A new report suggests a simple strategy for combating obesity among young girls - increasing their gym time.

Giving first graders just one more hour per week of physical education than they had in kindergarten may effectively reduce obesity rates among girls who are overweight or at risk for becoming overweight, the report indicates.

“Our findings are important because they suggest one important public health strategy for combating obesity in the early years,” study co-author Dr. Ashlesha Datar, of the RAND Corporation, a nonprofit research organization, told AMN Health. “In fact, school-based physical education programs have the ability to serve a large population of children at risk for obesity.”

The US Centers for Disease Control and Prevention recommends that children participate in daily physical education classes, but research has shown that only a small minority of children do so. In many cases, less than half of the class time involves physical activity.

Various programs have been developed to improve physical education classes, however, and studies have shown that fitness in general among school-age youth can be improved and obesity may be reduced through targeted programs.

Rather than suggest another intervention or develop a new program, however, Datar and her co-author Dr. Roland Sturm, evaluated whether the physical education classes that are already in place in schools across the US may be used to prevent childhood obesity.

“Existing PE programs in schools have come under a lot of criticism because of their substandard quality,” Datar said. “In times of tight budgets, such programs may in fact be at risk for cuts in funding.”

“However, our study shows that there may be benefits to overweight girls from increased PE instruction in school,” she said. “Therefore, schools and educators should give PE programs another chance.”

Datar and Sturm followed 9,751 US kindergarten students for two years. On average, they found that kindergarten children spent less than one hour - 57 minutes - in physical education classes each week.

Gym time increased, however, between kindergarten and first grade. Sixteen percent of first graders received physical education instruction three to four times per week, compared with 12 percent of kindergarten children. More than one third of first graders spent 31 to 60 minutes a day in physical education classes, compared with about one fourth of kindergartners.

As physical education class time increased, body mass index (BMI) - a measure of weight in relation to one’s height - decreased among girls who were overweight or at risk for becoming overweight, the report indicates.

Increasing physical education instruction by just five hours per week between kindergarten and first grade would reduce the prevalence of overweight in girls by 43 percent, Datar and Sturm report in the September issue of the American Journal of Public Health.

Increased physical education class time did not seem to lead to similar BMI reductions among overweight boys or normal weight children.

One goal of the program “Healthy People 2010” is that children receive daily PE, Datar added. “Therefore schools need to mobilize the necessary resources to provide high quality physical education instruction to all children.”

“High quality physical education programs in schools are important because they not only help to check overweight in the present, but also inculcate health promoting habits in the early years that will reap benefits in the later years,” she said.

SOURCE: American Journal of Public Health, September 2004.