Courtesy of Jonah Bromwich, at the New York Times:
A study published on Tuesday in the journal SLEEP suggested that the brain receptors that can lead the sleep-deprived to crave unnecessary food were the same as those activated by marijuana. Essentially, not sleeping can give you a ferocious case of the munchies.
The study took a close look at receptors affected by endocannabinoids — so named for cannabis, the marijuana plant — which it found were closely involved in the food cravings that come from sleep deprivation. Sleep restriction in the study’s subjects led to amplified endocannabinoid levels in the blood, leading to hunger pangs, which generally intensify in the early afternoon, to increase further.
Subjects who were deprived of sleep said that they felt hungrier, and had more trouble controlling themselves when faced with the snacks. They ended up consuming nearly twice as much fat and protein as the control group. (There was not a significant difference between the calories consumed by each group during regular meals.) Previous studies have shown that the sleep-deprived are particularly vulnerable to foods that are high in fat and carbohydrates.
I can confirm these results from my own anecdotal evidence.