The idea that it might be possible to be overweight or obese but not at increased risk of heart disease, also known as the obesity paradox, has been challenged by a study published today in the European Heart Journal.
This recent research shows that the risk of heart and blood vessel problems, such as strokes and heart attacks, increases as the BMI rises beyond 22-23kg/m2. The risk also enhances steadily the more an overweight person carries around their waist, thus questioning the obesity paradox.
The study from the University of Glasgow, UK, comprised 296,535 healthy adults of white European descent taking part in the UK Biobank study.
Who’s least at risk of cardiovascular disease?
The research team, led by Dr Stamatina Iliodromiti, a clinical lecturer in obstetrics and gynaecology and MRC fellow, found that people with a BMI between 22-23kg/m2 had the lowest risk of cardiovascular disease (CVD).
As the BMI increased above 22kg/m2, the risk of CVD increased by 13% for every 5.2kg/m2 increase in women and 4.3kg/m2 in men.
For men with an 83cm waist circumference and women with 74cm, the risk of CVD increased by 10% and 16%, respectively.
There were similar increases in CVD risk when researchers looked at waist-to-hip and waist-to-height ratios, as well as percentage of body fat mass.
What is the obesity paradox?
Being overweight or obese is commonly known to increase a person’s risk of CVD, as well as other diseases like cancer; however, other studies have suggested that, particularly in the elderly, being overweight or obese might not influence deaths from CVD or other causes.
In some cases, it is seen as being protective, especially if people maintain a reasonable level of fitness, which is known as the obesity paradox.
Challenging ‘protective’ effect of fat
Iliodromiti said: “Any public misconception of a potential ‘protective’ effect of fat on heart and stroke risks should be challenged.
“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 22-23kg/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.”