Key Takeaways
Not eating for 3 hours before bed can help lower blood pressure and blood sugar.  Eating earlier may help your body align with its natural sleep–wake cycle.  Trying this out is a simple, no-cost strategy to improve heart and metabolic health.
If you’re looking to improve your heart health, it may be time to give up your favorite midnight snack. A new study suggests that not eating for 3 hours before sleep can help improve blood pressure, blood sugar, and heart rate—without cutting calories.
A 12-Hour Overnight Fast Was Linked to Better Heart Health
Conducted by researchers at Northwestern Medicine, the study found that when participants at risk for cardiometabolic disease stopped eating at least three hours before bed—extending their overnight fast to about 12 hours without cutting calories—they saw improvements in cardiovascular and metabolic markers.
After making this change, participants saw their nighttime blood pressure drop about 3.5%, their heart rate fall by roughly 5%, and their daytime blood sugar control and insulin response improve.
Although sleep itself is important for regulating cardiometabolic function, anchoring the timing of the extended fasting period to sleep may benefit both daytime and nighttime measures of cardiometabolic health, said study co-author Phyllis C Zee, MD, PhD, the director of the Center for Circadian and Sleep Medicine at Northwestern Medicine.
“The results indicate that when timed to sleep, increasing the fasting duration to a minimum of 12 hours may be a practical and scalable approach to improve and maintain the cardiovascular health span,” Zee said.
Your Body’s Internal Clock May Explain These Benefits
Experts think the circadian rhythm may play a role in this benefit.
Our bodies run on an internal clock that regulates metabolism, hormone release, and heart function across the 24-hour day, according to Angel Planells, MS, RDN, a spokesperson for the Academy of Nutrition and Dietetics who was not involved in the studysaid.
“Eating late, particularly when the body is winding down for sleep, can disrupt these natural rhythms,” he said. “Finishing meals earlier may help keep digestion and metabolic processes aligned with the body’s sleep–wake cycle.”
As evening approaches, melatonin levels rise, signaling the body to prepare for sleep and triggering changes in cardiovascular and metabolic function. Eating during this transition may force the body to manage digestion while simultaneously shifting into “rest mode,” he explained, potentially affecting blood sugar and blood pressure regulation.
This approach also preserves healthy overnight blood pressure and heart rate levels.
“During healthy sleep, heart rate and blood pressure naturally decline, a pattern known as ‘overnight dipping’ that supports cardiovascular health,” Planells said. “Avoiding late-night eating may help preserve this normal drop by allowing the body to fully focus on restorative processes rather than digestion.”
Should You Stop Eating 3 Hours Before Bed?
Planells said the study’s findings are promising but short-term and may not apply to broader populations. Light exposure was also controlled during the study, with participants dimming lights three hours before bed. He said this could have independently influenced circadian rhythms and sleep quality.
Still, for many people, particularly those with elevated cardiometabolic risk, Planells said aligning meals with the body’s natural sleep–wake cycle may be a simple, low-cost strategy to support heart and metabolic health.
“The appealing part is that it doesn’t require cutting calories or following a special diet; it’s primarily about adjusting timing,” he said. “Finishing meals at least three hours before bedtime, opting for an earlier or slightly lighter dinner, and gradually shifting late-night snacks earlier by 15–30 minutes over time are practical ways to ease into the habit.”
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Grimaldi D, Reid KJ, Abbott SM, Knutson KL, Zee PC. Sleep-aligned extended overnight fasting improves nighttime and daytime cardiometabolic function. ATVB. Published online February 12, 2026:ATVBAHA.125.323355. doi:10.1161/ATVBAHA.125.323355
Garaulet M, Qian J, Florez JC, Arendt J, Saxena R, Scheer FAJL. Melatonin effects on glucose metabolism: time to unlock the controversy. Trends in Endocrinology & Metabolism. 2020;31(3):192-204. doi:10.1016/j.tem.2019.11.011
Okamoto LE, Gamboa A, Shibao C, et al. Nocturnal blood pressure dipping in the hypertension of autonomic failure. Hypertension. 2009;53(2):363-369. doi:10.1161/HYPERTENSIONAHA.108.124552
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