Vegan - Restores more health from apples and other fruits, but cannot eat other foods.
Vegetarian - can also eat milk.
Traditional is the way it is in the game now.
Canibal - can collect meat from humanoid corpses, but cannot heal with other food
I like this idea ... maybe there can be even way for some races to consume raw meat for smaller amount of HP, than when cooked.
I dont know DnD so good, but for Half Orc, for example, i would expect raw meat to be consumable, even if maybe not as enjoyable as cooked.