Even normal-weight people with belly fat and heart disease have a high risk of death compared to folks whose fat is concentrated elsewhere, a large study reports.
A ‘beer belly’ or ‘muffin top’ is as significant a risk factor as smoking a pack of cigarettes a day or having very high blood cholesterol. And the risk is greater for men.
Noting that spare tyre is even more significant than the overall body mass index (BMI, a ratio of weight to height) in predicting risk of death, the findings discount a puzzling theory known as the obesity paradox. Earlier studies have linked a higher BMI and coronary artery disease with better survival chances than normal-weight people.
The researchers suspected that the obesity paradox was happening because BMI is not a good measure of body fatness and gives no insight into the distribution of fat. BMI is just a measure of weight in proportion to height. What seems to be more important is how the fat is distributed on the body. A BMI of between 18.5 and 25 is considered normal; between 25 and 29.9 is overweight; and a BMI of 30 or more is obese.
Researchers from America looked at data from five studies conducted around the world, involving almost 16,000 people with coronary artery disease. The risk of death was nearly doubled for people with coronary artery disease and central obesity, which was determined by waist circumference and waist-to-hip ratio, it was found. What exactly is the difference between belly fat and thigh fat, for instance? Visceral (belly) fat has been found to be more metabolically active. It produces more changes in cholesterol, blood pressure and blood sugar. However, people who have fat mostly in other locations in the body, specifically the legs and buttocks, don’t show this high risk.
Doctors need to look beyond BMI in assessing patients’ health risks and advise those with a large waist or a high waist-to-hip ratio to lose weight, even if they have normal BMIs, the researchers emphasised. All it takes is a tape measure and one minute of a physician’s time to measure the perimeter of a patient’s waist and hip.
Ref: Journal of the American College of Cardiology/NDTV Doctor