Instructions
Make an appointment with your veterinarian to have a thorough physical examination performed on your cat. Blood and urine tests may reveal physical and metabolic disorders, such as a thyroid imbalance, which can cause your cat to gain weight. If the tests find any health irregularities, ask your veterinarian for advice before providing a new diet for your cat.
Choose a cat food that is high in fat and protein to accommodate your cat's physiology, which is designed to thrive on a carnivorous diet. The guaranteed analysis label on the cat food should designate a protein content over 30 percent and fat content over 18 percent of the dry matter. Find the dry matter percentage by dividing the percentage of fat or protein by the percentage of the food that is not moisture. For example, a cat food whose guaranteed analysis label indicates 50 percent moisture and 15 percent protein contains 30 percent protein on a dry matter basis.
Calculate the correct daily portion size for your cat according to the following formula: daily portion in ounces = (R * W) / (16 * D). R indicates the daily calorie requirement per pound of body weight. According to Max's House Animal Rescue, Inc., an active cat requires 20 to 30 calories per day per pound of healthy body weight, while an inactive cat requires 18. W indicates your cat's healthy body weight in pounds. D indicates the calorie density of the cat food, marked on the cat food packaging in units of Kcal/lb, or calories contained in each pound of food.
Transition to the new type of food gradually. Provide one to two feedings a day, with a total weight equal to the daily portion size you calculated. Add slowly increasing proportions of the new food in with the old food over a period of three to four weeks.
How to Feed a Cat Who Overeats
According to T.J. Dunn, DVM, one of the likely leading causes of feline obesity is "free choice" feeding. In free choice feeding, the cat owner leaves food out for the cat at all times and allows the cat to eat at will. This reverses the diet and exercise patterns that cats experience in the wild, where they must exert themselves by hunting prey before eating. To combat weight gain, transition your cat to periodic small portions of nutrient-rich food.