NOT GETTING ENOUGH sleep makes us more likely to reach for unhealthy foods like doughnuts and pizza, according to a new study from the University of California, US.
Researchers measured the brain activity of 23 healthy young adults after a full night’s rest and following a sleepless night. The scans were done as subjects viewed photographs of foods ranging from strawberries to doughnuts, and rated their desire for each item.
Following a poor night’s sleep, the scans showed less activity in the brain’s frontal lobe, which governs decision-making, but increased activity in the brain’s reward region. Subjects were also more apt to say they wanted desire doughnuts, pizza, burgers and other higher-kilojoule, unhealthful choices when they were tired.
“This combination of altered brain activity and decision-making may help explain why people who sleep less also tend to be overweight or obese,” said Matthew Walker, a professor of psychology and neuroscience and senior author of the study, which was published in the journal Nature Communications.
Previous studies have linked poor sleep to greater appetites, particularly for sweet and salty foods, but the latest findings provide a specific brain mechanism explaining why food choices change for the worse following a sleepless night, Walker said.