title: Assessing the body composition of 6-17-year-old Black and White girls in field studies.
abstract: The purpose of the study was to develop ethnic-specific equations for fat-free mass (FFM) from selected anthropometric dimensions and bioelectrical impedance measures of resistance (R) and reactance (Xc) for use in the NHLBI Growth and Heath Study. Using dual-energy X-ray absorptiometry measures of body composition as the dependent variable and field measures of body composition by anthropometry and bioelectrical impedance as the explanatory variables, ethnic-specific prediction equations were developed on a sample of girls representing a wide range of ages and BMI. The equations were cross-validated using (1) the Prediction of Sum of Squares (PRESS) statistic and (2) an independent sample of 20 girls of each race from a study conducted at the National Institute of Child Health and Human Development (NICHD). Subjects were 65 White and 61 Black girls 6-17 years of age. The best race-specific equations for FFM each explained 99% and 97% of the variance in the White and Black girls, respectively. Root mean square errors (RMSE) ranged from 1.14 to 1.95 kg. The equation for Black girls used Stature2/Resistance (R), weight, and reactance (Xc) as predictor variables; the equation for White girls used Stature2/R, weight, and triceps skinfold thickness. The results indicate that (1) equations to predict FFM in girls should be ethnic-specific and that (2) accurate values for TBF and %BF can be calculated from the predicted FFM.
authors.affiliation: Division of Cardiology, Cincinnati Children's Hospital Medical Center, Ohio 45229, USA. morrj2@chmcc.org
authors.forename: J A
authors.initials: JA
authors.lastname: Morrison
authors.forename: S S
authors.initials: SS
authors.lastname: Guo
authors.forename: B
authors.initials: B
authors.lastname: Specker
authors.forename: W C
authors.initials: WC
authors.lastname: Chumlea
authors.forename: S Z
authors.initials: SZ
authors.lastname: Yanovski
authors.forename: J A
authors.initials: JA
authors.lastname: Yanovski
mesh_terms: D000293:Adolescent; D044383:Black People; D001823:Body Composition; D002648:Child; D005260:Female; D006801:Humans; D015999:Multivariate Analysis; D012044:Regression Analysis; D012107:Research Design / Q000592:standards*; D044465:White People