Scientists are still trying to understand the full purpose of sleep. But we know one thing it’s probably good for: it may help keep you on that diet.
Researchers scanned the brains of 12 normal weight men, while they looked at images of high and low caloric food—after a night of normal sleep and then also a night without any sleep. After one night of zero sleep the scans showed a high level of activity in the area responsible for hunger, the right anterior cingulate cortex . Now, this response was independent of how hungry a subject claimed he was before scanning, as well as the caloric content associated with the food in the pictures.
Interestingly, after looking at the food images, subjects who went without sleep reported that they were hungrier than those who’d snoozed the night away. But blood glucose levels taken before the subjects were shown images of food were the same as those measured after.
So sleep loss resulted in what scientists call “hedonic stimulus processing”—they had a heightened desire to eat, independent of their blood glucose levels. Take home message: lack of sleep plus Food TV equals phony hunger. And probably real pounds.
[The above text is a transcript of this podcast.]