When you have had a lack of sleep, you quite often crave sugary foods that give you a fast energy booster. Lack of sleep can directly link to weight gain and eating too much.
The more sleep you lose, the more food your body craves.
The two hormones that regulate feelings of fullness and hunger are: Ghrelin which stimulates appetite, and leptin which signals the brain once you're full. When you are sleep deprived, your ghrelin levels increase, stimulating your appetite so more food is needed, and your leptin levels decrease, so you are not feeling satisfied and don't want to stop eating.