What is fasting? It's when you abstain from doing things for a certain amount of time for the purpose of increasing your gratitude, and decrease your spoiled fleshly nature. It's a treatment for gluttony. What is gluttony? Indulging in excessive amounts of pleasure inducing activity of any kind for the mere sake of doing it and especially out of habit, and in excess. Drinking too much beer, smoking too much pot, etc.