During the last few years, there has been growing medical interest in the problem of obesity. Although this may not have resulted in a dramatic breakthrough in our understanding of the condition, at least we are now more aware of our ignorance. Possibly this partly explains the increasing medical concern for, and sympathy in, the management of the obese. In the introductory chapter, John Garrow says that he believes it would be better to treat a few people well than many subjects unsuccessfully. This theme is developed in those chapters which deal with specific forms of therapy including exercise, protein-sparing fasting and bypass surgery, while the chapters on pharmacological agents review our knowledge, and our ignorance, of the mode of action and efficacy of the currently available drugs. Almost in contrast, the chapter on behavioural therapy and group therapy suggests that obesity is a problem which could best be tackled on a community basis. Clearly such an approach is very attractive, and the combination of behavioural therapy and slimming organizations would appear to offer the best prospects of controlling most subjects' weight problems.There will always remain, however, the individual patient in whom there will be a place for the various special techniques now available. It is hoped that this book will contribute to a greater understanding of the various problems faced by the obese, and the regimes that can be offered. J. F. MUNRO xi 1 How to treat and when to treat J. S.