With the new year just around the corner, I can already hear alarm clocks across the country being set earlier as those who aspire to lose weight push themselves out of bed to exercise. But according to an ever-growing body of research, when it comes to weight loss, the best thing we can do might be hitting the snooze button. “What the data shows is when people don’t sleep enough, certain hormones get affected and people will put on weight,” says Dr. Meir Kryger, a professor at the Yale School of Medicine and author of The Mystery of Sleep: Why a Good Night’s Rest Is Vital to a Better, Healthier Life.
Kryger expands on this and shares other counterintuitive ways in which sleeping more allows us to accomplish more.
It helps us lose weight.
One large analysis of 68,183 women in the Nurses’ Health Study found that women who slept five hours or less per night weighed an average of 4.71 pounds more than those who got seven hours or more sleep a night. This was regardless of their diets and exercise. Similar results have been found in studies of men and children. When we don’t get enough sleep, Kryger says, it increases the levels of a hormone called “ghrelin, which is a hormone that makes you eat more.” At the same time, lack of sleep decreases levels of the hormone leptin, which normally stops you from eating. As a result, Kryger says, “People who are sleep-deprived tend to put on weight.”
It increases our athletic performance levels.
If instead of exercising, we stay in bed a little longer, we’ll likely do better when we finally get to the gym. “There have been studies that have looked at how well athletes do under certain conditions. Basketball players, for example, seem to play better when they’ve had a normal amount of sleep,” Kryger says. “Many world-class athletes sleep way more than people think. Many sleep more than 10 hours.”
Basketball great LeBron James considers sleep part of his preparation and reportedly shoots for 10 hours of sleep a night, and naps to make up for lost time. Kryger says this is common, as most professional athletes understand the importance of adequate sleep, though the public hasn’t yet figured that out.
It makes us smarter.
In one study of sleep and cognition, participants were told to solve a difficult math problem, but were not taught a simple method for quickly solving it. Participants were divided into two groups to be retested eight hours later on the problem; one group pulled an all-nighter studying for it, while the other group was allowed to sleep. The group that was well rested was twice as likely to find the quicker solution. It’s a lesson Kryger tries to impart to students at Yale. “I emphasize that an all-nighter has no place in their lives,” he says. “Staying up all night is not going to result in them doing any better on the test.” In fact, he adds, “their performance likely is going to decrease.” He advises against even staying up late to study extra, and says it’s best to just get a good night’s sleep.
It boosts our immune system and makes us healthier.
Lack of sleep also wreaks long-term havoc on our bodies. Chronic under-sleepers put themselves at an increased risk for a variety of ailments, including type 2 diabetes, cardiovascular disease, and certain types of cancer. In the short term, adequate sleep improves our immune system, possibly by providing a boost to our T cells. “Our immunity to diseases or how we respond to vaccination can be negatively affected if we’re sleep-deprived,” Kryger says. “If someone is planning to have a flu vaccine or any other vaccine, it is better if they have slept well the night before they get the vaccination.”
Sleep and menopause
One segment of the population that frequently encounters trouble sleeping is women who are perimenopausal and postmenopausal. The hormone changes women undergo lead to hot flashes. “These hot flashes can really interfere with a woman’s sleep,” Kryger says, as they often have symptoms of “just feeling hot and not being able to regulate temperature normally.”
He says it is an issue each woman “needs to talk with her gynecologist about. There are medications that can be used, but the medications need to be taken in the context of what risk will the woman have with respect to the development of other problems with these medications.”
In addition, women going through menopause are likely to put on weight, which can put them at increased risk for sleep apnea. “If they snore and all of a sudden start to become very sleepy during the daytime, or develop insomnia, they may be at risk of having sleep apnea,” Kryger says. “They should consider talking to their doctor about it because they may need to be referred for a sleep evaluation.”