A character needs one pound of food per day and can make food last longer by subsisting on half rations.

Eating half a pound of food in a day counts as half a day without food.

A character can go without food for a number of days equal to 3 + his or her Constitution modifier (minimum 1). At the end of each day beyond that limit, a character automatically suffers one level of exhaustion.

A normal day of eating resets the count of days without food to zero.