August 15, 19 18] 



NATURE 



465 



STATISTICAL STUDIES OF DIETARIES.-^ 



THE matter which is essentially new in this 

 interesting and valuable report by Viscount 

 Uunlace and Capt. Greenwood is a statistical 

 ■^tudy of the diet of workers fed in hostels and 

 ranteens attached to various factories under the 

 Ministry of Munitions. The document also con- 

 tains an independent analysis of available figures 

 relating to working-class dietaries before the war, 

 and it is prefaced by an exceedingly interesting 

 appraisement of the practical significance which is 

 attached to the results of modern experimental 

 work on dietetics. 



A careful study of food consumption under the 

 conditions of canteen feeding must yield a valu- 

 able document. When, as in the majority of cases 

 dealt with in this report, the whole nourishment 

 of the individual is derived from an official food 

 supply, the data become more trustworthy than 

 those of most statistical studies, and there is the 

 additional merit that individual consumption is not 

 forced or otherwise affected by a predetermined 

 ration such as exists in the Army. A further 

 advantage is that the work done by various sec- 

 tions of the community, though not actually 

 measured, nor perhaps measurable, is at least of 

 a recognisable order of severity. 



The average dally consumption "per man" of 

 some 20,000 munition workers during the spring 

 and summer of 1917 was found to consist of ii5'7 

 grams of protein, I4r3 of fat, and 4o8'4 of carbo- 

 hydrate. The average Calorie value of the food 

 was 3463, a figure very near to the standard so 

 generally accepted for a rtan doing moderately 

 severe work. All the figures refer to food "as 

 purchased." 



The statistical method applied to nutritional 

 studies has obvious limitations as a guide to 

 practice, especially if guidance be sought when, 

 as now, the national conditions are exceptional. 

 Its results display the Influence of appetite limited 

 chiefly by economic conditions. If the latter 

 are unfavourable, statistics of consumption do not 

 guarantee the measure of an efficient diet. If 

 conditions are favourable, the statistics may offer 

 no guidance for economy. In this connection, how- 

 ever, the above data are perhaps more than usually 

 trustworthy. The munition workers were well 

 paid, but in the earlier months of 191 7 there was 

 an atmosphere tending to check extravagance, 

 though as yet there was no feeling that the in- 

 dividual should go actually short. It is Interesting 

 to find, therefore, that the energy consumption 

 was so closely similar to that of the working 

 classes before the war. The average figure for 

 the latter, as re-calculated by the authors from the 

 Board of Trade returns, was 3571 Calories. 



The dietaries of munition workers were, how- 

 ever, in a qualitative sense, abnormal, especially 

 in the very high proportion of fat eaten. In this 

 respect they cannot serve as a model for the 

 present or for the Immediate future. This high 



1 " An Inquiry into the Composition of Dietaries, with Special Reference 

 to the Dietaries of Munition Workers." Medical Research Committee ; 

 Special Report Series No. 13. 



consumption of fat resulted from the circumstance 



that at the time when the statistics were being 



I collected an acute shortage of potatoes co-existed 



j with a vigorous "eat less bread" campaign. In 



I one. hostel, where the "voluntary" weekly bread 



I ration of 4 lb. was literally accepted, the fat con- 



i sumption rose to 214 grams a day! As the 



I authors remark, this is a sufficiently instructive 



instance of what happens when the nutritional 



habits of the population are disturbed by force 



' of circumstances or otherwise. 



I There is great difficulty in choosing a final 

 ! expression for the results of statistical studies on 

 ; the diet of a community. The demands of men, 

 j women, and children respectively have to be 

 I brought to some common denominator. This is 

 usually done by expressing them all in terms of 

 "man value." To take a woman's demands as 

 eight-tenths of a man seems justified by the best 

 data available. Much less satisfactory, however, 

 are the factors hitherto used when growing boys 

 and girls are concerned. To take the require- 

 i ments of boys at thirteen as being 06, and of 

 I boys at fifteen as 07, of a man's (Atwater and 

 j Bryant) is certainly an error. The measurements 

 j of basal metabolism made and collected by 

 I Dubois, for instance, show that the requirements 

 are proportionately high at these ages, so that a 

 boy of thirteen wants little less food than his 

 father, if the latter be a moderate worker. 

 F. Gephard found, indeed, that the consumption 

 at a large boys' school in Concord, New Hamp- 

 shire, was nearly 5000 Calories per head per day. 

 This question is not fully discussed by th* 

 j authors of the report, who, following the Food 

 Committee of the Royal Society, used the Atwater 

 factors.. They show, however. In an appendix, to 

 what an important degree the recognition that 

 the demands of children are larger than was 

 thought will affect current statements as to con- 

 sumption "per man" when family budgets are 

 dealt with. For example, taking the normal 

 family of man, wife, and four children, the man 

 value usually taken is i +0*8 + 4 x 0*51 = 3*84. 

 Taking the factor for children as 07 instead of 

 051, the man value becomes 4'6, and the per 

 caput man consumption is reduced to 83'5 per 

 cent, of its usually tabulated value. At any rate, 

 a proper recognition of the requirements of chil- 

 dren is of immense importance in budgeting for 

 the nation. 



Unfortunately, statistical studies do not tell us 



I what at the moment It is so desirable to know. 



I How far can the customary diet of a community 



j be reduced without reducing its output of work? 



! If reduction in food merely means inconvenience 



! or even a degree of suffering, the nation will not 



fear it. What it has to fear is a consequential 



; diminution In productiveness. 



I Even experimental studies have not yet given 



, a satisfactory answer to the above important 



question. W'e know that if an individual under 



favourable conditions of nutrition will accept with 



equanimity a certain loss of body-weight, he may 



considerably reduce his consumption without 



NO. 2546, VOL. lOl] 



