It is essential to know that the diet of your cat is mainly dependent on age. The calorie content must be adjusted as your cat advances in age.  So yes, kittens and ageing cats have different requirements in terms of diet. When it is a kitten, it requires 30% protein in its diet. However, over time it will shift to just 26% as your cat grows. Moreover, it is best to consult with your vet as the calorie requirement changes depending on your cat’s weight and precise age.