Most of us don’t just want to live longer. We want stay healthier at the same time — an extra 20-30 years lying in a sickbed sounds terrible.

Valter Longo, the director of the Longevity Institute at the University of Southern California, believes that by eating in a specific way, people might be able to live past 100 without developing debilitating diseases.

There’s solid evidence that suggests periodic fasting could prolong lifespan and prevent disease. Longo has designed a diet that he says provides the benefits of fasting while still letting people eat normally most of the time.