Data Blog

What is obesity and how is it measured?

Obesity is a complex condition in which excess body fat poses a risk to health¹.

Body Mass Index (BMI) is the primary measure used to track obesity in the Canadian population. BMI is a measure of a person’s weight in relation to their height squared².

All estimates are taken from the Canadian Risk Factor Atlas (CRFA) using pooled data from the Canadian Community Health Survey, 2015-2018.

• About 1 in 4 Canadian adults (26.6%) are currently living with obesity.
• Obesity rates in Canadian adults are higher in men compared to women (28.0% versus 24.7%, respectively).

Geography and health are closely interconnected. Where we live greatly influences how we live and has a direct effect on our health experiences³.

What does "urban" and "rural" mean?

Statistics Canada’s Statistical Area Classification divides all Canadian municipalities into two large geographic sets⁴.

• Population centres - which we will refer to as “urban areas”, consist of areas with a high density concentration of population (i.e. areas with a population of at least 1,000 and a population density of at least 400 persons per km²).
• Rural area - All areas outside urban areas.

The sum of population centres and rural areas cover all Canada.

The rural area of Canada includes a combination of population living in rural areas embedded in urban areas as well as outside urban areas.

Credit: Image courtesy of Statistics Canada, rural area detailed definition. Accessed November 4, 2020

How does the prevalence of obesity in rural and urban Canada compare?

In Canada overall, the rate of obesity is higher for adults living in rural areas compared with those living in urban areas, independently of sex.

• In rural areas, about 1 in 3 Canadian adults are living with obesity (31.4%)
• In urban areas, about 1 in 4 Canadian adults are living with obesity (25.6%)

This means that there are on average 5.8 more cases of obesity per 100 adults living in rural areas compared with urban areas.

Figure 1. Obesity prevalence (%) in Canadian adults by rural-urban place of residence and by sex.

Source: Canadian Community Health Survey pooled data, 2015-2018, as reported in the CRFA.
Population: Adults aged 18+ years, all Canada and by sex.

Geographic trends of obesity observed in adults living in rural communities versus cities across Canada

Not all provinces show higher rates of obesity in rural compared to urban areas.

• Provinces with higher rates of adult obesity in rural compared with urban areas were Manitoba, Saskatchewan, Prince Edward Island, Ontario, Alberta, British Columbia and Quebec. In these provinces, rural obesity ranged from 3.1 to 7.4 percentage points higher than urban areas (Quebec 27.3% versus 24.2%; Manitoba 36.1% versus 28.7%).
• In Saskatchewan and Manitoba the rural rates of obesity were higher for men only, while in Quebec and Alberta the rates of obesity were higher in rural areas for women only.
• There were no significant differences in obesity rates between adults living in rural versus urban areas in New Brunswick, Newfoundland and Labrador, Nova Scotia, Nunavut, Yukon and the Northwest Territories.

Figure 2. Obesity prevalence (%) in Canadian adults by provinces and territories and by rural-urban place of residence

Source: Canadian Community Health Survey pooled data, 2015-2018, as reported in the CRFA.
*Significantly different when comparing rates of obesity among rural versus urban areas of the same province or territory.

The prevalence of obesity is higher in small cities compared to large metropolitan cities.

When looking at cities in Canada:

• The lowest rates of adult obesity were observed in the largest urban census metropolitan areas such as Montreal, Toronto and Vancouver.
• In general, obesity rates in adults tend to be higher in smaller cities. The obesity rate in the census agglomerations of Miramichi, Woodstock, Corner Brook, Cape Breton, Yellowknife, Brockville, Dawson Creek, Wood Buffalo and the City of Iqaluit is about 1.5 times the rate of the Canadian average (i.e. greater than 40% versus 26.6%).

Figure 3. Municipalities with the lowest and highest rates of obesity in Canada, adults aged 18 + years.

Source: Canadian Community Health Survey pooled data, 2015-2018, as reported in the CRFA.
Population: Adults aged 18+ years, selected ^^Census Metropolitan Area (CMA), ^Census Agglomeration (CA) and cities.

But, the urban-rural disparities in adult obesity are complex and multifactorial!

In the past, urbanization was considered one of the most important drivers of the rise in obesity in industrialized countries. Recent global and national studies show that urbanization of rural life has contributed to a larger increase in rural obesity^5,6.

This change in the geographic distribution of obesity can be partly explained by the growing economic and social disadvantage that rural communities compared to urban cities experience. In particular, rural communities experience lower education and income, lower availability of healthy and fresh foods at a reasonable cost, less access to public transportation and lack of supportive environments to promote walkability, sports and recreational activities⁵.

Socioeconomic characteristics at the municipality level must be kept in mind to understand urban-rural disparities in obesity rates for adults when interpreting this data.

• In Canada overall, adult obesity is more prevalent among disadvantaged population groups such as those unemployed or with lower household income and education levels.

Figure 4. Obesity prevalence in Canadian adults by socio-economic status.

Source: Canadian Community Health Survey pooled data, 2015-2018, as reported in the CRFA.
Population: Adults aged 18+ years, all Canada.

Learn more

For more information, visit the Canadian Risk Factor Atlas (CRFA).

The CRFA permits data exploration by geography beyond rural versus population centre place of residence. Should you need further geographic data granularity, the CRFA is a new dynamic interface that integrates surveillance of key chronic disease and mental health risk factors (e.g. obesity, overweight, physical inactivity, fair or poor perceived health, lack of community support and sense of belonging, etc.) into a geospatial platform at multiple levels of geography from national to large municipalities and cities including the territorial capitals. Data can also be retrieved by other demographic and key socioeconomic determinants of health.