Mortality as a function of obesity and diabetes mellitus.

Mortality according to body mass index (weight/height2) was studied in 2197 Pima Indians aged 15-74 years, as part of the longitudinal study of diabetes begun in 1965 in the Gila River Indian Community of Arizona. The Pima Indians are a population with a high prevalence of obesity, and they have the highest known incidence of type II (non-insulin dependent) diabetes mellitus. Among males, mortality was greatest in those with a body mass index of at least 40 kg/m2, but obesity had little effect on mortality at body mass indices below 40 kg/m2. Age-specific death rates in women were not consistently related to obesity, although mortality in subjects with diabetes was higher than in those without. In men, diabetes had little effect on mortality. In this study, as in several other mortality studies, the lowest mortality rates were experienced by people with body weights well above those recommended as "desirable" by the Society of Actuaries in 1959. Thus, the applicability of the "desirable" weight standards in common use is questioned.