414 ISIDOR GKEENWAID 



amounts these are required we do not know. It is possible that these 

 amounts will he found to vary considerably with the nature and amount 

 of other constituents of the diet. Some evidence that this is so is already 

 available. For a further discussion, the reader is referred to the chapter 

 011 vitamins. 



Undernulrilion 



* 



For years it has been known that fasting reduces basal metabolism but 

 the significance of this fact as indicating a means of lowering the level 

 of metabolism does not appear to have been fully appreciated until after 

 the outbreak of the war. Then it was noted, particularly in Germany, that 

 large numbers of people maintained themselves in good health and remained 

 capable of performing their accustomed tasks while eating much less food 

 than they had previously. They lost weight but not continuously and the 

 loss was slight in comparison with the saving in food effected. The energy 

 content of the food of the city population was probably about 2500 calories 

 per man per day, but was increased by means of extra rations for those 

 working in factories, mines, etc. (though still remaining below the accus- 

 tomed quantity) and by extra foods purchased openly or surreptitiously by 

 those whose means permitted them to do so. 



Loewy and Zuntz showed that this maintenance at a lower level was 

 duo to lowered basal metabolism and not merely to the reduction in the 

 protein of the food. 



The success of the German people in maintaining health and vigor on 

 such low diets appeared so striking that it seemed almost a foregone con- 

 clusion that their previous food intake had been greatly excessive. 



In this country, Benedict, Miles, Koth and Smith, in a series of experi- 

 ments, found that a group of twelve young men w r hose usual requirement 

 of food was 3090 calories per day lost weight when placed upon a diet fur- 

 nishing only from 1600 to 1800 calories, until after five weeks they had 

 lost 10.5 per cent of their body weight. Thereafter, without changing 

 the character of the food from that to which they were accustomed, they 

 wero furnished an average of 1967 calories, upon which the body weight re- 

 mained stationary for a period of several months. Examination, by IfcCol- 

 luin, of the diet furnished these men showed that it was not deficient in any 

 known dietary constituent but only in total energy content. At first it 

 seemed as if this economy in food was accomplished without any untoward 

 effect but as the experiment continued it became evident that the men were 

 not capable of the physical exertion that had previously been readily dis- 

 played. They lacked spirit and were easily tired. To use a colloquialism 

 which many of them used to describe their condition, they lacked "pep." 

 There was no clear evidence of lack of mental power but there was a very 

 decided lessening of sexual desire. 



