Proponents of fasting and cleansing believe that by giving the body a "break" from the daily chores of digesting foodstuffs, you give the body an opportunity to spend its energy to repair, detoxify, or rejuvenate itself. Certain exercises and herbs have also been traditionally used to encourage detoxification.

There are many approaches to fasting and cleansing, including liquids-only diets; organ-specific cleansing techniques; ingestion of fibrous or purging natural substances to "sweep" out the digestive tract; flushing tracts with water, as with colon hydrotherapy or enemas; and exercises which help stimulate natural detoxification of the organs, as in yogic Kriya techniques.