Modifiable Risk Factors - Overweight/Obesity
Key findings
The proportion of adults who are overweight or obese has been increasing for decades.[1] More recently, in 2017, approximately 63% of Ontarians ages 18 and older were overweight or obese. This rate was significantly higher in men than women, rural residents than urban residents, Canadian-born residents than immigrants, and those with high-school or lower education compared with post-secondary graduates. The rates did not differ by household income quintile.
Why is this important to Ontarians?
- Modifiable risk factors are behaviours and exposures that can lower or raise a person’s risk of cancer and that can be changed. Evidence confirms strong associations between adult body fatness and the risk of certain cancers. According to the comprehensive World Cancer Research Fund/American Institute for Cancer Research review, there is convincing evidence that adult body fatness increases the risk of developing colorectal and post-menopausal breast cancers, and probable evidence that they increase the risk of prostate cancer.[2]
- In Ontario, 8.2% of colorectal cancer cases and 8.0% of female breast cancer cases can be attributed to overweight or obesity in 2010.[3]
- Reporting on risk factor prevalence in Ontario is important to effectively monitor trends over time, support the development of health promotion and disease prevention strategies, and evaluate outcomes of provincial interventions.
See Modifiable Risk Factors Methodology for technical information.
| Country | Estimates, both sexes (percentage) | Estimates, men (percentage) | Estimates, women (percentage) |
|---|---|---|---|
| Netherlands[4] | 47.6 | 50.2 | 45.0 |
| Sweden[5] | 49.9 | 56.6 | 42.9 |
| United States[6] | 65.1 | 71.2 | 59.3 |
Notes:
- Overweight and obesity defined (adults): Body Mass Index (BMI) 25 or greater based on self-reported weight and height.
- There are slight differences in the year and age groups for each region’s data: Netherlands (2016 data of individuals ages 15 or older); Sweden (2018 data of individuals ages 16 and older); and United States (2018 data of individuals ages 18 and older).
Results
- Between 2015 and 2017, the proportion of Ontario adults ages 18 and older who were overweight or obese increased each year, from 60.5% in 2015 to 62.8% in 2017. Men were significantly more likely to be overweight or obese than women.
- From 2015 to 2017, rates of overweight or obesity in Ontario adults ages 25 and older were higher in rural residents (71.7%) compared with urban residents (63.4%); higher in less educated persons (about 70%) than in post-secondary graduates (62.2%); and higher in Canadian-born residents (66.9%) compared with immigrants (about 60%). Rates did not differ significantly by household income quintile.
Comparisons
Getting comparable data and measures from other jurisdictions is a challenge. Be aware of the different data definitions, methodologies and years used in indicators measured outside Ontario. Jurisdictional comparison is still useful to provide a rough indication of how well Ontario is doing relative to other provinces and countries.
- The rate of overweight or obesity in Ontario (62.8% in 2017) is higher than self-reported rates from the Netherlands (47.6% in 2016)[4] and Sweden (49.9% in 2018).[5] Ontario’s rate is lower than that reported in the United States in 2016 (65.1%).[6]
Opportunities
- This indicator needs improvement because the rates of overweight or obesity have been increasing and show differences by socio-demographic factors. Exposure to some risk factors is higher in particular social, economic or geographic populations. Populations facing health inequities experience higher incidence and mortality rates for certain cancers.
- Obesity is a complex issue with multiple causes and contributors. Eating a diet rich in vegetables and fruit, and participating in moderate-to-vigorous physical activity contribute to maintaining a healthy weight. Those actions also provide independent health benefits to prevent chronic disease, specifically cancer.
- Evidence shows that healthy public policy and community-wide programs work better to reduce the prevalence of modifiable risk factors at a population-level than those that focus on changing individuals’ behaviours. Prevention policies and programs to reduce the prevalence of unhealthy eating and physical inactivity may also help reduce the prevalence of overweight and obesity.
- The Prevention System Quality Index is a series of reports that monitor population-level policies and programs that can reduce cancer risk factors and exposures in the Ontario population. The reports include evidence-based recommendations to strengthen cancer prevention in Ontario.[7]