

In the general population, the relationship between BMI and mortality is U-shaped ( 1) with excess mortality seen at BMI <22.5 kg/m 2 compared with 22.5–25 kg/m 2.

This may be due to limited power, as those studies describing no association all included <1,000 individuals ( 7– 10) and limitations of the analytical approaches.

However, the findings in patients with type 2 diabetes mellitus (T2DM) have been variable, with some studies reporting an increase in all-cause mortality with increasing body mass ( 4– 6), but many studies finding no relationship ( 7– 10) or a decrease in mortality with higher BMI ( 11). Compared with normal weight, obesity is associated with increased all-cause mortality in the general population, as well as increased cardiovascular and cancer mortality (excluding smoking-related cancers) ( 1– 3).
