Neighborhood linked to obesity

Neighborhood amenities such as green space and a nearby grocery store may offer residents more than just curb appeal. Children who live in such neighborhoods are roughly half as likely to be obese as kids living in areas lacking these features, researchers report in two studies in the May American Journal of Preventive Medicine.

The research combines two health aspects of residential life that studies usually examine separately — neighborhood amenities that boost physical activity and ready access to a grocery store in place of fast food outlets.

The new studies “are important contributions to the needed evidence documenting the influence of environmental factors on people’s health, in particular obesity,” says Laura Kettel Khan, a nutritionist at the Centers for Disease Control and Prevention in Atlanta.

To assess those effects, Lawrence Frank, an urban planner and public health researcher at the University of British Columbia in Vancouver, and his colleagues rated the “built environment” of hundreds of neighborhoods in San Diego County, Calif., and King County, Wash., which includes Seattle. The researchers rated the number and quality of parks and a neighborhood’s “walkability” — whether its layout had a low level of sprawl, few cul-de-sacs and easy access to retail outlets.

The scientists gauged the nutrition component of the built environment by noting the presence or absence, within a half mile, of a grocery store that sold fresh fruits and vegetables. The number of fast food outlets in that range counted as a negative.

The scientists also collected health information on 681 children randomly identified in the two counties and scored each child’s neighborhood amenities.

In neighborhoods with high physical activity and nutrition scores, less than 8 percent of children ages 6 to 11 were obese, compared with nearly 16 percent in neighborhoods scoring poorly on both measures. Even after the researchers accounted for differences in sex, race, ethnicity, parents’ income, parents’ body mass index, parents’ employment status and other factors, the children in the high-scoring neighborhoods were 59 percent less likely to be obese than children in areas with poor ratings.

“This is a very promising area of research that will inform the way we think about cities and how to design neighborhoods,” says Jennifer Black, a nutritionist at the University of British Columbia who wasn’t involved in these studies. “We have a pretty strong sense that if it’s easier for people to safely and comfortably walk to the kinds of amenities they want, they will be more likely to be physically active and spend less time driving.”

Many older neighborhoods assessed in the study scored higher than those built more recently.  Newer strip mall developments on arterial roads, Frank says, often have plenty of parking in front but a wall behind that seals them off from nearby residents. “We’ve engineered out of our communities the ability to travel on foot to things nearby,” he says. “If we want to reverse the obesity epidemic, we need to reverse the way we’re building our communities.”