Obesity Fact Sheet in Korea, 2021: Trends in Obesity Prevalence and Obesity-Related Comorbidity Incidence Stratified by Age from 2009 to 2019

Background: The global public health burden of obesity has increased with socio-economic development. The Korean Society for the Study of Obesity released the 2021 Obesity Fact Sheet to address trends in obesity prevalence and comorbid conditions by different age groups. Methods: Individuals ≥20 years old who underwent a health checkup provided by the Korean National Health Insurance Service between 2009 and 2019 were included. The prevalence of obesity and abdominal obesity was standardized by age and sex based on the 2010 population and housing census. The incidence of obesity-related comorbidities was tracked from 2009 to 2019, and the incidence per 1,000 person-years was calculated using Poisson regression adjusted for age and sex. Results: Obesity and abdominal obesity prevalence has increased for the entire population over the past 11 years. Obesity prevalence has risen rapidly in individuals in their 20s and 80s compared with other age groups. Additionally, class III obesity prevalence in both men and women has significantly increased by nearly threefold. The relative risk of developing type 2 diabetes, myocardial infarction, ischemic stroke, and cancers in people with obesity or abdominal obesity is greater than in people without obesity or abdominal obesity. The relative risk was higher in young and middle-aged individuals than in the older population. Conclusion: The findings based on the 2021 Obesity Fact Sheet suggest the need to better understand obesity characteristics according to age and sex and to establish individualized treatment strategies.