The number of fast food outlets in poor and black neighborhoods may play a role in the obesity epidemic among residents of these areas, suggest the results of a geographical survey.

Obesity also has multiple genetic and behavioral causes, but easy access to fast food, which tends to be high in fat, may be a key environmental cause of obesity blacks and low-income individuals.

“More convenient access likely leads to the increased consumption of fast food in these populations,” says study author Jason Block, M.D., M.P.H., of Brigham and Women’s Hospital in Boston.

Americans in general are eating more fast food—the percentage of fast food calories in the American diet has increased from 3% to 12% over the last 20 years. “Despite stable physical activity patterns during the last 20 years, Americans are eating more, portion sizes have increased substantially, and inexpensive, high-calorie food is now ubiquitous,” Block notes.

Block and colleagues used computer software to map out and analyze the placement of New Orleans fast food restaurants such as Church’s Chicken, Pizza Hut, Subway, Burger King, and Taco Bell. They found that predominantly black neighborhoods had 2.4 fast food restaurants per square mile, while white neighborhoods only had 1.5 restaurants per square mile.

The study results appear in the current issue of the American Journal of Preventive Medicine.

Their study cannot prove that increased fast food access makes people eat more of it but “theoretically, more convenient access to fast food coupled with the decreased availability of healthy food in black and low-income neighborhoods may increase consumption of unhealthy foods,” Block says.

More from our magazine:  Beverage Battle: Cow's Milk Versus Alternatives like Soy and Almond Milk

Higher income and white neighborhoods have more supermarkets than poor and black neighborhoods, which tend to be served by smaller grocery or convenience-type stores. Research shows that supermarkets offer more healthy foods than grocery and convenience stores, according to the study.

Block and colleagues call for more research to examine whether fast food joints are a chicken or an egg contributing to obesity in black and low-income populations. It is possible that the market offers unhealthy foods in response to the preferences of these populations. Or, the food preferences in black and low-income neighborhoods may be shaped by what is available nearby, especially since residents of these communities often have less access to transportation.

“Likewise, because of limited financial resources, black and low-income populations may simply seek out the most calories for the lowest price,” Block adds.

Source: HBNS; American Journal of Preventive Medicine