A Periodic Diet that Mimics Fasting Promotes Multi-System Regeneration, Enhanced Cognitive Performance, and Healthspan

Summary

This Cell Metabolism paper from Valter Longo's USC group introduced the fasting-mimicking diet (FMD) — a 5-day periodic dietary protocol designed to deliver fasting's molecular benefits while keeping participants able to consume modest amounts of plant-based food. The paper has two parts. In aged mice, monthly FMD cycles for several months produced multi-system regeneration: hippocampal neurogenesis rose, IGF-1 dropped, PKA activity decreased, NeuroD1 expression increased, and cognitive performance improved on standard mouse cognition tests. In a 38-participant pilot human RCT, three monthly FMD cycles (each 5 days) produced reductions in body weight, body fat, blood pressure, fasting glucose, and IGF-1 without significant adverse events. The paper is foundational because it bridged rodent CR research and practical human protocol design — providing a structured, safe framework for delivering fasting benefits without continuous calorie restriction. Longo subsequently commercialized the protocol as ProLon, a packaged 5-day FMD product. The paper's data quality is solid but the commercial development complicates how it should be cited.