Objectives: To analyze cross-sectional data on BMI, energy/activity level, and food intake for children with ASD, and their unaffected siblings, ages 3 to 17.
Methods: Parents provided data on height, weight, and related factors for 1,435 children with an ASD (85% male) and 1,011 of their unaffected siblings (47% male) using a web-based interface. Approximately half the measurements were obtained at a health provider’s office. Key variables were compared by ASD status, age group, and gender. A five point Likert scale was used to measure energy/activity level and food intake.
Results: Affected children ages 6-11 and 12-17, both girls and boys, had a significantly higher BMI compared with unaffected siblings (p<0.05). However, this was not the case for those ages 3-5. As expected, more girls and boys who were overweight had medical problems or were taking medications that are known to affect weight and/or height (p<0.05). Younger children with ASD had higher levels of hyperactivity, as compared to teenage children with ASD, who had low levels of energy/activity (p<0.001). Similarly, younger children with ASD were reported to eat a less-than-normal amount of food, while their teenage counterparts were reported to eat a more-than-normal amount of food (p<0.01). In contrast, a stable, more normal energy/activity level and amount of food consumed were reported for unaffected siblings.
Conclusions: There is a need to further explore the causes of elevated BMI in autism spectrum disorders, as well as to address the health risk this may pose.