That sounds... Really weird.
Are you sure those statistics aren’t artificially twisted by those nonvocal super autists you hear about every now and then, escaping their pen?
And then get hit and killed by a truck or something, because they like machinery but are totally unable to function by themselves and have never left their house alone?
Speaking of autists in general, most of the ones I’ve seen live a pretty unhealthy lifestyle: Eating the same foods religiously, often fast food, and getting little in terms of exercise and socialization.