Blame poor sleep for unhealthy cravings for pizzas

Sleep deprivation can make us crave for junk food more than healthy food, a new study has revealed.

Researchers at UC Berkeley scanned the brains of 23 healthy young adults, first after a normal night's sleep and next, after a sleepless night by using functional magnetic resonance imaging (fMRI).

They found impaired activity in the sleep-deprived brain's frontal lobe, which governs complex decision-making, but increased activity in deeper brain centers that respond to rewards. Moreover, the participants favored unhealthy snack and junk foods when they were sleep deprived.

According to Matthew Walker, the senior author of the study, high-calorie foods became significantly more desirable when participants were sleep-deprived.

In this study, researchers measured brain activity as participants viewed a series of 80 food images that ranged from high-to low-calorie and healthy and unhealthy, and rated their desire for each of the items. As an incentive, they were given the food they most craved after the MRI scan.

Food choices presented in the experiment ranged from fruits and vegetables, such as strawberries, apples and carrots, to high-calorie burgers, pizza and doughnuts. The latter are examples of the more popular choices following a sleepless night.

The study is published in the journal Nature Communications.