Few dispute that the increasingly overweight youth of the U.S. need to get moving, but many studies fail to take into account all of the many factors that can affect physical activity levels, social scientists say.

Wider-ranging research suggests that focusing on families and neighborhoods may increase youth physical activity.

Physical activity can be influenced by a variety of factors, including individual ones like gender and health behaviors like diet, according to Dr. Susan C. Duncan and her colleagues at the Oregon Research Institute in Eugene. Social and environmental factors, such as family support for physical activity and neighborhood recreational facilities, may also help determine how active a person is, the authors note in the July issue of the journal Exercise and Sports Sciences Reviews.

But most studies have not looked at how various factors interact on different levels, according to the report. The most appropriate way to study youth physical activity, according to Duncan’s team, is to look at factors on several levels - family, school, neighborhood and community.

As an example of so-called multilevel study, Duncan’s team cites a study of several hundred 10-, 12- and 14-year-olds and at least one parent of each child. The researchers’ aim was to look at youth physical activity on three levels - individual, family and neighborhood.

Results of the study indicated that while siblings tended to have similar physical activity levels, these levels varied from family to family. The study also showed higher levels of family support were related to increased physical activity.

“The findings suggest that interventions targeting families instead of simply individuals may yield more beneficial and enduring effects,” the authors conclude.

Another multilevel study looked at the effect of neighborhood factors on family physical activity. This preliminary study found that physical activity levels were fairly consistent among families living in the same neighborhood. However, there were significant differences from neighborhood to neighborhood.

“The findings of this study and others suggest that physical activity interventions targeted at the neighborhood level - in addition to individual-, family- and school-level programs - may be beneficial,” Duncan and her colleagues conclude.

More multilevel research like these studies is needed to make better sense of physical activity among people of all ages, the researchers conclude.

SOURCE: Exercise and Sports Sciences Reviews, July 2004.