Physical inactivity by Canadians is a major factor contributing to obesity, a report finds.

Monday's report by the Canadian Institute for Health Information (CIHI) and the Public Health Agency of Canada defined physical inactivity as getting less than 15 minutes of low-impact activity a day.

"The equivalent of 405,000 cases of male obesity and 646,000 cases of female obesity could be averted if all individuals in the population attained high levels of physical activity, as measured in this study," Jeremy Veillard, vice-president of research and analysis at CIHI and his co-authors concluded.

Obesity in adults and children

More than one in every four Canadian adults and almost one in 11 children are obese, with a body mass index of more than 30.

Source: CIHI

The OECD also suggested that besides an obesity epidemic, there is also "a less visible, but no less important, epidemic of 'lack of cardio-respiratory fitness.'"

But the ability to be more physically active is influenced by interconnected factors such geography and socio-economic status.

Obesity rates vary with geography

Adult obesity rates for example varied from lows of 5.3 per cent in Richmond, B.C., to highs of 32.1 per cent in Kings County, P.E.I. and 35.9 per cent in the Mamawetan/Keewatin/Athabasca region of Saskatchewan.

In Halifax, 11 per cent of the wealthiest residents were obese compared with nearly 26 per cent in the poorest areas.

Steps to fight obesity

A U.S. review pointed to promising approaches to fighting obesity including:

  • Point-of-decision prompts such as signs encouraging the use of stairs.
  • More frequent and longer physical education classes, and more training for teachers.
  • Comprehensive worksite programs that include counselling, education, incentives and access to supportive facilities such as locker-rooms, showers and gyms.
  • Point-of-purchase strategies, such as menu and shelf labelling, to increase the purchase and consumption of healthier foods.

In contrast, obesity rates were nearly the same between the richest and poorest areas of Vancouver and Oshawa, Ont.

The regional differences could also be related to population differences, researchers said.

Among off-reserve aboriginal adults, nearly 26 per cent self-reported as obese compared with 17 per cent among non-aboriginal adults in 2008, according to Statistics Canada.

Drinking too much alcohol was associated with 190,000 cases of being overweight in men, but did not make much of a difference for women. 

On the other hand, women in higher income brackets were significantly less likely to be obese than poorer women — a difference that was not found in men.

After physical activity, diet seemed to make the biggest difference in obesity rates.

"Eliminating the consumption of a poor-quality diet, as measured by low fruit and vegetable consumption, may result in 265,000 fewer men and 97,000 fewer women being obese," the report's authors concluded.