When it comes to heart health, timing when you eat may matter just as much as what you eat.

A new study from researchers at Northwestern University found that eating dinner at least three hours before bedtime may improve cardiovascular health over time.

Scientists reported that “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,” according to Real Simple.

Researchers say the benefits may be linked to the body’s circadian rhythm — the internal clock that regulates sleep and wake cycles. The digestive system is closely connected to this rhythm. Allowing enough time to digest food before sleep helps the body process nutrients more efficiently and supports healthy metabolic and cardiovascular function.

This sleep-aligned fasting may also improve blood sugar control.

Poor cardiovascular health is associated with a higher risk of chronic conditions such as Type 2 diabetes, fatty liver disease, and heart disease. Researchers note that only about 6.8% of American adults currently meet the criteria for optimal cardiovascular health.

In the seven-week study, participants who finished eating at least three hours before bedtime experienced measurable improvements. Their blood pressure dropped by about 3.5%, while heart rate decreased by roughly 5%.

Participants also showed better daytime blood sugar control, suggesting that sleep-aligned fasting may help regulate both glucose levels and insulin production.

The takeaway: finishing dinner earlier in the evening may provide meaningful benefits for heart and metabolic health. Allowing the body time to digest before sleep helps prevent late-night spikes in blood sugar and cholesterol, while supporting the body’s natural circadian rhythm and overall cardiovascular function.