You want to lose weight? Live near a supermarket -- but far away from restaurants.

In a recent study, researchers at the State University of New York at Buffalo looked at women's body mass index in relation to their neighbourhoods' food amenities.

They found that women who lived near a supermarket tended to have a lower body mass index, meaning they were less likely to be obese, than those closer to a convenience store. Most convenience stores don't offer healthy foods such as fresh fruit and vegetables or whole-grain products.

And the researchers found that residing near restaurant row was associated with widening waistlines. "The greater number of restaurants within a five-minute walk, the higher the woman's BMI," explains study author Samina Raja, associate professor of urban and regional planning at SUNY Buffalo.

The study, published last month in the Journal of Planning Education and Research, looked at 172 women in Erie County, N.Y., who lived in urban, suburban and exurban areas.

The upshot of the study is not that people should pack up and move, but that public policy planners need to consider the food environment.

"In preparing master plans," says Raja, "they need to think not just about economic development or an abstract quality of life, but the impact on people's ability to eat well."

In North America, obesity has long been seen as an individual's choice, as a lack of willpower, not as a public policy issue. But as obesity rates have increased, researchers are re-examining the issue.

This study adds weight to the argument that obesity is a problem of access and equality, says Wayne Roberts, the recently retired manager of the Toronto Food Policy Council, part of Toronto Public Health. "The problem of obesity is not just the result of an individual's decision. The decision is determined by the environment."

Roberts is one of the authors of "Cultivating Food Connections," the newest Toronto Food Strategy project report, which will be presented to city council early next year, he says. The report states that access to healthy food is a city issue and should be the mandate of every department, explains Roberts.

At FoodShare Toronto, executive director Debbie Field says that access to healthy food in this city varies significantly. The Parkdale area, for example, has numerous fruit and vegetable shops, she points out, while many Scarborough areas offer only convenience stores in strip malls.

Her non-profit group is affiliated with the Good Food Markets program which sells affordable fruits and vegetables weekly in 17 neighbourhoods where healthy produce is not available.

"We think we're at the point where planners should be citing healthy grocery stores just as they do schools when talking about development," says Field.