How do you lose belly fat quickly?
Cohen explains that staying up late throws off biorhythms, causing a person to eat more. Specifically, tiredness makes the body produce more ghrelin, which triggers cravings for sugary and other fattening foods. Losing sleep also tampers with hormone production, changing cortisol levels that can cause insulin sensitivity, which is a prime cause of the development of belly fat.
Sources: forbes.com, mensfitness.com