Few aspects of human behavior are characterized by more ethnocentrism than a group's dietary habits and practices. People around the world usually tend to assume that their foods are the most tasty and the most nutritious. Often such beliefs find expression as dietary prescriptions for others. Here the assumption is "because we find these foods 'tasty' and nutritious, you should also." Such beliefs, of course, could not be farther from the truth, and in an article to appear later this year in the anthropological journalCurrent Anthropology, I have reviewed evidence from several disciplines which seems to indicate that (1) Westerners, despite the trappings of civilization, are not free from such biases; (2) racial-cultural groups differ greatly in their ability to benefit nutritionally from certain foods, in particular milk and many milk products; and (3) such differences can be accounted for in terms of a model dealing with the interaction