34 VITALITY AND EFFICIENCY WITH RESTRICTED DIET. 



between complete fasting and chronic or partial inanition. The liter- 

 ature on complete fasting is fairly abundant and emphasizes sharply 

 the fact that a complete fast is frequently accompanied by acidosis. 

 This acidosis, it is believed, stimulates the cells of the fasting organism, 

 producing a somewhat higher metabolism than might otherwise exist. 

 Hence the subject of complete inanition is hardly touched upon in our 

 citation of the literature. 



Temporary complete absence of food from the stomach must not, 

 however, be confused with complete fasting. As has been shown, the 

 ingestion of food produces a definite effect upon metabolism. Any 

 food in the stomach results in an increased heat production, food inges- 

 tion being second only to muscular work as a factor for producing an 

 increase in the metabolism above basal. In looking over the literature 

 on the subject of metabolism during undernutrition, one finds only too 

 frequently that confusion has arisen from the fact that writers have 

 included in the basal measurements the excess metabolism due to the 

 stimulus of food. The instances are rare in which clear-cut evidence 

 is given regarding the basal metabolism at different nutritional levels, 

 for obviously an experiment which includes the activity incidental to 

 food ingestion can throw but little light upon the actual basal require- 

 ments. It is quite probable that this practice is due in large part to the 

 original conception of Rubner that when food is given below the main- 

 tenance requirement the so-called specific dynamic action of food does 

 not appear.^ Modern experiments have shown that this is not the 

 case and that the ingestion of food always stimulates metabolism. 



For accurate comparative measurements it is possible to use only 

 those values obtained when the subject is in complete muscular repose 

 and when there is no food in the alimentary tract, i. e., with men usually 

 12 hours after the last meal, the so-called ''post-absorptive condition." 

 On the other hand, the use of basal values obtained in one, two, or 

 more days of complete fasting is distinctly erroneous. All of the 

 earher discussions of the influence of partial nutrition upon the basal 

 metabolism, which use basal values obtained on days of complete 

 fasting, must therefore be considered as fundamentally incorrect. 



The evidence on the gaseous exchange during undernutrition, as 

 found in previous literature, is very conflicting. No better illustra- 

 tion of this uncertainty can be given than to point out the fact that 

 writers may interpret exactly the same data in two strikingly different 

 ways. Thus we have already shown that the data obtained by Falta, 

 Grote, and Staehelin^ are, in our judgment, not justifiable as proof of a 

 depression in metabolism. On the other hand, the metabolism meas- 

 urements on Caspari's vegetarian,^ according to Staehelin,* show no 



1 Rubner, Zeitschr. f. Biol.. 1883, 19, p. 348. 



2 Falta, Grote, and Staehelin, Beitr. z. chem. Physiol, u. Path., 1907, 9, p. 333. 

 « Caspari, Arch. f. d. ges. Physiol., 1905, 109, p. 473. 



* Staehelin, Deutsch. med. Wochenschr., 1909, 35, p. 610. 



