Study: Exercise helps black girls less than whites

LOS ANGELES – In a dispiriting finding for African-American girls and women, a new study finds that while engaging in high levels of physical activity is a good bet for preventing obesity in white adolescent girls, it does not give their black peers the same benefit.

The study, published in the Archives of Pediatrics and Adolescent Medicine, found that among black adolescent girls who moved the most at age 12, obesity at age 14 was nearly as likely as it was for those whose activity rates were far lower.

For white girls, by contrast, regular exercise at 12 appeared a nearly sure way to head off obesity at 14. That finding held even when the calorie intakes of an African-American youngster and her white counterpart were the same.

The authors, a pair of British researchers using data from a government health study that followed American adolescents for several years, said their findings point to a significant metabolic disadvantage for African-American girls hoping to maintain a healthy weight. They concluded that “obesity-prevention interventions may need to be adapted to account for the finding that black girls are less sensitive to the effects of physical activity” than whites.

In the national effort to stem a crisis of obesity in the United States, the state of African-American women stands out as a particular challenge. At 39.4 percent, their rate of obesity is the highest of any single ethnic or gender group measured. Four in five black women are overweight or obese when measured by the most widely accepted gauge of fatness, the body mass index, or BMI.