If it were just an issue of media hype, that would be a valid explanation for the food pyramid failure.

But it's not just that. It's the fact that a) government experts believed it b) with high confidence that c) isn't justified, and d) are so confident that they plaster it in every classroom with all their authority behind it, and e) no scientific authorities go on record saying the real state of the research in case anyone bothers to get the real story.

You can't blame the media for those parts.