VALUE OF FOOD TO THE BODY
“Food is that which when taken into the body tends either to build tissue or to yield energy.”
The chief offices of food are to build the material of the body, to repair the waste which is continually going on and to yield heat to keep the body warm.
Foods may be divided into tissue-building foods and fuel foods.
The tissue-building foods are such foods as milk, eggs, cheese, wheat, meat and the legumes. The fuel foods are sugars and starches and fats and oils.
In order to keep the body in a good condition a combination of the tissue-building foods and the fuel foods is necessary, with a supply of water to dissolve them. About 125 grams of tissue-building foods and 550 grams of the fuel foods is the amount required daily. A mixed diet, therefore, is the ideal diet for the healthy adult.
The changing of the tissues and the assimilation of food are very rapid in childhood and youth, so that the system demands at that time an abundant supply of such foods as meat, milk and eggs. When middle age is reached, the amount of such food should be decreased. Otherwise the tax on the organs which take care of the wastes will be so great that disease will follow.
Thus it is clear that people of different ages require different combinations and amounts of food. The kinds of food required to nourish the healthy body vary also with the sex, occupation and climate, as well as with the age and peculiarities of the individual. In order to judge of the relative value of food to the body it is necessary to find out what percentage of each nutritive constituent the food contains, how much energy it is capable of yielding, how much of the food eaten is digested, how much is absorbed, and whether the nutritive constituents are obtained at a reasonable cost.
Farmers’ Bulletin No. 23, published by the United States Department of Agriculture, will be found interesting to those caring to study foods from the above standpoints.
Mr. W. O. Atwater, Ph. D., writes in Farmers Bulletin No. 142, on “Food and Food Economy,” the following table:—