Via Forbes, another study attempting to tease out the mechanisms by which calorie restriction affects metabolism and health: "Lowering the core body temperature of mice let them live an average of 15 percent longer ... It was known in animals that calorie restriction is associated with reduction of the core body temperature. It was not known if temperature reduction was a consequence of calorie restriction or also contributed to its beneficial effects. ... The new study [shows] the latter to be true because the cooled-down mice lived longer even when they were allowed to eat as much as they wanted ... lowering body temperature does not prolong life span. It allows more mice to reach old age. ... Calorie restriction, by contrast, does extend life span."