Objective: To determine whether there is an association between parent and sibling obesity status and obesity status in children with autism spectrum disorder (ASD).
Methods: We examined predictors of obesity in children with ASD with body mass index data for the proband, 1 sibling, and 2 parents using data from the multisite Simons Simplex Collection.
Results: In a stepwise logistic regression model, proband obesity status was associated with obesity status of the sibling (odds ratio [OR] 2.66; 95% confidence interval [CI], 1.92-3.70), mother (OR 2.10; 95% CI, 1.59-2.77), and father (OR 1.51; 95% CI, 1.15-1.98). Proband obesity was also related to somatic complaints (OR 1.60; 95% CI, 1.006-2.53), mood stabilizers (OR 1.80; 95% CI, 1.19-2.72), internalizing problems (OR 1.60; 95% CI, 1.14-2.30), age (OR 1.01; 95% CI, 1.00-1.01), and some adaptive functioning domains (OR 0.987; 95% CI, 0.977-0.997). Race, ethnicity, income, sex, and maternal education were not significant predictors.
Conclusion: Familial factors were generally the strongest predictors of obesity rather than medication use, demographics, or psychological characteristics. Results support a family-centered approach to treatment of obesity in children with ASD.