[4] While there, he observed that his relatives in the United States were genetically similar to his family back home, but many of them were suffering from diabetes and cardiovascular disease due to diets rich in fat, meat, and sugar.

[1][3] To pay for his tuition, he worked at a gas station, repaired roofs, sold water filtration equipment, and joined the army as a reserve tank driver, narrowly avoiding deployment to combat during the 1991 Gulf War.

[1] During his second year of music, Longo was selected to direct the university's marching band—an assignment he considered humiliating for someone aspiring to be a rock star.

[6][11] Valter Longo is the Edna M. Jones Professor of Gerontology and Biological Sciences, as well as the director of the Longevity Institute at the Leonard Davis School of Gerontology at the University of Southern California,[12] and the Longevity and Cancer Program at the IFOM Institute of Molecular Oncology in Milan, Italy.

[24] Longo stated that the purpose of creating FMD was not to promote weight loss but to help end the global medical culture centered on pill consumption.

[26][27] MIT Technology Review reported that while ProLon was a commercial success, Longo was concerned about its potential impact on his scientific reputation.

In 2017, after a series of articles about the product—one of which described him as sounding like a "snake oil salesman"—he announced that he would no longer accept consulting fees and would donate his company shares to charity.