Continued Decline in Obesity and Severe Obesity Prevalence Among New York City Public School Youth in Grades K-8: 2011-2017.

OBJECTIVE: This study aimed to estimate population-level prevalence of obesity and severe obesity for New York City youth and examine the most recent trends over time. METHODS: All public school youth in grades kindergarten through eighth (K-8) (2011-2012 through 2016-2017) with valid weight and height measures were included (N = 1,137,782 unique students; 3,720,297 observations). Age- and sex-specific BMI percentiles for obesity and severe obesity were estimated using Centers for Disease Control and Prevention growth charts. Repeated cross-sectional analyses were conducted using logistic regression, weighting for missing or invalid responses and accounting for clustering by students and schools to examine trends over time and by sociodemographics. RESULTS: Among youth in K-8 (aged 5-15 years, 48.8% girls), the prevalence of obesity and severe obesity in 2011-2012 was 21.5% and 6.4%, respectively, compared with 20.2% and 6.0%, respectively, in 2016-2017. Since 2011-2012, decreasing trends in obesity and severe obesity (relative declines: 6.0% and 6.3%, respectively, P < 0.001) have been observed. Significant decreases were observed for all subgroups (P < 0.001), although there remained disparities in relative declines over time by race/ethnicity and poverty. CONCLUSIONS: Decreasing trends in obesity and severe obesity among all New York City K-8 public school youth are promising; however, persistent disparities highlight the need to improve intervention design and implementation strategies for groups disproportionately burdened by obesity.

The effects of changes in physical fitness on academic performance among New York City youth.

PURPOSE: To evaluate whether a change in fitness is associated with academic outcomes in New York City (NYC) middle-school students using longitudinal data and to evaluate whether this relationship is modified by student household poverty. METHODS: This was a longitudinal study of 83,111 New York City middle-school students enrolled between 2006-2007 and 2011-2012. Fitness was measured as a composite percentile based on three fitness tests and categorized based on change from the previous year. The effect of the fitness change level on academic outcomes, measured as a composite percentile based on state standardized mathematics and English Language Arts test scores, was estimated using a multilevel growth model. Models were stratified by sex, and additional models were tested stratified by student household poverty. RESULTS: For both girls and boys, a substantial increase in fitness from the previous year resulted in a greater improvement in academic ranking than was seen in the reference group (girls: .36 greater percentile point improvement, 95% confidence interval: .09-.63; boys: .38 greater percentile point improvement, 95% confidence interval: .09-.66). A substantial decrease in fitness was associated with a decrease in academics in both boys and girls. Effects of fitness on academics were stronger in high-poverty boys and girls than in low-poverty boys and girls. CONCLUSIONS: Academic rankings improved for boys and girls who increased their fitness level by >20 percentile points compared to other students. Opportunities for increased physical fitness may be important to support academic performance.