Most people have some dissatisfaction or concern about body weight, fatness, or obesity, either personally or professionally. This book shows how the popular understanding of obesity is often at odds with scientific understandings, and how misunderstandings about people with obesity can further contribute to the problem. It describes, in an approachable way, interconnected debates about obesity in public policy, medicine and public health, and how media and social media engage people in everyday life in those debates. In chapters considering body fat and fatness, genetics, metabolism, food and eating, inequality, blame and stigma, and physical activity, this book brings separate domains of obesity research into the field of complexity. By doing so, it aids navigation through the minefield of misunderstandings about body weight, fatness, and obesity that exist today, after decades of mostly failed policies and interventions.