Body of Wonder Podcast

Episode #23 Embracing a Sustainable Diet with Brent Kim, MHS

Our daily food choices can have a lasting impact not only on our personal health but also on the health of our planet. The worldwide population is expected to reach 10 billion by 2050 and research shows that human dietary patterns may have a staggering effect on climate change.

Today we’re joined by Brent Kim, MHS a global disease epidemiologist and researcher at the Center for a Livable Future at Johns Hopkins School of Public Health. Kim has published works on sustainable diets, climate change, industrial food, animal production, soil safety, and urban food systems.

As we witness dramatic consequences of climate change, it’s clear that we must work together to lower greenhouse gas emissions. Kim outlines the criteria critical to a sustainable diet and how they play a role in climate change. He describes factors accelerating global emissions and the actions we must take now to avoid future disasters.

In this episode, Kim explains why meat consumption is a complex topic, and Dr. Maizes and Dr. Weil discuss motivations for adopting and maintaining vegetarian and vegan diets. The discussion includes meat alternatives, like plant-based-processed burgers and lab-grown meat, and addresses their health implications. Dr. Weil suggests lesser-known, low-food chain organisms like algae and insects as new sources of protein. All agree that integrative medicine and sustainability are founded on systems-based thinking, leading to the question, “what other societal changes are needed to meet the challenges of climate change?”


Please note, the show will not advise, diagnose, or treat medical conditions. Always seek the advice of your physician or healthcare provider for questions regarding your health.


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Guest Bio

Brent Kim

Brent earned his Master’s in Global Disease Epidemiology and Control from the Johns Hopkins Bloomberg School of Public Health, where he serves as a Program Officer at the Center for a Livable Future. Since joining the Center in 2008, his work has spanned farm to fork, with published works on industrial food animal production, soil contamination, urban agriculture, food and agricultural policy, and the role of diet in mitigating climate change. As a former digital artist and high school educator, Brent has never lost his love of teaching and visual communication and continues to translate the science to students, journalists, policymakers, and other key audiences.

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Dr. Maizes: Hi, Andy

Dr. Weil: Hi, Victoria.

Dr. Maizes: We talk a lot about food and nutrition and the implications for health and integrative medicine. It turns out what we eat also has huge implications for the health of our planet.

Dr. Weil: Yes. And I think this is an area that many people are uninformed about how dietary choices have very significant environmental implications. So I'm looking forward to this conversation.

Dr. Maizes: That's exactly what our guests, Brent Kim specializes in his research at Johns Hopkins is all about the food choices we make and how they affect climate change, greenhouse gases, et cetera.

Intro Music

Victoria Maizes: Brent Kim earned his master’s in global disease epidemiology from the Johns Hopkins School of Public Health, where he now serves as a researcher at the Center for a Livable Future. Since joining the Center in 2008, Brent has spanned from farm to fork with published works on sustainable diets, climate change, industrial food, animal production, soil safety, and urban food systems. His work has been featured in Popular Science, the Guardian, the Huffington Post, NPR, and Newsweek. Welcome Brett.

Brent Kim: Thank you. It's my pleasure. And a delight to be here and to see you both.

Victoria Maizes: We're so happy to have you on the podcast. I want to start with the concept of a sustainable diet. What kind of criteria do you use to define that diet?

Brent Kim: Right. Yeah, you know, every company from Amazon to Monsanto says they have a commitment to sustainability now. So I think it's important and worth asking when we're talking about sustainable diets, what does that actually mean in practice. And so I've adopted a set of what I feel are holistic criteria from the United Nations Food and Agriculture Organization and those criteria are first that for a diet to be sustainable, it must be ecologically sound. And that's usually not a surprise to most people because when we think about sustainability, usually the first thing they think about is the environment. But you know, I think that term environment itself is quite broad.

I often hear questions like, “well, which foods are good for the environment?” and it's such a, it's such a vague kind of open-ended question, right? Cause the environment can mean a lot of different things. So when we're thinking about a sustainable diet, you know, we're not only thinking about climate change in a silo.

For example, we're thinking about climate soil quality, conserving fresh water, water quality biodiversity, how we're, how we use our land. Second for a diet to be sustainable it also has to be nutritionally viable. We could have the most environmentally friendly diet in the world, but if it doesn't meet the dietary nutritional needs of that population I think you could argue that that diet is not going to go very far.

Third, you make a case that the diet must also be culturally acceptable. So we've done some work and I have some wonderful colleagues who do work in Indonesia. We have some research underway there. And that's a great example where we have a plant-based protein like tempeh high protein, low greenhouse gas footprint, protein dense fermented soy food, and it originated in Indonesia, so something like tempeh would be a natural fit as a culturally appropriate protein source for a sustainable diet in that particular context. Fourth and fifth, for a diet to be sustainable it has to be affordable and it has to be physically accessible we can't prescribe a diet to someone with foods that they can't get to either because their grocery store doesn't sell those foods or they can't even get to a grocery store because there's no public transit. And, you know, that's a big focus of the work of my colleagues at the Center for Livable Future in Baltimore city is identifying what we call healthy food priority areas, where there are neighborhoods with limited access to fruits and vegetables. So affordability and accessibility are key.

And last but not least, John Eichert is one of the leading thinkers on sustainable agriculture and he makes the case for a food system to be sustainable it's not sustainable if it serves some people, but not others. So the last criteria I'd like to include is that it also has to be socially just.

So we take all of these things together and we have a holistic idea of what a sustainable diet might mean.

Andrew Weil: So Brent, how does the, the standard North American diet measure up against these criteria? Where does it fail?

Brent Kim: Yeah, I mean, we're certainly not scoring so well on the ecologically sound criteria, which is a big focus of my work.

And I think that's in stark contrast to low-income countries with a high prevalence of malnutrition where, you know, those are countries where the animal product intake is already very low in a modest increase in animal foods could help stave off lifelong burdens from stunting and malnutrition. So actually some of our recent research found that, you know, in order for many of the low-income populations in the world to meet their nutrition needs, they will actually have to increase their climate change footprint a little bit, with a modest increase in animal foods in order to attain the recommendations for a healthy diet in those places.

Which means, conversely, that in order for us to meet climate change mitigation targets, which we can talk about more in a minute, high-income countries, high meat consuming countries like the United States need to scale back even more to offset the increase in those other countries.

Victoria Maizes: So you've really introduced the great complexity of this topic.

And we're going to unpack it over the course of this conversation, but one of the things you brought up is climate change and greenhouse gases. And I think that people may not be aware of the extent to which the way we raise animals for food contributes to greenhouse gases. Livestock production is estimated to create 14.5% percent of global greenhouse gas emissions. And all of our transportation is a little less than that. So I'm not sure everyone's aware of how central this is to reducing greenhouse gases.

Brent Kim: Yeah. That's a great point. And, pulling the lens back, if there's, if there's one thing that I'd want our listeners to take away it's this so most, most folks are aware global leaders and scientists have agreed that we have to keep global average temperature rise at or below 2 degrees Celsius relative to the pre-industrial era. In other words, we don't want the planet to get too hot because that's tied to a whole host of catastrophic downstream effects. So, 2 degrees is sort of this ceiling that we have to stay below. And ideally we would cap it at 1.5 degrees Celsius it's even lower.

Now in 2015, we reviewed the evidence and found that numerous studies have the same message if global meat and dairy intake continues to rise as projected, by the year 2050, the greenhouse gas emissions from agriculture alone will eat up pun intending. I don't know, it's not very funny, I don't want to make a pun out of it, will eat up almost the entire greenhouse gas emissions budget with no room for the greenhouse gas emissions, from energy industry, transportation and all of the other sectors.

So what that means is, you know, almost everything right we can switch to renewable energy, cut back on flying, ride our bikes, drive electric cars, take public transit. And just to be clear, these are all things that we do need to be doing. But if we don't also address the greenhouse gas emissions from agriculture, [we will very likely overshoot the 1.5 and 2 degree targets for warming.

Andrew Weil: When you talk about greenhouse gas emissions from agriculture what is that coming from? Is it, what is it coming from other than the raising of animals?

Brent Kim: Yeah, so we can, we can break that down. You were right on global estimates put raising animals as a whole together at about 15% of global anthropogenic or human caused greenhouse gas emissions. And that's about on par with the transportation sector. Now that green house gas emissions of agriculture as a whole most the vast majority of those greenhouse gases are attributable to raising animals and those greenhouse gas emissions from animals that that 15% of global emissions is attributed to the largest shares methane from enteric fermentation, which is a digestive process, which is unique to ruminant animals, or animals with rumen, multiple stomachs we're talking about cows and bison. That's about 40% of those emissions come from a ruminant irritation, which is a scientific term for belching.

So it comes up to the front side. Some people think it comes up the back, but most of it comes up the front of the animal. Another quarter of those greenhouse gas emissions are from methane and nitrous oxide, both potent greenhouse gases from decomposing manure. So, whenever we have decomposing organic matter and any anaerobic conditions in the absence of oxygen releases methane the potent greenhouse gas we have another quarter of those emissions from growing feed props for the animals.

And then about 10% are from actually clearing the Amazon. So you know, trees, soil, plants, all of these are what we call carbon sinks or store houses that hang on to carbon that would otherwise be released into the atmosphere and contribute to climate change. So, when we're massively clearing down the Amazon rainforest massive ecological crisis, we're releasing all of that stored carbon back into the atmosphere. You know, these are all global statistics. The actual breakdown emissions are going to vary by country. So a lot of people in the US will ask me, oh gosh, how is my beef contributing to Amazon deforestation in the US we don't actually import a lot of beef from Brazil. So we're not directly contributing to that problem through our consumption. It doesn't mean it's not a problem. It's a huge problem. And the meat that we in the US contributes to climate change in other ways you know, this is just a caveat. Sometimes when you break things down country by country, this story is a little bit different.

All that being said, livestock major contributor to climate change.


Andrew Weil: So, Brent, I've been advising people for many years to reduce consumption of animal products and beef in particular for a variety of reasons, mostly health reasons, but more recently I've been urging them to do so for environmental concerns as well.

I'm very interested in, in lab grown meat. Which is going to be available to us soon. I'm wondering how you feel about that since this would be a way for people who love meat, perhaps to satisfy their appetite without contributing as much to the environmental degradation.

Brent Kim: Yeah, it's a great question right? It's certainly a technology, it's on the horizon, right. You know, we had a paper on this recently on a meat alternatives, which we can sort of broadly break down into two categories. Plant-based meat alternatives so we have our Impossible Burger and our Beyond Burger made from food like gluten and soy.

And then we have cellular meat or, or lab grown meat, which is not yet commercially available, but it's on its way soon. And I think, you know, we tried to look at it from a holistic public health perspective. We can look at. In a lot of different ways. One there's the climate change perspective in terms of the climate change impact of cellular meats, I think there's a lot, we don't know yet.

Most of the studies that have been done are fairly speculative. That being said. They are estimating that it could have potentially assist up substantial greenhouse gas footprint. That's a little bit different than beef for example, right? Most of the emissions are coming from methane when we're producing cellular meat.

Most of the greenhouse gas emissions are in the form of carbon dioxide from the heavy use of energy, right? So it's taking a toll on the energy grid and that's, what's producing the greenhouse gas emissions. So not all greenhouse gases are created equal. If that technology does scale up one advantage is that if we do shift our energy grid, off of coal and fossil fuels onto renewables, then that would mitigate the climate change impact of producing cellular meats because if our energy, energy grid is running on wind and solar.

It won't matter as much that it's using a lot of energy. So that's, that's sort of the climate angle. As far as health, well, actually, let me bounce that back to you. What are your thoughts from a holistic nutrition  or the health implications of cellular meat and the same, same question for Beyond an Impossible meat?

Andrew Weil: I don't know enough, frankly, to give an answer to that from what I've seen it certainly looks as if it would be acceptable, nutritionally might be good. I'm lab grown fish seems to be a near reality as well. I read that a sushi restaurant in San Francisco is about to open that will serve only cellular fish.

That would be great for taking the pressure off the oceans. So from that point of view, that would be great. But I need to, I need more information about the nutritional content and Victoria, you can say something about the, the burgers that are out there.

Andrew Weil:  I have concerns about them.

Victoria Maizes: Yeah. I think first in terms of the cell-based potentially there would be a lot less antibiotics needed to be used because I would think cells won't get sick the way animals get sick. And so that might help us in terms of antibiotic resistance and make it safer for the people also who work in meat production, the plant-based, you and I have talked about this, many people consider it an ultra-processed food, which we're always recommending that people avoid.

So when you look at the ingredients of these new burgers, which on, on some level sound amazing you see lots of additives and lots of ingredients that are put there to try to replicate either the sensation or the taste of meat, and in general we're nervous about ultra-processed foods we know that they can wreak havoc on the microbiome and potentially do all sorts of other damage.

Andrew Weil: I think there's the possibility of producing high quality protein foods from the cultivation of fungi and algae. And this could be done in a way that produces acceptable foods that don't have unhealthy additives in them.

And I think that's all on the horizon as well.

Victoria Maizes: Yeah, that's interesting. Some years ago there was a product on the market called corn, which was a new micro protein that humans had never eaten before. And I think it's still on the market, although I'm not sure some people have reactions to it and it gets to regulation, you know, who regulates a new food protein that's [00:16:00] unknown to humanity.

Brent Kim: Right, right. A lot of, a lot of unknowns about how that's going to work. Is there a species or cultivar of fungi that you feel would be a particularly good candidate for this?

Andrew Weil: I think there's a lot out there. You know, there, there many of the food mushrooms, edible mushrooms that the mycelium can be cultivated in quantity and converted into high quality proteins.

So I think there's a lot of candidates out there.

Brent Kim: I'd be excited to try it. And I mean, you raise a lot of good points and questions about I see all this research on the relative long-term health benefits of a whole food plant-based diet. And I'd like to hear your thoughts, at least from my understanding it's, it's not clear how the research will play out for folks who maybe adopt a plant-based diet but what if a lot of their plant proteins are coming from these highly processed burgers? I'm thinking of some of them are very high in saturated, fat from coconut oil and so on it's just not clear to me how the evidence is going to play out when we say benefits of a plant-based diet, what does that mean if your plant-based diet is Beyond Burgers?

Andrew Weil: Yeah. What about eating lower on the food chain, I've heard you talk about this, especially eating more shellfish for example, and possibly insects.

Brent Kim: There's evidence to suggest that a low food chain diet could be a very promising and sustainable way to go. Meat tends to be the elephant in the room when we're talking about food and climate change, and it gets a pretty bad rap, but I think it's important to take a more nuanced look at different meats. Not all meats are created equal. In particular one of our reviews of the evidence found that there are certain types of meat that are quite low in terms of their greenhouse gas and their fresh water footprint, and those include what we dub low food chain meats which include small fish at the bottom of the food chain. So your sardines and anchovies and there tends to be a little bit less concerned for over fishing, those particular species particularly at the moment. That's true. And at least relative to some of the larger species where you have to farm the smaller fish to process into fish meal to feed to the bigger fish.

I should say, relatively speaking up to it at the moment, is it an important caveat. Oysters are another great example. So bivalve mollusks you know, here's a species that when you, when you're farming and you're actually improving water quality, as opposed to a lot of the other terrestrial animal foods that can worsen water quality and insects.

I mean, mealworms and crickets I think are absolutely a sustainable protein of the future. So I think you know, what we found was that a diet that where your, your proteins are predominantly plant-based, but then you supplement with some proteins from these three groups of low food chain animal foods, you can get a diet with a greenhouse gas profile that pretty low, in fact, almost as low as a completely plant-based diet. And then even in some cases be able to meet all your B12 so you don't even need to necessarily supplement.

Victoria Maizes: So a few years ago at our nutrition conference, Andy brought up the possibility insects as a protein source. And actually at one of our tasting sessions we had insects that people could taste and most people were curious, crunchy, interesting, but I'm not aware of insects making a lot of products. Moving into the larger food system in the US what parts of the world really depend on, on insects as a protein source? And how close do you think we are to adopting this in the United States?

Brent Kim: Yeah, that's a great question. I'm not well versed on where those are popularly eaten, but I can certainly say that I think it's, you know, it's a social norm. It's a, it's a cultural view of eating something that. We happen to be uncomfortable with the idea of the United States, but there are plenty of other parts of the world where, you know, folks don't think twice about eating a meal worm or a cricket. We recently had a population boom of cicadas here on the east coast. It was funny a colleague was actually referring to them as “tree shrimp” as kind of this land-sea shrimp. I mean, they're just so abundant. You couldn't walk outside without getting hit in the face by, you know, 20 of them.

Victoria Maizes:  I heard that on a podcast and the person who was harvesting them for food talked about that the younger ones tasted better than the older ones.

Brent Kim: That's right. Yeah. The trick was to sort of catch the nymph stage after, after they emerged from the ground, but before they molt into the fully grown, I think, I dunno if the taste goes off once they have their hardened exoskeleton.

So yeah. There's like a window when you’re supposed to go out and collect them. So anyway, we'll have to wait at least another decade before we can experiment with that idea. But.

Victoria Maizes: Well, besides insects, as Andy brought up, not all animal foods have the same impact on greenhouse gases.

Can you talk about the difference between wild fish and farmed fish and poultry? Pork. I mean, it's, it's not all as bad as ruminant animals.

Brent Kim: Yeah, certainly, I'm not an expert on agriculture, but I can say even within moving in animals there's considerable differences and you know, not all beef is created equal.

I can say broadly, whether it's pork, poultry or beef, we have the prevailing industrial model of animal production. Where a single operation can easily house thousands of cattle, tens of thousands of pigs millions, or even tens of millions of laying hens in confined operations.

And these numerous studies, some of them from the Center for Livable Future have documented public health and ecological threats of these models. And you've talked yourself, Victoria, about the risk of, you know, the misuse of antibiotics in these operations the generation and spread of antibiotic resistant, superbugs to workers nearby communities through the food supply chain.

You know, I think it was Margaret Chan from the UN, who said, you know, the world is headed for post antibiotic era in which common infections and minor injuries they've been treatable for decades can once again, kill, right? So not all operations are contributing to this, but many are depleting the effectiveness of lifesaving medicines. You know, we hear from rural communities who maybe have someone who lives in North Carolina and next door to them is a swine operation, you know, 20,000 hogs. And they'll “Gosh, I it's a hot day and I have to have all my windows closed because the odors are just overwhelming. I can't go outside to hang my laundry because the odors are just so strong” and it's more than just a bad smell that can have physical and mental health implications so this is the industrial system. Now, if we were to purely look at this from a climate change perspective and just look at the numbers the industrial model for all the downsides has been extremely effective in reducing the amount of human labor involved and the amount of land involved.

It is efficient in one sense in so far as you know, compared to some more agroecological pasture-based operations, if we really were to nitpick about the numbers, pound for pound, meat from some of these industrial operations might have a it sounds counterintuitive, but it might have a small or greenhouse gas footprint per pound of output.

But then you really have to ask, if we were only thinking about the numbers and only thinking about greenhouse gas emissions in that narrow view, meat from the industrial system might seem favorable from a climate perspective. But when we think more holistically about farmer autonomy, animal welfare, and antibiotic resistance, and air, water climate, the health of rural communities, the health of the health of the workers, right?

From a broader holistic view, regardless of maybe it has a slightly smaller greenhouse gas footprint, a case could be made for public health, that we should be shifting away from this industrial model to the more agroecological alternatives, even if it means, you know, per pound of output, the greenhouse gas emissions might be higher because it's quote unquote, you know, less efficient to produce food in this way.

And now there's another wrinkle that I'm going to add on top of that. And that is within ruminant animals, not all beef is created equal. So we have feedlot finished in industrial beef, and then we have beef that's finished on grass. Even within that grass-finished category, not all grass-finished beef is created equal either because you kept animals that are out grazing continuously out on the grass.

But then there are practices in which the farmers are rotating the animals from paddock to paddock quite frequently. And there are aspects of this practice that actually contribute to soil carbon sequestration. So partly through the trampling action of the animals we're actually taking carbon out of the atmosphere and storing it in organic matter in the soil.

So if you're taking carbon out of the atmosphere using these practices, you're offsetting some of the other greenhouse gas emissions. Now there are some caveats of these benefits. One caveat is thatthis only applies for a very specific approach to raising beef. So when we go to the grocery store, when we picked oh, grass finished beef, I don't think we should just assume that, you know, those producers have necessarily sequestered a lot of carbon. The other caveat is that soil is like a sponge.

So once you've sequestered a certain amount of carbon, the rate at which you're sequestering new carbon and then old carbon is being lost sort of becomes an equilibrium. So the effect sort of has diminishing returns over time. It also depends on, you know, if you're starting from heavily degraded soil, there's a lot more potential to sort of soak up the sun, so to speak.

Whereas if you know, this soil is already pulling a lot of carbon, you might not be able to have that much more. there are some folks who say, “oh, you know, raising beef can save us from climate change or reverse climate change by sequestering carbon.”

And I think that's getting way ahead of the evidence. I don't think there's evidence to support that degree of benefit, but carbon sequestration on these particular agroecological practices can at least significantly reduce the greenhouse gas emissions of beef from grazing animals.

Sorry. I really went on there. I kind of geek out about this stuff, but I'll stop.

Victoria Maizes: How about the raising of chickens?

Brent Kim: From a climate change perspective you know, per unit of output that greenhouse gases are considerably lower.

So if we ranked from largest to smallest, we can go from beef to pork, to chickens. Again, that's purely from the climate change view. So yes, for climate change, it would be preferable to eat chicken versus beef. But again, I think it is helpful to think beyond just the climate change measures, consider more holistically like how those birds are being raised

Victoria Maizes: Yeah, you keep using that wonderful term looking at something holistically. I think also we would call the systems-based thinking, and that's certainly a way in which integrative medicine approaches something. But from, from that perspective, I know that you've written about three specific requirements one is that if we want a livable future, we have to have a plant-forward diet. So that's necessary, not necessarily vegan, but it's heavily dominant with plants. We have to reduce food waste, which we haven't talked about yet. And also we have to use technology. Can you comment a little bit on the food waste and the technology?

Brent Kim: Yeah, certainly. So I think early, we talked methane from decomposing organic matter, which you have when in a manure or liquid manure storage pit from an industrial operation, for example, major source of methane. Similarly, when you have organic matter decomposing in a landfill, what you often find is that that organic matter is compacted beneath tons of other materials. So once again, you have organic material that's in the absence of oxygen. So you have anaerobic decomposition, thus you have a large amount of methane emissions from landfills. In a fact if all of the greenhouse gas emissions from landfills were represented as countries, landfills would be number 2 behind China in terms of their greenhouse gas contributions, if you took all the landfills. I think in terms of bang for our buck for climate change mitigation, number one is plant forward diet. Again, not necessarily exclusively vegan. Number two is reducing food waste.

And number three is technological interventions that either sequester carbon or reduce the greenhouse gas intensity to production. And in fact, in a recent study from Eat-Lancet commission, some of the brightest minds on food systems, they concluded that if we just achieve one of these 3 we will likely not stay within the Earth's ecological boundaries.

The only way to stay with our boundaries for whether it's climate or water quality is to achieve all three. So we have to have the plan for diet. We have to have reductions in food waste. And we have to have the technological interventions if we're going to have a livable future.

Victoria Maizes: Yeah, these are really important. And these are hard facts to hear. And I appreciate the way in which you are elaborating on how complex and, and how critically important it is that we make these changes. Andy you've spent your life helping people make behavior change to be healthier. And here also would be the health of the planet.

What do you think can be done to encourage people to eat a plant forward diet?

Andrew Weil: Well, one thing I've learned is that it's difficult to advise people to make global changes. And when people try to do that, they often don't stick with them. So I found it more useful to suggest a simple steps that people can take and build on.

And I guess my main message to people recently has been to really try to reduce and possibly avoid beef consumption. You know, that would be that one piece of it, I think would be extremely helpful, especially in the US, in north America in general.

Victoria Maizes: Margaret Mead is famously quoted for her saying “It's easier to change a man's religion than his diet.”

Brent Kim: That sounds about right.

Victoria Maizes: Yeah. I have to say my patients who show up in my integrative medicine practice are often quite motivated and are often, really impressed by how dramatically different, meaning better, they feel when they go on an anti-inflammatory diet, which would really limit the amount of beef consumption. I also think as a society we’re creating some interesting strategies like “Meatless Mondays”, or there was a famous food writer who had a Vegan before 5” or something like that. And, you know, he suggested that your breakfast and lunch be vegan and that you enjoy what you wanted for dinner.

And I think Brent, your work has shown that if we were 2/3 vegan, we would make a lot of progress in reducing greenhouse gas emissions.

Brent Kim: That's right. More progress in fact, then eliminating meat entirely, at least under these models and scenarios. And, I'm with you both and that I'm all for gradual reductions.

I'm also in favor of interventions that maybe don't necessarily need to eliminate completely any particular food group. You know, what was interesting when we found with the lacto-ovo-vegetarian diet is a diet in which someone eliminates all meat, but they to compensate they might be increasing their dairy intake.

And dairy also comes from ruminant animals and it does have a significant greenhouse gas profile. So the reason why adopting a lacto-ovo vegetarian diet might not yield as strong of a greenhouse gas reduction is because we're offsetting some of the reductions of eliminating meat by increasing dairy, which is why our evidence suggests that it may be more beneficial for climate change rather than eliminating meat completely to adopt something like Mark Bittman's Vegan Before 6, where you're still eating all the same [00:34:00] foods, but for two of three of those mailers, it could be two out of three years. We had a five or whatever.

You know, you're having to out of free, exclusively plant-based meals. And then for the other one, you eat, whatever it is you would normally eat.

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Brent Kim: I think a lot about the surface idea of gradual reductions. I was talking to a gentleman recently who told me, oh, you know, it's interesting, you do research on plant-based diets and climate change.

But you know, I just couldn't do the vegan diet because I couldn't eat honey. And here, I thought, here's a person who was actually considered open to the idea of dramatically reducing their environmental impact and probably benefiting their health. But because of this one rule about honey, they sort of shut down the, I have the idea entirely.

And I think that's maybe a symptom of our dichotomous approach to a lot of these things, right? You're either vegan or you're not it's all or nothing. And when we're in that all or nothing mindset, I think we might be missing out on opportunities to make these gradual steps. I think Victoria, you mentioned Meatless Monday, which is a great example of it's an easy accessible first step

Maybe after that first step, they'll take another one. There are studies that suggest that people are more likely to make the behavior change if you give them a small suggestion, as opposed to eliminating something entirely. And there also, I think some evidence to suggest that, people who are vegan or vegetarian or plant-based now were more likely to make a gradual shift to that diet than the ones that went cold-turkey, pun intended there's a report that suggests there, there are more than five times as many former vegans and vegetarians than there are current vegans and vegetarians, which I think it's important to look at that statistic because it says something about the, the number of people who are trying this diet but then not sticking  with it for one reason or another, which I think that's a great question I think for you both is, once someone is already trying a plant forward diet, what are some recommendations that you could give just to help them sustain?

Victoria Maizes: Yeah, I think your point is great. And we do have a little bit of extremism in our society about lots of things, but also about how we adopt or don't adopt as you gave the example, ‘I can't be a vegan because I like honey’. One thing that I find really helpful is when I talk with people about diet change, I say, “let's do this as an experiment.”

And I asked them if they'd be willing to commit for three weeks and not to think about this is going to be a permanent change that they have to make forever, but to really do it for three weeks, pay attention, notice if they feel better. And in what ways they feel better? Cause sometimes it's surprising, you know, sometimes it's a skin rash that goes away or it's a headache that gets better you know, sometimes people have funny food sensitivities, but sometimes people have more energy or their thinking is clear. So it's, it's not it's not always, you have to do this forever.

Brent Kim: Yeah, that's fascinating. Maybe there's something about the sort of short-term commitment that maybe makes it feel a little bit less daunting.

And then I hear you're saying that when they're in make that short [00:38:00] term commitment and then they start to feel benefits. And so then maybe that motivates them to want to continue. Do you offer any sort of nutritional guidance and you know, I, I should caveat this, right? It's kind of funny.

Like people often ask me, I'm thinking about trying a plant forward diet, but I'm, I'm worried about my health. I'm worried about meeting my nutritional needs. But no one ever says I'm, you know, I'm on the standard American diet nutrition records that people always ask the other way around. So that caveat aside are there any sort of nutritional recommendations either around supplementation or anything else that you give to folks who might be interested in trying this.

Victoria Maizes: So we do recommend supplements in a thoughtful way. It's not a one size fits all, but everybody gets the same set of recommendations. But as you point out, people on a vegan diet may require, especially a B12, which comes from animal products. I very much customize my supplementation depending on the rest of someone's medical history.

I think they can be incredibly useful, but I don't think it's a one size fits all situation. Women of childbearing age have a very different set of recommendations. People who have mental health conditions have a different set of recommendations. And so it's good to have that conversation with your healthcare provider and see what would be appropriate in your situation.

Brent Kim: That makes sense, how you'd really want to tailor it to the individual and their life circumstances. Yeah.

I think we all get a little bit anxious about the urgency of climate change.

And I think a problem this big demands, having all of the options on the table, there's one avenue for an intervention in particular I'd love to hear your thoughts on, and that is, do you see a role forpsychedelics or maybe I should say entheogens in helping people to recognize and appreciate the urgency of the situation and maybe kind of, would it help them embrace the sort of societal changes that we need to adopt in order to mitigate climate change. And the short version of this question is can mushrooms help solve the climate crisis?

Andrew Weil: Definitely. Yes. And I think that the potential there is that psychedelic experience can change people's relationship with and appreciation of nature and really motivate them to take steps to turn things around.

And in some ways, I think that's the only thing out there that might have the potential to do that.

Brent Kim: Yeah. Yeah.

Victoria Maizes: Andy, is there anything else that you wanted to say before we close up?

Dr. Weil: [00:00:00] I wonder what are the messages we can give our patients as integrative physicians I think to help them understand that their dietary choices have environmental implications. We tell people to eat an anti-inflammatory diet, to reduce consumption of animal foods, especially beef, to eat lower on the food chain.

But I think it's also helpful for us to talk to patients about the importance of organic farming how our agricultural practices contribute to the development and worsening of zoonotic diseases and things like the president pandemic.

Brent Kim: Yeah, I think that's those are great recommendations to give to your, to your patients. I think another one to consider is that studies suggest that folks who successfully implemented and stuck with the plant-based diets were often the ones that were involved in social groups, whether it's potlucks or an online community, I think there's value in surrounding oneself with like-minded people who are working on those same kinds of changes.

I think another one too is we tend to put a lot of emphasis on behavior change and there's certainly value in that. But nutritionist, Marion Nessel has a quote, which I love, she says, you know, vote with your fork, but also vote with your vote if we're really going to address a problem as big as climate change, it will take more than individuals making these changes and we need behavior change, but we also need broader societal shifts. And that includes, you know, supporting elected representatives who are committed to incentivizing the kinds of shifts that we will need across all sectors.

And you know, policy change is not just limited to government, right? You know, the policies of institutions, it could be, you know, just having a conversation with the head chef of McDonald's and they agree to change something on their menu or, you know, the Aramark and the Sedexo and the food service providers that are catering to all the cafeterias across the country.

No enormous opportunities where one small change in a menu could have a dramatic change for climate. So I really think it's a team effort where we're all in and we need [00:46:00] everybody to get on the same page together.

Victoria Maizes: Thank you so much for joining us today, Brent, and for sharing your wisdom, your research and your expertise.

Brent Kim: It's such a pleasure and a delight thank you very much for having me