Physical inactivity, dietary factors, obesity and being overweight

Dietary modification is another important approach to cancer control. There is a link between being overweight or obese and many types of cancer such as cancer of the oesophagus, colon/rectum, breast, endometrium and kidney. Diets high in fruits and vegetables may have a protective effect against many cancers. Conversely, excess consumption of red and preserved meat may be associated with an increased risk of colorectal cancer. In addition, healthy eating habits that prevent the development of diet-associated cancers will also lower the risk of cardiovascular disease.

Regular physical activity and the maintenance of a healthy body weight, along with a healthy diet, will considerably reduce cancer risk. The Canadian Cancer Society states that about one third of all cancers can be prevented by eating well, being active and maintaining a healthy body weight.

Specific to physical activitiy, active men and women have a 30-40% reduction in the risk of developing colon cancer compared to inactive people. There is also a 20-30% decrease in risk of breast cancer in active women1.

Recently, a report has been released by the World Cancer Research Fund called Food, Nutrition, Physical Activity and the Prevention of Cancer: A Global Perspective. It details the role of diet and weight in cancer development. The full report can be viewed here. The report outlines certain dietary risk factors of specific cancers, including cancers of the mouth, pharynx, larynx, nasopharynx, oesophagus, lung, stomach, pancreas, gallbladder, liver, colon, rectum, breast, ovaries, endometrium, cervix, prostate, kidney, bladder and skin.

National policies and programmes should be implemented to raise awareness and reduce exposure to cancer risk factors, and to ensure that people are provided with the information and support they need to adopt healthy lifestyles.

For more information:

World Health Organization website, November 2012

Canadian Cancer Socety, July 2015


1. Lee, I.M. (2003) Physical activity and cancer prevention – data from epidemiologic studies. Medicine and Science in Sports and Exercise 35: 1823-1827.

2. Key, T.J., Allen, N. E., Spencer, E.A., Travis, R.C. (2002) The effect of diet on risk of cancer. The Lancet 360: 861-868.