Alesdrobek: Normal difficulty. There isn't much food on the ground in my game, vast majority of my food came from the snails but that's almost all gone now. Have some bread left too but haven't found anything on the third level yet.
Enemies you kill there (spiders, the green-stuff-shooting guy, the mushroom) don't spawn any food.
And while it's true you cannot die of starvation, the problem is you cannot cast spells. And I guess you won't be able to swing weapons either since everything needs energy.
Then again maybe I'm worrying too much. But there's a clear lesson for me - if it takes me 10 or more minutes to figure out a puzzle, then reload saved game and do it again quickly.
I'm on the fifth floor.. or fifth basement? .. but food comes and goes pretty regularly. I'm a stockpiler, but every time it starts to get sort of low I find a cache. As long as you're not eating TOO much and not dilly dallying around, wasting time, food shouldn't be a problem. Then again, a lot of hunger will accrue if you need to wait to regen after battles. In other words, if you're getting hurt too much, get better! :)