Weight Loss from Maximum body weight and mortality: The Third NHIS Linked Mortality File

Obesity is an important risk factor for mortality, but it is unclear if weight loss for overweight persons is beneficial. This paper explores the relationship between weight loss from maximum body weight, body mass index (BMI), and mortality using the third National Health and Nutrition Examination Survey (NHANES III) Linked Mortality File. The NHANES III is a nationally representative sample of the civilian noninstitutionalized U.S. population; the Linked Mortality File is a passive followup through 2000 of the NHANES III participants. This study includes 6,143 whites, blacks, and Mexican-Americans aged 50 years and older at baseline (1988-1994). Weight loss was calculated as the difference between self-reported maximum lifetime body weight and body weight at baseline. For the analysis, weight loss was categorized as <5%, 5% to <10%, and >10%; BMI at maximum weight was categorized as <25.0, 25.0-29.9, >30.0. The relationship between weight loss and mortality was explored for each BMI category using Cox models in SUDAAN adjusted for various demographic and risk variables.

Weight loss of 15% or more from maximum body weight is strongly associated with increased risk of death among women and men aged 50 years and over regardless of maximum BMI. The limitations of this study and a comparison of these results with those from an earlier study that used data from the First NHANES will be discussed.