Am I Eligible for Weight Loss Surgery?

Key takeaways

• Eligibility isn't decided by BMI alone. Your medical history, general health and any previous attempts to manage your weight all factor into the assessment.
• The commonly used threshold is a BMI of 35 or above, or 30 to 34.9 alongside an obesity-related health condition such as high blood pressure or type 2 diabetes.
• Dr Greenslade generally works from a minimum BMI of 35, assesses patients below that figure case by case, and rarely operates below BMI 32.
• A GP referral is needed to book a consultation, with an added step for patients over 65.

• A consultation is where your full health picture, not just a number, shapes whether surgery and a longer-term treatment plan could be right for you, with ongoing support available well beyond the day of surgery.

Eligibility for weight loss surgery, explained

Eligibility for weight loss surgery is one of the first things people want to understand before booking an appointment, but there is rarely a simple yes or no answer. BMI is part of the picture, but so are your overall health, weight history, and what you have already tried to manage your weight.

At Brisbane Bariatric Centre, Dr Justin Greenslade looks at the whole person rather than relying on a number alone. If you have been searching online trying to work out if surgery could be an option for you, this guide explains the main factors considered during that assessment, so you can head into your first consultation with a clearer idea of what to expect.

What are the general criteria for weight loss surgery in Australia?

Across Australia, the starting point most surgeons work from is body mass index, or BMI. The commonly cited threshold is a BMI of 35 or above, or 30 to 34.9 alongside an obesity-related health condition such as high blood pressure or type 2 diabetes. This reflects updated guidance from Australian and international bariatric societies, which increasingly looks at the bigger picture. The health issues linked to excess weight can matter just as much as the number on the scale when deciding if surgery may be appropriate. Some surgeons and older resources still work from the traditional benchmark of a BMI of 40, or 35 with a related condition, so the figure you come across can vary depending on where you look.

BMI is used because it gives a quick, consistent way to screen and compare, not because it captures everything relevant about someone's health. It doesn't account for muscle mass or the day-to-day impact excess weight has on a person's life, which is why it works as a starting point for discussion rather than a final verdict.

Dr Greenslade's own approach sits close to the modern standard. He generally works from a minimum BMI of 35, considers patients below that figure case by case, and rarely operates below a BMI of 32. Check your own number with the BMI calculator on our eligibility page before booking.

What health conditions can affect eligibility?

Eligibility isn't just about the BMI number itself. It's also shaped by weight-related health conditions, especially when BMI sits below 35. Common examples include type 2 diabetes, sleep apnoea, high blood pressure, high cholesterol, osteoarthritis, PCOS, and reflux.

These conditions matter clinically because they show excess weight is already causing measurable harm, not just posing a future risk. That changes the risk-benefit calculation: the ongoing harm of these conditions can outweigh the risks of surgery, which is why a lower BMI threshold may be accepted, particularly when other weight loss approaches haven't produced lasting results.

What other factors does Dr Greenslade consider?

BMI and medical criteria are the starting point, but they are far from the whole assessment. You need to be at least 17 to be considered, and anyone under 18 will need to attend with a parent or guardian. Patients over 65 follow a slightly different pathway. Their GP sends a referral through for Dr Greenslade's opinion before an appointment is booked, since surgical and anaesthetic risk can change with age. That extra step helps confirm surgery is still the safest option for each individual, rather than assuming age alone rules it out.

Beyond the medical picture, Dr Greenslade also looks at how ready someone feels for the change surgery brings. This includes psychological readiness and realistic expectations, previous attempts at losing weight through diet, exercise or medication, and a genuine willingness to commit to lifestyle changes long after the procedure itself. Attending follow-up appointments and staying connected with support matters too, since long-term outcomes depend largely on the years of care that follow surgery, with the procedure itself playing only a starting role.

A quick eligibility check

These five questions can give you a rough sense of where you stand. This isn't a clinical assessment, and only a consultation with Dr Greenslade can confirm if surgery is right for you.

• Is your BMI 35 or above?
• Is your BMI between 30 and 34.9, alongside a condition such as type 2 diabetes, sleep apnoea or high blood pressure?
• Have diet, exercise or weight loss medication not delivered lasting results for you?
• Are you 17 years of age or older?
• Are you ready to commit to follow-up care and long-term changes to how you eat?

If you answered yes to most of these, it is worth booking a consultation to talk things through properly.

Do I need a GP referral for weight loss surgery?

Yes, a referral from your GP is needed to see Dr Greenslade. If you are over 65, that referral needs to go through in advance so he can review your case before an appointment is confirmed. For patients living outside Brisbane, our page for rural and interstate patients covers what to expect if you are travelling for care, including telehealth appointments and support with travel costs.

Private and public pathways into weight loss surgery are not the same. Queensland Health runs a statewide public bariatric service with criteria considerably narrower than a private referral: patients generally need to be aged 18 to 65, have type 2 diabetes managed with two or more medications, an HbA1c above 6.5 per cent despite that treatment, a BMI over 35, and a referral from a hospital specialist rather than a GP. Private pathways, including consultations with Dr Greenslade, do not require a diabetes diagnosis and can be accessed through a standard GP referral.

What if I don't meet the BMI threshold?

A BMI under 35 doesn't automatically rule surgery out. Dr Greenslade still looks at these patients' cases on a case-by-case basis, weighing up health conditions, weight history and how excess weight affects daily life. He rarely operates below a BMI of 32, so if your number sits between 32 and 35, a conversation is generally worth having rather than assuming the door is closed. Plenty of people rule themselves out based on a number read online, when a short consultation would have given a clearer answer.

Who is weight loss surgery NOT right for?

Weight loss surgery involves a long-term commitment, so being upfront about readiness tends to lead to better outcomes for the people who do go ahead. Surgery may need to wait, or need more groundwork first, for those with:

• Active mental health conditions that haven't yet been assessed or treated
• Current alcohol or substance dependency
• Uncontrolled medical conditions, including heart disease and other risk factors that need stabilising beforehand
• Eating habits or lifestyle patterns that suggest more preparation is needed before committing to the changes surgery requires long-term

None of this is about ruling people out for good. In most cases, it's about identifying what needs attention first, so that when surgery does go ahead, someone has the right support in place around them. If any of this sounds like your situation, it's still worth talking to your GP or Dr Greenslade about the right order of steps.

What happens if I think I might be eligible for bariatric surgery?

1. Check your BMI using the calculator on our eligibility page.
2. Talk to your GP and ask for a referral to see Dr Greenslade.
3. Book a consultation, where a full assessment happens, taking in your whole health picture rather than a single number.

Call our team on 07 3324 0015 or make an enquiry online to get started.

Frequently asked questions

Do I need private health insurance for weight loss surgery in Brisbane?

Not necessarily. Some policies cover bariatric surgery, though cover and waiting periods vary between funds. Options without insurance include self-funding, payment plans, and accessing superannuation early. See our pricing page for more.

What types of weight loss surgery does Dr Greenslade offer?

Dr Greenslade performs three main procedures, and which one comes up in your consultation depends on your medical history, existing health conditions and what you're hoping to achieve:

• Sleeve gastrectomy — also known as gastric sleeve surgery, removes around two-thirds of the stomach, leaving a smaller tube-shaped stomach. No bowel bypass and no implanted device involved.
• Gastric bypass — creates a small stomach pouch connected to the small bowel, so food bypasses most of the stomach. Often considered where conditions like type 2 diabetes or reflux are present, and involves lifelong nutritional monitoring.
• Single anastomosis gastric bypass — a variation of gastric bypass using one intestinal connection rather than two. Generally not recommended for people with existing reflux or GORD.

How long is the wait for bariatric surgery in Queensland?

It depends on the pathway. Public surgery through Queensland Health can involve a long wait, given limited places and narrow entry criteria, while private surgery generally moves faster once a referral is in place.

Can teenagers have weight loss surgery in Australia?

Yes, in some cases. Dr Greenslade accepts patients from the age of 17, with anyone under 18 attending consultations alongside a parent or guardian.

What is the difference between public and private bariatric surgery?

Queensland Health's public service is free but narrow, requiring a diabetes diagnosis, a specialist referral, and an age limit of 65. Private surgery is more broadly accessible, generally needs only a GP referral, and doesn't require a diabetes diagnosis, though cost varies depending on insurance cover.

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