02 | Cooked: All-meat eaters say they feel great – but why?

Mick: That’s lamb leg steaks. We’ve got eggs, which are local eggs we get from a farmer, she drops them off. There’s chicken eggs and some big duck eggs. 

Jenny: We’ve got some homemade biltong there. We make it, it’s just dried meat with a bit of salt in it, that’s it. We have a couple of different varieties of tallow, fat, in there because we use that for cooking.

Emma Beckett: You’re getting a glimpse into a carnivore’s fridge. 

Mick: I see a lot of mince. Mince is pretty common. We do a lot of things with mince.

Jenny: It’s always the go to if you need to defrost something in a hurry and you just make burgers. Mince, salt and an egg in it and you’re done.

Emma Beckett: Mick and Jenny live in the Snowy Mountains region of New South Wales. They’re in their 60s, they used to be chefs, and they have a very particular way of eating. One built around meat.

And the origin of that starts way back. 

Jenny: I got quite large early. In those days, most children were quite slim, but I wasn’t.

Emma Beckett: Jenny had always grappled with her weight.

Jenny: I yo-yoed around in my 20s until I had some fairly major health problems towards the end of my 20s. I was trying to eat well, and I ended up having a cancer and chemotherapy type treatment for a while. It left me with like a chronic fatigue afterwards for several years. Chemo will do that to you.

And then I just decided in 30s that I would stop dieting, trying to lose the weight and just sort of give in.

Emma Beckett: Jenny stayed on that track until 2020. That’s when she decided to try first the ketogenic diet, where you eat a very low carbohydrate and high fat diet, and then carnivore, which restricts what you eat even further. With carnivore, you typically only eat animal products, things like meat and eggs. 

Jenny: For myself, I just eat fresh meat, beef, lamb, I eat some pork and I eat some eggs. I have salt and water.

Emma Beckett: She’s now been a strict carnivore for more than two years. Jenny’s husband Mick also follows a carnivore lifestyle, but his version is a little less strict. 

Mick: I have meats, basically, again, lamb and beef, which are ruminant animals, so that’s the preferred meat usually for people on a carnivore diet.

And I have some pork and some chicken. And I have dairy. I do eat dairy, but it’s always a fermented dairy. 

Emma Beckett: Mick makes his own yogurts, has a bit of fermented vegetables, and …

Mick: In season, if the berries are on the bushes and things, I’ll grab some berries. I was always a fruitaholic, but I seem to have weaned off that now.

Emma Beckett: For Science Friction, welcome back to Cooked, our series here on Radio National about the nuance of nutrition, the foods we eat and how we make sense of them, as you navigate the ever-growing bombardment of diet advice online. I’m food and nutrition scientist Dr. Emma Beckett, and today we’re digging into a meaty mystery.

Diets like carnivore have been popping up all over the place. And they often become a belief system as much as a way of eating. 

Jenny: I like what I eat, and I eat what I like. 

Jacob Mey: When people are particularly passionate about a lifestyle change, quite often it’s because they have a health condition that they want to improve.

Emma Beckett: We’ll hear how and why some people follow an all-meat diet.

Jenny: It’s just a total change from how I’d been.

Emma Beckett: And what we know about the science and psychology of going carnivore. 

Richie Kirwan: You can feel absolutely amazing. But things can be going on in your body that may not show for another 20, 30, 40 years.

Emma Beckett: That’s today on Cooked.

Mick: Whenever we’ve travelled, we’ve always pursued, you know, the interesting foods wherever we’ve been. So if we’ve been backpacking through India, we’d get the Lonely Planet guidebook and find out what all the local specialties were in a particular town or village and hunt them down and try them.

And so we’ve always been very adventurous in that regard. And we’ve enjoyed food. Food’s been a very, very big part of our life. But I guess what we realise now is we now eat to live rather than live to eat. And that’s been the evolution. So as we get older, our bodies need something a little different. If it curtails a little bit of the adventurous food and that sort of stuff, it doesn’t really matter.

We’re enjoying ourselves and much healthier and we’re now, you know, in our 60s and very active. 

Emma Beckett: So what brought this health conscious husband and wife to try carnivore? When you think of the carnivore diet, you might think of toxic masculinity and the alt right. And it’s true that its popularity has been spurred on by some polarising figures, including podcaster Joe Rogan, Jordan Peterson, and a colourful character called the Liver King.

Speaker: Liver King is having liver – surprise, surprise – for dinner today. 

Emma Beckett: But it would be an oversimplification to assume this motivation applies to all carnivores. And it’s not where Mick and Jenny are coming from. Their motivations are more personal. They both experienced health issues that they didn’t feel were resolving with traditional medical approaches.

For Jenny, it was the chronic fatigue she couldn’t shake. And for Mick …

Mick: For the last 30 odd years, I had a lot of joint and muscle issues and inflammation. We had a very active lifestyle. It didn’t stop me from doing it, but it made life pretty hard at times. It used to be very difficult getting out of bed in the morning.

And then the first few steps of the day were pretty painful, which unfortunately the medical profession weren’t able to help me with. I saw a rheumatologist and had lots of the blood markers done and bone scans and various things. No one really seemed to be able to find a cause, but it’s when we went on carnivore, all of a sudden it’s gone.

I now can live a much more normal life in that regard. I can run an ultramarathon, 100 kilometres, 100 miles, and recover really quickly afterwards. It’s just my body’s responded so much better to it. So even though I didn’t start carnivore for that reason, that’s been one of the benefits of following a nutritional lifestyle that I hadn’t been able to achieve on any other diet.

Emma Beckett: For Mick and Jenny, eating an all-meat diet has been life-changing. And this story isn’t unique. Log onto any social media forum for people following a carnivore lifestyle and you’ll see many reports of people who say they feel great eating meat and little else. But this is strange. Because the story goes against everything we know about nutrition and diet.

Large studies of tens of thousands of people consistently link the overconsumption of meat, particularly red meat and processed meat, with negative health outcomes, increased risk of various types of cancer and early death.

It’s easy to dismiss extreme diets from the outside. As a food and nutrition scientist raised on messages of diversity, variety and balance, I find something like carnivore hard to digest. And all-meat diets have been criticised as harmful to the environment and counter to sustainability movements.

But I also feel science should be curious and empathetic. So how can something that the evidence tells us is bad for our health have people feeling so good?

It’s hard to explain this from the research because there’s only been a handful of studies looking at the carnivore diet specifically.

One of the more well-known papers was published in 2021 by a group of researchers out of the United States.

Jacob Mey: The carnivore diet is a unique diet that has popped up just really in popularity in the past couple years. We conducted this study right around the year 2020, right at the turn of the year there.

But it was really the growth and popularity of a largely unknown diet. And we wanted to better characterise the individuals that were consuming this diet and also what the diet was. 

Emma Beckett: Dr. Jacob Mey is an assistant professor at Pennington Biomedical Research Centre in Baton Rouge, Louisiana, and a registered dietitian. He’s one of the co-authors of a study that surveyed more than 2,000 people who identified themselves as following a carnivore diet for at least the past six months. Researchers asked people why they were following the diet …

Jacob Mey: Number one is probably chronic disease. So you can consider that largely your obesity and your diabetes or your metabolic health disorders.

There were a handful of people that reported on other items that we would consider part of your quality of life. Hunger, mental clarity, memory and focus, strength, mobility, those sort of items. But largely the primary drivers appeared to be chronic disease related. In general, you’ll find when people are particularly passionate about a lifestyle change, it’s because they have a health condition that they want to improve, and they find nutrition or a new lifestyle as a way to improve it. That is a very common motivator that we see. 

Emma Beckett: And they were quizzed on what benefits they saw as being linked to going carnivore.

Jacob Mey: Some of the really most startling items that are reported are people are reporting resolutions of their issues with overweight and obesity. So we’re seeing substantial weight loss.

We’re also seeing resolution of metabolic disease. You can consider that insulin resistance. A large percentage of individuals, I believe it was over 80%, that used injectable insulin or exogenous insulin to manage their diabetes ended up coming off that.

Emma Beckett: These findings seem remarkable. 95 per cent of the people surveyed reported they felt better on the carnivore diet.

If you look at that on face value, you’d think that going all meat is a winner. But we can’t take most research in nutrition on face value alone, because while the top-level finding is positive, it comes with a whole heap of caveats. Something Jacob is at pains to emphasise.

For one, when you do survey studies like this, there’s something called survivorship bias.

Jacob Mey: With a study like this, you know, we’re polling people that are self-reporting to consume this diet for an extended period of time. If someone tries a diet for even a couple months, certainly six months, and it’s not working for them, most likely they’re not going to stay on this diet. So we are kind of inherently self-selecting people that are getting positive benefits.

These are really likely only the people that are getting good benefit from the diet that are also participating in this survey. 

Emma Beckett: And the challenge in so many nutrition studies – actually all the sciences that deal with humans – self-reported data.

Jacob Mey: Anytime you have a self-report study and you’re not inherently measuring or requiring some sort of documented research grade or clinical analyses, for example, diagnosis of diabetes or diagnosis of obesity. These are items that theoretically you could get in a clinical research setting, either from medical records or from coming in and conducting those tests. We didn’t do that. We sent this off and asked people to self-report what their items were. 

Emma Beckett: So these findings are best served with a liberal application of salt.

You’re listening to Science Friction with me, Dr. Emma Beckett. And today, as part of Cooked, our series on the nuance of nutrition, we’re looking at all-meat diets. There isn’t much published research on these diets. But we’re digging into one of the few studies that looked into carnivore, and some of the pitfalls you can fall into when reading up on research like this.

Richie Kirwan: If you have a study like this, people are going to use it and they’re going to say, right, I’m going to use this to promote our diet. And we’re going to, like, like I said, people are saying, hey, here’s the evidence. And I want to make sure that whatever is said about nutrition, I like to see that it’s actually truthful and it’s not conflated.

Emma Beckett: This is Dr. Richie Kirwan. He’s a lecturer in nutrition and exercise physiology at Liverpool John Moores University in the UK. And when he saw the carnivore study published in Current Developments in Nutrition, he decided to write a letter of response. 

Richie Kirwan: I felt a little bit of an obligation to kind of put out and say, hold on now, let’s talk about this evidence.

And in absolute fairness to the authors of the paper, they did mention this in their, the limitations of their study at the end, which is really, really good. But I thought it was worth bringing that up and kind of going into a little bit more detail about the limitations of the study and what it can and can’t really tell us.

Emma Beckett: Ritchie says he lurks in multiple online diet groups, from vegan to carnivore, and that in all of them, those who have had the most benefits are the most outspoken. This is pretty common in all online groups for all sorts of diets. Those who find the most benefit speak out with the loudest voice. So selecting people from this group can often lead to a biased sample.

Richie Kirwan: You will see quite a lot of people talking about some of the negative side effects, but these tend to be people who’ve been doing it quite recently, and they tend to get shot down within these groups as well. It’s like, oh, you know, you’re doing something wrong or whatever.

Emma Beckett: If that’s where we recruit people, those are the opinions we’ll get, which is called selection bias.

Richie Kirwan: So again, that’s another potential bias that you see in studies like this. They make the diet a part of their personality. They make it a part of their identity. And when it becomes part of their identity, most people will try to defend their identity as much as possible. 

Emma Beckett: And people who pay attention to their health, to the point of trying a diet like this, they may be more health conscious in other ways, too.

Richie Kirwan: If they’re following a diet particularly strictly. They tend to be people who tend to go all in on everything just to do everything that they possibly can, especially if they’re doing it for health reasons. So within people who are following this diet, they’re not following the diet alone. They might be doing additional things like intermittent fasting.

And actually we saw within the study itself that there were quite a number of individuals who were doing some form of intermittent fasting, you know, two meals a day or even one meal a day. You’d see a lot of people who are high exercisers, they’re potentially modifying their sleep. So they’re getting a lot of sleep, stress reduction, things like that.

It’s not just about diet. You have to bear that in mind as well. Again, take the information with a pinch of salt. 

Emma Beckett: Looking beyond the headlines of the study helps get us more context on what’s going on and explain a little about why it reports such positive findings. But for people like Mick and Jenny and others who’ve gone carnivore and been able to stick to it, we know that in some cases they have lost weight and they say they feel great.

Jenny: My mind cleared. I’m not too bad with my mind, but I’d always had times when I just felt a little down or a little fuzzy, you know, sometimes you’d get a bit fuzzy and I had some headaches during that time and they just cleared completely and my mind just cleared. The energy loss that I’d had, I was just felt low energy and it, really improved afterwards, and I just felt so much better within myself.

Some of it’s just a little hard to describe. It’s just a total change from how I’d been.

Emma Beckett: So how do you explain that? 

Richie Kirwan: You see a lot of individuals in this group who were reporting that they got into it because they had some sort of allergy or autoimmune condition beforehand. They went on this diet, and they saw improvements.

And I genuinely think, for some individuals, going on this diet could be beneficial. And if you think about it, going on a carnivore diet is like a massive elimination diet. 

Emma Beckett: An elimination diet is where you stop eating certain foods to test whether they’re triggering an allergic reaction in you. 

Richie Kirwan: And then you slowly reintroduce different foods, testing them to see what foods somebody tolerates. With the carnivore diet, it’s like an extremely restrictive elimination diet. You’ve eliminated potential allergens from your diet in the form of fruits, vegetables, grains, legumes, all of these different things. And people immediately feel better because all of these are gone from their diet. The only thing is with the carnivore diet, there’s no reintroduction phase at all.

Emma Beckett: And most people don’t have these problems.

Richie Kirwan: Most people don’t have autoimmune conditions, don’t have issues with fruit and vegetables, and they can tolerate them perfectly well. You’ve got this group of people that are saying, Oh, I went on a carnivore diet, I feel amazing, I’ve never felt better in my life.

Everybody should do that. That’s not the case. You can’t make that massive generalisation. And then another thing I’ll say is, there are probably some people within the carnivore community who have suffered with poor health and suffered with body weight, excess adiposity for a long time. They may have tried multiple different diets.

They’ve never been able to, let’s say, shift the weight or anything like that or feel better. And they’ve done this diet. And it’s a very restrictive diet. Let’s be completely honest. It’s very restrictive. There’s only so much meat that you can eat. 

Emma Beckett: Protein is a super-satiating macronutrient. The more you get, the less hungry you feel.

Richie Kirwan: What you’ve got is a massive amount of calorie restriction. People are losing weight for the first time in their life. They feel amazing because of those, those weight loss benefits. So it might be related to joint health. It might be related to their ability to breathe better. All of these things, better glucose control.

These are genuine benefits and we have to, like in the scientific community, we have to appreciate that these people are reaping some benefits here. 

Emma Beckett: But Richie says those same benefits can be achieved with a more balanced diet. And when it comes to the risk of heart disease, he doesn’t mince words.

Richie Kirwan: You can feel absolutely amazing, but things can be going on in your body that may not show for another 20, 30, 40 years.

And that’s particularly the case with cardiovascular disease. 

Emma Beckett: In some forms of heart disease, plaque builds up within our arteries and can cause a blockage. 

Richie Kirwan: And that’s where we get a heart attack, a myocardial infarction. Without care, we usually start seeing the results of those plaques, like things like heart attacks, in people who are 55, 60.

Okay. That takes a long time. You’ve got people in these carnivore communities who have gone from, let’s say they might have gone from a stage where they were suffering from obesity and suddenly they’ve lost loads of weight. They feel fantastic. Their blood sugar control is great, but now their LDL cholesterol has gone sky-high and we know LDL cholesterol is responsible for the development of plaques.

Emma Beckett: A healthy diet isn’t just about visibly losing weight, looking leaner or feeling healthier. It can be linked to risk factors for heaps of diseases and your longevity over a lifetime. 

Richie Kirwan: So these people feel, I feel amazing. Nothing can be wrong with me right now. All the while you’ve got this continuous process of cholesterol building up within your artery walls.

So we have to think about long term health and, like, feeling great is wonderful. Absolutely. Like, you know, everybody wants to feel good. But we have to bear in mind that we need to look at other things that kind of reflect our long-term risk as well. 

Emma Beckett: Richie’s pursuing research right now that will explore more about the risks and benefits of meat-focused diets.

And Jacob encourages that work, which will go beyond the preliminary studies that have been done so far. 

Jacob Mey: I think that’s what comes mainly from this work is the potential benefits about the medications or whatnot. Those really need to be taken in the context of the limitations, which means I hope no one comes away from this session saying: Hey, I should do this diet because I will come off meds and this will happen to me. No, no, no, no, no. We are just describing, hey, this is what successful people on the diet are reporting. We need to do more research, perhaps a randomised controlled trial where you can have the full spectrum. Where’s the positives, where’s the negatives, and what can we then learn?

That’s what this paper was really doing, is it’s saying, hey, this is what’s out there, these are the gaps, where can we go from here? 

Emma Beckett: So, we’ve heard a bit about the evidence around going carnivore, and some of the pitfalls you can fall into when looking at survey data. And we know a little more about why people might feel good following carnivore.

But there’s other motivations for following a diet too, often social and cultural. 

Janet Chrzan: There are forums and all kinds of ways to interact with other people, and so it’s very, very powerful. But it’s also powerful as a way of connection. 

Emma Beckett: Dr. Janet Chrzan is a nutritional anthropologist and author of Anxious Eaters, Why We Fall for Fad Diets.

She’s really interested in understanding the ways we eat as a product of our modern life. According to Janet, there are powerful societal reasons people turn to particular ways of eating. And that doesn’t just apply to carnivore. 

Janet Chrzan: If you are surrounded by people who give you positive feedback: ‘oh dude, you know, you are really taking care of yourself by going paleo.

And, you know, my cousin did that, and he’s really healthy now, and he feels great’. That is this reinforcement that is extraordinarily powerful because it’s not just a reinforcement about your aims and your goals, or maybe allaying your fears, but it’s also a social reinforcement because somebody is in approving of what you’re doing, and that is, you know, the core of what makes us happy as humans.

Emma Beckett: The flip side of that is avoiding negative feedback, too. That’s something Jenny, the carnivore follower from the Snowy Mountains, has found. 

Jenny: At first I just wanted to help other people I suppose, it’s just like I’d found the new way. But obviously other people sometimes don’t want to hear that because they want to stay the same in their lives. And so I quickly learnt to mention it less. 

Emma Beckett: Janet says the choices we make about food are more difficult now than ever. 

Janet Chrzan: The more options people have for what to eat, the more mental effort you have to make, and the more mental static there is, and the more potential anxiety about choosing the right foods.

We’re just inundated when you walk into a supermarket with so many options and so many choices. Many of these diets, the drivers are about not only a perfectible human, but they’re about allaying fears about illness that you might have. And when I talk with people about why they have adopted a particular fad diet, sometimes it starts with, well, I needed to lose 40 pounds, but then very quickly morphs into the medical promises that are made by the adherence of the diet.

But I think that there’s so much narrative right now in the popular speaking about food that’s about fear. That’s about there’s stuff in the food that’s going to hurt you. And so if we go to something that’s really pure, that we will not get hurt and it will potentially even cure some of the things that we’re worried about. And meat is very pure, right? It’s a singular substance. 

Emma Beckett: And that makes the promise of simple rules-based plans for eating very appealing. 

Janet Chrzan: It’s really quite relieving, and it will take away a lot of anxiety if somebody very kindly tells you, oh, no, no, no, the only thing you need to eat is chopped hamburger and the occasional pear.

And you will be perfectly healthy, and you don’t have to worry about that. There’s no more mental static. So I think that’s a really big part of the appeal of fad diets, because they do restrict what you can eat, and they do have very simple reasons for the restriction that make sense.

Jenny: I know what I feel, and my experience has given me that sort of confidence. I just am happy not cooking and not thinking about food these days. What I’ve gained is worth far more than those little bits of food, and I don’t feel the desire to eat those things anymore. I know what they do to me. Even just a small taste will change how I feel. So I just have to abstain. I like what I eat. And I eat what I like.

Emma Beckett: This might work on an individual level, but Janet Chrzan is concerned we lose something on a societal level in following these kinds of dietary rules. 

Janet Chrzan: Eating together is so intrinsically important to us as a species. It’s important to Who we are as people that to adopt a diet that keeps us from doing that, or it makes us explain all the time or makes us avoid food that loved family members offer us that makes it extraordinarily hard to keep with these diets. And so people tend to cycle on and cycle off.

Emma Beckett: Dr. Janet Chrzan from the University of Pennsylvania. You’ve also heard from Jenny and Mick from the Snowy Mountains. Dr. Jacob Mey from the Pennington Biomedical Research Center in Louisiana, and Dr. Richie Kirwan from Liverpool John Moores University. As always, we recommend that you consult your GP for personal health advice.

Thanks to producer Carl Smith, senior producer James Bullen, and sound engineer Angie Grant.

For Science Friction, this has been Cooked. I’m Dr Emma Beckett.