USC study: Fast-like diet may lower biological age, reduce disease risk

As its name suggests, the FMD aims to mirror the effects of a water-only fast. Each cycle involves five days following the plant-based diet—high in unsaturated fats and low in protein, calories, and carbohydrates—and 25 days of your typical eating habits. In a study led by researchers at the University of Southern California Leonard Davis School of Gerontology, people who completed three monthly FMD cycles showed a 2 ½-year decrease in median biological age, independent of weight loss. The findings were published this month in the journal Nature Communications.

“[FMD] is making the system younger and by making it younger, making it more functional,” senior author Valter Longo, Ph.D., director of the USC Longevity Institute, tells Fortune. “It’s really repairing the problem from the source, rather than just putting a Band-Aid downstream of it.”

What is the fasting-mimicking diet?

Longo says he developed the FMD some 20 years ago as a standardized diet for people with cancer that could be used in clinical trials. Now marketed as ProLon, the five-day program sells proprietary FMD kits online for $195 ($175 for subscribers). Each contains:

• Energy bars
• Energy drinks
• Herbal teas
• Multivitamin supplements
• Snacks
• Vegetable-based soups

Study participants strictly adhered to these prepackaged items. Longo recommends following three FMD cycles for a total of 15 diet days, which he says is more achievable for people who may have difficulty changing their eating habits long term.

“It doesn’t require lifestyle changes,” he says. “You can look at it more as a medicine. It comes in a box, lasts five…