Food can be acquired by killing rabbits with hunters, cutting grass or corn (castle mode) with a farmer, looting dead minions, opening loot chests, harvesting mushrooms, or traded from gold on a 1:1 ratio at the food stand. It can also be taken from and stored in food storage in castle mode.
In castle mode, corn can be planted on a meadow at the cost of 1 food.
Food can be used to recruit new minions and to heal injured minions at a campfire. The amound of food required for each new recruit scales with the number of minions in the tribe.
Food is an important resource throughout the game. In early game, it takes 18 food to have a full-sized 6-minion tribe. Furthur on in the game, it's advisable to have a full inventory of food as much as possible, in order to be able to instantly regenerate after losing minions in a battle and heal minions when the battle is over.
In the early game, at least some hunting is preferrable as it is one of the few ways to earn upgrades. Being able to visually differentiate poisonous mushrooms from edible mushrooms or having the mycology perk is useful as mushrooms are a low-risk and widely available source of food. Having the shock arrow perk to one-shot rabbits is also helpful.
Ideally in castle mode, food shall be gathered by dedicated resource squad. One 6-minion resource tribe should accommodate 2-3 full-sized attacking tribes.