A new study has found that people with greater muscle mass and less deep abdominal fat tend to have brains that appear biologically younger.

The Link Between Muscle Mass, Visceral Fat, and Brain Age

Participants with more developed muscles and a lower ratio of visceral fat to muscle showed signs of a younger biological brain age. These findings were presented by researchers at the annual meeting of the Radiological Society of North America (RSNA). Visceral fat refers to the fat tissue that accumulates deep within the abdominal cavity, surrounding vital organs.

Why This Matters

A healthier body with more muscle and less hidden belly fat is likely associated with a younger and healthier brain. Good brain health, in turn, reduces the risk of diseases such as Alzheimer’s. Brain age is determined by its structure as seen on MRI scans and reflects how biologically old the brain appears. Whole-body MRI allows for tracking muscle mass, which serves as a marker for assessing frailty risk and overall health. Evaluating brain age through structural imaging also helps identify risk factors for neurodegenerative diseases, including muscle loss.

How the Study Was Conducted

The study involved 1,164 healthy adults (52% women) across four research centers, where participants underwent whole-body MRI scans. The average age of participants was 55 years. Imaging included T1-weighted MRI slices, which clearly distinguish muscle, fat, and brain tissue. Using an artificial intelligence algorithm, researchers measured total normalized muscle volume, visceral fat (hidden belly fat), subcutaneous fat, and predicted brain age.

Main Findings

The data showed that people with a higher ratio of visceral fat to muscle had an older predicted brain age. Subcutaneous fat did not show a significant association with biological brain aging. Participants with more muscle mass had younger-appearing brains, while those with more hidden belly fat relative to muscle had older-looking brains. Overall, greater muscle mass and a lower visceral fat-to-muscle ratio were linked to a younger brain.

Practical Implications

The study highlights that increasing muscle mass and reducing visceral fat are realistic and achievable goals. Whole-body MRI and AI-based brain age assessment could become important tools for programs aimed at reducing visceral fat while maintaining or increasing muscle mass.

Impact on Health and Therapeutic Perspectives

The results confirm a strong connection between physical and brain health. The study supports the hypothesis that body composition biomarkers are closely linked to brain condition, laying the groundwork for including these indicators in future clinical trials of various metabolic interventions and treatment methods.

Widely used weight-loss medications, such as GLP-1 receptor agonists (including Ozempic), are effective at reducing fat mass but may also contribute to muscle loss. The findings from this study could help guide the development of new therapies focused on reducing visceral fat while preserving muscle mass.

Conclusion

Reducing fat—especially visceral fat—while maintaining muscle volume has the most beneficial effect on brain aging and health. These results may encourage further research that quantitatively assesses MRI measurements of fat, muscle, and brain age to determine optimal GLP-1 treatment regimens and achieve the best outcomes for both body and brain.