There are actually a couple reasons why losing sleep makes you hungrier. When your body has to extend its normal waking hours beyond the routine, you end up with a hormonal imbalance that has various effects on how you feel.

When you’re going about your daily routine, your body produces a hormone called ghrelin when it wants to let you know you’re hungry and it’s time to eat. When you’ve had enough, another hormone, leptin, lets you know that by helping you feel full.

If you aren’t sleeping, your body starts making more ghrelin and less leptin, meaning you feel hungry when you really aren’t and you don’t feel as full as you should either. That’s a surefire recipe for overeating.