Is ‘healthy obesity’ real? More research is needed
In a commentary published in Annals of Human Biology, William Johnson, School of Sport, Exercise, and Health Sciences at Loughborough University, calls for an end to the term “healthy obesity,” due to it being misleading and flawed.
In a commentary published in Annals of Human Biology, William Johnson, School of Sport, Exercise, and Health Sciences at Loughborough University, calls for an end to the term “healthy obesity,” due to it being misleading and flawed. “The notion that it is possible to be obese yet have no cardio-metabolic complications (e.g., dyslipidaemia and hyperinsulinemia) is attractive to those of us whose body mass index (BMI) has crossed the threshold of 30 kg/m2,” writes Johnson. “However, since the first reports of so-called ‘metabolically healthy obesity’ in the 1980s, numerous studies have shown that such individuals 1) can be rare, depending on the population and diagnostic criteria; 2) transition to being unhealthy more frequently than their non-obese counterparts; and 3) have increased risk of various noncommunicable diseases (e.g., type 2 diabetes and chronic kidney disease) and higher mortality compared to healthy normal-weight individuals.”
Johnson goes on to state that the focus should instead be on conducting more in-depth research to understand causes and consequences of varying health among people with the same BMI. Such research would explain why one person has a disease or dies, while another with the same BMI (or waist circumference) is fine.
“It is undeniable that obesity is bad for health, but there are clearly differences between individuals in the extent to which it is bad,” writes Johnson. “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.”
He explains that while epidemiology has revealed many of the life course processes and exposures that lead to a given disease, we know relatively little about the things that occur across someone’s life that lead to them having a heart attack, for example, while their friend with the same BMI is fine. “Existing birth cohort studies have the data necessary to improve knowledge on this topic,” suggests Johnson.
With obesity at epidemic levels worldwide, Johnson concludes that such research could inform the development of more stratified disease prevention and intervention efforts targeted at individuals who have the highest risk.