I have done a 22 day fast. Does it matter how much weight I lost? Do you think someone can go that long and not lose any weight? Does it matter that I was thin when I started it? How much you lose can vary greatly depending on how much salt you have that is causing water weight and other things. This site called Lemonade Diet has everything you want to know about losing weight fasting. It has quotes from 18 different MDs and even the New England Journal of Medicine telling about fasting to lose weight. The home page has a section about water weight.