In the last three decades, the prevalence of obesity has doubled with over 600 million obese adults worldwide. The gastrointestinal complications of obesity are well publicized; however, the role of the gastrointestinal tract in the development and treatment of obesity is often understated. From the pathophysiologic role of gut hormones and the microbiota, to the purposeful, anatomic derangement of the gastrointestinal tract that is utilized as a treatment for obesity, it is imperative that gastroenterologists understand the full scope of obesity in relation to the gastrointestinal system. Studies suggest that in the U.S. obesity is underrecognized and undertreated by health care providers. Given its complex sociology, pathophysiology, and treatment, obesity, like many other diseases, requires a multidisciplinary approach. Therefore, gastroenterologists must be equipped with the relevant knowledge of obesity that will empower them to properly manage their patients.