A Finnish-Canadian research team has found evidence that diets high in ultra-processed food may be associated with changes in brain structures that regulate eating behaviour. The findings suggest a potential link between such diets and increased risk of overeating and obesity.
The study, conducted by researchers at the University of Helsinki and published in NPJ Metabolic Health and Disease, used brain scan data from around 30,000 middle-aged participants in the UK Biobank.
It revealed structural differences in brain regions related to appetite control among those with high consumption of ultra-processed foods.
“These foods appear to be associated with both reduced and increased cell density in specific brain areas,” said Annette Horstmann, professor at the University of Helsinki. “In some regions, lower neuron counts may indicate functional weakening, while denser cell areas, especially in the brain’s reward system, may point to inflammation.”
Ultra-processed foods include items such as sausages, sweetened beverages, ready meals, chocolate, ice cream, industrial baked goods, and instant noodles. The classification is based on the NOVA system developed at the University of São Paulo in Brazil, which ranks foods by processing levels.
“These products often contain chemically modified ingredients and additives to alter taste, texture, and shelf life, substances rarely used in home cooking,” said Arsène Kanyamibwa, a doctoral researcher involved in the study.
Common features of ultra-processed foods include high energy density, large amounts of sugar, fat, and salt, and synthetic additives like flavour enhancers and sweeteners. Ingredients can include chemically treated proteins and high-fructose corn syrup.
Researchers say more investigation is needed to determine whether the brain changes are a cause or consequence of diet. “It’s possible that chronic low-grade inflammation from the gut transmits signals to the brain, particularly to the hypothalamus,” Kanyamibwa explained.
Horstmann described the hypothalamus as a crucial hub for body-brain communication. “It regulates key bodily functions and food intake and is closely connected to the reward system that influences motivation and eating habits,” she said.
The researchers emphasised that while the data show a correlation, they do not prove causation. “We can’t yet say whether ultra-processed food causes these brain changes or whether individuals with certain brain structures are more likely to consume such foods,” Horstmann noted.
They also stressed the importance of following national dietary recommendations. “We are not nutritionists, and people should rely on official Finnish guidelines,” Kanyamibwa added.
HT
