"Wear and Tear" Protein

To the Editor:—  In the article, "Nutrition in Chronic Renal Failure," in The Journal, June 25, 1960, page 905, Dr. A. J. Merrill, in discussing protein metabolism in chronic nephritis, states as follows: "Estimates by authorities vary from almost no protein content in the butter-sugar-cornstarch diet of Borst, to 20 Gm. of protein per day in the rice diet suggested by Kempner, and 1 Gm. of protein per kilogram per day in the diet as suggested by Burnett.... The minimum for wear-and-tear replacement is 0.5 Gm. of protein per kilogram of body weight.... Raising carbohydrate intake above 100 Gm. in normal subjects failed to produce much more protein-sparing action in six to eight days than the 100 Gm. carbohydrate diet."An intake of 0.5 Gm. of protein per kilogram of body weight per day does not represent "wear-and-tear" protein. The term "wear-and-tear" quota of protein was coined by Rubner to