MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 263 



When the fuel value of the diet is in excess of the needs of the body, the latter often. 

 though not always, increases its store of material. Sometimes this increase is in the form of 

 protein, sometimes fat, and sometimes both protein and fat. When the body requires energy in 

 excess of that supplied by the food, it will draw upon its previously accumulated store of fat or 

 protein, or both, fur fuel. Along with the gains and losses of protein and fat are changes in the 

 carbohydrates (glycogen), but the total quantity of. these substances in the tissues is relatively 

 small. The present methods of experimenting do not suffice for accurate measurement of the 

 changes of o'lycoevn. and it is commonly left out of account in discussions such as that in which 

 we are now engaged. 



PROTECTION OF BODY FAT. 



The figures for the individual experiments in Table CXX of the Appendix show in some 

 cast's a larger gain or smaller loss of fat without alcohol than with it; in other cases the results 

 are reversed. When, however, the experiments are grouped together and the averages with 

 and without alcohol are compared, it is clear that, except where the differences in fuel value of 

 the diet were considerable, the differences of fat balance are hardly large enough to be of 

 consequence. Taking the experiments altogether, the figures of the tables, and especially those 

 of Table 14, show slight gains in fat both with and without alcohol, but the gain is slightly larger 

 with the alcohol. Thus in Group I. in which the experiments are more directly comparable, the 

 average gain in 9 experiments without alcohol is 1.1 grams, in 6 with alcohol 2.4 grams, making 

 a difference in favor of the alcohol of 1.3 grams. In the less directly comparable experiments 

 there is an average difference of 8.8 grams, and in Group III with all the experiments there is an 

 average of 3.9 grams in favor of the alcohol. It is also to be noted that in general the total 

 energy of the rations with the alcohol average somewhat larger than in those without alcohol. 

 The figures for differences just cited are brought out more clearly in Table 17, beyond, in the 

 discussion of the utilization of energy in the experiments with and without alcohol. The 

 comparison as there made in detail shows on the whole an advantage of the ordinary diet over 

 that with alcohol, though the difference is very small, indeed. 



A direct indication of the fat-protecting power of alcohol is found in the series of experi- 

 ments with E. O.. Nos. 22. 23. 24. These were practically three successive periods of 3 days 

 each. In all there was a basal ration with 116 grams available protein and 2,290 calories of 

 available energy. To this ration was added — in the first experiment, alcohol: in the second, 

 nothing: in the third, sugar. The alcohol and sugar each furnished about 500 calories of energy. 

 With the alcohol there was a daily gain of 63 grams of fat; with the basal ration this was reduced 

 to 9 grams: with the sugar it rose again to 60 grams per day. With the sugar there was a gain of 

 1.7 and with the alcohol a gain of 1.4 grams, while with the basal ration alone there was a loss of 

 1.6 grams of protein. Leaving this slight gain or loss of protein out of account, the net gain of 

 fat with the alcohol above that in the basal ration was 54 grams, which would make very nearly 

 500 calories. The net gain of fat with sugar was ;,i grams. In this particular case, therefore, 

 with isodynamic quantities of sugar and alcohol, the gain of fat was practically the same with 

 both. 



An even more striking illustration of the fat-protectine- power of alcohol is found in experi- 

 ments Nos. 18-21, with A. W. S. as summarized on page 329 beyond. When alcohol was added 

 to a basal ration of ordinary food, the body gained fat at the rate of 21-35 grams per day: but 

 when the giving of alcohol was stopped and the body had only the basal ration, it lost 25 grams of 

 fat pel- day. 



A clearer demonstration of the power of alcohol to protect fat from consumption would be 

 hardly possible than that given in the experiments with E. O. and A. W. S., just cited. 



We thus have two kinds of tests of the power of alcohol as compared with that of isodynamic 

 amounts of carbohydrates and fats of the food for the protection of body fat. In every indi- 

 vidual case the protecting power of the alcohol is manifest. In some instances it is slightly 

 inferior and in others it is slightly superior in this respect, and on the average it is just about 

 equal to the nutrients which it replaced. 



