The Calorie Restriction Theory postulates that a diet providing optimal nutrition with a minimum of calories will confer the maximum life span to an individual.

This theory, put forward by Dr. Roy Walford, gerontologist at UCLA Medical School, was confirmed by years of scientific experiments with animals.

In a less scientific way we see this same result corroborated in people all around us.

Those who overeat and who are considerably overweight appear to have more difficulties with their health. Statistically this is borne out as well: heavy, overweight individuals are more prone to illness and disease, especially cardiovascular problems, and face a lower life expectancy than someone who is fit.

Severe calorie restriction is difficult to follow and has been found ineffective as an approach to weight loss.

An average North American eats 2100 to 2600 calories per day and should cut down to 1500 per day to achieve optimum intake.

While the level of health will increase, to date results have not shown age reversal to be substantial in humans when calories are restricted.