Why health is harmed by sleeping in on weekends

Catching up on sleep by sleeping in on weekends is a common practice amongst many Americans. Who doesn’t want to rest up by lying in bed extra hours when you don’t have to get up for anything?

While it sounds ideal to sleep in as late as possible on days off from work, a new study finds that this habit is no friend to your waistline or health. This research, published in the journal Current Biology, shows that sleeping in on the weekends does not fix the body’s inability to regulate blood sugar if the weekend is followed by a workweek or school week full of insufficient sleep.

The American Academy of Sleep Medicine recommends at least seven hours of sleep each night for adults and more for children.

Sleep study

For the study, 36 healthy young men and women were assigned to three groups that had different sleep requirements over a total of 10 days. Participants chosen did not have any current health issues, young babies in their homes or other factors that might affect the quality of their sleep.

The first group was assigned to sleep for nine hours a night for the 10 days; the second group was restricted to sleeping only five hours a night during this same timeframe; and the third group was restricted to five hours of sleep Monday through Friday but were allowed to sleep as long as they wanted on the weekend and to go to bed as early as they liked on Sunday night. Come Monday, the third group was put back on the deprived sleep schedule of only five hours a night.

Results

What was found from this study was that even if a person sleeps in on the weekends, if they continue to sleep poorly throughout the week, they will end up eating too much resulting in weight gain.

The groups that were sleep-deprived were shown to snack more after dinner, thus gaining weight, affecting men much more than women. Men who were sleep-deprived showed a 2.8% increase in their weight while women’s weight increased by only 1.1%. Men who slept in on weekends showed a 3% increase in weight gain while the women only showed a small 0.05% increase in weight.

Sleep deprivation leading to weight gain is nothing new and has been known for a long time. Studies in the past have shown that people, who are not getting sufficient sleep, tend to eat more partly because their body is burning more calories. But these individuals often eat more than they need which leads to weight gain. It is believed that this cycle is a result of hunger hormones affected by chronic lack of sleep.

There are two hunger hormones, leptin and ghrelin. Leptin is a hormone that helps reduce appetite, while ghrelin is a hormone that does just the opposite – it increases appetite. When a person is sleep deprived, this causes a decrease in leptin and an increase in ghrelin, resulting in feeling hungrier.

This study was important in that it showed that even though a person may sleep in on weekends to “catch up” on sleep they miss out on during the week, it was still insufficient. Once they go back to work on Monday to a shorter sleep schedule, their body’s ability to regulate blood sugar was impaired. The weekend recovery group was shown to have increased sensitivity to insulin in both their muscles and liver, a result not found in the second group on restricted sleep. The muscles and liver are two of the most important tissues in the body that take up extra blood sugar after eating.

For those who are not getting sufficient sleep, this can be one reason why they may be at an increased risk for developing diabetes. When they are consistently getting short, insufficient sleep throughout the week, this leads to an inability to regulate blood sugar and increases the risk of metabolic syndrome long term. Metabolic syndrome is diagnosed when a person has excess abdominal weight, high blood pressure, high blood sugar and increased lipid levels all at the same time, increasing a person’s risk of heart disease, stroke, and diabetes.

Other findings from this study show that when circadian rhythm or our biological clock has been altered from sleep deprivation, it tends to shift due to sleeping in later on certain days of the week but not on other days of the week. When a person tries to get caught up on sleep on the weekends, they tend to eat later by adding in snacks after dinner, eating more calories than usual.

The takeaway from this study is to get more sleep during the week days and to avoid sleeping in on weekends. Have a set bedtime routine Sunday through Saturday, of going to bed earlier to obtain more sufficient sleep to prevent the need to sleep in on weekends. And it is also recommended to not sleep in on weekends to begin with.