COMMITTEE ON NUTRITION

Abstract

Despite an imposing body of information derived from research, our ignorance concerning the etiology, pathogenesis, and treatment of obesity is remarkable. It is clear that when considering a given patient the terms "overweight" and "obese" are not necessarily synonymous. Evidence derived from various viewpoints suggests that obesity cannot be regarded as an etiologically unique metabolic disorder. It is likely that an excess of adipose tissue in man will ultimately prove to represent a clinical end-point common to a variety of hereditary and acquired disorders, as in the case of experimental animals, rather than a singular morbid condition with unique pathogenesis. The identification and evaluation of the inherited, acquired, metabolic, and psychogenic determinants of obesity still present an urgent challenge for future research. Mortality and morbidity rates for diabetes and cardiovascular disease are higher in obese adults than in those of average weight. These risks appear to be diminished by weight reduction. Because the majority of obese children do tend to remain obese as adults and because our society exerts considerable pressure towards relative leanness as a criterion for social acceptability, early treatment of obesity would seem to be a worthy objective. However, the fact is that no methods of treatment have as yet achieved more than minor success in significant sustained weight reduction. Since the natural history of childhood obesity remains ill-defined, the results of testimonials from inadequately controlled studies with short follow-up periods (less than 2 or 3 years) must be viewed with skepticism. Any attempts to achieve lasting weight reduction in obese children and adolescents should be tempered by a realization of the inherent difficulties of treatment and by sympathy for those children who, for reasons poorly understood by their physicians. lack the ability to regulate the delicate balance between physical activity and caloric intake. It appears that when treatment is directed at only a single element of the thermodynamic equilibrium, caloric intake, the chances of successful and lasting weight reduction are small. Prophylaxis may offer the most logical method for dealing with obesity. Prevention is necessary in high-risk families and should be undertaken by the family physician. The role of public health programs implemented by education may decrease the level of obesity in the remainder of the population. The efficacy of either approach remains to be determined. While there is knowledge of some of the metabolic derangements characteristic of the obese adult, little is known about these in childhood. In view of the apparent hazards of obesity in adult life, the patent failures characteristic of virtually all therapeutic approaches and the scientific void in knowledge of pathogenesis or pathophysiology make the study of obesity a compelling undertaking for the investigator.