Gentle readers, this has been bugging me ever since I came across The Primal Blueprint one afternoon at Barnes & Noble, so you are going to have to humor me while I rant.
The premise of the book is that for optimal health, we should go back to eating the way our hunter-gatherer ancestors did. The author talks about how Paleolithic people ate a wider variety of foods than we do now, and so lived longer, healthier lives.
Now I am no expert in Paleolithic history, but even I know that while our ancestors would have foraged a wide variety of plants and fruits in the warm months, they would have subsisted on very little over the winter and gone hungry during times of drought. They ate a great deal of something like large game when it was available, and a lot of something else like berries when they were available. They did not necessarily have much day-to-day variety. And they certainly did not buy expensive dietary supplements over the internet.
Here's another thing I know: I've lived quite a bit longer than the average person in the Paleolithic, and I've subsisted mostly on chocolate.