Humans need approximately one pound of food every 24 hours. If sufficient sustenance isn't available, a character begins to suffer from severe hunger.

Starting the first day after the meal was missed, the character must make a Vigor roll. Subtract 2 if the hero has less than half the required amount of food. Failure means the character gains a Fatigue level.

After the first day, the character must roll for hunger every 12 hours, and thirst every 6 hours.

The Survival Skill: A successful Survival roll each day provides enough food and water for one person, or enough for five with a raise.

• Recovery: At least a pound of decent food allows a character to recover a Fatigue level every hour, or every 12 hours if he reached Incapacitated.
• Incapacitation Effects: A character Incapacitated by hunger dies 3d6 hours later.

Savage Worlds Deluxe Edition p. 102