showboydickie choc labs are generally of a chunkier build. Not to say they can't be lean.
Have a chat with your local vet if it helps. Ours gave us some useful advice about the first 12 months with our lab and to keep an eye on quantities versus the dogs change in build (was told when rubbing there sides you should always be able to gently feel their ribs).
So don't just go by what the packets of food say as they will let you gladly over feed as it will only line the companies pockets!