It used to be that poor people did not have enough food, and sometimes we are still told that they don't, but instead it is the case that poor people are far more likely to belief, and then the claim was that poor people had plenty of food, but it was the wrong kind.

This gave rise to the notion of "food deserts", areas in dense urban areas where large grocery stores are too expensive or regulations are too onerous to stay in business and instead only small bodegas can survive. Get rid of the food deserts and poor people would be less obese, but a new paper in PLOS Medicine disputes the notion that making another change without any evidence will cure obesity. 

Government doesn't need evidence or a lack of it to enact policies, so reducing food deserts has been a priority of federal and state governments, often through public-private partnerships with corporations that happen to be owned by wealthy donors but the authors argue that the evidence supporting the elimination of food deserts as a strategy to reduce disparities in diet quality is weak. They discuss several other strategies that have the potential to lower disparities in diet quality more than eliminating food deserts. These strategies include education initiatives, changes in food assistance programs and taxing unhealthy food. 

The authors conclude, "[a]ddressing disparities in dietary quality may have important payoffs for the health of the population: we should promote policies and programs to support these changes while studying their effectiveness. These strategies do not preclude the elimination of food deserts but rather build a necessary infrastructure to promote healthy food consumption, in any neighborhood. Many reasons, such as economic and social justice, exist to support such initiatives and to remedy the lack of healthy food availability in low-income communities. We just should not expect the reduction of food deserts to have much impact on the prevailing health crisis of our time. We need to focus our efforts on initiatives more likely to improve dietary quality and decrease disparities."