KEY POINTS:
"Fat and fit" men are likely to have a lower risk of heart disease and diabetes because they're relatively trim around the waist, a new study shows.
The higher a man's cardio-respiratory fitness, the less fat he has in his abdominal cavity, Dr Jean-Pierre Despres of Hopital Laval Research Centre in Quebec and colleagues found.
The relationship held true regardless of body mass index (BMI), a ratio of weight to height typically used to gauge excess weight and obesity.
"This is why it's so, so important for the doctor to measure waist circumference," said Despres, who told Reuters Health he is on a "crusade" to get family doctors to check their patients' waist size and triglyceride levels.
High waist circumference combined with high triglyceride levels signal a substantially increased risk of heart disease and diabetes, he explained.
There is mounting evidence that fit people are at reduced risk of heart disease, even though they may be overweight or even obese based on their BMI, Despres and his team note in the Archives of Internal Medicine.
At the same time, the researcher added, people of normal weight with bulging bellies can be "time bombs" for heart disease.
He and his colleagues hypothesized that fit individuals, regardless of BMI, would have less belly fat.
To investigate, they looked at 169 healthy men, comparing their cardio-respiratory fitness with their amount of belly fat as measured by computed tomography (CT) scanning.
As the researchers suspected, men's belly fat accumulation rose as their cardio-respiratory fitness fell.
The relationship remained even after the researchers considered the effects of BMI and age.
Despres and his team conclude that physical activity should be promoted for everyone, regardless of age, gender or BMI, to trim belly fat and thus reduce heart disease risk.
The researchers are currently conducting a similar study in women, who are somewhat protected against the accumulation of deep abdominal fat until they reach menopause, he added.
People who don't see a change in their BMI after they have been exercising shouldn't be discouraged, Despres said, but should instead check to see if their waists are shrinking.
This will indicate that their efforts are indeed having an effect.
- REUTERS