942 NUTRITION AND HEAT REGULATION. 



On comparing these diets it will be observed that in per- 

 forming hard muscular work the diet contained 1700 Calories of 

 energy beyond that used when no work was done. About six- 

 sevenths of this increase was provided for by the carbohydrates 

 and fats. It will be seen also that in this case the proportion 

 of the total energy obtained from protein remained practically 

 unchanged. 



Mankind is guided and has been guided in all times by 

 the control of the appetite, using this term in a general sense to 

 designate the conscious desire for food, and also the desire, more 

 or less clearly recognized, for special kinds of food. If scientific 

 experiments indicate that this regulatory apparatus leads us to 

 ingest more food than is actually required for the assimilation 

 needs and the energy needs of the body, it remains for observa- 

 tion and experiment to determine whether this excess is beneficial 

 or useless or, perhaps, even harmful. 



Munk gives an interesting table showing how much of certain 

 familiar articles of food would be necessary, if taken alone, to supply 

 the requisite daily amount of protein or non-protein material; his 

 estimates are based upon the percentage composition of the foods 

 and upon experimental data showing the extent of absorption of the 

 foodstuffs in each food. In this table he supposes that the daily 

 diet should contain 110 gms. of protein = 17.5 gms. of N, and non- 

 proteins sufficient to contain 270 gms. of C: 



FOR 110 GMS. PROTEIN ^ n r> n 

 (17.5 GMS. N). FoR 27 GMS - u - 



Milk 2900 gms. 3800 gms. 



Meat (lean) 540 " 2000 " 



Hen's eggs 18 eggs. 37 eggs. 



Wheat flour 800 gms. 670 gms. 



Wheat bread 1650 



Rye bread 1900 



Rice 1870 



Corn 990 



Peas.., 520 



1000 



1100 " 



750 " 



660 " 



750 " 



Potatoes 4500 2550 



As Munk points out, this table shows that any single food, if taken 

 in quantities sufficient to supply the nitrogen, would give too much 

 or too little carbon and the reverse; those animal foods which, in 

 certain amounts, supply the nitrogen needed furnish only from one- 

 fourth to two-thirds of the necessary amount of carbon and, vice 

 versa, the vegetable foods if taken in sufficient quantity to supply 

 the carbon would not give sufficient nitrogen, or if used alone to 

 furnish the requisite nitrogen would give an excess of carbon. 

 This same fact is illustrated in another way in a table compiled 

 by Cohnheim.* To furnish the body with its necessary daily 

 * Cohnheim, "Die Physiologic der Verdauung und Ernahrung," 1908. 



