The rising weight of our society is considered a major health epidemic, and obesity isn’t limited to adults. Today, one of five children is considered overweight. Because physical activity is one protective factor against obesity we can influence, researchers are investigating whether the schools our children attend might determine the amount of exercise they receive.

A new study of seventeen-thousand adolescents, published in the journal Pediatrics, found that the influence of schools clearly affected boys and girls differently.

First, the girls: Researchers found that black and Hispanic girls are less physically active than white girls, and that difference was, indeed, attributable to the schools they attended.

Black, white and Hispanic girls attending the same school displayed no difference in physical activity. Black and Hispanic girls generally attended poorer schools in which all girls had lower physical activity levels. But when school factors figured in, there was no longer a racial or ethnic difference in physical activity among girls.

In contrast, among boys, blacks and Hispanics were more physically active than whites attending the same schools. Overall, there were only minimal racial and ethnic differences in physical activity levels among boys. But within the same schools, both black and Hispanic boys had higher rates of physical activity than white boys.

The study shows the influence of schools clearly affects boys and girls differently. Researchers say if that’s the case, then school-based policy interventions aimed at increasing physical activity may need to use different strategies for boys than for girls.