See this article from the scientific journal _Science_ from 2001 (not endorsing the linked website, it was just the first non-paywalled location of the article): http://garytaubes.com/wp-content/uploads/2011/08/Science-The...

The fallacies around dietary guidelines have been known to the scientific community for over 15 years at least. I read that article when it was in the original issue and I was dumbfounded by the slapdash way nutrition guidelines are established with minimal proof.