It's hard to keep your nutrition when you're poor.. so identifying superfoods can really help you. Things packed with all different kinds of vitamins, nutrients, and things your body needs can really save you.
- Rice is really good at keeping you full.. and it's not expensive. $15 here buys you a huge bag that lasts for effin' ever.
- Beans are a lifesaver when you're broke, so if you don't like them.. start.

To be honest, canned beans were never so great tasting to me. I found a bag of dry beans is cheaper, and you can make it taste like whatever you want. A crockpot will cook them to perfection every time.
- Spinach is like a wonder veggie, and a frozen bag is cheap and convenient. Spinach works as a filling, adding, topping, etc. Broccoli is also action packed.
- Eggs not only are versatile and cheap, but they provide protein (I usually found meat to be too expensive when I was really poor) but they've been proven to help you eat less calories (aka feel less hungry throughout the day. Important when you're broke.)
- Sweet potatoes aren't too expensive, taste great, and they provide you with all important vitamin A, something you could lack when not eating meat as well, and calcium. (Sweet potatoes put the yum in calcium.) They also contain vitamin C and potassium, so you'll cover bananas and oranges in one food. They also fill you up rather well :3
- If you're going to splurge a bit, I suggest it be on berries. They're so packed I'm not even going to bother naming what they contain. Trust me, they rock. Especially blueberries.
- Tea is another big thing. Teas are very cheap and provide a number of health benefits.
- Cheap cuts of meat. The local meat market carried cheap leftover-like cuts of meat from time to time, so I got them when ever I could.. and places like walmart sometimes carry things like the ground turkey pre-seasoned on sale. Kroger does this thing where they do 'manager discounts' when things are to expire soon.. so I usually cooked up that day whatever I found.
There's my two cents.