A: Vegetarians.

Oh, you wanted scientific arguments. Seriously, though, I'm not sure how well scientific arguments work to convert people away from what are essentially emotional decisions. But the bibliography in the back of The Vegetarian Myth might be a good place to start, if you want to try.

These might not have the scientific references you are looking for, but they provide an articulation of main points or arguments that I've found to have a certain rhetorical bite among even the most articulate vegetarians.

1. Our knowledge of human evolution is clear and not disputed: our ancestors ate meat - as evidenced by (a) our digestive systems, which are adapted to process meat, and (b) our micro and macro nutritional needs, which are well aligned with meat's nutritional profile.

2. Everything follows from this evolutionary fact, such as the superior bioavailability of the nutrients in meat, which is enhanced by the macro properties of meat like, e.g., being accompanied by fat (most vitamins are fat soluble).

3. Look at the supplement aisle next time you visit CVS or WF: the majority of them are products found in animal products: choline, omega 3, taurine, b12, vitamin A, etc. Toward similar ends, go to fitday and compare the nutrient profiles of liver, steak, eggs, and broccoli. Hint: broccoli performs well, but it loses comparatively, and that's without introducing bioavailability issues.

4. Meat makes you strong and lean; veggies make you weak and puffy. Vegetarianism mistakenly tries to have nutritionally supplementary foods play primary dietary roles, an odd task that requires numerous consequent efforts in order to maintain feasibility, let alone optimal health. This move against simplicity is a simple but clear signal from nature (read: our evolved biology).

5. While CAFO animals are unethically treated, organic pastured animals live happy lives and their consumers have no reason to morally question their slaughter, which is probably the most humane food-motivated killing in the animal kingdom. When we support the right farming practices, both parties win. This should be embraced as a source of moral or ethical pride.

6. Most seemingly pro-vegetarian empirical studies suffer from an inability to (or simple failure to) control for confounding predictor variables -- namely, whatever other health promoting behaviors that S's who choose to eat vegetarian also choose bc they perceive them as such. Control for these, and watch the benefits disappear.

7. Being vegetarian is likely to result in increased consumption of sugar, processed carbohydrate, and soy or soy-based foods. This isnt a necessary consequence, but it is highly likely bc foods containing them ease the burden of maintaining the diet.

I like the argument that meat (and cooking) made us human.

See Richard Wrangham's - Catching Fire: How Cooking Made Us Human

http://www.amazon.com/Catching-Fire-Cooking-Made-Human/dp/0465013627

Also, Dr. Mike Eades has a couple of great posts on why the evolution of the brain requires meat: (the second post is the payoff)

http://www.proteinpower.com/drmike/peta-cspi-and-other-menaces/are-we-meat-eaters-or-vegetarians-part-i/

http://www.proteinpower.com/drmike/low-carb-library/are-we-meat-eaters-or-vegetarians-part-ii/

I am tempted to say the best argument is 'a mirror'. ;)

However, one book I really would recommend to anyone who is:

1. interested in sustainable farming, or,
2. vegetarian/vegan for ethical reasons

is a book by Simon Fairlie called 'Meat - A Benign Extravagence'. It is profound in its insight although tough going in one or two places, but ultimately worth the effort.

Fairlie shines a light in to the symbiotic relationship between all animals (ourselves included) and farming, and makes a case for 'at least some pastoral farming' in any sustainable model. From this he establishes a 'default' level of meat consumption and the case for using animals as a sustainable source of farm-power.

The Honey Badger. nuff said

Linda McCartney?

First wife of Paul McCartney, Beatle, long time vegan/vegetarian died at age 56 in 1998 from breast cancer and liver cancer. Founded a vegetarian food company that is still in business after being sold twice. Both McCartneys were/are outspoken advocates of vegetarianism and a campaigner for animal rights.

I remember people lamenting she was doing everything right, juicing fresh organic veggies, eating right, and never eating any animal products.

http://en.wikipedia.org/wiki/Linda_McCartney#Vegetarianism.2C_activism_and_lifestyle

Now to be fair, can anyone point to any famous paleo meat eater advocate that have met an early demise from cancer or other disease. Or have us paleo folks just not been around that long? Is it going to take another 20 years for paleo to become mainstream?

Meat = Delicious

you need to head for Google Scholar. A lot of those articles aren't accessible without paying but many are free. the vegetarian myth is great but it is certainly not peer reviewed and it has a very clear and biased agenda. if you want scientific arguments you need scientific papers from respected journals.

It certain parts, useful crop cultivation is limited. In those situations it is less food efficient overall than including pastured meats.

All the studies I've seen indicate that vegetarians are healthier than other groups on average, and have the lowest chance of mortality (eg. meta study puts it at ~0.86, 0.87 for other omnivores, 1.0 for vegans and high meat groups - none of the differences are all that impressive though).

Your going to have trouble finding studies proving vegetarianism is good, as it usually leads to better health outcomes than the normal diet, and lacks the deficiencies required by vegans.

You'll die earlier gets their attn most.

here's some stuff.

http://www.westonaprice.org/abcs-of-nutrition/267-myths-of-vegetarianism

Steve Jobs?

Not to bust on the guy (who I respect, despite him being a bit of a despot, and even if I didn't like him, I wouldn't pick on his illness), but he has been "seriously vegetarian/vegan" his entire life (at one point he was a "fruititarian" and his coworkers begged him to eat a slice of bread). The poor guy got pancreatic cancer.

This is actually predicted by those skeptical of the vegetarian diet, which they believe causes overproduction of insulin and puts too much of a strain on the pancreas.

There was also a study in India that found that cardiovascular disease was 2x as prevalent in the regions that were vegetarian. They are guessing that the cause is low vitamin B intake due to poor diet. For example:

http://articles.timesofindia.indiatimes.com/2011-05-02/health/29391798_1_omega-3-vegans-fatty-acids

Ummm, you don't get to eat meat?

Most domesticated animals exist as it is my intention to eat them. Thats not cruelty thats symbosis.

Most domesticated animals exist as it is my intention to eat them. Thats not cruelty thats symbosis.

Acne. Osteoporosis. Alec Baldwin. Monsanto, DuPont, the World Bank - you couldn't pragmatically have worldwide vegetarianism without genetically modified foods, commercial Big Farms, forest depletion, pesticides, killing of "pests," and forcing subsistence farmers in 3rd World countries to grow commercial crops.

Having a flatter stomach, bigger muscles and more energy than your vegetarian friends and embracing the glory of your animal nature when they give the stinkeye to your meal when you go out for dinner.

As far as scientific arguments go, have your friends check out studies on the Inuit, Masai warriors and the declining health of Native Americans like the Lakota who were once hunter/gatherers and now subsisting on a mostly vegetarian (commodity) diet.

Think of all the species that would be extinct (much less numerous, anyway) if we didn't eat them.

Weston A. Price's Nutrition and Physical Degeneration Lierre Keith's The Vegetarian Myth

You can't eat bacon.

But my favorite thing to do? Hand them "the vegetarian myth" by Lierre Keith to read.

A vegetarian being told by me, the bacon eater, to get off their high horse? Ignored. It's harder to ignore a woman who destroyed her health and everything she held dear following a vegetarian and for a while, a vegan diet. Besides, the stuff she's talking about is backed up with facts, personal experimentation, and a lot of research. Stuff I didn't even understand went through a person's mind, so it's nice to have a different perspective on why people are vegetarian or vegan.

Though really, everyone should read that book. Scary stuff about soybeans and other things vegetarians and people on SAD eat. I don't think you could pay me money to eat soybeans after reading all the bad stuff about it.

So when are 'The best arguments against vegetarianism' going to be posted?