Page:Popular Science Monthly Volume 83.djvu/350

346 article of food, as purchased or as served on the table, which yields 100 calories of energy. This he has called the "standard portion."

Often it happens that the quantity required to make a standard portion is a very convenient amount to serve on a plate. One large egg, weighing 2 ounces, is almost exactly a standard portion. An ordinary serving of butter ( ounce), a teaspoonful of olive oil, one large orange, one large banana, one medium thick slice of white bread—each contains very nearly 100 calories of energy. By an easy computation one can readily learn the exact weight of any kind of food whose composition is known, which will yield 100 calories. It would help greatly if some enterprising manufacturer were to place on the market standardized measures made in metal for a standard portion of sugar, milk, rice, butter, oatmeal, flour, dried beans and any other food which does not vary much in composition. The only difficulty with this method is that certain food products as purchased in the market differ considerably in composition. It would therefore be much simpler for the consumer if the food manufacturer were required to guarantee not only the purity of his product in the ordinary sense, but to guarantee also a certain energy content. If, for example, a certain brand of oatmeal bore on its label the statement, "This package is guaranteed to contain 2,000 calories of heat energy," this information would be worth many times as much to the purchaser as the statement, "This food is guaranteed to comply with the food and drugs act," etc. For he would then have some basis upon which to judge the actual economy of his purchase. Some other product likewise "guaranteed to contain 2,000 calories" might cost him only one half as much.

Such a guaranty would entail no great hardship on the part of the manufacturer, because it would involve the employment only of a competent chemist to make an occasional analysis, or a determination by combustion of the heat value. The law of many states already requires that milk admitted to the markets must not fall below a certain percentage of fat (cream). If the label on top of the bottle were required to state, "This bottle contains 650 calories of food energy," the legal requirement would mean something to the purchaser, for it would enable him to tell whether milk is or is not a cheap food as compared with, say, oatmeal or eggs.

A person must have a certain minimum of energy value in his food every day. There is no law of nature more inexorable than this. Certain faddists like Horace Fletcher have averred that they live on much less energy than does the average man, and yet when Mr. Fletcher was