there's a difference between fasting and the biological process of autonlysis (sure hope I'm spelling thay at least close to right) Over the past two years, I've eaten one meal a day about 75% of the time on days that I do eat and NEVER three i.e. a salad for lunch and then dinner. Lightening up your food intake is paramount, and altogether natural compared to what we've been taught is "right". HOWEVER, when fasting, I'm looking to "burn the rubbish" in my body, and that can ONLY happen when the body shuts off the energy to the digestive tract and enters autolysis, whch is "the destruction of cells or tissues by their own enzymes." I am hypersensitive, and maybe it's just me, but I can feel this, and it is usually somewhere around three days out depending on how I've been eating prior to the fast, and certainly more profound when on water alone. It feels great. Although I really dig a lot of books on the subject, Gabriel Cousens section on fasting in "Concious Eating" is amazing, and I recommend it highly.