Obesity is increasingly common throughout the world. It has reached epidemic proportions in the United States and developed countries, and is even increasing in developing nations. In Asian countries, where the problem used to be atypical, obesity is becoming more prevalent. In the United States, 27% of adults are obese and an additional 34% are overweight. Over the past 30 years, childhood and juvenile obesity in the United States and the United Kingdom has grown from an individual health problem to a national crisis.