Sleep plays a vital role in good health and well-being throughout your life.  You need to get enough quality sleep to help protect your physical and mental health, quality of life, and safety.  Yet, many people don’t realize that sleep deprivation can also affect body weight.

In a clinical study recently published in the journal Sleep Medicine, investigators studied the association between night-time sleep duration and the incidence of obesity.  The study was comprised of 1145 people who were evaluated after 11 years.  The investigators found that the incidence of obesity over the 11-year follow-up increased in subjects with fewer hours of night-time sleep.

So, what exactly is causing this effect?  And, does the opposite hold true?  In other words, if one sleeps more, can one expect to lose weight?

“It’s not so much that if you sleep, you will lose weight, but if you are sleep-deprived, meaning that you are not getting enough minutes of sleep or good quality sleep, your metabolism will not function properly,” explains Michael Breus, PhD, author of Beauty Sleep and the clinical director of the sleep division for Arrowhead Health in Glendale, Ariz.

Breus explains that our nightly hormones – “ghrelin” and “leptin” – are the key to understanding this phenomenon.  “Ghrelin is the ‘go’ hormone that tells you when to eat, and when you are sleep-deprived, you have more ghrelin,” Breus says. “Leptin is the hormone that tells you to stop eating, and when you are sleep deprived, you have less leptin.”

What’s the bottom line?  If you are sleep deprived, your body generates more ghrelin and less leptin which ultimately leads to weight gain.