Projecting the macroeconomic burden of high body mass index related diseases in China: A Bayesian productivity‐adjusted life years approach based on global burden of diseases 2023

BACKGROUND: The burden attributable to body mass index (BMI) remains a major public health concern in China and imposes substantial socio-economic costs. METHODS: Data from the Global Burden of Disease Study 2023 and economic projections were integrated to estimate and project the burden among Chinese adults aged 20-64 years. A multi-method approach was utilised, including burden estimation, joinpoint regression for trend analysis, demographic decomposition, age-period-cohort (APC) modelling, and Bayesian age-period-cohort (BAPC) modelling for future projections. This study introduced and applied the B-PALY framework, which integrates the BAPC model with productivity-adjusted life years (PALYs), to systematically predict the productivity impact and macroeconomic burden associated with high BMI-related diseases. RESULTS: In 2023, high BMI-related diseases caused 118 511 deaths and 9.7 million disability-adjusted life years (DALYs), accounting for approximately 20% of all deaths and 25% of all DALYs among China's working-age population. From 1990 to 2023, the burden showed significant upward trends. Demographic decomposition identified population aging and growth as primary drivers, partially offset by epidemiological changes. APC analysis revealed an increasing disease burden with age and elevated DALY risks in recent birth cohorts. Projections indicated a substantial rise in the burden of diseases attributable to high BMI, in terms of absolute deaths and DALYs, through 2050. The B-PALY framework estimated that, in 2023 alone, these diseases imposed a macroeconomic burden of approximately 129.77 billion Intl$ (about 0.03% of China's 2023 GDP). Projected cumulative losses from 2023 to 2029 amount to Intl $1.14 trillion. CONCLUSION: High BMI-related diseases caused a substantial health and macroeconomic burden in China's working-age population, with rising trends projected to continue.