High body mass index for age among US children and adolescents, 2003-2006

Context The prevalence of overweight among US children and adolescents increased between 1980 and 2004. Objectives To estimate the prevalence of 3 measures of high body mass index ( BMI) for age ( calculated as weight in kilograms divided by height in meters squared) and to examine recent trends for US children and adolescents using national data with measured heights and weights. Design, Setting, and Participants Height and weight measurements were obtained from 8165 children and adolescents as part of the 2003- 2004 and 2005- 2006 National Health and Nutrition Examination Survey ( NHANES), nationally representative surveys of the US civilian, noninstitutionalized population. Main Outcome Measures Prevalence of BMI for age at or above the 97th percentile, at or above the 95th percentile, and at or above the 85th percentile of the 2000 sex- specific Centers for Disease Control and Prevention ( CDC) BMI- for- age growth charts among US children by age, sex, and racial/ ethnic group. Results Because no statistically significant differences in the prevalence of high BMI for age were found between estimates for 2003- 2004 and 2005- 2006, data for the 4 years were combined to provide more stable estimates for the most recent time period. Overall, in 2003- 2006, 11.3% ( 95% confidence interval [ CI], 9.7%- 12.9%) of children and adolescents aged 2 through 19 years were at or above the 97th percentile of the 2000 BMI- for- age growth charts, 16.3% ( 95% CI, 14.5%- 18.1%) were at or above the 95th percentile, and 31.9% ( 95% CI, 29.4%- 34.4%) were at or above the 85th percentile. Prevalence estimates varied by age and by racial/ ethnic group. Analyses of the trends in high BMI for age showed no statistically significant trend over the 4 time periods ( 1999- 2000, 2001- 2002, 2003- 2004, and 2005- 2006) for either boys or girls ( P values between .07 and .41). Conclusion The prevalence of high BMI for age among children and adolescents showed no significant changes between 2003- 2004 and 2005- 2006 and no significant trends between 1999 and 2006.