Perspectives in Biology and Medicine

DIFFERENTIAL NUTRITION—A NEW ORIENTATION FROM WHICH TO APPROACH THE PROBLEMS OF HUMAN NUTRITION ROGER J. WILLIAMS and DONALD R. DAVIS* "Differential" nutrition is that which is based on the best scientific information we have regarding our foods and the biological makeup of the people who eat them. In the early twentieth century, there was no such thing as differential nutrition. Nutrition was based on one prime consideration—the composition of the food consumed. The rest of the story was taken for granted. The people who ate food were assumed to be normal, and, after eating, their bodies presumably did with the food whatever was normal and necessary to maintain life. This idea of "normality" has persisted in the field of nutrition decade after decade in spite of scientific advance. As late as 1980 the Food and Nutrition Board listed Recommended Dietary Allowances for "most normal persons" and for "practically all healthy people in the U.S.A." Actually, however, nutrition has come to be seen as based on two prime considerations—the composition of the food, and the genetic makeup of the individuals who consume it. The net benefits of nutrition depend fully as much on how the individual metabolizes the food as it does on the composition of the food itself. Therefore, these are the basic elements of practical nutrition—food composition and individual metabolism . Differential nutrition encompasses both of these prime considerations ; traditional nutrition focuses on only one—food composition. Before nutrition can move into the twenty-first century, it must catch up with a momentous discovery about people and their individuality that is being made in the latter half of the twentieth century. The biological character and makeup of people at the beginning of the twentieth cen- *Clayton Foundation Biochemical Institute, University of Texas at Austin, Austin, Texas 78712.© 1986 by The University of Chicago. AU rights reserved. 003 1 -5982/86/2902-0480$0 1 .00 Perspectives in Biology and Medicine, 29, 2 ¦ Winter 1986 \ 199 tury were about the same as now, but our comprehension of people is undergoing a revolution. About 1900, when nutrition began to be a matter of serious scientific interest, it was supposed that most people (with rare exceptions) had normal metabolism and, therefore, had normal nutritional needs. Sir Archibald Garrod at that time called attention to four inborn errors of metabolism—albinism, alkaptonuria, cystinuria, and pentosuria. Individuals who had these conditions were regarded as freaks of nature and were the rare exceptions that proved the rule of normality. In the light of modern genetics, the fact is that, in the general population , individuals who possess complete, comprehensive normality are so rare as to be practically nonexistent. A substantial part of our knowledge about individuality lies in the field of anatomy. Barry J. Anson, anatomist at Northwestern University Medical School, compiled much of this information after a long period of painstaking research. In his book [1] he registers a very large number of potentially significant anatomical variations in the general population—sizes and shapes of organs and endocrine glands, organ positions, muscle patterns and attachments, tendon patterns and attachments, blood vessel patterns, etc., etc. It is obvious from the contents of Professor Anson's Atlas that there is no such thing as a single model or detailed design of the human body (male or female) that can be used as a basis for judging anatomical normality. Professor Anson, with his expertise, would never say in any circumstance, "This human body is normal in every respect." Rather, he might well say, "There is no such thing as a perfectly formed, normal human body." Professor Anson was not inclined to interpret or philosophize about his findings. He regarded himself as simply an anatomist with a commitment to present the facts of anatomy. The absence of comprehensive normality in the general population was reinforced by R. J. Williams's book, Biochemical Individuality [2], in the broad areas of biochemistry and physiology, including pharmacology and endocrinology. Most important of all in connection with this discovery (of the facts of individuality) was a series of editions, from 1960 to 1983, of The Metabolic Basis ofInherited Disease [3]. This book contains unequivocal information about thousands of...