He also founded the company that sells the food for this treatment:

Longo is the founder of and has an ownership interest in L-Nutra; the company's food products are used in studies of the fasting-mimicking diet. Longo's interest in L-Nutra was disclosed and managed per USC's conflicts-of-interest policies. USC has an ownership interest in L-Nutra and the potential to receive royalty payments from L-Nutra. USC's financial interest in the company has been disclosed and managed under USC's institutional conflict of interest policies.