Obesity affects both physical health and psychological well-being and is one of the biggest obstacles to the management of type 2 diabetes. Commercial weight loss programmes have been shown to be better than standard management, and in some areas in the UK general practitioners are now enlisting commercial slimming organisations to help patients lose weight. One such approach is called ‘Slimming on Referral’, which has reported some short-term success to date without the robust methodology of a longitudinal randomised controlled trial to support these findings. Results from this study are in line with a substantial body of previous research which indicates that interventions for obesity demonstrate moderate success in promoting short-term weight loss. There is, however, almost no evidence that the vast majority of people can maintain clinically significant weight loss over the long term and virtually everyone returns to their baseline weight. Furthermore, research suggests that weight fluctuation may have profound effects on psychological and physical health. The present paper highlights the need to reappraise the management of obesity in type 2 diabetes in the light of these research findings, and suggests an approach to treatment which would help patients to limit the associated physical and psychological costs and importantly ensure that the treatment itself does not compound their difficulties. Copyright © 2006 John Wiley & Sons, Ltd.