Who Is Valter Longo?
Valter Longo is a professor of gerontology and biological sciences at the University of Southern California and the director of the USC Longevity Institute. Born in Italy, he received his PhD in biochemistry from UCLA, where he studied the role of proto-oncogenes in aging under Roy Walford, the pioneering caloric restriction researcher.
His laboratory studies the mechanisms of aging and age-related diseases using organisms ranging from baker's yeast to mice to humans, with a particular focus on how dietary interventions can extend healthy lifespan.
Key Scientific Contributions
Fasting Mimicking Diet (FMD) Longo's most significant practical contribution is the development of the Fasting Mimicking Diet — a 5-day, low-calorie, plant-based protocol (~800 kcal/day) designed to trigger the biological effects of extended fasting while providing enough nutrition to reduce the discomfort and risks associated with complete water fasting.
Clinical trials have shown FMD to:
- Reduce IGF-1 (a major driver of cellular aging and cancer)
- Activate stem cell regeneration in multiple organ systems
- Improve fasting glucose, blood pressure, and inflammatory markers
- Reduce visceral fat and trunk fat specifically
Longevity Genes and Pathways Longo's lab was among the first to identify that mutations in the IGF-1/insulin signaling pathway — in yeast, worms, flies, and mice — dramatically extend lifespan. He subsequently studied centenarian populations in Calabria, Italy, identifying IGF-1 receptor mutations associated with exceptional longevity in humans.
The 5 Pillars of Longevity Longo has synthesized his research and epidemiological studies into a practical framework: eating a primarily plant-based diet, time-restricted eating, periodic fasting (FMD), maintaining muscle mass with moderate protein, and combining these with purpose and social connection.
Why Follow Him
Valter Longo offers the strongest scientific case for periodic fasting as a longevity intervention — grounded in evolutionary biology, mechanistic cell biology, and human clinical trials. Unlike many longevity influencers, his protocols have been tested in randomized controlled trials and his findings are reproducible. For anyone exploring fasting, his work provides the rigorous foundation.