This book (and Dr Fung's subsequent articles on intermittent fasting) has been an absolute revelation for me. I too have been totally focused on calories in, calories out and never fully understood the effect different foods and food timing has had on my weight. An absolute must read for anyone looking at weight control or working with clients who are looking for weight loss. Intermittent fasting has been an amazing eating manipulation method for me personally. I have lost more weight in the past 6-months using this method than in the last 6-years of training in the gym 5-days per week.