Obesity is a significant modifiable risk factor for dementia. This study aims to quantify the global impact of obesity on dementia burden and examine how national strategies for managing overweight/obesity and dietary factors influence dementia prevalence and mortality, with a focus on sex-specific differences. We used data from the Global Burden of Disease (GBD) and World Health Organization (WHO) to evaluate the association between obesity age-standardized prevalence rate (ASPR) and dementia age-standardized mortality rate (ASMR) and ASPR across 161 countries. A two-step multivariate analysis adjusted for socioeconomic and lifestyle factors was performed. Temporal trends in dementia were analyzed based on the presence of national obesity management strategies and varying dietary scores. A 1% increase in national obesity prevalence was associated with a 0.36% increase in dementia mortality (OR: 1.0036; 95% CI: 1.0028–1.0045) in males and 0.12% in females (OR: 1.0012; 95% CI: 1.0007–1.0018). A 1% increase in national obesity ASPR was associated with an increase in ASPR of dementia by 0.26% for males (OR: 1.0026, 95% CI: 1.0024–1.0028) and 0.05% for females (OR: 1.0005, 95% CI: 1.0004–1.0006). Males exhibited a higher susceptibility to obesity-related dementia. Countries with national obesity management strategies showed a significantly greater reduction in dementia mortality, particularly among females (P = 0.025). Higher dietary scores were associated with a more significant decrease in dementia prevalence across both sexes. Rising obesity prevalence is linked to increased dementia burden globally, with males being more vulnerable to this relationship. National management of overweight/obesity and healthier dietary habits may help mitigate the dementia burden, emphasizing the need for integrated public health interventions.

肥胖是痴呆的一个重要可改变的危险因素。本研究旨在量化肥胖对痴呆负担的全球影响，并检查管理超重/肥胖和饮食因素的国家战略如何影响痴呆患病率和死亡率，重点是性别特异性差异。我们使用来自全球疾病负担 （GBD） 和世界卫生组织 （WHO） 的数据来评估 161 个国家的肥胖年龄标准化患病率 （ASPR） 与痴呆年龄标准化死亡率 （ASMR） 和 ASPR 之间的关联。进行了针对社会经济和生活方式因素进行调整的两步多变量分析。根据国家肥胖管理策略的存在和不同的饮食评分分析了痴呆的时间趋势。全国肥胖患病率增加 1% 与男性痴呆死亡率增加 0.36% （OR： 1.0036;95% CI： 1.0028–1.0045） 和女性 0.12% 相关 （OR： 1.0012;95% CI： 1.0007–1.0018）。全国肥胖 ASPR 增加 1% 与男性痴呆 ASPR 增加 0.26% 相关 （OR： 1.0026， 95% CI： 1.0024–1.0028） 和女性 0.05% （OR： 1.0005， 95% CI： 1.0004–1.0006）。男性对肥胖相关痴呆表现出更高的易感性。制定国家肥胖管理战略的国家显示痴呆死亡率的降低幅度显著更大，尤其是在女性中（P = 0.025）。较高的饮食评分与两性痴呆患病率的更显着降低相关。肥胖患病率的上升与全球痴呆症负担的增加有关，男性更容易受到这种关系的影响。 国家对超重/肥胖和更健康的饮食习惯的管理可能有助于减轻痴呆症负担，强调需要综合公共卫生干预。