Study: Avoiding Late-Night Meals Could Significantly Benefit Heart Health

Abstaining from food three hours before bedtime may boost cardiovascular health, according to promising new research from Northwestern University. The study found that extending overnight fasting and avoiding late meals led to meaningful improvements in heart function and blood sugar control among middle-aged and older adults.

The eight-week study, published in the journal Arteriosclerosis, Thrombosis and Vascular Biology, involved 39 overweight and obese participants between 36 and 75 years old. The research team, focusing primarily on individuals at higher risk for cardiometabolic disease, discovered that timing meals to align with the body’s natural rhythms produced notable health benefits.

“Timing our fasting window to work with the body’s natural wake-sleep rhythms can improve the coordination between the heart, metabolism and sleep, all of which work together to protect cardiovascular health,” said Dr. Daniela Grimaldi, research associate professor of neurology in Northwestern’s division of sleep medicine and the study’s first author.

Participants who completed an extended overnight fast of 13-16 hours and stopped eating at least three hours before bedtime showed significant physiological improvements compared to those maintaining their usual eating patterns. These improvements included a 3.5% reduction in blood pressure and a 5% drop in heart rate.

Researchers also observed more natural fluctuations in these measurements during sleep – an important indicator of cardiovascular health. The fasting participants’ hearts demonstrated healthier patterns, beating faster during daytime activity and slowing appropriately during nighttime rest.

Beyond heart metrics, participants who abstained from late-night eating showed improved daytime blood sugar control. Their bodies responded more efficiently to glucose challenges, suggesting enhanced insulin function and steadier blood sugar levels – critical factors in preventing type 2 diabetes.

Dr. Grimaldi emphasized that the three-hour pre-sleep fasting window is particularly important because it coincides with rising melatonin levels as the body transitions toward sleep. Eating during this critical period can disrupt metabolism and counteract the body’s natural rhythms.

Sleep expert Dr. Wendy Troxel, who was not involved in the study, highlighted the research’s impressive 90% adherence rate among participants. “High rates of compliance suggest that this approach may be both feasible and sustainable in real life and could have a demonstrable impact on improving cardiometabolic health,” she noted.

The findings add to mounting evidence connecting sleep and circadian rhythms to heart health. The American Heart Association now includes healthy sleep among its “Life’s Essential 8” pillars for cardiovascular wellbeing.

The importance of this research is underscored by alarming statistics. Northwestern University reports that only 6.8% of U.S. adults had optimal cardiometabolic health from 2017 to 2018. Cardiometabolic conditions can lead to chronic illnesses including type 2 diabetes, heart disease, and non-alcoholic fatty liver disease. According to the CDC, heart disease remains the leading cause of death globally.

Time-restricted eating has gained popularity recently for its potential benefits to heart health and weight management. However, this study breaks new ground by focusing on how fasting aligns with sleep schedules rather than simply measuring fasting duration.

Looking ahead, researchers plan to conduct larger, multi-center trials to determine whether these benefits persist long-term and translate into reduced cardiovascular events or diabetes. Future studies will also explore potential benefits for people with existing hypertension or diabetes, who might see the greatest improvements.

“We also want to explore how this approach combines with other behavioral interventions, like exercise or morning light exposure, to develop more comprehensive strategies for cardiometabolic health,” Dr. Grimaldi added.

The research team acknowledged limitations, including the high percentage of female participants (80%), which restricts the ability to draw conclusions about gender differences. Additionally, while the 7.5-week study period was sufficient to demonstrate physiological changes, it wasn’t long enough to assess effects on weight or long-term health outcomes.