Valter Longo

Valter Longo is an Italian-American biologist who directs the USC Longevity Institute in Los Angeles and a longevity and cancer program at the IFOM institute in Milan. He studies how diet and fasting affect aging, from yeast and mice to human trials.

Best known for

The fasting-mimicking diet, a five-day, low-calorie, low-protein plant based plan, and his book The Longevity Diet (2018).

Approach

Mostly plants with fish two or three times a week, plenty of olive oil and some nuts, protein kept low but adequate until about 65, a 12-hour daily eating window, and a few fasting-mimicking cycles a year. He sits next to the plant based movement rather than inside its low-fat school.

Main talking points

• In his studies, high protein intake in midlife, especially animal protein, was linked to higher cancer risk; older adults need more protein.
• Protein raises IGF-1, a growth hormone he links to aging and cancer.
• Eat within about 12 hours of the day and stop three or four hours before bed.
• His trials report that periodic fasting-mimicking cycles improve risk markers such as blood pressure and blood sugar.

Books

• Fasting Cancer Fasting Cancer2025
• The Longevity Diet2018