Obesity and its many serious comorbidities exert a heavy toll in both human and economic terms. More than one-third of adults in the United States are obese and, therefore, subject to elevated rates of diabetes, hypertension, dyslipidemia, and other cardiovascular disease risk factors. The negative effect on the quality of life (QoL) of these individuals is enormous. Among the severely obese, QoL scores are comparable to QoL scores associated with diabetes and laryngeal cancer. The medical costs of obesity-related illnesses in the United States have been estimated at $209.7 billion annually (in 2008 dollars). For example, with regard to impact on pharmaceutical costs, obesity is associated with a more than 13-fold increase in the cost of antidiabetic medications. The cost of absenteeism to employers has been estimated to exceed $4.3 billion annually. Successful and cost-effective short-term treatments for obesity are available, and have been shown to reduce cardiovascular risk factors. Intensive lifestyle intervention with the goal of losing 7% of baseline body weight, for example, resulted in a 58% reduction in the risk of diabetes in patients with prediabetes. In clinical trials, improvements in other cardiovascular risk factors, such as elevated triglycerides and high blood pressure, have also been seen with a modest weight loss of 5% to 10% of baseline body weight. As obesity becomes an ever greater public health problem, additional interventions with long-term efficacy are needed to reduce body weight and maintain weight loss.