Do dietary guidelines do more harm than good?

I wouldn’t even ask such a silly question if the American Journal of Preventive Medicine wasn’t going to publish a paper arguing just this point. Along with one of the editors of that journal, I wrote an editorial commenting on the paper, to which its authors added a rebuttal to our editorial. The authors argue that the government has no business issuing advice based on weak evidence. I would agree except that evidence will never be as good as we wish it would be because research on human nutrition is really, really hard to do. And when it comes to diet, dietary guidelines are not exactly radical; the basic advice hasn’t changed in 50 years. I summarize it like this: “eat less, move more, eat plenty of fruits and vegetables, and don’t eat too much junk food.” Michael Pollan gets it down to 7 words: “Eat food. Not too much. Mostly plants.” The Dietary Guidelines published in 2005 may take 70 pages, but in general, they say pretty much the same thing.