Obesity Among Children and Adolescents in NHANES August 2021-August 2023: An Examination of Race/Hispanic Origin Subgroup Estimates.

Background: The National Health and Nutrition Examination Survey provides nationally representative data on child obesity using measured height and weight. Due to COVID-19, the NHANES August 2021-August 2023 cycle had design changes and smaller sample sizes for certain race/Hispanic origin groups. The objective is to explore sex and race/Hispanic origin-specific childhood obesity trends.

Methods: Trends from 1999 or 2007 to August 2023 were evaluated in regression models. Obesity was defined as BMI-for-age ≥ 95th percentile.

Results: Analyses included 28 666 youth 2-19 years. From 2007 to August 2023, obesity prevalence increased among Hispanic girls (p = 0.03) but not Hispanic boys (p = 0.06). From 1999 to August 2023, obesity increased among non-Hispanic White (White) boys (p = 0.02) and non-Hispanic Black (Black) girls (p = 0.04), but not White girls (p = 0.10). Among Black boys only, a quadratic trend (p = 0.03) was found, driven by an obesity increase between 2017-2018 and August 2021-August 2023, from 19.4% to 38.1% (p < 0.01).

Conclusions: Obesity increased among Hispanic girls, White boys, and Black girls. The prevalence increased in Black boys too, but the magnitude of increase from 2017 to August 2023 appears implausible. Small August 2021-August 2023 sample sizes for Black youth could have exacerbated unmeasured sampling variation. Continued surveillance will provide context for interpreting estimates.