Results vs risks of theprocedures

Weight loss surgery is an effective way to lose weight, and keep it off.

Surgery is usually only considered after other weight loss methods have failed. It's more effective than conventional treatments, at least in the short term. On average, it produces a total weight loss of about 16%.

Some weight loss surgeries also help to resolve conditions associated with obesity, like type 2 diabetes, high blood pressure, sleep apnoea and hyperlipidaemia (high levels of fats in the blood).

Most studies of weight loss surgery only follow people up for a few years, so it's unclear how they do longer term. Some things we do know are:

  • adjustable gastric banding, while effective, produces slower weight loss compared to the more complex surgeries
  • for people with a very high BMI, a malabsorbtive procedure results in greater weight loss than a restrictive procedure
  • compared to diet and exercise, weight loss surgery results in increased life expectancy in people who are morbidly obese.


Surgery and conventional weight loss treatments both carry risks.

Some conventional weight loss diets can cause nutrient deficiencies, dehydration, weakness, fatigue, nausea, headaches and constipation.

With surgery, you need to consider the opportunity for increased health-related quality of life vs the risks of complications, and possible further surgery. 

General anaesthesia is riskier for people with a high BMI and/or diabetes.

Risks and complications of the surgery itself vary depending on the type of procedure you have.

Choosing a specialist

How to find a weight loss surgeon who specialises in these procedures.


Information is provided by HCF in good faith for the convenience of members. It is not an endorsement or recommendation of any form of treatment nor is it a substitute for medical advice, and you should rely on the advice of your treating doctors in relation to all matters concerning your health. Every effort has been taken to ensure the accuracy of the information, however HCF takes no responsibility for any injury, loss, damage or other consequences of the use of this information.