Diets to a great extent fail because, while facilitating weight loss initially, the dieter usually returns to poor eating habits once the regimen is over. This, of course, is not a generalization. There are many excellent diet programs that work at changing a persons behaviors as it relates to food. But, in most cases, good people find themselves trying every diet under the sun - yet the obesity and overeating problem resurfaces time and again. Fasting for weight loss incites a process of deep detoxification. It gives the body an invaluable opportunity to stop focusing most of its resources on digestion, allowing it instead to shift its attention to cleansing and tissue repair. Many have thus been healed of terminal illnesses.
I have experienced this in a small way myself. Before I started fasting, I had chronic acne. It was always there and I never had a day where there were not at least 3 pimples on my face. Since I have been fasting, I have had clear skin. I get an occasional pimple from time to time, but it doesn't bring friends and heals fast. I used to also get blemishes on my shoulders and back. Those have COMPLETELY cleared up and I haven't had one blemish on that area since January. That is a very SIGNIFICANT change that I have seen happen ONLY since incorporating fasting into my life.