Michael Pollan explains what’s wrong with the pale diet. It's a short read with link to an in-depth podcast interview with Mr. Pollan. His advice to avoid any food that your great grandmother wouldn't recognize as food is a sound guideline.
"The paleo diet is hot. Those who follow it are attempting, they say, to mimic our ancient ancestors — minus the animal-skin fashions and the total lack of technology, of course. The adherents eschew what they believe comes from modern agriculture (wheat, dairy, legumes, for instance) and rely instead on meals full of meat, nuts, and vegetables . . . " Read more at Grist