Hazard of obesity--the Norwegian experience.

Ten years' follow-up of mortality of 1.7 million persons aged 15 years or more with measured body weight and height demonstrates a consistent correlation between body mass index and mortality. The risk function is an asymmetrical U-function. This shape makes the determination of an optimum very uncertain. The two tails in the distribution of the body mass index show marked differences as to the causes of death: the lower tail is characterized by tuberculosis, lung cancer, obstructive lung diseases, and the upper tail by cerebrovascular and cardiovascular diseases, diabetes and (for males) colon cancer.