 Okay, everybody, Dr. O. In this video, we're going to cover how a lack of sleep hurts your metabolism, right? We've already seen we eat too many calories because poor sleep makes us hungry and also leads to poor food choices. But that's only half the problem. We also burn fewer calories and have a slower metabolism if we're not getting enough sleep. Eating more and burning less is a recipe for disaster. Let's find out how. All right, first study. What does the science say? The hypothalamic, pituitary, thyroid axis, and sleep. Lots of big words. Don't worry about it, but the key there is the thyroid, right? Your thyroid gland produces thyroid hormone, which regulates your metabolism. Well, here's the problem. A single night of short sleep decreases thyroid hormone function by 30 percent. So if your thyroid hormone levels determine your metabolism, you certainly don't want a decreased production or function of thyroid hormone by 30 percent. All right, next study. Resting metabolic rate varies by race and by sleep duration. So in this study, there were 47 participants. They had them sleep four hours per night for five days. Their resting metabolic rates decreased by 2.6 percent. Again, may not seem like a huge number, but if your metabolic rate was 2,000 calories per day, a 2.6 percent drop would be 52 calories per day that you're no longer burning. That would be 18,980 calories per year. That's almost five and a half pounds of fat. Next study. Eating breakfast and avoiding late evening snacking sustains lipid oxidation, which means burning fat. So poor sleep also often leads to eating more at night, but you can't burn fat off of your belly if you're burning a stomach full of food first. So people that eat late at night, they actually burn 15 fewer grams of fat per day. That's 5,475 grams per year. That's over 12 pounds of fat. So the problem is if you're not burning fat, what are you burning? And as we'll see, as we'll see soon, we're burning more lean mass. We're burning more muscle. So are you starting to see how all of these little things are adding up to a huge problem? Another one. Poor sleep makes you less physically active, right? If you're not sleeping while you're going to be tired, and that's going to make you less motivated to exercise and more likely to sit around and be sedentary. So your poor sleep habits made you gain fat by eating more and moving less. But wait, once again, it gets worse because it's also going to make it much harder for you to lose fat by holding onto it while burning muscle for fuel instead. This is why I call poor sleep anti-exercise. And I'll cover this in the next video. Have a wonderful day. Be blessed.