Objective: To examine differences in body size, composition, and distribution of body fat among Hispanic, white, and Asian adolescents.
Research methods and procedures: This included cross-sectional data from the baseline sample of the Adequate Calcium Today trial. Participants included 180 Asian, 234 Hispanic, and 325 white girls 11.8 +/- 0.05 years of age from Arizona, California, Hawaii, Indiana, Ohio, and Nevada. Anthropometric and DXA measurements (Lunar Prodigy) were standardized across sites. Tanner pubertal stage was self-selected from line drawings. Physical activity was assessed by a validated questionnaire. Comparisons between ethnic groups were examined using contrasts in the context of a general linear model.
Results: Controlling for pubertal stage and study site only, Asians weighed less than Hispanics and were shorter than Hispanics and whites. Controlling for pubertal stage, height, weight, and study site, Asians had shorter leg lengths, smaller waist circumference, longer trunk lengths, more lean mass, less total fat mass, and less gynoid fat mass than Hispanics and whites; Asians had larger bitrochanteric width than whites; Asians had smaller DXA-derived android fat mass than Hispanics; and whites had smaller mean android/gynoid fat ratio than Hispanics. However, whites had a smaller android/gynoid fat ratio than both Asians and Hispanics in a model that adjusted for ethnicity, pubertal stage, bitrochanteric width, waist circumference, trunk length, log of physical activity, and study site, which explained 77% of the variation.
Discussion: Ethnic differences in fat distribution are partially explained by differences in skeletal dimensions.