Does intermittent fasting slow down metabolism?

No. Intermittent fasting does not slow down metabolism. Multiple studies, including those from NIH and Harvard, show that typical intermittent fasting protocols maintain or even increase resting metabolic rate.

Scientific evidence consistently indicates that intermittent fasting (IF) does not slow metabolism in healthy adults. Studies from the NIH, Harvard, and the Salk Institute reveal that standard IF regimens maintain or sometimes increase resting metabolic rate, and can activate beneficial metabolic pathways such as fat oxidation and AMPK signaling.

Short-term fasting has even been shown to boost metabolism by up to 14%, according to peer-reviewed sources like Healthline and PubMed. Adverse effects on metabolism are mainly observed in cases of prolonged or extreme fasting, not standard IF patterns like time-restricted eating or alternate-day fasting.

Any temporary reduction in metabolic rate from prolonged fasting is typically reversed when normal eating resumes. The overall scientific consensus is that typical intermittent fasting protocols do not slow metabolism and may confer metabolic benefits.

Read the full analysis

Did you know?

Vivid dreams most commonly occur during REM, the brain’s most wake-like sleep stage. Controlled studies show tomatoes actually reduce inflammation markers, not increase them. Late-day caffeine can steal ~45 minutes of sleep and cut deep sleep significantly.

Verify any claim

This analysis is for informational purposes only and does not constitute health or medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before making health-related decisions.