Sir weighs 51lbs. I try to feed him at least 4 cups of food a day, sometimes with half a can of wet or scraps, etc. to keep his weight up. On a good day he'll eat 5, but sometimes he just doesn't want to eat.
Recon weighs about 42lbs now. He gets no more than 3 cups a day, sometimes only two on a quiet day.
For comparison, Frag is 90lbs and doesn't get more than 2.5 cups a day.
My boys all eat Earthborn Holistics most of the time.
Bella's about 30-35 lbs and eats two cups a day of Blue Buffalo.