Stopping Your Meals Just Three Hours Before Bed Can Significantly Boost Heart Health

At 10:30 pm, the kitchen light is still on. A late snack, maybe a scroll through the phone, one more episode before bed—it feels harmless, right? In fact, this has become the normal night routine for many people around the globe, but what they don’t know is that this nightly habit is quietly working against their hearts.

Curious about what this late-evening pattern might be doing inside the body, a team of researchers at Northwestern University decided to investigate. Instead of asking people to cut calories or overhaul their diets, they tested a simpler idea: stop eating earlier in the evening and extend the overnight fasting window so it overlaps more fully with sleep.

Their findings suggest that this small shift in timing may help restore healthier heart rhythms and improve blood sugar control in adults at elevated risk of heart disease.

“It’s not only how much and what you eat, but also when you eat relative to sleep that is important for the physiological benefits of time-restricted eating,” Phyllis Zee, one of the study authors and an expert in sleep medicine, said

Eating late is an open invitation to heart problems

Unfortunately, only a small fraction of adults today have ideal cardiometabolic health. In fact, earlier US data showed that just 6.8 percent met optimal standards. This matters because poor cardiometabolic health increases the risk of type 2 diabetes, fatty liver disease and cardiovascular disease.

Scientists have long known that the body runs on a circadian rhythm — an internal 24-hour timing system. Blood pressure is meant to dip at night. Heart rate should slow during sleep. Hormones that control blood sugar follow predictable daily cycles.

However, modern habits disturb this flow. Late meals send signals that it is still daytime, while bright indoor lighting (including from devices) delays the body’s preparation for sleep. Over time, this mismatch may strain the cardiovascular and metabolic systems.

According to researchers, time-restricted eating, i.e., limiting food to a daily window, has emerged as a promising solution for this problem. However, most studies have focused on the length of fasting, not whether fasting aligns with sleep. 

This missing piece became the focus of the current study. 

A habit that restores heart rhythm

The study authors followed 39 overweight or obese adults between the ages of 36 and 75, all considered at elevated cardiometabolic risk. It lasted 7.5 weeks. About 80 percent of the participants in the intervention group were women.

Participants were divided into two groups. One continued their usual pattern, fasting about 11 to 13 hours overnight. The other group extended their overnight fasting to 13 to 16 hours and stopped eating at least three hours before bedtime.

No one was told to reduce calories and there was no weight-loss target. The only variable was timing. Both groups were also instructed to dim their lights for three hours before bed. Lower light levels help signal the brain that nighttime has begun, reinforcing natural circadian rhythms.

Importantly, adherence reached nearly 90 percent, suggesting the routine was manageable for participants.

After seven and a half weeks, the extended-fasting group showed measurable physiological shifts. Nighttime blood pressure fell by 3.5 percent. Heart rate during sleep dropped by 5 percent. 

These changes restored a stronger day–night pattern: higher cardiovascular activity during the day, lower during rest. This rhythm — rising with activity, dipping during sleep — is considered healthier for the heart. Blood sugar regulation improved as well. When participants consumed glucose, their pancreas released insulin more effectively. 

“Extended overnight fasting improved secondary measures of nighttime autonomic function and morning oral glucose tolerance, including lower nighttime heart rate, higher heart rate variability, lower nighttime cortisol, and during the Oral Glucose Tolerance Test, lower glucose level, and higher 30-minute insulinogenic index, indicating improved acute insulin response,” the study authors said.

All of this suggests better control over blood sugar levels during the day. In simple terms, the body’s systems appeared to coordinate more smoothly when eating stopped earlier and fasting overlapped more fully with sleep.

A much easier way to manage health

The findings point to something powerful: improving heart and metabolic health may not always require stricter diets, intense exercise routines, or fewer calories. 

For middle-aged and older adults at higher risk, simply aligning meals with sleep, extending the overnight fast by roughly three hours, and avoiding food close to bedtime may offer a practical, non-drug strategy.

“This sleep-aligned time-restricted eating approach represents a novel, accessible lifestyle intervention with promising potential for improving cardiometabolic function,” the study authors added.

In a modern culture where dinner keeps getting pushed later, and screens glow long past sunset, the message is surprisingly clear: the body runs on a schedule, and when we finally let it keep that schedule, the heart may respond in kind.

The study is published in the journal Arteriosclerosis, Thrombosis, and Vascular Biology.