Article #3: Excerpts From Nutritional Methods Of Blood Regeneration, Part II by Dr. R.W. Bernard

Sherman emphasizes the "protein-sparing" action of carbohydrates, and also refers to the synthetic formation of protein within the body by the formation of simpler amino acids, as analine, by union of glucose with ammonia, a protein metabolic end-product. From the simpler amino acids, he claims that more complex amino acids can be synthesized. An abundance of glucose will therefore aid such protein synthesis within the body, whereas, on the other hand, when there is a lack of carbohydrates and fats, protein molecules will be broken down to yield carbon compounds.

Kayser compared the efficiency of carbohydrates and fats as sparers of protein by observing the effect upon the nitrogen balance of replacing the carbohydrates of the food by such an amount of fat as would furnish the same number of calories. On substituting fat for carbohydrate there was a marked increase of protein catabolism, with corresponding loss of nitrogen from the body; this loss of nitrogen, accompanied by a negative nitrogen equilibrium, increased each day that the fat diet was continued, but stopped as soon as carbohydrates were added to the diet, when the body almost at once began replacing the protein it had lost, although the nitrogen and calories of the food were practically unchanged.

Taliquint, working in Rubner's laboratory, also found that if one-third of the total value of carbohydrate in the diet was replaced by fat, there was an unfavorable influence on the nitrogen balance, causing a small fall of body protein. Sherman, in his "Chemistry of Food and Nutrition," says: "It appears that the carbohydrate of the food cannot be entirely replaced by an equal number of calories in the form of fat without an unfavorable effect upon the nitrogen balance."