Are you hit by sudden cravings even after having a full-course meal? Blame it on the lack of sleep. Lack of sleep has long been linked to slow metabolism, making unhealthy food choices and weight gain and now new research shows that it can also initiate hunger.
According to a new study, lack of sleep not only leads to increased caloric intake but also stimulates changes in the hedonic aspects of food consumption. Simply put, the study showed that sleep loss leads to overeating. This is particularly because it amplifies and extends blood levels of a chemical signal that enhances the joy of eating, particularly the guilty pleasures gained from sweet or salty, high fat snack foods.
During the study, sleep-restricted study subjects reported higher scores for hunger and stronger desire to eat. When given access to snacks, they ate nearly twice as much fat as when they had slept for eight hours. "We found that sleep restriction boosts a signal that may increase the hedonic aspect of food intake, the pleasure and satisfaction gained from eating," said Erin Hanlon, research associate at the University of Chicago in the US.
The effects of sleep loss on appetite were most powerful in the late afternoon and early evening, times when snacking has been linked to weight gain, the researchers noted. Published in the journal Sleep, the study helps us to understand how the endocannabinoid system, a group of endogenous cannabinoid receptors located in the mammalian brain and involved in the regulation of appetite, connects short sleep and weight gain.
Researchers recruited 14 healthy men and women in their 20s and monitored their hunger and eating habits in two situations: one four-day stay during which they spent 8.5 hours in bed each night (averaging 7.5 hours of sleep), and another four-day stay when they spent only 4.5 hours in bed (4.2 hours asleep). After the period of restricted sleep, study subjects reported a significant increase in hunger levels. This was prominent soon after their second meal of the day, the time when endocannabinoid levels were the highest.
This increase in circulating endocannabinoid levels could be a mechanism by which recurrent sleep restriction results in excessive food intake, particularly in the form of snacks, despite minimal increases in energy need, the researchers maintained.
Obesity and lack of sleep have become extremely common. According to The National Sleep Foundation (NSF), adults require 7 to 9 hours of sleep everyday while school-age kids need 9-11 hours of sleep.
