The concept – which relates to people with high BMI but no signs of hypertension, diabetes, or other complications – is misleading, according to Dr Will Johnson, a lecturer in human biology and epidemiology.
He said more attention needed to be paid to understanding the levels, causes, and consequences of differences in health among people with the same BMI – not fixating on misleading terminology.
“The point I am making is that the concept of ‘healthy obesity’ is inherently flawed,” said Dr Johnson.
“This group is actually less healthy, on average, than healthy ‘normal weight’ individuals.
“However, academic studies tend to ignore this, and as a result find obvious results – for example, ‘healthy obese individuals have greater mortality risk than healthy normal weight individuals’.
“Everyone knows the concept of healthy obesity is imperfect, but the same old type of papers keep being published.”
Dr Johnson has published his commentary in the journal Annals of Human Biology.
In it, he said:
“… the very construct of healthy obesity has led to a plethora of epidemiological research and debate on whether or not the phenomenon truly exists, instead of asking questions that accept, exploit, and investigate heterogeneity among people with the same BMI.
“When viewed this way, there are many novel and important research questions that human biologists might see as being better aligned with their field.
“In particular, we know very little about the biological processes & mechanisms (e.g., growth and development patterns) and modifiable lifestyle factors (e.g., physical activity and diet), operating across the life course, that lead to some people developing a disease or dying while other people with the same BMI do not.”
Dr Johnson acknowledged that the concept of healthy obesity is sometimes clinically motivated and allows doctors to separate the growing population of obese adults into those who most urgently require treatment and those who do not.
However, the term is still problematic and crude and should be dropped in order to focus on understanding more about obesity.
Dr Johnson said: “Such research would help develop targeted prevention programmes, in line with various precision or stratified medicine initiatives, such as that of the UK Medical Research Council.
“It is undeniable that obesity is bad for health, but there are clearly differences between individuals in the extent to which it is bad.
“While the concept of healthy obesity is crude and problematic and may best be laid to rest, there is great opportunity for human biological investigation of the levels, causes and consequences of heterogeneity in health among people with the same BMI.”