Sleep deprivation is a terrible thing: It messes with your brain, making you less alert and less able to think clearly. In previous articles on this site, we’ve talked about how not getting about six hours of sleep per night for long periods of time also increases your chances of being overweight. But according to new research, even a few nights of insufficient sleep can cause almost immediate weight gain.
Kenneth Wright, and his team at the University of Colorado Sleep and Chronobiology Lab had 16 men and women go through a rigorous two-week sleep study. And by “rigorous,” I mean wow! The researchers carefully monitored participants’ metabolism 24/7, recording every meal and snack, and going to far as to track oxygen intake and carbon dioxide production. They also imposed some pretty strict sleep schedules.
For the first week, half the group was allowed to sleep 9 hours per night, while the other half was limited to 5 hours. In the second week, the groups switched.
Now here’s the interesting thing. The sleep deprived participants’ metabolism kicked into high gear, burning more than 100 extra calories per day than usual, which makes sense. “Sleep loss itself leads people to expend more energy because the body needs more to keep it awake,” said Wright.
Sounds like sleep deprivation could be the next diet craze, doesn’t it? Sorry—it doesn’t work that way. The sleep-deprived participants actually ate more calories than they expended—especially fats and carbs—subconsciously trying to give their body the extra energy it needed to overcome exhaustion. According to Wright, “People eat more in response to these needs, but they eat more than they really need to, which leads to weight gain.” A lot of those extra calories came in the form of after-dinner snacks.
Another study, done late last year, found that sleep deprivation also interferes with our fat cells’ ability to function–something that could lead to weight gain, increased diabetes risk, and a number of other health problems. “Many people think of fat as a problem, but it serves a vital function,” said Matthew Brady, PhD, associate professor of medicine and vice-chair of the Committee on Molecular Metabolism and Nutrition at the University of Chicago.”Body fat… stores and releases energy. In storage mode, fat cells remove fatty acids and lipids from the circulation where they can damage other tissues. When fat cells cannot respond effectively to insulin, these lipids leach out into the circulation, leading to serious complications.” Brady added that fat cells need sleep to function properly.
In Brady’s study, In Brady’s study, participants were allowed to sleep either 8.5 hours or 4.5 hours per night for four consecutive nights, carefully measuring insulin levels and fat-cell functioning before and after each phase of the experiment. After four nights of not-enough sleep, the participants’ insulin response decreased by an average of 16 percent, and the insulin sensitivity of their fat cells decreased by 30 percent. According to Brady and co-author Esra Tasali, also from the University of Chicago, these reductions are comparable to the difference between cells from obese vs. lean participants or from people with diabetes versus non-diabetic controls.
Wright’s results were published in the Proceedings of the National Academy of Sciences. Read an abstract here. Brady’s study was published in the October 16, 2012 issue of the Annals of Internal Medicine. Read an excerpt here.