Has your cat ever gone from a happy diner to a fickle patron, refusing to eat the supper he usually gobbles right up? Or is your cat still eating, but seeming to lose weight anyway? The inner workings of a beloved feline have left many a pet parent scratching his head in worry, and according to the American Society for the Prevention of Cruelty to Animals (ASPCA), it's difficult to say what the normal weight is for cats due to the variations in breeds and individuals. There are several reasons why your cat could be losing weight, and many are easily remedied with adjustments to his diet. Read on to learn more about the most common explanations for feline weight loss.