(NaturalNews) Missing a night of sleep causes you to eat more high-calorie foods the next day, even if you're already full, according to a study conducted by researchers from Uppsala University and published in the journal Psychoneuroendocrinology.
"Bearing in mind that insufficient sleep is a growing problem in modern society, our results may explain why poor sleep habits can affect people's risk to gain weight in the long run," lead author Pleunie Hogenkamp said.
In a prior study, published in the Journal of Clinical Endocrinology & Metabolism, the researchers had found that when young men of normal weight went for a single night without any sleep, they underwent a significant increase in the activity of a brain region associated with increased appetite.
In the new study, the researchers sought to test whether this activity was actually associated with increased eating. 16 men of normal weight were allowed to choose as much food as they wanted from a buffet under four separate conditions. In one condition, they had already eaten breakfast and had slept for about eight hours the prior night. In a second condition, they had gotten enough sleep but had not eaten breakfast. In the third and fourth conditions, they had not slept at all the night before, and either had or had not eaten breakfast. The buffet consisted of seven food items and six snack items.
Sleepless men overeat even when full
The researchers found that after a night without sleep, the men took significantly larger portions of calorie-dense foods from the buffet, even when they had already eaten breakfast and were therefore presumably full.
"We were not overly surprised by the difference in their selected portion sizes," Hogenkamp said, because of the prior research.
"However, we were surprised to find a clear differentiation between the two groups after they had eaten breakfast. Even when sleep-deprived participants were satiated, they still opted for larger, higher-calorie meals than their rested counterparts. We did not expect this to be the case after breakfast."
The researchers do not yet know why a night without sleep causes an increase in high-calorie snacking.
"We suspect that after sleep loss, the reward centers of the brain become more sensitive to food-based stimuli," Hogenkamp said.
The findings strongly suggest that lack of sufficient sleep may contribute to weight management problems, the researchers noted. How much sleep you get seems to have a bigger impact than how good the sleep is, Hogenkamp said.
"Quality of sleep definitely plays a role, but then it is closely connected with the amount of sleep that a person gets," she said. "Most research literature in this area points to the fact that the longer you sleep, the better the quality of your sleep is likely to be."
The findings suggest that getting more sleep may also help you lose weight, although further studies would be needed to prove that connection.
"It would be nice to conduct a follow-up study to find out whether longer periods of sleep promote weight loss amongst dieting patients," Hogenkamp said.