Struggling to focus? What you eat might be affecting your brain

Do you find hard to concentrate? Sleep, hydration and physical activity are often part of the picture, but researchers are looking into another potential factor: diet.

While studies have already associated higher consumption of ultra-processed foods (UPFs) with increased risk of health conditions like heart disease and type 2 diabetes, external, new research suggests it could also be linked to changes in brain health and function.

Emerging research suggests they could.

A 2026 study of more than 2,100 adults, external found that people who ate more ultra-processed foods tended to perform worse on tests measuring attention and processing speed.

Lead author, Monash University's Dr. Barbara Cardoso, says, "For every 10% increase in ultra-processed food a person consumed, we saw a distinct and measurable drop in a person's ability to focus.

"To put that in perspective, a 10% increase in UPFs is roughly equivalent to adding a standard packet of chips [crisps] to your daily diet."

Like most studies in this area, this one was observational, which means researchers can only identify links. As Cardoso and her team stress, it doesn't help determine cause and effect.

While the findings don't prove UPFs cause changes in brain health or, more specifically, poor concentration, they fit into a wider body of research that has found associations between higher UPF consumption and poorer cognitive outcomes.

There's growing research linking UPFs with other changes in the brain, too.

One review suggested 'chronic consumption' of UPFs was linked to depression. Another suggested a higher risk of Alzheimer's disease, external, while others have linked UPFs with dementia, external and cognitive decline, external.

A study of 33,650 people by the University of Helsinki, external also found an association with high consumption of UPFs and structural changes in the nucleus accumbens, a key part of the brain's reward system, and the hypothalamus, which regulates eating behaviour.

"These two regions are incredibly involved in how we eat – from hunger to satiety, pleasure and reward," explains one of the report's authors, doctoral researcher Arsene Kanyamibwa.

"That's why we suggested there may be a vicious cycle: we don't know which comes first, but it seems that maybe if you eat more UPFs, you want to eat more UPFs."

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There's no concrete evidence showing that ultra processing alone makes us crave particular UPFs, says Kanyamibwa. His work – like the vast majority in this field – shows association, not cause and effect.

There is, however, enough research to suggest that foods high in sugar, fat and salt – like pizza and doughnuts – promote overeating through activating the same reward pathways in the brain as certain drugs, external.

But food and drugs are not the same, he points out (we need food for survival, after all) and "craving alone doesn't equal addiction."

The concept of 'food addiction' is hotly debated in the scientific community, Kanyamibwa says.

Some argue that labelling foods as addictive could remove a sense of agency or mislabel complex psychological behaviours.

But cravings might in part be caused by the make-up of UPFs, which are typically engineered to be highly palatable and easier to eat, causing rapid digestion and hitting the brain's reward system faster.

"It's possible that consistent exposure to UPFs affects the brain in ways that make this type of eating more habitual – and extreme processing might well be one of the reasons we have so many people showing signs of overeating [them]."

It's about paying attention – not panicking.

The research in this area is still in its infancy and more studies are needed on humans rather than animals, says Kanyamibwa.

There's a practical element too: it's unrealistic in 2026 to cut out UPFs entirely. They're embedded in our food system and for many are an affordable and convenient choice, accounting for more than half the calories consumed by the average UK adult, external.

Plus, not all UPFs are created equal. Some, like baked beans and wholegrain cereals, are a good source of fibre.

Kanyamibwa is looking to a future where the link between UPFs and brain health is more concrete.

"I think it's on us scientists to design stronger studies, because there is still a lot of uncertainty on this concept.

"Then eventually we need to convince policymakers to create the environment where healthier choices are affordable and accessible."

What we can do is choose more foods associated with better brain health, says dietitian Nichola Ludlam-Raine, author of How Not to Eat Ultra-Processed.

She recommends extra virgin olive oil, which is rich in polyphenols and monounsaturated fats associated with lower cardiovascular and cognitive decline risk, external, as well as walnuts, which have been associated in some studies with better cognitive outcomes and lower risk of cognitive decline, external.

Prioritising protein and fibre at meals is key, as is eating regularly. This will help to stabilise blood glucose and prevent snacking when you're not actually hungry.

Instead of banning "high-reward" foods, she suggests planning them in as part of a balanced diet to limit "binge-restrict cycles".

For some easy UPF swaps, Ludlam-Raine suggests ditching high-sugar, flavoured yoghurts and pre-packaged cereal bars in favour of Greek yoghurt with fruit and mixed seeds, oatcakes with banana and nut butter, and medjool dates stuffed with nut butter and dark chocolate.

"Ultimately, this isn't about authority or self-control in isolation," she adds. It is not a question of willpower.

"A balanced approach, where foods high in fat, sugar and salt are eaten consciously and in moderation within an overall nutrient-dense dietary pattern, is more sustainable than rigid rules."

Originally published September 2026.

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