As the obesity epidemic spreads, concern about the significant health and economic consequences has also grown. Obesity has been linked to a variety of chronic diseases, almost 300,000 deaths each year, and 117 billion dollars in direct and indirect annual costs in the United States alone. In this article we review the recent trends in overweight and obesity, summarize the lifestyle factors that influence the increasing prevalence of obesity, and discuss the health and economic impact of the obesity epidemic.