That is what I feed my guys also! Hmmm... I am also playing with the amounts. My male get a cup twice a day, female gets 3/4 cup twice a day. They seem to get a wicked energy "boost" right after they eat, so I have been wondering if it is too high calorie. The grain-free foods seems to be higher calorie, and of course high protein, so I also wonder if that is where I am having trouble (maybe same for you????)....
My two are 1 year 3 months now, and I am still figuring out the food thing. I am debating whether to just go back to Wellness "reduced weight"... they did well on it, and it was lower cal and lower protein but it isn't a "grain-free 6-star" food and I felt I should change. I would still like to them each drop a pound a or two, but it just doesn't seem to happen. I am giving NVI LID another month, will let you know how it goes..... (that food here in Canada is very expensive, and special order only. Stores don't even stock it!).