Severely restricting calorie consumption can drastically reduce the risk of developing diabetes, a heart attack or a stroke, according to a study published on Monday.

Researchers at Washington University School of Medicine in St. Louis, Missouri, found that the people in their 50s or 60s who adopted a low-calorie diet experienced the same risks as people who were decades younger.

"It's very clear from these findings that calorie restriction has a powerful, protective effect against diseases associated with aging," said John Holloszy, a professor of medicine who led the study published in the Proceedings of the National Academy of Sciences.

"We don't know how long each individual actually will end up living, but they certainly have a much longer life expectancy than average because they're most likely not going to die from a heart attack, stroke or diabetes," Holloszy said.

Eighteen people ages 35 to 82 who participated in the study were under a low-calorie diet for three to 15 years. They were compared to a similar group of 18 people who had a typical "Western" diet.

The low-calorie diet group consumed 1100 to 1950 calories per day, depending on individuals' height, weight and gender. Of the calories, 26 percent consisted of protein, 28 percent fat and 46 percent complex carbohydrates.

The Western diet group ate between 1975 and 3550 calories a day, and consisted of 18 percent protein, 32 percent fat and 50 percent carbohydrates, including starches.