Early Exposure to Junk Food Has Brain-Altering Effects

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WWith the abundance of sugary cereals, sugary snacks, and fast foods available, getting kids to eat healthily is a constant struggle for parents. Now, new research published in Natural communications suggests that junk food diets can have a lasting impact on our eating behaviors later in life, and even our brains.

Researchers at University College Cork in Ireland raised mice on a high-fat, high-sugar diet and monitored their eating behaviors as they grew into adulthood. Although the mice’s weight normalized once they were switched to a control diet as adults, they still ate more than the control mice and opted for the energy-dense, nutrient-poor foods they had been raised on when given a choice. Researchers have linked these behaviors to changes in the hypothalamus, which plays a key role in regulating appetite.

“Our results show that what we eat early in life really matters.” explained Cristina Cuesta-Martí, co-author of the study, in a press release. “Early dietary exposure can leave hidden long-term effects on eating behavior that are not immediately visible through weight alone. »

Read more: “How the Western regime derailed our evolution”

Can these behaviors be reversed?

To find out, researchers modified the intestinal microbiome of mice raised on junk food. They introduced probiotic intestinal bacteria Long bifidobacteriaas well as prebiotic fiber, fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS) naturally found in onions, asparagus and bananas.

Using the probiotic infusions, they were able to restore normal eating behaviors, although there were some gender differences in the results. Bacteria normalized food preferences in both male and female mice, while FOS and GOS normalized food preferences only in male mice.

“Our results show that targeting the gut microbiota can mitigate the long-term effects of an unhealthy diet early in life on later eating behavior,” said Harriet Schellekens, co-author of the study. “Supporting the gut microbiota from birth helps maintain healthier eating behaviors later in life. »

Although these results currently only apply to mice, it is best to instill healthy eating behaviors in your children when they are young. Sorry parents.

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Main image: beats1 / Shutterstock

• Jake Currie

  Published on February 27, 2026

  Jake Currie is a writer based in Brooklyn, New York.