I just finished a book that talks about how much humans have evolved since paleolithic times, largely as a result of agriculture. I don't really buy into the notion that our bodies are "designed" for an environment that existed hundreds of thousands of years ago. Adult humans couldn't digest animal milk back in those days, for example, but now most of us (definitely those of northern European descent) can, because we have evolved to be able to do so. But the paleo diet treats dairy as off-limits.

There are some good aspects of the paleo diet, however, like eating a lot more greens and fewer processed carbs. The less processed anything is, the better.

A lot of people say they feel better when they drastically reduce carbs. I end up miserable. I mostly eat whole grains, but I do need them or I end up with headaches and lightheadedness and I'm hungry within about 30 minutes of eating. :-(