"So to take us to task to try to explain what we are learning without doing the research and reading yourself is a bit lopsided."
I must be getting sloppy with my language, Miguel, because you persist in reading the worst into my post. I am not taking you or anybody else to task. This is a discussion on a subject that I find very interesting and which has given me a lot to think about, and also have studied to a fair degree from a different perspective. However, when I encounter a statement that I disagree with, I feel it is my right to register my disagreement, accompanied by my reasoning. My impression to date is that you find this offensive, and I am sorry for that, but it will not cause me to cease posting. To be clear, I am NOT taking Paleo studies, OR the Paleo diet in its entirety, lightly. There is one main area that I find problematic for the general population, by which I mean those who are not trying to lose weight or suffer from type 2 diabetes, and that is the ketogenic diet. There is ample evidence to prove that humans, indeed all mammals, are designed to use glucose as a substrate for metabolism, along with fat and a small amount of protein. Google up "mammals AND glycogen" if you don't believe me, or "primates AND glycogen". This is more than enough to convince me that hunter gatherers never lived in a constant state of ketosis, rather than exclusively when they were short of food. Nor should most modern humans. Brian's explanation of the Paleo diet convinced me that it is a perfectly viable diet for those who choose it, but by no means the only one, much less the optimal one. That remains to be determined. To those who choose the ketogenic diet, I wish them well and hope they remain healthy over the long term.
"Others can resist the notion of a range of healthy recommendations all they want, especially the emerging knowledge coming out about grains, but the truth is that there is a very real, very visible, and very persistent problem with obesity in American (and to a lesser extent elsewhere). People are unnaturally fat. And getting worse all the time. Prople's exercise habits have not changed that drastically in the last 50 years, and yet obesity rates have risen to epidemic proportions."
I will refer you back to my previous observations about civilizations being based on grains. They have been remarkably successful for millenia, including here in America up until about 40-50 years ago. What has changed is that people are growing more sedentary, stressed by modern life, and taking an increasing part of their food from extremely unhealthy sources, eg refined sugar, white flour carbs, etc, and are constantly bombarded with advertisements for unhealthy food. To make matters worse, food is everywhere. Contrary to what you say, people's exercise habit HAVE changed in the last 50 years. That is so well established as to be unworthy of argument. Kids are spending more time inside, either watching TV, playing video games, twittering, etc, and less time moving around. Physical education is rarely offered in schools anymore. It was mandatory when I was a kid,and when school was out we were out the door to play sports and run around. No one drove a car to school, we walked. Today the school parking lots of high schools are fulls of student cars, and younger kids ride a bus to school. The same goes for a lot of adults, regarding a sedentary life style. It is no surprise, given the above, that there is an epidemic of obesity and type 2 diabetes, both of which were rare 50 years ago.
"I don't see how you can just dismiss what they are saying."
I do NOT dismiss what they are saying. I didn't know first hand a lot of what they are saying, at least until this thread. I do, and shall continue to, question the ketogenic diet for the general population, as well as the statements made here by some that the Paleo diet is the answer to mankind's dietary problems. It is much more complicated than that.