Help Understanding

My 19 year old stepson is autistic, and I have been married to his mother for 3 years. I have learned a great deal about autism since our marriage, but I see things in his behavior and attitudes that do not seem to fit with anything I have learned about ASD. Perhaps someone can help me to understand better whether some of these things truly are related to ASD?

For example, he seems to not understand the concept of moderation at all. He may drink over a gallon of milk in one day, or drink 8 cans of Coke in one afternoon. Sometimes he may eat 8 or more eggs at a time and may add nearly a pound of cheese to his eggs, or to anything else he eats. He also refuses to eat any type of fruit or vegetable at all, and his diet consists only of meats (most of them very high-fat processed meats) and high-fat snack foods. Repeated attempts by both my wife and myself to persuade him to eat healthier and eat/drink in moderation have been consistently rejected by him.

Another thing I see is that he leads an extremely sedentary lifestyle. He refuses to work, either at a job or performing tasks at home, and from the time he wakes up until the time he goes back to bed, he sits on his computer and plays online games. He will not leave his computer except for a few minutes at a time in order to do necessary things, such as getting food, and will not stay off more than 5 minutes consecutive. He refuses to eat with us, and takes his food back to his computer to eat while playing online games. Our repeated attempts to persuade him to participate in physical activity are resisted strongly, as are our attempts to take him out of the house and go places. He is only 19 years old and already weighs over 320 pounds, so we are also very concerned about his physical healthy, especially with the dangerous mix of an extremely high-fat diet and zero exercise. Are these things related to ASD at all, or are these things merely his own peculiarities that are unrelated to the disorder? And does anyone have any suggestions about how we can persuade him to change his lifestyle, for the sake of his own health?

They can be related to autism. It seems as if he is accustomed to certain routines that he doesn't want to break from, such as how he spends his day or what activities he does. Does he presently see a therapist? If it is that serious that he won't work or do anything he is capable of doing, professional help is likely needed.

The eating I am not sure about, but the only thing I can tie that to is being obsessed with things you enjoy. Such as some people are obsessed with learning everything about a topic many other people are not interested in. I haven't heard of this with over-eating and/or drinking though. It might be something different. Maybe it is because he doesn't leave his computer except to eat, that he is very hungry or thirsty when he does and doesn't want to have to eat or drink again for awhile.

It's a routine thing, I believe. I do that actually... I'll end up with piles of empty soda cans on my desk and eat the same things over and over again. When I go inpatient and if they do blood work they generally give me a big vitamin horse pill because I'm lacking in certain things. I personally see ASD in the description. Unless he wants to change, I don't know how to convince him. I personally have an interest in green smoothies so I very well may change my diet. (That and they changed the recipe for hot pockets... )