By Dr Ananya Mandal, MD
There is a great interest in the link between obesity and autism among children. This is mainly because of the huge rise in the number of obese children over the last two decades especially in the Western World.
At present, the prevalence of obesity among children and adolescents between ages 2 and 19 years in the United States is 16.3% and the prevalence of those that are overweight is 31.9%.
Childhood obesity further raises the risk of several disorders like diabetes, heart disease, sleep apnoea, menstrual irregularities, orthopaedic problems etc.
What is autism?
Autism is a developmental disorder. The onset is usually in childhood at the age of 3 years. Autism spectrum disorders (ASDs) describe a wide range of conditions that include Asperger syndrome, childhood disintegrative disorder, PDD-Not Otherwise Specified, Rett syndrome etc.
The prevalence of ASDs is currently estimated to be anywhere between 1 in 91 to 150 individuals.
Autism is typically characterized by delayed and disordered language development, delayed and difficulties with social skills, communications, presence of stereotypic behaviors, a tendency towards behavioral rigidity and sensory and behavioral problems.
Aim of studying obesity and autism
The aim of studying the association between childhood obesity and developmental disorders like autism is to assess the underlying connection and pathophysiology and if positive devise ways to prevent both conditions.
Research into obesity and autism
Curtin and colleagues published their findings in 2010 dealing with the association between these two conditions. (1) They looked at 85,272 children between ages 3 and 17 and assessed if they were diagnosed with autism and classified them as obese according to CDC guidelines for body mass index (BMI) for age and sex.
Their results showed that the prevalence of obesity in children with autism was 30.4% compared to 23.6% of children without autism. The authors concluded that children with autism have a high prevalence and risk of obesity and research needs to focus on the propensity of autistic children developing obesity.
Autism and eating habits
Children with autism may have unusual eating habits, most frequently described as overly selective or picky eating. There have been studies that show that autistic children prefer energy dense foods including high fat foods. It is possible that these eating patterns may contribute to the development of obesity in this population of children.
Autism and obesity in pregnancy
Further there have been studies that show that autism is more likely to occur in children whose mothers were obese while pregnant. One such study involved about 1,000 California children, ages 2 to 5. They found that obese mothers face the risk of autism as well as other developmental delays in their babies.
In addition pregnant mothers with diabetes have nearly 2 1/3 times the chance of having a child with developmental delays compared with healthy mothers.
Thus when a normal mother has a 1 in 88 chance of having a child with autism, an obese mother has a 1 in 53 chance of having a child with autism. (4)
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)
Last Updated: Apr 8, 2013