For many years, it has been known that when rats and mice are given a reduced amount of food, their life span is increased and they remain healthy and vigorous at advanced ages.

What is the reason for this change in the usual pattern of aging? The evidence is overwhelming that the life extension results from a slowing of aging processes. And the factor responsible is the decrease in caloric intake. The obvious question: How does this factor work? A good question - and the reason that research on the anti-aging action of caloric restriction is today one of the most studied research areas in...