The recommendation to treat overweight and obesity is based not only on evidence that relates obesity to increased mortality but also on evidence that weight loss reduces risk factors for disease. Thus, weight loss may not only help control diseases worsened by obesity, it may also help decrease the likelihood of developing these diseases. The NIH panel reviewed relevant treatment strategies designed for weight loss that can also be used to foster long-term weight control and prevention of weight gain. The consequent recommendations emphasize the potential effectiveness of weight control using multiple interventions and strategies, including dietary therapy, physical activity, behavior therapy, pharmacotherapy, and surgery, as well as combinations of these strategies. While the predominant audience is public health, the style of Overweight and Obesity lends itself as a practical text for primary care and endocrinology.