My 3 year old only weighs 100?

I think my doctor is a quack, or Canadian. I took my son to the doctor for his 3 yr check up. He weighed 100lbs, poor guy he is so short for his age. The doctor said it was very important he lost weight, she just didn't understand my argument of trying to make him taller. All she talked about was making his meals colorful. Colour, colour, colour!!! So For about a week he has been on a stricked diet of red lolipops, green jolly ranchers, lemon heads, pink peeps.. they were so cute. He has already put on 10 more pounds, I am starting to think this doctor did not know what she was talking about wouldn't you agree?