Another take on recent human calorie restriction (CR) research arrives via EurekAlert: "both calorie restriction and endurance exercise protect [mice and rats] against many chronic diseases including obesity, diabetes, cardiovascular disease and some types of cancer. However, the research has shown that only CR increases the animals' maximum lifespan by up to 50 percent. These animal studies suggest that leanness is a key factor in the prevention of age-associated disease, but reducing caloric intake is needed to slow down aging. ... [this human study] suggests that CR has some specific anti-aging effects that are due to lower energy intake, rather than to leanness ... Primary aging determines maximal length of life. Secondary aging, on the other hand, refers to diseases that can keep a person or an animal from reaching that expected lifespan. ... By slowing primary aging, CR may increase maximal lifespan." But don't skip the exercise - add both exercise and CR to your lifestyle and reap the benefits.