Hiya!
If you want to add a bit more complexity and coolness... maybe port over the "Food Point" system from Powers & Perils? (
Powers and Perils - P&P Rule Books ; you're looking for Book 1.3 ...it's the latest 'updated by the community' one ). [Oh, PS, yes, all totally legal; "we" got permission from Avalon Hill, TSR and then WotC...and even Richard Snider, the writer of the system, even posted there on occasions ...including his never-finished "2nd edition P&P"].
Short version: All food and drink has a Food Point ("FP") value. Typically 1/4, 1/2, and increments of 1. Food weighs, well, whatever the food weighs. Just put a crown of broccoli on the scale at the store; that's how much it weighs. Then you, the Referee, choose it's FP value. There are some already for the Referees use as a guideline. For example...
"Travel Ration ; Cost 1BB (Brass Bit) ; Weight 1/4 lb ; Description - 1FP of non-perishable, dried meat"
"Grain ; Cost 10 CC (Copper Coin) ; Weight 10 lb ; Description - 10FP of grain, bagged; usable by Characters and Herbivores"
"Ale ; Cost 3 BB ; Weight 1.5 lb ; Description - 1 quart of Ale (container extra), 1FP"
Anyway, each Character has a Weight (and Height, obviously). The weight of the PC (and race) tell you how many FP's per day the Character needs. For a 190lb Human, for example, needs 3FP/Day. The same weight, but a Dwarf, needs 1FP more (dwarves all need 1FP more), so 4FP/Day. If, for some reason, you have a portly Elf of 190lb, would only need 1.5FP/Day (elves and faerries need 50% of whatever their weight lists).
It would be dirt simple to do the same thing for D&D races and whatnot. One thing it does...it makes "huge characters" (re: the "My barbarian is 7' tall and weighs 427lb! GRRR!!!!!" ; "Ok, you need 10FP/Day, right?"

)...uh...lets just say that you end up with MUCH more reasonable characters (size wize) in the group.
PS: And yes, animals have FP/Day requirements too; a 'standard' Riding Horse would need 3FP/Day, and a well-trained, large War-Dog would need 2FP/Day, and that elf Ranger with the Hawk animal companion? Yeah, chances are the hawk is eating as much or more than the elf, needing 2FP/Day.
^_^
Paul L. Ming