How To Estimate Food Values

The palate values food according to its taste. I will explain how food is valued scientifically. Since food is to the body as fuel to the engine, it may be measured in corresponding units. In coal or wood, the heat of the sun’s rays is stored. As the plant grows, it takes up heat, carbon dioxide, hydrogen, nitrogen, etc. As coal is burned, it gives off its heat, which may be transformed into energy, moving trains, weaving cloth, etc. In like manner, the work of the body is performed by the energy developed from its food products which are consumed within. It is correct, therefore, to measure food in terms of heat. It is also convenient, and serves our purposes quite well.

The calorie, our unit of food values, is the amount of heat required to raise one kilogram of water one degree centigrade. Hot coffee in a thermos bottle retains its heat because there is no radiation from the bottle. The caloric value of foods is ascertained by burning them in a calorimeter. This is an apparatus with three walls and two air spaces, radiating no heat. It is filled with water. A small metal case containing the food is immersed in this water, ignited by electrical connections, and burned. By a delicate thermometer in the water, registering 0ne-thousandth of a degree, the heat thrown off from the burning food is ascertained. The United States Agricultural Department has made over four thousand analyses, determining thereby the caloric value of nearly every article of food imaginable.

Experiments have been performed on men in a calorimeter the size of a small room, the results of which prove that the same amount of heat is developed from a given article of food in the body as when it is burned outside the body.

A certain amount of fuel is required for heating a house. This varies with the size of the house, its walls, exposure, and the weather. Sixteen hundred calories of food are required daily by a man lying quietly in bed for keeping his body warm and the heart and organs in action. Eight hundred more will enable the man to do office work, such as is done by a physician or lawyer. A certain amount of fuel will enable a given engine to haul a given load twenty miles. A man walking 2.7 miles in an hour requires 160 calories for the purpose. Sitting at a desk is quite different from many of the occupations of life. The other extreme is represented by a six-day bicycle racer. Such a man requires 10,000 calories per day.

When the central nervous system sends a command to the muscles for raising the body and moving it across the room, the entire set of actions is carried out by the burning or oxidation of one’s body fuel. Oxygen for this purpose is supplied by the inspired air and taken to the necessary muscles in the blood current.

Proteins, such as white of egg, meat, and a certain percentage of nearly all foods, are used to repair worn-out muscles and framework, and if there is more than needed for this purpose they may also be used as fuel. Fats, such as butter, oil, cream, and fat of meat, are simply fuel. Carbohydrates, as sugar and starch, are also used for fuel. The fats go twice as far by weight as the carbohydrates.

The explanation I have given answers the question ” Why do we eat? ” To answer in one sentence, I would say: “We eat to supply the body with the elements necessary to replace such tissues as are torn down from day to day, to upbuild during periods of growth, to give the energy necessary in life’s activities, and to store a reserve for emergencies.”