I can't say for everyone but my 7 yr old barely weighs 40 lbs. She has CP. She doesnt have a very good appetite somedays its a real challenge to get her to eat. Shes always been small. A few other mothers that I have talked to say the same thing. But if your the weight makes you uncomfortable on your nest visit to the Dr. make sure to address it with them so they can give their expert opinion, and may help to settle your questions or fears. Hope That Helps.