Some chemical additives to watch out for in cat food include BHT, BHA, and Ethoxyquin, which are very efficient chemical antioxidants but are suspected to be cancerogenic and cause other health issues. Instead, look for cat food that uses natural antioxidants like vitamin E, rosemary extract, or citric acid. Additionally, food colors are added to cat food to satisfy aesthetic needs, but these compounds are unnecessary and unwanted additions to the cat food.