Big baby.

Anyone else ever have a nine month old that wears eighteen month size clothing? My son eats and eats and eats and the doctor wanted him on a diet but taking food away from my child would make him extremely mad, and I feel if he is eating I should just let him. He was a preemie when he was born and was very sick and went from hardly eating to eating all day long and being ahead of children that are at a year old when he is only nine months 🙁 should I get a new doctor?