Who would not rejoice to find a magic bullet that we could fire into obese people to make them permanently slim and healthy? In the United States about a third of adults are obese—that is, have a body mass index (weight(kg)/height(m)²)) above 27.1 The diagnosis can be made with reasonable accuracy by anyone. Obese people appear “chunky” and usually have some abdominal protuberance with or without unsightly thighs. Tens of billions of dollars are spent on diets, pills, spas, or special foods and advice on behavioural change. Any scientific discovery that deals with food intake or obesity quickly becomes a “hot item” for the media. The best seller list usually contains a book giving recommendations for a new diet or mixture of diet and behaviour that assures successful weight control. Medical authorities, particularly public health officials, warn the public of the rising prevalence and hazards of obesity.

A recent editorial in the New England Journal of Medicinedocumented the failures of current treatment and questioned the benefits of weight loss while reminding us of the strong correlation of obesity with disorders such as hypertension and diabetes.2 Since current treatment so often fails, only a magic bullet would allow us to perform an experiment to determine the full benefit of weight loss. Are we on the brink of finding a drug which will solve the problem?