Mike, I'd just like to elaborate a tiny bit on what JS just said: if the cows (or other livestock we raise for consumption) are raised on ranches, consuming grass as they're meant to, not only is the meat they provide more nutritious, but the ranches where they leave provide habitat for myriad other plant and animal species that can coexist with the roaming of livestock. It's a total reversal of the environmental devastation that results from the factory farming model, and far less damaging than the prospect of feeding the world via grain-centered agriculture even if factory farming is taken out of the equation.

The other note: requirement for vitamin C is significantly reduced by the metabolic changes that result from a diet centered around protein and fat, rather than carbohydrates. However, some from plant sources is likely necessary for people in most parts of the world; the often-cited inuit had access to food sources like whale skin, which is extremely rich in vitamin C. The adrenal glands (if I recall correctly) of most animals are also rich in vitamin C, and could in theory fulfill needs for vitamin C, but I suspect most people don't have ready access to such obscure offal. So zero-carbing is kind of like veganism, in the sense that it can be done healthily (though perhaps not optimally) but to do so requires carefully selected foods from often geographically disparate sources and possibly supplementation. Neither is really representative of what could be considered the "natural" diet of homo sapiens (if there is such a thing).

Good to see sane comments from the vegan camp! Posters on both extremes can get pretty rabid at times.

JS and Erik -- Thanks for the comments. I'll try to read 'Meat: A Benign Extravagance'. I am actually completely open to the possibility of changing my mind on the subject. My beliefs are rooted in reasons and information, and if those change, I have no categorical need to adhere to the previous conclusions. The theoretical issue I see is just the scale of it though. I have a very hard time imagining that we will ever have sustainable ranch-fed beef production that is affordable for the average person with populations at the current levels. I agree that the grain subsidies are the root of many, many problems, and have greatly reduced available farm lands for both better agricultural variety and for livestock grazing, and I appreciate that paleos and vegans can unite in fighting that, but it still seems hard to imagine that a system that supports the population densities of today will ever be able to provide significant portions of meat multiple times a day to everyone without resulting in horrible treatment of animals, dangerous health conditions and massive amounts of waste byproducts. Actually, in thinking about the resource usage issue, I'd say they probably use the most minimal possible resources at the moment for animal production, since that reduces their costs. Unfortunately the more minimal the resource usage, the worse are the conditions for the animals and the resulting health dangers and meat/dairy quality.

I realize you guys are pushing for better animal husbandry conditions, and I applaud that, but unless you can convince everyone to be a demanding consumer *and* make sure that animals are ranch fed by regulation and enforcement, I would expect converting everyone to a more meat heavy diet would just make the situation worse. A lot of it unfortunately comes down to cost. People, particularly in the US, have become accustomed to really cheap food. Improving the quality of a vegan diet is minimally expensive and enforces local produce markets and agricultural variety. Increasing the quality of a paleo diet is significantly more expensive and requires quite a bit more land usage because you first have to raise the feed for the animals and then raise the animals, and you have to do it all in a sustainable, healthy way. I guess ranch scenarios may help by utilizing large naturally growing grass regions instead of separately growing feed for the livestock, but we're in a pretty nasty day and age for making that happen. I just don't see people being willing to spend the extra money and that is the motivator for everything. That being said, I also expect minimal progress to ever be made on the vegan front as a large scale movement because, well, people like bacon 😉

So ultimately I do what I do because I feel like it has minimal impact, I still enjoy my life and eat healthy (albeit with a decent bit of extra effort), and I feel like it is ultimately a sustainable practice that I want to help contribute to financially and by improving the body of knowledge about how to live vegan. I don't disagree that there is potential for paleo and other omnivore diets being sustainable in the long term, but I feel like there are a LOT of infrastructure changes that would have to happen to make it affordable to the average person without simultaneously compromising quality, health and animal treatment concerns. We should fight for those infrastructure changes because they benefit everyone, and we should do that by being responsible consumers and verbal advocates. Unfortunately for a lot of vegans, I think the entire concept of killing animals for food is repulsive. I don't have any major issue with other people killing animals for food, even though I choose not to do it, which is why I seem more sane to you 😉 My concerns are with animal treatment and environmental concerns, and I think the end results of those interests line up almost perfectly with a lot of the paleo community, with the caveat that I see the road to sustainable meat production being a good bit longer than the road to sustainable agriculture production from where we are now. It is still worth working on both though.

Thanks for the feedback, and I'll do my best to read some of the literature you've referenced. I'm all about myth debunking, so hopefully that book will make me have more optimism about sustainable meat production.

Alright, Mike, I just wrote up some expanded thoughts on the topic and I quoted your above comment; I hope you don't mind. You can read the post , and if you feel like I took your statements out of context or anything be sure to let me know. I feel like this is a very worthwhile conversation.

JS, awesome article. I've told vegans about digestion of meat vs plant matter but they get all worked up and angry about it. "You're rotting inside!", "You're a murderer", "We're meant to eat fruit like chimps" etc.

That aside, Mike you sound like one of the nicest vegans I've ever come across! 🙂

I think I love you and your matter of fact writing style thank you!

Any vegans who are vegan for animal cruelty sake should know that plants scream too ya know! you just can't hear it! The natural order is what it is. Life begets life begets life begets life....

Thank you! after going paleo w/dairy, (high animal fat, no grains) my body loves me. I ask for well marbled beef and fatty wild salmon. YUM!!!!!

One minor quibble... termites can digest cellulose. According to their Wikipedia article, they often do it with the help of prokaryotic symbionts, but they are apparently capable of doing it on their own if they must.

All in all, an excellent article! I just had to pick on the bit about no animals digesting cellulose, but it was meant as a sign of affection for a well-written, funny article that *gasp* contains SCIENCE!

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