For more than 50 years, life insurance companies have pointed out that greatly increased body weight is associated with an above-average death rate. In the course of investigating why this is so, researchers have developed a number of ways of judging whether people weigh more than they should for op¬timal health.

The two most important factors associated with the risk of developing several chronic diseases are (1) total body fat, most often estimated by the ratio of body weight to height, and (2) distribution of that fat, on the stomach or on the hips and legs.

Two terms are applied to people who weigh more than they should. "Overweight" indicates an excess amount of weight for a given height above some standard.

"Obese" indicates an ex¬cessively high amount of body fat compared to muscle and bone.