Berkeley, CA — Another culprit of the obesity epidemic, sleep deprivation can increase unhealthy food cravings, according to a new study from the University of California Berkeley.
Researchers scanned the brains of 23 healthy young adults after both a normal night’s sleep and a sleepless night. When lacking sleep, the participants exhibited impaired activity in the frontal lobe, which governs complex decision-making and increased activity in areas of the brain that respond to rewards, the study shows. Both effects contribute to junk food cravings.
Researcher Matthew Walker says: “What we have discovered is that high-level brain regions required for complex judgments and decisions become blunted by a lack of sleep, while more primal brain structures that control motivation and desire are amplified. This combination of altered brain activity and decision-making may help explain why people who sleep less also tend to be overweight or obese.”
Participants also each observed a series of 80 food images ranging from high-calorie items such as burgers, pizza and donuts to low-calorie fruits, vegetables and nuts after both the sleepless night and a normal night’s sleep. They rated the food and were given their top choices after the scan — most of which were high-calorie foods following the sleepless night.