Canadian obesity rates have soared over the past 25 years, with nearly one-quarter of all Canadian adults now considered seriously overweight, Statistics Canada said Wednesday.
As well, the government said the same trends are being mirrored in the nation's younger population, where obesity rates have more than doubled over the last quarter century.
By 2004, about 23 per cent of Canadian adults were considered obese, up from 14 per cent in 1978-79.
Similarly, 8 per cent children aged two to 17 fell into the same category. Twenty-five years earlier, just 3 per cent of Canada's children were classified as obese.
"Among young people, the biggest increases in obesity rates over the past 25 years occurred among adolescents aged 12 to 17, where the rate tripled from 3 per cent to 9 per cent," Statscan said.
Overweight and obesity rates were based on body mass index, which is calculated by dividing weight in kilograms by height in metres squared. For adults, a BMI of 25 indicates a person is overweight, while a reading of 30 or more suggests obesity.
For children, the corresponding points vary by age and sex of the child.
Experts in the field said the latest figures should be cause for concern for Canadians.
"Hopefully it is a substantial wake-up call," said Mark Tremblay, a kinesiology professor at the University of Saskatchewan who this week published a new study on fitness levels in Canadian children.
"Just because we've been reporting on this issue for quite some time now, it's not going away and it won't go away until we make some substantial changes to daily behaviours.
"In order to do that on a long-term basis, we're going to make substantial changes to our social and physical infrastructures to accommodate healthy living."
The latest figures, he said, are particularly important in terms of gauging the problem because they are based on direct measurements of respondents' height and weight. Similar studies in the past, he said, had been based on self-reported height and weight measurements from people involved, which left the door open to misrepresentations.
"This may give us a clearer idea of what the true state of the situation is and, of course, it's not good with nearly one quarter of the adults obese and another large chunk are overweight," he said in an interview.
According to Wednesday's report, the most striking upturn in obesity rates among adults was seen in the 25 to 34 and 75 and older age brackets, where the obesity rates doubled to 21 per cent and 24 per cent respectively, Statscan said.
One slight silver lining in the figures, Statscan said, was Canada's ranking compared with its neighbour to the south. In the United States, about 30 per cent of adults are obese.
Most of that difference was linked to differences in obesity rates among women in the two countries.
In Canada, about 23 per cent of Canadian women are obese, compared with 33 per cent of American women.
Still, the government agency said — in this country — obesity rates over the past 25 years were up in almost every age group.
Obesity rates were the lowest — about 11 per cent — for adults of both sexes aged 18 to 24.
"They peaked around 30 per cent among individuals aged 45 to 64," Statscan said. "About one-quarter of seniors were obese."
With few exceptions obesity rates did not vary by province, although men in Newfoundland and Labrador and Manitoba were significantly above the national average in 2004. Women in Newfoundland and Labrador, Nova Scotia and Saskatchewan were also above the national average.
For young people, obesity rates were similar among boys and girls, although trends differed by age groups.
For example, Statscan said, the proportion of children aged two to five who were either overweight or obese remained virtually unchanged over the 25-year period.
The rate of adolescents aged 12 to 17 considered overweight more than doubled, however, to 29 per cent in 2004, from 15 per cent 25 years earlier. The obesity rate for that age group tripled to 9 per cent from 3 per cent.
"Overweight and obesity rates of Canadian and American boys did not differ significantly," Statscan noted. "However, Canadian adolescent girls were significantly less likely than their American counterparts to be obese."
The study also found that, for children aged six to 17, the likelihood of being overweight or obese increased alongside the amount of time spent watching TV, playing video games or using the computer.
Not surprisingly, Wednesday's study also cited diet and exercise as factors in the likelihood of a Canadian becoming obese.
Adult men and women who ate fruit and vegetables less than three times a day were more likely to be obese than those who consumed those foods five or more times each day, the study said.
Similarly, people who spent their down time in sedentary pursuits were also more likely than those who were physically active to be obese.
"For example, 27 per cent of sedentary men were obese, compared with 20 per cent of active men," Statscan said.
"Among women, obesity rates were high not only for those who were sedentary, but also for those who were moderately active."
Income, education and marital status also factored into the equation.
Statscan said men living in higher income households had a higher chance of becoming obese. Women from middle-income households, Statscan said, also had higher levels of obesity.
