190. Fate Of Excess Food

Again, if a person consumes carbohydrates and fat in excess of the maintenance needs of the body, what is their fate? The scientific evidence is that there is no increase in energy exchange; that is, in the final transference of the potential energy of the food into heat, which is the measure of such exchange, but that the surplus is stored in the body. It is hardly conceivable, anyway, that the energy of excess food would be exactly disposed of in the work of getting rid of the excess.

If this were the case, then the necessary energy expenditure would be directly proportional to the amount of food digested, unless storage in the body occurs, - an absurd proportion.

191. Experimental Evidence

Those who argue for a restriction of the diet below the ordinary eating practices point to certain experimental observations as furnishing proof of the correctness of their position. Reference is not here made to the claims of food "faddists" who, without any adequate knowledge of scientific fundamentals and without accurate observations, proclaim the blessings of a minimum diet. Their unsustained assertions may be passed by without discussion, for so far as they have been investigated they have proved unreliable.

When, however, such a distinguished scientist as Dr. Chittenden of Yale University advocates greater moderation in eating and presents a mass of carefully observed data to sustain his views, the matter becomes worthy of careful consideration. The work of Chittenden1 was undertaken primarily to investigate the minimal necessary supply of protein, but the data permit observations on the energy supply. It seems that he succeeded in maintaining a uniform body weight on what he estimated to be a food energy of approximately 1600 calories daily. Under the change in diet his weight fell from 144 pounds to about 126.5 pounds, after what it remained practically constant. Observations were made by Dr. Chittenden on four other subjects who maintained a fairly uniform body weight on food estimated to furnish daily from 2000 to 2500 calories. These figures seem low when it is recalled that calorimeter measurements of energy exchange by several subjects of varying weight (43 to 82 kg.), in absolute muscular rest and in a hunger condition, showed a daily heat production of 1214 to 1656 calories, while the exchange of somewhat heavier persons when asleep has been found to vary between 1418 and 1853 calories.1 (See Table XXVII.)

1 " Physiological Economy in Nutrition," pp. 19-51.

Chittenden's five subjects, though active, were engaged in mental rather than physical labor, and were of light weight, from 126 to 143 pounds (57.3 to 65 kg.) It has been shown that mental labor does not require an amount of food energy that is appreciable through calorimetric measurements. Further experiments were conducted by Chittenden2 with seven college athletes which continued during five months. In these experiments the protein food taken was deliberately made much below the quantity usually consumed at the training table, and the total quantity of food eaten was also diminished. Seven-day balance trials having for their object a determination of the intake and outgo of nitrogen show that seven of these, weighing from 123 to 171 pounds apiece, are estimated to have presumably received food varying in energy from 2174 to 3091 calories. These figures are much below the standards obtained from a study of the actual dietaries of equally active persons in ordinary life.