Impact of Sleep on Appetite Regulation: Insights from German Neuroscientists

Sleep Deprivation and Its Effects on Brain Function

German neuroscientists have unveiled significant findings regarding the relationship between sleep and appetite regulation. A meticulously controlled laboratory experiment revealed that even one night of insufficient sleep can trigger brain changes that enhance the dopamine response associated with eating. This research builds on the established correlation between sleep deprivation and obesity, indicating that sleep duration is linked to variations in body mass index (BMI) and body fat percentage.

Mechanisms Behind Sleep Deprivation and Obesity

Researchers suggest that sleep deprivation may disrupt the balance of appetite hormones, while others believe it alters the brain’s reward systems. Both of these factors could contribute to increased food intake and a higher likelihood of obesity.

Research Methodology

To explore the mechanisms connecting sleep deprivation and obesity, a team of researchers in Germany conducted a study involving 32 healthy, normal-weight male volunteers. After an initial physical evaluation, participants visited the laboratory for two separate evening sessions. During these sessions, all volunteers were provided with a calorie-controlled dinner. Following the meal, half of the participants returned home for a normal night’s sleep, while the other half remained awake at the study center throughout the night.

Assessment and Findings

The next morning, all volunteers returned to the laboratory for testing. Blood samples were collected at the start and end of the experimental session to analyze appetite hormone levels. Participants also engaged in a decision-making assessment, where they evaluated and selected food and non-food rewards while undergoing a brain scan.

The results indicated that appetite hormone levels remained unchanged despite sleep deprivation. However, the sleep-deprived volunteers exhibited a heightened preference for food over non-food items during the assessment. Brain scans demonstrated increased activity in the reward-processing regions of the brain among these individuals.

Conclusion: Reward System Changes Linked to Overeating

Researchers concluded that the increased valuation of food following sleep deprivation is attributable to alterations in the brain’s reward system rather than hormonal changes. Brain scans indicated significant shifts in reward system activity after just one night of sleep loss. These findings suggest that such changes may contribute to overeating, weight gain, and obesity.

References

Rihm JS, Menz MM, Schultz H, et al. Sleep deprivation selectively up-regulates an amygdala-hypothalamic circuit involved in food reward. J Neurosci 2018;10.1523/JNEUROSCI.0250-18.2018.
Press release. Society for Neuroscience. 17 Dec 2018. “Unraveling the link between obesity and sleep.” https://www.eurekalert.org/pub_releases/2018-12/sfn-utl121118.php