How Modern Lifestyles Affect Our Body Clock

In today’s fast-paced world, our habits have dramatically changed. We stay up late, use screens constantly, skip meals, and often work odd hours. While this might seem normal, science now shows these lifestyle choices can disturb our body’s natural rhythm—and even raise the risk of obesity and cancer.

What Is the Circadian Rhythm?

Your circadian rhythm is your body’s internal clock. It controls things like sleep, hormone levels, and even metabolism. This clock is mainly regulated by the brain’s “master clock” called the suprachiasmatic nucleus (SCN), which responds to light and darkness. When this clock is disrupted, it can throw off your body’s balance in more ways than one.

Modern Habits That Disrupt the Body Clock

Certain lifestyle habits have been shown to interfere with the circadian rhythm. These include:

• Shift work or irregular sleep schedules
• Excessive screen time or artificial light at night
• Skipping meals, fasting, or eating at odd hours
• Frequent consumption of alcohol, caffeine, or high-sugar foods

These behaviors can affect hormone levels, especially cortisol (the stress hormone) and melatonin (the sleep hormone). When these hormones become imbalanced, it can lead to weight gain and even make the body more vulnerable to cancer.

Cortisol, Fat Accumulation, and Cancer Risk

Cortisol follows a daily rhythm—highest in the morning and lowest at night. But when your lifestyle disrupts this pattern, cortisol levels can remain high for long periods. This promotes fat storage, especially around the abdomen. Excess fat doesn't just sit there—it creates a microenvironment that can help cancer cells survive, grow, and resist treatment.

Research shows that people exposed to more artificial light, those who sleep poorly, or those who work night shifts often have higher cortisol levels—and a greater chance of developing obesity and certain types of cancer, including breast and prostate cancers.

Melatonin: The Silent Protector

Melatonin is often called the “sleep hormone,” but it does much more than that. It helps regulate metabolism, boosts the immune system, and even has anti-cancer properties. Unfortunately, melatonin production drops significantly with light exposure at night, aging, and stress.

Low melatonin levels have been linked to increased cancer risks. Studies show that melatonin can reduce fat storage and even slow the growth of cancer cells. Some clinical trials are exploring how melatonin supplements could support cancer treatment and weight management, especially in people with disrupted circadian rhythms.

What Can We Do About It?

Small changes can protect your circadian health:

• Stick to a regular sleep schedule
• Limit screen time and artificial light at night
• Eat meals at consistent times
• Reduce alcohol, sugar, and caffeine intake—especially before bed
• Consider talking to a healthcare provider about melatonin if your sleep or lifestyle is off track

Conclusion

Your body’s internal clock is more than just a sleep timer—it’s a powerful system that affects weight, immunity, and cancer risk. By respecting your circadian rhythm and adopting healthier daily habits, you may reduce your risk of obesity and certain cancers, while improving overall wellbeing.

Reference: https://pubmed.ncbi.nlm.nih.gov/39518143/