Longer Daytime Fasting may Increase Risk of Same-Day Headaches in Migraine Patients, suggests research

A study presented at American Headache Society Annual Scientific Meeting; June 19-22, 2025; Minneapolis has revealed that fasting for 5 to 6 hours increased the odds of a same-day headache by 49% in adults with episodic migraine, when compared to those fasting for only 1 to 2 hours. This research cautioned that altering eating habits based on these findings may be premature.

The findings come from a secondary analysis of a prospective, 90-day observational study involving 42 adults with episodic migraine, who were asked to complete electronic headache diaries 3 times daily. On average, participants experienced 9.4 headache days per month and tracked their meal and snack timing between 5 a.m. and 8 p.m. via evening diary entries.

This research defined the "maximum daytime fasting interval" as the longest time between meals or snacks during waking hours. The study by Slavin and team aimed to evaluate whether this interval influenced the same-day risk of experiencing a headache.

The analysis showed that when participants fasted for 5–6 hours during the day, they had 49% higher odds of experiencing a headache on the same day compared to days when they fasted for only 1–2 hours. This association remained statistically significant, with an odds ratio (OR) of 1.49 (95% confidence interval: 1.05–2.12, p = 0.028).

Interestingly, no other fasting intervals—whether shorter or longer than 5–6 hours—were significantly associated with same-day headache occurrence. This suggests a potential "trigger zone" within that time frame, highlighting a specific fasting duration that may be particularly relevant for people with migraine.

The participant demographics showed a majority of the sample were women (83.3%), White (76.2%), and non-Hispanic (78.6%), with an average age of 37.2 years. Across the entire study, 98% of completed evening diary entries included reliable data on food intake, strengthening the validity of the analysis.

The observed fasting intervals that triggered headaches (5–6 hours) are well within typical eating patterns among U.S. adults, and significantly shorter than the 8-hour threshold required for a diagnosis of “headache attributed to fasting” under the International Classification of Headache Disorders (ICHD-3).

Overall, this research cautioned that the relationship between fasting and migraine could be bidirectional—meaning that headache onset might also delay eating. Yet, the data suggest that people with episodic migraine may benefit from eating more frequently, potentially keeping daytime fasting under five hours. Further studies are needed to explore whether proactively shortening fasting periods can improve headache outcomes over time. For now, maintaining regular meal schedules could be a simple and effective strategy for migraine prevention.

Source:

Slavin, M., Ozmeral, A., Greenfield, M., & Seng, E.K. American headache society 67th annual scientific meeting June 19-22, 2025 Minneapolis, Minnesota: Late breaking scientific abstracts for headache. P-358. (2025). Headache. https://doi.org/10.1111/head.14987