by ROB STEIN Washington Post

WASHINGTON — People who live in neighborhoods where they must drive to get anywhere are significantly more likely to be obese than those who can easily walk to their destinations, according to the first study to directly demonstrate that long-suspected link.

The study of nearly 11,000 people in the Atlanta area found that people living in highly residential areas tend to weigh significantly more than those in places where homes and businesses are close together.

The effect appeared to be largely the result of the amount of time people spend driving or walking. Each hour spent in a car was associated with a 6 percent increase in the likelihood of obesity and each half-mile walked per day reduced those odds by nearly 5 percent, the researchers found.

“ The kind of neighborhood where a person lives clearly has an effect on their health,” said Lawrence D. Frank, an associate professor of community and regional planning at the University of British Columbia, who led the study. The findings have national implications because the neighborhoods studied are representative of those across the country, Frank said.

“ These findings are clearly the strongest evidence to date that there’s a link between the built environment and obesity,” Frank said.

As the number of people who are overweight and obese has reached epidemic proportions in the United States, evidence has mounted that one of the main causes might be suburban sprawl. Such neighborhoods make walking or other kinds of exercise more difficult because they often lack sidewalks, road patterns that encourage travel on foot, or shopping areas that are accessible without cars.