A Statistical Analysis of the Food Requirements for the Population of the United States
The subject of food and food requirements is of perennial interest both because food is a primary necessity of life and because it is our chief agricultural product. But in times like these the matter has special urgency. Individual families, and the agencies assisting them, want information on food selection in order to safeguard health and efficiency. Economists and administrators need a sound basis for setting goals in agricultural production. In neither of these problems can we depend solely on present food consumption habits for guidance. We would not wish to ignore what may be learned from long established food customs representing the accumulated experience of the race, but we must make use of the knowledge of human food requirements which the scientific research of recent years has given us. The results of this research would scarcely justify placing too great reliance on empirical human experience in matters dietetic. In guiding consumer choice and in adjusting production and distribution to meet it, we should consider what constitutes a desirable regimen, according to our best knowledge of food and nutrition. For many years chemists and physiologists interested in nutrition have been studying the human requirements for food. According to our present knowledge, diets that yield the proteins of good quality, the essential minerals and vitamins, as well as the necessary energy-yielding food must contain between 35 and 40 distinct chemical entities, none of which are manufactured by the body, and none of which can be used interchangeably. Fortunately for those who plan diets, many of these nutrients are so widely distributed in common food materials that there is little danger of shortage in freely chosen diets. On the other hand, some are very unevenly distributed, and unless care be taken in food selection, will be meagerly supplied. The actual amount of each nutrient needed, together with the proportion of each in the diet, has been and still is the subject of many investigations. We have learned much about the demands which the body makes for different nutrients at different stages of development, and how size, sex, and the intensity of muscular activity affect food requirements. There are, of course, wide variations in the requirements of individuals and wide variations in the composition of food materials as eaten. The latter are due in part to variable conditions of culture, and in part to varying methods of handling and cooking. Hence it is very important that we do not hew too close to the mark in translating our knowledge