Expert: Dr. Sharon A. Mitchell - 6/17/2010

Question
I have a 16 year old son called Harry. He has Asperger's syndrome, is doing well in school, has good social skills, is good at cooking. It's his special interest that's concerning us though - eating.

He will overeat simply for the sake of it, and at one time we had a phone call from his college saying he'd eaten all 48 packets of crisps on a trip that were meant for the students.

I asked him why he overeats, and he says it's simply because he enjoys food. He once drank 8 bottles of Diet Coke in one day and complained he still was hungry!

If he gets money, he spends it on food. He also has a part-time job in a convenience store but spends his money as quickly as he earns it - again, on food and drink.

We're worried he will become overweight.


At least we know why he eats so much, we've tried everything - locking cabinets, making him ask us for food, but he's still eating and eating.


How should me and my husband cope with this situation, and is this an odd special interest amongst AS children?

Answer
While it's definitely not odd for a person with an autism spectrum disorder to have a special interest, it is not common for the interest to be in eating food to this degree. Is this a new development?

I understand your concern about possible excess weight gain. You must also be concerned about the quality of his diet. If he drinks that much pop or eats that many snacks he will not have room for nutritious food.

As you know, autism (and Asperger's) are neurobiological disorders. Sensory differences are common - the individual has trouble processing sensory input in a typical way. Some people with autism have a high registration threshold, meaning it takes a lot of stimulation for the sensation to register on them. Do you think that this might be what is happening with your son - it takes a lot for him to register the sensation of fullness?

Research shows that there are some neurological differences in the brains of people with autism spectrum disorders (ASD). Among some of these may be differences in the hypothalamus that could be affecting your son. Here is a link that will take you to an article on overeating and autism: http://www.autism.org.uk/en-GB/Living-with-autism/Understanding-behaviour/Dietar...

This next article lists some behavior strategies you might consider. http://www.autism-india.org/apr98.html

Your son sounds like an intelligent young man. What does he say about this? Does he understand your concerns? Does he understand that his current eating patterns are not normal or healthy? Is he a rational type of person who will respond to logic? Is he a rule-follower who would comply with the rule of eating only within specified time frames and only imbibe specific quantities? If you can engage him in setting these rules you may be able to get him to agree to a contract to abide by these rules.

Mood disorders are not uncommon in young adults with ASD. These can included some degree of depression. In teens depression does not always look like the sadness we think of in adults. Instead it may come out in anger, aggression and/or obsessive-compulsive tendencies. If your son is struggling with compulsions, this could be a factor in his over eating. Although none of us want to see our children take medications, there are times when the correct meds can have a significant positive impact on behaviors, such as compulsions.

I would suggest that you should involve your physician in this. There are other disorders that cause over eating, such as Prader Willi Syndrome (http://www.pwsausa.org/syndrome/index.htm). A doctor can rule out a genetic abnormality such as that which causes Prader Willi or other physical reasons that could account for his over eating. Since your son is 16, now is the time to work intensively with him on this before he goes off to college on his own.

Best wishes,

Sharon A. Mitchell, B.A., B.Ed., M.A., PhD candidate