I went to a rural boarding school, where students were not allowed to keep food in their rooms, nor eat between the familystyle meals in the cafeteria. I was ALWAYS hungry. There were penalties if you were caught with food. My solution was to put my stash in .50 cal ammo cans, in the woods. Bread, peanutbutter, restaurant-style jelly packets, dried fruit, nuts...you get the idea. I eventually added a tiny packstove, frypan, and pot to brew tea in.
This wasn't a school for people with eating disorders, just a very spare environ. The three tenets were self-reliance, simplicity of life, and directness of purpose.