Is Lack of Sleep Making You Fat?

Our culture has been buying the “calories in, calories out” theory of the weight gain and weight lose for decades. The assumption is that if you are overweight, you are eating too many Twinkies and sitting on your butt while doing it. And although what you eat and how you move your body are incredibly critical factors in your body composition, there are a multitude of others—sleep, for one.

Sleep is a vital function of the human body. We still don’t full know the full reasons for why we sleep, or understand all the very complicated biochemistry that goes along with it, but every single one of us knows that we feel great when we get a good night sleep and awful when we don’t. We don’t know everything about sleep, but we know enough to know that it matters. A lot.

But, how could not getting enough sleep make us fat? It seems counter-intuitive. Shouldn’t we lose more weight if we are awake for more hours, doing more stuff and burning more calories? Research seems to be suggesting that it’s actually the opposite.

For example, sleep-deprived people have:

  • Increased levels of ghrelin, the hunger hormones, making them feel more hunger and causing the overeating of calories.
  • Decreased levels of leptin, the “fullness” hormone, so your appetite is never sated.
  • Decrease energy levels which results in decreased exercise, therefore decreased metabolism.
  • Changes in the effectiveness of insulin in the body causing increased cravings for carbs.

In effect, then, sleep deprivation makes us eat more, crappier food, while doing less of just about anything else besides sitting on furniture.

How much is enough sleep? About 7-8 for guys, 8-9 for girls on average, but everyone is different. The right amount of sleep for you equals the amount that’s necessary to wake up naturally, without the help of an alarm, where you feel rested and refreshed.

Is lack of sleep making you fat? Not exclusively. But it’s probably a far greater influence on your ability to lead a healthy lifestyle than you might realize. So while you can’t just sleep your way to great health, perhaps your next “diet” ought to include getting enough rest, too.