28 FOOD INGESTION AND ENERGY TRANSFORMATIONS. 



experiments were carried out with one subject. An extensive list of 

 basal values is reported, these values being, for the most part, very 

 constant. Since it is necessary to consider the time element in experi- 

 ments of this kind, Magnus-Levy carefully determined the basal metab- 

 olism throughout the day on three subjects and found it relatively 

 constant, the values for the oxygen consumption falling approximately 

 5 per cent during the day. 



Food experiments were made on 3 days with fat, the diet on one day 

 being 210 grams of bacon, 30 grams of bread, and 8 c.c. of alcohol; on 

 another day 210 grams of butter; and on a third day 100 grams of 

 bacon. A small increase in the metabolism was noted, particularly 

 in the later hours. In the first two experiments the increment in the 

 oxygen consumption was from 10 to 14 per cent. In the last experi- 

 ment the maximum value was but 6 per cent above the basal value. 



In carbohydrate experiments carried out with four subjects, white 

 bread was chiefly used, but one experiment was also made with pumper- 

 nickel. The increment in the oxygen consumption was positive in 

 practically all cases. It was found that the increment in the first 

 hour may be as high as 33 per cent; in three cases it was over 6.5 per 

 cent even 7 hours after taking food. Eight experiments were made 

 on man after giving from about 50 to 155 grams of cane sugar or grape 

 sugar. The oxygen consumption, which alone may be used in meas- 

 uring the increase in the total metabolism, showed in all but one 

 case an increase during the first hour, this increase amounting in one 

 instance to 16 per cent. In subsequent hours the values were fre- 

 quently below the basal value, particularly when small amounts of 

 sugar were given. With 100 or more grams of sugar oxygen values 

 above basal were found; in one experiment the increment persisted 

 for 8 hours. 



Five observations were made on man after roast beef had been given 

 in amounts varying from 120 to 310 grams. In all of the experiments 

 the percentage increase in the oxygen consumption was very marked, 

 the maximum occurring between the third and sixth hours. In at 

 least three instances the increment was 20 per cent or over as late as 

 the seventh or eighth hour, showing a marked and prolonged effect 

 as a result of the ingestion of protein. 



Three experiments were made in which the subject took a mixed 

 diet which supplied 3,060, 2,280, and 2,150 calories, respectively. In 

 practically all instances about 47 per cent of the energy came from 

 carbohydrate, 33 per cent from fat, 14 per cent from protein, and 6 

 per cent from alcohol. The increase in the oxygen consumption 

 was marked in nearly every case. Thus, after breakfast, the average 

 percentage increments for 4 successive hours were 27, 27, 16, and 6 per 

 cent, respectively; after the noon meal for 6 successive hours they were 

 40, 35, 27, 19, 17, and 9 per cent, respectively; after the evening meal 



