Doctors measure obesity by 'body mass index' (or BMI).

To work out your body mass index, follow these steps:

1 Find out your weight in kilograms.
2 Find out your height in metres.
3 Divide your weight (in kilograms) by your height (in metres).
4 Then divide your answer by your height in metres again.

For example, someone who weighed 120kg (19 stone) and was 1.65m tall (5' 5") would have a body mass index of 44.

  • A body mass index of more than 27.5 is considered overweight.
  • A body mass index of more than 30 is considered obese.
  • A body mass index of more than 35 is considered morbidly obese.
Or use the chart below to find out your body mass index. Along the top of the chart, find the closest value to your height in metres. Down the left-hand side of the chart, find the closest value to your weight in kilograms. Then look on the chart to see where these two values cross - this is your Body Mass Index. For example, someone who is 1.65m tall and weighs 115 kilograms has a Body Mass Index of 42.



Surgery is appropriate for people with a body mass index of over 40. It can also be appropriate for people with a body mass index of over 35 if they have medical conditions related to the obesity such as diabetes or arthritis

In general, this procedure is not recommended for people under 18 or over 60 years.

It is possible to have the operation performed on the NHS or as private patient. For NHS patients your GP must obtain funding for the referral to Leeds for assessment, and for the treatment itself. The operation can be performed privately but the same selection criteria are used as for NHS patients and in all cases correspondence will be maintained with your GP. Details of the precise costs involved can be obtained from our contact number.