Obesity may mess with your mind! Scientists say it could rewire your brain and trigger anxiety

A new study shows obesity may lead to anxiety-like behaviour through changes in brain function and gut microbiota. Diet-induced obesity in mice triggered both physical and mental health issues, especially during adolescence and early adulthood.

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Image Credit: Getty

A new study has found that obesity may contribute to anxiety-like behaviours by disrupting communication between the gut and the brain. The research links diet-induced obesity with changes in brain signalling and gut microbiota that may impair mental health.

"Several studies have pointed to a link between obesity and anxiety, though it is still unclear whether obesity directly causes anxiety or if the association is influenced by societal pressures," said Dr. Desiree Wanders, associate professor and chair of nutrition at Georgia State University. "Our findings suggest that obesity can lead to anxiety-like behaviour, possibly due to changes in both brain function and gut health."

Mouse model used to study obesity's effects on brain and behaviour

To explore the connections between obesity, brain function, and anxiety, researchers used a mouse model that mimics human obesity-related conditions. The study involved 32 male mice, split into two groups. From adolescence to early adulthood, one group received a low-fat diet and the other a high-fat diet.

By the end of the study, mice on the high-fat diet had significantly higher body fat. These obese mice showed more anxiety-like behaviours, such as freezing when threatened, compared to lean mice.

Brain signalling changes seen in obese mice

Researchers discovered altered signalling patterns in the hypothalamus—a brain region that helps regulate metabolism—in obese mice. These changes may be connected to cognitive and emotional impairments often observed in individuals with obesity.

Gut microbiota differences suggest gut-brain link

The study also found significant differences in the gut bacteria of obese mice compared to those on a low-fat diet. These findings support growing evidence that the gut microbiome plays a crucial role in shaping behaviour and brain health.

Implications for public health and mental well-being

Dr. Wanders emphasized the broader implications of the findings: "These results highlight how obesity, particularly in children and adolescents, could affect not just physical health, but mental health too. This could guide future public health strategies focused on early intervention."

Study limitations and future directions

While the study was conducted under controlled lab conditions, Wanders acknowledged the complexity of real-life scenarios. She stressed that obesity and mental health are influenced by many factors such as genetics, environment, lifestyle, and socioeconomic status.

Researchers now plan to further examine the mechanisms linking obesity with brain function. They also hope to include female mice and additional age groups in future studies, and explore whether weight loss can reverse the effects observed.