You are exactly right. In fact, congrats for realizing and getting off the stim meds. A lot of people wind up getting addicted who do what you did if they don't have ADHD.
I was overweight and took Adderrall to give me the energy to run and lose a LOT of weight. It was great fitting into those size 4 jeans but my face looked terrible. I looked old and gaunt. I had circulation issues because Adderrall is a vaso constrictor. Also my heart would beat very fast. I had no appetite, was cranky a lot, and was malnurished from lack of healthy food. It affected my brain, because I was depressed if not on it.
I ignored all of that because staying slim was more important to me. When I finally went of, gained the weight back, I was happier, but back to square 1. Its the law of physics, everything has an equal and opposite reaction, what goes up must come down. Unless you have ADHD, dont take it for the weight loss alone, and even if you take advantage of that perk, be careful you still eat and take care of yourself.
While you can do it for staying slim, etc. It is very helpful for ADHD symptoms. See this link - http://www.theatlantic.com/health/archive/2014/09/exercise-seems-to-be-beneficial-to-children/380844/#comments