The benefits of eating fewer calories may go far beyond losing weight and can boost your sex life and extend your life.

Three decades of animal studies have found that eating fewer calories can extend lifespan and reduce the risk of chronic diseases and even some cancers. And some, though not all, of these benefits are starting to be seen in men and women taking part in clinical trials.

For instance, in moderately overweight people, restricting calories by 25 percent over two years improved blood pressure and cholesterol counts, and resulted in weight loss. Participants also had a 47 percent drop in levels of C-reactive protein, a marker of inflammation linked to heart disease.

A second study done by researchers from the same institutions focused on calorie restriction to see if it affected other important aspects of life like mood, sleep and sex.

Not surprisingly, the participants who ate 25 percent fewer calories lost weight -- about 15 pounds on average. What was surprising? Their mood significantly improved, and they experienced more vigor, less tension and better overall health. They also had an improved sex drive, better relationships and even greater sleep quality.

Keep in mind that safe calorie restriction means reducing intake without depriving yourself of essential nutrients. So every calorie has to be carefully chosen. This is especially important if you're already at a healthy weight without any fat stores to burn. Make sure your first calories go toward nutrient-rich foods, like vegetables, fruit, whole grains, legumes and lean protein.

If you'd like to explore calorie restriction, there are many ways to ease into it, such as doing it just two days a week.