If the weekend is the perfect time to fall asleep, you may want to rethink your strategy.
In young adults, compensating for the lack of sleep during the weekend by a weekend can lead to an increase in snack foods late at night, weight gain and reduced reactivity to insulin, according to researchers Current biology.
"The message to remember is essentially that you can not compensate for the abuse of your sleep by sleeping a few more hours on the weekend," said Paul Shaw, neuroscientist at Washington University in St. Louis. study. "It's not as simple as saying," Oh, if I sleep on the weekend, I'll be better. "
Since the 1990s, scientists have understood that lack of sleep can affect a person's metabolic health and lead to behavioral and physiological changes that can lead to obesity and type 2 diabetes. 35% of US adults reported sleeping less than the recommended seven hours a night, according to the latest available data from the US Centers for Disease Control and Prevention.
Weekends may seem like the perfect time to catch up, but we did not know if it would work. Christopher Depner, a sleep physiologist at the University of Colorado at Boulder, and his colleagues therefore submitted three groups of young adults aged about 20 to different sleep regimens for about two weeks. One group slept for about eight hours each night; another has about five hours a night; the third have about five in the evening on weekdays and sleep as they wish throughout their weekend.
Recovery weekend sleepers generally slept until midnight or 1 am on Friday and Saturday nights, and slept between 11 am and noon. But they also stayed up late on Sunday, sleeping about six hours before the work week. Cumulatively over the weekend, each only has about 1.1 hours more than the suggested natural sleep cycles between Friday and Sunday, according to the researchers.
"So they slept well," says Depner, but not enough to recover the lost sleep during the work week.
And, like the group that slept too little every night, the sleepers of the weekend earned something: the weight. Lack of sleep disrupts appetite control hormones such as leptin, says Depner. And the fact that the natural biological clocks of the sleepers of the weekend spent later hours made them feel hungry later. During the work weeks, both groups consumed about 400 to 650 calories in late-night snacks, such as pretzels, yogurt and potato chips. At the end of the experiment, people in both groups had gained on average about 1.5 kg.
But with respect to insulin sensitivity, the two groups diverged. The sensitivity of all body tissues in the weekend recovery group dropped by about 27%, compared with the baseline sensitivity measured early in the experiment. This was significantly worse than the 13% drop among those who were still sleeping little. And the weekend sleepers were the only ones to experience a significant decline in liver and muscle cells – two important factors for the digestion of food – after a weekend of trying to catch up on sleep.
"It was very unexpected," says Depner. Cycling between sleepless weeks and recovery weekends could "have negative health consequences per se".
Peter Liu, a sleep endocrinologist at UCLA, wonders if these findings are widely applicable, especially in people with chronic sleep deprivation. He found that a few extra hours of sleep were beneficial for insulin sensitivity in his studies of people who themselves said they were not getting enough sleep. "This is not the last word on this important subject," he says.
But resting is "the third pillar of a healthy lifestyle: sleep, exercise and diet," says Liu. "Just as you would not say to someone:" You must be well fed Monday to Friday, but on weekends you can eat whatever you want, "I think it's the same principle here with sleep. "