NUTRITION LABORATORY. 247 



of the daily caloric requirements of a normal infant may be made by adding 

 to the basal metabolism the calories used by muscular activity. If the 

 infant is very quiet, 15 per cent of the basal metabohsm should be added, 

 if normally active 25 per cent, and if extremely active about 40 per cent. To 

 the result add 15 per cent for energy lost in the excreta and 20 per cent for 

 groAvth. By this method of calculation it is estimated that the daily food 

 requirements of the two infants studied are about 100 calories and 94 calories 

 per kilogram of body-weight respectivel3^ It is probable that infants fed on 

 cow's milk, particularly on formulas containing large amounts of protein, will 

 require even more food than infants fed on human milk, because the stimu- 

 lating action of protein causes extra heat to be produced during digestion. 



(7) Food ingestion and energy transformations with special reference to the stimulating 

 effect of nutrients. Francis G. Benedict and Thome M. Carpenter. Carnegie 

 Inst. Wash. Pub. No. 261. (In press.) 



This publication reports the results of an extensive series of observations 

 with human subjects on the influence of the ingestion of food upon metab- 

 ohsm. During a period of some 10 years (1904-1915) data for the research 

 were secured, first at Wesleyan University, Middletown, Connecticut, with 

 the respiration calorimeter, and subsequently at the Nutrition Laboratory, 

 Boston, Massachusetts, with the chair and bed calorimeters and two forms of 

 respiration apparatus — the universal respiration apparatus and Tissot res- 

 piration apparatus. 



Following an historical review of all previous investigations with man 

 relating to food ingestion and energy transformations, an extended discussion 

 is given of the necessity of establishing a suitable base-hne upon which may be 

 superimposed the factor of the ingestion of food. A critical examination is 

 made of those factors liable to influence the determination of the basal metab- 

 olism, as muscular activity, sleep, condition of fasting, growth, climate, 

 temperature environment, etc.; the advantages and disadvantages are con- 

 sidered of the three types of basal periods employed (basal periods of 24 hours' 

 duration, of approximately 8 hours' duration, and of approximately 15 min- 

 utes' duration) ; the use of average basal values is likewise discussed. 



Measm-ements of carbon-dioxide production, oxygen consumption, and 

 heat-production, and in numerous instances records of pulse-rate, respiration- 

 rate, and blood-pressure, were obtained with 39 male subjects in about 190 

 experiments. Studies were made of metabolism during chewing and after 

 the ingestion of water, coffee, beef tea, and single food materials in which 

 carbohydrate, fat, or protein predominated. A number of experiments 

 were also made with combinations of food materials. 



The conclusions drawn from the various groups of experiments may be 

 summed up as follows: 



1. The work of mastication, such as would be involved in chewing gum or 

 a rubber stopper continuously, may temporarily require an increment in heat- 

 production of approximately 17 per cent. 



2. Ingestion of water with a temperature of either 22° C. or 55° C. produces 

 no significant increment of the basal metabolism, if not over 500 grams of water 

 are taken. With larger amounts of cold water there may be an increase 

 which, in certain instances, has been found to amount to 16 per cent above 

 the basal value. 



3. Coffee, owing probably to its caffein content, acts as a stimulus to the 

 metabolism. Approximately 325 grams of coffee at a temperature of about 

 60° C. will produce an increment in the metabohsm of 8 to 9 per cent. 



4. Beef tea, taken either hot or cold, slightly increases the metabolism. 



