I have always free-fed mine and none have ever had a weight problem. All are described as lean by the vet. But my Ben gained 1/2 pound in 2 weeks after being neutered. Not sure if it is a normal after surgery thing or if it is because he also had some bad teeth pulled. Maybe it is easier to eat now. Although he never acted like it was a problem before.
He has a long wy to go before it is a problem, but I may have to follow your lead and stop free-feeding. Another option would be to change to a "lite" food for weight management. Yet another would be to increase exercise, adding or lengthening a walk for instance.
Makes me feel a little guilty to limit his food as I could stand to lose some myself and I am not limiting my own food.
We don't do actual walks as he has a fenced acre to run and run he does. They all hear a sound through the privacy fence and off they go! A bird lands in the yard and off they go! The neighbor's cat sits on the fence post taunting, and ....yes, off they go!
Sometimes it is a regular comedy show, especially now with little Annie trying her best to keep up with those little 3 inch legs of hers! I love my dogs!