WASHINGTON — Doctors say fasting isn’t the best way to lose weight because it’s risky.

Still, the practice has been around for thousands of years. Fasting has a religious tradition and is used as a form of protest.

Now, scientists are reporting some remarkable health benefits from a diet that mimics fasting. 

Scientists at the University of Southern California sharply reduced the calorie, protein, carbohydrates and fat for a group of reasonably healthy adults. The study lasted five days a month over a three-month period.

Scientists say the fasting mimicking diet produced beneficial changes in risk factors of age related diseases.

In the journal Cell Metabolism, scientists report that the diet cut risk factors for diabetes, cardiovascular disease and cancer.

Test subjects consumed up to 54 percent fewer calories than a normal diet during the five-day trial.

In mice, the scientists found multi-system regeneration, improved metabolism and cognitive function, and decreased bone loss from the fasting mimicking diet.

The scientists say diet and calorie level are key factors affecting aging and age-related diseases.