Obesity is an epidemic in both adults and children in the U.S. Obesity in the teenage population has quadrupled in the past 30 years (1). A link exists between how much a person sleeps and how much they weigh. Inadequate sleep could increase the chances of becoming obese in many possible ways:
Disrupted Balance of Key Hormones that Control Appetite
Some studies reveal the hormone responsible for signaling hunger (ghrelin) increases with inadequate sleep while the hormone responsible for telling your brain you are full (leptin), decreases with inadequate sleep. Therefore, a sleep deprived person is more likely to eat past the point they normally would compared to when they are well rested. Lack of sleep affects metabolism and endocrine function. There is less glucose tolerance and insulin sensitivity in the setting of sleep deprivation. (2)
More Calories are Consumed and Less Calories are Burned
Other studies have shown people tend to consume more calories when they have not had enough sleep. They are looking for a quick energy-fix to combat their fatigue. One study revealed an increase of 385 calories was consumed each day with sleep deprivation.(3) Inactivity is another possible issue as those who are sleep deprived are too tired to exercise and are more likely to be inactive in general, leading to weight gain. Although the research is less clear on this latter issue.
While the mechanisms involved are still under investigation, there is certainly enough information to warrant greater attention to the amount of sleep children obtain to ensure they remain healthy into adulthood. A single analysis of the many studies looking at the relationship between obesity and sleep of 24,821 subjects revealed those children sleeping for a short duration had 2 times the risk of being overweight or obese compared to those sleeping for longer. (4)
Another large study involving participants between the age of 16-21 revealed teenagers who were not obtaining adequate sleep at age 16 were 20 percent more likely to be obese by the age of 21.(5) This is concerning as obesity increases the risk of other health problems including diabetes and heart disease. Therefore, one needs to consider sleep when looking at ways to prevent obesity to prevent the potential development of chronic disease.
Historically, the focus on obesity treatment and prevention has been on good nutrition and exercise, which are certainly important key components. However, there is no amount of exercise or healthy food that can offset the adverse effects of inadequate sleep.
Not only does obtaining more sleep aid in preventing obesity, there is evidence to show teenagers who are already overweight have an easier time losing weight if they are obtaining adequate sleep. (6) Therefore, a teenager who has the potential to obtain more sleep if school start times are shifted later has the opportunity to benefit in respect to less risk for obesity. As noted above, a healthy weight also translates into less risk of chronic disease. Optimal health involves a combination of regular activity, good nutrition AND quality sleeping.
KEY ARTICLES:
- https://www.cdc.gov/healthyschools/obesity/facts.htm
- Leproult R, Van Cauter E. Role of Sleep and Sleep Loss in Hormonal Release and Metabolism. Endocrine development. 2010;17:11-21. doi:10.1159/000262524.
- Khatib, Harding, Darzi and Pot. The effects of partial sleep deprivation on energy balance: a systematic review and meta-analysis European Journal of Clinical Nutrition advance online publication 2 November 2016. doi: 10.1038/ejcn.2016.201
- Fatima Y, Doi SAR, Mamun AA. Longitudinal impact of sleep on overweight and obesity in children and adolescents: a systematic review and bias-adjusted meta-analysis. Obes Rev. 2015;16(2):137–149
- Suglia, S. F., Kara, S., & Robinson, W. (2014). Sleep duration and obesity among adolescents transitioning to adulthood: Do results differ by sex? The Journal of Pediatrics, 165(4), 750–754. http://doi.org/10.1016/j.jpeds.2014.06.052