New research in mice reveals a convincing link between obesity and anxiety, potentially motivated by changes in brain function and intestinal bacteria.
Young mice have fueled a regime rich in fat developed by obesity, have shown anxious behavior and had distinct cerebral and microbiome models compared to their lean counterparts. These results suggest that the intestinal brain axis could play a key role in obesity mental health results.
Obesity and anxiety: an intestinal brain connection?
Obesity and anxiety increase quickly, especially among young Americans. Now new research suggests that these two conditions can be more closely linked than we thought. In a study using mice, scientists have found that a diet rich in fats led not only to weight gain, but also to anxious behavior, changes in brain activity and changes in intestinal bacteria that could affect the functioning of the brain.
“Several studies have underlined a link between obesity and anxiety, although it is still not clear if obesity directly provokes anxiety or if the association is influenced by societal pressures,” said Desiree Wanders, PHD, associate professor and president of Nutrition at Georgia State University. “Our results suggest that obesity can lead to anxious behavior, perhaps due to changes in brain function and intestinal health.”
Wanders shared the results of nutrition 2025, the annual flagship meeting of the American Society for Nutrition held in Orlando, Florida.
Proxide the effects of the brain and behavior
Although the connection of obesity with diseases such as diabetes and heart problems is well known, its effects on brain health are less understood. To explore the link between body weight, brain function and anxiety, researchers used a mouse model that reflects many of the same metabolic problems observed in humans.
The study followed 32 young male mice of adolescence at the beginning of adulthood. Half was fed by a low fat diet, while the other half consumed a diet rich in fat. At the end of the study, the group rich in fat had gained much more weight and body fat than the lean group.
Anxiety behaviors and brain signal disruption
In behavioral tests, the researchers found that obese mice had more anxious behavior, such as freezing (defensive behavior present in response to a perceived threat), compared to lean mice. These mice have also shown different signaling models in the hypothalamus, a region of the brain involved in the regulation of metabolism, which could contribute to cognitive impairments.
In addition, researchers observed distinct differences in the composition of intestinal bacteria in obese mice compared to lean mice. These results align with an increasing set of evidence pointing to the role of the intestinal microbiome in the regulation of behavior.
Significant human ideas mice
While recognizing that research in mice does not always translate directly into humans, Wander has said that the results provide new information that highlights the importance of targeting several systems in understanding and potentially processing cognitive impairments related to obesity.
“These results may have important implications for public health and personal decisions,” Wander said. “The study highlights the potential impact of obesity on mental health, especially in terms of anxiety. By understanding the links between food, brain health and intestinal microbiota, this research can help guide public health initiatives which focus on prevention of obesity and early intervention, especially in children and adolescents. ”
The errors have also noted that the carefully controlled conditions used in the study lend the rigor and credibility to the results, but have added that the real world is much more complex.
Complex influences beyond the only diet
“Although our results suggest that the diet plays an important role in physical and mental health, it is important to remember that the diet is just a piece of the puzzle,” said Wanders. “Environmental factors, genetics, lifestyle choices and socioeconomic status also contribute to the risk of obesity and its associated health results.
Then, the researchers hope to further explore the mechanisms by which obesity induced by the diet affects the brain and behavior by deepening changes in the intestinal microbiome and by expanding their study to include female mice and different age groups. Errors have added that it would be useful to determine whether weight loss interventions could reverse the impacts.
Meeting: nutrition 2025
Never miss a breakthrough: Join the Scitechdaily newsletter.
