A study from Tufts University School of Medicine found that at age 10, obesity rates among children on the autism spectrum are not that much higher than children outside the spectrum, but rates diverge sharply as children get older.
Children and adolescents on the autism spectrum may be more likely than their peers to be obese—and to stay that way, according to a new study from Tufts University School of Medicine.
The findings, which appeared online Tuesday ahead of publication in Childhood Obesity, used data from the National Survey of Children’s Health from 2011-2012 and covered children ages 10 to 17.
The data set included height, weight, gender, and autism spectrum status for 43,777 children. Obesity rates remained steady among children on the autism spectrum but declined among children who did not have autism spectrum disorders.
Researchers noted that they found a gap between children with and without autism, but it wasn’t quite they anticipated. “What we found was that the disparity did increase with age over adolescence, but the underlying patterns were not as expected,” said lead author Aviva Must, PhD, who is chair of public health and community medicine at Tufts.
“The prevalence of obesity in the (autism spectrum) group was high and remained so, while the prevalence in children without (autism) declined over adolescence," Must said.
Overall, obesity prevalence among children on the autism spectrum was 23.1%, compared with a 14.1% rate among children outside the spectrum. Prevalence remained consistent among children on the autism spectrum between ages 10, when the obesity rate was 20%, and age 17, when it was 22.1%. Among children outside the spectrum, the obesity fell by half, from 19.1%, which is nearly the same as those on the autism spectrum, to only 8.3%.
The researchers examined obesity trends by gender and race. Obesity prevalence for those with autism increased in boys but decreased in girls during the adolescence, and increased among white teens with autism while falling among white teens outside the spectrum. The findings could suggest long-term health effects, according to the researchers.
“Factors to consider with obesity in children with (autism spectrum disorder) are sensory sensitivity, the need for routine or sameness, behavioral rigidity, use of food as a reward, mealtime stress, and parental stress; any or all of these could contribute to obesity,” said co-author Linda Bandini, PhD, an associate professor at the University of Massachusetts Medical School Shriver Center.
Bandini noted that many teens get their exercise through high school sports, but children on the autism spectrum may be less likely to participate in these activities. And often, parents with children on the autism spectrum report using television as a reward, even though it is a sedentary activity. Medication, which is commonly used among children with developmental disabilities, can play a role in weight gain, but data were insufficient to gauge how much its use contributed to the results.
Must A, Eliasziw M, Phillips SM, et al. The effect of age on the prevalence of obesity among US youth with autism spectrum disorder. Childhood Obes. 2016; doi:10.1089/chi.2016.0079