Is weight really just about willpower?

No, and being told it is has held a lot of people back. Body weight is strongly shaped by biology — genetics, hormones, appetite signalling, medications, sleep, stress and your environment — not just by effort. That's exactly why supported approaches work better than going it alone, and why medicines and surgery exist at all: they change the underlying biology rather than just asking you to try harder. Australian guidance treats obesity as a chronic health condition to manage long-term, not a character flaw.

How is whether I'd benefit from treatment actually decided?

It's not BMI alone. In Australia, weight is assessed using BMI together with waist circumference and your overall health — including conditions like type 2 diabetes, high blood pressure or sleep apnoea. Two people with the same BMI can sit in very different places once health is factored in. The starting point is a conversation with your GP about your whole picture, not a single number on a chart.

Should I ask about Ozempic, Wegovy or Mounjaro?

These newer weight-management medicines (semaglutide, tirzepatide and similar) can be effective for the right person, and they're a reasonable thing to ask your GP about. A few honest points: in Australia they're approved for weight management above certain BMI thresholds but are generally a private cost, not subsidised, for weight loss. They have side effects and aren't suitable for everyone, and they work best alongside lifestyle change, not instead of it. Your GP can tell you whether you fit the approved group and what it would realistically involve — including cost.

When is weight-loss surgery considered?

Surgery is generally considered for people with a BMI of 40 or more, or 35 or more when there are weight-related health problems such as type 2 diabetes — usually after other approaches have been tried. It can produce large, durable weight loss and improve conditions like diabetes, but it's a major decision that requires lifelong follow-up, vitamin and mineral supplements, and permanent changes to how you eat. It's a powerful tool, not a shortcut, and the choice belongs with you, your GP and a surgical team.

What's the difference between the gastric sleeve and the gastric bypass?

These are the two most common weight-loss operations in Australia (the older adjustable band is now rarely done). The gastric sleeve removes part of the stomach to make it smaller; the gastric bypass also reroutes part of the small intestine. The bypass often achieves greater weight loss and can be better for reflux and diabetes, while the sleeve is a simpler operation — but each has different risks and trade-offs. There's no single 'best' one; the right choice depends on your health and priorities, worked out with your surgeon. The decision aid below lays them side by side.

Decision aid

Weight management — medications and weight-loss surgery options

By Dr HB Lo, FACRRM Reviewed 14 June 2026 4 min read

General information to help you prepare for your GP — not a diagnosis, not personal medical advice. It doesn't replace a consultation, and using it doesn't create a doctor–patient relationship.

If you've decided to do something about your weight, you've probably already tried hard — often for years. The most useful thing to know is that weight is far more about biology than willpower, and there are now several real tools, not just "eat less, move more."

In Australia the foundation for everyone is supported lifestyle change. Beyond that, two further options exist for the right person: weight-loss medicines, and weight-loss (bariatric) surgery. Each suits different situations, and none is a quick fix or a moral test.

This guide lays out how those options are weighed, so you can take clear questions to your GP rather than navigating a confusing, often judgemental landscape alone.

You’ve probably already tried hard — this isn’t about trying harder

Most people arrive at this conversation carrying years of effort and a fair amount of shame. Diets that worked then stopped. Advice that boiled down to “just eat less.” A sense that the weight is a personal failing. It helps to put that down at the door, because it isn’t accurate. Body weight is driven far more by biology than by willpower — genetics, hormones, appetite signalling, medicines, sleep and environment all pull on it, as the RACGP obesity position statement recognises in treating obesity as a chronic condition to manage, not a moral test.

That reframing matters, because it changes the question. It’s no longer “why can’t I do this?” It’s “which of the available tools fits my situation?” There are now several, and this guide walks through how each is weighed.

How “would I benefit?” is actually assessed

It isn’t BMI on its own. In Australia, weight is assessed using BMI together with waist circumference and your overall health — whether you also have type 2 diabetes, high blood pressure, sleep apnoea or other weight-related conditions, as HealthDirect explains. Two people at the same BMI can land in very different places once health is factored in. So the starting point is your whole picture, not a single number.

Step one, always: supported lifestyle change

Whatever else is added, supported lifestyle change is the foundation for everyone, per Therapeutic Guidelines and the RACGP. The honest version of this isn’t “eat less, move more” shouted louder — it’s structured, realistic support: a dietitian, an achievable eating pattern, movement you’ll actually keep up, sleep, and help with the habits and stresses that drive eating. Lifestyle change is also the layer that every medicine and every operation is added on top of, not replaced by. It keeps mattering at every step.

Weight-loss medicines — useful, but read the fine print

Newer weight-management medicines have genuinely changed what’s possible. The most talked-about are the GLP-1-based medicines (such as semaglutide and tirzepatide), which act on appetite signalling and can produce meaningful weight loss for the right person, as Australian Prescriber summarises.

A few honest points worth holding together:

In Australia these medicines are TGA-approved for weight management above certain thresholds (a BMI of 30 or more, or 27 or more with a weight-related condition), but for weight loss they’re generally a private cost — not subsidised.
One narrow exception is on the horizon: in late 2025 the medicines advisory committee recommended a limited subsidy for semaglutide for people who have already had a cardiovascular event and have a BMI of 35 or more (32.5 or more for people of Asian, Aboriginal or Torres Strait Islander background). As of mid-2026 that was recommended but not yet finalised as an actual listing, and it doesn’t cover weight loss in general.
They have side effects (commonly nausea and gut upset), aren’t suitable for everyone, and work best alongside lifestyle change rather than instead of it.

Whether one of these fits you — and what it would realistically cost and involve — is exactly the kind of thing the weight-management decision aid below is built to help you take to your GP. It’s a discussion to have with your doctor, not a medicine to seek out or stop on your own.

Weight-loss (bariatric) surgery — a major tool for the right person

For people with more severe obesity, surgery can produce large, durable weight loss and substantially improve conditions like type 2 diabetes. It’s generally considered for a BMI of 40 or more, or 35 or more with weight-related health problems, usually after other approaches, per HealthDirect’s guide to bariatric surgery and the Australian & New Zealand Metabolic and Obesity Surgery Society.

The two most common operations in Australia are:

The gastric sleeve (sleeve gastrectomy) — part of the stomach is removed to make it smaller. It’s the most commonly performed weight-loss operation in Australia, as HealthDirect describes.
The gastric bypass — the stomach is made smaller and part of the small intestine is rerouted. It often achieves greater weight loss and can be better for reflux and diabetes, per HealthDirect.

The older adjustable gastric band is now rarely done, accounting for a tiny fraction of operations, per the Better Health Channel. Critically, surgery is a tool, not a cure: it requires lifelong follow-up, ongoing vitamin and mineral supplements, regular blood tests, and permanent changes to how you eat. Choosing between the sleeve and the bypass is a real trade-off, which the weight-loss surgery decision aid below sets out side by side so you can prepare the questions for your GP and surgeon.

The questions worth taking in

Looking at my whole picture — not just BMI — what would treatment realistically change for me?
What support is available to help me with the lifestyle foundation, beyond being told to try harder?
Do I fit the approved group for a weight-loss medicine, and what would it cost and involve?
If surgery were on the table, which operation might suit me, and what does lifelong follow-up actually mean?

These are questions, not conclusions. The aim is to decide with your GP.

What this is, and is not

This is general information to help you prepare for your GP — not a diagnosis, and not personal medical advice. It doesn’t tell you to start, stop or change any medicine, or to have or avoid surgery; those decisions are made with your own doctors. For trustworthy Australian background, see HealthDirect and the Better Health Channel.

Related on this site: the obesity and metabolic syndrome explainer goes deeper on the condition, and the type 2 diabetes treatment decision aid covers the closely linked decision that often arrives alongside it.

If you want a thorough, unhurried work-up of your own metabolic picture, you can work with Dr Lo.

Author: Dr Hoe Bing Lo — AHPRA MED0001212640 · FACRRM. Fun Doctors Pty Ltd · ABN 83 404 436 330.

Tools to take to your GP

Each runs in your browser — nothing you enter is stored or sent anywhere. They help you prepare the questions and print a one-page summary to bring to your appointment. They don't diagnose or recommend a specific treatment.

Frequently asked questions

Is weight really just about willpower?

No, and being told it is has held a lot of people back. Body weight is strongly shaped by biology — genetics, hormones, appetite signalling, medications, sleep, stress and your environment — not just by effort. That's exactly why supported approaches work better than going it alone, and why medicines and surgery exist at all: they change the underlying biology rather than just asking you to try harder. Australian guidance treats obesity as a chronic health condition to manage long-term, not a character flaw.
How is whether I'd benefit from treatment actually decided?

It's not BMI alone. In Australia, weight is assessed using BMI together with waist circumference and your overall health — including conditions like type 2 diabetes, high blood pressure or sleep apnoea. Two people with the same BMI can sit in very different places once health is factored in. The starting point is a conversation with your GP about your whole picture, not a single number on a chart.
Should I ask about Ozempic, Wegovy or Mounjaro?

These newer weight-management medicines (semaglutide, tirzepatide and similar) can be effective for the right person, and they're a reasonable thing to ask your GP about. A few honest points: in Australia they're approved for weight management above certain BMI thresholds but are generally a private cost, not subsidised, for weight loss. They have side effects and aren't suitable for everyone, and they work best alongside lifestyle change, not instead of it. Your GP can tell you whether you fit the approved group and what it would realistically involve — including cost.
When is weight-loss surgery considered?

Surgery is generally considered for people with a BMI of 40 or more, or 35 or more when there are weight-related health problems such as type 2 diabetes — usually after other approaches have been tried. It can produce large, durable weight loss and improve conditions like diabetes, but it's a major decision that requires lifelong follow-up, vitamin and mineral supplements, and permanent changes to how you eat. It's a powerful tool, not a shortcut, and the choice belongs with you, your GP and a surgical team.
What's the difference between the gastric sleeve and the gastric bypass?

These are the two most common weight-loss operations in Australia (the older adjustable band is now rarely done). The gastric sleeve removes part of the stomach to make it smaller; the gastric bypass also reroutes part of the small intestine. The bypass often achieves greater weight loss and can be better for reflux and diabetes, while the sleeve is a simpler operation — but each has different risks and trade-offs. There's no single 'best' one; the right choice depends on your health and priorities, worked out with your surgeon. The decision aid below lays them side by side.

Source quality

Sources grouped by evidence tier. Australian primary tier first; international where Australia is silent or lagging. How tiers work.

T1 AU primary 9 sources

If you want a thorough, unhurried work-up of your own — not a generic answer — you can work with Dr Lo.