Puppies need more food than adults. On a grain free diet, fromm, tast of wild etc, dog eat less as its more nutritional. I have all mine on a diet now as they were gaining too much wt over the winter on their normal 3/4 cup at night, at 1/2 I am seeing a wt loss in my biggest boy. My old boy is losing too much weight, so I had to adjust him back up. Mixing vegetables in is a great way to get them to loose wt if they will eat it, mine pick out the kibble arount the veggie and opt to go hungry vs eating those nasty green things.
If you feel cush vs ribs when you grip thier sides, the dog is too fat. You should feel sleek muscle and ribs down thier sides. Mine are only too thin when their hips show.