Nutrient density: an important and useful tool for laboratory animal studies.

Nutritional deficiencies or imbalances are suspected contributory factors to several types of human cancers, and perhaps other human diseases related to long-term metabolic derangements. In order to study these more effectively in laboratory animals, it is suggested that the laboratory diets more closely mimic the nutrient density of suspect human diets. Toxicology and carcinogenic data obtained in animal study using diets based on human nutrient density might be more readily applicable in relation to humans.