Randomized controlled trials (for example, the Diabetes Prevention Program) have demonstrated that metformin can help in the prevention of type 2 diabetes. But lifestyle intervention (diet, exercise and weight loss) was more effective (60% risk reduction vs 30% with metformin), in diabetes prevention over 2.8 years. Recently published follow-up data from diabetes prevention trials have shown that the effect of lifestyle modification is sustained. Lifestyle should therefore still be the first choice in management. For patients who are unable to participate in a lifestyle intervention, however, metformin is a valid therapeutic option.