## TABLE O F CONTENTS
1 1
. B O D YWE I G H TS T U D I E S
............................................... 11 -1 1 1
. 1 IN T RO D U C T I ON
.............................................. 11 -1 1 1
. 2 B O D YWE I G H TS T U D I E S
...................................... 11 -1 1 1
. 2
. 1 H am i l le ta l
. , 1 9 7 9
........................................ 11 -1 11.2.2. NationalCenterfor Health Stati stics, 1987
. . . . . . . . . . . . . . . . . . . . . 11 -1 1 1
. 2
. 3 . B urm a s t e r an d C r o u c h , 1 9 9 7
................................ 11 -2 11.2.4 U.S. EPA, 2000
.......................................... 11 -3 1 1
. 2
. 5 O g d e ne ta l
. , 2 0 0 4
........................................ 11 -3 11 .2 .6 EP A Ana lys is o f NHA NE S I II D ata
. . . . . . . . . . . . . . . . . . . . . . . . . . 11 -4 1 1
. 3 RE C O M M EN D A T I ON S
......................................... 11 -5 1 1
. 4 RE F E REN C E S F O R C H A P T E R 1 1
................................ 11 -5

## LIST OF TAB LES Table 11-1. Smoothed Percentil es of W eight (I n Kg) by Sex And Age: Statisti cs From NC HS And Data From Fels Research Institute, Birth t o 36 Months
. . . . . . . . . . . . . . . . . . . 11 -7 Table 11-2. Weight in Kilograms For Males 2 M onths-19 Years of Age– Number Examined, Table 11-3. Weight in Kilograms For Females 6 Months-19 Years of Age– Number Examined,

Table 11-5. Body Weight Estimates (in kilogr ams) by Age and Gender, U.S. Population 1988-94 Table 11-7. Mean Body Weight (kilogr ams) by Age and Gender Across Multipl e Surveys Table 11-8. Mean and Percentil e Body W eights (kg) Derived from NHANES III (All Childre n) Table 11-9 Mean and Percentil e Body W eights (kg) Derived from NHANES III (Male Chil dren) Ta ble11 -10 . M ean an d P erc entil e B od y W eights(kg ) D eri ve d f rom NHAN ES III(F em ale Mean, and Select ed Percenti les, by Age Category: United States , 1976-1980 a


## . . . . . 11 -8 Mean, and Select ed Percenti les, by Age Category: United States , 1976-1980 a


## . . . . . 11 -9 Ta ble11 -4. St ati sti cs f or P rob ab ili ty P lot Re gre ssi on An aly ses : N aturalLo g o f B od y W eights 6 M o nth s t o 2 0 Y e ar s o f A g e ............................................ 11-10

.................................................................. 11-11 Table 11-6. Body Weight Estimates (in kilogr ams) by Age, U.S. P opulation 1988- 94
. . . . 11-12

.................................................................. 11-13

.................................................................. 11-14

.................................................................. 11-14 C h i l dr e n )
.......................................................... 11-15 Table 11-11. Summ ary of Recomm ended Values for Body Weight
. . . . . . . . . . . . . . . . . . 11-15 Table 11-12. Confidence in Body Weight Recomm endations
. . . . . . . . . . . . . . . . . . . . . . . 11-16

LIST OF FIGURES Figure 11-1. Weight by Age percenti les for Girls Aged Birth-36 Months
. . . . . . . . . . . . . . 11-17 Figure 11-2. Weight by Age Percenti les for Boys Aged Birth-36 Months
. . . . . . . . . . . . . 11-18 Figure 11-3. Mean Body W eight Esti mates, U.S. Population, 1988-94
. . . . . . . . . . . . . . . 11-19 Figure 11-4. Medi an Body W eights Esti mates, U.S. Population, 1988-94
. . . . . . . . . . . . . 11-20

## 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 31 1 1 . BODY W EI GH T S TUDI ES
1 1 . 1 I NT RO DU CT I ON The average dai ly dose is a dos e that is typicall y normalized to the aver age body weight of the exposed populati on. The purpose of this sec tion is t o describe ke y published studies on bo dywe ight f or c hil dre n in thege ne ralU. S. po pu lation , a s d esc rib ed in t he Ex posu re F ac tor s Handbook (U .S . E PA , 1 99 7). Re co mm en de d v alu es are b ase d o n th e re su lts of the se s tudies
. 1 1 . 2 BODY W EI GH T S TUDI ES 11.2.1 Hamillet al., 1979 A N ati on al C enter fo r H ealth S tatistics (N CH S) Ta sk Fo rcethat in clu de d a cad emic investigators and re presentat ives from the Centers for Disease Contr ol (CDC) Nutrition Surve ill an ce P rogram sel ect ed , c oll ate d, int egrat ed , and de fine d a pp rop riate d ata set s to ge ne rat e gro wth c urv es f or t heag e inter va l f rom bir th t o 3 6 m onths(H amillet a l., 19 79 ). Thepe rce nti le curves were deve loped to asse ss the physic al growth of childr en in the U.S. and are ba sed on acc urate m eas ure m ents m ad e o n large , n ati on ally repre sentativesam ple s o f c hil dre n. Smoo the d percenti le curves wer e derived for body weightby age for all chi ldren and inde pendently for bo ys an d f or g irl s. Th e d ata us ed to c on str uc t th e cu rve s w erepro vid ed bytheFe ls Rese arc h Institute, Yellow Springs, Ohio. Thes e data came from an ongoing longitudinal study i n which anthropometric datafrom direct measurements are col lected r egularly from approximately 1,000 parti cip ants i n v ari ou s areas of theU. S. Th e N CH S u sed advanc ed statis tic al and co m puter tec hn olo gyto g en erate thegro wth c urv es. Ta ble11 -1 p res ents theperce nti les of we ight by sex and age. Figures 11- 1 and 11-2 presentpercenti le values of body weight gr ouped by age for bo ys an d f or g irl s, res pe cti ve ly. Li m itatio ns of thi s st ud y are that m ean bo dywe ight value s w ere not report ed and the dataare more than 25 years ol d. However, this study doe s provide body we ight data f or inf ants l ess than 6 m onths old , whic h are l ackingin many o the r st udies
.

11.2.2. National Center for H ealth Stati stics, 1987 Statist ics on anthr opometric measurem ents, incl uding body weight, for the U.S. population were collect ed by NCHS through the second National Health and Nutri tion 11 -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 31 Ex aminatio n S urv ey(N HA NE S I I). NHAN ES II w as c on du cte d o n a natio nw idepro ba bil ity sam pleof 27 ,8 01 pe rso ns ag ed 6 m onths to 7 4 y ear s f rom theciv ili an , n on ins tit uti on ali zed po pu lation of theUn ite d S tat es. A t otal of 20 ,3 22 indivi du als in t hesam plewe re i nte rvi ew ed an d e xam ine d—a re sp on se rateof 73 .1 pe rce nt. Th e su rve y b eg an in F eb ruary 1 97 6 and wa s co m ple ted in F eb ruary 1 98 0. Th e sam plewa s se lec ted so that ce rta in s ub gro up s th ou ght to beat high ri sk of m aln utriti on (pe rso ns wi th l owinc om es, pre sch oo l ch ild ren , and theeld erly) w ere oversampled. The estimates were weighte d to reflect national popul ation est imates. The we ightin g w as a cco m pli sh ed byinf latingex aminatio n re su lts fo r ea chsu bje ct b y th e re cip roc al of

sel ection pro ba bil iti es a dju ste d to acc ount f or t ho se who we re n ot e xam ine d, an d-p os t strati fying by race, age, and se x. The NHANE S II colle cted standard body measurements of sam ple subject s, including height and weight , that were made at vari ous times of the day and in different seas ons of the year. This te chnique was used because an ind ividual’ s weight may vary between winter and summ er and m ayfluc tuate w ithpatte rns of fo od an d w ate r intake an d o the r dailyactivi tie s (NCHS, 1987). Percentile data for childr en, by age, are pr esented in Tabl e 11-2 for males, and in T ab le 1 1-3 fo r f em ale s.
11.2.3. Burmaster and Crouch, 1997 Bu rm ast er and Crou ch(19 97 ) pe rf orm ed data ana lys is t o f it n ormal and logno rm al distri butions to the body weights of females and m ales aged 9 months to 70 years
. Ex posu re Factors Handbook (U .S . E PA , 1 99 7) u sed a p re- pu bli sh ed ve rsi on of thi s p ap er. Th e num be rs reported i n Table 11-4 are based on the final paper and vary sl ightly from those reporte d in the Exposure Factors Handbook
. Data u sed in t his an aly sis we re f rom thesec on d s urv eyof theNatio na l C enter fo r H eal th Statist ics, NHANES II, which included 27,801 pers ons 6 months to 74 years of age in the U.S. (B urmast er e t al ., 19 97 ). TheNHAN ES II d ata ha d b een statis tic ally a dju ste d f or n on -re sp on se and probabili ty of selecti on, and strat ified by age, sex, and r ace to reflec t the enti re U.S. po pu lation pri or t o repo rti ng . B urmast er and Crou chco nd uc ted explo rat ory an d q uanti tativedata analyses and fitnormal and lognormal distributi ons to percent iles of body weights of chil dren, tee ns , and ad ult s as a f un cti on of ag e. Cum ulativ e dist rib uti on fu nc tio ns we re p lotted fo r f em ale an d m alebo dywe ights o n b oth lin ear an d lo garithmic s cal es.
11 -2

## 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 maxim um likelihood estimation was used to fitlognormal distribut ions to the data. Li ne ar and qu adratic r egres sio n line s w erefi tte d to thedata. A n um be r of go od ne ss- of -f

it m eas ure s w ereco nd uc ted on data g en erated
. Theinv estigator s f ound that lo gn ormal distri butions give s trong fits to the data for each gende r across a ll age groups
. Statist ics for the lognormal probability plots for chil dren aged 9 months to 20 years ar e presente d in Table 11-4. These data can be used for further anal yses of body weight distr ibution (i .e., applicat ion of Mo nteCarlo an aly sis ). Therea de r is ref err ed to t heori gin al s tud y f or a m orede tai led descript ion.
11.2.4 U.S. EPA, 2000 EPA’s Off ice of Water has estimated body weights for chil dren by age and genderusing data from NHANES III, which was conducted from 1988 to 1994. NHAN ES III coll ected body weight data for appr oximately 15,000 children be tween the ages of 2 months and 17 years. Ta ble11 -5 p res ents thebo dywe ight es tim ate s in kil ogram s b y a gean d g en de r. T ab le 1 1-6 sh ow s th e b od y w eight e sti m ate s f or inf ants und er t heag e o f 3 m onths ; F igu res 11 -3 and 11 -4 co m pare t hebo dywe ights (m ean an d m edian) of m ale s an d f em ale s o f v ari ou s ag e grou ps , respecti vely. Th e li m itatio ns of the se d ata arethat th e d ata we re n ot ava ila blefo r in fants un de r 2 months old, and that the dat a are roughl y over 12 years ol d. W ith the upward trends in body we ight f rom NHAN ES II ( 19 76 -19 80 ) to NHAN ES III , th e d ata in T ab les 11 -5 and 11 -6 may un de res tim atecurre nt b od y w eights
. A dju stm ent f act ors m aybene ed ed to u pd atetheestim ate s from 1988-1994 data to the present. However, the data are national i n scope and repr esent the general chi ldren’s popul ation.
11.2.5 Ogden et al., 2004 Og de n e t al . (2 00 4) ana lyz ed tre nd s in bo dywe ight m eas ure d b y th e N ati on al H eal th Examination Surveys II and I II (NHES II and II I), the Nati onal Health and Nutr ition Examination Surveys I, II, and III (NHANES I, II, and II I), and NHANES 1999-2002. The surve ys co ve red thepe rio d f rom 19 60 to 2 00 2. Ta ble11 -7 p res ents t hem eas ure d b od y w eights fo r vario us ag e grou ps as m eas ure d in NH ES an d NHA NE S. Po pu lation m ean s w erecal cu lat ed using sample weights to acc ount for variat ion in sampling for certai n subsets of the U.S.
11 -3

## 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 population. The dat a indicat e that mean body weight has incr eased over the period anal yzed. There is some uncertai nty inherentin such an anal ysis, however, because of changes in sampling m eth od s d uringthe42 ye ar tim e sp anco ve red bythestu die s. Be cau se t his stu dyis b ase d o n an an aly sis of NHAN ES data, its limitatio ns arethesam e as tho se f or t hat st ud y. Ho we ve r, i t do es ser veto i llu stratetheim po rtanc e o f t heus e o f tim ely data when ana lyz ingbo dywe ight.
11 .2 .6 EP A A na lys is o f N HANE S I II D ata The NHANE S III, 1988-94 was conduc ted on a nati onwide probabili ty sample of ap pro ximate ly 3 3, 99 4 p ers on s ag ed 2 m onths an d o lde r, o f whic h a pp rox im ate ly 1 5, 00 0 w ere ch ild ren . Thesurve y w as d esi gn ed to o btain n ati on ally repre sentativeinf ormati on on thehe alth an d nutriti on al s tat us of thepo pu lation of theUnite d S tat es t hro ugh inter vie ws an d dire ct phys ica l ex aminatio ns . Anum be r of anthrop om etrica l m eas ure m ents w eretaken fo r ea ch parti cip ant in thestu dy , in clu din g b od y w eight. Un it n onres po ns e to theho us eh old int erv iew was 14 percent, and an additional 8 percent di d not parti cipate i n the physical examinations (includi ng body weight measurements). Ce rta in s ubpo pu lation s w ereov ers am ple d to en sure a pre sp eci fi ed m ini m um sam plesiz e fo r ea chan alytic do m ain
. The se o ve rsam ple d s ub po pu lation s in clu dech ild ren , o lde r pe rso ns , Mex ican-Am eri can s, Af ric an -Am eri can s, an d p eo pleliv ingin c ert ain ge ograp hic are as. Sam ple data were ass igned weights t o account both for the disparity in sample sizes for these groups and for other inadequa cies in sampling, such as the presenc e of non-respondents. The wei ght for eac h p articipant w as c alc ulated as t herec iproc al o f t heparti cip ant' s p rob ab ili ty o f s ele cti on , w ith ad

jus tm ents f or o the r varia bil iti es in s am plingrat es s uc h a s ch an ge s m ad e to thesam plingrat es at the ti me of data coll ection. Using the data and the weighting fact ors from NHANES III, EPA calculated body weight statis tics for the s tandard age c ategorie s. Mean and perc entile va lues were cal culated usi ng the sampling weights provided for eac h individual in the dataset. The mean value for a given group wa s calculat ed us ingthefo llo wi ngfo rm ula :

11 -4

## 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 wh ere : = sample m ean; x i

## = the i th 

## observati on; w i 

## = sample weight assigned t o observati on x i 

## . Percentil e values were c alculat ed by first cal culating the sum of the weights for al l observat ions in a given group and multiplying this sum by the percent ile of inter est (e.g., multiplyi ng by 0.25 to determine the 25th pe rcentil e). The observat ions were then or dered from least to great est, and eac h o bs erv ati on wa s as signe d a cum ulativ e w eight, eq ua l to its own w eight p lus allwe ights lis ted be fo re theob ser vatio n. Th e f irs t ob ser vatio n li ste d w itha cum ulativ e w eight greater than the value ca lculate d for the percent ile of inter est was sele cted. Table 11-8 pres ents the per centile s of body weight for all chil dren by age cat egory. Tables 11-9 and 11- 10 present body weightby age category for m ale and female children, respecti vely. Limitations of these dataare thatthe data were not available for infants younger than 2 months old, and that the dat a are over 12 ye ars old. As with EPA’s ear lier ana lysis of NHANES II d ata wi th dif fe rent ag e categ ori es (U. S. EP A, 20 00 ), t hedata i n T ab les 11 -8 t o 1 1-1 0 m ay un de res tim atecurre nt b od y w eights du e to anob ser ve d u pw ard tre nd in b od y w eights (O gd enet al. , 2 00 4). Ad jus tm ent f act ors m aybene ed ed to u pd atetheestim ate s f rom 19 88 -19 94 data t o thepre sent. H ow ev er, theNHAN ES data r em ain theprinc ipal so urc e o f b od y w eight d ata co lle cte d n ati onwi defrom a largenum be r of su bje cts
. 1 1 . 3 RE COM M EN DAT I ONS The recomm ended values for body weightare summ arized i n Table 11-11. Table 11- 12 pre sents theco nf ide nc e ratin gs fo r bo dywe ight re co mm en datio ns . For infants (birth to 2 months), appropriate values for body weightmay be selected from Ta ble11 -1. Th esedata (pe rce nti les on ly) arepre sented fo r m alean d f em aleinf ants. Fo r ol de r inf ants and ch ild ren , m ean s an d p erc entil es maybesel ect ed from Ta ble s 1 1-8 (al l), 11 -9 (m ale s) an d 1 1-1 0 (f em ale s).

11 -5

## 1 11. 4 R E F E R E N C E S F O R C H A P T E R 11 2 3 4 5 B ur m as t er , D
. E. ; C r ouch, E. A
. C
. ( 1997) Lognor m al di str i but i ons f or body w ei ght as a f unct i on of age f or m al es and f em al es i n t he U ni t ed St at es , 1976- 1980. R i sk A nal
. 17( 4) : 499- 505. 

## 6 7 H a m ill , P .V .V .; D riz d , T .A .; Jo h n so n , C .L .; R e e d , R .B .; R o c h e , A .F .; M o o re , W .M
. (19 7 9 ) P h y sic a l g ro w th : N at i onal C ent erf or H eal t h St at i st i cs Per cent i l es . A m er i can J. C l i n. N ut r . 32: 607- 609. 

## 8 9 10 11 12 13 N a tion a l C e n te r fo r H e a lth S ta tistics (N C H S ) (1 9 8 7 ) A n th ro p o m e tric re fe re n c e d a ta a n d p re v a le n c e o f o v e rw e ig h t, U ni t ed St at es , 1976- 80. D at a f r om t he N at i onal H eal t h and N ut r i t i on Exam i nat i on Sur vey, Ser i es 11, N o. 238. H yat t svi l l e, M D : U
. S. D epar t m entof H eal t h and H um an Ser vi ces , Publ i c H eal t h Ser vi ce, N at i onal C ent erf or H eal t h St at i st i cs . D H H S Publ i cat i on N o. ( PH S) 87- 1688. 

## 14 15 O gd en, C
. L
. ; Fryar, C
. D
. ; C arr ol l , M
. D
. ; and Flegal , K
. M
. ( 20 04 )
. M ean B od y W ei gh t , H ei gh t , and B od y M ass I ndex, U ni t ed St at es 1960- 2002. A dvance D at a f r om V i t al and H eal t h St at i st i cs , N o. 347, O ct ober27, 2004. 

## 16 17 U
. S. D epar t m entof H eal t h and H um an Ser vi ces , C ent er s f or D i se as e C ont r ol and Pr event i on, N at i onal C ent er f or H eal t h S t at i st i cs. 

## 18 19 20 21 22 U .S . E P A (1 9 8 9 ) R isk a ss e ss m e n t g u id a n c e fo r S u p e rfu n d , V o lu m e I: H u m a n h e a lth e v a lu a tion m a n u a l. W a sh in g to n , D C : U .S . E n v iro n m e n ta l P ro te c tion A g e n c y , O ffic e o f E m e rg e n c y a n d R e m e d ia l R e sp o n se . EP A / 540/ 1- 89/ 002. 

## 23 24 25 U
. S. EPA ( 1997) Exposur e Fac t or s H andbook. W as hi ngt on, D C : O f f i ce of R es ear ch a nd D evel opm ent
. EPA / 600­ P- 95 / 00 2F. 

## 26 27 28 29 U. S
. E P A ( 2 0 0 0 ) M e mo r a n d u m e n t i t l e d : Bo d y we i g h t e s t i ma t e s o n NHAN ES I I I d a t a , r e v i s e d , Co n t r a c t 6 8
- C99- 242, W or k A ss i gnm ent0- 1 f r om B ob C l i ckner , W es t atI nc. t o H el en J acobs , U
. S. EPA dat ed M ar ch 3, 2000.



## 11 -6T a b le 1 1 -1
. S m o o th e d P e rc e n til e s o f W e ig h t (In K g ) b y S e x A n d A g e : S ta tistics F ro m N C H S A n d D a ta F ro m F e ls R es ear ch I nst i t ut e, B i r t h t o 36 M ont hs

Sex and A ge S m o o th e d P e rc e n til e a 5 th 1 0 th 2 5 th 5 0 th 7 5 th 9 0 th 9 5 th W e i g h t i n Ki l o g r a ms M a le B irth 2. 54 2. 78 3. 00 3. 27 3. 64 3. 82 4. 15 1 M o n th 3. 16 3. 43 3. 82 4. 29 4. 75 5. 14 5. 38 3 M ont hs 4. 43 4. 78 5. 32 5. 98 6. 56 7. 14 7. 37 6 M ont hs 6. 20 6. 61 7. 20 7. 85 8. 49 9. 10 9. 46 9 M ont hs 7. 52 7. 95 8. 56 9. 18 9. 88 10. 49 10. 93 12 M ont hs 8. 43 8. 84 9. 49 10. 15 10. 91 11. 54 11. 99 18 M ont hs 9. 59 9. 92 10. 67 11. 47 12. 31 13. 05 13. 44 24 M ont hs 10. 54 10. 85 11. 65 12. 59 13. 44 14. 29 14. 70 30 M ont hs 11. 44 11. 80 12. 63 13. 67 14. 51 15. 47 15. 97 36 M ont hs 12. 26 12. 69 13. 58 14. 69 15. 59 16. 66 17. 28 F e m a le B irth 2. 36 2. 58 2. 93 3. 23 3. 52 3. 64 3. 81 1 M o n th 2. 97 3. 22 3. 59 3. 98 4. 36 4. 65 4. 92 3 M ont hs 4. 18 4. 47 4. 88 5. 40 5. 90 6. 39 6. 74 6 M ont hs 5. 79 6. 12 6. 60 7. 21 7. 83 8. 38 8. 73 9 M ont hs 7. 00 7. 34 7. 89 8. 56 9. 24 9. 83 10. 17 12 M ont hs 7. 84 8. 19 8. 81 9. 53 10. 23 10. 87 11. 24 18 M ont hs 8. 92 9. 30 10. 04 10. 82 11. 55 12. 30 12. 76 24 M ont hs 9. 87 10. 26 11. 10 11. 90 12. 74 13. 57 14. 08 30 M ont hs 10. 78 11. 21 12. 11 12. 93 13. 93 14. 81 15. 35 36 M ont hs 11. 60 12. 07 12. 99 13. 93 15. 03 15. 97 16. 54

a Sm oot hed by c ubi c- spl i ne a ppr oxi m at i on. S o u rce : H am i l l et al. (19 7 9 ).



## 11 -7T able 11-2. W ei gh t i n K i l og r am s Fo r M al es 2 M on t hs-19 Y ears of A ge– N um ber Ex am i ned , M ean , and Select ed P ercent i l es, by A ge C at ego r y: U ni t ed S t at es, 1976- 1980 a

A ge N um berof Per sons Exam i ned M ean ( kg) P e rc e n til e
5 th 10 th 15 th 25 th 50 th 75 th 85 th 90t h 95 th b irth to < 1 m o n thb

- - - - - - - - - - - 1 t o <2 m ont hs b

- - - - - - - - - - - 2 to < 3 m o n th s 1 0 3 6 .6 5 .3 5 .5 5 .7 5 .9 6 .8 7 .2 7 .6 7 .8 8 .4 3 to < 6 m o n th s 2 8 7 7 .7 6 .3 6 .6 6 .7 7 .0 7 .7 8 .4 8 .9 9 .2 9 .6 6 to < 1 2 m o n th s 5 8 9 9 .4 7 .5 7 .9 8 .1 8 .6 9 .4 1 0 .2 1 0 .6 1 0 .9 1 1 .4 1 to < 2 y e a rs 6 1 3 1 1 .7 9 .4 9 .8 1 0 .1 1 0 .8 1 1 .7 1 2 .6 1 3 .1 1 3 .7 1 4 .5 2 to < 3 y e a rs 6 2 7 1 3 .7 1 1 .4 1 1 .8 1 2 .2 1 2 .6 1 3 .6 1 4 .6 1 5 .2 1 5 .8 1 6 .5 3 to < 6 y e a rs 1 5 5 6 1 8 .0 1 3 .7 1 4 .6 1 4 .9 1 5 .7 1 7 .5 1 9 .7 2 1 .0 2 2 .0 2 4 .0 6 to < 1 1 y e a rs 1 3 7 3 3 0 .7 1 9 .5 2 1 .1 2 2 .1 2 4 .0 2 8 .5 3 5 .2 4 0 .5 4 3 .5 4 8 .7 1 1 to < 1 6 y e a rs 1 0 3 7 5 5 .2 3 4 .0 3 6 .5 3 8 .7 4 2 .8 5 3 .0 6 3 .0 6 9 .4 7 4 .8 8 4 .3 1 6 to < 2 1 y e a rs 8 9 0 7 1 .8 5 4 .1 5 6 .6 5 8 .3 6 1 .8 6 8 .7 7 7 .9 8 4 .3 8 9 .7 1 0 1 .0 Note: 1 kg = 2.2046 pounds
. a Includes clothing weight , estimated as ranging from 0.09 to 0.28 kilogram. b No data available for infants less than two months old. So urce: N ati on al Center fo r H ealthS tatis tic s (1 98 7)
.



## 11 -8T able 11-3. W ei gh t i n K i l og r am s Fo r Fem al es 6 M on t hs-19 Y ears of A ge– N um ber Ex am i ned , M ean , and Select ed P ercent i l es, by A ge C at ego r y: U ni t ed S t at es, 1976- 1980 a

A ge N um ber of

Per sons Exam i ned M ean ( kg) P e rc e n til e
5 th 10 th 15 th 25 th 50 th 75 th 85 th 90t h 95 th b irth to < 1 m o n th b

- - - - - - - - - - - 1 t o <2 m ont hs b

- - - - - - - - - - - 2 to < 3 m o n th s 1 3 1 6 .0 4 .7 5 .1 5 .2 5 .6 6 .0 6 .5 7 .1 7 .3 7 .8 3 to < 6 m o n th s 2 6 9 7 .1 5 .8 5 .9 6 .1 6 .4 7 .1 7 .7 7 .9 8 .4 8 .7 6 to < 1 2 m o n th s 5 7 4 8 .8 7 .2 7 .5 7 .7 8 .0 8 .7 9 .4 1 0 .1 1 0 .4 1 0 .8 1 to < 2 y e a rs 6 1 7 1 1 .0 9 .1 9 .4 9 .6 9 .9 1 0 .9 1 1 .9 1 2 .6 1 2 .9 1 3 .4 2 to < 3 y e a rs 5 9 7 1 3 .4 1 0 .8 1 1 .2 1 1 .6 1 2 .1 1 3 .2 1 4 .6 1 5 .4 1 5 .6 1 6 .3 3 to < 6 y e a rs 1 6 5 8 1 8 .0 1 3 .3 1 4 .0 1 4 .5 1 5 .4 1 7 .2 1 9 .7 2 1 .1 2 2 .6 2 5 .1 6 to < 1 1 y e a rs 1 3 2 1 3 0 .6 1 9 .0 2 0 .5 2 1 .3 2 3 .4 2 8 .9 3 5 .0 3 9 .6 4 4 .3 5 0 .2 1 1 to < 1 6 y e a rs 1 1 4 4 5 3 .2 3 4 .1 3 7 .2 4 0 .4 4 5 .2 5 1 .6 6 0 .0 6 7 .2 7 0 .6 7 8 .2 1 6 to < 2 1 y e a rs 1 0 0 1 6 2 .2 4 6 .7 4 8 .2 4 9 .7 5 2 .2 5 8 .9 6 8 .3 7 4 .7 8 0 .8 9 2 .6 Note: 1 kg = 2.2046 pounds
. a Includes clothing weight, estimate d as ranging from 0.09 to 0.28 kilogram. b N o data av ail abl e f or

in fan ts le ssth an tw o month s ol d. So urce: N ati on al Center fo r H ealthS tatis tic s (1 98 7)
.



## 11 -9

### T a b le 1 1 -4
. S ta tistic s fo r P ro b a b ility P lo t R e g re ss io n A n a ly se s: N a tu ra l L o g o f B o d y W e ig h ts 6 M o n th s to 20 Y e a r s of A ge

A g e M id p o in t (y rs ) B e s t - Fi t Par a m e t e r s f or Lognor m a l D i s t r i but i on ( kg) M al es F em al es

2 

### μ a 2 

### F b 2 

### μ a 2 

### F b 

### 0. 75 1 .5 2 .5 3 .5 4 .5 5 .5 6 .5 7 .5 8 .5 9 .5 1 0 .5 1 1 .5 1 2 .5 1 3 .5 1 4 .5 1 5 .5 1 6 .5 1 7 .5 1 8 .5 1 9 .5 2. 23 2. 46 2. 60 2. 75 2. 87 2. 98 3. 13 3. 21 3. 33 3. 43 3. 59 3. 69 3. 78 3. 88 4. 02 4. 09 4. 20 4. 19 4. 25 4. 26 0. 132 0. 119 0. 120 0. 114 0. 133 0. 138 0. 145 0. 151 0. 181 0. 165 0. 195 0. 252 0. 224 0. 215 0. 181 0. 159 0. 168 0. 167 0. 159 0. 154 2. 16 2. 38 2. 56 2. 69 2. 83 2. 98 3. 10 3. 19 3. 31 3. 46 3. 57 3. 71 3. 82 3. 92 3. 99 4. 00 4. 05 4. 08 4. 07 4. 10 0. 145 0. 129 0. 112 0. 136 0. 134 0. 164 0. 174 0. 174 0. 156 0. 214 0. 199 0. 226 0. 213 0. 215 0. 187 0. 156 0. 167 0. 165 0. 147 0. 149

a 

### μ , - N atu ral l o g m ea n o f b o d y w eig h t ( k g ).

2 b 

### F 2 

### - N atu ral l o g stan d ard d ev iati o n o f b o d y w eig h t ( k g ). S o u rce : B u rm as ter et al. (1 9 9 7 ).



## 11-10Tabl e 11- 5. B ody W ei ght Est i m at es ( i n ki l ogr am s) by A ge a nd G ender , U
. S. Popul at i on 1988- 94 Age Sample Size Population Ma le and F em ale Ma le Fe m ale Me di an Me an Me di an Me an Me di an Me an 2- 6 month s 1,0 20 1,7 32 ,70 2 7.4 7.4 7.6 7.7 7.0 7.0 7- 12 m onth s 1,0 72 1,9 25 ,57 3 9.4 9.4 9.7 9.7 9.1 9.1 1 year 1,2 58 3,9 35 ,11 4 11 .3 11 .4 11 .7 11 .7 10 .9 11 .0 2 years 1,5 13 4,4 59 ,16 7 13 .2 12 .9 13 .5 13 .1 13 .0 12 .5 3 years 1,3 09 4,3 17 ,23 4 15 .3 15 .1 15 .5 15 .2 15 .1 14 .9 4 years 1,2 84 4,0 08 ,07 9 17 .2 17 .1 17 .2 17 .0 17 .3 17 .2 5 years 1,2 34 4,2 98 ,09 7 19 .6 19 .4 19 .7 19 .3 19 .6 19 .4 6 years 75 0 3,9 42 ,45 7 21 .3 21 .7 21 .5 22 .1 20 .9 21 .3 7 years 73 6 4,0 64 ,39 7 25 .0 25 .5 25 .4 25 .5 24 .1 25 .6 8 years 71 1 3,8 63 ,51 5 27 .4 28 .1 27 .2 28 .4 27 .9 27 .9 9 years 77 0 4,3 85 ,19 9 31 .8 32 .7 32 .0 32 .3 31 .1 33 .0 10 years 75 1 3,9 91 ,34 5 35 .2 35 .6 35 .9 36 .0 34 .3 35 .2 11 years 75 4 4,2 70 ,21 1 40 .6 41 .5 38 .8 40 .0 43 .4 42 .8 12 years 43 1 3,4 97 ,66 1 47 .2 46 .9 48 .1 49 .1 45 .7 48 .6 13 years 42 8 3,5 67 ,18 1 53 .0 55 .1 52 .6 54 .5 53 .7 55 .9 14 years 41 5 4,0 54 ,11 7 56 .9 61 .1 61 .3 64 .5 53 .7 57 .9 15 years 37 8 3,2 69 ,77 7 59 .6 62 .8 62 .6 66 .9 57 .1 59 .2 16 years 42 7 3,6 52 ,04 1 63 .2 65 .8 66 .6 69 .4 56 .3 61 .6 17 years 41 0 3,7 19 ,69 0 65 .1 67 .5 70 .0 72 .4 60 .7 62 .2 1 and ol der 31 ,31 1 25 1,0 97 ,00 2 66 .5 64 .5 73 .9 89 .0 80 .8 80 .3 1- 3 years 4,0 80 12 ,71 1,5 15 13 .2 13 .1 13 .4 13 .4 13 .0 12 .9 1- 14 years 12 ,34 4 56 ,65 3,7 96 24 .9 29 .9 25 .1 30 .0 24 .7 29 .7 15 -4 4 years 10 ,39 3 11 8,4 30 ,65 3 70 .8 73 .5 77 .5 80 .2 63 .2 67 .3 Source: U.S. EPA, 2000.



## 11-11Tabl e 11- 6. B ody W ei ght Est i m at es ( i n ki l ogr am s) by A ge, U
. S. Popul at i on 1988- 94

Age Sample Size Population Ma le and F em ale Median Mean 95% CI Newborn NA NA NA NA NA 1 Month NA NA NA NA NA 2 M onth s 24 3 40 8,8 37 6.3 6.3 6.1 -6 .4 3 M onth s 19 0 33 2,8 23 7.0 6.9 6.7 -7 .1 3 Months and Yo un ger 43 3 74 1,6 60 6.6 6.6 6.4 -6 .7
NA= N ot av ail abl e. CI = Confidence Interval s. So urce: U .S . EP A (2 00 0)
.



## 11-12Tabl e 11- 7. M ean B ody W ei ght ( ki l ogr am s) by A ge a nd G enderA cr oss M ul t i pl e Sur veys

G ender

and N H ES I I , 1963- 65 N H ES I I I , 1966- 70 N H A N ES I , 1971- 74 N H A N ES I I , 1976- 80 N H A N ES I I I , 1988- 94 N H A N ES 1999- 2002 A ge (years) N m ea n s t d. err. N m ea n s t d. err. N m ea n s t d. err. N m ea n s t d. err. N m ea n s t d. err. N m ea n s t d. err. M a le 2
- - - - - - 298 1 3 .6 0 .2 370 1 3 .4 0 .1 644 1 3 .6 0 .1 262 1 3 .7 0 .1 3
- - - - - - 308 1 5 .6 0 .1 421 1 5 .5 0 .1 516 1 5 .8 0 .2 216 1 5 .9 0 .2 4
- - - - - - 304 1 7 .7 0 .1 405 1 7 .6 0 .1 549 1 7 .6 0 .2 179 1 8 .5 0 .2 5
- - - - - - 273 2 0 .2 0 .2 393 1 9 .7 0 .1 497 2 0 .1 0 .2 147 2 1 .3 0 .5 6 575 2 2 .0 0 .1
- - - 179 2 2 .0 0 .3 146 2 2 .8 0 .4 283 2 3 .2 0 .6 182 2 3 .5 0 .4 7 632 2 4 .7 0 .2
- - - 164 2 4 .9 0 .4 150 2 4 .9 0 .4 269 2 6 .3 0 .4 185 2 7 .2 0 .4 8 618 2 7 .8 0 .2
- - - 152 2 6 .4 0 .3 145 2 8 .0 0 .6 266 3 0 .2 0 .8 214 3 2 .7 1 .0 9 603 3 1 .2 0 .4
- - - 169 3 1 .6 0 .8 141 3 0 .7 0 .6 281 3 4 .4 1 .0 174 3 6 .0 0 .7 10 576 3 3 .7 0 .3
- - - 184 3 4 .2 0 .6 165 3 6 .2 0 .7 297 3 7 .3 0 .9 187 3 8 .6 0 .8 11 595 3 8 .2 0 .3
- - - 178 3 8 .8 0 .8 153 3 9 .7 0 .9 281 4 2 .5 0 .9 182 4 3 .7 1 .1 12
- - - 643 4 2 .9 0 .4 200 4 4 .0 0 .8 147 4 4 .1 1 .0 203 4 9 .1 1 .1 299 5 0 .4 1 .3 13
- - - 626 50 0 .5 174 4 9 .9 1 .0 165 4 9 .5 1 .2 187 5 4 .0 1 .0 298 5 3 .9 1 .9 14
- - - 618 5 6 .7 0 .6 174 5 6 .3 0 .9 188 5 6 .4 0 .9 188 6 4 .1 3 .6 266 6 3 .9 1 .6 15
- - - 613 6 1 .6 0 .4 171 6 0 .3 1 .2 180 6 1 .2 1 .0 187 6 6 .9 1 .9 283 6 8 .3 1 .1 16
- - - 556 6 4 .8 0 .6 169 6 6 .9 1 .3 180 6 6 .5 1 .2 194 6 8 .7 1 .6 306 7 4 .4 1 .4 17
- - - 458 6 8 .1 0 .4 176 6 8 .6 1 .1 183 6 6 .7 0 .8 196 7 2 .9 1 .3 313 7 5 .6 1 .4 18
- - - - - - 124 7 4 .3 1 .3 156 7 1 .1 1 .2 176 7 1 .3 1 .7 284 7 5 .6 1 .1 19
- - - - - - 136 7 2 .6 1 .3 150 7 1 .8 0 .8 168 7 3 .0 2 .2 270 7 8 .2 1 .3

F e m a le 2
- - - - - - 272 1 3 .0 0 .1 330 1 2 .8 0 .1 624 1 3 .2 0 .1 248 1 3 .3 0 .1 3
- - - - - - 292 1 5 .0 0 .2 367 1 4 .8 0 .1 587 1 5 .4 0 .1 178 1 5 .2 0 .2 4
- - - - - - 281 1 6 .8 0 .2 388 1 6 .8 0 .2 537 1 7 .9 0 .3 191 1 7 .9 0 .3 5
- - - - - - 314 1 9 .7 0 .3 369 1 9 .4 0 .3 554 2 0 .2 0 .2 186 2 0 .6 0 .6 6 536 2 1 .5 0 .2
- - - 176 2 1 .6 0 .3 150 2 1 .9 0 .4 272 2 2 .6 0 .6 171 2 2 .4 0 .5 7 609 2 4 .2 0 .2
- - - 169 2 4 .3 0 .4 154 2 4 .6 0 .5 274 2 6 .4 0 .8 196 2 5 .9 0 .5 8 613 2 7 .5 0 .2
- - - 152 2 7 .5 0 .5 125 2 7 .5 0 .4 248 2 9 .9 0 .6 184 3 1 .9 1 .2 9 581 3 1 .4 0 .4
- - - 171 3 2 .0 0 .6 154 3 1 .7 0 .7 280 3 4 .4 1 .2 183 3 5 .4 0 .7 10 584 3 5 .2 0 .4
- - - 197 3 3 .8 0 .6 128 3 5 .7 0 .6 258 3 7 .9 1 .2 164 4 0 .0 1 .0 11 525 3 9 .8 0 .4
- - - 166 4 1 .2 0 .8 143 4 1 .4 0 .9 275 4 4 .1 1 .1 194 4 7 .9 1 .3 12
- - - 547 4 6 .6 0 .4 177 4 6 .7 1 .0 146 4 6 .1 0 .9 236 4 9 .0 1 .2 316 5 2 .0 1 .1 13
- - - 582 5 0 .5 0 .5 198 5 1 .8 1 .0 155 5 0 .9 1 .2 220 5 5 .8 1 .6 321 5 7 .7 1 .4 14
- - - 586 5 4 .2 0 .4 184 5 4 .6 1 .0 181 5 4 .3 1 .0 218 5 8 .5 1 .4 324 5 9 .9 1 .0 15
- - - 503 5 6 .5 0 .5 167 5 6 .6 0 .9 144 5 5 .0 0 .8 191 5 8 .1 1 .1 266 6 1 .1 1 .7 16
- - - 536 5 8 .1 0 .7 171 5 6 .8 1 .1 167 5 7 .7 0 .9 208 6 1 .3 1 .4 273 6 3 .0 1 .2 17
- - - 442 5 7 .6 0 .6 150 5 9 .5 1 .6 134 5 9 .6 1 .0 201 6 2 .4 1 .2 256 6 1 .7 1 .2 18
- - - - - - 141 5 8 .2 1 .1 156 5 9 .0 1 .0 175 6 1 .2 1 .9 243 6 5 .2 1 .5 19
- - - - - - 130 5 9 .5 1 .4 158 5 9 .8 1 .0 177 6 3 .2 1 .9 225 6 7 .9 1 .2 N H ES =N ati o n alH eal thE x ami n ati o nS urv ey; N H A N ES =N ati o n alH eal th an d Nutri t i o nE x ami n ati o n S urv ey. Source: Ogden et al., 2004


## 11-13Tabl e 11- 8. M ean and Per cent i l e B ody W ei ght s ( kg) D er i ved f r om N H A N ES I I I ( A l l C hi l dr en)
A ge G r oup N m ean percentil es 5 th 10 th 15 th 25 th 50 th 75 th 85 th 90 th 95 th 2 to < 3 month s 23 4 6.3 4.8 5.2 5.4 5.7 6.3 6.9 7.3 7.4 7.8 3 to < 5 month s 55 6 7.4 5.9 6.2 6.4 6.7 7.4 7.9 8.6 8.9 9.4 6 to < 11 m onth s 11 63 9.1 7.3 7.7 7.8 8.3 9.1 9.9 10 .4 10 .7 11 .2

1 to < 2 years 12 30 11 .4 9.1 9.5 9.8 10 .2 11 .3 12 .2 12 .8 13 .3 14 .0 2 to < 3 years 12 24 13 .5 10 .9 11 .4 11 .9 12 .4 13 .4 14 .6 15 .3 15 .8 16 .3 3 to < 5 years 32 14 18 .0 13 .5 14 .3 14 .8 15 .6 17 .4 19 .7 21 .1 22 .2 24 .5 6 to < 11 years 26 94 30 .6 19 .2 20 .8 21 .6 23 .6 28 .8 35 .0 40 .0 43 .8 49 .2 11 to <1 6 years 21 81 54 .2 34 .0 36 .7 39 .5 44 .0 52 .0 61 .9 68 .1 72 .7 81 .4 16 to <2 1 years 18 91 67 .0 48 .0 50 .7 52 .5 56 .0 64 .1 74 .2 80 .5 85 .8 9 8 .3 N ot e: N o dat a a r e a vai l abl e f or per sons l es s t han 2 mont hs ol d. S o u rc e : E P A A n a ly sis o f N H A N E S III d a ta

Tabl e 11- 9 M ean and Per cent i l e B ody W ei ght s ( kg) D er i ved f r om N H A N ES I I I ( M al e C hi l dr en)
A ge G r oup N m ean percentil es 5 th 10 th 15 th 25 th 50 th 75 th 85 th 90 th 95 th 2 to < 3 month s 10 3 6.6 5.3 5.5 5.7 5.9 6.8 7.2 7.6 7.8 8.4 3 to < 5 month s 28 7 7.7 6.3 6.6 6.7 7.0 7.7 8.4 8.9 9.2 9.6 6 to < 11 m onth s 58 9 9.4 7.5 7.9 8.1 8.6 9.4 10 .2 10 .6 10 .9 11 .4

1 to < 2 years 61 3 11 .7 9.4 9.8 10 .1 10 .8 11 .7 12 .6 13 .1 13 .7 14 .5 2 to < 3 years 62 7 13 .7 11 .4 11 .8 12 .2 12 .6 13 .6 14 .6 15 .2 15 .8 16 .5 3 to < 5 years 15 56 18 .0 13 .7 14 .6 14 .9 15 .7 17 .5 19 .7 21 .0 22 .0 24 .0 6 to < 11 years 13 73 30 .7 19 .5 21 .1 22 .1 24 .0 28 .5 35 .2 40 .5 43 .5 48 .7 11 to <1 6 years 10 37 55 .2 34 .0 36 .5 38 .7 42 .8 53 .0 63 .0 69 .4 74 .8 84 .3 16 to <2 1 years 89 0 71 .8 54 .1 56 .6 58 .3 61 .8 68 .7 77 .9 84 .3 89 .7 1 0 1 .0 N ot e: N o dat a a r e a vai l abl e f or per sons l es s t han 2 mont hs ol d. S o u rc e : E P A A n a ly sis o f N H A N E S III d a ta



## 11-14Tabl e 11- 10. M ean and Per cent i l e B ody W ei ght s ( kg) D er i ved f r om N H A N ES I I I ( Fem al e C hi l dr en)
A ge G r oup N m ean percentil es 5 th 10 th 15 th 25 th 50 th 75 th 85 th 90 th 95 th 2 to < 3 month s 13 1 6.0 4.7 5.1 5.2 5.6 6.0 6.5 7.1 7.3 7.8 3 to < 5 month s 26 9 7.1 5.8 5.9 6.1 6.4 7.1 7.7 7.9 8.4 8.7 6 to < 11 m onth s 57 4 8.8 7.2 7.5 7.7 8.0 8.7 9.4 10 .1 10 .4 10 .8

1 to < 2 years 61 7 11 .0 9.1 9.4 9.6 9.9 10 .9 11 .9 12 .6 12 .9 13 .4 2 to < 3 years 59 7 13 .4 10 .8 11 .2 11 .6 12 .1 13 .2 14 .6 15 .4 15 .6 16 .3 3 to < 5 years 16 58 18 .0 13 .3 14 .0 14 .5 15 .4 17 .2 19 .7 21 .1 22 .6 25 .1 6 to < 11 years 13 21 30 .6 19 .0 20 .5 21 .3 23 .4 28 .9 35 .0 39 .6 44 .3 50 .2 11 to <1 6 years 11 44 53 .2 34 .1 37 .2 40 .4 45 .2 51 .6 60 .0 67 .2 70 .6 78 .2 16 to <2 1 years 10 01 62 .2 46 .7 48 .2 49 .7 52 .2 58 .9 68 .3 74 .7 80 .8 9 2 .6 N ot e: N o dat a a r e a vai l abl e f or per sons l es s t han 2 mont hs ol d. S o u rc e : E P A A n a ly sis o f N H A N E S III d a ta

Tabl e 11- 11. Sum m ar y of R ecomm ended V al ues f or B ody W ei ght Popul at i on Tabl e R ef er ence Sour ce b irth to < 1 m o n th See Tabl e 11- 1 H am i l l etal
. ( 1979)

1 t o <2 m ont hs 2 t o <3 m ont hs

S ee T ab l es 11 -9 (all ), 11- 10 ( m al es ) , and

11
- 11 ( f em al es) EP A ana l ysi s of N H A N E S III d a ta 3 t o <5 m ont hs 6 t o <11 m ont hs

1 t o < 2 ye ars 2 t o < 3 ye ars 3 t o < 5 ye ars 6 t o < 1 1 ye ars 1 1 t o < 1 6 ye ars 1 6 t o < 2 1 ye ars



## 11-15Tabl e 11- 12. C onf i dence i n B ody W ei ght R ecomm endat i ons Considerations Rationale Rating St udy El eme nt s • Lev el of pe er rev iew NHANES II I w as th e m ajo r s ourcefo r c ent ralte nd enc y and pe rce ntile values. This analy sis has not yet been published. Body weights of y oung in fants (0 -2 m onth s) are d erived from H am illet al . ( 19 79 ), a p ub lis hed st

ud

y wh ich re cei ved a hi gh le velof pe er rev iew Low for NHANES analysi s; High for y oung in fants • Accessibility NHANES III and Hamill et al. (1979) are available to the public. U.S. EP A (2 00 0) isav ail abl e u po n requ es t. High

• Rep ro du cib ili ty Resul ts can b e reprod uce d b y ana lyzin g NHA NE S IIdata, N HA NE S II I dat a, a nd

th e F elsRe se arc h Ins tit ut e d ata
. High

• Focus on factor of interest The studies focused on body weight , the exposure factor of intere st. High • Data pertine nt to US The data repre sent the U.S. population. High • Prim ary d ata Theprim ary d ata w erege nerate d f ro m N HA NE S IIan d I IIdata and F els s tu d i es , thu s th es e d at a are s ec o n d ar y. Medium

• Currency The data were coll ected between 1976-1980 for Hamill et al. and NHANES II. U.S. EPA (2000) and EPA’s analy sis of NHANES III us ing the new age groupings covered the y ears 1988-94. Ogden et al. (2004) covered the y ears 1960-2002. High for central t en d en cy; medium for percentil es • Adequacyof data collect ion

period TheN HA NE S IIs tu dy inc lu ded data col lec ted ov er a p eri od of

4 years . Bo dy w eight m eas urem ent s we re taken at vario us ti m es of th e d ay an d at di ff ere nt s eas on s of th e year . NHA NE S II I s tu dy in clu ded data col lec ted over a 7-y ear period. High

• Va lidity o f a pp ro ach Direc t b od y wei ghts w erem eas ured fo r b oth s tu di es . F or N HA NE S II , su

bgro up s at ris k f or

m aln utritio n w ereov er- sam pl ed. W eightin g w as accomplished byinflating examinat ion results for those not examined and were stratifie d by rac e, age, and sex. The Fels data are from an ongoing l o n g i tu d i n als tu dy wh ere th e d at a are co l l ec t ed r egu l arl y. High

• Studysize The sample size consisted of 28,000 persons for NHANES II. A uthor no ted in

H am illet al
. ( 19 79 ) t hat th e d ata s et wa s large. NHA NE S II I studyincluded 14,387 individua ls under the age of 21 years. High

• Representat iveness of the

population Data colle cted focused on the U.S. population for both studies. High

• Ch ara cte riz ati on of

varia bi lit y Al l s tu di es ch ara cte riz ed variab ili ty re gardi ngag e and s ex. A dditi on ally NHANES II characte rized race (for Blacks, Whites and total populations) and s am pl ed per so ns w ith lo w in com e. High

• Lack of bias in studydesign

(h igh ratingisde sirab le) There are no appare nt biases in the study designs for NHANES II. The studydesign for collecting the Fels data was not provided. MediumHigh • Measurement error For NHA NES II and III, m easurement error is expecte d to be low because bodyweights were performed in a m obile examinati on center using st andardize d p ro ced ures an d e quip m ent
. A ls o, m eas urem ent s we re taken at various times of the dayto account for weight fluctuat ions as a result of rec ent fo od or

w ate r int ake
. The aut ho rs of H am illet al
. ( 19 79 ) repo rt th at st ud

y dat a are bas ed on ac curatedirec t m eas urem ent s from an o n g o i n gl o n g i tu d i n als tu dy. High

Oth er El eme nt s • Number of s tudies There are two studies. Medium • Agree m ent be tw een res earche rs There is consistency among the studies. High OverallRating High 

## 11-16

## Figure 11-1. Weight by Age percenti les for Girls Aged Birth-36 Months S o u rce : H am i l l et al. (19 7 9 ). 

## 11-17

## Figure 11-2. Weight by Age Percenti les for Boys Aged Birth-36 Months S o u rce : H am i l l et al. (19 7 9 ).



## 11-18Fi gur e 11- 3. M ean B ody W ei ght Est i m at es , U
. S. Popul at i on, 1988- 94

So urce: U .S . EP A (2 00 0)
.



## 11-19Fi gur e 11- 4. M edi an B ody W ei ght s Est i m at es , U
. S. Popul at i on, 1988- 94

So urce: U .S . EP A (2 00 0)
. 

## 11-20