00 c on sti tue nts inc lud inglip ids , v ari ou s p ro te ins , 24 car bohydrate s, vitamins, mi nera ls, and trac e ele ments as well as e nzy mes and hormone s. The 25 lipid content of brea st mil k varie s acc ordingto the leng th of time that an infant nur ses, and 26 inc re a se s f ro m th e be g inn ingto t he e nd of a

sin g le nurs ingse ssi on (NAS, 19 91 ). Th e lip id 27 po rt ion a c c ounts fo r a pp ro ximate ly 4% of human b re a st m ilk (3 9±4. 0 g/L ) ( NA S, 1 99 1)

. T his 28 value is supported by various studies that eva luated lipid content from human br east milk. 29 Se ve ra l st ud ie s a lso e sti mate d th e qu anti ty of lip id c on sume d b y br e a st- fe e din ginf ants
. T he se 30 values a re a ppropriate for pe rfor ming e x posure a ssessments for nursinginfants when the

2-5

## 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 c ontamin ant( s) have re sid ue c on c e ntr atio ns that are ind e xed to t he fat po rt ion of human b re a st milk.
2.3.1 Butte etal., 1984 Butte e t al. (1984) a naly zed the lipid content of brea st mil k samples taken f rom women who par ticipated in a study of bre ast milk int ake a mong e x clusively brea st-fed infa nts. The study wa s c on du c te d w ithov e r 4 0 w ome n d ur inga 4- month p e ri od

. T he me an li pid c onte nt o f b re a st mil k at va ri ou s in fa nts ’ a g e s is pr e se nte d in Ta ble 2- 6. Th e ov e ra ll l ipi d c onte nt f or

the 4- month study period wa s 34.3 ± 6.9 mg/g(3.4%)

. Butte e t al. (1984) a lso calculated lipid intakes from 24-hour br east milk intakes and the lipid content of the human milk samples. L ipid intake was estimated to rang e fr om 23.6 g/da y

(3.8 g/kg- day ) to 28.0 g/day (5.9 g/kg- day ). The number of women inc luded in this study was small, and these women we re se lected primarily from middle to upper soc ioeconomic c lasses. Thus, data on brea st mil k lipid content fr om t his stu dy may no t be e nti re ly repr e se nta tiv e of br e a st m ilk lip id c onte nt a mon gthe U. S. population. Also, these estimates ar e base d on short-term data, and da y -to-day varia bility was not char acte rized.
2.3.1 Maxwell and Burm aster , 1993 Maxwell and Bur master ( 1993) used a hy pothetical population of 5000 infa nts betwee n birth and 1 year of ag e to simulate a distribution of daily lipid int ake f rom brea st mil k. The hy pothetical population re prese nted both bottle-fed a nd brea st-fed infa nts ag ed 1 to 365 day s. A dis tr ibutio n o f d a ily lip id i nta ke wa s d e ve lop e d, ba se d o n d ata in D e we y e t a l. ( 19 91 b) on br e a st mil k intake fo r i nf ants at 3, 6, 9, and 12 months and br e a st m ilk lip id c onte nt, and surv e y data in Ry an et a l. (1991) on the pe rce ntag e of br east-f ed infa nts under the a g e of 12 months (i.e., approximately 22%). A mode l was used to simulate intake a mong 1113 of the 5000 infants that wer e expected to be brea st-fed. The results of the model indicated that lipid intake among nursinginfants under 12 months of ag e ca n be cha rac terized by a norma l distributi on with a mean of 26.8 g/day and a sta ndard de viation of 7.4 g/day (Table 2-7). The model assumes that nursing infants ar e complete ly brea st-fed a nd does not ac count for inf ants who ar e bre ast-fe d longe r than 1 year . Ba sed on data collecte d by Dewe y et al. (1991b) , Maxwell and Bur master ( 1993) estimated the lipid content of br east milk to be 36.7 g/Lat 3 months (35.6 mg/gor 3.6%) , 39.2 2-6

## 1 g/Lat 6 months (38.1 mg/gor 3.8%) , 41.6 g/Lat 9 months (40.4 mg/gor 4.0%) , and 40.2 g/Lat 2 12 months (39.0 mg/gor 3.9%)

. 3 The a dvantag e of this study is that it provides a “snapshot” of daily lipid int ake f rom 4 brea st mil k for br east-f ed infa nts. These re sults are, howe ver, ba sed on a simulation model and 5 there are uncer tainties associate d with the assumptions made. The e stimated mean lipid intake 6 rate repr e se nts the ave ra g e da ily int ake fo r n ur sin ginf ants un de r 1 2 mo nth s o f a g e . T he se data 7 are useful for perf ormingexposure assessments whe n the ag e of the infant ca nnot be spec ified 8 (i.e., 3 months or 6 months). Also, beca use intake r ates a re inde x ed to the lipid portion of the 9 brea st mil k, they may be used in c onjunction with residue conc entrations index ed to fat content. 10 Howeve r, the study did not ge nerate “ne w” data. A re analy sis of previously repor ted data on 11 brea st mil k intake and br east milk lipid i ntake we re pr ovided. 12 13 2.4 OTHE R F ACTORS 14 Other f actor s associate d with brea st mil k intake include: the f reque ncy of bre ast-fe eding 15 sessions per da y , the duration of brea st-fee ding pe r eve nt, the duration of br east-f eedingduring 16 c hil dh oo d, and the ma g nit ud e and natur e of the po pu latio n th at br e a st- fe e ds (i .e ., so c ioe c on omi c 17 fac tors, ethnicity , etc.)

. 18 19 2.4.1. P opul ation of Nursing In fan ts 20 Acc ordingto the National Ac ademy of Scienc es (NA S), the perc entag e of br east-f eeding 21 women has c hang ed dra matically over the year s (NAS, 1991). The Ross P roducts Division of 22 Abbott L aboratories conduc ted a larg e national mail surve y in 1995 to determine patterns of 23 br e a st f e e din gduri ngthe fi rs t 6 m onths of lif e . T he Ros s L a bo rator y

Mo the rs ’s Sur ve y wa s f ir st 24 develope d in 1955 and has be en expanded to include ma ny more infa nts. Bef ore 1991, the 25 survey was c onducted on a quarte rly basis, and appr ox imately 40,000 to 50,000 questionnaires 2 6 w e r e m a i l e d e a c hqu art e r ( Ryan , 1 9 9 7 )

. B e g i nn i n gi n1 9 9 1 , th e s ur v e y w a s c o n d u c t e d m o nth l y; 2 7 3 5 , 0 0 0 we re m ai l edea chm o nth

. Ov er t i m e, th e r es p o n s e r at e h as b ee nco n s i s t en t l y i nth e r an ge 28 of 50 ± 5%. In 1989 and 1995, 196,000 and 720,000 que stionnaires we re ma iled, respe ctively

. 29 Ryan ( 19 97 ) r e po rt e d r ate s o f b re a st- fe e din gthr ou gh 1 99 5 a nd c omp are d th e m w iththo se in 30 1989.

2-7

## 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 The surve y demonstrates r ece nt increa ses in both the initiation of breast-f eedingand c ontin ue d b re a st- fe e din gat 6 m onths of a g e . T a ble 2- 7 p re se nts the pe rc e nt o f b re a st- fe e din gin hospitals and at 6 months of ag e by selec ted demographic char acte ristics. In 1995, the incidenc e of bre ast-fe edingat birth and at 6 months for all infants was a pproxi mately 60% and 22 % , respe ctively

. The larg est incre ases in the initiation of brea st-fee ding be tween 1989 a nd 1995 occur red a mong w omen who (1) wer e B lack, we re le ss than 25 year s of ag e, ea rned le ss than $1 0, 00 0 p e r ye ar, ha d n o mo re tha n gra de sc ho ol e du c atio n, and we re liv ingin t he South Atla nti c reg ion of the U.S.; (2) ha d infants of low birth we ight; (3) wer e employed full time outside the home at the time they rec eived the sur vey ; and (4) pa rticipated in the Women, Infants, and Children program (WI C). In 1995, as in 1989, the initiation of brea st-fee ding w as highest among women who we re greater than 35 year s of ag e, ea rned more than $25,000 per year , and we re colleg e educ ated; women who did not participate in the WI C program; and w omen who we re liv ingin t he Mo unta in a nd Pa c if ic re g ion s o f t he U. S. Data on the actua l leng th of time that infants continue to bre ast-fe ed beyond 5 or 6 months are limited (NAS, 1991). How ever , Maxwell and Bur master ( 1993) estimated that approximately 22 perc ent of infa nts under 1 year of ag e ar e bre ast-fe d. This estimate is based on a re analy sis of survey data in Ryan et a l. (1991) collec ted by Ross L aboratories (Maxwell and Bur master, 1993)

. 2. 4. 2. Int akeRa te s Ba se d on N ut r it ion al S ta tu s Inf or

matio n o n d if fe re nc e s in the qu a lity and qu anti ty of br e a st m ilk on the ba sis of e thn ic or socioec onomic char acte ristics of the population is limi ted. L önnerda l et al. (1976) studied brea st mil k volume and composition (nitrog en, lac tose, proteins) among unde rprivileg ed and privileg ed Ethiopian mothers. No significant diff ere nces w ere observe d betwee n the data f or these two groups. Simil ar data wer e obser ved for well-nourishe d Swedish mothers. L önnerda l et al. (1976) stated that these r esults indicate that bre ast milk quality and quantity are not affe cted by mate rn a l ma lnutr iti on . H ow e ve r, B ro wn e t a l. ( 19 86 a , b ) n ote d th at th e la c tatio na l c a pa c ity and e ne rgy c on c e ntr atio n o f m arg ina lly-n ouri sh e d w ome n in B ang la de shwe re “ mod e stl y le ss than in better nourished mothers.” B rea st mil k intake rates for infa nts of marg inally -nourished women in this study wer e 690 ± 122 g/day at 3 months, 722 ± 105 g/day at 6 months, and 719 ± 11 9 g/da y

at 9 m onths of a g e (B ro wn e t a l., 19 86 a ). B ro wn e t a l. ( 19 86 a ) o bs e rv e d th at br e a st 2-8

## 1 mil k f ro m w ome n w ithlarg e r m e a sure me nts of arm c ir c umf e re nc e and tr ic e ps sk inf old thi c kn e ss 2 had higher c oncentr ations of fat and ene rgy than mothers with less body fat. Positive corre lations 3 be tw e e n mate rn a l w e ight a nd mil k f at c on c e ntr atio ns we re a lso ob se rv e d. Th e se re su lts su g g e st 4 that mi lk c omp os iti on may be a ff e c te d b y mate rn a l nutr iti on a l st atus
. 5 6 2.5 RECOMMENDA TIONS 7 The studies desc ribed in this section wer e used in sele ctingrec ommended value s for 8 brea st mil k intake, fat content and f at intake, a nd other re lated fa ctors. Although differ ent survey 9 designs, testing pe riods, and populations wer e utiliz ed by the studies to estimate intake, the me an 10 and standa rd deviation estimates reporte d in these studies are relatively consistent. There are , 11 howeve r, limitations wit h the data. With the exception of Butte ( 1984), data wer e not pre sented 12 on a body weight basis. This is particularly important since intake r ates may be higher on a body 13 weight basis for young er infa nts. Also, the data used to de rive the r ecommendations are ove r 15 14 year s old and the sample size of the studies wa s small. Other subpopulations of conc ern suc h as 15 mothers hig hly committed to breast fe eding — sometimes for periods longe r than 1 year — may 16 not be ca ptured by the studies prese nted in this chapter. F urther r esea rch is nee ded to identify 17 these subgroups and to g et better estimates of bre ast milk int ake r ates. Ta ble 2-8 pre sents the 18 c on fi de nc e ratin gfo r b re a st m ilk int ake re c omm e nd atio ns . 19 20 2. 5. 1 Br e as t M ilk I nt ake 21 The bre ast milk int ake r ates for nursinginfants that have been r eporte d in the studies 22 de sc ri be d in thi s se c tio n a re summa ri zed in T a ble 2- 9. It sh ou ld b e no te d th at th e de c re a se in 23 brea st mil k intake with ag e is likely a re sult of complementar y

foods beingintroduced a s the 24 child grows and not ne cessa rily a dec rea se in total energy intake. In order to conform to the ne w 25 standardized ag e grouping s used in this Handbook (see Chapter 1) , data f rom Pao et a. ( 1980), 26 Dewe y and L önnerda l (1983), B utte et al. (1984) , Neville et a l. (1988), De wey et al. (1991a), and 27 Dewe y et al. (1991b) wer e compiled f or ea ch month of the fir st y ear of life. F or some months 28 multipl e studies wer e ava ilable; for other s only one study was available. Weighted means w ere 2 9 ca l cu l at edfo r e ac hage i nm o nth s . Up p er p er ce nt i l es we re ca l cu l at edas th e m i d p o i nto f th e r an ge 30 of up pe r p e rc e nti le s o f t he stu die s ava ila ble fo r e a c h a g e in m onths . T he se month- by-m onth 31 intakes we re c omposited to yield intakes for the standar dized ag e groups by takingan 2-9

## 1 2 3 4 5 6 7 8 9 10 11 unwe ighte d ave ra g e , a ssumin gthat in the g e ne ra l po pu latio n, e a c h a g e (e .g ., 3, 4, and 5 mo nth s) is equally repr esente d.
2. 5. 2 Lipi d Co nt e ntand L ipid I nt ake Recommende d lipid int ake r ates a re pr esente d in Table 2-10. T he table pa rallels the brea st mil k intake table ( Table 2- 9). F igur es we re c alculate d assuming a lipid content of 4% (B utte et al.,1984; NAS, 1991; Maxwell and Bur master, 1993)

. An exception to this m ethod was employed in the ca se of the B utte et al. (1984) study , wher e lipid intakes wer e provide d in the stu dy . T he va lue s f ro m th e stu dy we re us e d in pla c e of the e sti mate d li pid int ake s.

2-10

## 5

10

15

20

25

30

35

40

45

50

1 2. 6 REF ERENC ES F OR CH APT ER 2 2 3 4 AP P ( 2005) B r ea s t f ee di n g a n d t h e u s e of h u man mi l k

. Pol i cy St at eme n t
. Pedi at r i cs V ol

. 115 N o. 2 Fe br u ar y 2005, p p . 4 9 6 -5 0 6 a v a ilab le o n li n e a t h t t p: / / a a pp o l i c y . a a pp u b l i c a t i o n s . o r g/ c gi / c o n t e n t / f u l l / pe di a t r i c s ; 115 / 2/ 496 

## 6 7 8 B r own, K
. H
. ; Akht ar , N
. A
. ; Ro bert s on, A. D
. ; Ahmed , M
. G
. ( 19 86 a) Lac t at i onal ca paci t y of mar gi nal l y nour i s hed m o the rs : re la tio n sh ip s b e tw e e n m a te rn a l nu triti o n a l statu s a n d q u a n tit y a n d p ro x im a te c o m p o sitio n o f m ilk. Pedi at r i cs . 78: 909- 919. 

## 9 11 12 B ro w n, K .H .; R o b ertso n, A .D .; A kh t ar, N .A
. (1 9 8 6 b ) La ctati o na l ca p ac i t y of m arg i na l l y no urished m o t he rs: i nfants' mi l k n u t r i en t c on s u mpt i on a n d pa t t er n s of g r owt h

. Pedi at r i cs . 78: 920- 927. 

## 13 14 B ut t e, N
. F. ; G ar za, C. ; Smi t h, E
. O
. ; N i chol s , B
. L. ( 19 84 ) H uman mi l k i nt ake an d gr owt h i n e xcl us i vel y bre as t
- f ed i n f an t s . J ou r n al of Pedi at r i cs . 104: 187- 195. 

## 16 17 18 D e w e y, K .G .; L ö n n e rd a l, B
. (1 9 8 3 ) M ilk a n d nu trie n t i n ta k e o f b re a st-f e d infa n ts fro m 1 to 6 m o n ths :re la tio n to g r owt h a n d f at n es s . J ou r n al of Pedi at r i c G as t r oen t er ol og y a n d N u t r i t i on . 2: 497- 506. 

## 19 D ew ey, K .G .; H einig, J.; N o m m sen , L .A .; L ö nn erd al, B
. (1 9 9 1 a) M atern al versu s i nfant f ac t o rs related t o b rea st 

## 21 mi l k i n t ak e an d r es i du al v ol u me: t h e D ARLI N G s t u dy

. Pedi at r i cs . 87: 829- 837. 

## 22 23 24 D e w e y, K .G .; H e inig , J.; N o m m se n , L .; L ö n n e rd a l, B
. (1 9 9 1 b ) A d e q u a c y o f en e rg y inta k e a m o n g b re a st-f e d infa n ts i n t h e D ARLI N G s t u dy : r el at i on s h i ps t o g r owt h , v el oci t y , mor bi di t y , a n d a ct i v i t y l ev el s . T h e Jou r n al of Pedi at r i cs . 119: 538- 547. 

## 26 27 28 Lö nnerda l , B
. ; Fo rs um , E
. ; G eb re- M ed hi m , M
. ; H o m b raes, L. (19 7 6 ) B reast m i l k co m p o si t i o n i n E t hi o p i an and Sw edi s h mot h er s : l ac t os e, n i t r og en , a n d pr ot ei n c on t en t s . T h e Amer i ca n J ou r n al of Cl i n i ca l N u t r i t i on . 29: 1134­ 1141. 

## 29 31 32 M ax w ell , N .I. ; B urm aster, D .E
. (1 9 9 3 ) A si m ulati o n m o d el t o esti m ate a d i st ribu t i o n o f l i p i d i ntak e fro m b rea st mi l k du r i n g t h e f i r s t y ea r of l i f e. J ou r n al of Expos u r e Ana l y s i s a n d Env i r on men t al Epi demi ol og y . 3: 383- 406. 

## 33 34 N a t i on a l Ac a de my of S c i e n c e s ( N AS )

. ( 19 91 ) Nu t r i t i on du r i n g l a c t a t i on . W a s h i n g t on , DC. Na t i on a l Ac a de my P ress. 

## 36 37 38 N evi l l e, M
. C
. ; K el l er , R. ; Seac at , J. ; Lut es , V
. ; N ei f er t , M
. ; et al

. ( 19 88 ) St udi es i n h uman l act at i on: mi l k v ol umes in la c ta ting w o m e n d u rin g the o n se t o f l a c ta tio n a n d full l a c ta tio n . A m e ric a n J o u rn a l o f C linic a l N u triti o n . 48: 1375- 1386. 

## 39 41 P ao , E
. M
. ; H i nes, J. M
. ; R o che, A
. F. (19 8 0 ) M i l k i nt akes and f eed i ng pa t t erns of b reast
- f ed i nf ant s. Journal o f t he Amer i ca n D i et et i c As s oci at i on . 77: 540- 545. 

## 42 43 44 R y an, A. S. ; Rus h, D
. ; K r i ege r , F. W
. ; Lewan do ws ki , G
. E
. ( 19 91 ) Recent decl i nes i n br eas t f eedi ng i n t he U ni t ed St at es , 1984- 1989. Pedi at r i cs . 88: 719- 727. 

## 46 47 48 R ya n , A .S
. (1 9 9 7 ) T h e re su rg e n c e o f b re a stfee d ing in the U n ited S ta te s. P e d ia tric s. 9 9 (4 ):e 1 2
. h t t p: / / ww w. pedi at r i cs . or g / cqi / con t en t / f u l l / 99/ 4/ e12. 

## 49 51 52

2-11T a b le 2 -1
. D a ily In ta k e s o f B re a st M ilk

Age Nu mb ero f I n fa n ts I nt a ke
Mea n ±SD (mL/ d a y) a In ta ke Ra n ge (mL/ d a y) Com pletely Brea st-f ed 1 m onth 3 m onths 6 m onths 11 2 1 600 ±159 833 682 426 - 989 645 - 1,000 616 - 786 P artially Brea st-f ed 1 m onth 3 m onths 6 m onths 9 m onths 4 11 6 3 485 ± 79 467 ±100 395 ±175

<554 398 - 655 242 - 698 147 - 684 451 - 732

a Da ta

e xpre ss ed as m ea n ±s ta ndar d de v iation. Sourc e: Pao e t a l., 1980.

T ab l e 2

- 2
. B reast M i l k Int akes f o r i nf ant s aged 1 t o 6 m o nt hs

Age (m on ths ) Nu mb ero f I n fa n ts I nt a ke
Mea n ±SD (mL/ d a y) In ta ke Ra n ge (mL/ d a y) 1 16 673 ±192 341-1003 2 19 756 ±170 449-1055 3 16 782 ±172 492-1053 4 13 810 ±142 593-1045 5 11 805 ±117 554-1045 6 11 896 ±122 675-1096 Sourc e: D ew ey and L önner dal , 1983



## 2-12T a b le 2 -3
. B re a st M ilk In ta k e a m o n g E x c lus ive ly B re a st-f e d In fan ts D u rin g t h e F irst 4 M o n ths o f L ife Age (m o n th s) Nu mb ero f I n fa n ts Intake (g /day ) Intake (g /kg- day) B ody Wei g ht a (kg) Mea n ±SD Mea n ±SD 1 37 751.0 ±130.0 159.0 ±24.0 4.7 2 40 725.0 ±131.0 129.0 ±19.0 5.6 3 37 723.0 ±114.0 117.0 ±20.0 6.2 4 41 740.0 ±128.0 111.0 ±17.0 6.7

a Ca lc ulate d by div idingbre as t milk int ake (g/da y) by bre as t milk int ake (g/kg -da y). Sourc e: B utte e t a l., 1984



## 2-13T abl e 2- 4. B r ea s t M i l k I n t ak e D u r i n g a 24- h ou r Per i od Age (d a ys) Nu mb ero f I n fa n ts In take ( g/day) In take b y age ca tegory (g /d) b Mea n ±SD Ra n ge 1 2 3 4 5 6 7 8 9 10 11 14 21 28 6 9 10 10 11 9 7 8 9 9 8 9 10 13 44 ±71 182 ±86 371 ±153 451 ±176 498 ±129 508 ±167 573 ±167 581 ±159 580 ±76 589 ±132 615 ±168 653 ±154 651 ±84 770 ±179 -31- 149 a 44-355 209-688 164-694 323-736 315-861 406-842 410-923 470-720 366-866 398-934 416-922 554-786 495-1144 526 ±227

35 42 49 56 12 12 10 12 668 ±117 711 ±111 709 ±115 694 ±98 465-930 554-896 559-922 556-859 699 ±108

90 10 734 ±114 613-942 734 ±114 120 12 711 ±100 570-847 711 ±100 150 12 838 ±134 688-1173 838 ±134 180 13 766 ±121 508-936 766 ±121 210 12 721 ±154 486-963 721 ±154 240 9 622 ±210 288-1002 622 ±210 270 12 618 ±220 223-871 618 ±220 300 11 551 ±234 129-894 551 ±234 330 8 554 ±240 120-860 554 ±240 360 8 403 ±250 65-770 403 ±250

aNe g at iv e v alue due to i nse nsi ble w ei g ht l oss c orr ec tion. b Mul tipl e data s ets w ere c om bin ed by prod ucin g s im ulated d ata s ets f ittin g the k no wn m ean and SD f or each ag e, com posi tingthe data s et s to c orr es pond to ag e g roups of 0 t o < 1 m onth a nd 1 t o < 2 m onths , a nd c al cul at ingne w m ea ns and SD’s on th e c om po sited data. SD =s ta ndar d de v iation. Sourc e: Ne v ill e et a l., 1988



## 2-14T abl e 2- 5. B r ea s t M i l k I n t ak e Es t i mat ed by t h e D ARLI N G St u dy
Age (m on ths ) Nu mb ero f I n fa n ts In ta ke (g/d a y) Mea n ± SD 3 73 812 ±133 6 60 769 ±171 9 50 646 ±217 12 42 448 ±251 Sourc e: De w ey e t a l., 1991b

T a b le 2 -6
. L ip id C o n te n t o f H u m a n M ilk a n d E stim a te d L ip id In ta k e a m o n g E x c lus ive ly B re a st-f e d In fan ts
Age (m on ths ) Nu mbe r of Observat ions Li pid Conte nt (m g/g) Li p id C o n t e n t% a Li p id I nt a ke (g/d a y) Mea n ±SD Li p id I nt a ke (g/k g-d a y) Mea n ±SD Mea n ±SD 1 2 3 4 37 40 37 41 36.2 ±7.5 34.4 ±6.8 32.2 ±7.8 34.8 ±10.8 3.6 3.4 3.2 3.5 28.0 ±8.5 25.2 ±7.1 23.6 ±7.2 25.6 ±8.6 5.9 ±1.7 4.4 ±1.2 3.8 ±1.2 3.8 ±1.3

a P erc en ts calc u la te dfrom li p idco n te n t r ep o rt edin mg/g. Sourc e: B utte , e t a l., 1984



## 2-15Ta b l e 2

- 7
. P e r c e n t a g e o f M o t h e r s Br e a s t
- f e e d i n g Ne w b o r n I n f a n t s i n t h e Ho s p i t a l a n d I n f a n t s a t 5 o r 6 M o n t h s Of A ge i n t he U ni t ed St at es i n 1989 an d 19 95 , by E t hn i c B ack gr ound an d Sel ect ed D emo gr aphi c V ar i abl es Perc ent ag e of Mothe rs Br ea st -Fe edi ng Cha ra ct eris tic In H ospi ta l At 6 Months

a a 1 9 8 9 1 9 9 5 Ch an ge 1 9 8 9 1 9 9 5 Ch an ge A ll Inf ant s 52.2 59.7 14.4 18.1 21.6 19.3 White 58.5 64.3 9.9 21.0 24.1 14.8 Black 23.0 37.0 60.9 6.4 11.2 75.0 Hi spa nic 48.4 61.0 26.0 13.9 19.6 41.0 Maternal A ge (y ears) <20 30.2 42.8 41.7 5.6 9.1 62.5 20-24 4.2 52.6 16.4 11.5 14.6 27.0 25-29 58.8 63.1 7.3 21.1 22.9 8.5 30-34 65.5 68.1 4.0 29.3 29.0 (1.0) b 35+ 66.5 70.0 5.3 34.0 33.8 (0.6) b To t al F ami l y In co me <$10, 000 31.8 41.8 31.4 8.2 11.4 39.0 $10,000 - $14,999 47.1 51.7 9.8 13.9 15.4 10.8 $15,000 - $24,999 54.7 58.8 7.5 18.9 19.8 4.8 $ 25,000 66.3 70.7 6.6 25.5 28.5 11.8 Mate rna l E duca tion Gra de Sc hool 31.7 43.8 38.2 11.5 17.1 48.7 Hi g h Sc hool 42.5 49.7 16.9 12.4 15.0 21.0 Co ll ege 70.7 74.4 5.2 28.8 31.2 8.3 Mate rna l E m ploy m ent E mp l o yedF u l l Ti me 50.8 60.7 19.5 8.9 14.3 60.7 E mp l o yedP artTi me 59.4 63.5 6.9 21.1 23.4 10.9 Not Em plo y ed 51.0 58.0 13.7 21.6 25.0 15.7 Bi rth W ei g ht Lo w ( # 2 ,5 0 0 g) 36.2 47.7 31.8 9.8 12.6 28.6 Norm al 53.5 60.5 13.1 18.8 22.3 18.6 Parit y Prim ipa rous 52.6 61.6 17.1 15.1 19.5 29.1 Mult ipa rous 51.7 57.8 11.8 21.1 23.6 11.8 W IC Part ic ipation c Parti ci pant 34.2 46.6 36.3 8.4 12.7 51.2 Nonpa rti ci pant 62.9 71.0 12.9 23.8 29.2 22.7 U. S. C ens us Re g ion Ne w Eng la nd 52.2 61.2 17.2 18.6 22.2 19.4 Middl e Atla ntic 47.4 53.8 13.5 16.8 19.6 16.7 East North Central 47.6 54.6 14.7 16.7 18.9 13.2 We st North Centr al 55.9 61.9 10.7 18.4 21.4 16.3 South A tla

ntic 43.8 54.8 25.1 13.7 18.6 35.8 East Sou th Central 37.9 44.1 16.4 11.5 13.0 13.0 We st Sou th Central 46.0 54.4 18.3 13.6 17.0 25.0 Mounta in 70.2 75.1 7.0 28.3 30.3 7.1 Paci f ic 70.3 75.1 6.8 26.6 30.9 16.2

a T he per ce nt c hang e w as c al cul at ed usi ngthe f ollowingf orm ula : % bre as tf ed in 1984 - % bre as tf ed in 1989 / % bre as tf ed in 1984. b Figure s in pa re nthe se s indic at e a dec re as e in t he rate of bre as tf ee dingf rom 1989 t o 1995. WI C i n d i ca t es Wo men , In fan t s, an dCh i l dr en sup p l eme n t al fo o dp r o gr am. Sourc e: Ryan, 1997 

## 2-16 cT ab l e 2

- 8
. C o nf i d ence i n B reast M i l k Int ake R eco m m end at i o ns
Cons ide rations Rationa le Rating 

### S tu d y E le me n ts Level o f peerrevi ew All key stu d ie s are from pe er r evi ewed l it era tu re. Hi gh Accessi b il it y P ap ers are wid el y avail ab le from pe er r evi ewed j o u rn al s. Hi gh Rep ro du ci b il it y Me th o d o lo gy us edw as cl ear ly pr esen te d

. Hi gh Fo cu s o nfacto r o f in te res t The focu s o f th e stu d ie s was on est imati n g br eastmil k in ta ke. Hi gh Dat a p ert in en t t o U. S. Su b p o p u la ti o n s o f th e U. S. w ere th e focu s o f all t h e key stu d ie s. Hi gh P ri m ary dat a All th e stu d ie s were b ased on pr imary dat a. Hi gh C urr en cy S tu d i es wer e c o n du ct ed b et wee n1 9 8 0

- 1 9 9 7
. M ed i u mHi gh A dequa cy of

data c olle ct ion period Infants w ere not stud ied lon g e no ugh to f ully characteriz e day to day v aria bili ty
. W ith the e x ception of N ev ill e et a l. (1988) , the m ea sur ement s w er e m adein f re quenc y (e .g ., onc e a m onth) and the dat a m ay not re pre se nt t he pote ntia l f irs t y ea r of la ct at ion (both f or le ss tha n 1 m onth of a g e and f or l ong itudi nalm ea sur ement s of m ore tha n 6 m onths ). Me dium

V alidity of a pp roach Metho do logy uses c hanges in bo dy w eight as a surrogate f or to tal ingestion

. T his is the best m etho do logy there is to estim ate breas t m ilk ing es tion; how ev er , be ca use the re are li mita tions to this appr oac h, t he conf ide ncera tingw as judg ed to be low

. M othe rs w er e ins truc te d in the us e of inf ant s ca le s to minimiz e m ea sur ement e rr ors . T hre e out of the 5 s tudie s cor re ct ed dat a f or i nse nsi ble w at er los s. L ow

Study s iz e T he sa m

ple s iz es us ed in t he k ey s tudie s w er e f ai rly s m al l ( ra ng e 13­ 73). L ow
Repre se ntativ ene ss of the popula tion Populati on are repre se ntativ e of the g ene ra l mothe r- inf ant pa ir population. Hi gh
Cha ra ct eriz at ion of v aria bili ty Not v er y

w el l c har ac te riz ed. I nf ant s under 1 month not c apt ure d, m othe rs c om m itt ed to br ea st f

ee dingov er 1 y ea r not c apt ure d. L ow
Lack of b ia s in stu dy de si gn (high ratin g is desirable) Bias in the stud ies w as not characterize d. Tw o ou t of 5 studies corrected f or in sensible w ater loss. L ow
Me as ure m ent e rr or A ll m othe rs w er e w el l e duca te d and tr ai ned in t he use of the s ca le w

hic h he lpe d minimiz e m ea sur ement e rr or. N ot c orr ec tingf or ins ens ible w at er los s m ay unde re st im at e inta k e. Mot her s se le ct ed f or the s tudie s w er e v olunte er s; the re f ore re spons e rate doe s not a pply

. P op ulatio n stud ied m ay intro du ce som e bias in the results (see abov e)

. Me dium



### Oth erE le me n ts Num ber of

s tudie s T her e ar e 5 k ey s tudie s. Me dium Agreementbe tween rese arc h ers The re i s go o dagree m en t amon g rese arc h ers . Hi gh 

### Overall R ating Stu dies w ere w ell designed. Results w ere c on sistent. Sam ple size w as f ai rly low

. Va ria

bili ty c annot be c har ac te riz ed due to l imita tions in data c olle ct ion pe riod. M edium



## 2-17T abl e 2- 9. B r eas t M i l k I nt ake Rat es D er i ved f r om K ey St udi es

A ge (m ont hs ) Nu m ber of Ch ildren Me an I n t a ke ( m L/ d ay) Up per Pe rc en t il e Cons um pt ion Reference W e i g h t e d M e a n I n t a ke an d U p p erPe rc en t il e C on s u m p t ion b (across all Key St ud ies) ( m L/ d ay) ( m L/ d ay) a ind ivid ual age com posit e ages Mean Up per Mean d Up per 0 128 511 952 N e v il l e e t a l ., 198 8 511 952 511 952

1 11 37 13 16 600 729 679 673 918 982 888 1057 P ao e t a l ., 198 0 Buttee t a l ., 198 4 N e v il l e e t a l ., 198 8 D e w e y an d L ö nne r dal , 1 983 687 973 703 992 2 1 0 713 934 N e v il l e e t a l ., 198 8 720 1015 19 756 1096 D e w e y an d L ö nne r dal , 1 983 40 704 958 Buttee t a l ., 198 4 2 833

— c P ao e t a l ., 198 0 37 702 923 Buttee t a l ., 198 4 757 1005 3 12 690 884 N e v il l e e t a l ., 198 8 16 73 782 788 1126 1047 D e w e y an d L ö nne r dal , 1 983 D e w e y e t a l ., 199 1b 761 1005 4 1 2 814 1074 N e v il l e e t a l ., 198 8 754 1031 13 810 1094 D e w e y an d L ö nne r dal , 1 983 41 718 967 Buttee t a l ., 198 4 5 1 3 744 979 N e v il l e e t a l ., 198 8 772 1009 11 805 1039 D e w e y an d L ö nne r dal , 1 983 1 682

— c P ao e t a l ., 198 0 12 700 999 N e v il l e e t a l ., 198 8 759 1070 6 11 60 896 747 1140 1079 D e w e y an d L ö nne r dal , 1 983 D e w e y e t a l ., 199 1b

584 1009 7 9 604 1012 N e v il l e e t a l ., 198 8 604 1012 8 12 600 1027 N e v il l e e t a l ., 198 8 600 1027 9 1 1 535 989 N e v il l e e t a l ., 198 8 610 1019 50 627 1049 D e w e y e t a l ., 199 1b 10 8 538 1004 N e v il l e e t a l ., 198 8 538 1004 11 8 391 877 N e v il l e e t a l ., 198 8 391 877 12 42 435 922 D e w e y e t a l ., 199 1a; 199 1b 435 922 435 922

a Uppe r pe r ce nti l e is r e po rte d ( me an plus 2 s tandar d de v iati o ns ) , e x cept as no te d. b M i d d le of t h e ra n ge. Standard de viatio ns and upp e r pe rce ntile s no t cal culate d fo r s mal lsampl e siz e s. d Cal culate d as an unw e ighte d me an, assumingthat in the g e ner alpopul ation, e ach ag e ( e .g ., 3, 4, an d 5 m o nth s ) is e qua l l y r e pr e s e nte d.



## 2-18 cT abl e 2- 10
. Li pi d In t ake Rat es D er i ved f r om K ey St udi es

A ge (m ont hs ) Nu m ber of Ch ildren Me an I n t a ke ( m L/ d ay) U p p erPe rc en t il e Cons um pt ion

( m L/ d ay) a Reference W e i g h t e d M e a n I n t a ke an d U p p erPe rc en t il e C on s u m p t ion b (across all Key St ud ies) ( m L/ d ay) ind ivid ual age com posit e ages Mean Up per Mean d Up per
0 128 20. 4 38. 1 N e v il l e e t a l ., 198 8 20 38 20 38

1 11 37 13 16 24.0 27.2 27.2 26.9 36.7 43.7 35.5 42.3 P ao e t a l ., 198 0 Buttee t a l ., 198 4 N e v il l e e t a l ., 198 8 D e w e y an d L ö nne r dal , 1 983 27 40
27 40 2 1 0 28.5 37.4 N e v il l e e t a l ., 198 8 27 41 19 30.2 43.8 D e w e y an d L ö nne r dal , 1 983 40 24.5 38.3 Buttee t a l ., 198 4 2 33.3

— c P ao e t a l ., 198 0 29 40 37 22.9 36.9 Buttee t a l ., 198 4 3 12 27.6 35.4 N e v il l e e t a l ., 198 8 16 73 31.3 31.5 45.0 41.9 D e w e y an d L ö nne r dal , 1 983 D e w e y e t a l ., 199 1b 29 40 4 1 2 32.6 43.0 N e v il l e e t a l ., 198 8 28 43 13 32.4 43.8 D e w e y an d L ö nne r dal , 1 983 41 24.9 41.6 Buttee t a l ., 198 4 5 1 3 29.8 39.2 N e v il l e e t a l ., 198 8 31 40 11 32.2 41.6 D e w e y an d L ö nne r dal , 1 983 1 27.3

— c P ao e t a l ., 198 0 30 43 12 28.0 40.0 N e v il l e e t a l ., 198 8 6 11 60 35.8 29.9 45.6 43.2 D e w e y an d L ö nne r dal , 1 983 D e w e y e t a l ., 199 1b

23 40 7 9 24. 2 40. 5 N e v il l e e t a l ., 198 8 24 40 8 12 24. 0 41. 1 N e v il l e e t a l ., 198 8 24 41 9 1 1 21.4 39.6 N e v il l e e t a l ., 198 8 24 41 50 25.1 42.0 D e w e y e t a l ., 199 1b 10 8 21. 5 40. 2 N e v il l e e t a l ., 198 8 22 40 11 8 15. 6 35. 1 N e v il l e e t a l ., 198 8 16 35 12 42 17. 4 36. 9 D e w e y e t a l ., 199 1a; 199 1b 17 37 17 37

a Uppe r pe r ce nti l e is r e po rte d ( me an plus 2 s tandar d de v iati o ns ) , e x cept as no te d. b M i d d le of t h e ra n ge. Standard de viatio ns and upp e r pe rce ntile s no t cal culate d fo r s mal lsampl e siz e s. d Ca lculat ed as a n u nweightedmean , as su min g th atin th e g eneral popu lati on, each age ( e .g ., 3, 4, an d 5 m o nth s ) is e qua l l y r e pr e s e nte d.
e C a lc u la t edfrom b rea st mi lki n t a k e as su mi n g ali p i dc on t en tof 4 % (NAS, 1 9 9 1 ; B u t t e et al., 1 98 4, an d M axwe llan d B urm ast er, 19 93 ). EXC EPT da ta from Bu tt e e t a l. (19 84 ), whe r e l ipi d dataw e r e pr o v ide d.



## 2-19 cT abl e 2- 11
. Summary of Recom mended B r eas t M i l k And Li pi d In t ake Rat es

A ge B r eas t M i l k I nt ake , mL/ day Li pi d In t ake , mL/ day a M e a n U p p e r P e rc e n til e M e a n U p p e r P e rc e n til e bi r t h t o < 1 mon t h 511 952 20 30

1 t o < 3 mon t h s 703 992 27 40 3 t o < 6 mon t h s 761 1005 29 40 6 t o < 12 mon t h s 584 1009 23 40

bi r t h t o 1 y ea r 642 973 25 39

a T h e r ec ommen ded v al u e f or t h e l i pi d c on t en t of br ea s t mi l k i s 4. 0 pe r ce n t
. Se e Se ct i on 2. 5. 2. b M i d d l e o f t he ran ge o f up p er p erc en t i l e v alue s.



## 2-20