Health
How Your Internal Clock Affects Heart Health
Health Points
- Disruptions to your body’s 24-hour clock can negatively impact heart health.
- Meal and sleep timing based on your internal rhythm can support better wellbeing.
- Poor sleep and eating late are linked to increased risk of heart disease and related conditions.
The American Heart Association highlights that changes to our body’s natural rhythm, such as daylight saving time, may affect more than just sleep—they can also influence heart health. Experts say aligning daily routines with your internal clock may offer significant benefits, especially for your heart.
“We need to develop methods to determine a person’s internal clock timing and synchronization so that we can personalize recommendations for the timing of sleep, meals, exercise, medications and therapy,” Kristen Knutson, Ph.D., volunteer chair of the American Heart Association Scientific Statement writing group, tells TODAY.com.
This new scientific statement, released in fall 2025, is the first to directly connect the body’s 24-hour circadian rhythm with lifestyle guidance, according to Collin Jeffrey Popp, Ph.D., a registered dietitian and assistant professor at NYU Langone Health.
Circadian rhythm, managed by a part of the brain that responds to light, controls sleep, eating, and other key functions on a roughly 24-hour cycle. Disruption in this system can happen when your schedule doesn’t match your internal needs—such as forcing early wakeups for “night owls.”
“It’s essential for the public to realize that misalignment of our internal body clock to that of the external environment can increase the risk for certain diseases, like high blood pressure, diabetes and obesity,” Popp says.
Research shows that even healthy eaters and regular exercisers may struggle with weight or wellbeing if their schedules clash with their circadian rhythms. Poor or insufficient sleep also raises the risk for cardiovascular disease, notes Dr. Deepak L. Bhatt, director at Mount Sinai Fuster Heart Hospital.
Our circadian clock helps regulate blood pressure and heart rate, says Knutson, so disruptions may impair these protective functions. For instance, blood pressure should dip at night; if it doesn’t, risk for heart problems goes up.
There isn’t a universal best schedule for everyone. “The reason why I can’t [make a schedule] is because it depends on a person’s internal clock timing, so 7 a.m. on the clock on the wall isn’t 7 a.m. for everyone’s internal clock,” Knutson explains.
For meal timing, experts suggest eating breakfast soon after waking—unless you wake earlier than your body wants. Research from 2023 links breakfasts before 8:00 a.m. to a lower risk of Type 2 diabetes. Avoid eating right before bed. “Having dinner 3-4 hours before you plan to go to bed is a good strategy to avoid eating too late in the day,” Knutson adds.
Dinner earlier in the evening supports metabolism and wellbeing. People who dine late may store more fat, burn fewer calories, and experience less satisfaction after eating, studies have found.
For bedtime routines, most adults benefit from eight hours in bed during their natural “biological night.” Typically, this means sleeping between 10 p.m. and midnight for people who aren’t shift workers or dealing with jet lag. A “morning person” might go to bed earlier, while “night owls” may prefer later bedtimes. However, sleeping late—even with adequate hours—can be associated with higher risks for conditions like diabetes, obesity, and heart disease.
“One recommendation I give to folks, regardless of their health goal, is to avoid eating late, and if you need to eat late, make it a small meal,” Popp shares.
Paying attention to your internal clock and adjusting sleep and meal routines can support optimal heart and metabolic health. Try syncing your habits with your body’s natural signals for better wellbeing with age.
