98 THE PROTEIN ELEMENT IN NUTRITION 



The extremely meagre clothing of the poorer classes may create 

 a certain demand for easily oxidizable material in the up -keep 

 of the body temperature, particularly during the cold weather. 



The question, therefore, arises : Seeing that a European in 

 a cold climate, doing an average amount of work, can live quite 

 well with 40 calories per kilo of body weight, whilst the Bengali 

 prisoner, in a hot climate, doing the very minimum of work, is 

 provided with 60 to 70 calories per kilo of body weight, what 

 becomes of the great potential energy of the dietaries ? How 

 does he get rid of it ? How is it dissipated ? 



The answer to this question would appear to be threefold. 

 A part of the carbohydrate, varying in amount according to the 

 needs of the body, is absorbed and made use of to supply the 

 energy necessary for the maintenance of body heat and that 

 essential for the work of the body ; a part undergoes little or no 

 change in the bowel, and passes out undissolved. This is prob- 

 ably due to its being bound up with cellulose, so that the digestive 

 juices are unable to penetrate to the starch granules and set up 

 changes essential for absorption. A third part is broken up in 

 the digestive tract by excessive micro-organismal fermentation, 

 which, beginning in the stomach, is contained in the intestines. 

 By this last method a very large percentage of the total potential 

 energy of the diet may be dissipated through the conversion of 

 its starch or sugar into carbon dioxide, methane, hydrogen, acetic 

 acid, butyric acid, etc., and other fermentative products of low 

 caloric value. 



This loss, which may be considerable in amount depending 

 upon the extent of intestinal fermentation, will tend to reduce 

 the fuel value of the diet, and may afford a likely explanation 

 of the remarkable want of body fat in the great majority of the 

 working population of Bengal. So far as we know, there is no 

 method by which this loss can even be approximately computed 

 at least, by chemica means ; but that it is an important factor 

 in reducing the potential value of the food will be readily 

 admitted when it is considered that even with gaol dietaries, 

 which are exceedingly rich in carbohydrates, the storing of fat 

 is practically nil, whilst in the working coolie of Bengal, living in 

 a condition of more or less nitrogen starvation, neither body fat 

 nor properly developed muscular tissues are usually to be found. 



It is evident from the above considerations that the ordinary 

 methods of determining the digestibility and absorption of the 



