How do I get my six year old to gain weight? He is on ADHD meds and taking him off of them is not an option. He weighs about 45lbs not sure how tall he is. When he takes off his shirt i feel so bad because i can count his ribs & vertabrae. I feed him constantly. I dont buy junkfood. His dr said to up his calorie intake and give him pediasure or something like it well he wont drink the stuff and i dont blame him its nasty. Any suggestions that don't involve his meds?