The book "The Tao of Health, Sex, and Longevity" teaches a person how to detox through fasting. The author recommends a 7 day fast, 3 day fast, or a mini fast. I have only done the mini fast which consists of choosing one fruit and sticking with it for 3 full days. Red grapes are the best to detox your system. The book is an extremely useful tool so you understand how your body works and what is happening to your body during the fasting process. I usually lose around 5 to 6 pounds after a fast. (My normal weight fluctuates from 114 to 118). My friend has done the 7 day fast. After about the fourth day she says the hungry feeling goes away. I highly recommend the book before starting. Hope this helps. Good luck!