As noted above, cats in the wild wouldn’t take in carbohydrates in the form of starches and sugars. They would instead derive most of their energy from fat, which they have a great need for. In fact, adult cats require a diet that is about 10 percent fat to stay healthy, and kittens require even more.
So many adults now are obsessing over eliminating fat from their diet that they foolishly try to impose their own diet regimens on their pets, and this is not a good thing. Too little fat can lead to weight loss, susceptibility to infection, slow healing of wounds and other problems. Another point to remember: cats can only metabolize animal fat; they cannot metabolize the fat in vegetable oils.