Start saving money on food by going dumpster diving- Seriously, this is the best choice for a poorfag in uni, stores all throw out perfectly fine food just because it expires in a day or two.
I used to do it all the time in my years at university and it worked out great. The worst that can happen is a security guard shooing you off, and even if he calls the cops they can't arrest you because you literally dindu nuffin.
https://www.youtube.com/watch?v=MJmCUSb-ZVo 