Before we get into the more in-depth information about how sleep and weight relate to each other, we have to define a couple of key appetite hormones affected by sleep:
- Leptin: decreases appetite; when leptin is high, you feel full
- Ghrelin: increases appetite; when ghrelin is high, you feel hungry
So when you think about not getting enough sleep and its direct relation to weight gain or lack of weight loss, what do you think happens to these two hormones when you lack sleep?
You guessed right again. Your “I-feel-full” hormone leptin decreases while your “I’m-so-hungry-I-could-eat-a-horse” hormone ghrelin increases. In plain English, when you don’t sleep enough, you’re more likely to crave food. And when you eat more food than you need, you gain weight.
That’s not all the bad news, though. There’s more to this sleep and weight conundrum.
Studies show when you’re sleep-deprived, the part of your brain responsible for rewarding yourself is more active. That means when you’re sleepy, you’re more likely to choose “rewarding” foods like carbs and sugar-laden treats.
Again, no good for the waistline.