In Madison, Wisconsin, the California Bay Area, Chicago, and in other places, innovative efforts are being taken to combat the problem of food deserts including "pop-up stores."

As classified by the United States Department of Agriculture (USDA), a food desert is "a low-income census tract where a substantial number or share of residents has low access to a supermarket or large grocery store." The USDA defines low-income census tract as having "a poverty rate of 20 percent or higher, OR 2) a median family income at or below 80 percent of the area's median family income." Low access is defined as having "at least 500 people and/or at least 33 percent of the census tract's population must reside more than one mile from a supermarket or large grocery store (for rural census tracts, the distance is more than 10 miles)."

Though the existence of food deserts is controversial to some, citing increased obesity in areas classified as food deserts as evidence that people living there must have access to affordable food, as many as 20 million people are believed to live in food deserts across the United States. The USDA began mapping out locations starting in 2009.

In Madison, Wisconsin, the non-profit Freshmobile, stocked with groceries from the Fresh Madison Market, opened on July 2. The trailer goes to low-income areas in the city and sells fresh foods and vegetables. Chicago's Fresh Moves is a one-aisle grocery store operating out of a donated bus in the West Side neighborhoods. And as for the vehicle that started the movement, a Bay Area group operated a biodiesel, solar-powered food truck that roamed Oakland neighborhoods selling wares.

While the efforts do seem to be having success, a study published earlier this year found that the simple existence of increased grocery stores does not help the problem of buying patterns. In addition to the increased grocery stores, consumers need to have affordable prices, good quality, and education.

Health tips help, but perhaps more important is the shopping environment. In many urban neighborhoods, the primary means to obtain foods is bodegas, which mostly sell packaged foods. Consumers are less likely to want to buy fresh foods at such neighborhood stores when items are bruised and old, when the atmosphere is less than idyllic (one expert cited complaints of one such store where people were drinking outside, providing an unwelcoming place for children), and when they do not have to maneuver around multiple aisles of packaged food in order to access the one aisle of fresh produce. In short, many low-income consumers want the same experiences that more affluent consumers have.

Experts also say to mix and match efforts for specific regions, due to cultural differences. What may work in one region, they say, may not in another.