Three-quarters of the Maltese population may be overweight or obese, but that does not necessarily mean they are unhealthy, according to a study which revealed that over half its overweight and obese participants are in good metabolic health.

This means their glucose, cholesterol and blood pressure parameters are within normal levels, despite a high body mass index. This amounts to 40 per cent of the total population, including those of normal weight, having a clean bill of health.

The researchers, specialised doctors in the field of obesity and diabetes, however, clarified they were not sending out a message that being obese is OK.

The findings did not promote the ‘fat but fit’ theory – a claim that was debunked in a major 2017 UK study showing that, even if metabolically healthy, people with obesity ran an increased risk of heart failure and stroke. 

The local research focused on the prevalence of adult individuals living with obesity, who are metabolically healthy, and that of lean persons, who despite having a normal BMI, were not necessarily better off in terms of metabolic health.

As a result, accumulating data showed that individuals with what has been termed metabolically healthy obese were likely to be at a lower risk of certain complications, such as type 2 diabetes and cardiovascular disease, compared not only to those individuals falling within the obese and unhealthy category, but also compared to the metabolically unhealthy normal weight individuals.

The study, in fact, also showed that one in three Maltese adults are metabolically unhealthy, irrespective of their BMI, and therefore, at a higher risk of disease than the newly discovered ‘obese but healthy’ category. This meant an increased future cardiovascular disease burden within the Maltese population, said lead researcher Rachel Agius, a consultant endocrinologist and diabetologist, with a special interest in obesity medicine.

The study turns some preconceived ideas on their head: having a normal body weight did not necessarily equate to being healthy and at low risk of disease, while conversely, someone living with overweight or obesity did not automatically have abnormal metabolic parameters, Agius explained.

However, referring to the landmark Birmingham University study, she underlined that obesity is a disease and carried health consequences, irrespective of metabolic health. 

“While metabolically healthy obese individuals are still at risk of certain diseases, compared to the gold standard – normal weight and metabolically healthy people – those with a normal weight, who have even just one metabolic problem, such as high fats, can be at higher risk of heart attack than those who are obese but healthy and would need to check their sugars, fats and blood pressure,” Agius reiterated.

The study, carried out together with  Stephen Fava and Nikolai Paul Pace, both professors at the University of Malta, indicated that Maltese with a lower BMI should not take it for granted that they are healthier than their overweight counterparts and are not “absolved” from metabolic abnormalities.

The research worked with a random population sample of middle-aged Maltese Caucasians, around 40 years old, living in an “unhealthy” country. It sampled fewer males than females.

While 70 per cent of the sampled population fell within the obese or overweight BMI categories, it revealed that a “substantial” number – about 56 per cent – were metabolically healthy.

According to the study, the “gold standard” category – metabolically healthy normal weight individuals – made up 27 per cent of the total sample, while 38 per cent were metabolically healthy overweight or obese, whose glucose, cholesterol and blood pressure values were within the normal ranges.

At the other end of the scale were the obese and unhealthy – 22 per cent – which Agius described as a “double whammy”. “They are not just living with the disease of obesity, which in itself also carries risk of several debilitating conditions, but are also unhealthy; like a timebomb, ready for cardiovascular disease,” she said.

“We usually associate obesity with metabolic ill health, but this is not universal. Some people who are living with obesity have a better metabolic profile than their leaner counterparts,” she said.

Other take-home points from the study included the fact that while obesity was typically associated with increased risk for type 2 diabetes, high blood pressure and high cholesterol and, therefore, an impetus for more medical check-ups, individuals who fell within a normal BMI category were not absolved of metabolic ill-health and should also undergo screening tests for metabolic complications, said Agius.

Maltese men metabolically unhealthier than women

The study also found that Maltese men were metabolically unhealthier than women, with almost half of the males sampled (41 per cent) being unhealthy, irrespective of their BMI, while almost three-quarters of women were healthy.

Men were also consistently observed to have less favourable metabolic parameters compared to females even when classified as being metabolically healthy – when their levels of glucose, cholesterol and blood pressure fell within normal reference ranges, Agius said.

When both are given a clean bill of health, women are still healthier than men

She acknowledged that, worldwide, men were inherently more likely to have abnormal metabolic parameters, compared to women, irrespective of their BMI.

“This is known about men, due to their hormonal make-up, but the difference between the sexes had never been exclusively studied in Malta,” she said about the missing data. The study now confirmed this in the Maltese Caucasian population.

“It means that Maltese men should possibly be screened at an even younger age (even younger than 40), be more vigilant with their clinical check-ups and have a lower BMI cut-off point,” Agius pointed out. 

Analysing sex differences further, the study found that females, compared to males, were inherently healthier even when obese – 36.5 per cent as opposed to 25 per cent respectively.

“When both are given a clean bill of health, women are still healthier than men,” she said.

One reason for this is that men have an increased predilection for storing excess calories as “bad” visceral fat around the internal abdominal organs, while females tend to deposit fat in ‘good’ peripheral subcutaneous areas such as the buttocks and thighs.

Whether the fact that a substantial number of individuals living with obesity and overweight, and who are metabolically healthy, translated into lower risks of disease within the Maltese population was not yet known, Agius said.