In 2006, the National Research Council (NRC) of the National Academy of Sciences published an update on the nutrient requirements for dogs and cats. The document makes recommendations as to how much of each nutrient should be included in the diet to maintain health in normal dogs and cats and reviews studies in which the recommendations are based. Thus, the NRC recommendations remain the best available resource for published evidence as to how much of each nutrient should be included in the diet to prevent disease.