America's Growing Sleep Crisis, Part 2

America isn't getting enough sleep, and it's killing us. In another recent article I elaborated the point that we simply aren't sleeping enough, so if you haven't read it, you might want to start there. Now I'd like to outline some of the reasons you probably want to avoid consistent lack of sleep. Trust me, there are plenty.

Sleep deficiency makes you fat

Surprised? So was I. Researchers at the University of Chicago wanted to test this apparent correlation, so they took 12 young men and limited them to just four hours of sleep for two consecutive nights. They found that after only two sleep-deprived nights, the hormone leptin was substantially decreased, while the hormone ghrelin was substantially increased. Leptin is the substance that basically tells the brain that the body's full, and ghrelin is the one that tells the body to eat everything in sight. So in just two short nights, your appetite turns from a well-regulated, sensible process to an out of control eating machine. Another study in October 2005 surveyed nearly 10,000 adults: Those who slept less than 7 hours per night were more likely to be obese than those who slept 7 hours or more. There's a clear correlation here: if you don't get enough sleep, you could get very, very fat.

Sleep deficiency makes you stupid