RELATIVE VALUES OF FOODS.
How to Regulate our Diet.
Our food must contain certain elements, and in proper quantity, if the body is to be well sustained, renewed and nourished. These are mainly as follows:
1. Protein to form flesh, build muscle, and produce strength.
2. Fat and Carbohydrates, to provide heat and energy.
3. Salts and minerals (such as phosphates, lime, iron, citrates, etc.) to build bones and teeth, feed the brain and nerves, and purify the body.
No hard-and-fast table or rule can be laid down concerning the proper proportions in which these elements should be combined, because the amount needful for each individual varies according to his size, the sort of work he does, the amount of physical or mental energy he puts forth, and the temperature of the atmosphere surrounding him.
Until Professor Chittenden made his extensive and conclusive series of experiments in America, in 1903-4, to determine the real amount of Protein and other elements required to keep the body in perfect health, the average estimate for a person of average size, who does a moderate amount of physical labour, was about 4-ozs. of Protein per day.
But these official experiments, conducted with scientific precision, extending over a long period, and made with thirty-four typical and carefully graded representatives of physical and mental work, demonstrated that half this amount of Protein is sufficient, and that strength and health are increased when the quantity is thus reduced; also that a smaller amount of Carbohydrate food (bread, etc.), than was previously thought necessary, is enough.
One may therefore now safely reckon that men of average size and weight (say 10 to 12 stone) doing a moderate amount of physical and mental work, can thrive under ordinary circumstances on a daily ration containing about 800 grains of Protein (nearly 2 ozs).