How Sleep Affects What -- and How Much -- you eat | Sleeping with Science

An imbalance in two key appetite-regulating hormones called leptin and ghrelin could be a major cause of unwanted weight gain.

Leptin sends a signal of fullness to your brain, so that you feel satiated from eating food.

Grhelin sends a signal of hunger to your brain.

Levels of leptin decrease and levels of ghrelin increase when you don’t get sufficient sleep, so you’ll constantly feel hungry.