Cats are obligate carnivores, with nutritional needs unlike ours — or even a dog's. They have little use for carbohydrate and rely on protein for most of what keeps their bodies running. And of all the nutrients advertised on pet-food labels, taurine — an essential amino acid cats can't make enough of on their own — is the one most tied to their well-being. Enter the numbers from the Guaranteed Analysis box on any label and see how the food really stacks up.
Type the percentages from the “Guaranteed Analysis” panel. The four are required; add taurine too if the label lists it.