Study Links Ultra-Processed Food Intake to Children’s Brain Reward Responses

An October 2026 study of 46 healthy-weight children found that those who ate more Ultra-processed foods had stronger brain responses to food cues in the dorsal striatum, a region involved in motivation, reinforcement learning and habitual behavior. Greater activation was also associated with subsequent increases in body mass index and body fat over a year.

The study, conducted by Kathleen A. Page and colleagues at Keck USC, used dietary estimates and functional MRI to examine the children, whose average age was 8.7. The researchers’ findings raise questions about how repeated exposure to highly rewarding foods might affect developing reward circuits, but they do not prove that diet caused the brain or body changes, or that the children had food addiction.

The article notes that stronger activation does not necessarily indicate unhealthy reward processing. The study was small, dietary intake was estimated, brain imaging was conducted once, and other factors could have influenced the results.

Earlier animal research offers one possible framework for interpreting the findings. Experiments led by Bart Hoebel and Nicole Avena found that repeated cycles of sugar access, bingeing and deprivation in rats produced escalating consumption, withdrawal-like responses and changes in brain chemistry. These results showed that specific patterns of sugar exposure can produce addiction-like adaptations in animals; they do not establish the same effects in children.

Research on addiction and eating has also examined the role of dopamine, which contributes to motivation and learning, and endogenous opioids, which are involved in reward. Epigenetic changes—alterations in gene regulation that do not change the DNA sequence—have been observed in reward circuits after exposure to addictive drugs. Animal studies suggest highly palatable diets may produce similar changes, though the article emphasizes that such effects are not necessarily permanent.

Ultra-processed foods vary, and the questions raised by the research include which foods, exposures and developmental periods might be associated with lasting effects. The article calls for further study of factors such as genetic vulnerability, early stress, food insecurity, and combinations of sugar and fat. It also stresses that obesity and addiction-like eating are not the same: some people with obesity do not show addictive eating, while some people who do show such behaviors are not obese.

Sources: Psychology Today.