The Stuff We're Made Of
( Originally Published 1916 )
Let us inquire into the constituents of the human body. Consider the average man as weighing 150 pounds. His weight is distributed as follows: — 90 pounds, water; 27 pounds, proteins or framework, including muscles and important tissue elements; 22 1/2 pounds, fat; 9 pounds, minerals; and 1 1/2pounds, starch or sugar. Bones are 64 per cent. lime and 33 per cent. gelatin, a kind of protein. Muscle is 15 per cent. albumen, another protein. This shows us that the body framework is largely protein.
Fats, which are principally body reserve, vary considerably in amount. In the individual of ideal weight, they are less than the proteins; in the corpulent, they comprise the greater part of the excess.
One very astonishing fact is that though the carbohydrates in the body (such as sugar or starch) comprise only 2.5 per cent. of the solid constituents, they form between 60 and 70 per cent. of the average diet. They are readily digested and used as fuel. They are utilized about as rapidly as they are eaten. From them is developed most of the heat and energy needed by the body. If they are stored at all in the tissues, it is after they have been converted into fat.
This very short discussion of the body constituents gives the reader knowledge which will enable him to understand the principles used in determining such diets as are hereinafter presented.