Weighty Matters, which won the 2007 Canadian Blog Award for Best Sci/Tech Blog, is a Blogger Blog of Note.
Yoni Freedhoff, a Canadian doctor, writes a lot about the role of advertising in our health, especially false or misleading claims in food advertising. He exposes the links between Health Canada's Food Guide and the food industry. He has testified about the Food Guide before the House of Commons, and has a lot of interesting things to say about it - almost all negative.
Dr Freedhoff also links to some excellent sites, such as Quackwatch, Center for Science in the Public Interest, the Cornell Food and Brand Labs (a terrific place), and the great Marion Nestle. You might know Nestle from Michael Moore's "Sicko". I've been reading her work, off and on, for many years. She's brilliant, and she's truly independent.
I don't agree with all of Freedhoff's perspectives: I especially think he overemphasizes weight as a measure of health, and has an unrealistic and unhealthy definition of obesity. But a critical eye towards the influence of corporate advertising on our eating habits - and thus, on our bodies and our health, the very core of our existence - is so important, and so welcome.