Not long ago, a patient, whom I will call Mrs Bariatrico, asked me to prescribe a diet pill for her. Mrs Bariatrico is a middle class woman aged 48 years. She is 1.6 m tall and weighs 77.2 kg. Her body mass index is 30.2 and her waist to hip ratio is 1.0. Mrs Bariatrico is healthy and does not smoke. She told me she plans to enrol in a commercial diet programme and believes her ability to change her lifestyle is good.1 Her main concern is cosmetic—she values “looking good” and considers weight loss an important outcome.

As her primary care provider, I had several concerns. I knew the health insurance system that serves Mrs Bariatrico has no formal weight loss programmes, and the cost of appetite suppressing drugs is not reimbursed. I had some doubts about my own ability to manage obesity and asked the following questions:

• What are the actual health risks associated with obesity in a middle aged woman with few cardiovascular risk factors?

• What are the expected benefits and hazards of weight loss?

• What are Mrs Bariatrico's treatment options and their expected benefits and adverse effects?