Body mass index of 30 kg/m2 or higher is used to identify individuals with obesity. In the last 3 decades, the worldwide prevalence of obesity has increased 27.5% for adults and 47.1% for children. Obesity is the result of complex relationships between genetic, socioeconomic, and cultural influences. Consumption patterns, urban development, and lifestyle habits influence the prevalence of obesity. The condition may be the result of disease or pharmacologic treatment. It may also be a risk factor for the development of comorbid conditions. Persons who are obese have less school attendance, reduced earning potential, and higher healthcare costs that may result in an economic burden on society. A review of the prevalence and economic consequences of obesity is provided. Potential causes and comorbidities associated with obesity are also discussed.