To put it another way, the study found that obese patients faced an increased risk of heart attack and stroke simply because of the amount of weight they were carrying, as they were determined to be healthy in all other metabolic measures.
Worse still there are no warning signs such as high blood pressure or diabetes.
What lead author Dr. Rishi Caleyachetty and his colleagues discovered was that individuals who had a BMI of at least 30 at the start of the study were 50 percent more likely to contract coronary heart disease than those considered to be at a healthy weight.
There is no evidence to support the idea that it is possible to be healthy yet obese, say scientists, following a study of 3.5 million NHS patients. The data is based on the medical records of 3.5 million people in the United Kingdom between 1995 and 2015.
While most obese people have an increased risk of developing conditions such as heart disease, stroke and type 2 diabetes compared to those of a normal weight, experts had picked up on the fact that some seem to buck that trend and remain healthy.
He added: 'What we have shown in this study of 3.5 million people is that metabolically healthy obese individuals, compared to those of normal weight, are at higher risk of conditions such as heart disease, stroke and heart failure.
They found that while they were "metabolically healthy", they were at a greater risk of developing heart disease, strokes and heart failure than those of a healthy weight.
A team from the Institute of Applied Health Research at the University of Birmingham has now cast doubt on this idea in the biggest study of its kind. The healthy obese also are twice as likely to experience heart failure and have a higher risk of peripheral artery disease. It is generally agreed to be imperfect because athletes and very fit people with dense muscle can have the same BMI as somebody who is obese.
The idea of being fat but fit is officially a myth according to new research coming from experts in Portugal.
These figures held true even when factors such as whether people smoked were taken into account. When their analysis was adjusted to exclude cigarette smokers, MHO people also had an 11 percent increased risk of PVD.
"Metabolically healthy obesity is not a harmless condition, and it would be incorrect to think so".
The British study reverses the assumption that overweight people can be healthy as long as they exercise and eat well. "It's actually better not to use this term as it can create a lot of confusion".
There is no such thing as being fat and fit, experts warned yesterday. Ask any group of rugby forwards who shift their bulk up and down a 100m field for 80 minutes and you'll get a "yes". The new study has debunked the widely health medical belief that some fat people can also stay fit. "Ask scientists stuck in a lab and you might not".