"The racial make-up of the two countries might explain some of the differences, as research has shown that obesity rates vary by ethnic origin. Nonetheless, when obesity rates of White Americans and Canadians are compared, White women in the United States were significantly more likely than those in Canada to be obese: 30.3% versus 24.8%. However, the percentages of White American and Canadian men who were obese did not differ."
From: http://www.statcan.gc.ca/pub/82-620-m/2005001/article/adults...
"The racial make-up of the two countries might explain some of the differences, as research has shown that obesity rates vary by ethnic origin. Nonetheless, when obesity rates of White Americans and Canadians are compared, White women in the United States were significantly more likely than those in Canada to be obese: 30.3% versus 24.8%. However, the percentages of White American and Canadian men who were obese did not differ."