Food is quite expensive. I thought WallMart was quite cheap.
for 50 bucks,
I would buy,
7 lbs cottage cheese, (no fat 50 gram protein) 50 cents each, 3,50
7 packs of fishmeals, different kind of tastes, 1,40 each, 48 gram protein each, 9,80
3 eggs a day, 21 a week, 30pack costs 3 dollar
7 blicks of tuna, 35 grams of protein each, 69 cents each, 4,20
3 chickenchest, about 300 gram each, 4,50
pound of meat, not my favourite 2,50
Total 27,50
Left 22,50 for some rice, oliveoil, pasta, legumes (beans, peas and lintels), not canned but fresh, maybe some potatoes, some whey, peanuts, a bread, around 10-15 euros on vegetables.
I don't buy these stuff every week, cause most of it you keep for two or three weeks.
50 dollars ain't much, but it doesn't become a matter of surviving.