Why There's No Such Thing as Healthy Obesity

Clinically obese people are at a much higher risk of cardiovascular disease (CVD) — even if they don’t have prominent health issues like diabetes and high blood pressure, according to the European Association for the Study of Obesity.

The findings add new evidence to the much-debated topic of whether individuals can be identified as “fat but fit”, or having metabolically healthy obesity (MHO) — a condition where a person is clinically obese in terms of their body mass index (BMI) (more than 30 kg/m2), but does not have metabolic complications that usually come with obesity like abnormal blood fats, poor blood sugar control, diabetes, and high blood pressure.

According to the study’s lead author Rishi Calayachetty (pictured), MBBS, PhD, University of Birmingham, United Kingdom, physicians should reconsider describing someone as having MHO in the first place.

“So-called metabolically healthy obesity is not a harmless condition and perhaps it is better not to use this term to describe an obese person, regardless of how many metabolic complications they have,” Calayachetty said. “The priority of health professionals should be to promote and facilitate weight loss among obese persons, regardless of the presence or absence of metabolic abnormalities.”

Calayachetty’s claim is supported by the findings from a 20-year study of 3.5 million individuals — the largest prospective study of the association between MHO and CVD, he said – who did not have a CVD at the study’s inception. Along with a team of researchers, he used linked electronic health records in the Health Improvement Network – a large UK database of general practice records – to assemble the study cohort.

To determine metabolic health, they divided the population into groups according to BMI and the presence or absence of 3 metabolic abnormalities: diabetes, high blood pressure, and abnormal blood fats. To be classified as MHO, participants could not have any of these metabolic abnormalities.

Compared to normal weight individuals with no metabolic abnormalities, study authors found that individuals with MHO had a 50% increased risk of coronary heart disease, a 7% increased risk of cerebrovascular disease and a doubled risk of heart failure after accounting for demographics and smoking behavior.

Against these trends, MHO individuals had a 9% lower risk of peripheral vascular disease (PVD). However, in further analyses that excluded cigarette smokers, MHO individuals had an 11% increased risk of developing PVD.

Obese individuals with metabolic conditions fared even worse. When compared to a normal weight person with zero metabolic abnormalities, an obese person with 3 metabolic abnormalities had a 2.6 times increased risk of coronary heart disease, a 58% increased risk of cerebrovascular disease including stroke, a 3.8 times increase risk of heart failure, and a 2.2. times increased risk of peripheral vascular disease.

Read the full release from the European Association for the Study of Obesity.