Where can I find surveys on obesity?

I am looking for surveys on obesity in North Americans, preferably Canadians. I am interested in surveys that cover any aspects of this problem e.g. exercise factors, diet, lifestyle etc. Are there any sites out there that have this sort of info? I looked at the Health Canada website but didn’t find anything specific.

You can start at http://www.cdc.gov/nccdphp/dnpa/obesity/index.htm