"Catching up" on lost sleep may actually do more harm than good

Sleeping late on weekends not only won't help much when it comes to your sleep debt from the week, it can also lead to weight gain, insulin sensitivity, and nighttime hunger. University of Colorado Boulder sleep physiologist Christopher Depner ran a study involving young adults who were assigned different sleep regimens over a two week period, including a group of "weekend recovery sleepers." They report their results in the scientific journal Current Biology. From Science News:

Lack of sleep disrupts appetite-controlling hormones such as leptin, Depner says. And shifts in the weekend sleepers' natural biological clocks to later hours caused them to get hungry later. During the workweeks, both groups consumed roughly 400 to 650 Calories in late-night snacks, such as pretzels, yogurt and potato chips. By the end of the experiment, people in both groups had gained on average around 1.5 kilograms.

But when it came to insulin sensitivity, the two groups diverged. Sensitivity across all body tissues in the weekend recovery group dropped around 27 percent, compared with their baseline sensitivity measured at the start of the experiment. That was substantially worse than the 13 percent decline in those who consistently had little sleep. And the weekend sleepers were the only ones to have significant declines in liver and muscle cells - both important for food digestion - after a weekend of trying to catch up on sleep....

Peter Liu, a sleep endocrinologist at UCLA, questions whether these results are broadly applicable, especially in people who are chronically sleep deprived. He's found that a few extra hours' sleep was beneficial for insulin sensitivity in his studies of people who self-reported not getting enough sleep.

image: "Le Sommeil (Sleep)," by Salvador Dali, 1937