Obesity and Mapping U.S. “Food Deserts”

by Eric Zuehlke, editor

A few months ago, I wrote about the correlation between lower income levels and higher obesity rates for women in the United States. The link is dramatic: 36 percent of women in the lowest income group are obese compared with 16 percent in the highest income group. Much of the research on this issue has highlighted the role of the availability of healthy food in neighborhoods. Now, Slate has published a nifty interactive map showing county-level data on the percentage of people with no car who live more than a mile from the nearest supermarket. Without easy access to supermarkets, many rely on fast-food or convenience store options for meals. This gets to a central issue in the obesity problem in America: the preponderance of cheap, convenient, but unhealthy food.

You’ll notice a striking resemblance when you compare Slate’s map with this county-level map on obesity rates in the U.S. from the Centers for Disease Control and Prevention:

Map courtesy of Centers for Disease Control and Prevention

Does the map of “food deserts”  tell the whole story of why obesity has become so common in the United States? No. I presume that some of the counties with high proportions of people without a car and far from supermarkets are rural and very sparsely populated (like those in Nevada, New Mexico, and Arizona, for example), skewing the point since there are few supermarkets in these counties. By showing county-level data, the map ignores the unique challenges of poor inner-city populations. And of course access to fruits and vegetables at a local market alone won’t necessarily change eating habits. Putting in farmers markets in every neighborhood wouldn’t automatically make everyone healthier and solve the obesity problem.

But access to a variety of food options, including fresh produce and nonprocessed food, does make a difference. Living far from a supermarket and with no car will certainty limit one’s options for healthy food. In my article, Max Schmeiser at the University of Wisconsin-Madison made an important point about the deeper reason for the correlation between poverty and higher obesity beyond just lower income levels: “While at first pass income may seem like an important determinant of obesity, individual behaviors, as well as the means with which to carry out healthy behaviors, primarily drive the relationship between income and weight. I believe the issue of greater obesity among low-income families relative to higher-income families is primarily driven by differences in information on good nutritional behaviors, cooking knowledge, and availability or access to healthy food. Higher income families…tend to live in neighborhoods with good grocery stores, or have access to cars to go to good grocery stores.” According to Slate’s map, many people in counties with high obesity rates simply don’t have easy access to good grocery stores.

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