Obesity has become a pandemic, affecting adults and children around the world. Considerable medical, scientific and lifestyle-related knowledge and resources are being channelled into the identification of strategies to combat this major public health problem. Despite these multidisciplinary efforts, however, little attention has been paid to the damaging social and psychological consequences of obesity. Many people with overweight and/or obesity frequently face stigmatization, prejudice and discrimination because of their body size and shape, with disturbing and potentially harmful implications for their emotional and physical health and well-being. Given the high rates of type 2 diabetes among people with obesity, many of those with diabetes are vulnerable to weight stigma and its consequences. Rebecca Puhl reports.