This whole "carbs & children" thing is a touchy subject and I have nothing but admiration for parents dealing with it. I've known parents who will hunt their children down like escaped convicts over a Tootsie Roll, yet let them eat all the fries they want, not realizing it is just as bad for them.
As always, real food trumps fake food. The sooner children realize that, the better they are able to make good choices.