Sleep, Metabolism and Social Jet Lag: How Circadian Rhythms Can Control It All 

In our blog earlier this month, we demystified the concept of circadian rhythm—that 24-hour schedule your body should naturally stick to. But what if it doesn’t?

For those who suspect they struggle with circadian rhythm disruptions, the impacts are significant. Advances in genetic studies of circadian rhythms have led to the recognition that the circadian system is tightly coupled with processes controlling both sleep and metabolism.

Read on for some nitty gritty details on how your rhythms affect these two very significant parts of your health and life. 


How can I tell my circadian rhythms are “off”? 

Your circadian rhythms are easily disrupted. This can present itself in the form of the occasional poor night sleep, all the way to what are called circadian rhythm disorders, which are often related to the sleep/wake cycle. Some symptoms of such disorders include difficulty initiating sleep, difficulty maintaining sleep, nonrestorative or poor quality sleep or daytime sleepiness.

Additionally, your metabolism can be affected. Some of our modern-day habits—like artificial light, working late into the night, and voluntarily reducing the number of hours we sleep—can have negative effects on the way our bodies process food. Research has shown that “these common disorders of circadian behavior and sleep are associated with increased hunger, decreased glucose and lipid metabolism, and broad changes in the hormonal signals involved in satiety.” 


How to Optimize Your Sleep

Maintain “Good Sleep Hygiene.” First and foremost, stick to consistent sleep and wake times. Set an alarm for the same time every morning—even when it hurts! Secondarily, avoid napping and try to use your bed for sleeping only. Steer clear of exercise at least four hours prior to bedtime, and avoid large meals and excessive fluids before you hit the hay. 

Timed Light Exposure.Executed under the careful watch of a sleep specialist, timed light exposure therapy uses appropriately timed exposure to light to help delay your biological clock. The sleep specialists works with you to decide the timing of the light exposure based on your symptoms and life circumstances. A common way to start treatment is to begin light exposure shortly before your usual time of spontaneous awakening, artificially simulating dawn. To do this at home, you could try a nightlight that slowly lights up your room at a designated time in the morning. 


How to Optimize Your Metabolism

Timed Meals: This theory takes us way back. For thousands of years, without electricity and light bulbs, our ancestors couldn’t hunt, gather or eat in the dark. Therefore, experts believe our bodies expect to be fed only during the daytime. The concept is pretty simple: eat when the sun is up. Ideally, there’s a 12-hours gap between dinner and breakfast. Make breakfast and lunch your biggest meals of the day, striving to get 75 percent of your nutrition before 3 p.m. Learn more about this method, coined “The When Way” by Michael F. Roizen, M.D. and Michael Crupain, M.D., M.P.H. 


Everyone’s circadian rhythms are different, and circadian rhythm disorders come in all shapes and sizes. Some are even referred to as “social jet lag,” when your biological clock is so different from the rest of society around you that you can’t keep up. These rhythmic differences can wreak havoc on both mental and physical health, as well as careers and relationships.

If you suspect you may be suffering from a circadian rhythm disruption, experiment with self-led changes at home, but don’t hesitate to reach out to a trained professional. In the ever-changing, 24/7 society in which we live, we should all strive to prioritize the health and natural rhythms of our bodies and minds.