Why your waistline is a clue to heart disease

A bulging belly is a better indicator of heart disease than overall body mass, according to scientists.
It has long been known that the more overweight a person is, the higher the risk of having a heart attack.

"We've learned that it's not how fat you are that determines your risk to obesity, but where the excess fat
is located."

Traditionally this risk is measured using the body mass index, which involves dividing weight by height.

But research shows that it is not how fat you are that matters - it's where the fat is.

In the first large-scale study of its kind, Canadian scientists analysed the waist sizes of 168,000 men
and women worldwide.

They found that in men, the risk of heart disease increased by between 21 and 40 per cent for every 5 in
(14cm) extra they put on their waist size.

For women, the same increase in heart disease risk occurred for every 5 in (14.9cm) growth in waistline.

The risk was found to be the same across the populations of the 63 countries studied, despite the wide
variance in waist sizes.

According to researchers, the body mass index does not take into account the distribution of fat on the body.

Danger of fat around the middle

Excess fat around the middle, they say, is more harmful than weight gain on the legs and hips.

This is because fat cells carried-around the stomach are the most dangerous of all, pumping out chemicals
that can damage the insulin system.

Abnormal levels of these toxins can lead to high blood sugar and unhealthy cholesterol levels, increasing
the risk of heat disease and diabetes.

Dr Jean-Pierre Despres, the director of cardiology research at University Laval in Quebec, said: "Your risk
of having a heart attack has nothing to do with your body mass index.

"After 20 years of research we've learned that it's not how fat you are that determines your risk to obesity,
but where the excess fat is located."

He added: "You could be classed as normal weight but if shape - will be at a lesser risk. Dr Despres added:

"This is the first time a study of this magnitude has been conducted worldwide in a primary care population.

"The importance and the clinical significance of these results will stimulate additional studies that will
aid us in identifying patients most at risk."

The Body Mass Index (BMI) is calculated by dividing the person's weight in kilograms by the square of their
height in metres.

A BMI of between 25 and 30 is classed as "overweight", while more than 30 is defined as being obese. The
ideal body mass index is between 18.5 and 24.9.