To a unit of food-energy which is equal to one hundred calories (see last paragraph on "Energy"), I have given the name of Vieno, derived from "vital" and "energy," and pronounced vi-eń-o. The Vieno system, therefore, will measure all foods by vi-en-os, or units of energy equal to one hundred of the chemist's calories. One vieno of milk is one-sixth of a quart, or two-thirds of an ordinary glass. From this it is readily seen that two quarts of milk will give twelve vienos of energy, or, if we wish to express it in the chemist's term, twelve hundred calories.
How to compute amount of nitrogen in food
The table also states that milk has a nitrogen factor of .8. Therefore, if we wish to know the amount of nitrogen in the two quarts of milk, all we need do is to multiply the number of vienos by the nitrogen factor; 12 x .8 = 9.6, which figure represents the nitrogen consumption expressed in grams. (See explanation of fourth column of table.) These results are practically the same as those obtained by the old system of computation, but expressed in simpler terms. Thus we see that the vieno system of computing food values is unique in its simplicity, and will be a very material aid in putting Food Science on a practical basis.
NECESSITY FOR A SIMPLE SYSTEM
Neither volume nor weight are correct standards for measuring food values
Things are commonly measured by volume, or by weight. That volume could not be made sufficiently accurate in the measurement of food values is evident. A bushel of lettuce leaves would contain much less food value than a bushel of wheat. Weight would seem to be a fairer way to compare foods, but all foods contain water, which may vary from five to ninety-five per cent. A pound of turnips, which is nine-tenths water, would not be comparable with sugar, which has scarcely any water.
Even if it were not for the water, weight would not be a fair method of comparison because some foods are of more value per pound than others, owing to their difference in chemical composition. For instance, a pound of butter gives about two and one-fourth times as much heat to the body as sugar.
As before mentioned, the two chief food factors which we ought to measure are energy-producing and tissue-building power.
What constitutes a true food
All true foods when assimilated in the body produce some energy. In fact, only such substances as produce bodily energy, when combined with the oxygen taken in through the lungs, can be correctly termed food.