Size DOESN’T matter! The shape of your bottom can predict if you will develop diabetes

A new study has found that the size and shape of your bottom can predict if you will develop diabetes.

It’s well known that being overweight or obese is associated with a host of health problems, whilst muscle loss is associated with aging.

But according to new research to be presented at the annual meeting of the Radiological Society of North America next week, the shape of the muscle in our rear ends—anatomically known as the gluteus maximus—changes not only with age, but conditions like type 2 diabetes and osteoporosis.

And these changes differ between men and women. 

Researchers at the University of Westminster used 3D magnetic resonance imaging (MRI) to reveal specific patterns in the glutes that were associated with type 2 diabetes, suggesting that it’s the shape, not the size, that matters when it comes to underlying metabolic diseases. 

Dr Marjola Thanaj, an expert in bioengineering and study lead author, said: ‘Unlike past studies that mainly looked at muscle size or fat, we used 3D shape mapping to pinpoint exactly where the muscle changes, giving a much more detailed picture.’ 

Analysing data from nearly 61,300 MRI exams from the UK Biobank database, the team found that men with type 2 diabetes tend to experience muscle shrinkage, while women showed enlarged muscle, likely due to a build-up of fat within the glutes. 

In addition to the scans, researchers also considered participants’ physical measurements, demographic, medical history, disease biomarkers and lifestyle. 

‘People with higher fitness, as measured by vigorous physical activity and hand grip strength, had a greater gluteus maximus shape, while aging, frailty and long sitting times were linked to muscle thinning,’ Dr Thanaj explained.

Men considered ‘frail’ also had more general shrinkage across the muscle, whereas the effect of aging was limited to smaller areas in women, suggesting that men and women have very different biological responses to the same disease. 

The gluteus maximus is one of the largest muscles in the human body, and it plays a key role in metabolic health—a marker of how well the body is processing fats and sugars and responding to insulin. 

In its simplest terms, diabetes occurs when the level of sugar in the blood becomes too high as a result of problems with the hormone insulin. 

People with type 2 diabetes don’t produce enough insulin, or the insulin they do produce doesn’t work properly—known as insulin resistance. 

This causes the level of glucose in the blood to become too high, increasing the risk of other long-term health problems such as heart disease, stroke, blindness, kidney problems and gum disease. 

But this happens gradually over a number of years, as blood glucose levels begin to climb, with many not realising they’re at risk of developing the condition as prediabetes tends to be symptomless. 

Whilst no one thing causes the condition, genetics, age, body weight and where the body stores fat are all thought to play a role. 

 In the current study, the team concluded that shape changes in the muscle could be an early warning sign of type 2 diabetes, reflecting sex-specific differences in response to insulin tolerance.

This finding is in line with the long-proven idea that it is possible not to be visibly overweight, but to still be at risk of the disease—because even someone with a ‘healthy’ body mass index (BMI) may have gone beyond their own fat threshold. 

Therefore, health professionals advise looking out for any changes in waist size, and now glute shape, which could indicate poor metabolic health. 

According to Diabetes UK, one if five or around 12 million people, in the UK are now living with prediabetes and diabetes. Figures estimate that 4.6million people now have a diagnosis of type 2 diabetes.