How can lack of sleep affect my appetite?

If you don't get enough sleep to keep your body's engine humming, you'll start to throw your appetite hormones out of whack. Sleep is not a luxury.

The two digestive hormones that control your feelings of hunger and appetite are ghrelin and leptin. As with many hormones, these two are paired together but have opposing functions. One says "Go" and the other says "Stop." Ghrelin (your "Go" hormone) gets secreted by the stomach when it's empty and increases your appetite. It sends a message to your brain that you need to eat. When your stomach is full, fat cells usher out leptin (your "Stop" hormone) so your brain gets the message that you are full and need to stop eating. A bad night's sleep -- or just not enough sleep -- creates an imbalance of both ghrelin and leptin.

Studies now prove that when people are allowed just four hours of sleep a night for two nights, they experience a 20 percent drop in leptin and an increase in ghrelin. They also have a marked increase (about 24 percent) in hunger and appetite. And what do they gravitate toward? Calorie-dense, high-carbohydrate foods like sweets, salty snacks, and starchy foods. Sleep loss essentially disconnects your brain from your stomach, leading to mindless eating. It deceives your body into believing it's hungry (when it's not), and it also tricks you into craving foods that can sabotage a healthy diet.