Density of fast food restaurants may up obesity levels

NEW YORK (Reuters Life!) - If you're worried about an expanding waistline where you eat may be just as important as how much, according to a new study.

American researchers have found evidence to support the notion that fast food restaurants could be a contributing factor to the rising levels of obesity in the United States.

In a study that looked at the availability of restaurants, rather than what people ate, they discovered that eating out can have both a positive and negative impact on obesity, depending on the type of restaurant.

"We found that there was an association between the amount of full-service restaurants (with waiters) in the county one lives in and a lower risk of obesity," said Neil Mehta of the University of Pennsylvania.

"Conversely, we found that the increase in the number and the amount of fast food restaurants was associated with an increase in obesity," he added in an interview.

Mehta and Virginia Chang, of the University of Pennsylvania School of Medicine, used data from an annual telephone health survey and information from the 2002 U.S. Economic Census to examine the impact of the type and availability of restaurants on the weight of people who lived near them in 544 counties in the United States.

"We had a really large sample of over 700,000 respondents. Some of the prior studies were much smaller," Mehta, who reported the study in the American Journal of Preventive Medicine, explained.

The researchers found that areas with a higher total density of restaurants had a lower prevalence of obesity. But when they looked closer at the type of restaurant, a higher fast food density was associated with higher obesity.

"Because we are eating out so much, the type of restaurant we are eating in matters," according to Mehta.

About two-third of adults in the United States are overweight and almost one-third are obese, according to the U.S. Department of Health and Human Services. Being overweight or obese is a risk factor for a range of illnesses including diabetes, heart disease, high blood pressure, stroke and some type of cancer.

The researchers said they could not explain what it is about the two types of restaurants that could account for the difference in the prevalence of obesity.

"Future research needs to look into what happens when people eat in full-service, versus fat food restaurants," Mehta added.