Evidence for Excellence is a periodic department showcasing new evidence-based practice guidelines and results of systematic literature reviews to help the nurse in practice.

Obesity among U.S. children continues to become more prevalent each year, one source indicating that as many as 17% are obese and nearly 34% are at risk for being overweight or obese. A recent nationwide survey indicates that parents expect the education system to take the primary responsibility in efforts toward a reduction in childhood obesity. A 2008 systematic review considers research published since 1990 that addresses curricular and environmental obesity-prevention programs in schools.

The review authors considered the quality of evidence in the 14 studies that met the criteria to be inadequate, overall, but they did note some qualitative trends.

* Sex was found to be a significant factor in the response to obesity interventions in school-girls tend to be "social learners" (that is, they learn better with and from others), whereas boys are more responsive to increased physical activity and improved diet.

* Although factors in the home environment appear to exert an influence on a child's weight, the researchers write that "interventions specifically including familial components have not been more effective in the primary or secondary prevention setting than those without specific targeting or inclusion of parents or families."

* Children ages seven to 10 respond better to obesity interventions than younger children do. (Children older than age 10 also responded well in the few trials that included them.)

The crux of the matter. Ideally, obesity-prevention programs in schools would be a cost-effective way to facilitate safe and lasting changes in diet and exercise, but there's insufficient evidence to guide their development and implementation.

MM