New concepts of physiology in obese patients.

According to recent statistical observations, obesity is one of the most common and steadily increasing diseases in the United States, with more than 7.5% of the population suffering from its morbid form. Many different studies have been undertaken with a focus on behavioral, genetic, and epidemiological aspects of this serious health concern, but its etiology and characteristics have not yet been fully defined. The obese patient represents multiple problems for the clinical physician. The biggest is the fact that the bariatric patient does not follow the common physiology learned during medical school, and therefore some morbidities and mortalities have been underevaluated and not treated adequately or promptly. To fully understand all the causes relating to the higher incidence of morbidity and mortality in obese patients, further delineation of the underlying pathophysiology is necessary. In the present article, several new physiologic concepts, based on clinical observation and specific to this population, are presented. Further clinical and experimental studies are necessary to further elucidate the etiology and to define all possible contributing factors for a full understanding of this fastest-growing disease of the new century.