There are currently two drugs approved for use as part of the medical treatment of obesity. They have been developed in recognition of the fact that it is a complex disorder, where, for example, genetic effects on appetite are very difficult to manage, especially in our weight-promoting environment. But they aren’t a magic weight loss bullet. They must still be used as part of overall lifestyle change – they just make that change more manageable for some.

The two drugs come with strict criteria about who they can be prescribed for, and for how long. Orlistat (Xenical) works by reducing the amount of fat that you absorb by about one-third, and must be taken with a low fat diet (other wise unpleasant bowel problems can result). Sibutramine (Reductil) helps you feel more satisfied with less food by regulating the action of appetite-influencing chemical messengers in the brain. Like other responsible treatments, they help people lose modest, but beneficial amounts of weight.

These two drugs have a recognised role to play in obesity treatment, and are very different from other drugs that might be available from private ‘diet clinics’ or over the Internet. These include appetite suppressants and diuretics (force the body to lose fluid). We definitely don’t recommended them.