Definitions and demographics of obesity: diagnosis and risk factors

The incidence of obesity is increasing yearly among adults and children in the United States and worldwide. Although there is a significant genetic component to obesity, the genome has not changed. The epidemic is caused by an increase in dietary fat and caloric input and a decrease in physical activity. There are significant racial, ethnic, and sociologic differences in all categories of obesity as well as in the disease burden it brings. The effects of the obesity epidemic are considerable, second only to tobacco use in the expenditure of health care dollars and as a cause of premature mortality.