Autism and Obesity: What Are the Facts?

Autism is one of several neurological, developmental disorders. Children generally show signs of autism by the time they are three, and estimates of the prevalence of autism range from 1 in 91 children to 1 in 150. Children with autism suffer from delayed or disordered language development and have trouble communicating, forming relationships, and controlling their behavior.

Maternal obesity and Autism
Several studies have indicated that women who are obese or have maternal type 2 diabetes, gestational diabetes, or hypertension (these diseases often accompany obesity) may increase their child's risk for autism and other developmental disorders. Unfortunately, the number of women who fall into this category is significant. About 60 percent of women of childbearing age (20 to 39) are overweight, and 34 percent are considered obese.

In a meta-analysis (review of many studies) of maternal factors linked to autism, gestational diabetes is associated with twice the incidence of autism. Researchers point to an elevation of fetal glucose (sugar) levels as a consequence of maternal diabetes. They predict this increases fetal insulin secretion and leads to over-activity in a biological pathway implicated in autism.

Infants who are under- or overweight for their gestational age are also at greater risk for developmental disorders. Based on a 10-year study of six million births, babies who were large for their age were at a 21 percent increased risk of autism. Researchers believe the uterine environment is a logical culprit for the increase in risk since patterns have emerged between infant weight at gestational age and conditions such as autism.

Childhood Obesity and Autism
The National Survey of Children's Health found the prevalence of obesity in children with autism was 30.4 percent compared to 23.6 percent in children without the disorder. The link goes both ways: children with autism were 40 percent more likely to be obese. It may be that unusual dietary patterns in autistic children and decreased access to opportunities for physical activity contribute to them being overweight. Furthermore, being autistic may make it more difficult for children and their families to manage complications associated with obesity.

What to Do
Although all of the studies have limitations and it may be difficult to draw cause and effect conclusions, there is mounting evidence of an association between obesity and autism. You can tip the scales in your child's favor by entering pregnancy at a healthy weight.



MacReady, Norra. "Maternal Metabolic Conditions May Boost Child's Autism Risk." Medscape Medical News. Web. 26 May 2011.

Melville, Nancy A. "Smallest, Largest Infants Show Higher Autism Risk." Medscape Medical News. Web. 13 February 2011.

Michael Stern, Michael. "Insulin signaling and autism." Frontiers in Cellular Endocrinology  2(54) (2011). Web. 14 October 2011.

Curtin, Carol, Bandini, Linda G., Perrin, Ellen C., Tybor, David J., and Must, Aviva. "Prevalence of overweight in children and adolescents with attention deficit hyperactivity disorder and autism spectrum disorders: a chart review." BMC Pediatrics 5(48) (2005). Web. 21 December 2005.

Curtin, Carol, Anderson, Sarah E., Must, Aviva, and Bandini, Linda. "The prevalence of obesity in children with autism: a secondary data analysis using nationally representative data from the National Survey of Children's Health." BMC Pediatrics 10(11) (2010). Web. 23 February 2010.