How Food Swamps, Food Security Led to Chronic Disease, Obesity

New data from the Urban Institute corroborates the link between food swamps—a caveat to food security—and chronic disease, particularly obesity.

The study specifically showed that areas with a higher density of retail food chains overlap with regions with the highest obesity rates. These findings give some credence to the concept of food swamps, which are defined in a 2020 CDC study as “environments saturated with unhealthy foods because of the large numbers of corner stores and fast-food outlets in them.”

To be clear, the report does not make a sweeping claim about the nutritional value of the food sold at every single retail food establishment. Moreover, this report focuses mostly on food establishments at which people purchase food to be prepared and eaten at home: grocery stores, dollar stores, warehouse clubs, convenience stores, gas stations, pharmacies, and other specialty stores.

But it still stands to reason that healthy behavior is influenced by environment, and that includes the various establishments at which people can buy their groceries. The Urban Institute researchers said this is a critical framework through which the healthcare industry can better understand obesity rates and healthy behavior change.

“[T]he focus on individual actions and tailored clinical management can obscure the ways in which the larger environment shapes the choices and opportunities that are available to all individuals, particularly those in communities where obesity is common,” they wrote.

“A critical part of the conversation about rising obesity and the related burden of chronic disease is about not the individual but what has happened in the environment all around us,” they added, citing previous research. “And a central feature of that environment is food and food access.”

The researchers used maps to look at where and how obesity rates overlap with density of retail food options for purchasing groceries.

By and large, places with higher obesity rates overlapped with areas with more retail food establishments. For example, obesity rates are concentrated in Southern counties, especially in Texas, Louisiana, Mississippi, Kentucky, and West Virginia. These counties have more food establishments per 1,000 residents than Western counties, where obesity rates are lower.

But it’s not necessarily having access to food establishments that sell groceries that influences obesity rates; rather, it’s the type of food establishments—i.e., ones that sell less nutritious food—that likely influences those obesity rates. The researchers said areas with higher obesity rates have a higher density of establishments that likely sell unhealthy foods: convenience stores, gas stations, dollar stores, and pharmacies.

In areas with a high percentage of residents with obesity, 65.5 percent of the food establishments are considered ones likely to sell unhealthy foods. That compares to 51.5 percent of the food establishments in counties with fewer residents with obesity.

Dollar stores, in particular, are more common in areas with a higher rate of obesity than in other counties.

Those data points are indicative of the relationship between income and food security. Although the researchers did not stratify food establishment type by average local income, there is something to be said about access to healthy food and income-based health equity. If low-income folks are buying food at a dollar store because the goods are less expensive, they have less access to nutritious food and may be set up for unequal health outcomes.

“The growth of dollar stores, particularly in lower-income areas, has prompted some policymakers to seek ways to constrain their growth,” the researchers explained. “Opponents have cited the lack of healthier food options and what is perceived as targeting of low-income communities for saturation, which may potentially limit the viability of other formats that could offer a wider variety of foods, such as small grocery stores.”

The researchers added some data outlining geographic disparities in retail food establishment type. Rural areas were generally more likely to have retail food establishments that mostly sell unhealthy foods; this was true across all counties regardless of obesity rate.

This information comes with some policy recommendations, with the Urban Institute researchers foremost lauding those set forth by the Biden Administration in its September 2022 White House Conference on Hunger, Nutrition, and Health. In particular, the researchers referenced incentives to attract healthier food outlets to underserved areas; investments in healthier food options in existing stores; and expanding SNAP nutrition incentive programs.

The Urban Institute researchers added that separate policies to limit the density of stores that sell unhealthy foods, like dollar stores, is a positive step forward. Upstream policies that impact food manufacturers themselves, plus agricultural policies, are also under the microscope to change what is on the shelves of existing stores.

The discussion around food swamps, not just food access, is a key caveat to understanding food as a social determinant of health. It is not enough to connect individuals with food, but rather create public policies to ensure individuals have access to affordable, nutritious food.