I don't know if it is the line or the food, but I haven't really had too much of an issue with "fat" puppies. However, I've seen many that I would consider fat. And, I've also noticed often you have splayed feet and down on the pasterns.
They will reach whatever weight and size they are meant to be as they grow and mature, and making a puppy overweight is not going to change that. It will only change other conditions, such as the bad feet, even hips, and perhaps toplines, IMO
