Adverts on your Insta feed. Friend groups on WhatsApp. Hidden behind the lettuce in your fridge. GLP-1 weight-loss injections like Ozempic, Mounjaro and Wegovy are everywhere, and next-gen drugs still in clinical trials, such as retatrutide, are a hot topic. Recent estimates suggest around half a million Australians are now using weight-loss injections – a tenfold increase since 2020.
Marketed as a medical breakthrough, weight-loss injections promise what dieting never could. They’re an “easy” fix to dropping weight, cutting appetite and silencing the food noise. And there is no doubt that many people have found them life-changing.
But now, a different kind of pressure is emerging. In a society increasingly equating health with weight loss, what happens to people who choose not to inject? What if – shock horror – they’re happy being the size they are?
Not to scale
First, it’s vital to remember that ‘health’ is about so much more than weight, stresses Dr Lily O’Hara, senior lecturer in public health at Griffith University and Secretary of Size Inclusive Health Australia. “You cannot look at someone and tell whether they’re healthy. There is no clear line between ‘healthy’ and ‘unhealthy’, and weight doesn’t predict health outcomes.”
And if that sounds counterintuitive, it might be. Because one of the most persistent myths in modern medicine is that body weight is a reliable indicator of wellbeing. Measures such as Body Mass Index (BMI) continue to be used as shorthand for health, despite decades of evidence challenging its validity. But when weight is treated as the cause of disease rather than a correlation, O’Hara says, it impacts how people are treated in every aspect of life, including healthcare.
“Research consistently shows that larger-bodied people experience delayed diagnoses, poorer quality care, and are less likely to seek medical help at all, often due to fear of being shamed or repeated incidents of being shamed and having their actual symptoms ignored,” she says. “Weight stigma – devaluation and dehumanisation of larger-bodied people – itself triggers chronic stress responses in the body, increasing cardiovascular risk independently of any physiological marker.”
Size matters
A report in the Canadian Medical Association Journal found that people treated unfairly because of their body size were more likely to suffer increased allostatic load – the wear and tear on the body that builds up when larger-bodied people are exposed to ongoing stress over time. This leads to increased inflammation, metabolic dysregulation, reduced immune function, and higher risk of heart disease, diabetes and depression. They also had a higher rate of deaths from all causes, regardless of BMI. Exposure to negative attitudes and beliefs about larger-bodied people is also associated with cortisol spikes, reduced self-regulation and increased binge eating.
Yet these factors are rarely accounted for when statistics link higher body weight with illness. “Correlation is repeatedly mistaken for causation,” says O’Hara. “When you take other factors like stigma, access to care and the risks of weight cycling – the cycle of losing and regaining weight – into account, many of those supposed ‘fat-caused’ risks disappear.”
And even if ‘thin’ did equate with ‘healthy’, GLP-1 drugs are not a magic bullet for life, O’Hara points out. The drugs were originally developed to assist people with diabetes by improving metabolic regulation, with weight loss a side-effect. “The mechanism is simple. Hunger signals are suppressed, food intake drops, and weight loss follows,” says O’Hara. But simplicity does not equal sustainability. “Most people who stop taking the drugs will regain rapidly.”
In other words, it doesn't make sense to frame larger bodies as inherently wrong and needing to be fixed through pharmaceutical intervention, rather than understood as part of human diversity.
Healthy change
“Human bodies aren’t infinitely malleable,” says Griffith University’s behaviour change and health psychology expert Professor Kyra Hamilton. “Much of physiology – muscle composition, oxygen capacity, body type – is shaped by genetic factors. Training and behaviour can optimise within biological limits, but cannot override them entirely.”
When weight loss is the only thing driving you, Hamilton argues, it makes it more difficult for you to change your behaviour long-term. “External motivators like calorie deficits or numbers on a scale are weaker drivers than internal ones,” she says. In fact, people are more likely to sustain behaviours that align with their values and identity than those driven by outside rewards or consequences.
So how do you start to make changes in your lifestyle if you don’t want those numbers to be your sole focus? Hamilton points to self-efficacy: the belief in your ability to build new habits. “People need confidence and resources to act,” she says. “Sometimes that’s about dispelling myths. For example, exercise doesn’t have to be intense or expensive. Walking regularly can be profoundly beneficial.”
She describes motivation in two phases: building intention and translating that intention into action. “Many people genuinely intend to move more or eat differently, but everyday obstacles – work, family, fatigue – derail them,” she says. Detailed planning, including anticipating likely barriers, improves follow-through. Monitoring progress and rewarding consistency, rather than outcomes, also strengthens habits.
Words that count
Language can play a positive role, too. Reclaiming the word “fat” as a neutral descriptor, says O’Hara, challenges the assumption that larger bodies are inherently broken or in need of correction. “It is not about denying health concerns, but about demanding dignity and evidence-based care regardless of size.”
Some of the strongest predictors of long-term health have nothing to do with weight at all, O’Hara points out – such as regularly meeting up with friends. “Social connection consistently outperforms physiological markers in predicting longevity, recovery after illness and mental-health outcomes.”
Hamilton believes that internal dialogue can either reinforce shame or build agency. “Self-talk matters,” she says. Instead of self-critical thoughts – “I’m too fat to swim” – she encourages shifting to more constructive, self-efficacy statements such as “I can do this.” She also recommends focusing attention on the activity itself: “If you’re walking, notice the air, the leaves, your breathing.” Staying present, she explains, helps reduce rumination.
Sometimes that means trying something new. In Hamilton’s work with midlife women, traditional activities such as yoga felt inaccessible or uncomfortable. “Alternatives like tai chi or mindful movement proved more sustainable, as they involve gentle strength, comfortable clothing and social connection without body scrutiny,” she says.
It’s hard to cut through the noise around weight-loss injections. The promise of the quick fix, the shiny adverts, the societal norms, and expectations around women’s bodies in particular are incredibly powerful. “There is strong evidence that at the individual level we can improve health and wellbeing through adding more movement, restorative rest and sleep, fruit and veggies, social connection, sense of purpose, and self-compassion, no matter what size you are,” says O’Hara.
Image captions (top to bottom):
- Dr Lily O'Hara
- Professor Kyra Hamilton
Published 30 April 2026
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