From all that has been said it is clear that obesity may be due to a great variety of causes. Before any plan of treatment is formulated the habits of life of the patient must be carefully and exactly determined in order that the cause of the obesity may be elicited in each particular case. This knowledge renders the treatment much more easy and gives greater assurance of ultimate success. A form of obesity, for instance, occurring in an otherwise healthy individual, quite apparently on account of too little physical exercise combined with too much eating, i.e., the ingestion of an amount of food that exceeds average values, should be combated primarily by greater activity and stimulation of all the factors that lead to a consumption of energy; in other words, by an increase of muscular activity. Provided one would limit one's self in a case of this kind to reducing the food intake, one would, of course, obtain some loss in weight, but would at the same time most assuredly do damage to the muscular powers of the individual. On the other hand, there is a class of obese subjects who perform an abundant amount of very strenuous bodily labor, but, nevertheless, grow fat and remain so, because they satisfy the increased demand for food, that is stimulated by this labor, without restraint. In such individuals there is nothing gained by insisting upon a still further increase of muscular activity, for this very measure would only lead to a still greater stimulation of the appetite. Such individuals should be taught to be moderate in eating; in other words, they should be instructed how to satisfy their appetite with articles of food that are filling but possess only a small caloric value.