The Association Between Cancer, Body Weight, and Inactivity.

Chris Running in Jasper

Chris Running in Jasper

Obesity and inactivity have been correlated to many chronic illnesses but we have just recently began to study the it’s interrelationship. Dr. Darren Brenner recently wrote a paper titled: “Caner incidence due to excess body weight and leisure-time physical inactivity in Canada: Implications for prevention” where he talked about the potential relationship between these modifiable factors and cancer(1).  We already know being overweight and having obesity have already been linked to the following cancers:

  • Colon
  • Kidney
  • Endometrial
  • Esophageal
  • Post menopausal breast cancer
  • Pancreatic
  • Ovarian
  • and probably gall bladder

In 2011, Statistics Canada(2) and the Public Health Agency of Canada(3) found that %52.2 of all Canadians were self reported as overweight and obese, and %54 of Canadians were classified as physically inactive. Furthermore it’s reported that only %5 of Canadian adults attain five days of 30 minutes of moderate to vigorous daily physical activity(4).   Brenner states that energy imbalance, energy/caloric intake exceeding energy expenditure with physical activity, is ranked at the top of the list of the causes for cancer.  After analysis of the Canadian Community Health Survey in 2000/2001 and 2008 Brenner found the following:

  • Between %7.88 to %12.51 of all cases of cancer in 2007 were associated with lower physical activity and excess body weight.
  • Women have a higher incidence of cancers associated with physical activity and body weight.

While another article (5) reported that the notion of energy imbalance due to physical activity is most likely due to:

  • changes in levels of sex hormones
  • changes in immune function
  • chronic low grade inflammation
  • changes in vitamin D levels

Ultimately it’s small changes in our daily actions that are entirely attainable that will change the probability of cancer. 30 minutes of moderate to intense physical activity (%60-80 maximum heart rate) five days a week, and eating less processed, nutritionally dense foods will greatly reduce the probability of cancer.


(1) Brenner, D.R. Cancer Incidence due to excess body weight and leisure-time physical inactivity in Canada: Impocations for prevention, Prev. Med. (2014),

(2) Statistics Canada, 2011. Table 105-0501 – HEalth Indicator Profile, Annual Estimates, by Age group and Sex, Canada, Provinces, Territories, HEalth Regions (2011 boundaries) and Peer Groups, Occasional, CANSIM (Database).

(3) Public Health Agency of Canada, 2011. Obesity in Canada. A Joint Report from the Public Health Agency of Canada and the Canadian Institute for Health Information, Ottawa, Ontario.

(4) Friedenreich, C.M., Neilson, H.K., Lynch, B.M., 2010. State of the Epidemiological Evidence on Physical Activity and Cancer PRevention. Eur. J. Cancer 46, 2593 – 2604.

About Chris Tse

I’m a scientist turned owner of Blitz Conditioning, a Fitness Columnist at CBC Radio on Thursdays at 8:20 am, and owner of Tse Social Strategy. Follow me on Twitter or Read my full bio.

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