As an adult who went 28 years before getting ADHD medication, I rather liked the whole "no appetite" thing :)
I think it's important for ADHD kids to learn to deal with their differences (note: imho ADHD is not a disorder, or a problem, or a deficiency, we're just a particular set of personality traits that do not do well in modern social norms that require most people to sit still and perform repetitive tasks all day every day) without medication. After I was diagnosed at 28, friends who have ADHD kids started asking me about medication and such. I strongly suggested they avoid it as long as they can; I think it's important for the kids to be able to recognize the differences in their own behavior when using medication, and to learn to cope with their tendencies without it first.
I took Concerta for four months, then stopped. I learned how much of a difference it made in me, and learned to recognize in the morning when I was going to have a particularly ADHD day. When I start the day like that, I pick up a coffee on the way to work. That's all the stimulant I need.