Domestic cats are true carnivores, with teeth designed for shearing flesh and bodies superbly adapted for hunting small animals. They are thought to be descended from the African wild cat, a desert animal. Wild and domesticated cats eat most parts of their prey, usually starting with the head, but usually leave the entrails (or “guts”).
Cats have a different way of using animal protein and a higher requirement for it than dogs. In cats, protein is used as an energy source by enzymes in the liver. They can’t turn these enzymes off when a low protein diet is fed.
Cats need about 25-30% of their diet as protein, and thrive on high-fat diets (the fat content of the diet should be 25-50%). They have especially high needs for some nutrients that are supplied by animal protein. These nutrients include the protein taurine, and the vitamins niacin, Vitamin B6, and Vitamin A, and the essential fatty acid, arachidonic acid. For these reasons, commercial food that is prepared for dogs is not a balanced diet for cats.
Some cats, especially females, are very erratic feeders, but in general a cat likes to snack every few hours. Free-choice feeding is recommended (unless the cat has a weight problem), or at least three meals a day, especially during productive times (growth, reproduction, and lactation).
Any single item, e.g. canned fish, should not be more than 25% of the cat’s diet. The diet should be varied, from a young age, to prevent the cat developing a fixed food preference. Meat (muscle) on its own is not a balanced diet for a cat, being low in important nutrients (e.g. calcium).
Cats vary greatly in the amount they need to eat. Owners should aim to keep the cat at optimal weight, when the ribs can’t be seen but there is no excess fat under the skin (e.g. in the tummy area).