Fasting per say does nothing to the body. What a fast does is enable the human body to engage in "house-cleaning" in order to restore normality (to the best of the body's abilities). Viz the Medical Journals there are over 500 studies on fasting, though much more research is needed. Dr Fuhrman mentions several of these on his website DrFuhrman.com and in his book. If you undertake a fast for any period of time, I would talk to a doctor who is TRAINED in fasting, like Dr. Fuhrman, who has supervised 1000's of fasts. A physician who is not trained in fasting can be harmful since he is unable to differentiate between symptoms of a fast and symptoms of disease. An uneducated layman is even worse. If you are looking for a step by stop program, then you will need Dr. Fuhrman's upcoming book, as the present book primarily focuses on principles, and the spectacular results achievable in reversing diseases such as uterine fibroids, lupus, arthritis, heart disease, diabetes (type II), and many, many others. If you are skeptical I suggest you read this book and judge for yourself. You owe yourself that much. Let me end with a quote from Dr. Fuhrman's book: After hearing about a natural food diet and therapeutic fasting, individuals may enthusiastically give it a try and get well. It is also possible that they may become excited about the sensibility of this approach and the prospect of finally recovering their health, but then go home to their friends and family and become discouraged after being told that they would be crazy for attempting such an "outrageous" treatment. They might have even called a few doctors they know only to be told that fasting is risky, dangerous and stupid. It continually amazes me how "expert" opinions can be given on something with which someone has had no experience, knows nothing about, and has never read research on. I once had an occasion to speak to one such well meaning physician who was furiously against fasting. I told him I had read, and was thoroughly familiar with over 500 medical journal articles on therapeutic fasting, that I had spent years collecting. I inquired as to which ones he was familiar with, which helped him reach his opinion. His answer was that he had not read one of them. He actually had zero knowledge about the subject and began to ask me questions. He was consumed with the same vague fears and questions the typical layman would have. Though still having doubts, after our conversation he admitted he gave his opinion too hastily, and had much more to learn.