November 26, 2025, 11:53 am | Read time: 5 minutes

Buttocks Shape Instead of Size Is a Potential Diabetes and Metabolic Early Indicator

Changes in the shape of the buttocks—not its size—could be “early structural markers of metabolic decline,” according to new data, as study author Marjola Thanaj explained to the U.S. news magazine Newsweek.¹ She found that in women with type 2 diabetes, the largest and strongest gluteal muscle—the gluteus maximus—is enlarged. Men, on the other hand, tend to show muscle atrophy there. The gluteus maximus is one of three gluteal muscles and is primarily responsible for the shape of the buttocks.

Thanaj, who researches age- and disease-related changes in body composition through medical image analysis at the University of Westminster, analyzed 61,290 MRI scans of gluteal muscles from the UK Biobank, a vast collection of biological, health, and lifestyle data from volunteers. From each MRI, the researchers created a high-resolution, three-dimensional anatomical model of the buttocks, revealing the smallest shape deviations of the gluteus maximus. Traditional muscle volume or fat content measurements, on which previous studies are based, cannot do this.

The researchers analyzed gender-specific differences in the structure of the gluteus maximus in men and women with type 2 diabetes or frailty.

Also interesting: Possible Symptoms of Type 2 Diabetes Mellitus Overview

Small Dents in the Large Buttocks Muscle in Men with Diabetes

The results highlight specific muscle changes in diabetes that, according to the study’s lead author, have not been previously demonstrated. The researchers closely examined areas on the 3D images where the muscle had sunken inward or bulged outward. Thanaj and her team found that men with type 2 diabetes showed small dents or indentations in the buttocks muscle. This means the gluteus maximus deteriorates early in certain areas, becoming thinner and weaker (atrophy).

Bulges in the Buttocks Muscle in Women with Diabetes

Women with diabetes mellitus, on the other hand, showed bumps or bulges in the buttocks muscle on the 3D images. In these areas, fat accumulates in the muscle or between the fibers, making the muscle appear larger but not stronger.

In short: In women, fat tends to accumulate in the buttocks muscle under diabetes, while in men, this muscle loses mass in clearly defined areas. Of course, training and exercise can also lead to more pronounced buttocks muscles, and it is well-documented that age is a factor in muscle decline.² Such factors, as well as others—medical history, disease biomarkers, lifestyle—were naturally considered in the study.

Buttocks Muscle Shape in “Frail” Women and Men

In men considered “frail,” a general muscle reduction in the gluteus maximus was visible. In women, the change was limited to smaller areas. Again, a clear difference between men and women is evident. More details of the analysis will be presented next week in Chicago, where the annual congress of the Radiological Society of North America will take place from Nov. 30 to Dec. 4, 2025.³

More on the topic

Workout Study Hip Thrust or Squat: Which Is Better for a Toned Butt?

Chronic Metabolic Disease Symptoms Indicating Type 1 Diabetes

Knowledge of Buttocks Shape Could Help Identify People with Metabolic Disorders Earlier

“Our work suggests that changes in the shape of the gluteus maximus can serve as early structural markers for metabolic decline. Features like focal thinning or bulging—often associated with fat deposits—seem to reflect early structural changes in the muscle,” said study author Marjola Thanaj to Newsweek. Focal thinning or bulging refers to a thinning or decrease in the thickness of tissue in a limited, specific area.

From her perspective, more research is now needed—but the results suggest that “the three-dimensional muscle shape could potentially help identify individuals showing early signs of metabolic disorder.” Thanaj explained that clinically, this opens the possibility of observing muscle remodeling over time. This could allow therapists to determine whether an intervention improves the structural health of the muscle and not just its size or overall fat content.

According to Thanaj, people with diabetes often suffer from musculoskeletal problems that limit their mobility and worsen their existing health issues. “Our results highlight specific muscle changes in diabetes that have not been previously demonstrated. They help us better understand musculoskeletal problems in diabetes and potentially optimize physiotherapy treatment programs,” the bioengineering expert is further quoted.

Observational Study – No Causality

Important: We are dealing with an observational study that identifies correlations—but does not prove causality. Whether the muscle changes are actually the cause of later health problems—or rather a consequence—must be clarified in further studies. The data comes exclusively from the UK Biobank, whose participants have certain demographic characteristics (e.g., tend to be healthier than the average population). Therefore, the transferability to other population groups is limited.

Conclusion

The shape of the gluteal muscles could be a new early marker for metabolic risks. 3D models reveal how differently men and women react to the same disease. This represents a significant scientific gain in knowledge.