Could eating less sugar help manage ADHD symptoms? An expert explains

ADHD diagnoses have risen in recent years, with the NHS estimating that 2.5 million people in England have attention deficit hyperactivity disorder as of May 2025.

The factors behind this surge have often been the subject of heated debate, and Channel 4's new documentary The Great ADHD Myth?, hosted by psychiatrist and Trust Me, I’m a (Junior) Doctor author Max Pemberton, has sparked even more discussion. The provocative investigation argues that ADHD is over-diagnosed and over-medicalised.

Of course, it's received significant backlash. The Guardian's TV critic Lucy Mangan called it ‘the most controversial show of the year’, writing that ‘this is a documentary that will incense and offend some of its viewers, and its scepticism regarding ADHD is clear from the outset’. The charity ADHD UK also published a strongly critical response. ‘We watched. We said we’d be fair,’ the charity wrote. ‘Here is our verdict. ADHD is not a myth. It is not a social construct… We have already complained to Ofcom. A fuller submission follows, built on the impact data you give us below.’

But beyond the debate over diagnosis and medication, the documentary also raises a practical question that's worth considering: could everyday habits – including diet – affect the severity of ADHD symptoms?

Can diet affect ADHD symptoms?

The idea that sugar and hyperactivity are linked has deep roots, so sugar is an obvious place to start. Neurophysiological psychologist and founder of The Key Clinic Sarah Warley, who featured on the show, is clear that sugar does not cause ADHD or anxiety; however, she believes ‘it can fuel the symptoms of both, including in those without a diagnosis’.

‘Riding a roller coaster of blood sugar spikes and crashes affects energy, mood, concentration and emotional regulation,’ she says.

Warley argues that, for people with ADHD, blood sugar spikes and crashes may be mistaken for, or add to, existing symptoms.

‘When blood sugar drops rapidly after a spike, the body releases cortisol and adrenaline. These are the same stress hormones that fuel anxiety, irritability and the fight-or-flight response,’ she continues.

‘For adults or children with ADHD, this blood sugar instability can look like restlessness, anger, inability to concentrate, emotional meltdowns and fatigue. These symptoms are then attributed to the ADHD itself rather than to what was eaten for breakfast,’ she says.

But the scientific evidence linking diet and ADHD is still developing and remains limited.

A 2014 Korean study found that children with ADHD were more likely to eat a dietary pattern high in snacks and processed meat. However, the study showed an association rather than proving that these foods caused ADHD.

A larger 2019 study followed almost 3,000 children between the ages of six and 11. It found no association between consistently high sugar consumption and developing ADHD during that period. The researchers suggested that higher sugar intake could sometimes be a consequence of ADHD – for example, because children may gravitate towards quick sources of energy – rather than a cause.

One review, Warley points out, proposed that chronic high sugar intake may actually blunt dopamine signalling in ways that contribute to ADHD symptoms. But the authors describe this as a hypothesis requiring further research, rather than an established finding.

So, should you ditch the sugar?

There is currently no evidence-based ‘ADHD diet’ and reducing sugar is not a recognised treatment for the condition.

Dietary changes should not replace prescribed medication or other professional support, and anyone considering changing or stopping ADHD medication should speak to their doctor first.

That said, improving the overall quality of your diet can be a sensible general health goal. Warley says the answer is not to make extreme changes or follow a highly restrictive diet.

‘It’s important not to be extreme with any diet changes and to ensure the food you eat is nutritionally varied,’ she says. ‘A simple place to start is by looking at your plate. If it is mostly beige – bread, pasta, cereal, biscuits and crisps – try adding more variety. A handful of berries on porridge, some red pepper sticks with lunch or broccoli with dinner are all small, manageable changes.’

And when it comes to sugar, Warley recommends reducing rather than banning it completely.

‘The practical step regarding sugar is not to ban it completely, but to reduce the frequency of exposure. Try gradually taking it down and you will find that your taste buds will begin to find less sugary food sweet,’ she says.

The bottom line

No, eating a pack of chocolate biscuits isn’t going to give you ADHD. And no, swapping cereal for eggs isn’t going to magically cure it, either.

While it’s easy to point to a specific food or ingredient, many factors can play a role in how symptoms present, including sleep, stress, emotional wellbeing, and the timing of meals. There is no single diet that can treat ADHD, and sugar is not the cause of the condition.

The takeaway isn't particularly glamorous – eat regularly, add a little more variety, cut back on added sugar if you can, and keep taking prescribed medication unless your doctor tells you otherwise.