Under the consideration of glycosuria and diabetes, we have seen that the unoxidized sugar accumulates in the blood - and, indeed, in other juices of the body - whence it is removed by the urine and, to a less degree by other secretions. In the extreme form of diabetes, not only is there failure of oxidation of sugar derived directly from ingestion of carbohydrates, but sugar is produced in the body from fats and protein.

Except that unoxidized fat does not accumulate especially in the blood and is not removed by the secretions - owing to its physical state and insolubility in water - but accumulates as inert, practically foreign matter in the cellular tissues, and excepting that the mechanic symptoms of fat accumulation are greater than those of sugar accumulation and that the loss of energy by failure of oxidation of fats is relatively insignificant, as compared with that of sugar, obesity is analogous to glycosuria and diabetes in each of these three stages.

Corresponding to glycosuria, is obesity of mild degree, due to disproportion between supply of food and oxidation. There are, however, these practical differences: Glycosuria not amounting to true diabetes never occurs except-after the ingestion of excessive amounts of sugar of one kind or another, as discussed elsewhere while obesity may occur not only from abnormal ingestion of fats but even more so from abnormal ingestion of carbohydrates and even of proteins, since all organic foods may be changed into fat and since an excessive increase in the ingestion of fat results in catharsis and failure of primary digestion and absorption.

Corresponding to true diabetes of mild degree, whose hyper-glycaemia and glycosuria may be controlled, by limiting the diet, is a more marked degree of obesity, but which may be reduced or at least kept stationary by dietetic limitation and measures directed toward an increase of oxidizing power.

Corresponding to diabetes in which sugar continues to appear after the elimination of carbohydrates from the diet, on account of the transformation of fats and protein into sugar, is a grade of obesity in which, after the total elimination of fats from the diet and even the reduction or carbohydrates and protein far below the needs of the body, fatty deposit continues. Such an extreme grade of obesity seems to be a generalization of the well recognized local process of fatty degeneration.

In all grades of obesity, by clearing out the bowels and re-ducing the ingestion of all substances, especially water, a rapid initial decrease of weight may be secured. While such procedures may be indicated on other grounds, they are obviously fallacious so far as the reduction of obesity is concerned, since they merely remove substances not properly part of the body. The rate of decrease cannot be maintained except by inducing phases of starvation, and, in the extreme grade of obesity, the patient may even starve to death without a notable loss of fat.

In obesity of the lowest grade, the management of the case - barring other indications - is purely hygienic and dietetic, and is both simple and satisfactory except that established customs of relative overeating can not be changed without considerable mental hardship and even hunger and genuine weakness due to the failure of the body to accommodate itself to the necessity of greater assimilative oeconomy. As in the limitation of other appetites, ultimate success depends upon the courage and perseverance of the patient.

Different individuals differ greatly in the oeconomy with which they digest, absorb and assimilate the respective kinds of organic food (protein, carbohydrate and fat). Moreover, caloric needs differ according to exercise, exposure to cold, mental effort, sexual expenditure of energy, circulatory and respiratory facilities for oxidation, activity of oxidative ferments, loss of calories by radiation and perspiratory evaporation, etc. A short, compact, rounded figure affords less area for the last two sources of loss of calories and even for the oeconomic distribution and utilization of nutriment, than one of the same mass, but long and angular. In all these ways, obesity tends to establish a vicious cycle by preventing the consumption of heat units.

Bearing in mind these various factors, the treatment of obesity consists of a hygienic regimen to increase oxidation and elimination of heat units and a dietetic regimen to produce a deficit of heat units demanding compensation by the oxidation of deposited fat.

At the outset, it is obvious that an unreasonable restriction of water tends to lessen the elimination of heat units by evaporation and interferes in various ways with the physiologic processes necessary not only for the preservation of general health but even the accomplishment of the immediate end of reduction of fat. So, too, the reduction of protein below the minimum of about 60 grams a day, also acts in the last two ways.

Exercise sufficiently active to produce perspiration is of great value if not contraindicated by a weak heart or brittle arteries. Every liter of sweat indicates the consumption of 580 calories, or of 62 grams of pure fat or the reduction of weight by 75 grams. At this daily rate, the reduction of weight would amount to about 2\ kilograms or about 5 1/4 pounds a month.

Even the excessive reduction of purely calorific foods, fat and carbohydrate is contraindicated, partly because of the general reduction of bodily strength, partly because of special factors concerned in the oxidation of fat.

Every kilogram of adipose tissue contains about 800 grams of fat, whose complete oxidation would yield about 7500 calories, or sufficient to maintain the heat and energy of the body for three days, on the average. Thus the theoretic maximum of fat reduction, is only a trifle over 2 kilograms or about 5 pounds a week. But the healthy body can not oxidize sufficient fat to furnish all its daily requirement of energy, much less the obese body. Even if it could do so, there would be an inevitable partial failure of oxidation, resulting in the formation of fatty acids and producing a serious toxaemia.

The safe limit of fat oxidation a day, is somewhat less than 150 grams or about 1000 calories. Thus, we may reasonably endeavor to secure a corresponding oxidation of deposited fat to this extent, corresponding to a weekly loss of weight of about 1 kilogram (2.2 pounds). Deducting the 1000 calories from the ordinary daily requirement, the diet should therefore, yield about 1500 calories.

In establishing such a diet, it is advisable to omit butter and fat meat, to use milk instead of cream, and to omit sugar and most starchy foods. It is not necessary - and it would be impossible - absolutely to avoid the administration of fat and sugar. A ration fairly corresponding to the requirements, is as follows:

The total caloric value of the above ration is 1596.5 and the protein in grams (obtained by dividing the protein calories by 4.5) is 77.77. Various cereals, kinds of meat, fruit etc., may be used, as well as moderate amounts of weak tea and coffee, with milk instead of cream. By cutting down the meat, eggs or milk, the proteins may be reduced to the Chittenden standard and, even without this reduction in calories, considerable allowance of relishes, such as radishes (not olives), lettuce, cabbage and various other innutritious vegetables may be made. Not only are such vegetables poor in nutritives but such as they do contain are imbedded in cellulose so as to be wasted to a large degree and, by stimulating peristalsis they increase the waste of other nutriments. In general, bulky foods are to be preferred, as they satisfy the appetite with minimum quantities of nutriment. For instance a popper full of pop-corn weighs only about 20 grams, and contains only 80 calories.

The writer would condemn the use of yeast to destroy carbohydrates ingested - purposive vomiting after satisfying the appetite is just as rational and less harmful - , of vinegar, soda etc., to interfere with digestion, of cathartics to diminish the time and thoroughness of intestinal digestion, of any exclusive diet as of meat, grapes, oatmeal etc., or in short of any extreme measure interfering with assimilation.

The use of tobacco, which diminishes oxidation, should be interdicted or much restricted. Exercise, to the point of producing perspiration but not excessive fatigue, avoidance of too heavy clothing, day or night, deep breathing, stimulation of the skin and circulation by baths, alcohol rubs etc., are hygienic measures favoring oxidation.

In obesity of the second grade, there is a genuine diminution of the oxidizing power and, unfortunately, we do not know exactly where this function resides nor how it works. In addition to the methods described, it is advisable to stimulate fat oxidation directly. Thyroid extract and ovarian or testicular extract according to sex, have been suggested on theoretic grounds and sometimes work well. The administration of oxygen in adequate amount is impracticable and probably would be unavailing, as the real failure is of some oxidizing agent, probably a ferment.

It should not be forgotten that the reduction of fat is less important than the maintenance of general health, so that extreme dietetic measures should not be undertaken.

Obesity of the third degree is distinguished by the failure of all measures and the further deposit of fat. The theoretic indications are the same and it is even more important than in the lower grades, not to weaken the patient by ineffectual starvation, since the impoverishment of nutrition actually increases the tendency to fatty degeneration.