Cat food must be compatible with the cat's stage of life and lifestyle to be as nutritious and beneficial as possible. Kittens, young adults, senior cats, indoor cats, outdoor cats and nursing mother cats all have slightly different nutritional needs, and different cat foods are made specifically for one or several of these groups. All nutritional cat foods share meat as a primary ingredient in addition to important added nutrients.
The primary ingredient in any cat's food should be either meat, meat by-products or seafood, according to the Cornell Feline Health Center. Preservatives, flavor enhancers and artificial colors should be kept to a minimum. Some nutrients, such as thiamine or niacin, may need to be added to the formula to counterbalance the nutrient degradation that typically occurs during the manufacturing process.
Wet and canned cat food are often the best for cats because they have a higher moisture content and are a good dietary source of water. Additionally, canned cat food tends to feature meat as the primary ingredient. Cats are obligatory carnivores, which means that they rely very highly on certain essential amino and fatty acids that are most commonly found in animal tissue. No matter what food a cat eats, a fresh supply of water must be available at all times to aid in proper digestion.