APPENDIX. 



SUGGESTIONS AS TO METHOD FOR STUDYING THE EFFECT UPON 

 BASAL METABOLISM OF INGESTION OF FOOD OR DRUGS. 



In reporting the results of these investigations on the effect of the ingestion 

 of food upon the metabolism, it seems appropriate, in view of our experience 

 with various foods and numerous subjects during the past 12 years, to offer 

 suggestions as to the methods to be employed for an ideal study of this prob- 

 lem. These suggestions are based not only upon the actual work here re- 

 ported, but also upon much experimenting carried on since most of this work 

 was done. 



Objects. We must first recognize the objects of such a study. These are 

 the determinations of (1) the total effect upon the metabolism of the ingestion 

 of food, namely, the increase above the basal metabolism; (2) the highest 

 increase above the basal metabolism and its 1 time relation to the taking of food, 

 i. e., the peak effect; and (3) the subsequent character of the metabolism to 

 note whether it remains unaltered or if there is a change in the proportions of 

 protein, fat, and carbohydrate metabolized. 



Subjects. It is obvious that the subjects selected should be primarily 

 normal, healthy individuals, without tendency to digestive disturbances. 

 Only through a knowledge of the metabolism of normal individuals can we 

 gain information as to the abnormalities in the metabolism after food inges- 

 tion under pathological conditions. Individuals who are likely to continue 

 throughout an entire series of tests are to be preferred, as they may be 

 depended upon for subsequent duplicate and control experiments. Repeated 

 experiments with the same individuals obviate the necessity for training new 

 subjects, lead to an improvement in the experimental routine, and reduce the 

 number of subjects required for obtaining results which will supply definite 

 conclusions. The training of pathological subjects is more difficult than the 

 training of normal subjects; moreover, the physical condition of such subjects 

 is liable to variation. A greater number of experiments is accordingly neces- 

 sary for a series of investigations with pathological conditions. 



Basal metabolism. Since the object of any study of the metabolism subse- 

 quent to food ingestion is to determine the effect upon the basal metabolism, 

 i. e., the metabolism in the post-absorptive condition (12 hours or more after 

 the last food ingestion) , it is necessary first to obtain an accurate measure of the 

 basal metabolism. As our own unfortunate experience only too frequently 

 shows, it is imperative to determine the basal metabolism and the metabolism 

 after food upon the same day, save perhaps in exceptionally prolonged experi- 

 ments. When this is not done the basal metabolism determined on another 

 day may be higher than the true basal metabolism of the food day, thus lead- 

 ing to the conclusion that the effect of the food is negative. Furthermore, 

 there should be a preliminary period of observation which should be con- 

 tinued 30 minutes or preferably longer, so that one may state with certainty 

 that the basal level has been reached before the actual measurements are 

 begun. During this preliminary period the subject should be at rest and in 

 the same body position as during the experimental period. 



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