In this issue of Gastroenterology Clinics, guest editor Dr. Lee M. Kaplan brings his considerable expertise to the topic of Management of Obesity, Part I:  Overview and Basic Mechanisms. Most of the world's population live in countries where being overweight and obese is more life-threatening than being underweight. This preventable disease leaves patients with a cascade of health problems, resulting in serious stress and impact on global economies and healthcare systems. This issue, the first of two, addresses basic mechanisms and contributors of obesity, along with health care disparities and access..