Black/white differences in relative weight and obesity among girls: the Bogalusa Heart Study

Although black women have a higher prevalence of overweight and obesity than do white women, it is unclear if a similar pattern exists among youths. We therefore examined the development of black/white differences in relative weight and adiposity among 5 to 17-year-old girls.

Cross-sectional analyses of 4542 black and 4542 white girls who were examined between 1973 and 1994. Quetelet Index (kg/m(2)), Rohrer Index (kg/m;s(3)), and height-adjusted weight were used as measures of relative weight, and subscapular and triceps skinfolds as measures of adiposity. Breast development was used as an index of sexual maturation.

On average, black girls were 1 to 3 kg heavier than were similarly aged white girls, and before adolescence, they were 2 to 3 cm taller. After adjusting for differences in height, the mean relative weight of black girls was consistently greater than that of white girls only after age 13; furthermore, sexual maturation was a stronger correlate of relative weight among black girls than among white girls. Comparable differences were seen for the subscapular skinfold thickness, but white girls consistently had a thicker mean triceps skinfold than did black girls.

Sexual maturation should be considered in comparisons of relative weight and obesity among youths, and as compared with white girls, black girls do not have a higher mean relative weight until adolescence. The use of different indices of overweight and adiposity can lead to contrasting results, with simple comparisons of Quetelet Index tending to overstate the relative weights of taller children.