Overview
- Researchers randomized 39 overweight or obese adults ages 36–75 to an extended overnight fast of 13–16 hours ending at least three hours before sleep versus a usual 11–13 hour fast for about eight weeks.
- Both groups dimmed lights three hours before bedtime to support melatonin onset, anchoring the fasting window to sleep to align with circadian rhythms.
- Participants who stopped eating at least three hours before bed showed a roughly 5% nighttime heart rate drop and a 3.5% blood pressure dip, with healthier day–night heart rate patterns.
- The intervention group also demonstrated better daytime glucose handling, with more efficient insulin response, despite no significant changes in BMI or waist circumference.
- Adherence approached 90%, yet the sample was small, short in duration, and predominantly female, and investigators plan larger multi-center studies, including tests in people with hypertension or diabetes.