Background: Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease, is one of the most prevalent liver diseases globally, contributing to both economic and health-related challenges. We aimed to evaluate the global, regional, and national burden of MASLD from 1990 to 2023, quantify the contribution of identified modifiable risk factors, and project future prevalence up to the year 2050. Methods: Estimates of MASLD prevalence and disability-adjusted life-years (DALYs) were produced by age, sex, region, Socio-demographic Index (SDI), and Healthcare Access and Quality (HAQ) index across 204 countries and territories from 1990 to 2023 as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2023. The MASLD burden attributable to three risk factors (smoking, high BMI, and high fasting plasma glucose) was assessed as part of the GBD comparative risk assessment. As a secondary analysis, we used these estimates to forecast MASLD prevalence up to 2050 using fasting plasma glucose and mean BMI as predictors. Furthermore, to examine the relative contributions of population ageing, population growth, and changes in MASLD prevalence rate to the forecasted changes in case counts from 2023 to 2050, we conducted a decomposition analysis. Findings: In 2023, approximately 1·3 billion (95% uncertainty interval [UI] 1·2 to 1·4) individuals were estimated to be living with MASLD (ie, 16·1% of the global population), with an age-standardised prevalence rate of 14 429·3 (95% UI 13 268·3 to 15 990·6) per 100 000 population, representing a percentage increase of 142·7% (95% UI 139·2 to 146·7) in crude numbers from 1990 (0·5 billion [0·5 to 0·6]) and of 28·6% (27·8 to 29·5) in the rate (11 217·2 [10 276·8 to 12 467·0] per 100 000 in 1990). An estimated 3·6 million (2·8 to 4·5) total DALYs were attributable to MASLD worldwide in 2023, corresponding to an age-standardised DALY rate of 39·6 (31·2 to 49·9) per 100 000 population. Despite a 116·3% (93·3 to 139·4) increase in crude DALYs (from 1·7 million [1·3 to 2·1] in 1990), its age-standardised estimate remained consistent (1·8% [–8·6 to 12·8]) from 1990 (38·9 [30·1 to 49·8] per 100 000) to 2023. There was substantial variation in age-standardised estimates across regions. North Africa and the Middle East had the highest prevalence rate (29 246·1 [26 848·3 to 32 048·7] per 100 000) and Andean Latin America showed the highest DALY rate (152·3 [114·1 to 194·7] per 100 000). By contrast, the high-income Asia Pacific region had the lowest prevalence rate (8653·5 [7923·7 to 9592·8] per 100 000) and east Asia had the lowest DALY rate (16·3 [13·5 to 19·9] per 100 000) among all GBD regions. North Africa and the Middle East showed disproportionately higher prevalence rates relative to other regions with similar SDIs. Lower SDIs and HAQs were associated with higher age-standardised DALY rates. The age-standardised prevalence rate was consistently higher in males (15 616·4 [14 349·2 to 17 263·3] per 100 000 people in 2023) than in females (13 245·2 [12 132·0 to 14 692·6] per 100 000 people), and peaked at age 80–84 years in both sexes. The number of MASLD prevalent cases was the highest in younger adults, peaking at age 35–39 years for males and age 55–59 years for females. Among the risk factors for MASLD, high fasting plasma glucose presented the largest contribution to the age-standardised DALY rate of total MASLD in 2023 (2·2 [95% UI 1·6 to 3·1] per 100 000 people), followed by high BMI (1·4 [0·6 to 2·4] per 100 000 people) and smoking (1·0 [0·3 to 1·8] per 100 000 people). Our forecasting model estimates that 1·8 billion (95% UI 1·6 to 2·0) individuals are likely to have MASLD by 2050, representing a 42·0% increase from 2023. The age-standardised prevalence rate is expected to increase to 15 774·9 (95% UI 14 613·9 to 17 336·2) per 100 000 people in 2050, representing an average annual percentage change of 0·3% (95% UI 0·3–0·3). According to our decomposition analysis, this change will be primarily due to population growth, particularly in sub-Saharan Africa and North Africa and Middle East, and less by population ageing or epidemiological change. Interpretation: With a global prevalence of 16·1% and approximately 1·3 billion people already living with MASLD in 2023, the condition has and will continue to have substantial health and economic impacts worldwide. An inverse association between the HAQ Index and age-standardised DALY rates suggests that countries with lower health-care access and quality might be less well positioned to manage the growing MASLD burden, underscoring the need for strengthened health-system capacity in these settings. Funding: Gates Foundation.

Background Road injuries are a leading cause of mortality and morbidity worldwide. Years of international efforts have aimed to strengthen policy engagement, including the 2020 UN General Assembly's proclamation of the Second Decade of Action for Road Safety (2021–30), targeting a 50% reduction in road traffic deaths and serious injuries by 2030. The aim of this study is to provide estimates to monitor progress and identify intervention gaps. Methods As part of the Global Burden of Diseases, Injuries, and Risk Factors Study 2023, we estimated incidence, mortality, and morbidity of road injuries for 204 countries and territories from 1990 to 2023. Four road injury types and 47 nature-of-injury categories were examined. Morbidity and mortality data from clinical records, vital registration, and police reports were harmonised using meta-analytic techniques to ensure consistency and correct for systematic bias. Incidence was modelled with the meta-regression tool Disease Modelling-Meta-Regression version 2.1 and cause-specific mortality with the Cause of Death Ensemble model, both incorporating location-specific covariates to support interpolation. Years of life lived with disability (YLDs) were estimated from the prevalence and severity of the nature of road injury, and years of life lost (YLLs) from the number of cause-specific deaths multiplied by the standard life expectancy at the age of death. Disability-adjusted life-years (DALYs) were the sum of YLLs and YLDs. All metrics were calculated with 95% uncertainty intervals (UIs). Findings In 2023, there were 50·9 million (95% UI 46·1–56·1) road injury incident cases, 1·34 million (1·04–1·58) deaths, and 75·3 million (59·8–89·2) DALYs globally. Road injuries were the leading global cause of death among males aged 10–39 years. Between 1990 and 2023, age-standardised incidence decreased by 38·3% (95% UI 36·9–39·7) and mortality decreased by 32·3% (6·1–49·0), but progress varied widely by World Bank income group. Mortality in low-income countries (43·8 [95% UI 31·7–56·0] deaths per 100 000 population) was approximately six times higher than in high-income countries (7·5 [7·1–7·9] deaths per 100 000), despite the high-income countries showing the highest age-standardised incidence rates (858·1 [95% UI 781·9–947·1] cases per 100 000). In the past decade, many countries achieved notable reductions in road injuries, but others, including Ghana and the USA, saw increases. More severe injuries tended to occur in low-income and middle-income countries. Interpretation Although global incidence, mortality, and DALY rates from road injuries have declined, progress remains uneven, with pronounced disparities across income groups reflecting systemic inadequacies in infrastructure, vehicle standards, enforcement, and post-crash care. Strengthening emergency response, improving road design, enforcing safety measures, and adapting policies to the evolving demographics remain essential. Funding Gates Foundation.