Complete or partial fasting is recommended at least once each lunar cycle. It helps to detox the organism, purify the blood as the Elders called it, regaining youth, becoming more alert, in better shape.
Fasting from one dawn to another during waxing moon. Drink lots of water. The day after, don't eat anything else than fruit and honey.
The virtues of fasting are famous. The organism will draw from its reserves ridding some of what weighs it down otherwise. The fasting can last from one to a few days, a medical advice could be a good idea before starting.