Fat but Fit – Real or Myth?
The Study:
A study entitled “Separate and combined associations of obesity and metabolic health with coronary heart disease: a pan-European case-cohort analysis” was reported in the 8/14/2017 issue of the European Heart Journal . This study has been widely reported in the news media. They sought to answer the question ” if a person is otherwise metabolically healthy, does being obese or overweight have harmful effects on heart health?”.
A group led by researchers at the Imperial College of London and the University of Cambridge took data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study. This included more than a half million people in 10 European countries.
Definitions:
“Metabolically unhealthy” = a person who has 3 or more of a number of metabolic markers which include:
- High blood pressure
- High blood glucose
- High triglyceride levels
- Low LDL levels
- Waist size greater than 37″ (men), 31″ (women)
Weight status was defined as:
- BMI 18.5-25 = Normal
- BMI 25-30 = Overweight
- BMI 30+ = Obese
They adjusted the results to factor out lifestyle variables such as smoking, diet, exercise and socioeconomic status.
Results:
- Those classified as “unhealthy” had more than double the risk of CHD (Coronary Heart Disease) regardless of their weight status.
- Within the “healthy” group:
- those overweight had a 26% increase risk of CHD
- those obese had a 28% increase risk of CHD.
So, they conclude that being overweight or obese is an independent risk factor for CHD and that “Fat but Fit” is not healthy, even if your “metabolic health” is good.
My Thoughts:
Adult cardiologists regularly use the term “Metabolic Syndrome” to describe the condition that this study refers to as “Metabolically Unhealthy”. It has been clearly documented that if a person fits the criteria for metabolic syndrome, they are at significantly increased risk for health problems, especially CHD.
I see a major problem in the study’s definition of “Healthy” and “Unhealthy”. Clearly anyone with all the criteria for metabolic syndrome is unhealthy for having that cluster of risk factors/problems. However, according to that same definition, anything less than 3 risk factors is classified as “Healthy”. Calling a person, with say, high blood pressure and an elevated blood glucose “Healthy”, is misleading. I think the results need to be broken down fully to analyse each risk factor and their multiple permutations separately. In this way one can measure the risk contribution of each factor separately, and their effect in their possible combinations. The “Healthy” control group should be not those who aren’t classified as having metabolic syndrome, but those individuals who have no risk factors at all, and are of normal weight.
Had they defined the normal group as I suggest above, then the difference between the “Healthy” group as I define it and the “Unheathy” group as they define it would have likely been far greater.
Also, this study is focusing on the effect on CHD. We know being overweight is associated with a long list of problems, which aren’t looked at in this study.
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