either ways, both cause weight loss
both cause weight loss. However, the medical evidence goes more in favor of Adderall here. That means several studies have shown that Adderall causes more weight loss. In a clinical study of 255 adult patients taking it, 10% reported to have weight loss during the course of treatment.
There are no such clinical studies on Ritalin. However, Ritalin also causes weight loss.
Since you are 22 yrs old now, there is little disturbance of either drugs on your growth and metabolism
. Your treating doctor can choose the drug for you.
If I were your treating doctor, and you do not wish to lose weight, I would try Ritalin instead of Adderall in you.
Hope this clarifies.