Sleep is a very important part of healthy lifestyle. We spend 1/3 of our lifetime sleeping. All adults should sleep 8-9 hours a day. Professor Moss from Cornell University spent most of his professional carrier on research in field of sleep and its influence on human organism. He summarized his work in a well-known book called “Power of Sleep” . Homo sapiens function during the day and sleeps at night. Often reversal of circadian rhythm is a necessity (for example night shift work) which may be the source of many physiological problems, somatic and psychological diseases. Improvement of quality of sleep and optimal amount of sleep is imperative in a medical weight loss program. Sleep patterns, sleep positions and sleep environment (bedroom settings) are discussed and corrected as needed on individual basis.