Thinking about bariatric surgery for weight loss? Here's what to consider

Bariatric surgery is weight-loss surgery to treat obesity or reduce weight-related health complications. These surgeries alter the structure of the digestive tract, which helps reduce hunger.

As dietitians and a bariatric medicine doctor, we often get asked when an adult might consider surgery for weight management.

The short answer is people may be eligible for surgery if they have a body mass index (BMI) over 40 (defined as severe obesity), or if their BMI is less than 40 but they have medical complications such as diabetes.

But bariatric surgery is not suitable for everyone with obesity. Here are some factors to consider if you’re thinking about it.

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How is your weight impacting your health?

The Edmonton Obesity Staging System is used to classify the physical, medical and wellbeing impairment of people with obesity. Stage zero means no impairment, while stage four – the highest category – indicates severe impairment.

People in stages three and four commonly have major health issues, higher medication and health service use, need longer periods of treatment to achieve their weight-related goals and are at greater risk of complications following surgery.

People eligible for bariatric surgery will typically be in stage three or four.

How does bariatric surgery work?

Bariatric surgery procedures reduce stomach volume. Most are keyhole procedures, where small cuts are made in the abdomen and tiny cameras inserted to guide the operation.

Bariatric surgery makes people feel fuller. Combined with changes in dietary intake, it typically leads to long-term weight reduction of 20% to 40% of the person’s starting weight.

This weight loss can help improve high blood pressure, type 2 diabetes, sleep apnoea and fatty liver disease.

However, there are risks from surgery which also need to be considered, including vomiting, constipation, increased bowel movements, as well as longer-term risks such as reflux, hernia, malnutrition and small bowel obstruction.

Alternative approaches to weight management

Before considering surgery it’s important to talk to a GP or obesity specialist about all suitable evidence-based approaches to improve your weight-related health, including very low energy diets.

Specific medications approved for weight management in Australia are available but can be costly. Medication can help achieve a 5-10% weight reduction, although results and side-effects vary, so regular review is needed.

While people with moderate obesity may lose enough weight to improve their health through diet alone, for severe obesity, diet may not be enough.

Weight management is a lifelong journey, so over time, a person might try numerous approaches and review their progress towards their goals at each stage. This includes interventions to improve nutrition, physical activity, fitness, mental health, and/or medications for health risk factors, appetite and complications from carrying excess body weight.

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A word about stigma

Weight stigma and bias are negative attitudes, beliefs or discrimination based on a person’s weight. This can occur in both public and private health settings and prevent people getting the medical care and support to improve their weight-related health.

It’s important for people to find a doctor they can work with to develop a comprehensive management strategy for them. That plan may, or may not, include bariatric surgery.

Weight stigma can also prompt people to discontinue health care after surgery because they feel bad, or are made to feel bad, about their weight or surgical results.

When should bariatric surgery be considered?

Access to bariatric surgery through public hospitals in Australia is currently very limited, unless you have private health insurance that covers bariatric procedures.

Other considerations are:

1) What weight-related outcomes are you hoping for?

From improved health to fewer medications, remission of type 2 diabetes or better physical mobility, having a clear understanding of potential positive post-surgery impacts helps with monitoring progress.

It also helps decide whether other approaches could be tried first, such as medications.

2) What are advantages and disadvantages of bariatric surgery?

Bariatric surgery has both positive and negative implications. While body dysmorphia (negative feelings about your body) can improve post-surgery, it might not.

Other common concerns which you should be prepared for include difficulty eating out with friends, potential hair loss, excess skin, bone and muscle loss. Special considerations may be needed for those planning future pregnancy to ensure they’re getting enough nutrients.

3) Can the person considering surgery give fully informed consent?

A “yes” means the person has had all their questions answered, fully understands that permanent weight loss is not guaranteed and that lifelong follow-up is needed to optimise their health.

While most people do lose substantial amounts of weight, weight can rebound depending on the type of and time since surgery, presence of emotional or disordered eating, and consumption of larger food portions.

4) Can you access adequate post-operative support?

The first year after surgery requires more intensive follow-up involving surgeons, GPs, obesity specialists and allied health providers. Ongoing follow-up helps to monitor health improvements, nutritional status, mental health and any weight regain.

Bariatric surgery may be the right choice for people with obesity where the benefits are clear, the time is right, and to optimise their health and wellbeing. But preparation and long-term support are important. The best place to start is to talk to your GP.

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