In the study, from Perelman School of Medicine at the University of Pennsylvania, 44 particants (ages 21-50), were given unlimited access to food and drink during the day and only allowed four hours of sleep each night for three nights. On the fourth night, 20 participants were given the same unlimited food and drink access, while the other 24 were only given water from 10 p.m. until they were allowed to sleep at 4 a.m.
At 2 a.m. every night, all subjects completed tests to measure their working memory, cognitive skills, sleepiness, stress levels, and mood. On the fourth night, participants who fasted performed better on reaction time and attention lapse tests than those subjects who ate during those late-night hours. What’s more, the subjects who ate experienced heavy performance decline on the cognitive tests on the fourth night of sleep deprivation, whereas those who fasted did not.
The next time you find yourself unable to fall asleep or stay asleep, don’t go for the Twinkie. ("Adults consume approximately 500 additional calories during late-night hours when they are sleep restricted," said study author David F. Dinges, PhD in a release.) Fast during those late-night hours instead and you can curb the concentration and alertness deficits that accompany sleep deprivation.