Hi,
My 8 yr old son also takes Adderall XR, but only 15 mg. (for the past 2 yrs.) He was really skinny for a while back in first grade but my husband is tall & thin so we figured that was OK. My dr. said to give our son a milkshake at bedtime every night, and I can add protein if he seems to need it. As he has grown it affects him less than it did at first; he never has trouble sleeping and he has a good appetite at breakfast. I try to get healthy cereals like Total, granola, or multigrain Cheerios. And we use the gummy bear vitamins. I don't know if they help very much but I feel better with him taking them. Finally we use fish oil, which helps with stress, which every family with ADD has lots of.
You are right that sleep and food are essential for a healthy child. If my son were having as much difficulty as you describe, I'd reconsider the dosage or maybe try something else. A friend of ours swears by Metadate. Her son had a great appetite last year (he was in my 2nd grade class) and our principal told me about a jr. high girl with ADD who could tolerate no meds except Metadate. But every child is different. For example, Dr. Amen says there are 6 or 7 different kinds of ADD and they require very different treatments. Good luck and don't give up....mehc
My son is on adderall as well, and he had the same problem not wanting to eat. I usually wait until bed time to give dinner because the medicine is mostly out of the system by then. I also give him breakfast before he takes the pill in the morning. As for lunch he usually skips it. The doctor said this ok. You should try to give him vitamins chewable if he'll take them or there are kinds you can mix in juice. These meds have a tendancy to deplete vitamins in thre body. I was never told this by the doc, the pharmacist told me.