The need to treat obesity successfully can be measured by the medical penalty paid by the obese individual and the financial price paid by society in general. The management of obesity has 2 objectives: first, to produce significant weight reduction (10% of pretreatment bodyweight) and, second, to maintain this weight reduction. For the purpose of this paper, we have defined successful treatment as that maintaining significant weight loss for at least 5 years. A review of the literature confirms that there is no single outstanding treatment for obesity, and that clinicians must consider an individual's needs before selecting a particular method of weight reduction. The main determinants of suitability of any specific treatment are degree of obesity, concomitant medical disorders, urgency of treatment, and the individual's willingness to undergo the programme prescribed.