Obesity

During the final two decades of the 20th century, a dramatic increase in the prevalence of obesity occurred in the United States and in many developed and developing countries throughout the world. By the end of the 20th century, there were more than 1 billion overweight adults worldwide, among whom more than 300 million were obese. Obesity had become a significant contributor to the global burden of chronic disease and disability and a major public health issue. The rising rates among children were a particular concern. This entry considers the definition and epidemiology of obesity, its health consequences, the causes of obesity, and efforts to address it through public policy.