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.