Another leading cause of illness is obesity: 48% of Canadian adults are overweight, and 14% are obese; that is, they have a body mass index of more than thirty. These rates compare to 55% overweight and 23% obese in the United States. About 15% of men and 22% of women in European countries are considered obese. In total, according to the Worldwatch Institute in Washington, USA, the world now has as many overfed as underfed people: 1.2 billion of each.

In 1996-1997, 57% of Canadians fifteen years and older exercised three times a week, 18.5% once a week, and 21.6% less than once weekly or never.