Childhood Junk Food May Permanently Alter Brain and Eating Habits, Study Warns

Washington DC (US), May 22, 2026, BNN Web Staff: Regular consumption of high-fat and high-sugar junk food during childhood could cause long-lasting changes in the brain and eating behaviour, even if healthier food habits are adopted later in life, according to a new study conducted by researchers at University College Cork.

The research, published in Nature Communications, found that unhealthy diets early in life may disrupt brain regions responsible for appetite control and feeding behaviour, potentially increasing the risk of obesity and unhealthy eating patterns in adulthood.

Scientists from APC Microbiome Ireland, a major research centre based at the university, said modern children are constantly exposed to heavily processed foods rich in fat and sugar through school events, celebrations, sports activities, and aggressive marketing. Researchers believe this early exposure may shape lifelong food preferences and behavioural patterns.

The study used a preclinical mouse model and observed that subjects exposed to calorie-dense, nutrient-poor diets during early life continued to display altered eating behaviour even after switching to healthier diets and returning to normal body weight.

Researchers linked these effects to disturbances in the hypothalamus, the part of the brain that regulates hunger, appetite, and energy balance.

The study also explored whether changes in gut bacteria could help reverse some of the damage caused by poor childhood diets. Scientists tested a beneficial probiotic strain known as Bifidobacterium longum APC1472 along with prebiotic fibres such as fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS), commonly found in foods including onions, garlic, asparagus, leeks, and bananas.

According to the findings, both probiotics and prebiotic fibres showed promising results in improving feeding behaviour and supporting healthier gut microbiome activity over time.

Lead researcher Cristina Cuesta-Marti said the findings highlight how important nutrition during childhood can be for long-term brain health and behaviour.

Researchers noted that while the probiotic strain produced targeted improvements in feeding behaviour, the prebiotic fibre combination triggered broader positive changes across the gut microbiome.

Scientists believe the findings may help develop future dietary interventions aimed at reducing obesity risk and improving long-term metabolic and brain health in children.