Updated Waist Circumference Percentiles and Central Obesity Prevalence Among U.S. Children and Adolescents, NHANES 2011-2023.

BACKGROUND: Pediatric obesity affects 20% of children and adolescents globally. Waist circumference (WC) identifies central adiposity and cardiometabolic risk, yet pediatric WC percentiles are outdated. This study provides updated age- and sex-specific WC percentiles reflecting current trends to improve clinical risk assessment. METHODS: We conducted a cross-sectional analysis of National Health and Nutrition Examination Survey (NHANES) 2011-2023 data among U.S. youth aged 2-18 years. Central obesity was defined using International Diabetes Federation criteria. WC percentiles (10th, 25th, 50th, 75th, 90th) were estimated by single-year age and sex, with race and ethnicity comparisons. Quantile regression assessed distributional differences versus NHANES 1999-2008 and examined demographic differences in WC using survey logistic regression. RESULTS: Among 14,763 children and adolescents aged 2-to-18 years, the overall prevalence of central obesity was 14.08%. Mean WC was 52.05 cm (95% confidence interval [CI]: 51.80-52.30) for ages 2-5, 62.04 cm (95% CI: 61.57-62.52) for ages 6-9 years, 76.93 cm (95% CI: 76.31-77.55) for ages 10-15 years, and 84.75 cm (95% CI: 83.87-85.63) for ages 16-18 years. Hispanic youth had higher odds of exceeding WC percentiles compared with non-Hispanic White (NHW) peers (males: odds ratios [ORs] = 1.37-1.89 across 50th-90th percentiles; females: ORs = 1.26-1.35 across 25th-90th percentiles, all P < 0.05). Non-Hispanic Black (NHB) males had lower odds (ORs = 0.41-0.82 across 10th-75th percentiles), while females had higher odds only at upper percentiles (75th: OR = 1.26; 90th: OR = 1.52, all P < 0.05). Non-Hispanic Asian youth had significantly lower odds across all thresholds. Among Hispanic, NHW, and NHB youth, WC percentiles were higher in 2011-2023 than in 1999-2008, with the greatest increases at the upper percentiles. CONCLUSIONS: WC percentiles among U.S. youth have increased over time. Updated age- and sex-specific reference values may improve early risk identification and pediatric obesity screening.