Sleep deprivation can cause changes in brain activity that increase our desire for high-calorie food items, new research has found. This is bad news for sleep walkers, with sleep loss once again linked to obesity.
A new study published in Nature Communications argues that the steep rise in obesity in industrialized nations correlates with a continual decline in sleep. Researchers used brain imaging to study the responses of sleep-deprived individuals as they were presented with images of food containing varying calorie levels. They found that sleep-deprived individuals showed greater activity in areas associated with the motivation to eat when shown high-calorie foods.
These findings establish a disrupting impact of sleep deprivation that blunts activity in established appetitive evaluation regions within the human frontal and insular cortex during food desirability choices, yet a converse subcortical amplification of reactivity within the amygdala, known to code salience in the context of food decisions.
Furthermore, these neural changes were associated with a significant increase in appetitive desire for weight-gain promoting (high-calorie) food items following sleep loss, the magnitude of which was proportional to the subjective severity of sleep loss across participants.
This is far from the first time a study has made these claims: just this year researchers from the University of Pennsylvania found people who lose a lot of sleep eat more fatty foods and gain more weight. The study used the largest, most diverse sample to date — 225 healthy adults ages 22 to 50 — and it was also done in a controlled sleep lab.
The authors hope that their findings will help to improve public health policies.
"In summary, these findings provide a novel brain mechanism by which sleep loss may lead to the development and/or maintenance of obesity through the selection of foods carrying obesogenic (weight-gain) potential, helping to explain the significant association between reduced sleep time and obesity reported in population-level studies," the paper concluded.