Heart health specialists are warning that disruptions to the body’s natural circadian rhythm—the internal 24-hour clock that governs sleep, hormones, digestion, and body temperature—can have serious health consequences, including a higher risk of heart disease and diabetes.
A new scientific statement from the American Heart Association (AHA) highlights growing evidence that irregular sleep, eating patterns, shift work, jet lag, and nighttime light exposure can interfere with the body’s ability to regulate metabolism, blood pressure, and hormones. These disruptions, experts say, may contribute to obesity, hypertension, and type 2 diabetes.
“Regular interruptions to the body clock are much more than simple inconveniences like staying up too late or waking up too early,” said Dr. Kristen Knutson, an associate professor of neurology at Northwestern University in the United States. “Aligning our daily behaviours—when we sleep, eat, and move—with our internal clock is important to support optimal cardiometabolic health.”
To help people realign their body clocks and improve wellbeing, heart health experts have outlined several practical steps:
1. Get light in the morning, avoid it at night
Light is the main environmental signal that helps the brain regulate the circadian rhythm. Experts recommend getting natural daylight early in the morning to improve alertness and mood. At night, however, even small amounts of light—especially from screens—can suppress melatonin, the hormone that promotes sleep.
2. Keep a consistent sleep schedule
Going to bed and waking up at the same time each day, including weekends, helps maintain the body’s internal rhythm. The AHA notes that irregular sleep patterns have been linked to obesity and metabolic disorders, even in people who get sufficient sleep overall.
3. Eat earlier in the day
Late-night meals or irregular eating patterns can disrupt the body’s metabolic rhythm, particularly in organs like the liver and pancreas. Research suggests that eating earlier, such as having breakfast before 8 a.m., is associated with better heart and metabolic health.
4. Time your exercise
While the best time to work out varies from person to person, exercise timing can influence blood pressure, glucose control, and sleep quality. Morning or afternoon workouts may help advance the body clock, while evening exercise can delay it.
5. Monitor your rhythm
Although the circadian rhythm can be difficult to measure directly, wearable devices that track heart rate and skin temperature may help individuals understand their natural patterns.
Knutson said it’s time for both individuals and healthcare professionals to pay more attention to the body’s internal clock. “Everyone has an internal clock, and it’s time we start listening to it,” she said.
