Obesity Prevalence in the United States among 6 - 17-Year-Old Children and Adolescents: Measured vs. Parent-Reported Height and Weight from Two National Surveys, 2015-2018.

BACKGROUND: Previous comparison of obesity prevalence from the National Survey of Children's Health (NSCH) and the National Health and Nutrition Examination Survey (NHANES) found differences between measured and parent-reported estimates for children and adolescents. The NSCH has undergone major methodological changes prompting re-examination of the correspondence between NSCH and NHANES obesity prevalence among children/adolescents ages 6-17 years. OBJECTIVE: To compare obesity prevalence estimates among children/adolescents ages 6-17 years derived from parent-reported height/weight in NSCH (2016-2018) and measured height/weight in NHANES (2015-2018). METHODS: Obesity prevalence, height, weight, and body-mass-index for age among children/adolescents ages 6-17 years from both surveys were compared by age, sex, and race/ethnicity using absolute and relative measures of difference. RESULTS: Overall obesity prevalence was lower using parent-reported data than measured data (16.9% vs. 20.1%, p < 0.01). Estimates were similar for children ages 6-11 years (19.1% vs. 19.5%) but reported estimates were lower for adolescents ages 12-17 years (14.8% vs. 20.8%), particularly among females ages 12-13 and males ages 14-15 years. Reported prevalence was generally similar or lower across racial/ethnic groups, except among non-Hispanic Black children ages 6-9 years. Reported height, weight, and body-mass-index were typically lower than measured values. CONCLUSIONS: Parent-reported data produced similar obesity estimates for children ages 6-11 years but underestimated adolescent obesity and should be interpreted cautiously, especially for detailed subgroups.