"Feeding himself has been the toughest part of the challenge to date. “I’ve not been able to buy enough food,” Mr. Brar said, as he walked through the Downtown Eastside to his latest residence, a small, depressing room inside a sketchy-looking hotel. “I’ve already lost eight or nine pounds.” He buys mostly cereals and grains, instant noodles, some fresh and frozen vegetables, tofu and milk.

Local activists trailing behind him said his luck is about to change, at least on the dietary front. No one need go hungry in the Downtown Eastside, said a man named Dave, himself a local welfare recipient. “There’s lots of free food down here,” Dave said. “The thing is, though, you have to line up for every meal, and that becomes a full-time job.”"

Even here, in the insanely expensive bay area, you can buy Costco spinach for 1.60$ per pound. bannanas 47c/lbs, rolled oats for 0.80$ per pound. etc. There's more examples of foods you can find that are cost effective.

Admittedly, you wouldn't be able to eat at restaurants, ever.