The lack of understanding of the way to solve the practical problems of alimentation which were forced upon Europe by the war is easily appreciated when we consider how new the science of nutrition is. The literature relating to the phases of the subject which were understood was confined to scientific journals. Few of the men who became officials in the armies had any knowledge of nutrition other than that relating to calorific and protein requirements. Under the trying conditions of war there was little time or opportunity to acquire or apply new knowledge, and no great incentive to seek anything beyond bare subsistence except in those members of the population who contributed directly in some manner to military success.

It is not easy to overlook the short-sightedness and to forgive the damaging propaganda of certain specialists concerned with public health work who hold that there is no reason to believe that there is any important relation between the character of the diet and the health of the individual except under circumstances where the faults of the diet are extreme. Some have insisted that the great increase of tuberculosis in Europe since 1914 is no evidence that under conditions more nearly approaching normal, the character of the diet is a factor of importance in predisposing one to this disease. The view is held that at a certain point of severity in malnutrition the vitality breaks down, and the body becomes a prey to diseases due to the invasion of micro-organisms, but that up to this critical point the diet plays little, if any, role in the etiology of infectious diseases. There is much reason to believe that this conception is not generally applicable and that it applies only to a certain group of infections. There are many grades of malnutrition between the optimum well-being on the one hand and on the other, such extreme conditions as are recognizable by the clinician.