Metabolically Healthy Obesity and the Risk of Type 2 Diabetes

The term "metabolically healthy obesity" is generally thought to describe excess weight in individuals who don't have any weight-relatable medical conditions. When discussing whether or not these individuals should be counselled to lose weight many point to their potential risk of developing weight-relatable conditions as a reason to do so, and truly, that makes good sense, though looking at the data from my friend and colleague Arya Sharma, it would appear that truly metabolically healthy obesity carries virtually no excess mortality risk - at least not over the 16 years of NHANES data they studied. In Arya's work (graph from same up above) those individuals who are at no risk are staged as EOSS zero - which means that they truly had no discernible weight relatable issues whatsoever - they indeed had metabolically healthy obesity.

So how then to explain the outcomes from a paper published yesterday in Obesity Reviews? The paper, Metabolically healthy obesity and risk of incident type 2 diabetes: a meta-analysis of prospective cohort studies, was a meta-analysis using data from the English Longitudinal Study of Aging and it concluded that those with what they defined as "metabolically healthy obesity" had a 4 fold higher risk of developing type 2 diabetes over a 6 year period than individuals with "metabolically healthy normal weight". The authors then conclude,

"Prospective evidence does not indicate that healthy obesity is a harmless condition."

But before you agree with them there's something important you need to know. Whereas Arya (rightly as far as I'm concerned) defines metabolically healthy obesity (EOSS 0) as an individual who has ZERO weight-relatable conditions, the authors here considered a person to have "metabolically healthy obesity" even if they had one of the following issues: hypertension, impaired glycaemic control, systemic inflammation, adverse high-density lipoprotein cholesterol or adverse triglycerides.

Rather disingenuous don't you think, to describe the increased relative risk of developing type 2 diabetes in individuals who are most assuredly not metabolically healthy as purely consequent to their weight?

Regardless of your weight, if you have hypertension, impaired glycaemic control, systemic inflammation, adverse high-density lipoprotein cholesterol or adverse triglycerides then you are not metabolically healthy, and studies that explicitly suggest otherwise aren't doing anyone any favours, nor answering any questions about risks in those with truly metabolically healthy obesity.