Lack of sleep can lead to junk-food cravings, weight gain, study shows


Scientists have found evidence that a lack of sleep causes changes in brain activity that lead to people feeling hungrier and craving more fattening foods.

Researchers have long pointed to a correlation between a steep rise in obesity in industrialized nations and a decline in sleep duration, but until now science has not been able to explain the mechanism.

A team from the University of California used magnetic resonance imaging scans to spot changes in the brain activity of sleep-deprived test subjects.

“These findings provide an explanatory brain mechanism by which insufficient sleep may lead to the development/maintenance of obesity,” they wrote in the journal Nature Communications.

As 23 participants selected items and portion sizes from pictures of 80 food types, their heads were scanned once after a full night of sleep and once after being deprived of shut-eye for a night.

Among the fatigued individuals, the researchers noted impaired activity in brain regions that evaluate appetite and satiation, and a boost in areas associated with craving.