Fact: Calorie restriction is proven to extend lifespan in animals.
Key Info: Caloric restriction retards aging, what has been observed, is less cell mutation and cell death.
The Data: Geneticists have now linked "cell death" to aging. Changes in the powerhouses of our cells, the mitochondria, appears to trigger cells to die and speed up the aging process. Inducing these changes, in a lab, leads to premature aging in mice, which live only about half as long as normal mice. It is believed slowing this process is one of the major mechanisms of how caloric restriction retards aging.
My Thoughts: One strategy to achieve a "caloric restriction" environment for would be to reduce and maintain bodyfat levels to better than excellent levels and do cardio exercise 5x per week. Eating small portions is essential to maintain low bodyfat levels.