Food is part of the Provison which can be bought before entering a Dungeon.
It also can be gained through Dungeon Interactions while in a Dungeon.
Food is used for:
- Camping
- to eat when your party gets hungry (which requires 4 food if you do not have 4 food you need to starve and suffer 20% damage and stress)
- healing (which is not recommendet ,unless your hero is in Deaths Door, because it is very inefficient)
It is recommended to take at least 8 Food on a short mission and at very least 12 on an medium or long mission.
Picture of the Hunger Pop Up. http://hydra-media.cursecdn.com/darkestdungeon.gamepedia.com/5/55/2015-03-08_00001.jpg (If you now how to desplay it directly please change it ;)