How Sleepless Nights Can Make You Fat

Sharon Moore August 09, 2013

Staying up late makes your brain crave for fatty, high-calorie snacks like cakes and doughnuts instead of whole grains or leafy vegetables, according to a new study by the UC Berkeley. These new findings add to the growing evidence that sleep deprivation and obesity goes hand in hand.

23 young healthy individuals have undergone functional magnetic resonance imaging (fMRI) scan, first after a normal night sleep, and next, after a sleepless night. Following either a sleep-deprived or a good night sleep, the participants were shown 80 food images that ranged from high-to low-calorie, and healthy and unhealthy, whilst researchers measured their brain activities.

The results show an increased activation in the brain regions related to rewards and impaired activity in the frontal lobe – the part which governs complex decision-making, when the participants were sleep deprived. Behaviour-wise, the participants tend to reach for unhealthy snacks and junk foods when they lack enough sleep.

“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 study senior author Matthew Walker, and a UC Berkeley professor of psychology and neuroscience.

"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,"

Whilst previous studies have already suggested a link between poor sleep and increased appetite, particularly for sweet and salty foods, the current study is the first to provide evidence on a specific brain mechanism that explains why people tend to have unhealthy food choices following a sleepless night.

According to Stephanie Greer, the study lead-author and a doctoral student in Walker’s Sleep and Neuroimaging Laboratory at UC Berkeley, their findings shed light on how the brain becomes impaired by sleep deprivation.

Walker added that having enough sleep is one factor that can help promote weight control by helping the brain make better, healthier food choices.

Their work was published in the journal Nature Communications.

Source of this article:

The impact of sleep deprivation on food desire in the human brain