Parents are putting kids on the GAPS diet to ‘fix’ ADHD

When Jacintha Field’s son was two, she filmed a moment she still watches back today.

It was Easter at her brother’s house, during an egg hunt. What followed wasn’t a typical sugar-fuelled toddler’s tantrum.

‘He was craving more and more chocolate, repeating “more” through tears,’ she says.

‘What I was witnessing wasn’t defiance. It was a nervous system that couldn’t cope with what was happening in his body.’

That moment stayed with her: not as a parenting failure, but as a clue.

‘What I was seeing wasn’t behaviour that needed correcting,’ she says. ‘It was his body struggling.’

The GAPS diet parents are turning to

Field, a family and child counsellor, is far from alone in questioning whether food might be influencing her child’s emotional regulation and ADHD-type symptoms.

Across parenting forums, wellness circles and social media, one solution appears again and again: the GAPS diet.

Short for Gut and Psychology Syndrome, GAPS is a highly restrictive eating protocol developed by Dr Natasha Campbell-McBride.

It’s built on the idea that gut health directly influences brain function and behaviour. 

Families who follow it remove grains, dairy, refined carbohydrates and most processed foods, sometimes for months or years, replacing them with broths, fermented foods, meats and vegetables.

Glowing testimonials can be found everywhere online. 

Parents say GAPS ‘fixed’ their children’s ADHD. That it stopped meltdowns. That it transformed behaviour and focus when nothing else worked – even medication.

Australian GAPS websites are filled with stories of children who are said to be calmer, more regulated and easier to manage after starting the diet.

For parents desperate for answers, it’s compelling anecdotal evidence.

Why the idea feels so persuasive

Dr Antonio D’Costa, a paediatrician and trauma therapist, understands the appeal.

‘Parents are desperate for answers when their kid is struggling,’ he says.

‘ADHD medications work for many children, but they’re not magic. Diet feels more natural, more within a parent’s control.’

There’s also a kernel of science that makes the argument believable.

‘The gut-brain connection is real in other conditions,’ Dr D’Costa says.

‘Everyone knows about the ketogenic diet for epilepsy, which has decades of strong evidence. So parents think, “If diet can stop seizures, why not ADHD?”‘

The problem, he says, is where that logic leaps too far.

What the evidence shows

‘The evidence is mixed, but not non-existent,’ Dr D’Costa says.

He points to a 2020 study published in Frontiers in Psychiatry, which found elimination diets led to clinically relevant reductions in ADHD symptoms in about 60 per cent of children.

A 2011 randomised controlled trial in The Lancet found that symptoms returned when trigger foods were reintroduced.

‘But most of that research is on elimination diets in general, not GAPS specifically,’ he says. That distinction matters.

‘GAPS lacks rigorous controlled trials,’ Dr D’Costa adds.

‘There’s no evidence it works better than a standard, supervised elimination diet, or that it’s the diet itself rather than other changes driving improvement.’

Those other changes often arrive quietly alongside food.

‘When families change diet, they often also change routines, sleep, structure and stress levels,’ he notes.

‘Those things alone can dramatically improve regulation.’

Why restrictive diets can be risky

Dr Brooke Harcourt, senior paediatric and disability dietitian at Family Dietetics, says the conversation around restrictive diets needs to acknowledge something often overlooked: many neurodivergent children already struggle with food variety.

‘It’s estimated that around 70 per cent of the neurodivergent population will have some degree of difficulty accessing a wide range of foods,’ she says.

‘That can range from mild fussiness to extreme picky eating, or eating disorders such as avoidant/restrictive food intake disorder, or ARFID.’

That reality, she says, makes highly restrictive diets particularly fraught.

‘Highly restrictive diets decrease the range of foods that children can access,’ Dr Harcourt says.

‘This limits them socially – at school, at family meals – and can create another point of difference for them when negotiating times to eat.’

For children already managing sensory sensitivities, sameness can be protective.

‘Many neurodivergent children and teens seek sameness in the textures of their foods, because it gives them comfort and doesn’t add to sensory overload,’ she says.

‘Removing familiar foods can significantly increase stress.’

The nutritional cost of cutting major food groups

Dr Harcourt says the nutritional implications of long-term restriction are often underestimated by GAPS advocates.

‘Removing large food groups like grains, dairy and starchy vegetables can reduce access to key nutrients,’ she says.

‘That includes B vitamins like folate, minerals such as iron and zinc, and dietary fibres that are important for gut health.’

Carbohydrates, she adds, are not optional for growing bodies.

‘About 50 per cent of a child’s daily energy intake should come from carbohydrates,’ she advises.

‘Removing them can significantly limit the energy children have available for growth, learning and regulation.’

For Dr Harcourt, restriction should be used sparingly and with purpose.

‘Restrictive diets should be limited to situations where there are confirmed allergies or intolerances that would otherwise cause harm.’

Dr D’Costa shares that concern.

‘Growth faltering is the big one,’ he warns.

‘This is a critical window for brain development. Malnutrition can have irreversible effects.’

There are psychological risks, too.

‘Food restriction can create anxiety around eating and contribute to disordered patterns,’ he says.

‘And restrictive diets can become a distraction from the real issue.’

Where Jacintha’s story fits

‘At the beginning, if I’m honest, I swung the pendulum too hard,’ she admits.

‘When you finally connect the dots between food and regulation, it can feel urgent.’

She reduced gluten, limited dairy, avoided processed foods where possible, and became highly focused on what was going into her son’s body.

Over time, she realised that rigidity wasn’t sustainable – or helpful.

‘I’ve explored both extremes,’ she says. ‘Now I aim for a middle ground.’

That middle ground looks less like a strict protocol and more like an ongoing conversation. At home, she keeps far fewer processed foods and saves them for when they’re out. Baking together has become routine, with her son choosing what they make and taking it in his lunchbox.

‘That sense of choice matters,’ she says. ‘When food feels punitive, it doesn’t last.’

She’s also found alternatives that feel normal rather than restrictive – gluten-free pasta and tacos, spelt sourdough, specific low-sugar lollies and chocolates she knows don’t affect her son as strongly.

‘I don’t want him to feel left out,’ she says.

‘If he’s at a friend’s house and it’s easier to give him gluten, that’s okay. One meal is fine. An entire weekend can be more difficult, with much bigger consequences.’

Now 11, her son is actively involved in understanding his own body.

‘He’s learned how to read labels. It’s been incredibly empowering for him.’

When ‘bad’ behaviour is actually communication

Field avoids talking about ‘fixing’ behaviour.

‘Behaviour is communication,’ she says. ‘Self-regulation is a learned skill, not something children are born knowing how to do.’

Instead of reacting, she names what she sees.

‘I’ll say, “It looks like you’re self-regulating with food. Do you have some big emotions that need moving?”‘ she says.

‘Sometimes that opens a conversation. Sometimes it just softens the moment. Sometimes I get a very clear no. Either way, it brings awareness rather than shame.’

Transitions remain challenging, particularly after time spent at her father’s house, where her son eats more gluten and dairy.

‘When he comes back, there’s often an emotional release,’ she says. ‘Sometimes straight away, sometimes a day or two later.’

She’s noticed the impact can extend beyond mood.

‘There have been times it’s affected school attendance. It can take days to unravel.’

What helps most, she says, is connection.

‘When I notice a disconnection, we come back to the relationship first,’ she says. ‘Nature, when we can. Choosing outdoors. Small moments of “us” time.’

Looking back, Field believes the biggest shift wasn’t any single food change.

‘Education and awareness made the biggest difference,’ she says. ‘Helping my son connect how food, emotions and his body interact.’

She’s careful not to present her experience as a prescription.

‘I’m not sharing this as a blueprint – just one parent’s lived experience of paying attention and staying curious.’

For her, regulation has always been about safety.

‘When a child feels safe, the behaviour shifts on its own,’ she says. ‘Food was just one doorway. Connection was always the medicine underneath it.’

So what should parents take from this?

Dr D’Costa’s advice is deliberately unglamorous.

‘Start with the basics that have strong evidence and low risk,’ he says. ‘Consistent sleep schedules, predictable routines, emotional safety.’

If diet is explored, supervision matters.

‘Work with a paediatrician and ideally a paediatric dietitian,’ he says. ‘Monitor growth, set a clear timeline, be honest about whether it’s helping.’

Field agrees. She’s careful not to present her story as gospel.

And she makes one point clear: before labelling a child, she urges curiosity.

‘Sometimes what gets called “bad behaviour” isn’t behaviour at all – it’s a child’s body asking for help.’