Each character has a food pool and a water pool. Both drain continuously. Each pool has three bands. In the top band there is no effect. In the middle band the character is hungry or thirsty and suffers no penalty. In the bottom band the character is starving or dehydrated and loses vigour. Needs never reduce hit points.
Eating and drinking
Eating is an action that takes a few seconds and can be interrupted. The amount a food restores is a property of the food. Cooked food restores more than raw food.