492 SYMPOSIUM ON FOOD PROBLEMS 



for protein, or for any individual element, in grams per man per 

 day. The " vitamine " requirement cannot be stated in terms of 

 actual weight either of "fat-soluble A" or of "water-soluble B," 

 but the percentages of certain foods, rich in the one or the other 

 or both of these dietary essentials, which suffice to make an other- 

 wise satisfactory diet adequate for normal growth and reproduction 

 in laboratory animals have been determined for a sufficient number 

 of cases to enable us to take account of this factor of food value in 

 considering the prominence which should be given to each type of 

 food in planning an adequate and economical diet. 



The quantities of nutrients required for normal nutrition as 

 determined by laboratory experiments may be compared with the 

 average quantities actually consumed in typical American dietaries, 

 to find whether our ordinary food ha'bits ensure us reasonable and 

 proportionate margins of safety with reference to each nutritive 

 requirement — in other words a diet well balanced from the stand- 

 point of our present knowledge of nutrition, the older and simpler 

 criteria of balanced diet having now been outgrown. 



If in addition to such a comparison of actual nutritive require- 

 ments with the quantities of nutrients furnished in the usual food 

 supply, we take account also of the kinds and amounts of the in- 

 dividual articles or types of food and the relation which each bears 

 to the whole amount of food consumed, both as regards its cost 

 and its contribution to each of the elements or factors of food 

 value, we shall be able to judge with considerable confidence the 

 nutritional significance of such a shifting of food habits as is con- 

 templated in the program of the Federal Food Administration. 



Most prominent in this program is the saving of wheat. 



By people of comfortable income, wheat-saving may be accom- 

 plished by simple reduction in the amount of bread consumed. 

 The bread thus withdrawn ffom the diet of the well-to-do may or 

 may not be replaced by perishable food depending upon whether 

 or not it is necessary or desirable to keep up the calorie value of 

 the diet, and the weight of the body. In either case the ration with 

 the reduced allowance of bread will usually be as well balanced 

 as before. 



But among those who must consider the cost of their food, the 



