Fasting-mimicking diet (FMD)

The fasting-mimicking diet is a 5-day low-calorie, low-protein, plant-based regimen developed by Valter Longo's group that reproduces metabolic effects of water-only fasting—reduced IGF-1, glucose, and insulin; elevated ketones—while still providing some food. Pivotal trials used 3 cycles spaced one month apart and reported improvements in cardiometabolic risk markers and abdominal adiposity. Suggested benefits on biological age estimates rest on secondary analyses (Brandhorst et al. 2024, Nature Communications) and should be considered preliminary.