A new study questions the concept of being ‘healthy at any weight’.

Researchers have been investigating the 'obesity paradox' - the idea that it could be possible to be overweight or obese without an increased risk of heart disease.

A new study from the University of Glasgow finds people who are overweight or obese are likely to have a higher risk of heart and blood vessel problems.

The authors tracked the health of almost 300,000 adults and found they were more likely to have problems such as heart attacks, strokes and high blood pressure if they were overweight or obese, or if they carried more fat around their waists. 

Comparing women and men with waist circumferences of 74 and 83 cm respectively, the cardio-vascular disease risk increased by16 per cent in women and 10 per cent in men for every 12.6 cm and 11.4 cm increase in waist circumference for women and men respectively.

Similar increases in disease risk were seen when the researchers looked at waist-to-hip and waist-to-height ratios and percentage body fat mass – all of which are considered reliable ways to accurately gauge the amount of fat a person carries, also known as adiposity.

Although being overweight or obese increases a person’s risk of cardio-vascular disease, as well as other diseases such as cancer, there have also been studies that have suggested that, particularly in the elderly, being overweight or even obese might not have any effect on deaths from cardio-vascular disease 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 authors of the new study say their results refute these previous, conflicting findings.

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

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

“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.

“By maintaining a healthy BMI of around 22-23 kg/m2, healthy people can minimise their risk of developing or dying from heart disease. In terms of other adiposity measures, the less fat, especially around their abdomen, they have, the lower the risk of future heart disease.”

The researchers recognise that it can be difficult for some people to maintain a low BMI, particularly as they get older.

“We know many cannot get to such low BMIs so the message is, whatever your BMI, especially when in the overweight or obese range, losing a few kilograms or more if possible, will only improve your health,” said co-author Professor Naveed Sattar.

“There are no downsides to losing weight intentionally and the health professions needs to get better at helping people lose weight.”

The study is accessible here.