There are several explanations for why sleep problems causes weight gain.  Two key players are the hormones leptin and ghrelin.  Leptin suppresses appetite while ghrelin does just the opposite – it stimulates it. In just a few weeks of not sleeping well, your leptin levels can decrease by as much as 15%. Instead of registering that you are no longer hungry, your brain receives the message, ‘Hey! I am hungry. I need to eat.’  Uh oh! A few y