I recently came across a piece of investigative journalism in The Guardian that I feel sums up the problems in nutritional guidelines, and how they got so screwed up, better than any other lay article that I have read. It is also a fascinating piece on how science self-corrects, but surprisingly slowly. It is well worth a read.
I would draw attention especially to the paragraph which reads ” This [the social community of scientists] makes scientific inquiry prone to the eternal rules of human social life: deference to the charismatic, herding toward the majority opinion, punishment for deviance, and intense discomfort with admitting error. Of course, such tendencies were exactly what the scientific method was invented to correct for, and in the long run it does a good job of it. In the long run, however, we’re all dead, quite possibly sooner than we would be if we hadn’t been following a diet based on poor advice.”
http://www.theguardian.com/society/2016/apr/07/the-sugar-conspiracy-robert-lustig-john-yudkin
My urban homestead 
Posted by mortaltree on April 26, 2016 at 5:30 pm
Very good article. Thank you so much for sharing.
Posted by wooddogs3 on April 27, 2016 at 6:58 am
It’s a meticulously researched case history of how medical ideas get squashed, at least temporarily, and long enough to do some serious harm. More often than not this happens through the “great man” model, where a charismatic, irascible, basically narcissistic man stands firm against new incoming data, whether on a very large scale like Ancel Keyes or on lower levels of hierarchy.
Honest medical school professors tell their students “Half of what we’ve taught you is wrong. The problem is that we don’t yet know which half.”
Posted by mortaltree on April 27, 2016 at 8:03 am
While exact recommendations about diet are necessary to get anywhere when studying health, articles like this make me wonder how much we might advance ourselves if we put more emphasis on the practices of correctly reading and meticulously reviewing actual studies among consumers and researchers alike. I noted a couple of points in the article where someone making a comment about a study had to admit they had barely read it, if at all. Knowing no one else would be so self informing as to simply read the document themselves, why should they? I find among consumers that directly informing oneself by reading a high quality study not chewed to bits like baby food is looked down upon as work rather than a privilege. It puts things into perspective to consider how in the not so distant past people like Nicholas Culpepper was risking everything to transcribe the literally latin texts of the herbal schools to the ‘vulgar’ tungue so the people could heal themselves. Even still he takes a very condescending tone in the work, and is clear in informing the reader that he assumes most commonfolk won’t understand what has been put before them. Nevertheless, he puts it before them.