Lack of sleep can eliminate the hormone that regulates appetite. As a result, the desire to eat high-fat and carbohydrates will increase.

What I mean here are two kinds of hormones in our bodies, namely leptin and ghrelin, both of which affect our appetite. Michael Breus, PhD, a faculty member of the Atlanta School of Sleep Medicine and director of The Sleep Disorders Centers of Southeastern Lung Care in Atlanta explained that Leptin and ghrelin work in a kind of "checks and balances" system to control our feelings of hunger and satiety.

Scientists have uncovered an inverse relationship between the hours of sleep and blood plasma concentrations of ghrelin; as the hours of sleep increase, ghrelin concentrations were considerably lower, thereby potentially reducing appetite and avoiding potential obesity.

Not enough sleep for 2 nights can trigger excessive hunger. This condition occurs because the hormone ghrelin stimulates appetite enhancer and reduces leptin as an appetite suppressant. When leptin levels down, you will not feel satisfied after you eat. Even you will feel you need more food because of the hormone ghrelin increases.

What Is The Minimum Sleep Required By A Person?
Although this can vary from one person to another, ideally you should get a minimum of 7.5 hours of sleep every night, while getting 8 or even 9 hours continuous sleep is much preferable.

But in reality most of us sleep less as we get older. Perhaps this is one of the factors that led many elderly people become overweight easily.