WEDNESDAY, Dec. 1 (HealthDay News) -- All-cause mortality is lowest for adults with a body mass index (BMI) of 20.0 to 24.9 kg/m², and the risk is more than doubled for those who are extremely obese, according to research published in the Dec. 1 issue of the New England Journal of Medicine.
Amy Berrington de Gonzalez, of the National Cancer Institute in Bethesda, Md., and colleagues used pooled data from 19 prospective studies of 1.46 million white adults with a median age of 58 to determine the relationship between BMI and all-cause mortality. The results were adjusted for age, physical activity, alcohol consumption, education, and marital status.
The relationship of BMI and all-cause mortality was represented by a J shaped curve, with higher mortality in both the underweight and overweight/obese groups. Using a BMI of 22.5 to 24.9 kg/m² as the reference category, the researchers found that hazard ratios of 1.13, 1.44, 1.88, and 2.51 were seen in those with a BMI of 25.0 to 29.9, 30.0 to 34.9, 35.0 to 39.9, and 40.0 to 49.9 kg/m², respectively. Hazard ratios were also increased in the underweight BMI categories (1.47 for a BMI of 15.0 to 18.4 kg/m² and 1.14 for a BMI of 18.5 to 19.9 kg/m²), but these were attenuated with a longer follow-up period. All-cause mortality was generally lowest in the 20.0 to 24.9 kg/m² BMI group.
"Our findings are broadly consistent with those of the Prospective Studies Collaboration, which showed an optimal BMI of 22.5 to 25.0 in analyses of all study participants and of 20.0 to 25.0 in analyses restricted to participants who never smoked," the authors write.
One of the authors disclosed receiving consulting fees from Iovate Health Sciences USA.
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