Let us take the case of an average-sized man engaged in light work. An average menu for one day for such a man might be as follows: Bread, one pound (453.6 grams); lean meat, half a pound (226.8 grams); oysters, half a pound (226.8 grams); cocoa, one ounce (28.3 grams); milk, four ounces (113.2 grams); sugar, one ounce (28.3 grams); butter, half an ounce (14.17 grams). If one were to tabulate these food materials under three columns, multiplying the number of grams of bread by the percentage of protein, of fat, and of carbohydrates, arranging the results in columns under protein, fat, and carbohydrates, similarly for each food, he would find a total of 106.8 grams of protein in a day's menu, 57.97 grams of fat, and 398.84 grams of carbohydrates. To find the energy value of such a day's menu one has only to multiply the protein by 4, the number of calories per gram of protein; the fat by 9.4, the number of calories per gram of fat; and the carbohydrates by 4. This sums up a total of 2,566.78 calories in the day's menu.

It must be evident that a menu containing approximately this energy total could be arranged from almost innumerable different combinations of foods. In the arrangement of a menu the total protein has usually not been allowed to fall below 100 grams per day, or a little over 3 ounces of dry proteins. The fat has usually not been allowed to fall much below 60 grams (2 ounces) per day, and the carbohydrates to approach 400 grams (13 ounces) per day. The total calories for a man at light, indoor work should not fall below 2,500 calories; it is more usual to have it approach 3,000.

However, researches made by Professor Chittenden, of the Sheffield Scientific School, Yale University, have shown that, at least so far as the protein is concerned, the fuel value can be considerably reduced. His experiments carried through on three groups of men - a squad of soldiers from the United States Army, a group of athletes from the Yale athletic team, and a group of faculty men - all showed the same thing - namely, that the amount of protein can be reduced considerably below 100 grams per day without disturbing the nitrogen equilibrium, and without causing any appreciable loss of weight, and certainly without any loss of physical or mental power or efficiency. In the light of these extensive observations of Professor Chittenden, it seems evident that we can safely reduce the protein to sixty grams or two ounces per day dry weight.

When we consider the cost of proteins in the market, and the fact that any excess of proteins over and above the minimum required for the maintenance of nitrogen equilibrium is oxidized in the muscles simply for fuel, it must be evident that beyond the minimum required it is much more economical to use carbohydrates and fats for fuels.

D. Rations For Different Conditions

Rations Varied For Sex And Age