Overweight BMI Does Not Necessarily Mean Higher Mortality Risk

WEDNESDAY, July 5, 2023 (HealthDay News) -- Overweight body mass index (BMI) is not necessarily associated with increased mortality risk, especially among older adults, although all-cause mortality is increased for those with BMI ≥30 kg/m², according to a study published online July 5 in PLOS ONE.

Aayush Visaria, M.D., and Soko Setoguchi, M.D., Dr.P.H., from the Rutgers Institute for Health in New Brunswick, New Jersey, conducted a retrospective cohort study of U.S. adults from the 1999 to 2018 National Health Interview Study to examine the association between BMI and mortality. The study sample included 554,332 adults who were followed for a median of nine years and maximum of 20 years.

During follow-up, there were 75,807 deaths recorded. The researchers found that across a wide range of BMI categories, the risk for all-cause mortality was similar, with adjusted hazard ratios of 0.95 and 0.93 for BMI of 25.0 to 27.4 kg/m² and 27.5 to 29.9 kg/m², respectively, versus 22.5 to 24.9 kg/m². After restriction to healthy never smokers and exclusion of individuals who died within the first two years of follow-up, these results persisted. For BMI ≥30 kg/m², a 21 to 108 percent increased mortality risk was seen. No significant increase in mortality was seen between BMI of 22.5 and 34.9 kg/m² among older adults, with the lack of increase restricted to the BMI range of 22.5 to 27.4 kg/m² for younger adults.

"Our findings suggest that BMI in the overweight range is generally not associated with increased risk of all-cause mortality," the authors write.

Abstract/Full Text