Anorexia nervosa (AN) is an eating disorder that is significantly associated with severely impaired physiological functions, multiple organ failure, and suicidal ideation. This study aims to estimate the global, regional, and national secular trends of AN burden based on Global Burden of Diseases (GBD) 2019 data. The pertinent data for AN were collected from the GBD Study 2019. The long-term trends of the burden of AN were analyzed in different Social Demographic Index (SDI) regions by Joinpoint regression, Age-Period-Cohort analysis, and the Estimated Annual Percentage Changes. This study found that the global burden of AN gradually increased over the past 30 years, with the highest burden remaining in high-income countries, but the biggest increasing trend was observed in Asian region. AN was more common in adolescents and young women, but it was growing rapidly in adolescents and young men. Disability-adjusted life years (DALYs) caused by AN was the highest in the age group of 15-24 years among all SDI levels. The risk of AN rapidly increased since the beginning of the twenty-first century apart from high SDI regions, and it was higher in later-born cohorts than the earlier ones in various SDI areas. Future studies could verify our findings by using individual-level data. Our findings could help policy makers around the world understand the burden of AN in their countries and develop appropriate health policies for prevention and early intervention for high-risk populations.