Time Trend And Demographic Disparities In Adolescents’ Obesity And Domain-specific Physical Activity From 2007 To 2020

PURPOSE: Physical activity (PA) has been associated with obesity, but few studies have examined the long-term patterns of PA and obesity prevalence among a large nationally representative sample in the United States (U.S.). This study aimed to examine the time trends and disparities of adolescents’ demographics on obesity and domain-specific PA over time. METHODS: Data came from the 2007-2020 National Health and Nutrition Examination Survey (NHANES), a series of cross-sectional cohort studies (total sample = 12,784, boys = 6479, girls = 6305, Mage = 14.20 ± 2.90). Three binary outcomes included 1) obesity (yes/no; defined as a body mass index [BMI] ≥ 95% percentile), 2) moderate-to-vigorous work activity (MVWA), and 3) MV recreational activity (MVRA). Covariates included demographics (age, gender, and race/ethnicity [White (referent), Black, Hispanic, and Other adolescents], and poverty ratio [0 (poor)-5 (wealthy)]. Logistic regressions were used to examine the changes in obesity and PA outcomes over time after adjusting for covariates. RESULTS: Adolescents in 2017-2020 were 28% more likely to be obese compared to adolescents from 2007-2008 (adjusted odds ratio [AOR] =1.28, 95% Confidence Interval [CI] =1.11-1.48, p < 0.001). Adolescents with a higher poverty ratio had 11% less likely to be obese (AOR = 0.89, 95% CI =0.86-0.92). Black, Hispanic, and other adolescents were 23% and 20% more likely to be obese and 21% less likely to be obese compared to White adolescents, respectively. No significant time trend was found for PA outcomes from 2007 to 2020. Black, Hispanic, and other adolescents were 48%,43%, and 48% less likely to engage in MVWA than White adolescents, respectively. Girls were 35% and 59% less likely to engage in MVWA and MVRA than boys, respectively. Adolescents with a higher poverty ratio had 6% and 22% more likely to engage in MVWA and MVRA. CONCLUSION: The prevalence of obesity has significantly increased from 2007 to 2020. Black and Hispanic adolescents, and adolescents living in poverty had a higher risk for obesity than their counterparts. Girls were less likely to engage in activities than boys. Future obesity interventions should be tailored to specific race/ethnic minorities and low-income families to prevent obesity and address health disparities.