Personally I was using "Survival", which adds need to eat and drink. To drink You must talk to pawnbroker about filling a jug with water (if You have one in inventory), and then You will recieve that jug filled with water enough for 10 uses. To eat, You must have a bowl, and a fork that You can get when exiting Census office. The bowl needs to be placed on the ground, then filled with ingriedients You want to eat and then "activated" with when holding a fork. When thirst and/or hungry, You lose fatigue. The more thirst/hunger, the more You lose, eventually You also start to lose health (when "dying of starvation/thirst). I think this is the best approach on this type of mods, becouse the penalty isn't too nasty but still needs to be avoided, as opposed to stats lowering in other mods.
The other mod is "http://planetelderscrolls.gamespy.com/View.php?view=Mods.Detail&id=172", which adds need to eat. The ingriedients are consumed automatically from Your inventory. In my opinion the eating aspect is barely noticable, and the penalties can get frustrating (Eg. You are exiting a cave with lots of loot, and suddenly get hungry and strenght will be lowered. When out of food, well, You must drop some loot).
The best approach for eating and drinking is in http://www.freewebs.com/tonto_101/ . It also adds a need for eat, drink and sleep. To eat, simply drag and drop the ingriedient on a character. I don't remember what was the penalties, but the one thing I remember that this mod wasn't finished or something, I ran in some troubles with it.
The perfect thing would be to combine "Health Suite" method of eating and penalties from "Survival", but I'm not sure if that kind of mod exist.