While exercise is a great way for white girls to fend off obesity, it's hardly effective among blacks, a study finds. Researchers reviewed 1,148 adolescent girls, comparing their physical activity and obesity rates. They found that white 12-year-olds who moved more—falling into the top half of researchers' exercise spectrum—cut their chances of obesity by age 14 by 85%. For African-American girls, however, that figure was just 15%, the Los Angeles Times reports.
Experts tie the findings to research suggesting exercise is slower to oxidize fat in black women. The findings bring new challenges for health advocates battling obesity in young people, creating "yet another barrier to what might already feel like a struggle," says one. Their tactics may have to change, researchers say. While pushing exercise remains important, "using different approaches (e.g. emphasizing reductions in energy intake) may be necessary to prevent obesity in black girls," notes one.