Go with the recommended dosages on the bag. If the pup still seems hungry then I would give it a little more....as long as it doesn't start to look fat.

My younger GSP (4 yrs old now) would eat and eat and eat when he was younger (and still does) and he was always very skinny looking. Right now, I feed him two coffee cans of dry dog food and a can of "soft" dog food. Sometimes he even eats more! And he isn't even close to being fat......he's just a monster! I run my dogs everyday for a few minutes though, so he is constantly active and burning off any excess fat that he might accumulate. Hope this helps!