title: Body composition estimates from NHANES III bioelectrical impedance data.
abstract: BACKGROUND
  Body composition estimates for the US population are important in order to analyze trends in obesity, sarcopenia and other weight-related health conditions. National body composition estimates have not previously been available.
  
  
  OBJECTIVE
  To use transformed bioelectrical impedance analysis (BIA) data in sex-specific, multicomponent model-derived prediction formulae, to estimate total body water (TBW), fat-free mass (FFM), total body fat (TBF), and percentage body fat (%BF) using a nationally representative sample of the US population.
  
  
  METHODS
  Anthropometric and BIA data were from the third National Health and Nutrition Examination Survey (NHANES III; 1988-1994). Sex-specific BIA prediction equations developed for this study were applied to the NHANES data, and mean values for TBW, FFM, TBF and %BF were estimated for selected age, sex and racial-ethnic groups.
  
  
  RESULTS
  Among the non-Hispanic white, non-Hispanic black, and Mexican-American participants aged 12-80 y examined in NHANES III, 15 912 had data available for weight, stature and BIA resistance measures. Males had higher mean TBW and FFM than did females, regardless of age or racial-ethnic status. Mean TBW and FFM increased from the adolescent years to mid-adulthood and declined in older adult age groups. Females had higher mean TBF and %BF estimates than males at each age group. Mean TBF also increased with older age groups to approximately 60 y of age after which it decreased.
  
  
  CONCLUSIONS
  These mean body composition estimates for TBW, FFM, TBF and %BF based upon NHANES III BIA data provide a descriptive reference for non-Hispanic whites, non-Hispanic blacks and Mexican Americans in the US population.
authors.affiliation: Department of Community Health, Wright State University School of Medicine, Dayton, Ohio, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Chumlea
authors.forename: S S
authors.initials: SS
authors.lastname: Guo
authors.forename: R J
authors.initials: RJ
authors.lastname: Kuczmarski
authors.forename: K M
authors.initials: KM
authors.lastname: Flegal
authors.forename: C L
authors.initials: CL
authors.lastname: Johnson
authors.forename: S B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: H C
authors.initials: HC
authors.lastname: Lukaski
authors.forename: K
authors.initials: K
authors.lastname: Friedl
authors.forename: V S
authors.initials: VS
authors.lastname: Hubbard
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000886:Anthropometry / Q000379:methods*; D001823:Body Composition; D002648:Child; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D009765:Obesity / Q000175:diagnosis*; D012737:Sex Factors