Forcing people to do busywork eating and such is much like having weapons wearing out with a durability rating - its just irritating and exhausting, it isn't 'fun'. If a person wishes to roleplay eating food and such, let them. Don't force a mechanical issue on them. As for keeping food, I recommend it - the resting mechanic of eating, using a bedroll, using a fire, and removing armour, is all up a very accurate mechanic and works perfectly to my eyes.