Valter Longo

Valter Longo, a University of Southern California cell biologist, studies the benefits of fasting.

(Dietmar Quistorf)

Doctors know the best way for us to age well and keep disease at bay. It involves getting plenty of exercise and eating "heart-healthful" foods like salmon. Good genes and sunscreen really help, too.

Now researchers believe they may have stumbled upon an even better approach to a long, healthy existence. Fasting in regimented blocks of time could dramatically extend your life, suggests a study published last year in Cell Metabolism. It's called the Fasting Mimicking Diet, and the Washington Post reported that Valter Longo, one of the study's authors, "is already talking about trying to get approval from the Food and Drug Administration so that it can be recommended for patients."

"It's about reprogramming the body so it enters a slower aging mode, but also rejuvenating it," said Longo, a University of Southern California cell biologist. "It's not a typical diet because it isn't something you need to stay on."

BBC correspondent Peter Bowes, for one, is a believer. He participated in the USC clinical trial, which means he reduced his calories "by up to two-thirds, over five consecutive days, once a month for three months," he wrote this week on the website Quartz. "The rest of the time I ate normally, without restrictions."

Here's how The Post summarized the diet: "For 25 days out of the month, dieters can eat as they normally would -- the good, bad and in-between. Then for day one of the diet, they would eat 1,090 calories: 10 percent protein, 56 percent fat and 34 percent carbohydrates. For days two through five, 725 calories: 9 percent protein, 44 percent fat, 47 percent carbohydrates."

This regimen, Longo says, could turn us -- or, more likely, the next generation -- by far into the healthiest, longest-living humans ever. If, that is, the diet truly does work, which is what Longo is trying to nail down.

"This approach certainly leads to short-term weight loss," Bowes wrote. "But researchers prefer to see it as an investment in the future. Fasting this way could, they say, start a regenerative process that will lead to improved health and longer life. If the theory stands, I could enjoy a lower risk of cancer, a strengthened immune system, improved cognitive ability and little to no chance of contracting diabetes. The science is based on years of experimentation with yeast, worms, flies, mice -- and studies of Ecuadorians with a [rare] form of dwarfism."

It was the Ecuadorian dwarves who led medical science down this path, Bowes wrote. Their condition, researchers found, shuts off production of a growth hormone known as insulin-like growth factor-1. IGF-1 drives cell growth and division, so what happens when someone doesn't produce it? He or she probably won't get cancer, for one thing.

It's more complicated than that, of course, but that's the gist of it. (Read Bowes' in-depth essay.) And that's where the Fasting Mimicking Diet comes in. In short, fasting causes meaningful changes in our bodies -- and a key one is that levels of IGF-1 fall off a cliff. The Fasting Mimicking Diet seeks to find the sweet spot that brings the benefits of fasting -- long life, no cancer or diabetes -- without the serious negatives of food deprivation.

To be clear, this isn't something you should try on your own. The study participants ate special food packages called "ProLon" during their fasting periods. ProLon is not available at your local grocery or anywhere else.

Not yet, anyway.

-- Douglas Perry