Obesity is a common problem in Type 2 diabetes mellitus, and reduction of weight in obese diabetic patients will lead to an improvement in glucose tolerance. Despite the importance of weight loss, obese diabetic patients often fail to lose weight with advice on dietary restriction. Frequent visits to see the dietician provide the best chance of successful weight loss, and should be an important part of the management of the overweight patient. If this line of treatment is unsuccessful, then drug therapy may be considered to assist the patient in adhering to the dietary restriction. Over the past decade, drug therapy for weight loss has fallen into disrepute in the wake of the abuse of amphetamines and thyroid hormones by both patients and doctors. For this reason, the only drug commonly used in the diabetic clinic to assist patients to lose weight is metformin because of its putative therapeutic effect on obesity. However, currently available anorectic agents have much less potential for abuse by patients than their predecessors, and new drugs are being developed in this field.