Obesity in the adult is defined as a body mass index ([BMI], weight in kilograms (kg) divided by their height in meters (m) squared) greater or equal to 30 kg/m(2). In children, obesity is defined by using BMI values beyond percentiles from a reference population. Most countries are undergoing or have undergone, demographic, epidemiological, and socioeconomic transitions that are accompanied by a nutritional transition. Obesity is linked to major modifications of the environment (urbanization and mechanization) of rapid onset, with dietary modifications and a decrease in physical activity. Obesity is rapidly increasing in developing countries. The epidemic of obesity has become pandemic, occurring over a wide geographic area and affecting over 400 million adults worldwide. Similar to adults, the prevalence of obesity increases in children.