BACKGROUND: The prevalence of obesity in children with autism spectrum disorder (ASD) exceeds that of the general population, but the level of parental concern about obesity in these children is unexplored. OBJECTIVE: We estimate the prevalence of obesity in children 10-17 years in the redesigned National Survey of Children's Health (NSCH) 2016, and compare parental concern about obesity between parents of children with and without ASD. METHODS: The nationally representative NSCH 2016 oversampled parents of children with parent-report of special health care needs, including ASD. Parents opted to complete the survey via the web or surface mail. Following report of their child's height and weight, parents were asked "Are you concerned about their weight?" Response options included: "Yes, it's too high," "Yes, it's too low," or "No, I am not concerned." Obesity ( > 95th percentile BMI) was defined using the 2000 CDC growth reference. We used logistic regression to compare odds of obesity, and odds of parental concern, between children with and without ASD. RESULTS: In 24,251 children, ASD (n=699) increased obesity risk after adjusting for age, sex, and race/ethnicity (OR=1.54, 95%CI: 1.11, 2.14). ASD medication did not significantly affect obesity. ASD increased obesity concern (OR=2.17, 95%CI: 1.53, 4.81) among parents with obese children. Parents of boys with obesity and ASD had less obesity concern if he was taking medication for ASD (OR=0.258, 95%CI: 0.09, 0.78). CONCLUSION: While the prevalence of obesity is elevated in children with ASD, parental obesity concern is high, suggesting opportunities for the development of parent-focused obesity prevention and treatment interventions for this population.

BACKGROUND: We sought to assess the association between age and the prevalence of obesity among children with and without autism spectrum disorder (ASD) in the 2011-2012 National Survey of Children's Health. METHODS: Analyses were restricted to 43,777 children, ages 10-17, with valid measures of parent-reported weight, height, and ASD status. Exploratory analyses describe the impact of sex, race/ethnicity, and household income on the relationship between age and obesity in ASD. RESULTS: Although the overall prevalence of obesity among children with ASD was significantly (p < 0.001) higher than among children without ASD (23.1% vs. 14.1%, 95% confidence interval for difference 3.6 to 14.4), child age significantly (p = 0.035) modified this difference. In a multivariable logistic regression analysis, adjusted for sex, race/ethnicity, and household income, the odds of obesity among children with ASD compared with children without ASD increased monotonically from ages 10 to 17 years. This pattern arose due to a consistently high prevalence of obesity among children with ASD and a decline in prevalence with advancing age among children without ASD. These findings were replicated using a propensity score analysis. Exploratory analyses suggested that the age-related change in obesity disparity between children with and without ASD may be further modified by sex, race/ethnicity, and household income. CONCLUSIONS: The patterns of prevalence observed with increasing age among children with and without ASD were unexpected. A better understanding of the etiological and maintenance factors for obesity in youth with ASD is needed to develop interventions tailored to the specific needs of these children.