I think eating can be real fun, until it's not soo realistic.
Some rogue-like games were mentioned below (IVAN and ADOM), there the system were quite realistic, you could buy tons of supply in your town before your journey, but half the way all of it were rotten, and you become sick and poisoned if you ate them. You always had to look for possible food sources, eatable corpses, and it was a real stress, because when you didn't find any you starved quickly.
I think in a pleasent food system you could find much more food in your enviroment than you need to, and you have to only buy some while you are doing 'the talking quests' in a city, but there's plenty of cheap taverns to supply you. Outside some food could be found on humanoid creatures (gnolls, trolls, ogres don't know what do you plan

) and some could be also acquired from plants.
I think making a complicated cooking system is rather a waste of development in a game like this, it could be done much more simplier way, for example: every ingredients can be good for eating, good for alchimistic reasons, or both. Imagine that water can be good to please your thirst, but it is also essential to most of the potions for an alchimist, the better alchemy skill you have the better you can recognise what is eatable among the strangest food sources, this doesn't actually mean handycap for a non-alchemist character, he could easily live from bread and water, or pork, that he know he can eat, but he rather not try Mossy Heket Tounges out
I can't really imagine a perfect way of hunting critters, so I'd rather leave it. (Imagine a sorceress hunting... Casting a meteor shower on a poor bunny

) Naturally you can't eat during combat, and foods can heal only a minimum amount of life, and there should be a limit how many can you eat in a row... (Many games made fun of overeating

)
It is really annoying when your character is a baby, and it must be fed in every 2 hours, I think eating once or twice a day is far enough, and every food should be a fed value, but keep it a really simple way... I only don't want to see a character well fed after a stawberry and after a chunk of pork meat as well
