Almost a third of Canadians aged five to 17 are overweight or obese, Statistics Canada finds.

The prevalence of overweight and obese Canadian children hasn't increased over the past decade, but the agency said Thursday that it remains a public health concern.

Using World Health Organization standards of measurement, 31.5 per cent of five- to 17-year-olds — an estimated 1.6 million Canadians — were classified as overweight (19.8 per cent) or obese (11.7 per cent) from 2009 to 2011.

Among children aged five to 11, the percentage of obese boys (19.5 per cent) was more than three times that of obese girls (6.3 per cent), the agency said.

"Although these estimates have not changed significantly in recent years, more data points are needed to determine if the pace of increase in prevalence is slowing, as has been observed in some countries," the report concludes.

"Regardless, the estimates remain high and are a public health concern, given the tendency for excess weight in childhood to persist through to adulthood."

'Easy to get calories'

CBC medical contributor Dr. Karl Kabasele said many factors are fuelling child obesity.

"The food industry and the processed foods have kind of created this environment where it's so easy to get calories," said  Kabasele. "Kids are playing video games, watching TV, not getting out and exercising. So all of these factors are kind of conspiring against kids despite our best efforts.

"The medical community has to work hand in hand with parents, with the food industry, with government regulators to figure out the best way to kind of reduce this obesogenic environment that kids are growing up in."

Canada seems to be a country of "chronic pilot studies," so changes are rarely made for long enough to see if they make a difference, said Dr. Marc Tremblay, director of active living and obesity research at the Children's Hospital of Eastern Ontario.

"It's a wake-up call that we need to make some fundamental shifts," Tremblay said. "We need to stop saying 'we can't' because the health of the population is at stake here."

The heights and weights of 2,123 children and teens were taken from the Canadian Health Measures Survey done by Statistics Canada, Health Canada and the Public Health Agency of Canada between August 2009 and December 2011.

With files from CBC's Kelly Crowe