Food is a very important factor in the game and how it plays out. Food has two functions: healing wounded heroes and leveling them up. Food is given to the player at a base rate of +3 for every door opened, this can be increased by creating a Food Replicator that will up the amount produced. Food can also be acquired by finding a banquet tables in random areas of the dungeon, these usually give between 6-10 Food.
Food can be used to heal a hero at a scaling cost in food as the hero gains levels. It is advised, during a fight, that you keep an eye on the top right of the screen where you can press the heal button and keep track of heroes' health.
Leveling up your characters requires a cost in food to be paid. There appears to be different amounts you have to spend on different heroes. The main amounts that are used in the game are 12-20-30-50, 13-21-35-60 going from level one to five.