A new study now finds that sleeping in on weekends may not be such a good idea for a person's waistline or health.

According to experts, even if one sleeps longer on weekends, if they continue to sleep poorly, they will still eat too much, and they will still gain weight, reported CNN. Speaking about it, study author Kenneth Wright Jr, said that the common behaviour of "sleeping in on the weekends doesn't correct the body's inability to regulate blood sugar if that weekend is followed by a workweek or school week full of insufficient sleep," adding, "And when we go back to getting too little sleep again."

"We're doing things that could be negative for our health long-term," Wright added. The study, published Thursday in the journal Current Biology, assigned volunteers to three groups that had different sleep requirements over a total of 10 days. None of the participants had newborns in the home or any health impairments that would affect the quality of their sleep.

The first group had the opportunity to sleep for nine hours each night for the 10 days. The second group was restricted to only five hours of sleep a night for the same duration, while the third was restricted to five hours Monday through Friday but allowed to sleep as long as they wanted on the weekend and go to bed as early as they liked on March 4 night.

Both of the sleep-deprived groups snacked more after dinner and gained weight during the study, men much more than women. The sleep-deprived men showed a 2.8 per cent increase in their weight, while women's body size went up by only 1.1 per cent; men who slept in on the weekend showed a 3 per cent increase in weight, while women's body size went up 0.05 per cent.

According to Wright, when people don't sleep enough, they tend to eat more, partly because their body is burning more calories. He added that what happens is "people eat more than they need and therefore gain weight." However, what was surprising is what happened to the group who slept in on weekends.

"Even though people slept as much as they could, it was insufficient," Wright said, adding, "As soon as they went back to the short sleep schedules on Monday, their ability of their body to regulate blood sugar was impaired." Not only that, but the weekend recovery group showed increased sensitivity to insulin in both their muscles and their livers, a result not found in the second group on restricted sleep. That's important, Wright said, because the muscle and liver are two of the most important tissues that take up blood sugar after eating.

He added that it helps the researchers understand why is it that when people do not get enough sleep, they have an increased risk for diabetes. According to him, "short, insufficient sleep schedules will lead to an inability to regulate blood sugar and increases the risk of metabolic disease in the long term."

One of the reasons the weekend group may have been more affected is because their circadian rhythm, or biological clock, had been altered, depriving the body of certain hormones. Another surprising finding of the study was that only men seemed to be able to get recovery sleep throughout the weekend. They slept longer on both Friday and Saturday nights, but women slept longer only on Fridays.