Adiposity, obesity and metabolic health – 'fat but fit'?

Why the concept of metabolically healthy obesity is grabbing headlines

They can’t both be going the right way… Photo by Edurne Tx

Speaking at a recent conference, Professor Matthias Blüher – the Director of the Helmholtz Institute for Metabolic, Obesity and Vascular Research in Germany – said that one-quarter of middle-aged women and 10% of middle-aged men in the UK have metabolically healthy obesity (MHO). 

This was picked up by a number of news outlets, and the story seems to be making the rounds. 

What does MHO mean? Also known as “fat but fit”, MHO is a relatively new term to describe someone who is obese but doesn’t have the health problems that we typically see with obesity, like high blood pressure, high cholesterol and higher rates of diseases like type 2 diabetes. 

Interestingly, Prof. Blüher said that there was quite a bit of variation in the levels of MHO across the world. Globally, it looks like 15-20% of obese people have MHO, and the rate is much higher in women than in men. 

The UK sits roughly on par with other Northern European countries like Sweden, Norway and Germany, with 8% of men and 27% of women aged 40-50 with MHO. 

But these figures are lower in other parts of the world, like Micronesia and Asia; as low as 2-5% in fact. Prof. Blüher puts this down to some populations having better protection from the damaging effects of obesity than others. 

Where you store your fat tissue and how your fat cells behave might shed light on understanding this phenomenon and might actually be a better indicator of health than measures like BMI, Prof. Blüher said. 

BMI categories: not as simple as it seems. Photo by Kilian Seiler

BMI categories: not as simple as it seems. Photo byKilian Seiler

People who have regular-sized fat cells are much less likely to have obesity-related health complications than people with enlarged fat cells and inflammation in their fat tissue.