FRIDAY, Nov. 4 (HealthDay News) -- Most people who live near fast-food restaurants aren't at increased risk for weight gain, but women may put on a few extra pounds, according to a new study.

The findings challenge the widely held belief that living near fast-food restaurants and other unhealthy food outlets has contributed to the rapid rise in Americans' weight over the past few decades.

Researchers analyzed 30 years of data collected from participants in the Framingham Heart Study Offspring Cohort, which followed heart health and weight among people in and around Framingham, Mass., from 1971 to 2001.

No consistent relationship existed between access to fast-food restaurants and individual body mass index (BMI), a measurement of body fat determined by height and weight.

"We found that living near a fast-food restaurant had no effect on weight overall, with a minimal effect for women," study author Dr. Jason Block, who conducted the research as a Robert Wood Johnson Foundation Health & Society Scholar at Harvard University, said in a foundation news release.

"Our study shows that it's likely not where you live that matters, but what you eat," he added.

Block and colleagues found that predictors of higher BMI in both women and men included not smoking, older age, being married and consuming two or more alcoholic drinks per day. Among women, having a high school education or less was also associated with higher BMI.

"As we grapple with our obesity epidemic, this study shows that living next to a fast-food restaurant may not be a significant driver of weight gain over time," Block said. "There are clearly other factors that affect BMI more."

The study will be published in the Nov. 15 issue of the American Journal of Epidemiology.

More information

The U.S. Centers for Disease Control and Prevention outlines how to prevent weight gain.