Obesity is the No. 1 nutritional disease seen in cats. In fact, more than 35 percent of the cat population is considered overweight. You mentioned that your cat weighs 15 pounds, but it is important to know how much overweight this is. For certain types of cats, 15 pounds may not be far off the normal weight, so always check with your veterinarian to determine what the cat's ideal weight should be.
There are a couple of conditions that may be complicating your feline's ferocious appetite, including diabetes mellitus and thyroid disorders -- both of which may be detected from a blood test performed by your veterinarian. Be sure to have these tests done before you put your cat on a weight-loss campaign. If all is clear, then you must begin to cut back on Annie's calories and increase her exercise. Remember, for best results, losing weight must be a two-pronged approach.
Feed a diet specially formulated for losing weight. Dry, canned or a combination of the two can successfully be used to help your cat lose weight. Just remember you'll need to monitor how much your cat eats, so try to feed your cats separately if you have more than one feline.
Also, keep your cat occupied with lots of exercise and new play toys. Remember to hold weigh-ins weekly, either at home or at your veterinarian's office, so you can monitor the weight loss closely and see the results.