Prevalence and Sociodemographic Correlates of Obesity Among US Youth Aged 2-19 Years: An Analysis Using Pooled 2011-2018 National Health and Nutrition Examination Survey (NHANES) Data

Background: The burden of pediatric obesity in the United States continues to pose substantial health and economic challenges, with persistent and evolving disparities across demographic and socioeconomic groups. Identifying groups at highest risk is essential for guiding targeted interventions. Objective: The aim of this study was to determine the nationally weighted prevalence of obesity and identify independent demographic and socioeconomic correlates among US youth aged 2-19 years using the pooled 2011-2018 National Health and Nutrition Examination Survey (NHANES) data. Methods: A nationally representative, survey-weighted cross-sectional analysis was conducted using pooled NHANES cycles from 2011 to 2018. The study population included children and adolescents aged 2-19 years with complete anthropometric and demographic data. Obesity was defined as body mass index (BMI) at or above the age- and sex-specific 95th percentile according to the Centers for Disease Control and Prevention (CDC) growth charts. Demographic and socioeconomic associations were analyzed by survey-weighted descriptive analyses and multivariable logistic regression models with the complex sampling design considered. Results: Obesity prevalence varied significantly by age group, household income-to-poverty ratio, and race and ethnicity. Higher odds of obesity were observed among adolescents aged 12-19 years compared with children aged 2-5 years. Youth from low-income households (income-to-poverty ratio <1.3) had significantly higher odds of obesity compared with those from high-income households (OR = 1.85; 95% CI: 1.50-2.30; p < 0.001). Significant disparities were also observed across racial and ethnic groups, with Mexican American youth demonstrating the highest prevalence. Sex was not independently associated with obesity after adjustment. Conclusion: This study demonstrates persistent demographic and socioeconomic differences in pediatric obesity in the United States. The findings support targeted prevention efforts and highlight the need for longitudinal research to better understand pathways linking social conditions and obesity risk.