BODY-COMPOSITION OF A YOUNG, MULTIETHNIC FEMALE-POPULATION

The study objective was to establish the range of body-composition val ues for a multiethnic female population (aged 3-18 y) by using dual-en ergy X-ray absorptiometry (DXA). Results for 313 females in three ethn ic groups [European American (white), n = 141; African American (black ), n = 101; and Mexican American (Hispanic), n = 68] are reported. Cha nges in the bone mineral content (BMC), lean tissue mass (LTM), fat ma ss, and percentage fat are presented as functions of age. Analysis of variance with age, weight, and height as covariates was used to evalua te differences among the three ethnic groups. BMC and LTM were higher in the black than the white females, but no significant difference in BMC or LTM was evident between the white and Hispanic groups. The rela tion between the BMC and LTM compartments was linear (r = 0.963, P < 0 .0005) and independent of age or ethnic classification. The Hispanic a nd black females had higher percentage fat values than the white group . When adjusted for body size, the Hispanic females continued to have significantly higher fat mass and percentage fat than the white female s in this study. Ethnic-specific equations for body composition as a f unction of age, weight, and height are given. In addition, the results for the white females in the present study were compared with DXA-der ived body-composition data for reference populations in other countrie s. We conclude that reference values of total body composition for you ng females need to be ethnic specific.