does it make you gain weight

Rovina, having autism by itself doesn't make anyone gain weight. Obviously the same factors that apply to anyone come into play: do you take in more calories than you burn? If you don't go out a lot, if you have an unusual diet, if you don't take good care of yourself--all of these will contribute to the lielihood that you'll be overweight, but not because of autism.

Autism per se doesn't cause weight gains; however, sometimes medications that are used for symptoms that are common with people with the more severe range of Autism Spectrum may cause weight gain.  Also children and adults who experience both Autism and Down syndrome may struggle with weight issues.   Most people with high functioning Autism are active enough weight is not an issue.

 Peggy Lou Morgan