Obesity: identification, assessment and management

Is there a medicine that can help you lose weight?

There is a medicine – called orlistat – that people can take to help them lose weight. It works by stopping your body from absorbing as much fat from your food. It is not suitable for everyone, you may need to take supplements to make sure you get all the vitamins and minerals you need, and it can have side effects. Your healthcare professional may suggest trying it if you have been following advice on eating less and being more active for some time, but have still not lost enough weight. You may also be offered the medicine to help you maintain or lose weight if you are going to have surgery for obesity but cannot have an operation straight away.

The medicine is normally recommended only for people with a BMI over 30. But if you might be at risk of problems related to being overweight or obese – for example if you have diabetes or high cholesterol – your doctor may suggest trying orlistat if your BMI is 28 or above. If you have type 2 diabetes it may take longer to lose weight, so with the help of your healthcare professional you should set realistic goals that are easier to reach.

You should have an opportunity to ask any questions you want about the possible benefits and side effects before you decide whether to go ahead with taking the medicine. If you do decide to take it, you should have regular appointments with your doctor. You will also still need advice and support to help you continue with the changes to your lifestyle. If you don't manage to lose weight while taking the medicine, your doctor may advise you to stop taking it.

Once you have lost weight, your doctor should talk to you about whether to carry on taking the medicine to help you keep the weight off.

For children, only a specialist should prescribe medicine to help them lose weight, and even then this should only happen if their specialist considers that their weight is putting their health at serious risk. Children who are taking medicine to help them lose weight are looked after by a specialist team who give extra help with lifestyle changes and check how the child is getting on with the medicine.