Sleep deprivation causes changes in brain activity that are associated with a desire for high-calorie food items, reports a study in Nature Communications this week. These findings provide further insight into epidemiological evidence that supports a link between sleep loss and obesity.
A steep rise in obesity in industrialized nations anecdotally correlates with a continual decline in sleep duration, in the same populations. It is generally believed that sleep deprivation increases appetitive food desire, but the mechanisms that explain this effect are not fully understood. Matthew Walker and colleagues use brain imaging to study the responses of sleep-deprived individuals as they are presented with images of food of varying calorific values. They find that sleep-deprived individuals show greater activity in areas associated with the motivation to eat, and decreased activity in areas of the brain that evaluate food stimuli, which results in an increased desire for high-calorie foods.
Although further studies are needed to understand why sleep deprivation has an effect on these brain regions, the authors hope that these findings will help to improve public health policies.