Figure 1.

Trends in prevalence by age group of severe obesity and obesity (which includes severe obesity) among NYC public school students aged 5 to 14 years in kindergarten through 8th grade, school years 2006–07 through 2010–11. To test for trend over school years, a multivariate model was built that included as covariates a linear term for trend, along with sex; age; race/ethnicity; school borough by district public health office (DPHO) neighborhoods (neighborhoods with low income and disproportionate rates of morbidity and mortality); free-meal status; place of birth; language spoken at home; and an interaction by age, sex, and race/ethnicity. School and student codes were used as cluster variables. All trends were significant at P <.001. Prevalence estimates of obesity (body mass index [BMI] ≥95th percentile) and severe obesity (BMI ≥120% of 95th percentile) are based on valid BMI measurements weighted by race/ethnicity, school borough by DPHO, free-meal status, grade, sex, age, and school type (elementary vs middle) to be representative of the enrollment population for each school year. Adjusted P value for trend = .04 for severe obesity among the 7 to 10 years age group.

Age Group, y	Prevalence	School Year, %					Trend for Time P value
		2006–07	2007–08	2008–09	2009–10	2010–11
Overall (ages 5–14)	Obesity	21.90	21.40	20.90	21.00	20.70	<.001
	Severe obesity	6.30	6.10	5.90	5.80	5.70	<.001
5–6	Obesity	20.20	19.40	18.80	18.40	18.20	<.001
	Severe obesity	4.30	4.20	3.90	3.90	3.70	<.001
7–10	Obesity	22.90	22.70	21.80	22.20	21.80	<.001
	Severe obesity	6.80	6.50	6.20	6.20	6.00	.04
11–14	Obesity	21.80	21.00	21.10	21.10	21.10	<.001
	Severe obesity	7.00	6.60	6.70	6.60	6.50	<.001