Obesity - The key figures according to Canada's statistics
Situation in Canada (2004-2005)
According to Statistics Canada’s published data for 2005, the rate of Canadians in the obese category (BMI higher than 30kg/m2) has almost doubled between 1978 and 2005, rising from 13.8% to 24.3% of the adult population, that is almost 1 in 4 individuals (see table 1). In 2005, the number of obese Canadians 18 or older was 5.5 million; 36% of the adult population was considered overweight; and 39% had a healthy weight. Underweight individuals represented 2% of the population.
In Québec, the proportion of obese individuals was 22% in 2004. Even though this is still lower than the national percentage, the gap is rapidly being filled. The Montréal and Québec regions are less affected, whereas Abitibi-Témiscamingue, Outaouais and the Gaspé peninsula are the most affected. British Columbia is the only province with an obesity prevalence lower than Québec’s.
Over the last decade in the United States, the increase in obesity has been definitely more significant that in Canada. The American statistics show, using measuring tools similar to those used in Canada, that 30% of the adult population (18 or older) was considered obese in 2004.
The proportion of obese persons increases with age, rising from 11% for 20-24-year olds to 29.7% for 45-64-year olds. The greatest increased is attributed to 45-54 year old men.
The progression of obesity is the greatest for individuals affected by extreme obesity (BMI over 40). The increase has tripled within the last 25 years, rising from 0.9% in 1978 to 2.7% in 2004. In Canada, the rate of extreme obesity was at 2.7% in 2004. Noteworthy is the fact that women are twice as many as men to be affected by extreme obesity (class III, table 2).
This problematic trend also concerns children. Within the Canadian population, more than a quarter of the children are overweight.
Table 1. Prevalence of obesity in Canada for 1978-2005 (measured values)
Table 2. Prevalence of obesity in Canada, by gender, in 2004 (measured values).
Data source: 2004 Canadian Community Health Survey: Nutrition.
The use of different methodologies might bias data interpretation. For example, for many years in Québec and Canada, overweight was defined as a BMI of 27 or more. It is therefore important to exercise prudence in the interpretation of results from Québec social and health surveys prior to 2000. Also, many surveys conducted before 2004, including those of Statistics Canada, used reported weights and heights rather than using weights and heights measured directly. People tend to minimize their body weight and to overestimate their height, which creates an underestimation of the BMI as well as that of overweight and obesity prevalence. This explains the deviations of prevalence between the 2003 and 2004 Statistics Canada surveys.
The use of similar assessment methods allows, at a minimum, to follow trends in time even when using potentially inaccurate data, however, the use of different methods renders the comparison of surveys challenging.
Incidence, prevalence & co-morbidity (IOTF)