Obesity and aging have emerged as significant global public health concerns. Notably, the issue of aging is especially pronounced in China. However, there is relatively little research evidence regarding the disease burden of obesity in the elderly population, which needs to be addressed urgently.

To analyze the disease burden of elderly obesity population globally and in China from 1990 to 2021, and to predict future trends aiming to provide scientific evidence for the formulation of relevant public health prevention and control policies and healthcare decision-making.

Data on "high body-mass index" related to mortality and disability-adjusted life years (DALYs) for populations aged ≥60 in the global, China, and five sociodemographic index (SDI) regions were obtained from the Global Burden of Disease 2021 database. Joinpoint regression analysis was conducted to evaluate the trends of age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) over time, and results were reported as average annual percent change (AAPC) and corresponding 95%CI. A three-factor decomposition analysis was used to evaluate the relative impact of aging, population growth, and epidemiological changes on the disease burden. Additionally, a Bayesian age-period-cohort (BAPC) model was utilized to forecast mortality and DALYs trends from 2022 to 2035.

In 2021, the number of obesity-related deaths among elderly populations was 2 880 400 globally and 467 000 cases in China, representing increases of 161.26% and 359.19%, respectively, compared to 1990. Corresponding DALYs number reached 71 193 400 person-years globally and 11 763 600 person-years in China, with increases of 171.50% and 344.80%. Globally, the ASMR for obesity in the total elderly population and elderly males showed an overall upward trend from 1990 to 2021, with AAPC of 0.22% (95%CI=0.08%-0.36%, P=0.002) and 0.43% (95%CI=0.31%-0.55%, P<0.001), respectively. In China, the ASMR for obesity in the total elderly population, elderly females, and elderly males also showed an overall upward trend from 1990 to 2021, with AAPC of 1.19% (95%CI=0.97%-1.40%, P<0.001), 1.01% (95%CI=0.80%-1.23%, P<0.001), and 1.47% (95%CI=1.16%-1.77%, P<0.001), respectively. From 1990 to 2021, the global ASDR for obesity in the total elderly population, elderly females, and elderly males showed an overall upward trend, with AAPC of 0.53% (95%CI=0.44%-0.62%, P<0.001), 0.43% (95%CI=0.33%-0.54%, P<0.001), and 0.69% (95%CI=0.60%-0.79%, P<0.001), respectively. In China, the ASDR for obesity in the total elderly population, elderly females, and elderly males also showed an overall upward trend from 1990 to 2021, with AAPC of 1.45% (95%CI=1.32%-1.58%, P<0.001), 1.34% (95%CI=1.21%-1.47%, P<0.001), and 1.60% (95%CI=1.41%-1.79%, P<0.001), respectively. Furthermore, in 2021, the numbers of obesity-related mortality and DALYs among the elderly in the five SDI regions also rose to varying degrees compared to 1990. The 60-64 years age group accounted for the highest DALYs burden globally (16 500 500 person-years, 23.18%), while in China, the highest DALYs burden was observed in the 65-69 age group (2 930 200 person-years, 24.91%). Decomposition analysis identified population growth as the primary driver of the increased obesity-related disease burden across all regions. Forecasting models suggested that by 2035, the numbers of obesity-related deaths and DALYs among the global elderly population will increase by 66.33% and 71.93%, respectively, while in China, they are projected to rise by 151.17% and 135.03%.

The disease burden of obesity among the elderly remains substantial both globally and in China, and is expected to escalate in the future. Targeted efforts to enhance public health awareness, promote healthy aging and lifestyles, and appropriately utilize medical and surgical interventions can be necessary to mitigate the growing burden of obesity in elderly population.