"On average, we need about 7.5 hours of quality sleep per night, he says. “If you are getting this already, another half hour will not help you lose 10 pounds, but if you are a five-hour sleeper and start to sleep for seven hours a night, you will start dropping weight.”
Exactly how lack of sleep affects our ability to lose weight has a lot to do with our nightly hormones, explains Breus.
The two hormones that are key in this process are ghrelin and leptin. “Ghrelin is the ‘go’ hormone that tells you when to eat, and when you are sleep-deprived, you have more ghrelin,” Breus says. “Leptin is the hormone that tells you to stop eating, and when you are sleep deprived, you have less leptin.”
More ghrelin plus less leptin equals weight gain."