Fit for Life the Natural Body Cycle, Permanent Weight-loss Plan That Proves It's Not What You Eat, but When and HowFit for Life (FFL) is a diet and lifestyle stemming from the principles of natural hygiene, an offshoot of naturopathic medicine. It is promoted mainly by the American writers Harvey and Marilyn Diamond.[1] As the title of the 1985 book suggests, Fit for Life claims that one can lose excess body weight and maintain good health via long term dietary and lifestyle practices, rather than short term dieting. In the Fit for Life book series many dietary