FOODS AND FEEDING 65'6 



Carbodydrates do not directly furnish tissue elements, 

 but do so indirectly in preventing decomposition (to some 

 extent) of protein in the body, and in lessening its consump- 

 tion. In this way the comparatively inexpensive carbohy- 

 drates will compensate for an insufficient ration of costly 

 proteids. 



It is asserted that this action of carbohydrates is 

 explained by the fact that these nutrients have a greater 

 affinity for oxygen than proteids and so are the first to undergo 

 combustion. 



The term albumenoid was formerly used as synonymous 

 with proteid, but is now employed to include nitrogenous 

 bodies (gelatin) derived from protein in the body but not 

 convertible into proteids. These bodies do not take the 

 place of proteids, but appear to fulfil the functions of circu- 

 lating protein, and, like carbohydrates, conserve protein 

 consumption, but are not tissue builders. 



Carbohydrates aid directly in the production of fat. 

 Fat in the food may be directly assimilated as such if there 

 is a sufiicient carbohydrate and proteid ration to protect it 

 from decomposition. The role carbohydrates play includes : 



1. The formation of tissue indirectly by protecting the 

 proteid elements from combustion with an insufficient 

 nitrogenous diet. 



2. The generation of heat, energy, or mechanical work. 



3. The production of fat. 



Carbohydrates cannot be relied upon as sole articles of 

 food. The fat of the body is derived from the decomposition 

 of proteids and carbohydrates, and directly from fat con- 

 tained in the food. Fat lubricates the tissues, and a reason- 

 able accumulation serves as a store of potential energy to be 

 called upon in time of need, when its action is similar to that 

 of carbohydrates. The main source of muscular energy, 

 movement, or mechanical work, is thought to reside in the 

 carbohydrates, because with excessive muscular work there 

 is increased evolution of heat, carbonic dioxide and water. 

 In so far as muscular energy and power depend upon a good 



