Fasting has long been hailed as an effective way to lose weight, improve the immune system, and boost brain function. But not everyone can tolerate going long periods without food.

But now scientists have developed a five-day, once-a-month diet that mimics fasting — and is safe and easier to follow, the Washington Post reports.

A study of the so-called "Fasting Mimicking Diet,” published in the journal Cell Metabolism and funded by the National Institute on Aging, found that individuals who intermittently fasted for three months had reduced risk factors for aging, cancer, diabetes, and cardiovascular disease.

While the number of study participants was small — only 19 tried the diet — the results are so promising that the University of Southern California researcher who helped develop the regimen is seeking 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 Valter D. Longo, who studies longevity. "It's not a typical diet because it isn't something you need to stay on."

For 25 days out of the month, dieters eat as they normally would. 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.

In the study, participants consumed a lot of vegetable soup, kale crackers, and chamomile tea. The participants in the study experienced decreased risk factors and biomarkers for disease with no major adverse side effects.