From the perspective of a palaeoanthropology nerd... there is no logic behind the majority of what gets touted as paleo on the internet. It doesn't bear any resemblance to actual palaeolithic diets, and most people peddling it don't seem to know very much about palaeoanthropology at all. (there may be some exceptions, there are people out there who take a much more informed approach to the paleo diet, but they tend to do it quietly and not mouth off about wheat being unfit for human consumption or whatever else)

the original concept it was based on is fairly sound, and in fact when I was at uni back in the late 90s, one of the palaeoanthropology lecturers actually taught us about the concept of the paleo diet, but what he said was very, very different to what gets touted on the internet nowadays. It's based on comparisons between modern hunter-gatherers and post-industrical cultures, and also the fact that a lot of foods that people are commonly allergic or intolerant to are those that have been introduced or significantly changed by selective breeding, since the start of the neolithic era (i.e. the start of farming, as opposed to hunter-gathering), e.g. dairy (only breastmilk for babies and small kids was available prior to dairy farming) and wheat (some varieties have been subjected to millenia of selective breeding).

The way we live our lives in modern times is very different to how our fairly recent ancestors lived, in fact the last 10,000 years or so has seen very rapid cultural and technological development that's happened more quickly than we've been able to adapt (for the most part, but there has been adaptation) - so we're on the whole better suited to hunter-gatherer life than sedentary post-industrial life.... but a lot of it is about being sedentary as opposed to walking for miles each day, carrying heavy things and exerting yourself for tasks like hunting. In terms of diet, lactose intolerance is more common in populations that have remained as hunter-gatherers until recent times (e.g. native Australians), but this proves that those who are cultures that have practiced dairy farming or herding for thousands of years actually have adapted to be able to digest lactose as adults. So while the principle that palaeo is based on is fairly sound, there is also evidence that many people have adapted to the post-neolithic diet. Additionally, humans' ecological niche is adaptability, we can adapt very well to a huge variety of cultures, diets, ways of living, so it doesn't stand to reason that we all have to imitate the diets of hunter-gatherers.

But I do think that there is a benefit to considering what our bodies are adapted for, and using this knowledge to improve our health. We are not adapted to be sedentary, we're adapted to be very active, and our ancestors didn't get to eat if they didn't exert themselves to obtain food. The modern obesity epidemic is mostly because it's too easy to get food. Even in the much more recent past people walked to the shops much more, they did more physical jobs, they did physical work in the home, e.g. washing clothes by hand, but now many people don't have to exert themselves for anything much. We're adapted to eat after exercising (as exercise was for the purpose of acquiring food), which is why good post-workout nutrition is very important. We're adapted to share food and enjoy eating as a social event (food sharing in humans seems to go back at least 2 million years according to the archaeological evidence, and probably a lot further seeing as chimpanzees occasionally do co-operative hunting and share the meat, which until recently was thought of as a purely human behaviour). Ignoring the social aspect of eating when trying to be healthy and lose fat can result in people being unable to stick to their eating plan, because they never eat out with friends, and they become miserable... because we didn't evolve to eat alone, we're not meeting our emotional needs if we always eat alone. So there is a lot that you can learn from viewing dieting and fat loss from an evolutionary perspective. But when you do that, what you end up with isn't the same as "The Paleo Diet" as you read about on the internet (though as I said before, there are paleo dieters who take a more intelligent approach.. but what you read most commonly online about it isn't that)

As for why (add food here) is included but (add another random food here) is not included, is because the people saying it don't know much about palaeoanthropology. Another example is why wheat is demonised but bananas are okay... they're both the same from an evolutionary perspective, i.e. both have been cultivated for around 10,000 years and due to selective breeding are very different to the wild varities... go take a look at a wild banana and you'll see what I mean!! Banana allergy is also pretty common, so it's like wheat in that respect too.

It does my head in how little people who promote "paleo" on the internet actually know about how "cavemen" actually lived (including the fact that most palaeolithic people probably didn't live in caves), it makes me cry sheldon tears ("I cry because people are stupid and that makes me sad") and you get them saying the most ridiculous things that make no sense whatsoever, which is a real shame because like i said approaching diet and fitness from an evolutionary perspective can be very beneficial. But in a lot of cases it's like they're getting their info on "paleo" by watching the Flintstones....

One can have a diet that is relatively "high" in corn consumption and if nutrient needs are being met through the other food selections (ie corn isn't pushing other needed nutrients off the table) then I don't see any problem with it. Context.

I started Paleo three weeks ago and I feel fab on it! I think that people should eat what they want to eat and diet how they want to diet. I don't go around preaching and I think that as long as its working then im happy!

I enjoy the fact that I am eating none (well certainly less) processed foods. Obviously I am not 100% paleo as that's difficult in this day and age!

I just think people need to appreciate different peoples approaches to life - you wouldn't go to a vegetarian you really should eat meat, or to someone on Paleo - you really should have some pasta and likewise people on paleo shouldn't be telling you what you should and shouldn't eat!

I don't have artificial sweetener anymore and my headaches and so on have gone.

I stick to meats, fish, fruits, veg, greek yogurt (am on tablets that mean I need calcium) and nuts and in this hot weather im really enjoying it!!

I think there may be a typo so just trying to clarify what you are saying in the bolded part.

I started Paleo three weeks ago and I feel fab on it! I think that people should eat what they want to eat and diet how they want to diet. I don't go around preaching and I think that as long as its working then im happy!

I enjoy the fact that I am eating none (well certainly less) processed foods. Obviously I am not 100% paleo as that's difficult in this day and age!

I just think people need to appreciate different peoples approaches to life - you wouldn't go to a vegetarian you really should eat meat, or to someone on Paleo - you really should have some pasta and likewise people on paleo shouldn't be telling you what you should and shouldn't eat!

I don't have artificial sweetener anymore and my headaches and so on have gone.

I stick to meats, fish, fruits, veg, greek yogurt (am on tablets that mean I need calcium) and nuts and in this hot weather im really enjoying it!!

I think there may be a typo so just trying to clarify what you are saying in the bolded part.

Sorry - only just seen this - and I meant you wouldn't go to a vegatarin, you really should EAT meat! its a persons lifestyle choice, well mine is anyway! :-)

I am still confused. Are you saying people should eat meat? Or that they should not go to a vegetarian for advice if they ate meat?