The physician is frequently confronted with the problem of modifying the bodily weight in one or the other direction. Many chronic maladies are accompanied by considerable loss of weight, and in their enfeebled state the patients are greatly hampered in their battle against disease. If, however, we succeed in putting them into a better general condition, then they are enabled vigorously to combat their troubles. To obtain an increase in weight is therefore here of primary importance.

An excessive bodily weight also leads to disagreeable conditions, occasionally even to disease. Accumulations of fat around the heart and intestines impede the action of these organs. The ponderous body is sometimes too heavy for the legs; laziness results, leading occasionally to fatty degeneration of important muscles, including the heart. In all these cases a reduction of bodily weight must be sought.

. It does not appear superfluous, therefore, to discuss the question how to change the bodily weight in one or the other direction.

I. The principles governing these problems are intimately connected with the physiology of metabolism and must first be briefly considered.

1 Read at the annual meeting of the Monroe County Medical Society, at Rochester, N. Y., May 27th, 1903. Medical Record, July 18th, 1903.

The Revenues And Expenditures Of The Body

In the life of every being there is a constant exchange of revenues. and expenditures. The revenues of the body consist, as we all know, of food and air; the expenditures, of the generation of bodily heat necessary for life and of the work performed (heart action, respiration, glandular activity, muscular work in general).

The value of food is measured by its caloric energy. Heat may be transformed into power and the latter into the former. The mechanical equivalent of one calorie = 425.5 kgm. If the work performed (expressed in kilogrammeters) is known it can be calculated according to the above formula in calories, i.e., we can tell exactly how much heat is consumed in the work accomplished. The human organism, however, is not able to convert the entire number of heat units into work. According to Von Noorden,1 the organism requires for a certain amount of work about four times the amount of potential energy; in other words, seventy-five per cent of the calories, changed into power, are given off in the form of heat which radiates from the body and is thus lost.

A person performing about 4,000 kgm. work uses, therefore, (4.000 / 425.5) * 4 = 37.6 calories.

The amount of food for the adult per day has been calculated at about 2,600 calories.

Body Equilibrium

If the amount of food taken is just sufficient for all demands of the body we have a balancing of bodily weight or bodily equilibrium, i.e., the organism neither loses nor gains in weight.

What Happens When More or Less Food is Taken! -Formerly the view prevailed that the more food is supplied to the animal organism the more material it burns up. As a proof of this theory, the fact was adduced that a short time after eating the consumption of oxygen and the elimination of carbonic acid gas were found to be increased. Speck 1 proved, however, that the increased consumption of oxygen was to be ascribed to the increased activity of the digestive glands, and therefore the theory of augmented combustion of increased nutritive material had to be abandoned. There are numerous proofs that the organism does not burn up food introduced in excess, but rather utilizes it and converts it into fat.

1 C. v. Noorden: "Lehrbuch der Pathologic des Stoffwechsels," Berlin, 1893.

On the other hand, the organism consumes just as much material even when no food is taken, using up its own substance (fat and muscles). In acute inanition the adult usually expends about 2,100 calories; in protracted inanition somewhat less, about 1,700 to 1,900 calories per day. The loss of nitrogen of a healthy fasting man is about 10 to 11 gm. daily.