scientist with a hamburger collaged next to him
Valter Longo is a biologist who studies healthy aging.
  • Valter Longo moved from Italy to the US as a teenager and quickly saw his cholesterol skyrocket.
  • He's since developed an extremely popular 5-day fasting diet.
  • He says it needn't be hard to eat healthy — filling your cart with frozen produce is his first tip.

Valter Longo was just 16 when he landed in the US, ready to rock. He loved the bold electric sound of Jimi Hendrix, and had arrived in America to pour his heart and soul into studying jazz guitar.

Food was an afterthought. Longo went with what was easiest, consuming all the same things his American relatives and friends were eating.

"I didn't know any better," he told Business Insider.