Periodically some public figure tries living on food stamps to prove a point. The latest such is Mayor Corey Booker, as reported here.
I think these are stunts, not signifying a thing. If you're going to eat an adequate diet on food stamps, you've got to cook. If you have to cook, you need a stove, you need utensils, and you need a stock of staples going into your week (i.e., flour, sugar, cooking oil, salt, etc..). The second prerequisite is buying in bulk. Buy big and buy cheap. Buy 10 pound bags of rice. Buy the bargains at the sales. Make big batches and freeze (assuming your refrigerator works).
Unfortunately living poor means you're more liable to unexpected adversity, and expected adversity, so you need to dip into your stocks and deplete the money and food stamps needed to buy big.