Expect to get a lot of answers on this post. It is like arguing Ford, Chevy or Ram.

Here is some advice I picked up many years ago: Your dog should show a waistline, an indent behind the rib cage. You also do not want a flat back. You should be able to feel that backbone. Lastly, if your dog is neutered they need about 50% less food than is indicated on a required feeding label. Yes, a lot of calories go to their reproduction system. The dog may still seem hungry, but does not need it. I am sure you have witnessed many overweight, neutered/spayed retrievers in the neighborhood.

With that said, most intact GSPs are naturally lean and will burn a lot of calories,especially when working in the fall/winter. You may need more protein for your dog, in order to have her work and look to her full potential.

Plug to follow:
I feed Orijen Regional Red which is in effect 38% protein (75% meat). Link: http://www.orijen.ca/products/dog-food/dry-dog-food/regional-red/

It has given my dog all day energy in the field. In 2013, 2014, I ran her on PP sport 30/20 and in 2015 switched to Regional Red. There was not much difference in the duck blind, but quartering a field for pheasants is where I really saw it. She has much more endurance on RR and will keep a strong pace for hours. Orijen RR can be found at specialty pet food retailers. Be prepared to spend more for a higher quality food.