Trends in Obesity Prevalence among US Older Adults in the Last Two Years of Life, 1998–2018

Context: The prevalence of obesity has grown in the US over the decades. The temporal trends of body mass index categories in the last two years of life are poorly understood. Objectives: To describe the trends in body mass categories in the last two years of life over the past two decades controlling for other demographic changes. Methods: We performed a cross-sectional study of prospectively collected survey data from the nationally representative Health and Retirement Study (HRS) among decedents who died between 1998 and 2018. We categorized BMI into five categories and calculated the proportion of decedents with each BMI category during each four epochs (1998–2003, 2004–2008, 2009–2013, 2014–2018). We examined trends in regression models with survey wave groupings modeled as an orthogonal polynomial and adjusted for factors commonly associated with BMI: sex, age, race, ethnicity, education, and tobacco use. Results: The analytic cohort included 14,797 decedents. From 1998–2003 to 2014–2018 time periods, those categorized as having mild-to-moderate obesity in the last two years of life increased from 12.4% to 14.8% (linear trend P < 0.001), a 19% increase. Severe obesity increased from 1.9% to 4.3%, a 126% increase (linear trend P < 0.001). Underweight decreased from 9.9% to 5.9%, a 40% decrease (linear trend P < 0.001), adjusted for demographic factors. Adjusted quadratic temporal trends for BMI category were nonsignificant, except for in mild-to-moderate obesity. Conclusion: Severe obesity has increased greatly while underweight has decreased. As obesity increases in the final years of life, it is critical to assess how the existing and future palliative services and end of life care system address body size and weight.