For obesity prevention, turn to your community.

A new study from the RAND corporation finds that adolescents from close-knit neighborhoods are less likely to become obese. The researchers define close-knit communities as those in which neighbors get along and are helpful to other families, and adults serve as role models for children and teenagers. Such "collective efficacy" was found to be more important in predicting childhood obesity in the study's neighborhoods than both ethnic/racial make-up and resident income level.

Older studies have shown that collective efficacy is predictive of crime level. Other health outcomes like cardiovascular disease and premature death have also been tied to low levels of collective efficacy in these neighborhoods.

The present research involved surveying almost 700 households in Los Angeles County for a total of 807 adolescents and 3,000 adults; 65 different neighborhoods were examined. The study found that adolescents who lived in neighborhoods with high levels of collective efficacy were less likely to be overweight and had a lower body mass index than peers in other neighborhoods.

In communities with low collective efficacy, adolescents were 52% more likely to be overweight than those living in neighborhoods with an average level of collective efficacy. These neighborhoods were also 64% more likely to be at risk for overweight.

The researchers point out that the predictive nature of collective efficacy in regard to adolescent obesity is not entirely understood, but they speculate that children in neighborhoods with high collective efficacy may be more likely to play outside rather than sit on the family couch snacking and watching TV. They note that people with a vested interest in their community may fight to establish and maintain certain aspects of these neighborhoods, for example more parks and less fast food restaurants.

In the nationwide fight against obesity, another important weapon is now added to the arsenal. In addition to maintaining healthy dietary habits and scheduling regular exercise, the study results empower us--if not obligate us--to band together in community groups supportive of physical activity among our children. Sports leagues, youth centers, and park clean-up efforts are just some of the ways to create such environments. Another is the American Running Association's community run-walk program. For more information and to obtain a starter kit for your neighborhood, please visit One-on-One Walk and Run [link].

(Social Sci. & Med., 2006, Vol. 62, No. 3, pp. 769-778)