When You Eat Dinner Could Make a Bigger Difference for Your Heart Than You Think, New Study Says

It’s not uncommon to have a late-night dinner (or snack) right before hitting the hay. But according to a new study conducted by Northwestern University, cutting yourself off approximately three hours before bed can actually improve your cardiovascular health over time. “Among middle-aged and older adults who are at higher risk for cardiometabolic disease, extending the participants’ overnight fast by about two hours, dimming the lights, and not eating for three hours prior to bedtime improved measures of cardiovascular and metabolic health during sleep, as well as during the daytime,” the study reads. To identify the link between meal times and heart health, we dug deeper into the research.

The Link Between Meal Times and Heart Health

According to the study, our sleep-wake cycle—aka our circadian rhythm—is directly related to our heart and metabolic health. When we eat food, our body establishes a gastrointestinal transit time, which allows the body to digest, break down, and empty out the food we eat while absorbing its essential nutrients. So when we’re able to time our eating habits with our natural sleep-wake cycle, the systems in our body can work more efficiently to regulate cardiovascular and metabolic processes.

“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,” explains Dr. Phyllis Zee, chief of sleep medicine at Feinberg School of Medicine at Northwestern University. In previous studies, researchers have found that only 6.8% of U.S. adults had optimal cardiovascular health, linking poor cardiovascular health to chronic conditions such as type 2 diabetes, fatty liver disease, and cardiovascular diseases. Rather than promoting calorie-restricted diets—which can often lead to disordered eating—the study encourages sleep-aligned fasting to promote better rest, and as a result, improved cardiovascular health.

It’s especially important for those in middle and older age groups to practice sleep-aligned habits, as these demographics experience a higher risk for cardiometabolic disease. 

The Study’s Findings

During the study's seven-week-long trial, the researchers found that people who finished eating at least three hours before bed saw significant improvements in health markers compared to those who didn’t. The benefits included improved blood pressure and heart rate, decreasing by 3.5% and 5%, respectively. During the day, the participants experienced better daytime blood-sugar levels, suggesting that sleep-aligned fasting can actually regulate blood sugar and insulin output. 

In addition to eating habits, researchers encouraged participants to dim the lights in their room around the same time that they stopped eating. This encouraged the body’s natural melatonin production, allowing them to achieve better quality sleepand wake up feeling more energized.