According to a new study presented at the 2012 AHA Scientific Sessions in San Diego, people who don’t get enough sleep may eat over 500 extra calories per day. Over the course of a week, that adds up to almost 4,000 extra calories, which could make sleeplessness a cause of weight gain.
The study tracked the habits of 17 healthy young adults over the course of eight days. During the first three days, researchers documented participants’ normal eating and sleeping routines. During the last five days, half of the participants were allowed to only get two-thirds of their usual amount of shuteye. This lead to an increase in food intake across the board. Study co-author Dr. Andrew Calvin was surprised by his team’s dramatic findings.
“A lot of people assume if they are awake longer, they will move more and burn more calories,” Dr. Calvin explains. “We thought sleep deprivation would reduce leptin (the hormone that tells your brain to stop eating) and increase ghrelin (the hormone that signals to your brain that you are full).”
However, lack of sleep had the opposite effect, increasing leptin and decreasing ghrelin. Lead author Dr. Virand Summers elaborates, “From a physiologic perspective, we know that sleep is a very important time for the release of many physiologic hormones. It’s a time when the body repairs itself, the brain consolidates memories, and growth hormone is released. All of these important functions are impacted by less sleep time.”
University of Chicago’s Dr. Eve Van Cauter was not shocked by the appetite-enhancing phenomenon. “The increase in leptin is due to the weight they gained during the week. When you eat 549 extra calories a day for eight days, there is no way their weight would have been stable. When you put on more weight, that additional weight comes in the form of fat. Leptin levels are proportionate to fat.”
To conclude, don’t take sleeplessness lightly! Although setting aside serious time for slumber can be difficult, the implications for your well-being (and waistline) are large.
Having trouble sleeping? Check in with one of our sleep medicine specialists.
Image: Insomnia, a Creative Commons Attribution (2.0) image from Alyssa L. Miller’s photostream.