Could the food we eat affect not just our waistlines, but our minds? A new study suggests that obesity — especially when triggered by a high-fat diet — may be connected to changes in brain function, mood and gut health.
Researchers at Georgia State University found that mice fed a high-fat diet developed more body fat and exhibited signs of anxiety-like behavior compared to lean mice. These changes were accompanied by altered brain signaling in the hypothalamus and distinct differences in gut bacteria.
“Our findings suggest that obesity can lead to anxiety-like behavior, possibly due to changes in both brain function and gut health,” said Dr. Desiree Wanders, the study’s lead author and chair of nutrition at Georgia State.
The study followed 32 male mice from adolescence through early adulthood. Half were given a standard low-fat diet, while the others consumed a high-fat diet for 15 weeks. At the end of the trial, the high-fat diet group showed more defensive freezing behaviors, a common marker of anxiety in mice, and signs of inflammation in brain regions involved in metabolism and cognition.
Importantly, the researchers also found that the gut microbiomes of the obese mice were significantly different, echoing growing evidence that gut bacteria may influence not only digestion, but mental health and cognitive performance.
While the study was conducted in mice and has not yet been peer-reviewed, it adds to the growing body of research connecting the gut, the brain and the foods we eat.
“These findings could have important implications for both public health and personal decisions,” Wanders said, adding that the study highlights how diet may influence both mental and physical health.
More research is needed to confirm whether the same gut-brain pathways function similarly in humans, but the authors hope this work leads to a better understanding of how nutrition affects the whole body, including the brain.
This research was supported by Georgia State University’s Brains & Behavior Seed Grant.