Access to fast food restaurants has little impact on BMI, US study shows

08 Aug 2017 --- Living near fast food restaurants and supermarkets has little impact on someone’s body mass index (BMI), according to new research from Indiana University. Moreover, the researchers found that policies that are designed to reduce the number of fast food restaurants and increase the number of supermarkets are unlikely to reduce obesity, even though such policies may make it easier for people to find healthy foods.

The university researchers, including Coady Wing from Indiana University’s School of Public and Environmental Affairs, used results from the largest national study ever into the connection between residential environments and BMI.

Based on the results, changes in the availability of fast food restaurants and supermarkets near a person’s home were found not to be associated with reductions in BMI. In addition, no evidence was found that relationships between BMI and food outlets are different in neighborhoods with higher poverty levels.

“Fast food is generally not good for you, and supermarkets do sell healthy food, but our results suggest blocking the opening of a new fast-food restaurant or subsidizing a local supermarket will do little to reduce obesity,” Wing says.

The research team based its findings on the Weight and Veterans' Environments Study, a comprehensive database stretching from 2009 to 2014 that covered 1.7 million military veterans living in 382 US metropolitan areas. The researchers could assess how BMI changed with each veteran and match it with the locations of fast-food outlets and supercenters such as Target and Walmart stores.

The researchers calculated BMI by using height and weight measurements taken when the veterans visited a doctor, nurse practitioner or other provider. They added up the number of chain fast-food restaurants, supermarkets and other food outlets within one mile (1.6 km) and three miles of the person's residence. The researchers could use that information to track BMI changes, even when a person moved from one area to another or when a fast-food or other outlet opened or closed.

Previous research on this topic had been based on snapshots in time – known as cross-sectional data – and had suggested a link between food outlet access and BMI.

“We couldn't find evidence to support policies based on that presumed link,” Wing says. “Strategies like the healthy food financing initiatives some cities are pursuing could have benefits, for example reducing the saturation of unhealthy food sources in impoverished neighborhoods. But those policies alone aren't likely to lead to healthier BMI.”

An article summarizing the research and findings, “Geographic Accessibility of Food Outlets Not Associated With Body Mass Index Change Among Veterans, 2009-2014,” was published in the August edition of the peer-reviewed journal Health Affairs.

The US nutritional policy news comes during Kids Eat Right Month in the US, where one in five children is still obese. Recent US policy ideas have also included new nutritional labeling rules in chain food retailers and restaurants in New York City.