Obesity is a common problem in the United States, and all over the world. It is estimated that more than one-third of adults (72 million people) and 17 percent of children in the United States are obese. The most common causes of obesity include a lack of physical activity and eating an unhealthy diet. Obesity-related conditions include heart disease, stroke, type 2 diabetes and certain types of cancer. These are some of the leading causes of preventable death.