When to Switch
When your cat is about 12 months of age, it's time to change her diet to a premium maintenance formula. When you transition your cat to an adult diet, it's important to monitor her weight and body condition and adjust portions if necessary.
Because cats generally eat only what they need, free-choice feeding is adequate for most cats. (Free-choice makes food available to your cat around the clock and lets her eat when and how much she needs.) Indoor cats that don't get much exercise, however, may overeat if fed free-choice. For them, portion-controlled feeding twice a day is a better routine.
To determine how much food to give your cat, check the recommendations of the pet food manufacturer on the label. Use the guidelines and weigh your cat on a weekly basis. If your cat is gaining or losing weight and shouldn't be, slightly adjust her daily intake and weigh her again the following week.