How about a mod that makes your diet affect your Minecraft health and status. If you eat 3 food of one "category" in a row, you will gain an ability or handicap based on how healthy the foods are.
If you eat food like steak and chicken, your health and strength increases. (from the protein )
If you eat rotten flesh and spider eyes, your max health decreases and occasionally you become sick, making your screen go lightly green and you cant walk around properly. (using the nausea effect)
Eat carrots, and occasionally you will get night vision
Eat cookies and pumpkin pie a lot, and you will get overweight, and get slowed down occasionally
Bread, potatos and mushroom soup would act as effect removers, so that if you have eaten a lot of rotten flesh recently you can eat some bread in order to return to a "normal diet" state.
Eat a combination, and you will get combined abilities e.g. Eat mainly steak and carrots, you'll get night vision and increased health.
I have no idea how easy this would be to implement, but using potion effects for the different diets would make it much easier
