Increasing disparities in obesity and severe obesity prevalence among public elementary and middle school students in New York City, school years 2011-12 through 2019-20

Abstract

Recent national trends in the United States indicate a significant increase in childhood obesity, a major public health concern with documented physical and mental comorbidities and sociodemographic disparities. We aimed to estimate the prevalence of obesity and severe obesity among youth in New York City (NYC) before the COVID-19 pandemic and examine time trends overall and by key characteristics. We included all valid height and weight measurements of kindergarten through 8th grade public school students aged 5 to 15 from school years 2011-12 through 2019-20 (N = 1,370,890 unique students; 5,254,058 observations). Obesity and severe obesity were determined using age- and sex-specific body mass index percentiles based on the Centers for Disease Control and Prevention growth charts. Analyses were performed using multivariate logistic regression models with repeated cross-sectional observations weighted to represent the student population for each year and clustered by student and school. Among youth attending public elementary and middle schools in NYC, we estimate that 20.9% and 6.4% had obesity and severe obesity, respectively, in 2019-20. While consistent declines in prevalence were observed overall from 2011-12 to 2019-20 (2.8% relative decrease in obesity and 0.2% in severe obesity, p<0.001), increasing trends were observed among Black, Hispanic, and foreign-born students, suggesting widening disparities. Extending previous work reporting prevalence estimates in this population, nearly all groups experienced significant increases in obesity and severe obesity from 2016-17 to 2019-20 (relative change = 3.5% and 6.7%, respectively, overall; p<0.001). Yet, some of the largest increases in obesity were observed among those already bearing the greatest burden, such as Black and Hispanic students and youth living in poverty. These findings highlight the need for greater implementation of equity-centered obesity prevention efforts. Future research should consider the influence of the COVID-19 pandemic and changes in clinical guidance on childhood obesity and severe obesity in NYC.

Fig 1. Obesity trends over time by race/ethnicity.

Adjusted binary logit models were built, including a linear term for time (index from 0–8 or 0–3), to assess whether trends in obesity and severe obesity prevalence were significant across school years 2011–12 to 2019–20 and 2016–17 to 2019–20. Models were run for all NYC public elementary and middle school students, which were significant at p<0.001 for both time periods, and were also run separately for each race/ethnicity subgroup (p<0.05 for all subgroups from 2011–12 to 2019–20 and p<0.01 for all except Asian/Pacific Islander students from 2016–17 to 2019–20, n.s.). Models were weighted and clustered by school and student.

Fig 2. Severe obesity trends over time by race/ethnicity.

Adjusted binary logit models were built, including a linear term for time (index from 0–8 or 0–3), to assess whether trends in severe obesity prevalence were significant across school years 2011–12 to 2019–20 and 2016–17 to 2019–20. Models were run for all NYC public elementary and middle school students, which were significant at p<0.001 for both time periods, and were also run separately for each race/ethnicity subgroup (p<0.001 for all except Asian/Pacific Islander students, n.s., from 2011–12 to 2019–20 and p<0.05 for all except non-Hispanic White students from 2016–17 to 2019–20, n.s.). Models were weighted and clustered by school and student.

Fig 3. Obesity prevalence of NYC public school K-8 students by race/ethnicity and home-neighborhood poverty level, 2019–20.

Race/ethnicity by home-neighborhood poverty interaction was estimated using a logistic model of obesity in the 2019–20 school year and was significant at p<0.001. Model was weighted and clustered by school and student.