Whither Nutrition?

Our present knowledge of nutrition is largely based on the enormous number of important discoveries which were made in the first 40 years of this century. During that time, it was recognized that about half the amino acids, which are present in proteins, are essential: that is, they cannot be made in the human body from the digestive form of nitrogen and readily available carbon sources. Almost all the vitamins were defined during this period, and their structures, which cover a great variety of types, were established. We also learned during this period that many of the vitamins are either themselves co‐factors of enzymes, or can be modified in the body in such a way as to act as co‐factors. We also learned to realize that some fatty acids are essential; in other words, they have to be supplied in the diet as such and cannot be derived metabolically from other fatty acids. We derived some ideas of the amounts of these various substances which are required by the growing child, the pregnant mother, and the adult. In addition, we had some information of the mineral requirements, such as iron and calcium, and our knowledge was sufficiently comprehensive to enable the country to devise a food policy which was remarkably effective. In fact, it has been stated that the population of the United Kingdom has never been so well fed as it was during those difficult years of the Second World War.