At some point soon the interaction between dwarvish diet, exercise, climate, and survivability is going to create some incredible emergent behavior. Dwarfs in warm climates will be able to survive on booze, grains, mushrooms, and fresh fruits... but a dwarf in a cold or freezing biome is going to need to eat very fatty meats to stay alive, especially if he's outside a lot.
I'd love to see convective and conductive heat transfer (!) taken into account, even if you just calculate the steady-state temperature for each Z-level of each embark tile with a wind penalty for being outside. That way, dwarves living more than five or six Z-levels down (or in an embark tile with a magma source) would be warm most of the time, but dwarves on guard duty on a tile with the "outside" flag would be exposed to wind and surface temperatures. That way your craftsdwarves would end up eating a mostly-vegetarian diet because they would tend to be pampered and kept warm; meanwhile your warrior caste and woodcutters would eat lots of fatty meats to stay warm, and would end up becoming almost all muscle. The smiths and smelters would probably eat leaner meats and lots of fruit to stay hydrated, but their muscles would also end up looking like someone wrapped pink steel bridge-cables around a fire hydrant and then shrink-wrapped it in a bearskin.
...at which point you need to start asking yourself which kind of physique a female dwarf is going to select for her mate!
In any case, it's clear that eventually all of the vegetables will need separate ratings for
crispness and freshness, and the meats are going to need calories from protein and calories from fat.