Cream of Wheat for breakfast, baloney or PB&J for lunch, beans with a ham bone in the crock pot and rice. Bananas, fruit cups and vegetable/fruit juice to get the rest of what my body needs. And I still have a few bucks for a cheap steak with eggs a couple of times a week. $40 a week for food is doable.
OOOOOOOOOR you could trim the fat from your budget and start clipping coupons DUmmie.
( I have to say I really miss the buzz of energy drinks tho. Have to make do with instant coffee. )