For their study, the team of researchers tracked the metabolism, sleep patterns and eating habits of 16 healthy men and women in a two-week experiment. According to the researchers, they did this because they wanted to see if inadequate levels of sleep may have an impact on your weight, behaviour or physiology. For the first week of the experiment, the participants were split into two groups, with the first group sleeping for nine hours a night whilst the second had to stay awake until midnight, and then were only allowed to sleep for five hours.
In the second week, those in the second group were given the same sleep restrictions of sleeping only five hours a night, whereas the first group was allowed to sleep for an extra four hours nightly. All of the participants had unlimited access to food throughout the study. The results of the study, which were published last month in The Proceedings of the National Academy of Sciences, showed that staying up late and getting just five hours of sleep increased a person’s metabolism, and sleep-deprived participants actually burned an extra 111 calories a day.
Yet, those who slept less ended up eating far more than those who got nine hours of sleep, and so the sleep-deprived subjects had gained an average of two pounds by the end of the first week. When members of the group that had originally slept nine hours were restricted to just five hours during week two, the researchers found that they also gained weight. The other group, on the other hand, managed to lose some of the weight they had gained in that first sleep-deprived week. Therefore, it seems you have another reason to get your recommended seven to nine hours of sleep a night!