Does eating at night mess up your sleep and stress hormones?
The Window Matters: A Systematic Review of Time Restricted Eating Strategies in Relation to Cortisol and Melatonin Secretion
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Melatonin dropped in every single Ramadan study, even when sleep patterns were unchanged.
Most assume melatonin drops because people sleep later—but this study shows nighttime eating alone suppresses it, regardless of sleep timing.
Practical Takeaways
If you fast at night, try to eat your last meal before 8 PM and avoid heavy meals after 10 PM to reduce nighttime cortisol spikes.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Melatonin dropped in every single Ramadan study, even when sleep patterns were unchanged.
Most assume melatonin drops because people sleep later—but this study shows nighttime eating alone suppresses it, regardless of sleep timing.
Practical Takeaways
If you fast at night, try to eat your last meal before 8 PM and avoid heavy meals after 10 PM to reduce nighttime cortisol spikes.
Publication
Journal
Nutrients
Year
2021
Authors
S. Chawla, S. Beretoulis, A. Deere, D. Radenkovic
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During Ramadan fasting, melatonin levels tend to be lower at night, even when the body's daily rhythm is maintained. This may be due to eating at night and could be linked to worse sleep and changes in blood sugar control.
Studies on time-restricted eating outside of Ramadan show mixed results on cortisol levels: some report decreases, some show no change, and others report increases, with no clear relationship to when eating occurs during the day.
During Ramadan fasting, when eating is limited to nighttime hours, levels of the sleep hormone melatonin decrease at night, and the daily pattern of the stress hormone cortisol shifts—rising in the evening and falling in the morning—which may affect sleep and metabolic processes.
People who fast every morning over a long period show a less pronounced daily rhythm in cortisol levels and are more likely to have insulin resistance and metabolic issues.
When people skip dinner during time-restricted eating, evening cortisol levels tend to be lower; when they skip breakfast, morning cortisol levels tend to be lower. This suggests that when meals are eaten during the day affects the natural daily pattern of cortisol, potentially reflecting changes in stress hormone regulation.