You’ve probably heard here and there that getting enough sleep is extremely important if you’re trying to lose or maintain your weight. I first learned about this subject from Dr. Oz, who talked about the connection between sleep deprivation and the hormone cortisol. In fact, I think that was what sparked what you now probably recognize as my slight crush.

It’s important to know the several ways that a lack of sleep can stop you from losing weight and even make you gain even more weight.

Huffington Post just uploaded an excellent video interview between Marlo Thomas and celebrity fitness trainer Terri walsh, that does a very good job of explaining some of how this works.

As she explains, your body builds muscle while you sleep. Muscle repair (and all cell renewal) is done while you’re sleeping. You may work out in the gym, but your body repairs those muscles while you’re asleep, which is what build lean muscle. If you don’t get enough sleep, your body can’t do its job and that workout goes to waste.

But there’s more to it than that.

A lack of regular and sufficient sleep also interferes with your body’s hormone regulations; specifically three hormones that have an awful lot to do with your weight:

1. Cortisol…..Cortisol is a stress hormone that stimulates your body to store fat rather than burn it. When you don’t get enough sleep, your body assumes that you’re under duress and food may be in short supply in the near future. (Which it often is if you’re stressed out and have lost your appetite.) So, when you don’t sleep, more fat is stored around your abdomen than there normally would be.

2. Leptin….leptin is the hormone that tells your body that you’re full. When you don’t get enough sleep, leptin levels go down. So, it takes you longer to feel full. In the meantime, you’re shoving in way more food at a meal than you ordinarily would. Where do those extra calories go? Your jeans, mostly.

3. Ghrelin…ghrelin is the sister hormone to leptin. It tells you when you’re hungry. When you don’t sleep enough, your body fights fatigue by releasing more ghrelin. This is why, when you’re tired and overworked, you find yourself grabbing extra snacks and high-calorie, high-carb foods. And guess what? You’re still low on leptin so you’ll eat two candy bars instead of just one. Awesomeness!

So what do you do?

Get a minimum of six hours sleep, but seven or eight is better. You also want to sleep at roughly the same time every night, within an hour or two.

That’s a lot easier than working out even harder and longer, isn’t it?