Source: Food Environment Atlas, U.S. Department of Agriculture, Economic Research Service

Even within the borders of one of the world’s top agricultural countries, healthy food can be hard to come by. Many Americans reside in food deserts—communities where retailers offering fresh food are scarce but fast-food restaurants and convenience stores selling prepared foods can abound.

The top two maps at the right show the proximity of full-line grocers to two groups for whom healthy food is often difficult to procure: low-income households and those without access to a vehicle. Scientists are still exploring the links between food deserts and health by investigating how the nonavailability of fresh food may spur obesity, diabetes and other diet-related conditions. One 2006 study found an association between the presence of supermarkets and lower obesity rates. Convenience stores, on the other hand, were associated with higher rates.

“You always have to be careful about suggesting cause and effect,” says Mari Gallagher, whose Chicago consulting firm carries out case studies of local food environments. The relation between food and health is complex, and personal choice clearly plays a role. “But we do think that the environment, in a lot of different ways, matters,” Gallagher says. “You can’t choose healthy food if you don’t have access to it.”

This article was published in print as "High and Dry in the Food Desert."