I also feed Barking Heads and Darwin is skinny - only 10Kg, but I know his current weight is right for him. He's 3 and 1/2yrs and over the winter he put on a little extra weight, which he lost over the spring. Barking Head feeding guidelines are very vague. Between 100 - 200gm for a 10Kg dog. So I feed approx 160gm a day split between 2 meals, Gravy Bone at 6am and a carrot at lunch.