Lettuce and Bacon and the Environment: Some Thoughts for Vegan Activists

Lettuce and Bacon and the Environment: Some Thoughts for Vegan Activists

By | 2015-12-18T06:44:40+00:00 December 18th, 2015|Tags: , |20 Comments

lettuce bacon


Is lettuce really worse for the environment than bacon? That’s what the latest headlines say, based on findings from new research at Carnegie Mellon University in Pittsburgh.

Allegedly, lettuce produces more greenhouse gas (GHG) emissions than unhealthy foods like bacon. The media have gleefully proclaimed, based on this study, that vegetarian diets are bad for the environment.

But that’s not what the study showed. It’s not even what the study looked at. It looked at what happens when people eating a usual American diet shift towards a healthier eating pattern as defined by the USDA. And what happens is that the environmental benefits of eating less red meat are offset by the greater GHG emissions associated with dairy, seafood, fruits and vegetables—all foods recommended as part of this healthier eating pattern.

The researchers said this:

 Dairy, by far, has the greatest impact on increased GHG emissions because it has the third highest emissions intensity value, which is then compounded by USDA recommendations for substantial increases in dairy. Fish/seafood is the second most driving force behind increased GHG emissions. While recommended intake of fish/seafood is low relative to fruits and vegetables, the emission intensity of fish/seafood is significantly higher.”

In short, replacing red meat with dairy and fish is not good for the environment. The study didn’t look at what happens if people replace red meat with grains, beans and soyfoods. Nor did it look at vegetarian diets. The investigators did, however, acknowledge that other research shows that adopting a vegetarian diet reduces water footprint and GHG emissions. In fact, they noted that a vegetarian diet is more effective than usual healthy eating patterns in this regard.

So what about the lettuce versus bacon comparison? It’s pointless. Even if lettuce is associated with greater GHG emissions than bacon on a per calorie basis, this isn’t relevant to vegetarian diets or any other kind of diet since nobody is packing in calories from lettuce. You would have to eat 16 cups of iceberg lettuce to match the number of calories in three strips of bacon.

But there is a little bit of a problem here for animal activists. Because vegans sometimes play the exact same game. How often have you seen infographics and memes showing that broccoli, spinach and even parsley are more protein dense on a caloric basis than beef?

Parsley? Seriously? Yes, it has a fair amount of protein per calorie, but you’d need to eat 16 cups of raw chopped parsley or 8 cups of cooked broccoli to get the amount of protein in three ounces of steak. That doesn’t sound like a very useful comparison to me. In fact, it sounds about as useful as comparing GHG emissions between lettuce and bacon.

And while we might rightfully complain about the way in which the media misrepresented findings from this study, it’s not as though vegans never do the same thing. Just last month my Facebook feed was packed with memes and links suggesting that processed meats are as carcinogenic as cigarettes, an assertion that misrepresented a report from the World Health Organization.

I know that many vegans are not doing this intentionally. It’s hard to evaluate all of the health information that flies around the internet, and to determine what is accurate and what isn’t. But in the face of that difficulty, we do need to use some care in how and what we share regarding vegan diet and health. Because vegans cannot challenge biased interpretations and misinterpretations of research or irrational conclusions about nutrition if we do the same things ourselves.

We can’t speak out against bad science that hurts the image of veganism if we use bad science to promote veganism. We need to approach the research on diet and health—and on the environment—with the utmost integrity. Then, when the media and others make ludicrous claims that hurt the image of veganism, we can respond from a position of strength.


  1. Russell December 18, 2015 at 9:42 am - Reply

    You are the best!

    • Ginny Messina December 18, 2015 at 2:21 pm - Reply

      Thanks, Russell!

  2. Matt December 18, 2015 at 10:31 am - Reply

    My biggest fear is that whenever we use health or environmental arguments, there will be some meme out there than veganism is unhealthy, chicken is healthy, lettuce is worse than bacon, chicken is better than tofu, etc.
    Here is the key point: *It doesn’t matter what is really true.* People will believe *what they want to believe,* and there will always be people willing to tell them what they want to hear.
    If we divorce the case for compassionate eating from ethics, we will *always* be left with a he-said / she-said “debate.”

    • David Weinman December 18, 2015 at 11:57 am - Reply

      I too dislike the “vegan for health or environment” claims. That is why I always say I’m vegan for the animals and whole-foods plant-based for health and environment. It always gives people pause since many people automatically think I don’t eat animals products for my health and it can lead to some good discussions about the exploitation of the animals people eat and use.

      • Ginny Messina December 18, 2015 at 2:22 pm - Reply

        Matt and David, I definitely agree as you know! Stick with the ethics and you never have to defend your stance against new evidence.

        • Mike December 19, 2015 at 10:58 am - Reply

          Really? Part of making the case for veganism is showing that animal products are unnecessary. Yet, if research were to show that veganism is detrimental, a key aspect of the ethical argument would be undermined.
          Some may think a vegan lifestyle is morally required even if bad for health, but I do not accept that nor will most people.

          • Colin December 19, 2015 at 5:09 pm

            We should be using the health or environmental argument ONLY as proof of the claim that Veganism is not harmful, NOT as the reason for going Vegan, since it’s not literally possible to “go Vegan for health” or “go Vegan for the environment.” Veganism is a moral stance:


  3. Nichole December 18, 2015 at 11:14 am - Reply

    Ah, thank you for this! Not just the response to the lettuce vs bacon shenanigans, but the reminder that making these kinds of comparisons is useless and misleading in both directions.

    • Ginny Messina December 18, 2015 at 2:23 pm - Reply

      Thanks, Nichole!

  4. Jan Steven December 18, 2015 at 11:46 am - Reply

    Thank you.

    • Ginny Messina December 18, 2015 at 2:23 pm - Reply

      Thank you as always, Jan. <3

  5. Nancy December 18, 2015 at 12:49 pm - Reply

    regardless of the shabby and misinterpreted “research” the author used to write this article which lacks common sense, we need to know that MORE crops are grown to feed animals than are grown to feed people. If people are concerned about the environmental destruction of growing lettuce or other crops, they really need to stop eating animals so we can grow exponentially less crops. Animals not only emit greenhouse gases when alive, their manure is very environmentally-destructive. NO, the manure cannot just be used to grow crops because of the way animals are raised and fed, and there’s also just way too much of it. This author needs to watch Cowspiracy and Racing Extinction or please find another line of work.

    • Ginny Messina December 18, 2015 at 2:27 pm - Reply

      Nancy, I’m kind of wondering if you actually read this post. The research wasn’t “shabby” (have you read the study that you can say this?) and it didn’t negate findings about the harmful effects of animal farming. It merely said that trading in red meat for fish and dairy isn’t helpful. Both the research and my post noted the benefits of vegetarian diets for the environment.

  6. Kezia December 18, 2015 at 6:46 pm - Reply

    As usual you said it better than I could. But I did have a similar complaint about the health “infographics” vegans share, here: http://thethinkingvegan.com/rant/warning-this-post-contains-infographic-images/

  7. Dave Edwards December 19, 2015 at 8:07 am - Reply

    Superbly written piece, thank you.

    I got so fed up with seeing the broccoli protein memes that I closed my Facebook account.

    Heaven help new vegans with the nonsense out there, your writing should be mandatory.

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  11. Alex June 6, 2016 at 5:33 pm - Reply

    Of course “per calorie” is relevant. Indeed it’s the ONLY useful metric for comparing relative impact of diets. We are generally not limited by serving size, not by weight, not by volume, not by any other “nutrient” except calories.

    If a meater eats 3 oz steak and the vegan eats only one cup of parsely, then what else is she eating at that meal? It’s only logical to measure an entire day’s consumption when comparing GHG emissions, maybe 2000 kcal, irrespective of serving sizes.

    7143 g iceburg 1000 kcal (sans B3, D, B12, I Se) 64.3 g protein
    214 g bacon pk 1000 kcal (sans B2, B5, folate, A, C, E, D, K, Ca Cu Fe I Mg Mn K Zn) 72.5 g protein
    2941 g broccoli 1000 kcal (sans D, B12, I Se) 83 g protein
    2778 g parsley 1000 kcal (sans D, B12, I Se) 83 g protein
    4348 g spinach 1000 kcal (sans B5, D, B12, I Se) 124 g protein
    625 g beef stk 1000 kcal (sans B1, B5, folate, A, C, E, D, K, Ca Cu I Mg Mn K) 187 g protein

    • Sel June 14, 2016 at 5:07 am - Reply

      The vegan would be primarily eating any variety of beans, lentils or tofu/soy which are far more nutrient rich then the greens you mention. Therefore, rather than eating dozens of portions of parsley (for instance) to replace meat, a vegan will eat 2-3 normal sized portions of beans, lentils or soy/tofu to gain the sufficient nutrients. So in terms of environmental impact, it’s more pertinent to look at the effects of legumes, tofu and nuts, since those are the foods which form the core of the vegan diet. And while vegans are not absolved from detrimentally affecting the environment, animal products have a much greater environmental impact – there are many papers on this and recently I saw a good documentary which explores this; Michael Mosley’s (not a vegan) the Truth about Meat.

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