Avoiding food late at night and extending the overnight fasting period may improve cardiovascular and metabolic health, according to a recent study published in Arteriosclerosis, Thrombosis, and Vascular Biology1.
The research examined whether aligning meal timing with sleep cycles could influence heart function, blood pressure, and blood sugar regulation.
The findings suggest that finishing meals at least three hours before bedtime and extending the overnight fasting window may improve several markers linked to cardiometabolic health.
The study, titled “Sleep-Aligned Extended Overnight Fasting Improves Nighttime and Daytime Cardiometabolic Function,” evaluated whether a simple change in eating timing could improve cardiovascular and metabolic markers.
Researchers conducted a clinical trial involving 39 adults aged 36 to 75 years who were overweight or obese. Participants were assigned to one of two groups:
Extended overnight fasting group: fasting for about 13–16 hours, with the last meal at least three hours before sleep
Control group: maintaining their typical overnight fasting window of 11–13 hours
The intervention lasted 7.5 weeks. Both groups also dimmed lights three hours before bedtime to align with normal sleep patterns.
Participants who followed the extended overnight fasting schedule showed improvements in several cardiovascular indicators.
Key findings included:
Nighttime blood pressure decreased by approximately 3.5%
Nighttime heart rate decreased by about 5%
Improved day–night rhythm of cardiovascular activity
Normally, blood pressure and heart rate decrease during sleep in a process known as “nighttime dipping.” A stronger dipping pattern is generally associated with better cardiovascular health.
Researchers observed that participants who avoided late-night meals showed more pronounced dipping patterns compared with those maintaining usual eating habits.
In addition to cardiovascular effects, the study reported improvements in metabolic markers.
Participants practicing extended overnight fasting showed:
Lower glucose levels during a glucose tolerance test
Improved insulin response
More efficient pancreatic function when processing glucose
These changes indicate improved daytime blood sugar regulation, which plays an important role in preventing metabolic conditions such as type 2 diabetes.
The researchers noted that meal timing may influence how the body coordinates metabolism with the circadian rhythm, the internal biological clock that regulates sleep, hormones, and energy use.
Eating late at night may interfere with this rhythm because the body begins preparing for rest during the evening. Hormonal changes, including increased melatonin levels, may make the body less efficient at processing food during this period.
Aligning eating patterns with sleep cycles may therefore help improve the coordination between:
cardiovascular function
metabolic processes
sleep-related autonomic activity
Importantly, participants in the study did not reduce calorie intake. The improvements were observed solely from changing when they ate, rather than altering diet composition or total energy consumption.
Researchers suggested that extending overnight fasting in alignment with sleep schedules may represent a practical lifestyle strategy for supporting cardiometabolic health.
However, the study authors also noted that further research with larger populations will be necessary to confirm these findings and explore long-term effects.
Reference
Grimaldi, Daniela, Kathryn J. Reid, Sabra M. Abbott, Kristen L. Knutson, and Phyllis C. Zee. “Sleep-Aligned Extended Overnight Fasting Improves Nighttime and Daytime Cardiometabolic Function.” Arteriosclerosis, Thrombosis, and Vascular Biology (2026). https://doi.org/10.1161/ATVBAHA.125.323355.
