Several aspects of energy dynamics, such as energy expenditure and caloric intake, are known to affect the aging process. In this article we therefore model the aging process within a mathematical framework describing the energy dynamics of an organism. The resulting model comprises food intake, body growth and survival. The equation for the mortality rate accounts for food consumption and is suited to describe caloric restriction data. For non-growing animals, the expression for the mortality rate reduces to the well-known Gompertz equation. We successfully applied our model to growth and survival data on mice exposed to different food levels.