Almost one-third of Canadian kids overweight: study
TORONTO—Almost a third of Canadian children either are overweight or obese, says a report from Statistics Canada that bases its figures on the World Health Organization method of determining ideal weights for youth around the globe.
Using data from the 2009-2011 Canadian Health Measures Survey, yesterday’s report suggested 31.5 percent of those aged five to 17—an estimated 1.6 million young Canadians—are overweight or obese.
The percentage of kids who were overweight—but not obese—was similar across age groups.
But when it came to those deemed obese, more boys than girls fit the WHO definition, with 15.1 percent of boys being obese compared to eight percent of girls.
The gender gap appears to be particularly noticeable in the five-11 age group, with three times more boys considered obese (19.5 percent) than girls (6.3 percent).
The difference appeared less pronounced among those aged 12-17, with 10.7 percent of boys and 9.6 percent of girls considered obese.
It’s not clear why more boys than girls in the younger age group would be obese. Even the report’s authors footnoted the finding “use with caution.”
“It’s a new observation from our perspective, as well,” said Kim Elmslie, director general of the Centre for Chronic Disease Prevention and Control at the Public Health Agency of Canada.
“Hence the footnote around that, and the need for us really to drill down on what that means because we don’t know at this point what that means,” she admitted yesterday from Ottawa.
“So what we really need to do next, and what we will be doing next, is further analysis to understand why are we seeing this difference in the five- to 11-year age group between boys and girls?”
Experts say the proportion of Canadian kids and teens who are overweight or obese has not changed much in the last few years. What has changed is the method for determining if a child or teen is carrying too many pounds and to what extent.
The traditional estimate of overweight and obese youth—26 percent—primarily has been determined from International Obesity Task Force (IOTF) criteria, based on body mass index (BMI) measurements.
The new report uses WHO’s more recently-implemented weight status charts, also BMI-based, which many medical associations now endorse.
“More people met the threshold based on those new guidelines, so it looks like there’s a jump up in the number of kids who are overweight or obese,” said Dr. Mark Tremblay, director of Healthy Active Living and Obesity Research at Children’s Hospital of Eastern Ontario in Ottawa.
Tremblay, who was not involved in penning the federal report, said it’s unlikely the proportion of overweight and obese kids suddenly has escalated by five or six percentage points.
“No, it’s really just a measurement issue,” he explained.
However, he conceded “we may have been underestimating in the past using the IOTF method how many kids that was.”
Elmslie said the WHO classification system helps public health officials understand the optimal growth trajectory for children and how that should be applied for measuring obesity rates in the population overall.
“The IOTF would result in a rate of one-in-four and WHO would result in a rate of one-in-three children [being overweight or obese],” she said.
“What’s important, however, is that whether it’s one-in-four or one-in-three, it’s too high,” Elmslie stressed.
Tremblay said the rise in childhood obesity is related to a “drifting in lifestyle behaviours” that favour sedentary pastimes such as sitting in front of the computer over physical activities like play and sports.
“And those behaviours at some level represent a misuse or a disuse of our muscles, our heart, our lungs and so on,” he noted.
“And so they atrophy or they degrade or manifest problems at an earlier age.”
He said there has been an acceleration in the age of onset of chronic diseases in young people who are inactive and saddled with extra weight.