WEIGHT IN GRAMMES
CONDITION Proteid Fat Carbohydrates
Child up to 1-1/2 years (average) 0.71-1.27 1.06-1.59 2.12-3.18
Child from 6 to 15 years (average) 2.47-2.82 1.30-1.76 8.82-14.10
Man (moderate work) 4.16 1.98 17.63
Woman (moderate work) 3.24 1.55 14.10
Old man 3.53 2.40 12.34
Old woman 2.82 1.76 9.18
Atwater (man, light exercise) 3.70 3.70 13.3
Chittenden (man, light exercise) 2.16 2.83 13.0

A well-designed food ration, therefore, will be one which will provide the body with the proper amount of food material wisely adjusted to the occupation and the digestive ability of the individual. It has been, in the past, a matter of very exact computation to determine how many ounces of proteid food, how many ounces of starchy food, and how many of fatty foods should be consumed during the day, and experiments have been made in asylums, prisons, and on companies of soldiers with a view to proving the theoretical figures.

It has always been found that an overdose of proteids results in inability to absorb the excess, and it has been assumed that a ratio of proteids to carbohydrates of one to four is approximately the proper proportion. For instance, Koenig (1888) shows the minimum daily need of food stuffs at different ages and two American authorities, Atwater and Chittenden, have also laid down standards; all three being shown in the preceding table.

The following table taken from Rough and Sedgwick's book, already referred to, gives the percentage composition of some of the more common foods:—

TABLE XVII

Water Proteid Starch Sugar Fat Salts
Bread 37 8 47 3 1 2
Wheat flour 15 11 66 4.2 2 1.7
Oatmeal 15 12.6 58 5.4 5.6 3
Rice 13 6 79 0.4 0.7 0.5
Peas 15 23 55 2 2 2
Potatoes 75 2 18 3 0.2 0.7
Milk 86 4 — 5 4 0.8
Cheese 37 33 — — 24 5
Lean beef 72 19 — — 3 1
Fat beef 51 14 — — 29 1
Mutton 72 18 — — 5 1
Veal 63 16 — — 16 1
White Fish 78 18 — — 3 1
Salmon 77 16 — — 5.5 1.5
Egg 74 14 — — 10.5 1.5
Butter 15 — — — 83 3

It will be noted that meats, cheese, and such vegetables as peas are high in proteids, while certain other vegetables, as rice and white flour, are high in starch or carbohydrates. According to the table given above, a man at moderate work requires 4.1 ounces of proteids and 17.5 ounces of carbohydrates per day. If, then, the carbohydrates were to be made up entirely from potatoes, 18 per cent of which is starch and he should need 17.5 ounces, he must have 100/18 of 17.5 or 97 ounces of potatoes per day, an amount equal to about 6 pounds. If, however, with the potatoes, he should eat half a pound of bread, of which about half is carbohydrates or 8 ounces, the amount of potato necessary would be cut down, and so on with as many combinations as one might choose to make.

It is curious, however, that when different kinds of food are available, one naturally combines different articles of food, so as to make up the well-balanced daily ration, so that the different parts may have the proper proportion. For instance, butter is always used with bread in order to add to the proteid and starch of the bread the necessary fat. With potatoes or rice, either butter or gravy or meat is always used because potatoes and rice are lacking in proteids as well as in fats which the meat supplies. Bread and cheese are well known to make up a good combination, and the table shows why: the bread furnishing the starch and the cheese the proteid and fat. Eggs alone are a very poor article of diet since no starch at all is present, and therefore it is that when eggs are eaten for breakfast, as is so generally the custom to-day, either a generous helping of cereal ought to be given with the egg or else a generous supply of bread or toast ought to be included in the breakfast. Milk is generally considered an ideal article of food, and yet it contains no starch, and it is undoubtedly because of this fact that milk and bread is more palatable as well as more nutritious than milk alone.

Human appetite.

One other factor needs to be considered in this matter of selecting one's daily food, and that is the respect which must be paid to the appetite. The most carefully balanced ration will fail to satisfy the ordinary human being unless it is served attractively and unless sufficient variety is provided. To be sure, soldiers in the army are furnished a carefully computed ration consisting of so much meat, either fresh or salt, so much bread, and so much vegetable food, and the variety being small, the soldier has to put up with his dislike to the same food day after day. The need of fresh vegetables has been proved by the results of a continuous diet of salty food on certain classes of men, such as sailors.