I have read a lot about people's experiences with The Paleo Diet, but I have never really shared my own views about it, other than to say that I have tried it. So I thought I would elaborate on my experience.
First off, I just want to say that I have tried another low carb diet--The Atkins Diet and my experience with that was AWFUL! Just to share a little TMI, I got the worst case of constipation of my life and almost had to go to the hospital emergency room. Fortunately the laxatives I was taking finally kicked in and after spending a day in the bathroom, I swore off Atkins forever.
However, my experience with The Paleo Diet by Dr. Loren Cordain was completely different and not at all unpleasant. I felt great and even lost some weight. I was particularly happy that The Paleo Diet included a variety of vegetables, nuts and seeds, plus a few fruits. So why did I abandon it and go back to eating a plant-based diet? For one thing, my conscious got the better of me, and for another thing I just didn't think it was sustainable either for me or the planet.
The Paleo Diet for those who are unfamiliar with it, is about trying to eat like our ancient ancestors did during the Paleolithic Era (stone age). Through archaeological and anthropological studies, Dr. Cordain has concluded that humans ate a diet of lean wild game meat and/or fish/shellfish, birds/eggs, plants and of course no processed food or dairy products. The problem with his conclusions is that if humans eat a diet of lean meat without enough carbohydrates and/or fat, they will have symptoms of protein toxicity. This was dubbed "rabbit starvation" by historians to describe why some early explorers died when all they had to eat were rabbits. So in order to get around this, most people who follow a paleo-style diet eat more fat than even Dr. Cordain recommends. If they don't do that, then they have to eat a LOT of carbs. Then it wouldn't be a "low-carb" diet. Also, Dr. Cordain recommends eating wild game meat rather than grain-fed meat. Unless you are a hunter with a large freezer to store the wild game you kill, it is difficult to eat this way. There are some companies that sell "exotic meat" online, but such meat comes from game ranches where animals are fenced in and yet still hunted or where deer are raised much like cattle. So they wouldn't really be "wild" would they? I went to one of those websites and the prices of the "wild" game were ridiculously high. The same holds true of grass-fed beef. While not as expensive as buying game meat, it is still too expensive for most people to eat on a daily basis.
While I love animals, I am not exactly an animal rights activist. People had to eat meat for thousands of years before farming and I certainly don't consider them murderers. However in this day and age, I think there are perfectly sensible ways to avoid eating meat and many reasons to do so.
For instance, according to a U.N. report several years ago, raising animals for human consumption is not a sustainable way to feed the ever increasing world population. More and more forests will have to be cleared in order to have enough land to raise cattle. This has destroyed a lot of wild animal habitats, resulting in many animals being put on endangered species lists. Most of the grain and soybeans in the world is grown to feed cattle, hogs and poultry. By eliminating the need to feed animals, such grains can be used solely for human consumption. In addition the huge manure lagoons that accompany livestock production have been polluting our rivers and streams and killing fish as well as contaminating drinking water.
I also believe modern factory farming is cruel and completely unnecessary. Why should animals suffer for months or years before becoming our dinner? While I believe humans are omnivores, that doesn't mean there are not ways around it so that we can not only feed ourselves far into the future, but protect the animals with which we share this planet.
Humans are a successful species because we have learned to adapt to the challenges of surviving on earth. In order to continue to survive, we need to continue to adapt to the changing times. In the past we exploited the environment and animals (as well as each other), but hopefully we've learned that we need to work with the environment and find ways to survive without depleting all our natural resources or destroying the planet and our fellow inhabitants.
So I suppose you can say I am an environmental or ecological vegan. That is why I have chosen not to eat animals, even though millions of my ancestors did. They used the knowledge they had at the time to survive. Modern humans have much more knowledge at their disposal than those who lived in the Paleolithic Era. We can eat healthy and still protect our world.