Beagle's & weight issues

My Beagle Charlotte has been over weight for some time now. She is 7 years old and loves to eat, eat , eat. It has affected her health and breathing and she looked like she was going to pop so I finally had her checked out really good and put her on a diet. She eats Purina Prescription Veterinary OM (overweight management diet)..and it really works. At first she stuck her nose up at it but I had to remind myself...this is for her own health. I take 2 or 3 peices of regular dog food and crush it up into a powder form and sprinkle it over her OM food and she eats it. She has lost close to 15 lbs in a month and still needs to lose probably 10 more. I can tell a difference in her energy level and everything. She is getting her girlish figure back instead of looking like a square.
I will post some better pics when I find them.