Circadian rhythms, often referred to as the body’s “internal clock,” are 24-hour cycles that govern various bodily functions, including hormone levels and the sleep-wake cycle. These rhythms are crucial for maintaining overall health, but when they become misaligned, they can lead to significant health problems.
A recent study by researchers at Oregon Health & Science University (OHSU) highlights the potential metabolic risks for people with overweight or obesity when their circadian rhythms are out of sync. The study, published on August 20 in The Journal of Clinical Endocrinology & Metabolism, reveals that these risks can vary between males and females.
Linking Circadian Rhythm Misalignment and Metabolic Health
The study’s findings suggest that poorly aligned circadian rhythms may contribute to negative metabolic effects, which could exacerbate the health risks associated with overweight and obesity. Researchers emphasize that while these initial findings are promising, more research is needed to fully understand the potential benefits of realigning circadian rhythms.
The Role of Sleep in Weight Management
The relationship between sleep and weight has been well-documented. Insufficient sleep has been linked to weight gain, and circadian misalignment may increase the risk of obesity. Research shows that people who do not get enough sleep tend to consume more calories the following day, which can lead to weight gain over time.
Dr. Jacob Teitelbaum, a board-certified internist not involved in the study, explained the importance of circadian rhythms. “The circadian rhythm is the critical ‘orchestra conductor’ for your body,” he said. “It regulates the proper timing of your hormonal and immune systems, and numerous other functions.”
Sex-Specific Effects of Circadian Misalignment
In the OHSU study, 15 males and 15 females with overweight participated. Researchers measured their body composition and analyzed blood samples to assess their circadian rhythm alignment. The study focused on dim-light melatonin onset (DLMO), which indicates when the body begins to produce melatonin, a hormone that signals the body to prepare for sleep.
The results showed distinct differences between males and females with misaligned circadian rhythms. Males experienced higher levels of abdominal fat, elevated blood fat (triglycerides), and a greater risk of metabolic syndrome. In contrast, females showed a higher percentage of body fat, increased blood sugar levels, and a higher resting heart rate.
Dr. Brooke Shafer, a co-author of the study, noted the surprising nature of these sex-specific differences. “These findings emphasize that there is no one-size-fits-all approach to maintaining healthy behaviors,” she said. The differences in how sleep habits affected glucose and triglyceride levels were particularly noteworthy, highlighting the complex relationship between circadian rhythms and metabolic health.
Potential for Reducing Health Risks
The study suggests that circadian disruption may not only contribute to weight gain but also increase the risk of negative health outcomes in a sex-dependent manner. The researchers hope that by optimizing circadian alignment, it may be possible to reduce these risks, particularly for those already dealing with overweight or obesity.
The next phase of research will focus on understanding sex-specific differences in health markers for individuals who experience extreme sleep disturbances, such as night shift workers.
How to Realign Your Circadian Rhythm
Although the study was small, it adds to the growing body of evidence linking circadian misalignment with negative health outcomes. The good news is that most people can readjust their body clock with proper sleep habits, which could potentially lower their risk of metabolic diseases.
Experts recommend several strategies to help realign your circadian rhythm:
Maintain a consistent sleep schedule, even on weekends.
Get exposure to natural light in the morning to help set your internal clock.
Limit screen time and bright lights in the evening to signal to your body that it’s time to wind down.
Gradually adjust your bedtime and wake time by 15–30 minutes each day if needed.
Additionally, Dr. Cherilyn Davis, a pediatrician not involved in the study, suggests optimizing your sleep environment by keeping it cool, dark, and comfortable. Avoiding caffeine and late-day exercise can also help maintain a healthy circadian rhythm.
By adopting these habits, individuals may not only improve their sleep quality but also reduce their risk of metabolic disorders linked to circadian misalignment.
