Summary <p>This study examined the global burden of fractures, low bone mineral density (BMD), and high body mass index (BMI) across various age groups, periods, and cohorts, revealing significant health inequalities and the need for targeted interventions.</p> Purpose <p>To analyze globally long-term trends in fractures, low BMD, and high BMI, and to examine effects of age, cohort, period, and health inequalities.</p> Methods <p>The estimated annual percentage change (EAPC) in age-standardized rates (ASR) of prevalence, Disability-Adjusted Life Years (DALYs) or Years Lived with Disability (YLDs) were utilized to estimate the trends, and health inequality indices were applied to assess the socioeconomic disparities, in 204 countries or territories from 1990 to 2021. The age-period-cohort model was used to assess the independent effects of age, period, and cohort.</p> Results <p>From 1990 to 2021, fracture prevalence and the DALYs attributable to low BMD generally declined (EAPC for fracture prevalence: -0.53%; EAPC for DALYs attributable to low BMD: -0.90%), while the DALYs attributable to high BMI increased (EAPC: 0.66%). The disease burden attributable to fractures, low BMD, and high BMI generally increased with age. Globally, there was a pattern of rising and then declining risk of fractures and low BMD in successively younger birth cohorts, alongside an increasing risk of high BMI. Significant Socio-demographic Index (SDI)-related inequalities in burdens of fractures, low BMD, and high BMI were observed, with inequalities quantified by the slope index of inequality (SII) in 2021 showing values of 267, -53, and -119, respectively.</p> Conclusions <p>Global trends in burden of fractures, low BMD, and high BMI varied across different age groups, periods, cohorts, and varied SDI regions.</p>