504 RKl'OUr OK OFFICE OF FXPEKIMFNT STATIONS. 



for the Insano in Wiisliin<;ton, rcquostod llu> cooperation of the Office of 

 ExperinuMit Stations, in connection witii its nutrition investigations, in 

 a study of food iH-ononiy of the institution under his charge. It was 

 his desire to k^arn whether, as judged according to the best avaihiblc 

 knowk'dge, the diet of the hospital was properly suited to the needs 

 of the euiployees and patients, and whetlicr it was being suppliccl as 

 economically as circumstances would warrant; or, if it was at fault 

 in either respect, in what ways it might l)e inij)i()ved. So far as the 

 Office of Experiment Stations was concei'ned the opportunity to assist 

 in such iiHjuiry was considered especially advantageous, both as showing 

 how the results of nutrition investigations maybe put to practical use, 

 and also foi- securing additional data for the establishment of dietary 

 standards and other useful information regarding the dietetics of public 

 institutions, requests for wdiich are being continually received. That 

 the importance of this subject is becoming more widely recognized is 

 manifested b}^ the inquiries that are being made and by the interest 

 displayed by a large and increasing number of officers of public insti- 

 tutions and by public-spirited citizens. 



PRINCIPLES GOVERNING THE PLANNING AND IMPROVING OF 



DIETARIES. 



From the data obtained ))y experimental inquiry and from the facts 

 learned by experience and observation in the feeding of large groups 

 of people, several general principles ma}^ be deduced that must be con- 

 sidered both in the original planning and in the attempt to improve 

 the diet of an institution. A certain amount of food is necessar}'^ for 

 sustaining bodily functions, and this requirement, which is termed 

 the physiological demand, varies with diti'erent conditions such as age, 

 sex, health, muscular activity, environment, etc. The physiological 

 demand forms the ]>asis of the dietary standard, which may be 

 expressed in amounts of food materials, or more conveniently in quan- 

 tities of nutrients and energy, since the nutritive values of all food 

 materials maj^ be stated in these terms. The food supply of the insti- 

 tution must necessaril}^ be larger than is required simplv to meet the 

 physiological demands of the inmates, since it is practicall}' impossible 

 to store, cook, and serve food without some loss from shrinkage and 

 w^aste, the amount of food thus lost depending very largel}' upon its 

 quality and upon the methods of storeroom, kitchen, and dining-room 

 management. To provide adequately for the institution, therefore, 

 the total food supply nnist be large enough to cover both the needs 

 of the population and the losses from shrinkage and waste. The differ- 

 ence ])etween food supply and food consumption, however, should not 

 be unduly large, because when the former is too generous the kitchen 

 and table wastes are likely to be excessive; and where food is served 

 too abundantlv there will also be atendencv to consume more food than 



