ABSTRACT
INTRODUCTION Bariatric surgical procedures have traditionally been divided into two categories, malabsorptive and restrictive, based upon the mechanism by which they were thought to induce weight loss. More recent research has proposed that changes in postoperative satiety hormone level and basal metabolic rate are responsible for the majority of weight loss in bariatric procedures. Hormones such as peptide YY (PYY), glucagon-like peptide 1, oxyntomodulin, and ghrelin are thought to regulate appetite, sensations of fullness, and metabolism. The most commonly performed bariatric procedure, the gastric bypass, has been studied in this regard. This operation is characterized by immediate and prolonged loss of appetite resulting in weight loss due to decreased calorie intake rather than by restriction or malabsorption (1) .
