130 REPORTS OF INVESTIGATIONS AND PROJECTS. 



NUTRITION LABORATORY * 



F. G. Benedict, Director. 

 The researches into human nutrition which have been carried out by grants 

 from the Carnegie Institution of Washington in the chemical laboratory of 

 Wesleyan University, at Middletown, Connecticut, began with a study of the 

 influence of inanition on metabolism. Though innumerable new problems 

 arose out of this interesting research, the particular form of apparatus then 

 in use was not specifically designed for studying these correlated problems, 

 and hence the important question as to the general influence of the ingestion 

 of food upon metabolism was next studied. 



The classical researches of Rubner on the one hand and Zuntz and his 

 associates on the other have brought to light much interesting data regard- 

 ing the influence of the ingestion of food upon metabolism, the digestive pro- 

 cesses, such as the secretion of digestive juices and the activity of peristalsis, 

 with special reference to the effect upon the heat production and the gaseous 

 exchange in the lungs. The methods employed by these investigators were 

 markedly different, and hence it is not surprising that noticeable differences 

 in the nature and extent of the various phenomena have been reported by 

 the two schools. 



The respiration calorimeter, designed as it is to measure simultaneously 

 the carbon dioxide, water-vapor and heat elimination and the oxygen con- 

 sumption of a man, is especially well adapted to the study of the phenomena 

 incidental to the ingestion of food, and consequently an extensive series of 

 experiments have been made with the view of obtaining new information on 

 this most important physiological process- 

 In such experiments it is necessary to have a "base-line" or standard of 

 comparison to which the various activities may be referred, and by common 

 consent all physiologists have taken for this standard the physiological 

 activity of the body at rest and after a short period of fasting. The impor- 

 tance of knowing more fully the exact nature of metabolism during inanition 

 led to an extended series of observations on fasting men, in which the period 

 of inanition continued from 2 to 7 days. The results of these observations 

 have been published by the Institution as Publication No. 'jj. 



Physiologists, in considering a diet, are wont to recognize not so much the 

 kinds and amounts of food materials ingested as the kinds and amounts of 

 the nutrients contained in the food materials. These nutrients — the protein, 

 fat, and carbohydrate — exist in all food materials in varying amounts, the 

 flesh foods being rich in protein and fat, while as a rule the vegetable foods 

 furnish the greater supply of carbohydrate, such as starch and sugar. Pro- 

 tein and fat of vegetable nature, such as gluten of wheat and olive oil, are, 



* Situated at Boston, Massachusetts. Grant No. 352. $100,000 for purchase of site 

 and construction of building, and for investigations. (For previous reports on work in 

 nutrition see Year Book No. 2, p. xxxix; Year Book No. 3, p. 130; Year Book No. 4, 

 p. 258; and Year Book No. 5, pp. 212-219.) 



