title: Development of bioelectrical impedance analysis prediction equations for body composition with the use of a multicomponent model for use in epidemiologic surveys.
abstract: BACKGROUND
  Previous studies to develop and validate bioelectrical impedance analysis (BIA) equations to predict body composition were limited by small sample sizes, sex specificity, and reliance on reference methods that use a 2-component model.
  
  
  OBJECTIVE
  This study was designed to develop sex-specific BIA equations to predict total body water (TBW) and fat-free mass (FFM) with the use of a multicomponent model for children and adults.
  
  
  METHODS
  Data from 5 centers were pooled to create a sample of 1474 whites and 355 blacks aged 12-94 y. TBW was measured by dilution, and FFM was estimated with a multicomponent model based on densitometry, isotope dilution, and dual-energy X-ray absorptiometry.
  
  
  RESULTS
  The final race-combined TBW prediction equations included stature(2)/resistance and body weight (R(2) = 0.84 and 0.79 and root mean square errors of 3.8 and 2.6 L for males and females, respectively; CV: 8%) and tended to underpredict TBW in black males (2.0 L) and females (1.4 L) and to overpredict TBW in white males (0.5 L) and females (0.3 L). The race-combined FFM prediction equations contained the same independent variables (R(2) = 0.90 and 0.83 and root mean square errors of 3.9 and 2.9 kg for males and females, respectively; CV: approximately 6%) and tended to underpredict FFM in black males (2.1 kg) and females (1.6 kg) and to overpredict FFM in white males (0.4 kg) and females (0.3 kg).
  
  
  CONCLUSIONS
  These equations have excellent precision and are recommended for use in epidemiologic studies to describe normal levels of body composition.
authors.affiliation: Lifespan Research Center, Department of Community Health, Wright State University School of Medicine, Dayton, OH 45420, USA. shumei.sun@wright.edu
authors.forename: Shumei S
authors.initials: SS
authors.lastname: Sun
authors.forename: W Cameron
authors.initials: WC
authors.lastname: Chumlea
authors.forename: Steven B
authors.initials: SB
authors.lastname: Heymsfield
authors.forename: Henry C
authors.initials: HC
authors.lastname: Lukaski
authors.forename: Dale
authors.initials: D
authors.lastname: Schoeller
authors.forename: Karl
authors.initials: K
authors.lastname: Friedl
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Kuczmarski
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Flegal
authors.forename: Clifford L
authors.initials: CL
authors.lastname: Johnson
authors.forename: Van S
authors.initials: VS
authors.lastname: Hubbard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D044383:Black People; D001823:Body Composition / Q000502:physiology*; D015992:Body Mass Index; D001834:Body Water / Q000378:metabolism*; D002648:Child; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D016021:Epidemiologic Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012727:Sex Characteristics; D044465:White People