Veterinarians do recommend home-cooked diets for some specific purposes. For example, home cooked diets are used to treat food allergies but food allergies are rare. If you are concerned about a food allergy then first consult a veterinarian, use a defined recipe prepared by a specialist and have your veterinarian check your cat at least every two months while it is on the diet. Unfortunately, even if cats are fed a balanced home-cooked diet, they will usually select between various ingredients so the diet consumed is unbalanced. Nutritional problems usually occur in my veterinary practice as a result of feeding human foods and supplements and do not occur from feeding cat food.
Many people like to give human food as treats to their pet.
Try to keep these to a minimum. Uncooked human food represents a major risk for infection to cats and their owners. No additives are necessary and can be dangerous. For example, extra meat can cause bone wasting and fractures, excess calcium can damage the kidneys, too much liver can cause boney outgrowths, excess vitamins can cause vomiting. Some have suggested adding carnatine, vitamin E and other nutrients, however, most cat foods contain these nutrients and it is still unclear if increased amounts provide any therapeutic benefit or what dose is necessary.