Tick Tock: Circadian Rhythm Resetting Obesity

Tick Tock: Circadian Rhythm Resetting Obesity

What is the Circadian Clock?

The master circadian clock is a 24-hour biological time clock that is encoded in our DNA. Each organ in the human body has its own clock that determines its peak performance times throughout a 24-hour day, and disruptions with this can trigger the onset of a plethora of chronic diseases.² TikTok scrolling through reels in the evening might seem like a harmless pastime to unwind and relax after a full day of work. Unfortunately, the constant exposure to blue light from screens confuses the body’s master circadian clock and blocks the melatonin secretions that are hardwired to release when orange light is present as day passes into night. Each organ has its own clock and performs at different times throughout the day to maintain balance in the body. A disruption in one area generates a cascade of events that affect metabolic changes impacting sleep patterns.

The Trouble with Circadian Rhythm Disruption

Studies have linked disruption in circadian rhythm to gut microbiomes that trigger brain signals controlling metabolic responses. The fluctuations in metabolic responses stemming from a confused circadian clock in turn result in weight gain, insomnia and a slew of resultant hormonal imbalances. In addition to this, confusion of day and night with current shift work trends that spend most of their time indoors during the day or working throughout the night when the body is programmed to be resting and burning calories result in fogginess, and insomnia which are key risk factors for obesity. Acute circadian misalignment also increases insulin secretion. Three weeks of combined sleep restriction and circadian misalignment impairs insulin secretion.¹

How This Relates to Obesity

The current conventional approach to obesity includes quick fixes with medications such as GLP1’s that are heavily marketed to the masses as a magic drug to take care of weight gain. To mitigate the risk involved with a dysfunctional biological clock and avoid needing to rely on injectables that are currently backordered nationwide, applications of functional medicine can be applied to target a potential root cause of obesity that studies have indicated stem from an irregular circadian rhythm. Methods such as time restricted eating, manipulating exposure to circadian lighting and sleep extension routines can help to regulate an abnormal circadian rhythm therefore minimizing the effects of chronic diseases like diabetes, insomnia, and obesity affecting many people.² Diabetes, obesity, depression, bipolar disorder, seasonal affective disorder, and other sleep disorders are all linked to circadian rhythm disruptions.⁴ The following figure depicts sources and primary mechanisms of circadian rhythm disruption.

Figure 1: Sources and Primary mechanisms of circadian rhythm disruptions

What We Can Do

A current study following two groups of mice shows promising results that highlight the benefits of time restricted eating. Rodents that were exposed to a standard American diet with no restrictions consuming calories for a period of 18 weeks were morbidly sick and overweight in comparison to mice that had to consume calories within a time window of 8-10 hours. The sick mice who had no restrictions in the previous study were then exposed to 18 weeks of time restricted food intake, saw improvements in their irregular circadian rhythm and a reduction in excess weight gain.² Time restricted eating can disturb the host circadian system that manages the gut microbiome affecting how we metabolize nutrients, disruptions in microbiota-mediated functions, such as reduced bile acid conjugation and elevated hydrogen sulfide production, can lead to decreased butyrate synthesis. Butyrate is crucial for substrate oxidation and energy regulation in the host. When butyrate levels drop, it can impair metabolic processes, contributing to energy imbalances. Additionally, disturbances in the microbiome’s rhythms may further exacerbate these issues, potentially increasing the risk of obesity.³ Identifying at risk CLOCK genotypes is a new area of research that may help identify individuals who are more susceptible to overeating and gaining weight when exposed to short sleep durations.⁷ So whether you’re dealing with a chronic disease or not, it’s clear that maintaining a stable circadian rhythm should be a priority if you are working to improve your health.

If you’re looking for more information on sleep, we have a couple resources available for you to dig deeper. Check out this blog post and this podcast episode. As always, if you’re ready to start your functional medicine journey, schedule a free discovery call with one of our pharmacists.

Written by Batsinia Hughson, PharmD Candidate and edited by Lindsey Dalton, PharmD

Resources

1. Potter GDM, Skene DJ, Arendt J, Cade JE, Grant PJ, Hardie LJ. Circadian Rhythm and Sleep Disruption: Causes, Metabolic Consequences, and Countermeasures. Endocrine Reviews. 2016;37(6):584-608. doi: https://doi.org/10.1210/er.2016-1083
2. Panda S. Health lies in healthy circadian habits | Satchin Panda | TEDxBeaconStreet. Ted.com. Published 2017. Accessed September 28, 2024. https://www.ted.com/talks/satchin_panda_health_lies_in_healthy_circadian_habits?subtitle= en
3. Parkar S, Kalsbeek A, Cheeseman J. Potential Role for the Gut Microbiota in Modulating Host Circadian Rhythms and Metabolic Health. Microorganisms.2019;7(2) 41.doi:https://doi.org/10.3390/microorganisms7020041
4. Reddy S, Sharma S, Reddy V. Physiology, Circadian Rhythm. Nih.gov. Published October 27, 2018. https://www.ncbi.nlm.nih.gov/books/NBK519507/
5. A, Bøggild H. Gastrointestinal disorders among shift workers. Scand J Work Environ Health. 2010;36(2):85-95. doi:10.5271/sjweh.2897
6. Sleep Disorder Treatments – Sleep Disorder Treatments | NHLBI, NIH. (2022, March 24). Www.nhlbi.nih.gov. https://www.nhlbi.nih.gov/health/sleep-disorder-treatments
7. Valladares, M., Obregón, A. M., & Chaput, J. P. (2015). Association between genetic variants of the clock gene and obesity and sleep duration. Journal of physiology and biochemistry, 71(4), 855–860. https://doi.org/10.1007/s13105-015-0447-3