hey, everybody. it’s dr. mark hyman. welcome back to the...

© Fat Summit 2. All rights reserved.

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Taking Back Your Health Guest: Chris Kresser

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Dr. Hyman: Hey, everybody. It’s Dr. Mark Hyman. Welcome back to the Fat Summit, part two, where we separate fact from fiction, even more fact from fiction.

I’m here with my good friend and colleague, Dr. Chris Kresser, who is one of the pioneering thinkers in functional medicine. He really is leading the charge in training new physicians. He’s bringing out the essence of functional medicine which is a deep dive into the science of how things work. He looks at the literature. He sifts through it for us. He deciphers the hard questions, and he provides an extraordinary resource on his podcast and his website, ChrisKresser.com. It’s one of my go-to resources as a scientist. As a functional medicine doctor, I got to Chris for trying to figure out what is out there in the literature because he does a lot of the work that I often don’t have time to do.

So I really appreciate Chris, and he’s here with us today. We’re in Oakland. We’re with him in his hometown where he’s got his California Center for Functional Medicine. He’s doing great work here, both doing clinical medicine, bringing the concepts of functional medicine out there for the world to see in a very accessible way. If you actually have not gotten on Chris Kresser’s website, I’d go to ChrisKresser.com. Sign up for his newsletter because it’s really one of my go-to resources.

So welcome to the Fat Summit, part two, Chris.

Chris: Thanks, Mark. It’s so great to be back. I appreciate the invitation.

© Fat Summit 2. All rights reserved. 2

Dr. Hyman: I’m so glad to have you. So we’re going to get right into it. Recently there was an article that came out, and it was in the Journal of the American Medical Association. And it was by the group at Harvard who is very

well respected at the Harvard School of Public Health, Dr. Willett and his colleagues.

And they combined data from the nurses’ health study and the physicians’ health study which were big observational, long term studies where they did food frequency questionnaires. They asked people what they ate every year, and then they correlated that with diseases.

And there were these big headlines in the news that said, “If you eat meat, if you eat animal protein, you’re at a higher risk of death than if you eat plant protein.” So does that mean all of us should become vegans? How do we interpret all this data? It’s really confusing.

Chris: Yeah, it is confusing. I feel sorry for the average person out there. One week it’s, “Butter is bad for you.” Next week it’s, “Butter is good for you.” Same thing with animal products. I think we have to be really careful with what’s called epidemiological or observational data which as you described basically involves taking a whole bunch of people, asking them to report on a questionnaire what they ate which is really sketchy.

Dr. Hyman: And what did you do last week?

Chris: I don’t even know what I had for lunch three days ago and I think a lot about food way more than the average person I think. There have actually been studies on food frequency questionnaires that have shown them to be, as you might suspect, completely unreliable measures of food intake. Most people tend to underreport some things or over report other things. Memory is just sketchy as it goes. That’s one problem.

The second problem is that these things called confounding factors. Let’s say we see, “Hey, this group of people, they ate a lot more meat and then they had more heart attacks and earlier death later in life.” But what else were they doing or not doing? Maybe they weren’t exercising as much. Maybe they were smoking more cigarettes. Maybe they weren’t sleeping as much. Maybe their general awareness of health was just lower overall because historically red meat has been seen as a bad food. So you might expect that people who are eating more meat in this studies are also doing other things that are perceived as…

Dr. Hyman: And they don’t really care about their health, right?


Chris: Because they don’t care about their health. That’s right.

Dr. Hyman: I’m not paying attention. I’m not exercising. I’m going to smoke more, drink more.

Chris: Absolutely.

Dr. Hyman: Eat more processed food.

Chris: Absolutely. And researchers know this. This isn’t new, so they attempt to control for those confounding factors. So they try to remove smoking from the equation, remove drinking from the equation. But the truth is it’s nearly impossible to control for all of the confounding factors.

Here’s an interesting one: the gut microbiome. We now know that gut health plays an incredibly important role in so many different aspects of our overall health including heart disease, including cancer, risk of death from all causes. Nobody’s controlling for somebody’s gut microbiome.

Dr. Hyman: Let’s get a poop sample and see what’s going on.

Chris: Exactly. Exactly. When I look at the health claims, I usually use what I call a three-legged stool to evaluate the claim. So one is the modern, peer-reviewed scientific literature. Enormously important. Evidence-based medicine is something that I completely support, but it’s not the end-all, be-all. There are problems with the way that scientific research is done, and that could be a whole other show or discussion. So there are some limitations there that we have to understand.

And this is where the second leg of the stool comes in.

Dr. Hyman: Let me just stop you there. So people think that if it’s published in a journal, if it’s reported in the news, then it must be true. And you and I know that when you pull back the veil…

Chris: If only that were the case.

Dr. Hyman: If you pull back the veil on these studies, who funded the study? How was it designed? Was it powered to answer the questions? What was it asking? These are all important things that are often not completely evident.

Chris: Absolutely.


Dr. Hyman: I think we often can draw the wrong conclusions from the data. And even the data sometimes isn’t reported correctly.

Chris: The data itself isn’t reported correctly. Oftentimes, I’ll read the conclusion of a study, and then I’ll read the full study and I’ll see that the author’s conclusion…

Dr. Hyman: Don’t match.

Chris: Doesn’t even match the data. It doesn’t match the tables or the figures in the study itself. It’s human nature. Researchers are humans, and they often have a certain perspective or a point of view. And it’s really hard for that not to seep into the way that the study is designed and reported on.

Dr. Hyman: So you’ve got your three-legged stool.

Chris: We’ve got the three-legged stool. Modern research is one. But this is where an ancestral evolutionary perspective is so important I think, and this is the second leg of the stool.

Dr. Hyman: I call that the sniff test.

Chris: Absolutely, the sniff test. A much better way of saying that. We know that all organisms are adapted to survive and thrive in a particular environment. We can look back and say, “What is the natural diet for human beings? What is the diet that we evolved to eat?” Well, guess what? It involves animal protein. It’s primarily meat and fish, wild fruits and vegetables, nuts and seeds, and some starchy plants. That’s what humans ate for the vast majority of our evolutionary history.

So it doesn’t make any sense that animal protein would be problematic for us if you look through that evolutionary lens. That’s just the default. So then we have to start asking why would animal protein be a problem.

Dr. Hyman: Right. What’s the mechanism?

Chris: Yeah. It introduces an element of skepticism. It doesn’t prove that animal protein is not a problem, but it does make us kind of scratch our head and say, “That’s odd.” We’ve never found a traditional group that’s on a vegan or a plant-based diet. Most humans have eaten this way for thousands and thousands of generations. Why would this be a problem? So it’s just a question mark.

And then the third leg of the stool…


Dr. Hyman: Although people might say, people died at 40.

Chris: That’s a popular misconception. I’ll take a moment to correct that. It’s true that our ancestors had shorter lifespans on average than we do today but think of what they were dealing with that we’re not. They had trauma, warfare.

Dr. Hyman: Childhood infections.

Chris: Exposure to the elements. They were sleeping outside, so they had to deal with freezes and cold spells, infections, complete lack of emergency medical care, higher infant mortality rates because of that. And studies by anthropologists that have looked at populations that even had the most rudimentary access to medical care—they had to hike for half a day to get to a rural medical clinic that just had the basics—those populations enjoyed lifespans that are equivalent to our own today. But the difference is they didn’t reach those ages and acquire all of the inflammatory diseases that characterize our old age today. They were relatively healthy until they died.

Dr. Hyman: Half of the people died at two or less and half died at 80.

Chris: Exactly. The average is then 40.

Dr. Hyman: The average is 40. I was just reading the biography of Hamilton, and his wife Eliza Hamilton died at 97. John Adams and Thomas Jefferson died in their late 80s or 90s.

Chris: That’s right. If you escape, that’s what these studies show. If you escape the risk of early death during childhood, then odds are you’re going to live a long, healthy life. We can’t say that today. We can say that odds are we’re going to acquire a number of chronic inflammatory diseases that are going to make our elderly years miserable on average.

Dr. Hyman: We’ve got the three-legged stool.

Chris: Three-legged stool.

Dr. Hyman: Evidence based, evolutionary.

Chris: Evidence based, evolutionary lens.

Dr. Hyman: Context.

Chris: And then clinical experience. And I actually think this is important and plays an important role. If I recommend a vegan, vegetarian diet to 100 people,


some might do okay. A lot of people are not going to do well. If then I have them reintroduce meat in a paleo type of diet, I see them improve and feel better. That means something to me as a clinician. I’m not just going to dismiss that.

Dr. Hyman: It’s considered anecdotal.

Chris: Right. When it’s you and your health, it matters a whole lot more than those other things.

Dr. Hyman: I once was giving a talk at Harvard and David Eisenberg was there, and it was really on autism. And I was talking about this case that I had actually had of this little boy who had autism and we reversed his autism. And the pediatrician was like, “Well, that’s probably just a case of spontaneous remission.” And Dr. Eisenberg goes, “Well, that’s funny because Mark’s had like five cases of spontaneous remission in his practice this year.”

Chris: Incredibly spontaneous. It must be…

Dr. Hyman: I think you and I both see this. I was recommending low fat diets to people for years. I thought the evidence was there. It’s what the cultural dogma was. It’s what the science seemed to show. I never saw the kinds of results that I’m seeing now. People get off insulin in five days. Like in a week.

Chris: That’s unheard of in the conventional literature.

Dr. Hyman: People lose 100 pounds. I never saw that on this other approach, and people struggled. They fell off and now people say, “I feel great. I have energy. I’m not hungry anymore.” And it’s really powerful. So I think those three lenses are really important, and I think they matter. And I think there’s a whole new resurgence of research that is coming around this concept of the n-of-1 research at the NIH.

Chris: That’s right.

Dr. Hyman: The National Institute of Health is actually pioneering the standards by which we can look at an individual and compare them to themselves before and after some intervention.

Chris: Absolutely.

Dr. Hyman: And that really is meaningful and that’s like the anecdote. But it’s actually scientifically validated now.


Chris: That may be the future of research because if we’re going to look at functional medicine as an intervention, you know better than anyone that we don’t just do one thing at a time. We do more than one thing at a time, and so using that old research paradigm isn’t going to work with that. We need to look at before and after with individual people and see what the changes are.

Dr. Hyman: Back to that study that we talked about. I just want to highlight a couple of facts on it because one of the things people don’t realize—if in the culture during the time you’re doing the study meat is seen as bad, then the people who want to take care of themselves and exercise and eat well and have more fruits and vegetables and don’t smoke, they’re not eating meat. Right?

Chris: Yeah.

Dr. Hyman: That’s called the healthy user affect.

Chris: The healthy user bias.

Dr. Hyman: The other part is the people who don’t give a crap about their health, they’re eating lots of meat because they don’t care and they’re doing all these other bad habits.

Chris: One of the best studies I’ve seen that dealt with the healthy user bias—it was ingenious I think. They said, “Let’s look at people who shop at health food stores only.”

Dr. Hyman: Yeah, I saw that.

Chris: Let’s see people who eat meat and who don’t eat meat only who shop at health food stores, and guess what? There was no difference in lifespan or risk of disease.

Dr. Hyman: Well, they both had their risk reduced in half.

Chris: Compared to the general population.

Dr. Hyman: They both had their risk reduced in half.

Chris: Exactly. And that’s just even a really rough way of doing it.

Dr. Hyman: That was like 11,000 people. It was not a small study.

Chris: Yeah, huge.


Dr. Hyman: Very impressive. I’ve seen many of those studies. The other thing is that this was an observational study meaning it cannot prove cause and effect by definition. If you and I wake up every morning and the sun rises, it wasn’t because you and I woke up, but it’s 100% correlation.

Chris: Absolutely.

Dr. Hyman: So in these studies they show correlation but not causation and we talk about this a lot. But it’s really crappy journalism.

Chris: Yeah.

Dr. Hyman: For the journalist not to elucidate that this does not prove anything, it may point to some facts that we should pay attention to and look for consistency, but this is really important that people understand.

Chris: This is why people are turning to blogs like yours and mine to get this information. Most of the people who are reading my blog already are better educated it seems about science than a lot of the so-called science reporters at this point.

Dr. Hyman: There was another study that came out around the same time just last week, showing that people who had higher protein diets which often we thought in medicine are dangerous for your kidneys.

Chris: Right.

Dr. Hyman: We learn these sort of dogmas that seem to be true, but actually may not be true. Then the studies seem to show that the people who had more protein had less belly fat and higher HDLs which goes along with lower risk of heart disease. What do you make of that? It’s sort of the opposite of this other study, right?

Chris: I believe it. Most of the research I’ve seen—I did a pretty deep dive into this because I’m an advocate of a paleo type of diet. I’d better make sure that what I’m recommending is safe. The paleo diet tends to be higher in protein. Like many other myths, it turns out it’s not true that a higher protein intake is problematic for the kidneys. That’s only true if the patient has preexisting kidney disease.

Dr. Hyman: Yeah, if you have kidney failure and you’re on dialysis, you have to watch your protein.


Chris: Absolutely. If I break my arm, I want to put a cast on. That doesn’t mean you need to wear a cast when your arm isn’t broken.

Dr. Hyman: Right. Exactly.

Chris: The second thing is we know that protein is the most satiating of all macronutrients. That means when we eat it we feel full and we feel satisfied. And this explains why high protein diets are associated with weight loss and weight loss is associated with improvement in metabolic function. If you’re overweight, the fastest way that you can improve your markers—your LDL, your HDL, your triglycerides—is to lose weight. And a higher protein diet is a great way to lose weight.

Dr. Hyman: And higher fat too or…?

Chris: Yes, most of the time. I would say high protein…

Dr. Hyman: What do you think is more important, the protein or the fat?

Chris: I think that the research suggests that in many cases where a low carb diet has been effective it may at least in part be because it was a high protein diet. So the protein I think is a crucial part of that equation. And then whether higher fat or moderate carb, moderate fat is the best option I think is a really individual question. And this is why there’s been so much controversy and so many studies saying low fat better, high fat better. There is actually no one answer for everybody.

Dr. Hyman: We’re all different. Imagine that.

Chris: Crazy. Crazy concept. Overall, I think the research shows that at least in the short term a lower carb, higher fat diet will be more effective for more people.

Dr. Hyman: Not for everybody.

Chris: Not for everyone and not necessarily over the long term.

Dr. Hyman: Right. Amazing. So let’s dive deeper into this. We got started on the meat track and the protein. The next sort of question in this is does it matter what kind of meat you eat? There’s this recent study comparing organic, grass-fed meat versus CAFO or feedlot meat. Are there meaningful differences or not and what’s your take on that?


Chris: Absolutely there are, and it’s another case of science journalism gone awry because all you have to do if you’re a science journalist is go and actually look at the scientific literature and compare the results of many studies with the one that was just published and look at the weight of evidence and what the weight of evidence says.

Dr. Hyman: So important.

Chris: There are three primary differences between organic meat and conventional meat. The first is fatty acid profile. So organic meat has 47% higher omega-3 fat intake, and this is absolutely crucial because omega-3 fats are anti-inflammatory and virtually every disease that could kill us in our old age…

Dr. Hyman: Inflammatory.

Chris: Is an inflammatory condition. And most Americans don’t get enough omega-3 fat. So that’s end of the story basically. That’s enough of a reason just to choose organic meats.

Dr. Hyman: And it’s significant, the amount of difference.

Chris: 47% higher. That’s not insubstantial.

Dr. Hyman: I’ve seen even more than that in some studies.

Chris: So that’s on average. It depends on where the meat’s coming from and whether it’s grass-fed or whether it’s grain-fed organic. We’ll come back to that.

So the second difference is antibiotics. The definition of organic meat—one of them—is that antibiotics cannot be used in the production of the animals. In the conventional model, farmers use antibiotics to promote rapid growth. And what’s interesting is we now understand how this works. The antibiotics cause a state of chronic dysbiosis. They disrupt the gut microbiome in the animals, and this predisposes them to gain weight. Well, guess what? That happens in humans too. So if we’re eating the meat that has a little bit of antibiotics in it, we induce a state of dysbiosis in ourselves that could predispose us to gain weight.

Actually eating conventional meat could theoretically put people at risk for gaining more weight because it disrupts your gut microbiome.

Dr. Hyman: By the way, this is something that the farmers know.


Chris: Absolutely.

Dr. Hyman: This is why they use antibiotics, not just to prevent infection. It’s a growth promoter.

Chris: Fatten them up.

Dr. Hyman: Fatten them up. Exactly.

Chris: They’ve know this for years. What they haven’t known was the mechanism, and now that we understand the mechanism we see how that could actually transfer over into humans. It’s even more reason to eat organic meat.

Dr. Hyman: Wait. I just have to tell a quick anecdote about farmers and then we’ll go back. I remember reading as I was doing research for my book that the pig farmers in the 30s and 40s wanted to fatten up the pigs and had all this cheap coconut oil. So they fed them all this coconut fat, and they started losing weight.

Chris: Right. Oops.

Dr. Hyman: They’re like, “Shoot.”

Chris: That didn’t work out.

Dr. Hyman: That’s when they started figuring out the grain.

Chris: Better start with the gummy bears and all that stuff, the conventional.

So the third thing is pesticide residue. This is a somewhat controversial area, but there are some studies that suggest that pesticide residue is associated with increased risk of ADHD and lower intelligence and IQ in kids especially and may have adverse effects in adults as well. So those are the three main differences between organic and non-organic.

Dr. Hyman: Although I read recently there was a study that came out looking at even in organic that lamb and others had higher levels of pesticides even if they were grass-fed because of all the pollution in the environment.

Chris: That’s a whole other question is just how we’re screwing up the environment in general. But if you look at the research, typically organic meats will have lower pesticide residue than nonorganic meats. But I’m glad you brought up grass-fed because what we’ve been talking about is organic


versus nonorganic. That doesn’t really say a lot about what the animals are eating. It’s true that the definition of organic means they have to have access for pasture or I think 60% of the time.

But there are meats you can buy that are 100% grass-fed, and why would that be even better than organic animals that are fed some grain and some grass? Well, the grass is what contains most of the nutrients. Vitamin A, beta-carotene, vitamin K. Animals biotransform those nutrients into active vitamin A, or retinal, and vitamin K-2, which we then get when we eat those animals.

So if you look at the difference between grass-fed animals and even organic grain-fed animals, you’re going to see higher levels of a lot of nutrients across the board in the pasture-raised animals.

Dr. Hyman: And they have higher levels of antioxidants.

Chris: Antioxidants.

Dr. Hyman: Catalase.

Chris: Exactly.

Dr. Hyman: All those interesting glutathione-producing nutrients which is fascinating to me.

Chris: Some scientists in these articles say, “Well, these aren’t essential nutrients.” Well, if you read Jo Robinson’s book Eat Wild and you look at some

of the recent research, they may not be essential in the sense that we can’t live without them. But they’re essential if we want to live well and be healthy. So if you look at a spectrum, I would say 100% grass-fed organic is the cream of the crop so to speak. Then we have organic that’s grain-fed and some grass, and then we have nonorganic. And that’s the kind of order that you should be shooting for.

Dr. Hyman: So then the issue is how do we do this at scale. So if we’re saying we should all be eating more meat and we don’t want a feedlot meat, which is by the way what’s frightening when you look at the data on this, 70% of the world’s agricultural surface which is about 30% of the planet is used for growing animals for human consumption. It takes up 70% of the world’s fresh water. By the way, there’s only 5% of the world’s water which is fresh water. One percent’s in Russia and Putin’s got control of that. That’s 4% for the rest of us. That’s all using water for irrigation to grow crops or otherwise to support industrial agriculture.


Industrial agriculture also degrades the soil, depletes our aquifers, pollutes our waterways with pesticides and nitrogen fertilizer that destroys entire water systems like in the Gulf of Mexico. One-fifth of all of our fossil fuels are used to grow animals for human consumption and industrial agriculture which by the way is more energy than is used for all transportation of cars, planes, and boats combined.

When you look at this, you go, “Oh god, yeah. I want to eat more meat but how do we do this as a species and how do we switch from this industrial agriculture to grass-fed? And is that enough even to support us all?” What should we do? Should we be doing factory-raised—I mean the…

Chris: Farm.

Dr. Hyman: What’s the word? Laboratory meat where they’re growing meat in the lab.

Chris: Yeah, I wouldn’t rule that out in the future, but I think there are a lot of questions that still need to be answered about that.

Dr. Hyman: How do we do this? As concerned environmental conscious…

Chris: First of all, I’m completely sympathetic to this view. It’s something I care a lot about—the health of the planet. And I was a macrobiotic vegan at one point because when I looked at the state of industrialized animal product production, whether you’re talking about meat or dairy or whatever, I said, “I don’t want to participate in this.” At the time I thought my only option was to not eat meat and not eat any animal products at all.

But there is another option which is to produce the meat in a more sustainable way. And it turns out there are a lot of misconceptions about how energy and water-intensive this type of animal husbandry is. First of all, there’s a large amount of land around the world that’s not suitable for the production of agricultural crops. This is like hilly, rocky terrain that can’t be used for farming plants but could be used for raising livestock. And that land can be utilized. Allan Savory talks a lot about how we can use these lands way more effectively than they’re being used right now.

The second thing is that…

Dr. Hyman: Wait. So for people that don’t know what that is, restorative grazing is this idea that if you mimic traditional animal herds and populations by moving them around and intensively fertilizing and then moving on to the next plot of land you can literally restore deserts and bring them back to


grasslands. And actually, his theory which is actually being studied now at the Savory Institute is that you can actually take back—if we apply this at scale, you can take about our environmental climate change situation so that we’re sequestering enough carbon to take us back to the pre-industrial age which is pretty shocking when you think about it.

Chris: Yes.

Dr. Hyman: So if we all ate grass-fed meat, maybe it’s going to reverse climate change.

Chris: It’s been shown in some studies to actually sequester carbon. So instead of being this carbon nightmare which it’s portrayed as it could actually help heal the planet.

Dr. Hyman: So restoring the grass outweighs the cow farts that happen.

Chris: Exactly. And then there’s often this figure that’s thrown around that it takes 2500 gallons of water to…

Dr. Hyman: To raise a pound of meat.

Chris: To raise a pound of meat. But that wasn’t a sophisticated way of looking at the amount of water. There’s green water and there’s blue water, the blue water being the fresh water that you were referring to that needs to be brought in in order to raise the meat rather than rain and other water in the environment.

And Diana Rogers actually, who is a pasture-based farmer and also a nutritionist, has written some really great articles about this recently. But essentially, she points to research that shows it takes about 400 gallons actually of water to raise a pound of meat which is similar to the amount of water it takes to raise avocadoes and walnuts and some other plant foods.

Dr. Hyman: And two gallons for one almond or something.

Chris: Yeah. In some cases, it’s actually more like 100 gallons per pound of meat. So there’s a lot of misconceptions about the amount of water it takes. There are misconceptions about how carbon negative or positive, depending on how you look at it, raising meat is. And I think there is a way to do it that respects the earth. And in fact, the argument has been made that we need actually to raise animals in order to protect the soils.


This monocropping agricultural system that we have now where we have just fields of soy beans and fields of corn is destroying the topsoil. Without animals to put inputs back into the soil, we’re going to be in a really scary situation in a short period of time. And we’re not going to be able to feed ourselves using Soylent Green.

Dr. Hyman: Yeah. The guy who runs Polyface Farm, he says…

Chris: Joe Salatin.

Dr. Hyman: Yeah, Joe Salatin’s like, “I’m a soil farmer. I’m a grass farmer. The animals are just sort of a byproduct of taking care of the…”

Chris: The chickens are in a big enclosure and they poop on the soil there and return the nitrogen to the soil. Then they move it to another place. It’s amazing the results they’re getting.

Dr. Hyman: So you think it’s possible for people to shift towards more grass-fed meat, but the cost is there for people, right?

Chris: The cost is there.

Dr. Hyman: Do you think it’s just a matter of time?

Chris: I think it’s a matter of time. I think it’s also a matter of shifting priorities, quite honestly. We’re spending less as a percentage of our income on food than we ever had.

Dr. Hyman: Yeah, I read the data. It was like 9% of our income in America is on food. In Europe, it’s 20%. In some countries, it’s 50%.

Chris: Even our country used to be that. We’re pretty addicted to our toys, and we want to have all the latest gizmos and gadgets. There’s nothing wrong with that per se, but if we’re buying Top Ramen and microwave dinners instead, then that’s when it becomes a problem.

Dr. Hyman: So you’re not worried about the saturated fat in meat.

Chris: I love the saturated fat in meat. That’s what makes it taste really good. I’m not worried about it. Fifty years ago the dominant paradigm idea—in some circles still today—is that saturated fat is harmful. It increases the risk of heart disease because it increases your blood cholesterol. But now we’ve seen many, many large reviews that have shown that saturated fat not only doesn’t


affect blood cholesterol on average. More importantly, it doesn’t increase the risk of heart disease and may even have an inverse association with stroke.

So in other words, the more saturated fat you eat, the lower your chances of having a stroke.

Dr. Hyman: That other study that came out looking at basically butter in the blood found that in 3000 people over 15 years that those with the highest levels of dairy fat in their blood had the lowest risk of diabetes by about 40-50%.

Chris: The research on dairy fat is overwhelming at this point. Full fat dairy, but not nonfat or low fat which is really interesting, is consistently associated with metabolic benefits and cardiovascular benefits, lower risk of diabetes, lower risk of heart disease, lower risk of stroke. And it seems like every week a study is published that confirms these results. There’s a consensus now.

Dr. Hyman: Yeah, it’s true. And there are some experts out there who say, “Well, it’s really not true that this is the story because we dramatically increased our intake of fat. We have increased our intake of meat, and so that’s what’s correlating with this epidemic of obesity and diabetes and heart disease.” But when you actually look at the United States agriculture records, that’s true. But what actually it says is that our consumption of red meat has gone dramatically down, over in half. Our consumption of butter and lard and tallow has been cut in half or more. Our consumption of eggs has dramatically reduced. But what has increased is our intake of chicken—which I’ll get to in a minute—and our intake of vegetable oils.

Chris: Soybean oil.

Dr. Hyman: Soybean oil. So soybean oil is very inflammatory. It also seems to be associated with increased cardiovascular harm. You and I have a very different view from a lot of people out there. And that chicken—do you know Dr. Hibbeln, Joe Hibbeln?

Chris: Yes, sure.

Dr. Hyman: I was with him in Washington. He was telling me about chicken, and he was saying, “Chicken is actually not—even though it’s the white meat, it’s actually bad for you because of all the omega-6 fats because they’re eating all these grains and have all these vegetable oils that are inflammatory.” So he says they’re trying to design chickens with omega-3 fats in them, so it’ll be like a chicken-fish.


Chris: It’s ironic because that’s always been perceived as the healthy meat, right? It is the one—we eat the least amount of chicken of all the meats because it’s the hardest to get 100% pasture-raised, just eating a normal chicken diet. Even in the Bay Area, like the home of all the…

Dr. Hyman: Eating grubs. Where can you get a chicken that’s eating grubs?

Chris: Grubs and worms. And when you do get it, it’s this big.

Dr. Hyman: Right.

Chris: The pasture-raised chicken is this big, and it barely feeds my family of three. It’s not this huge thing that’s totally artificial. Most people have never even seen what a real chicken looks like when it eats a natural diet.

Dr. Hyman: I know.

Chris: This is why chicken used to be Sunday dinner. It was a special occasion because if you kill a cow, a lot of people are going to be fed. You kill a chicken, maybe you’re going to feed three or four people if they’re not very hungry.

Dr. Hyman: So what do you then say to your friends who are vegan or vegetarian? You and I both have a lot of friends and colleagues who are vegan and really believe in this lifestyle. We were talking a little earlier about the people who started Café Gratitude which is a vegan café. And now they’ve sort of switched and become people who actually have their own farm and raise animals and slaughter animals. So what do you say in terms of the nutritional benefits or the nutritional potential harm from being a vegan/vegetarian? How would you sort of address that?

Chris: It’s a complex question actually. First of all, I never tell…

Dr. Hyman: If it was easy, anybody could answer it. That’s why I’m asking you.

Chris: First of all, I’m a pretty hands-off guy. If someone’s a vegan and they’re my friend, I’m not going to say anything to them about their vegan diet.

Dr. Hyman: You’re not going to protest in front of their house with a sign? Send them death threats. No?

Chris: Yeah, send them death threats. That’s right. Unless they come to me with a question, then I’ll share my opinion. If it’s working for you, great. That’s


my belief and there are many reasons people make the dietary choices they do. When I was a macrobiotic vegan, I wouldn’t have appreciated somebody beating me over the head and trying to get me to follow a paleo type of diet. So I leave that alone.

But if someone comes to me, for example, and let’s say it’s a woman who wants to get pregnant and she’s been on a vegan diet. And she asks me, “What do you think? Should I continue with my vegan diet? I’m considering eating meat.” I will say something like this, “Well, some people can do ok with particularly a vegetarian diet. Fewer people in my opinion do well with a long term vegan diet.” There are a lot of factors that determine whether someone will or won’t do well with these plant-based diets. One of them is…

Dr. Hyman: You’re eating eggs and dairy you’re doing better than if you’re just totally plant-based.

Chris: Yes, because eggs and dairy have a lot of nutrients like vitamin A and choline and things that are hard to get—

Dr. Hyman: And B12.

Chris: B12—in a completely plant-based diet. But the plants have the precursor nutrients. This is something that I don’t think a lot of people understand. Plants have the precursor nutrients. Those precursory nutrients like beta-carotene or vitamin K-1 need to be converted into the active form. So in the case of beta-carotene, that would be retinol. In the case of K-1, that would be K-2, to have the full benefit that they have in our bodies.

Now, some people make those conversions pretty well. Many people don’t make them well, and some people don’t make them at all. So if you’ve ever seen someone who’s done like a juice fast with carrots and their skin turns kind of orange, that’s someone who doesn’t convert beta-carotene into retinol.

Dr. Hyman: I tried that.

Chris: That’s why. The beta-carotene builds up.

Dr. Hyman: I was like, “Man, I look so orange. What’s going on here?”

Chris: Exactly. So you wouldn’t do well on 100% plant-based diet because you can’t make those conversions. Then we take someone like Rich Roll who is a phenomenal…

Dr. Hyman: Athlete.


Chris: Athlete, triathlete. He’s been on a vegan diet for a long time.

Dr. Hyman: And done five Ironmans in seven days.

Chris: Five Ironmans in seven days. It’s obviously working for him. No one can say that—but he supplements as far as I know and understands how to do that well, and he is an exception.

Dr. Hyman: He does a tremendous amount of exercise which actually helps to I think help with protein synthesis.

Chris: Activate some of those—yes, yes. But the point is he is an exceptional specimen obviously.

Dr. Hyman: He’s an anomaly.

Chris: And not the typical person. We know from the research that a lot of nutrient deficiencies are more common on vegetarian and vegan diets. And especially now that we have more sensitive markers for deficiency, we’re seeing this be way more clear.

So just to give you one example. Earlier studies found that there wasn’t as big of a difference in serum B12 levels between vegetarians and vegans and omnivores as you might expect. But using more sensitive markers like methylmalonic acid and homocysteine, you see very big differences between vegans and vegetarians and omnivores.

What I would say is, on average, plant-based diets have a greater risk of leading to deficiencies of key nutrients that we as humans need and are essential to us.

Dr. Hyman: Like A and K and D.

Chris: Vitamin B12, EPA, and DHA which you can eat alpha-linolenic acid and walnuts and flax. But again, less than one-half of 1% of ALA is converted into DHA, and that’s in a best-case scenario. Some can pull it off, but many cannot.

Dr. Hyman: And you and I are practicing doctors. That’s what we do, right? And I had the privilege of over 20 years testing thousands and tens of thousands of patients on nutritional levels.

Chris: Yes.


Dr. Hyman: It’s stunning to me what we see and the amount of nutritional deficiencies in Americans at large and particularly in people who are vegans. We see dramatically low levels of iron, vitamin A, vitamin K, omega-3 fats, vitamin D, and B12. Their health is affected by it. If you have to eat a diet where you’re dependent on supplements, and I do think that the supplement question is a whole other question. I do think people because even the rest of us are eating diets that are nutrient-poor for many reasons, but I think it’s really striking to me. I wouldn’t have believed it if I hadn’t actually seen it for myself…

Chris: Seen the results.

Dr. Hyman: For decades how repeatedly I see these factors. Unless you know what you’re doing it can be very challenging. And also protein. Let’s talk about protein. Is animal protein and plant protein equivalent? And particularly as you age, is there a difference in the ability to synthesize muscle from plant versus animal? We know that the disease of aging is really what we call sarcopenia which means loss of muscle.

Chris: Loss of muscle.

Dr. Hyman: If that happens, even if you’re skinny, you’re going to get sick and die.

Chris: You’re going to be at a high risk.

Dr. Hyman: High risk for heart attack, for cancer, for stroke, for dementia, and diabetes even if you’re skinny if you lose muscle. So what role does plant versus animal protein play in muscle?

Chris: I think that’s one of the most important roles that animal protein plays is in the greater ability that it has to build muscle mass and maintain muscle mass, particularly in the elderly. This is one of the deficiencies of the acid/alkaline hypothesis and the idea that we shouldn’t eat protein because it’s acidic.

When I was doing a presentation that debunked that myth, I took a deep dive into the research on animal protein and muscle and bone health in the elderly and saw that animal protein is consistently associated with better bone health, lower risk of falls, greater muscle mass, and then, as a consequence, better overall health in everybody but especially in the elderly. It becomes even more important as we age because as we age our muscle mass tends to decline, all other things being equal.


Of course, we can combat that by exercising and particularly weightlifting as we get older which helps to build muscle mass. But animal protein has an anabolic effect which is an ability to build muscle that plant protein doesn’t have.

Dr. Hyman: That’s a big difference because vegetarians they eat beans and rice. You’re going to get plenty of protein and broccoli has protein and that’s a big myth. I think as I see patients who are older and I work with them on aging and reversing aging I do notice this. I put people on protein and I’ve started using whey protein, grass-fed whey protein. Even though I’m not a big dairy fan, I really see that it really dramatically increases muscle synthesis, and it’s got a high level of lysine which is a specific amino acid that catalyzes.

Plant proteins—you’d have to eat six cups of quinoa to be equivalent of a four-ounce piece of meat. Good luck with eating six cups of quinoa.

Chris: That’s why those body builders aren’t eating quinoa protein. Again, you have your exceptions to the rule that do do that, but if there’s one thing body builders know a little bit about, it’s how to build muscle. Whey protein has been the staple. Or any other kind of animal protein.

Dr. Hyman: That’s true. So Chris, we’ve been talking about protein and meat particularly. I think we got a really good view for people. I really appreciate the depth of that conversation, but I want to sort of flip and start talking about carbs for a minute. You and I have had some conversations, and I actually asked you to read my book Eat Fat, Get Thin before. And you had some very

interesting comments that were challenging some of my assumptions about eating very low carb or low carb diets.

What I really like about you is you’re thoughtful. You look at the literature; you think about it. You see what the sort of backstory is. You try to read between the lines and not just look at the headlines. It’s easy for peop le to go extreme and say, “All sugar is bad and carbs are bad so we should be eating no carbs. All fat’s bad; we should be eating low fat. All fat’s good; we should be eating all fat.” Those extremes are probably not what most of us should be doing. And there are outliers, like you said, who may need different—ketogenic diets would do great for some people with epilepsy or with diabetes or some outliers. But you said there’s a variety of humans out there and some people don’t do as well with a lower carb diet.

So what have you found when working with patients and in the literature around people eating different amounts of carbs and what makes sense?


Where have you landed in the carb world of low carb versus high carb or medium carb?

Chris: Where I’ve landed is that there’s no one-size-fits-all approach. So it’s very difficult to give one recommendation that would be suitable for everyone. And this is why I called my book, when I first published it, Your Personal Paleo Code because the idea was, look, there are certain foods that nobody thrives

on. Pizza being one of them. We might like it, but if we eat an all pizza diet, we’re not going to thrive. Processed and refined flour, sugar, industrial seed oils. All of these processed foods we can just throw those out because there’s no individual out there that’s going to do really well on those foods and not well on real foods. So there are some basic assumptions we can make that apply to everybody.

But beyond that, within that template of a nutrient-dense, whole foods diet, I think there’s a lot of room for flexibility and variation depending on individual needs. So some of those needs and differences might be—well, let’s just use an example. Let’s take someone who’s 60 pounds overweight, primarily sedentary, office job. They’re pre-diabetic, and they’ve got a family history of heart disease and diabetes. And their main goal, the main thing that they need to do, is lose weight and improve their metabolic health. Then let’s take a woman who has three children. She is working full-time. She’s getting about five hours of sleep a night and has an enormous stress level and is doing CrossFit three or four times a week and is lean.

Should those two people have the same diet?

Dr. Hyman: Probably not.

Chris: Should they have the same fat and carbohydrate intake?

Dr. Hyman: One’s a therapeutic diet. One would be a maintenance diet, right?

Chris: Right. In the case of the person who’s overweight, I would argue that a low carb diet at least initially might be a really good choice for that person. It’s going to help them lose weight quickly. Increasing their protein intake will increase their satiety and help them stick with their diet. It might improve their lipid profiles as you mentioned earlier. They’ll see a decrease in their LDL probably and an increase in their HDL, a decrease in triglycerides and all kinds of other risk factors.

But then if you put that working mother who’s stressed out and burning a candle at both ends on a very low carb diet, what I’ve seen…


Dr. Hyman: She’s going to wipe out.

Chris: She’s going to wipe out. She’s going to crash in the afternoon. She’s going to start having insomnia. So it’s not only going to be not having enough time for sleep. When she does try to sleep it’s not going to go well. She might become amenorrheic. She might lose her period. She might start to have mood disorder or anxiety or something like that. And nine times out of 10 when I have that mom add more real food carb.

Dr. Hyman: Like what?

Chris: Not flour, not sugar, not muffins at Starbucks.

Dr. Hyman: Brown rice, pasta, what?

Chris: Sweet potatoes, even white potatoes particularly if they’re cooked and cooled and they form resistant starch.

Dr. Hyman: The fingerling potatoes from Peru.

Chris: Yeah. The small red potatoes. Some of the less commonly eaten starches like plantain or taro or yucca. There are a lot of different options out there. And pumpkins. The kabocha squashes, the dense squashes, and whole fruit. Those are excellent carbohydrate choices for someone like that and they do not impact blood sugar in the way that cheese doodles do. You can’t compare those kind of carbohydrates with Big Gulps and pizzas.

Dr. Hyman: But you didn’t mention in there beans. You didn’t mention whole grains. You’re talking about sweet potatoes and potatoes and yuccas and taro and plantains. Where are the grains—

Chris: This is where I differ from other kind of paleo advocates. I even resist using the term paleo now because I think it’s too limiting. I do think that whole grains and legumes, if they’re well tolerated and if they’re properly prepared, can play a role in a healthy diet overall. But when you look at the nutrient density of grains and legumes compared to the foods that I just mentioned, it’s lower.

Dr. Hyman: Yeah.

Chris: I don’t recommend that someone eat a ton of grains and legumes simply because the nutrients aren’t there. But having a bowl of quinoa or some lentils that have been soaked and properly prepared several times a week in the context of this very overall nutrient dense diet, I cannot see any


research that shows that that would be problematic. And that’s where I disagree with a lot of the hardcore, strict paleo.

Dr. Hyman: You were there when I was in Arizona. We were in Arizona and I came up with this idea of a pegan diet as a joke.

Chris: Absolutely.

Dr. Hyman: And it turned out that’s exactly what you’re talking about. Small amounts of these other foods. It’s very open and inclusive, but it focuses on concepts of very low glycemic diets.

Chris: Nutrient density.

Dr. Hyman: Nutrient density. Lots of plant foods. Grass-fed meat. Lots of nuts and seeds. No processed food. No antibiotics and no hormones and no crap in your diet. Those are just common sense principles.

Chris: Common sense things. What we’ve been eating for millennia. The grains and legumes are more recent, but we have been eating them for at least 10,000 years. And many research reports now suggest much earlier than that. We’ve found evidence of grain and legume consumption at archaeological sites that suggest that they were part of our diet for longer than was typically believed. So legumes are actually paleo despite the argument that they’re not paleo.

Dr. Hyman: We ate them differently too. I just came back to Utah. We went on a river trip and went on these ancient grounds. The Indians used to live there a 1000 years ago. They had a stone and a little rock and then a stone which was how they ground their grain. You had to grind your grain with a stone with another stone. That’s a different…

Chris: That’s a lot different than eating a baguette or a croissant.

Dr. Hyman: I met with a Hopi woman who was on the trip with us, and she’s like, “I was told by my doctor I should not filter out from our corn. I shouldn’t filter out all the fiber. I should leave it in there.”

Chris: Yes.

Dr. Hyman: So they were like now taking it all out, and they had kind of adapted this Western view.

Chris: Full circle.


Dr. Hyman: Pretty fascinating.

Chris: Here’s the other thing is that we know that the plants and grains and legumes that our ancestors did eat were probably very different in their sugar content. Again, I have to plug Jo Robinson’s book which is amazing because she says one of the biggest differences between our modern diet and our traditional diet has been the cultivation of plants to make them sweeter over time.

So if you look at corn, the original corn was like these tiny, little teosintes I think it’s called.

Dr. Hyman: Blue corn and red corn.

Chris: Those little, tiny things that are this big, and they’re not sweet.

Dr. Hyman: No. The Indian corn…

Chris: Now our corn is just like almost candy.

Dr. Hyman: It is. I had some last night, and I was like, “Wow, I want to eat all of it because it’s like sugar.”

Chris: We’ve done this over time where we’ve turned even plants...

Dr. Hyman: Into candy.

Chris: Into sugar basically.

Dr. Hyman: Anyway, it’s in wheat. We’ve taken the dwarf wheat, which used to be the einkorn traditional wheat and it’s not got huge amounts of super starch in it. Amylopectin A, which is worse than table sugar for your blood.

Chris: I’m sure you’ve had patients like—I had a patient who I had just talked to last week who was over in Europe. She’s gluten intolerant. She ate wheat there.

Dr. Hyman: It’s because they don’t allow that wheat.

Chris: Didn’t have any problem.

Dr. Hyman: Let’s sort of loop back now to a topic that’s sort of hot in the news. A couple of weeks ago there was a review article by Dr. Mozaffarian in PLOS which was basically saying, “Is butter back?” And they reviewed like I


think 600,000 people and 15 studies. It was like 6 million patient years. And they were like, “Gosh, there doesn’t seem to be a whole lot of evidence that butter is bad. In fact, there seems to be maybe an inverse correlation with diabetes and no effect on heart disease.” So what do you make of that? These are observational studies.

Chris: Again, I read the conclusion actually just a couple of days ago, and the conclusion was very cautious. It was like there’s no evidence to support butter restriction. But they didn’t go into all the evidence that actually suggests that eating butter isn’t just not harmful, that it actually may be beneficial.

Dr. Hyman: May be helpful.

Chris: It may help you prevent getting diabetes because of all the—and the mechanisms are not fully understood, but they’re thought to involve beneficial fats. Dairy fat has natural trans fats. We’ve heard all about the bad artificial trans fats, but conjugated linoleic acid, for example, is a natural trans fat that seems to have health benefits.

Dr. Hyman: Weight loss, diabetes, cancer.

Chris: Absolutely. Butter has some nutrients that are hard to get elsewhere in a diet, like vitamin A for example and vitamin K-2 especially if the butter is pasture-raised. So where we come back to…

Dr. Hyman: Not pasteurized. Pasture-raised.

Chris: Pasture-raised. That’s right. Grass-fed. So one wonders—this was just looking at all butter, including conventional butter.

Dr. Hyman: Not grass-fed butter.

Chris: Right. If the study had just looked at pasture-raised, grass-fed butter, the results probably would’ve been even better.

Dr. Hyman: And by the way, those original studies we talked about, none of those were on grass-fed beef. They were all on feedlot beef.

Chris: Absolutely. You’ve got to keep that in mind. It’s all about the context. We order butter from a farmer, and when we get it, it’s orange.

Dr. Hyman: Orange. Right.

Chris: People look at it and they’re like, “Is that cheddar cheese?”


Dr. Hyman: Is that margarine?

Chris: Yeah, margarine. God forbid it’s margarine. They know us well enough to know it’s not margarine. But they say, “Is that cheddar cheese? Can I have a piece of that.” And I’m like, “No. That’s butter.” We were just traveling in Hawaii, and I was driving around looking for a groovy kind of health food store and couldn’t find one. So I’d go into like the Food Save and buy some butter, and I bought it and it was white. I was like, “What is this? This isn’t butter.” You can see the difference.

Dr. Hyman: Yeah, absolutely. So what about the people who say, “Oh, saturated fat is inflammatory. It seems to active inflammatory pathways in the body, and we should be concerned about it.”

Chris: It definitely does if you’re a mouse.

Dr. Hyman: So in animal studies, it’s usually a problem. What if you’re a human?

Chris: Well, this is where it all comes down to context. So if you are a human and you’re eating large amounts of saturated fat and you’re also drinking Big Gulps and eating cheese doodles and muffins and cookies and pizza, then the combination of those acellular carbohydrates, which mean your body does not have to spend any energy breaking them down. The carbohydrate is just completely available for absorption.

Dr. Hyman: It’s like mainlining sugar.

Chris: Mainlining sugar. It’s feeding your harmful bacteria in your gut. It’s giving them a field day, creating a dysbiotic state which then leads to what’s called metabolic endotoxemia. So it’s a proliferation of bad bacteria that produces endotoxins. Those endotoxins then cause a leaky gut. They cause our gut to become permeable. They get into the blood stream and it creates an inflammatory state. So in that situation, saturated fat…

Dr. Hyman: I call that sweet fat.

Chris: Sweet fat.

Dr. Hyman: Sweet fat. It’s ice cream. It’s doughnuts. It’s French fries. It’s starch and sugar combined with fat.

Chris: If you’re eating like a standard American diet and you’re eating high saturated fat, it’s probably not going to do you any favors.


Dr. Hyman: You’d think if all this data, these large trials and observational data, these are people eating saturated fat in the context of American diets…

Chris: And even then it’s not convincing.

Dr. Hyman: Even then it was hard to see any effect.

Chris: It’s not convincing. So these studies that drive down and get really myopically focused on mechanisms, they miss that. This is where that step back is really important. If you’re going to show in a mechanistic study that saturated fat causes metabolic endotoxemia and you’re going to argue, therefore, that it’s inflammatory, then you have to step back and account for the observational data in that case that shows that on average saturated fat is not increasing the risk of heart disease. How do you explain that?

Dr. Hyman: It doesn’t make sense. You have to reconcile…

Chris: There must be some other mechanism that is countering that mechanism. That’s what happens when you get too focused on the details. You could lose sight of the big picture, but there’s one other thing which is that studies have shown that a higher fiber intake can mitigate the potentially adverse effects on the gut flora of a high fat diet. This is where context is important. If you’re eating non-starchy vegetables, nuts and seeds, maybe some legumes and grains and some starchy plants that are fibrous, like our ancestors did, and you’re eating a high fat diet…

Dr. Hyman: This is so key. This is so key, Chris. What you’re saying, I just want people to reinforce this point because if you eat—and look at the data. If you eat saturated fat and you have plenty of omega-3s and lots of fiber and not a lot of starch and sugar, no problem. But if you’re eating saturated fat with no fiber, no omega-3 fats and tons of sugar, you’re in trouble.

Chris: That’s right. And you have to remember that when you see those headlines—for anyone who’s listening to this right now—and it says, “High fat diet shown to be harmful,” and you’re eating the way you just described, they’re not talking about you. Those are not the people in the study. They’re not eating broccoli and kale and a sweet potato along with their higher fat cut of meat. They’re eating a bun and fries and drinking a big soda along with it. So you can’t generalize those study results to you if you’re eating a healthy diet.

Dr. Hyman: I could talk to you all day. We could talk all weekend. I could go through so much, and we could talk back for more. I want to finish up with


one more topic which is another study that came out, and this is just on a pile of many, many other studies. The same group from Harvard—this was just in JAMA I think two weeks ago—looking at the polyunsaturated fat diets and the

risk of disease and heart disease. And they found that looking at all fat, total fat was an inverse correlation with mortality. Meaning the more fat you ate and less carbs you ate—starchy carbs—the better off you were.

But then they kind of broke it down. And they looked at polyunsaturated fat, which is vegetable oil like soybean oil, compared to olive oil, compared to saturated fat and compared to omega-3 fats. And what they found was that the polyunsaturated fat group seemed to have a reduction in mortality. And the omega-3 fat did too and saturated fat not so much, and olive oil was better. So it showed that these refined vegetable oils were better than saturated fat. And I don’t know how to reconcile that with what we seem to know is the opposite of that. So how would you address that?

Chris: I would say the kind of similar answer to the first question that we started with. There are inherent problems with epidemiology, and there are a lot of different ways that you can massage data. And I’m not saying massage it in an intentional way. I’m not accusing the researchers of fraud or anything like that. I’m just saying that when you look for something hard enough…

Dr. Hyman: Put the emphasis on the wrong syllable.

Chris: Yes, exactly. We have 50 years of data that supposedly told us that saturated fat was harmful. But then we have newer, better designed, more comprehensive studies that did a better job of controlling for the healthy user bias which you and I talked about before that show us that it’s not.

At the end of the day, at some point I always come back to that three-legged stool for interpreting health claims. And is it even possible to eat a diet that’s as high in polyunsaturated fat without machines that can make industrial seed oils? No way. We’re going to have some polyunsaturated fat that we get through foods like avocadoes and nuts that we can naturally get.

Dr. Hyman: In food. In whole food.

Chris: In whole food. But we can’t reach the levels of polyunsaturated fat that are often recommended or observed in these studies without…

Dr. Hyman: You’d have to eat like 50 pounds of sunflower oil.

Chris: Or seeds.


Dr. Hyman: Sunflower seeds.

Chris: Or just like sit there all day grinding the oil out of them. So it doesn’t add up from an evolutionary perspective, and it doesn’t match with the large body of evidence that’s shown that overall saturated fat intake is not associated with an increased risk of heart disease and may even, as I said, be inversely associated with stroke.

If I could sum it up in three words, it’s “eat real food” basically.

Dr. Hyman: Right. Very few steps from the field to the fork is what I would say.

Chris: As few as possible and within that there’s a lot of room for individual variation, whether you’re pegan or paleo or what I call paleo template, which means you eat mostly paleo but you have some grains and legumes if you tolerate them well.

Dr. Hyman: And paleo doesn’t mean eating like three pounds of steak every day.

Chris: Absolutely. We go out to eat and we eat almost the same thing.

Dr. Hyman: Exactly.

Chris: You call it whatever you want.

Dr. Hyman: We do pretty good. We’re like pretty skinny guys.

Chris: We’re doing all right.

Dr. Hyman: It’s working out.

Chris: Yeah, I think we can get a little too focused on the details and lose sight of the most important thing which is the quality of food we’re eating. Not the quantity of fat or the quantity of carbohydrate or even necessarily the quantity of protein which we get so obsessed with, but the quality of the foods we’re eating and their nutrient density I think is by far the most important factor.

Dr. Hyman: Yeah, and quality matters. If you eat food that is nutrient dense, your cravings go away.

Chris: Yeah.


Dr. Hyman: People who have iron deficiency will eat dirt to try to get the iron. People who are obese are often very malnourished, and they’re trying to eat more to get the nutrients that they’re missing. So when you actually eat nutrient-dense food, you don’t have all these cravings. You don’t feel hungry all the time. Your brain can turn off, and you literally can get your body back. It’s like basically the body snatchers have taken their bodies.

Chris: This is why it works so well for weight loss. You’re maximizing nutrient density. You’re minimizing calorie density. High protein foods don’t tend to be very calorie dense. Non-starchy vegetables, they’re nutrient dense but not calorie dense. And even starches like sweet potatoes are nutrient dense and not particularly calorie dense. A large sweet potato only has about 35 grams of carbohydrate. That’s not a lot for an active person.

Dr. Hyman: Although fat is pretty calorie dense, but it also works differently in the body.

Chris: But it has key nutrients that are hard to get in other foods. So fat isn’t nutrient dense compared to like beef liver, for example, but it is rich in things that we need and that aren’t found in other foods. And it’s also a great source of energy for the body.

Dr. Hyman: So good. This has been such a great conversation, Chris.

Chris: I always enjoy it.

Dr. Hyman: So tell me what are you working on next and what are you excited about? Because I know you’re working on some great stuff and I want to hear about it.

Chris: So my passion right now is training the next generation of functional medicine clinicians that have an ancestral evolutionary perspective. Because as I’ve said, I believe in the marriage and intersection of these two things. And I think they’re both really powerful on their own, but when you combine them together it’s just incredible what can happen. My practice has mostly been closed to new patients for the last four or five years now. I know you know what that’s like.

Dr. Hyman: We have 2000 people on our waiting list.

Chris: Exactly. And it just became clear to me that there’s no way that I’m going to be able to serve the number of people that need to be helped and people need help. So I launched the Kresser Institute for Functional and Evolutionary Medicine last year, and we have our first cohort going through


there of 200 doctors and other healthcare professionals. They’re about eight months through a 12-month program, and our next enrollment is starting in September. So I’m excited about that.

Dr. Hyman: So great. It’s so great. You’re addressing real issues, and I get emails all the time from friends of mine and colleagues who are doing functional medicine, “Do you know a doctor? I want to hire somebody.” And I’m like, “There’s a few of us out there, but the demand far exceeds the supply.” I don’t know if you know this, but we have almost 100,000 hits every month, unique hits every month on the functional medicine website, looking for a functional medicine doctor. Like functionalmedicine.org, find a practitioner. It’s overwhelming.

We have about 500 certified functional medicine doctors at the Institute for Functional Medicine, and we’re starting to collaborate to work together on more things. And I think that this is really the future. We have to train people up. We have to train health coaches.

Chris: Absolutely.

Dr. Hyman: We’ve got the Functional Medicine Coaching Academy which we’re partnering with, so we’re really bringing everybody into the tent and actually working together to train up the next generation. And also, the truth is—you and I know this, Chris, from your book and my books—when people do this approach themselves, they often don’t need to go see a doctor.

Chris: Absolutely. I would love to put myself out of business if I could.

Dr. Hyman: It’s actually how powerful this is. When you apply the basics, often all these other problems go away. I don’t know if you know Henri Roca. He’s a functional medicine doc. He works at the VA Louisiana chronic pain. He has a little program there where you don’t even see the doctor.

Chris: Right.

Dr. Hyman: The first eight weeks is a coaching program. The next six months is a lifestyle training program. And after six months, if you’re still having problems, then you can go see the doctor, and most of the people don’t even need it.

Chris: That’s actually how we do it. I have my staff do an initial consult on the phone, and then they get the dietary guidelines. And it’s eight to 12 weeks before they actually see me. This was when I was accepting new patients, and a lot of times people would show up and they’d be like, “Uh…”


Dr. Hyman: I’m better.

Chris: “What now?”

Dr. Hyman: I know. I have the same experience.

Chris: It’s amazing what diet and lifestyle change alone can do.

Dr. Hyman: Thank you, Chris, for your work and for digging into the science for us, for doing your blog, for doing your podcast, for creating the Kresser Institute, and doing the hard work. It is hard work to do this, to synthesize all this information and make the difference you’re making.

Chris: Thank you, Mark. You’ve been an inspiration. I’m following in your footsteps, riding on your coattails.

Dr. Hyman: I encourage everybody to get on ChrisKresser.com. Sign up for his newsletter. It’s awesome, so thank you, Chris. And I’ll see you all later.

Chris: Thank you. It’s a pleasure.

hey, everybody. it’s dr. mark hyman. welcome back to the...

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