The link between food deserts and health is far from absolute, so maybe it's time to focus on the bottom line: more affordable food.
Rahm Emanuel has made eradicating "food deserts" a priority of his mayoral reign. He recently met with grocers in Chicago to discuss bringing affordable, nutritious food to under-served, low-income neighborhoods. That food access may come in the form of Walmarts, Walgreens, and Aldis.
Emanuel isn't alone in his mission to bring air-conditioned supermarket abundance to so-called "food deserts"—those vegetable-parched regions that are low on groceries and high on poverty. (The United States Department of Agriculture defines food deserts as places where at least a fifth of the population lives at or below the poverty line, and a third of the population lives more than a mile from a large grocery store). In fact, encouraging the proliferation of grocery store chains is a central part of the national strategy to address America's growing obesity problem: Just look at Michelle Obama's high-profile Let’s Move initiatives.
But maybe the solution isn't more supermarkets. An overemphasis on huge grocery stores can overlook the role of smaller mom-and-pop shops, many of which offer an ample selection of competitive priced goods. And despite some data linking obesity and supermarket proximity, we don't all choose to shop at the closest supermarket. As Adam Drewnowski points out [PDF], shoppers using the Supplemental Nutrition Assistance Program (food stamps) traveled an average of five miles to buy food—even though the closest grocery store was less than two miles away. This suggests that even low-income households don't choose foods based on proximity alone, and is a good indication of why addressing the food desert's twin—the transportation desert—is an equally important initiative.
Furthermore, as The Economist points out in a pithy recent piece, improved access to healthy food alone won't alter our consumption habits:
The unpalatable truth seems to be that some Americans simply do not care to eat a balanced diet, while others, increasingly, cannot afford to. Over the last four years, the price of the healthiest foods has increased at around twice the rate of energy-dense junk food.\n
Making healthier food more readily available might be part of the solution—whether that's healthier corner stores or mobile grocers. But it also needs to be more affordable. No doubt, Walmart has some bad practices. But, in this case, they could be on to something.