Living near a fast-food outlet doesn't make children fat, nor does living near a supermarket stocked with fresh fruits and vegetables make them thin, new research shows.

The study by Indiana University-Purdue University Indianapolis researchers examined a decade of data on more than 60,000 children aged 3 to 18. They compared the children's weights before and after fast-food outlets or supermarkets opened near their homes. The study found that living near a fast-food outlet had little effect on weight gain and living near a supermarket wasn't associated with lower weight.

The researchers also found that living near certain recreational facilities -- such as fitness areas, kickball diamonds and volleyball courts -- was associated with lower body-mass index (BMI). For example, an 8-year-old boy who lived near one of these facilities could reduce his weight by three to six pounds, the researchers calculated. But living near track and field facilities was linked to weight gain, they discovered.

The findings were published by the National Bureau of Economic Research.

"This study contradicts anecdotal information and provides scientifically verified insights into a wide range of variables that we hope will help physicians and public policy makers fight childhood obesity more effectively," study first author Robert Sandy, a professor of economics and assistant executive vice president of Indiana University, said in a school news release.

He noted that previous studies looked at a single moment in time, not a decade of data.

"Previous studies did not benefit from the wide range of information we acquired such as details of both sick- and well-doctor visits, changes in a child's address, annual food-service establishment inspection data, aerial photographs of neighborhoods and crime statistics over time. And other studies have not taken into account, as we did, families' self-selecting their locations -- for example, families who value exercise may be more likely to live near a park,"