ECONOMICS OF THE FISHERIES 335 



in sickness and health, and under various dimates and conditions of life, re- 

 finements, balancing and possible improvements in the details of diet with 

 which the science of nutrition is concerned. For our purposes it is sufficient 

 to note that there is little room for any voluntary expansion or contraction of 

 the total with more or less money, income, or pressure of advertisement; it 

 is fixed by the basic requirements of the human body as a machine, and there 

 is little cause to wonder at the constancy in the national figures of food con- 

 sumption as shown in the table. 



Not only is this true of the gross quantity of food, but also of its individual 

 components. The human body on the average requires a minimum of about 

 70 gm of protein per day, of which ten essential amino acids must be present 

 in certain required amounts, also minima of fats and carbohydrates, iron, 

 calcium, etc., as well as of several vitamins. On examination in detail of the 

 historical record above referred to, it will be found that with little or no con- 

 sciousness on the part of individual consumers, their choices of foods over 

 the years add up and balance out so as to provide a very close approximation 

 to the total amount, the energy content and the individual components which 

 the body requires under the prevailing circumstances of life. Of the thousands 

 of plants and animals on the earth which man might cultivate and domesticate 

 for food, he has narrowed the list down to a few hundred (or a few dozen for 

 the bulk of it), and of these few, his selections from day to day meet, with 

 remarkable exactness, the basic requirements of his body. Change and im- 

 provement in diet, projected by scientific research in nutrition, are concerned 

 with remarkably small differences between what is and what might be con- 

 sumed, and these changes, as we shall see, are effected only by long continued 

 pressure against great resistance and inertia. 



The above study by Cavin and Burk is based on the situation in the 

 United States; in all countries the total per capita requirements for energy 

 and nutritive elements vary but little, but the total gross weight, being 

 dependent on the kinds of food which make up the bulk, probably varies 

 somewhat from country to country (Harper, 1945). In some parts of our 

 country and to a considerable extent in some of the poorer and densely 

 populated countries, the diet is in greater part the cheaper cereals, beans, 

 rice, potatoes, and vegetables; in richer ones, the more expensive meats, 

 poultry, dairy products, eggs, and fruits. In any country the shift may be 

 toward higher or lower money value quality with prosperity and depression 

 and with the income and education of the individual. ^^ The total amount of 

 food, of course, increases with increase of population. 



21. For data and discussion of food consumption by families of different income levels, in city, 

 town, country, regions, etc., see Food and Life, U. S. Dept. of Ag., Yearbook of Agriculture, 1939, 

 especially Stiebling and Coons, Present Day Diets in the United States, p. 295-320, Yearbook 

 Separate No. 1682 ; Sherman at al., 1944, How Families Use their Incomes, U. S. Dept. of Ag. 

 Misc. Pub. No. 653. 



