Abstaining from food at least three hours before bedtime may offer substantial benefits for heart health. A recent Northwestern University study found that extending an overnight fast, coupled with dimming lights in the evening, can improve cardiovascular and metabolic well-being, particularly in middle-aged and older adults who are at higher risk for cardiometabolic diseases.
The eight-week study, published in Arteriosclerosis, Thrombosis and Vascular Biology, involved 39 overweight and obese participants. Those who adopted an extended overnight fasting intervention of 13 to 16 hours, while also dimming lights three hours before sleep, demonstrated meaningful improvements compared to those with habitual fasting routines. Key findings included a 3.5% drop in blood pressure and a 5% reduction in heart rate, along with a more natural decline in these measures during sleep - a critical indicator of cardiovascular health.
Participants also exhibited better daytime blood sugar control, indicating a more efficient pancreatic response to glucose. Researchers noted that this simple adjustment in meal timing can enhance the coordination between the heart, metabolism, and sleep cycles, thereby protecting cardiovascular health.
Experts emphasize that the three-hour pre-sleep fasting window is critical as it aligns with the body's natural transition to sleep, a period when eating can disrupt metabolism. The high adherence rate observed in the study suggests this approach is both feasible and sustainable for improving cardiometabolic health. This research adds to a growing body of evidence linking sleep and circadian rhythms to heart health, with organizations like the American Heart Association now recognizing healthy sleep as a pillar of cardiovascular well-being.