If you have 'spare tires' - hidden fat in the abdomen - as well as 'love handles' or visible flab, then you need to be careful as it may worsen heart disease risk factors, according to a new study.
The study by US National Heart Lung and Blood Institute also found that the density of the stomach fat is just as important as how much fat you have.
In general, the higher the fat content, the lower the attenuation, or fat density. These adverse changes in cardiovascular risk were evident over a relatively short period of time and persisted even after accounting for changes in body mass index (BMI) and waist circumference, two commonly used methods to estimate whether someone is a healthy weight or not.
Previous studies showed that people who carry excess abdominal fat around midsection or so-called 'spare tire', tend to face higher risks of heart disease compared to people who have fat elsewhere.
"We show that an increase in the amount of stomach fat and a lower density fat is associated with worse heart disease risk factors, even after accounting for how much weight was gained," said Caroline Fox, who was at the US National Heart Lung and Blood Institute during the research.
"Measuring fat density is a new measure that we are still working to understand and warrants further investigation. We used it as an indirect measure of fat quality and found that lower numbers were linked to greater heart disease risk," she said. Researchers sought to determine whether there was a link between anatomical changes in belly fat - both its volume and density - and changes in a broad array of cardiovascular disease risk factors during the average six-year study period.
They reviewed CT scans to assess how much abdominal fat had accumulated, its location and its density in 1,106 participants. Average age of participants was 45 years and 44 per cent were women. Both subcutaneous adipose fat, the fat just under the skin, which is often visible "flab" or love handles, and visceral adipose fat, the fat inside the abdominal cavity, were measured.
Over the six-year follow-up period, participants had a 22 per cent increase in fat just under the skin and a 45 per cent increase in fat inside the abdominal cavity on average. Increases in the amount of fat and decreases in fat density were correlated with adverse changes in heart disease risk.
Each additional pound of fat from baseline to follow up was associated with new onset high blood pressure, high triglycerides and metabolic syndrome. Even though increases in both types of fat were linked to new and worsening cardiovascular disease risk factors, the relationship was even more pronounced for fat inside the abdominal cavity compared to fat just under the skin.
The study appears in the Journal of the American College of Cardiology.
(With agency input)