"Waist circumference has to be considered a vital sign. It's absolutely vital to measure," Jean-Pierre Despr�s, a professor of human nutrition at Laval University in Quebec City and an internationally renowned obesity expert, said in a recent interview.

"It's a vital measure because the abdominally obese are ticking time bombs for heart disease and diabetes."

Dr. Despr�s said a waistline of more than 100 centimetres (40 inches) for a man and 90 centimetres (35 inches) for a woman should be considered a risk factor for these serious conditions.