Okay, I may be being a bit paranoid here, but bear with me.
We adopted Diesel just shy of a month ago. He was very malnourished and underweight. He was weighed approx. a week after we adopted him, and weighed 55 lbs. It's hard to judge, but ideally we think he should be around 80lbs... maybe more.
We have been feeding him a fair amount of food. He is eating about 1 lb. of raw in the A.M. and 3 cups of kibble in the P.M. (Kirkland Lamb & Rice).
He seems to be gaining weight very slowly. We weighed him today and he has only gained 5 lbs in the last month. He does look a bit better, but his ribs and hip bones still jut out.
I have never had a dog that needed to gain a fair bit of weight, is 5 lbs in a month normal? He has been to the vet and has a clean bill of health. Should I maybe switch to a puppy kibble? He is fairly young - we estimate around 9-10 months.
He is fairly active. We usually do about an hour of exercise at the dog park a day plus him and Brynn play together alot.

Perhaps I should increase his amount of food? But already he is eating so much, and sometimes needs a fair amount of coaxing to finish his meals.
Ideas?