Observational studies has for a long time shown a correlation between sleep deprivation for an long time. For an example, in 2008, a literature search showed that both children and adults who get too little sleep tend to weigh more than those who get enough sleep.
Now they have finally made a detailed study within a lab clinic proving that sleep deprivation may result in more than 500 additional calories daily.
It studied 17 healthy but sedentary men and women in a lab clinic for 11 days and nights. The participants agreed to spend the entire study period at the facility, where researchers recorded their every movement, through a special monitor the participants wore, and tallied everything they ate, either from a cupboard in their room or food they ordered.
After a three-day baseline period, one group was randomly assigned to sleep and wake whenever they wanted for eight days, while another was intentionally woken up after only two-thirds of their usual sleep time — that amounted to about 80 minutes less sleep per night on average. The group that experienced such restricted sleep tended to eat more the following day, adding 549 extra calories to their usual diet, while those who slept as much as they wanted ate about the same on each of the eight experiment days as they did during the three-day baseline period.
Think about the consequences. When trying to lose weight people are recommended to eat roughly 500 kcal less each day to lose 0.5 kg a week. What would the consequences be if you instead of eating 500 kcal less actually ate 500 kcal more because of sleep deprivation. You would gain 0.5 kg a week!
This is one of the reasons to why sleep is such important to your health.