Food

Food is used in Minecraft to restore health. Some types of food (eggs, milk, sugar, wheat, and mushrooms) are used as ingredients to make food that can be consumed, but cannot be eaten on their own. Food is eaten by right-clicking, in the same manner as blocks and items are placed or used. Cake must be placed before it can be eaten, but after that is consumed by right-clicking it.

Food ingredients with the exception of Milk are stackable items, whereas food items with the exception of Cookies are not stackable.

Notch has suggested a food bar of some sort, which could mean that you will need to eat periodically, whether or not you've taken damage.

Ingredients
Eggs, milk, mushrooms, wheat, cocoa beans, and sugar cannot heal unless they are crafted to make some of the food items above.