Obesity: Physiologic Considerations

Abstract

The problem of appetite control will not be attacked rationally until more is known about the mechanism of regulation of food intake. While a general scheme is now available relating gastric contractions to hypothalamic centers and suggesting ways whereby the metabolic state of the organism influence hypothalamic function, much work remains to be carried out on these aspects as well as on the interrelationship of higher centers. Obesity, like anorexia, can be the result of a great many disturbances in the mechanisms regulating food intake. From the standpoint of etiology one can speak of genetic, traumatic and environmental factors. Genetic factors are of particular interest. A large proportion of children of obese parents are obese, with environment appearing to be responsible only in part. This suggests that preventive programs aimed at children of overweight parents should be started early. Among environmental factors, exercise has been very much underestimated in weight control, both in terms of etiology and therapeutics. From the point of view of pathogenesis, one can distinguish between regulatory obesity, in which the error lies in the mechanism regulating food intake (e.g., hypothalamic obesity and psychogenic obesity); and metabolic obesity, in which the error lies in carbohydrate and fat metabolism (e.g., obese hyperglycemic syndromes and obesity due to excessive ACTH secretion).