Saturday, June 13, 2009

Eating meat is bad for you and the world... kind of

When reading a recent Foreign Policy article, I was reminded of the growing movement toward vegetarianism and away from meat or animal food products. I was also reminded of the nutritional falsehoods being touted in this campaign.

There are three essential lines of argument against eating meat, all of which are discussed in the linked article above.

First, meat is bad for a human's health. Second, the meat industry emits a tremendous amount of greenhouse gas (GHG) emissions, which is contributing to climate change. Third, killing animals for food is immoral in and of itself.

I disagree with the third issue philosophically. (Although the manner in which many animals are farmed is horrid.) But animal rights is a much more murky issue and I'll leave it alone for now.

The second premise is accurate; the livestock sector accounts for 18% of GHG emissions. But saying just this misses some nuance within the meat industry. Beef and pork are not equal to poultry, some fish, and other sources of protein relative to GHG emissions. According to one study (page 6), poultry and milk are three times more energy efficient (in carbon emissions) than beef and six times more than pork. Herring is seventeen times more efficient than beef. And this does not even account for methane emissions, which are 25 times more potent as a GHG. With everything factored in, the beef industry emits 13 times more GHG than the chicken sector.

Lastly, the idea that meat is bad for your health is simply not true. Again, there is a huge difference between eating a diet with a lot of beef and pork and one with a lot of poultry and fish. The main difference here is saturated fat. Beef, pork, chicken, and fish all have relatively high amounts of cholesterol. But cholesterol, by itself, is not a threat to your health. It only becomes the bad stuff that clogs arteries when a person's diet is also high in saturated or trans fat. Most cuts of beef and pork are quite high in saturated fat. Chicken, however, are composed of leaner cuts.

Furthermore, to group fish in with either of these is absurd. Any fish that is high in fat is composed of very healthful Omega-3 fatty acids, specifically docosahexaenoic acid. Far from being damaging to health, a person is more likely to have a healthy cardiovascular system by eating fish, when compared to a diet without it.

The other nutritional component here is the utility of protein. The argument from a climate perspective is that more protein is not linked to better health. Again, a falsehood. Protein, as a building block in the body, may have diminishing returns, but when compared to the common alternatives for vegetarians, then the importance of protein becomes clear.

If someone is not eating protein as a source of calories, then they must be those calories from either carbohydrates or fat. Since carbohydrates are the cheapest to produce (e.g. grains, rice, sugars), this will be the most likely food choice. But these are also the foods that will raise blood sugar in high consumption. Therefore, these are the most likely to cause diabetes in people. Protein, on the other hand, has negligible effects on blood sugar. So a diet high in protein is less likely to raise blood sugar than one high in carbohydrates.

(Carbohydrates, of course, have an important role to play as well. Top among these are fiber and the many vitamins/minerals/antioxidants associated with carbohydrate foods. My point is simply that anything can be overdone.)

Rather than educating the public on the above nutritional differences, many in the climate movement generalize all meat together, using studies that also do not differentiate types of meat.

The upshot: beef and pork farming emits a lot of GHG. At the policy level, governments need to begin taxing or capping GHG emissions in order to reduce the most polluting meat sources. Furthermore, public money needs to be pumped into a solution that would make this whole issue null and void: in vitro meat. Until that happens, we all need to diversify our sources of protein, eating less of it from meat in our daily diet. Dairy, whey protein powder, soy, and poultry are some of the least energy intensive choices.

I am a strong supporter of policies and behavior that will halt climate change. That is why it bothers me when falsehoods are perpetuated by others with a common interest. Campaigns for change are a necessary part of human progress, but not if they are driven by dishonesty.


  1. From a former-vegan (who now makes more specific decisions about food), thanks so much for an insightful look at this. Just a couple points to add:

    1. There are problems with meat consumption beyond risks to human health and climate change. Cattle graze on our public lands, in many cases decreasing biodiversity of the plant, wildlife, and aquatic communities, spreading invasive weeds, and drastically altering habitats (thereby promoting extinctions). They also use vast amounts of arable land that could either be producing food directly for humans, or not producing food at all (thus providing wildlife habitat).

    2. Fish is good for you, but choose wisely. Only some fish have the valuable fatty acids. Many aquacultural practices are terrible for the planet. Many types of fish and fisheries in the world are on the brink of collapse. That doesn't just mean less food for us (and especially for impoverished people living on the developing world's coastlines), it means driving many cetaceans back to the brink of extinction, and generally destroying all sorts of important links in the oceanic food web.

    3. One study looked at the resources required per pound of protein in a number of different foods. Chicken is more planetarily friendly than dairy products. My only quibble with the chicken industry is the waste (of so many "non-edible" parts), and the hormones, chemicals, and cruelty of industrially-kept chickens.

    4. Another important factor to consider is how workers related to these industries are treated. Look at the statistics on death and dismemberment for people who work in slaughterhouses. It's not just an inherently dangerous job. The policies that promote artificially inexpensive meat in this country also promote the hiring of people who can be poorly (illegally) treated and won't fight back.

    5. Yes, I said "artifically cheap." Most of our food is. This is the result of a lot of government policies that were well intentioned but, many years later, have left mny of us obese and diabetic, in addition to other problems. The only reason your local organic farmer at the market can charge as LITTLE as $3/lb for tomatoes is that she is making up for a 25% loss every year with unpaid labor and additional income. The U.S. spends proportionately far less of its income on food than most any other country. Change some of these policies and we change the way we eat, hopefully focusing on quality over quantity.

    6. Some other good proteins that you failed to mention: all sorts of legumes (nuts, lentils), seeds of all sorts (sesame, flax), shellfish (generally good aquacultural practices here, though one must be careful about where they're sited, e.g. mangroves destroyed to farm shrimp), grains (especially when consuming the glutinous portion such as "seitan"), even some vegetables (spinach has 13g per cooked cup). Careful vegeterians do not substitute carbs and fat for protein. Rather, they use alternative sources of protein.

  2. A very thoughtful set of points, thank you. I will take them in kind:

    1. I agree. But this is precisely why I argue for singling out beef (and pork, which is also a huge polluter) as the culprit. Further, these two industries are the most savage relative to factory farming, so significantly reducing them would reduce the unnecessary suffering.

    2. I did not directly talk about the depletion of fish. Fish should certainly not become the *sole* replacement for beef/pork in the diet, and I did not want to make it seem this way. Fish only needs to be consumed in small amounts for the DHA benefits, anyway. Chicken and dairy are less costly routes of protein, otherwise.

    3. It seems like there could be useful ways to reuse chicken parts. (Possibly compost to grow vegetation.) But I agree that all waste should be reduced -- and this goes for all industries and behaviors.

    4. Very interesting point on the labor, but I am inclined to think that the same people who are willing to work in these jobs (assuming they are not forced to do so) would be willing to work in equally undesirable -- from our privileged perspectives -- positions. Labor rights is a larger issue, though, and I do not think that livestock industry necessitates labor abuse. Which brings me to...

    5. I am all for imposing the real price of the costs of meat. Indeed, as I have written, if we had a tax on GHG's (as we should), then meat of every type would become more expensive -- especially the worst, pork and beef.

    Also, the issue of obesity and diabetes as it relates to food policy correlates much more with overall caloric intake and additive sugars than sources of protein.

    6. I just cannot agree with you here (on the quality of protein). With the exception of shellfish (which I just include under "fish", though perhaps I should not have done so), none of the foods you've mentioned are sources of complete protein. As a former vegan, you know exactly what I am talking about.

    All of these sources must be mixed complimentarily. Firstly, this asked a quite a bit from a general American population who barely pays attention to their diet. Second, even if someone complimented proteins, it is difficult to get the optimal amount of complete protein in the diet. It requires a *lot* more mass (though not necessarily calories) than a diet that has chicken, dairy, and fish (and shellfish!). And this alludes to the issue of "optimal" protein, but I wil leave it to you to decide if you want to open that can of chicke... er... salmo... er... spinach.


  3. Hi Kevin,
    Great and thought-provoking post. You nailed some of my personal nitpicks with arguments for vegetarianism, including the mixed evidence on the health benefits and the potential for technology to ameliorate some of the environmental strikes against meat. (Also, I like your response to the previous comment.) However, I'm surprised that you didn't point out in your article/post what is (in my opinion) the most compelling reason for continuing to eat meat, at least for now: we have no other meaningful alternative for the fates of livestock. If, for instance, everyone suddenly became a vegetarian right this minute, the animals would probably have to be killed anyway. Who would be responsible for their welfare, and how would our society pay for it? We can’t even make sure that our humans all have homes, healthcare, food, etc. Are we prepared to house cows and chickens in shelters? Let pigs roam the streets? As it is, we regularly slaughter cats and dogs, animals we culturally adore. Even PETA is a proponent (if begrudgingly) of correctly-performed euthanasia as a "compassionate" act for an animal that is, for lack of resources, doomed to languish in a shelter or in pain.
    I am not a vegetarian, but I admire the veggie ethos of valuing life, and my carnivorous tendencies are mild. So I'm a fairly prime candidate for conversion to vegetarianism. But when I pose the fate-of-the-animals question to ethical vegans who otherwise believe that animals have a right to life, I often get a shrug. Any thoughts?

  4. The bad news: There are no firm rules, only informed choices.

    The good news: This is the "Information Age!" Informed choices are getting easier to make every day.

    The bad news: With increasing access to information, we have increasing responsibility to probe the quality and applicability of that information. Unfortunately, few Americans are getting a good enough education to enable them to do this.

    The good news: We can all teach ourselves to be good consumers of information AND food.

  5. I think you're almost entirely right on. A couple falsehoods that you seem to adhere to:

    1. "...none of the foods you've mentioned are sources of complete protein...All of these sources must be mixed complimentarily." Here are just a few of the vegan proteins that are complete: quinoa, soy, buckwheat, spirulina, amaranth, brewer's yeast, hemp. Many of these are not common in the American diet, but they're all widely available in major cities. Besides, combining rice and beans is not rocket science.

    2. "...even if someone complimented proteins, it is difficult to get the optimal amount of complete protein in the diet. It requires a *lot* more mass (though not necessarily calories) than a diet that has chicken, dairy, and fish (and shellfish!)." The approximate Recommended Daily Allowance of protein is only 47 grams for women and 54 grams for men. I can get more than this from 3oz of seitan, 1 veggie dog, 2 cups of quinoa and beans, and 1 cup of spinach.

    I'm certainly not advocating that we all go vegan. I'm just saying that we could all get much more of our food (including protein) from vegetable sources, if we chose to. Making that choice could have benefits for our health and our planet.

  6. Elizabeth: the issue you raise is an interesting one. It certainly seems like a problem, though I could foresee a counterargument like this: if livestock farming was phased out over a period of years rather than suddenly cut-off, then "stray" animals would not be problematic. But perhaps there is a weakness in this counterargument that I'm not seeing.

    Thanks for the comments.

  7. "Anonymous" (you really ought to post *some* sort of distinct name!), thanks for the thoughts. My responses:

    1. The quality of plant sources, strictly speaking, is still inferior. Branch chain amino acids (the four most important) are significantly lower in plant sources. Although I would suggest that you look in BCAAs, let's move ahead. You make a good point in that most of those plant sources *do* have at-or-near complete protein profiles. But let's look at quinoa, for example: to obtain the 27g of protein found in one 3oz. chicken breast, a person would have to consume over *3 cups* of cooked quinao! The chicken breast would contain about 140 calories; the quinao would supply a person about 700 calories! So in order to obtain the same amount of protein, a person ends up having to consume a tremendous amount of food mass and calories. Consider even the list you provided: "3oz of seitan, 1 veggie dog, 2 cups of quinoa and beans, and 1 cup of spinach." This takes planning that the average person (particularly American) will probably not do. (To be fair, this assumes a veggie-only diet.)

    This all brings us to the next point of contention...

    2. This is a very weak point in the argument. To assume that the RDA is sufficient is absurd. (This is not an attack on you, just expressed frustration with the USDA's slow speed of adapting to better science.) There is a primary problem with the studies that have resulted in the RDA: the nitrogen retention tests were done on totally sedentary subjects. In other words, the RDA amount (which is technically .8 g of protein per kilogram of body weight) is meant for people who are doing little to no movement throughout the day.

    Since this describes few people (even people who do not intentionally exercise as they should be), we need to use more appropriate research. One meta-analysis cites eight studies that show the RDA might be anywhere from 1.4-2.2 g/kg. (See the section beginning with "In summary protein requirements appear to be elevated..." in the following link.)

    (Also, there is a good overview of the importance of BCAAs in the section below that one.) That study also looks at athletes, which makes up for the inactivity issue.

    But at the same time, there are plenty of other studies that show a clear correlation between high protein intake and positive health indicators in non-athlete subjects. (Put another way, they show the insufficiency of the current RDA.)



    This study shows that the RDA results in bone loss in healthy women:

    The above studies (and many others, if you still are not convinced), show the problems with the current RDA. That said, the problem becomes establishing a new sensible RDA. Some of the above links have some recommendations, as do the following:

    The latter study recommends 1.5 g/kg for optimal health in the elderly. So this seems like a conservative, if imperfect, target for the general population. Based on the first link, the more active someone is, though, the more protein they would require.

    (Continued below)

  8. So now, using a baseline of 1.5 g/kg, a strict vegetarian is left in a difficult position. A 166lb (75kg) relatively inactive person would need to consume 112g of protein in a day. This is 14 cups of quinoa, which is 3108 calories. So now you're overeating. True, a vegetarian is not only going to be eating quinoa, but every plant alternative for protein isn't much better.

    The problem with most plant sources of protein is that their percent of calories from protein is low. Quinoa, amaranth, and buckwheat derive 15% of calories from protein. Extra firm tofu takes 43%. Chicken breast, by comparison, derives 78%. And 1% fat cottage cheese has 67% calories from protein.

    Even using tofu, that 165lb person would have to eat 2.5 pounds of firm tofu every day -- a hefty feat. (And this is assuming the person does little activity, which is not a great assumption for optimal health.)

    Enough hypotheticals. You get the point. To meet the requirements for optimal protein intake (without tremendous daily planning or effort), it is necessary to incorporate some forms of animal food products into the diet. But as I argued in the original blog post and my FP article, the sources of animal products should be those that do the most benefit for human health and the least damage to the environment -- like dairy, chicken, fish, and shellfish.

    Maybe I should have just written this whole response as a new post!

  9. cancer of the colon as well as other cancers have been linked to eating big quantities of meat. Animal proteins make the kidneys work much harder to digest than other proteins which is why I turned vegetarian. I was diagnosed with IgA nephropathy (chronic kidney disease) 2 years ago. I would like to make the vegan transition one day. Even my husband and 6 year old daughter went veggie to help support me. Bottom line, our bodies are not built for these animal products if we are to comsume them, moderation is key. I can see the need to sympathize with animals their treated horribly cruel. I don't know when I think about a calf being taken from its mother right after birth and raised for veal being terrified and desperatly wanting its mother all while purposely being fed a low iron diet to make it anemic so its skin remains pink and then off to slaughter it goes. Sorry but I can't help but feel heartbroken. You are right though, if everyone became vegan or vegitarian the livestock would have to be killed off and they will by wolves, cayotes, mountain lyons ect. Ect. Everything has its purpose in life that's why when one species is extinct it usually disrupts some other form of life. P.s. I'm not the previous poster who posted under anonymous.