If you thought it might be possible to be overweight or obese but not at increased risk of heart disease, think again! A new study of nearly 300,000 people has found that unhealthy weight gain can raise risk of heart attacks, strokes and high blood pressure.

The risk of heart and blood vessel problems increases as body mass index (BMI) increases beyond 22-23 kg per square metre, said the study published in the European Heart Journal.

Furthermore, the findings showed that the risk also increases steadily the more fat a person carries around their waist.

“By maintaining a healthy BMI of around 22-23 kg per square metre, healthy people can minimise their risk of developing or dying from heart disease,” said lead researcher Stamatina Iliodromiti from University of Glasgow in Britain.

Although it is already known that being overweight or obese increases a person’s risk of cardiovascular disease (CVD), as well as other diseases such as cancer, there have also been studies that have suggested otherwise.

These studies have cliamed that, particularly in the elderly, being overweight or even obese might not have any effect on deaths from CVD or other causes, and may even be protective, especially if people maintain a reasonable level of fitness.

This is known as the “obesity paradox”.

However, the new study refute these previous, conflicting findings.

“Any public misconception of a potential ‘protective’ effect of fat on heart and stroke risks should be challenged,” Iliodromiti said.

The researchers found that as BMI increased above 22 kg per square metre, the risk of CVD increased by 13 per cent for every 5.2 kg per square metre increase in women and 4.3 kg per square metre in men.

“This is the largest study that provides evidence against the obesity paradox in healthy people,” Iliodromiti said.

“It is possible that the story may be different for those with pre-existing disease because there is evidence that in cancer patients, for instance, being slightly overweight is associated with lower risk, especially as cancer and its treatments can lead to unhealthy weight loss,” she added.