Biracial differences in physical activity and body composition among women

Overweight among black females is almost two times as frequent as among white females. Genetics, caloric intake, and physical activity have been identified as possible explanatory factors. This study assessed the differences in physical activity and body composition in 76 white and 66 black adult females. Black women had significantly higher (p = .0001) percent body fat (32.2 +/- 7.1) than white women (27.7 +/- 6.5) with a similar difference in weight (4.4 kg) approaching significance (p = .055). Physical activity was assessed using a structured 24-hour recall instrument. A purposive sampling design was implemented to control for age, education and occupation. A summary physical activity value unit for the 24-hour period revealed a significantly greater mean value for white females (41.93 +/- 4.7) than for black females (40.01 +/- 3.9) suggesting white females were more physically active (p = .02) although this was not a function of biracial differences in play/recreation and exercise/sport type of activities. Although both black and white females were found to be sedentary (MET value < or = 2) over 90 percent of the time, black women are significantly more sedentary (p = .03). Biracial differences in discretionary non-exercise oriented activities may contribute to different rates of overweight observed between black and white women.