Carrying extra weight could raise the risk of a heart attack by more than a quarter, even if patients appear are otherwise healthy, according to UK researchers.
They found being overweight or obese increased the risk of coronary heart disease by up to 28%, compared to having a healthy bodyweight, even if blood pressure, blood glucose and cholesterol levels were all considered healthy.
“Overall, our findings challenge the concept of the ‘healthy obese’”
Previous studies had identified a subset of overweight people who appeared to lack the adverse effects of excess weight, leading them to be labelled “metabolically healthy obese” or “fat but fit”.
But the new study authors said their findings added to growing evidence that the idea of being “fat but fit” was a myth, and that people should aim to maintain a body weight within a healthy range.
Led by researchers at Imperial College London and the University of Cambridge, it showed that excess weight was linked with a higher risk of heart disease, even when patients have a healthy metabolic profile.
The researchers used data from more than half a million people in 10 European countries – taken from the European Prospective Investigation into Cancer and Nutrition (EPIC) – in the largest study of its kind to date.
After a follow-up period of more than 12 years, a total of 7,637 EPIC participants experienced CHD events. The researchers then compared them against more than 10,000 individuals as controls.
Following adjustment for lifestyle factors, the researchers found those classed as unhealthy had more than double the risk of CHD, whether they were normal weight, overweight or obese.
However, their analysis also revealed that within the apparently healthy group there was a significant difference in outcomes for people depending on their weight.
‘Fat but fit’ at increased risk of heart disease, warn researchers
Compared to those at normal weight, people classified as healthy but overweight had an increased CHD risk of 1.26 (26%), while those who were healthy but obese had an increased risk of 1.28 (28%).
Lead author Dr Camille Lassale, formerly of Imperial’s school of public health and now based at University College London, said: “Our findings suggest that if a patient is overweight or obese, all efforts should be made to help them get back to a healthy weight, regardless of other factors.
“Even if their blood pressure, blood sugar and cholesterol appear within the normal range, excess weight is still a risk factor” she said.
Dr Lassale added: “Overall, our findings challenge the concept of the ‘healthy obese’.”
The study, published in the European Heart Journal, was funded by the European Union and supported by the Medical Research Council, the British Heart Foundation and the National Institute for Health Research.