Weight-loss jabs have become the hottest talking point in modern health.
Scroll any news feed and you will see celebrities, influencers and ordinary people sharing dramatic before-and-after stories tied to medications that mimic the hormone GLP-1. The promise is simple: eat less, feel full faster, lose weight.
But according to nutrition scientist and author Dr Joanna McMillan, the real story may start somewhere far less glamorous. Not in a syringe, not in a clinic, but in your pantry.
'The body already has sophisticated systems for regulating appetite,' she tells the Daily Mail. 'What we have done over time is bypass many of them by shifting towards ultra-processed, industrialised ways of eating that are very low in fibre.'
Her new book, The Fibre Factor, explores what she describes as a forgotten cornerstone of metabolic health. And while she is careful not to dismiss prescription weight-loss drugs, she believes many people are overlooking a powerful natural ally in their pursuit of better appetite control.
Why fibre is back in the spotlight
Dr McMillan says fibre does far more than simply support digestion.
'It is influencing appetite hormones, gut microbes, blood sugar stability and inflammation,' she explains. 'It is really a master regulator of metabolic health.'
When fibre-rich foods reach the lower gut, they are fermented by beneficial bacteria. This process produces compounds known as short-chain fatty acids that help stimulate the release of satiety hormones, including GLP-1 and peptide YY.
These are some of the same hormonal pathways targeted by popular weight-loss medications. The difference, she says, is that food works more gently and more broadly.
'A medication amplifies one pathway very strongly. Fibre pulls multiple levers at once. It helps you feel fuller for longer, steadies blood sugar and supports the microbiome at the same time.'
She stresses that this does not mean fibre can replace prescription treatments for people living with obesity or diabetes. But for those who are otherwise healthy and looking to manage weight, dietary change is often a logical first step.
'There should always be a food-first approach. High-fibre, nutrient-dense eating patterns are consistently linked with easier appetite control and long-term weight management.'
How modern diets lost their fibre
One of the biggest surprises for many readers, Dr McMillan says, is just how dramatically fibre intake has shifted over time.
'When we look at traditional dietary patterns, our ancestors may have eaten close to 100 grams of fibre a day,' she explains. 'Today we are recommending about 25 to 30 grams, and many people are still falling short of even that.'
Public health data across many Western countries reflects a similar trend. Nutrition surveys consistently show that most adults do not meet recommended fibre targets, largely due to changing food environments and modern lifestyle pressures.
Industrial food production played a significant role in this shift. Refining grains to produce soft white bread and polished rice improved shelf life and convenience, but also removed the fibre-rich outer layers that once formed a staple part of everyday meals.
Over time, ultra-processed snacks, takeaway foods and packaged convenience options gradually displaced legumes, nuts, seeds, fruits and vegetables in many diets.
The growing popularity of low-carbohydrate eating patterns has also influenced fibre intake.
'Fibre itself is a carbohydrate,' Dr McMillan says. 'When people cut out carbs indiscriminately, they often remove wholegrains, legumes and fruits that provide important fibre diversity. In a sense we have thrown out the good with the bad.'
Five simple ways to boost your fibre this week
- Aim for 30 different plant foods across the week including vegetables, fruits, legumes, nuts, seeds and wholegrains
- Swap refined grains for wholegrain versions such as brown rice, barley or wholemeal sourdough
- Add legumes like lentils, chickpeas or black beans to meals to increase satiety and stretch protein portions
- Choose whole-food snacks such as fruit with nuts instead of packaged options
- Include vegetables in at least two meals each day to support appetite regulation and gut health
Nutrition experts increasingly emphasise that it is not carbohydrates themselves that are the issue, but the shift towards highly refined versions that digest rapidly and offer little satiety. Wholegrain and plant-rich dietary patterns, by contrast, are consistently associated with better metabolic health outcomes.
As awareness grows, researchers and clinicians are placing renewed focus on fibre as a foundational component of long-term health rather than a niche digestive aid.
The blood sugar connection many miss
Beyond fullness, fibre also helps stabilise energy levels in a way that can have real-world effects on cravings and snacking.
Rapidly absorbed refined carbohydrates can cause blood sugar to spike and then crash. This drop may trigger intense hunger and fatigue.
'If you are experiencing that mid-afternoon slump or reaching for snacks constantly, it may be related to the speed at which your meals are digested,' Dr McMillan explains.
'Fibre slows down carbohydrate absorption. You get gentler rises and falls in blood glucose, which helps maintain energy and reduces the drive to keep eating.'
Why the gut microbiome matters for your waistline
The surge in interest around gut health has also shone a light on fibre's metabolic role.
Dr McMillan describes gut bacteria as 'metabolic partners' that produce anti-inflammatory compounds and influence how the liver handles glucose and cholesterol.
'A diverse fibre intake helps nourish beneficial microbes. That has knock-on effects for appetite regulation, inflammation and even brain health.'
In practical terms, this means variety matters just as much as quantity.
'One simple target is aiming for around 30 different plant foods a week,' she suggests. 'It sounds like a lot, but when you start counting ingredients in salads, soups and breakfasts, it becomes surprisingly achievable.'
The social side of appetite suppression
While acknowledging the life-changing potential of GLP-1 medications for people with metabolic disease, Dr McMillan also raises concerns about unintended consequences.
'Food is more than fuel. It is about pleasure, culture and connection,' she says.
'Some people tell me they lose interest in cooking or social meals when their appetite is strongly suppressed. We need to ensure that any treatment approach still supports good nutrition and the joy of eating.'
She also believes society must be cautious about framing weight loss purely through an aesthetic lens.
'We should be striving for health, not chasing thinness at any cost.'
In an era increasingly shaped by pharmaceutical solutions, Dr McMillan believes the humble fibre-rich meal still deserves centre stage.
'Fibre is not just about digestion,' she says. 'It is influencing multiple systems in the body. When you increase plant diversity and whole foods, you are supporting your metabolism in ways that extend far beyond weight alone.'
Her message is simple. Before reaching for a prescription, it may be worth looking at what is already on your plate.