For many people, middle-aged spread is as much a part of getting older as laughter lines, receding hairlines and worsening hangovers. But research suggests that even the smallest of pot bellies may be a serious health risk.

After examining more than 2,700 men and women with an average age of 45, scientists at the University of Texas Southwestern Medical Centre in Dallas found that those with even a little fat around their waists were significantly more vulnerable to heart disease, even if their overall weight was normal.

Their findings, published in the Journal of the American College of Cardiology (JACC), may come as a shock to many who would not consider themselves fat. But they reinforce a growing belief among medical experts that waist-to-hip ratio (WHR) is a more accurate measure of healthy shape than the widely used body mass index (BMI).

BMI, which is calculated by dividing weight in kilograms by height in metres squared, gives an overall indication of heaviness compared with height. But according to BMI measurements, well-toned specimens from Brad Pitt to the rugby star Jonah Lomu would be classed as overweight, and increasing numbers of experts are now questioning BMI’s usefulness.

The new study by James de Lemos and his team adds credibility to the theory that WHR is a more accurate means of measuring heart-disease risk because it identifies potentially dangerous “central obesity” even in those who are not overweight.

The researchers conducted a series of examinations on their participants, ranging from blood sampling to MRI scans. All underwent imaging tests to look for early signs of calcium build-up in the arteries of the heart, which is linked to an increased risk of developing cardiovascular disease later in life.

These deposits are a reflection of atherosclerosis – commonly referred to as “hardening” of the arteries – and can be detected years before a patient suffers chest pain or has a heart attack.

Researchers examined the relationship between body shape and early signs of disease in the arteries. They found that the likelihood of there being calcium deposits in the arteries grew in direct proportion to the increase in waist-to-hip ratio.

A breakdown of the participants into five groups showed that those with the highest WHR were almost twice as likely to have calcium deposits in their coronary arteries as those with the smallest WHR. Even when factors such as blood pressure, diabetes, age, high cholesterol levels and smoking were taken into account, the link remained strong.

Dr de Lemos said: “In our thirties and forties, we often gain three to four inches in the midsection. It’s a day-to-day, meal-to-meal battle, but it’s worth fighting. We don’t have to clean our plates. It’s better to throw food out than add it to our waists. Even a small pot belly puts us at higher risk when compared to a flat tummy.”

June Davison, cardiac nurse at the British Heart Foundation, said: “People who are overweight or obese have an increased risk of developing heart disease. The risks are even higher when fat is mainly concentrated around the abdomen.

“What’s important is that people consider their body shape as well as their weight.”

Explore Health

• Expert Advice

• Health Features

• Mental Health

• Alternative Medicine

• Child Health

• Health Club