Nitrogen Balance - Energy Value Of Food.

We are now in position to understand something of food values, which depend on the food actually utilized in the body, to the exclusion of food unabsorbed, or eliminated because in excess of the demands of the system. Energy-yielding material which is not used at the time may be stored, but beyond a certain point, stored nutriment must be regarded as undesirable, as in obese subjects.

As stated by Atwater, the food supplies body wants in five ways: (1) tissue-building, (2) tissue-repairing, (3) storage for future use, (4) oxidation to maintain animal heat and (5) oxidation to supply energy; or we may say that according to function, foods are classified as tissue-formers, or body-builders; energy (or work and heat) producers; and regulators of body processes. (See page 5. )