If you mean food and water, here is some guidelines based upon stuff I had from another system I once worked on
In a moderate climate, a character will require the equivalent of approximately 1 gallon of water and 1 pound of food per day. These measures constitute one "ration" of each.
If the character does not meet those requirements, he will deteriorate and eventually die. Characters in an extremely hot climate will require an extra ration of water each day, while those in an extremely cold climate require an extra ration of food.
Starvation
A character can survive for about a month without food. For each daily ration that is missed, the character will receive a -1 modifier. When the character reaches -20 he will no longer be able to feed himself, and when he reaches -30, he will die.
Thirst
Dying of thirst is faster than dying of starvation. Each day without a ration of water will result in the character receiving a -3 modifier. As with Starvation, at -20, he will be helpless and when he reaches -30, he will die.
Half-rations
If a character is able to consume at least half of a normal ration, he will not deteriorate any further, but he will not get better either.
Recovery
The only way to remove the modifiers from starvation and thirst is by eating and drinking. Healing magic will not work. Each day that the character consumes a normal ration of food and water will reduce the modifier by the same amount that it would have increased without the ration.
Does this work?
