I've taken 12 pounds off Trouble since her amputation on Dec 12.  I believe they have instincts that tell them they need to loose the pounds.  Trouble was a chow hound!  Always wanted her food bowl filled, and would eat and/or graze at will during the day and night.  After her surgery it was critical to get the weight down, she's a bully breed that carries so much weight in the front.  I put her on a strict, measured diet with two scheduled meals each day.  She has done incredibly well, and doesn't demand food as she did before (for which I am eternally thankful).  Be persistant, you'll get that weight where you want it to be.