Excess weight is major medical problem for more than one third of Americans and after cigarette smoking, is the second largest cause of death. However, obesity treatments remain controversial, and only surgical therapies have patient volume and appropriate follow-up adequate to prove effectiveness. Today’s challenge in health care is to prevent or diagnose, treat, and manage acute or chronic diseases that affect many people while controlling cost, maintaining standards of care, and improving quality of life. Obesity is one such treatable disease because of its association with physical, psychosocial, and disability costs that affect quality of life. For the severely obese, it is a chronic, heterogeneous, multisystemic disese that has many equivocal causes and consequences. Recent findings show the importance of genetic factors as a major influence in the etiology and refractory nature of obesity. Aggressive, medically supervised interventions, such as very-low-calorie diets (VLCDs) and pharmacologic and surgical treatments, are especially needed for genetically susceptible individuals who do not respond to low-risk dieting and behavioral modification treatments or cannot maintain a healthy body weight despite multiple attempts to lose weight. A model is neede to incorporate these obesity treatment guidelines into an everyday clinical physician practice....