Why Lifestyle Advice is BS: The Mediterranean Diet Edition

The Mediterranean diet has become medical gospel—promoted by diabetes organizations, heart health foundations, and doctors worldwide. But when I looked at the actual evidence, I found something shocking: the one major study proving its benefits was so flawed it had to be retracted. And when NICE updated their cardiovascular disease guidelines in 2023, they admitted there was "no available evidence" comparing dietary interventions to normal diets, so they made recommendations based on "clinical experience and expert opinion" instead. 

In this episode, I expose how decades of lifestyle advice rest on a foundation of observational studies that can't prove causation, one retracted trial, and guidelines that openly admit the evidence doesn't exist. I explore why we ignored Japan despite identical findings, how the Mediterranean diet reflects Eurocentric superiority rather than scientific rigor, and why telling Black, brown, and indigenous communities to abandon their cultural foods for olive oil is racist as f*ck. The evidence doesn't support what we're being told and it's time we started demanding better.

Ge, Long, Behnam Sadeghirad, Geoff D. C. Ball, et al. ‘Comparison of Dietary Macronutrient Patterns of 14 Popular Named Dietary Programmes for Weight and Cardiovascular Risk Factor Reduction in Adults: Systematic Review and Network Meta-Analysis of Randomised Trials’. The BMJ 369 (April 2020): m696. https://doi.org/10.1136/bmj.m696.

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Transcript

Hello, and welcome to Episode 8 of Season 6 of the Fat Doctor Podcast. I am your host, Dr. Asher Larmie, GP, fatty, and just fed up, pissed off, I guess, is the best way to describe me at the moment. I'm a weight-inclusive doctor who is really trying to dispel some of the myths about weight loss, and I'm doing it through my upcoming book and through the many resources that I have on my website and back on social media, much to my chagrin, on Facebook and Instagram. And boy, people really have a lot to say at the moment.

So I thought what I'd do is I would do a podcast episode to really piss them off. And yeah, this is all about lifestyle advice and the promise that if you change your diet, you can prevent disease. It's actually not specifically about weight loss today, folks. I'm not going to be focusing on weight loss. This is about lifestyle advice in general. We're going to be looking at the Mediterranean diet, and we're going to be asking the question: does following the Mediterranean diet actually prevent illness? Prevent heart disease and cancer and all the other things that we're told that it will do? What does the evidence actually say? So let's just get into it.

You've probably heard about the Mediterranean diet. It's one of the most popular diets out there. There are plenty of other diets out there, like keto and paleo, and if you're RFK Jr., you know it's all about the carnivore diet and fermenting stuff and meat. Maybe not go there. But the Mediterranean diet is quite popular amongst health professionals. And if you go on, you know, Diabetes UK, the American Diabetes Association, if you go on any kind of organization that promotes heart health or cancer prevention or anything like that, somewhere on those websites you will find the Mediterranean diet. It's a fairly well-beloved diet amongst healthcare professionals.

That's great. You know, we talk about like the healthy oils and your omega-3s and your olive oils and your nuts. And nowadays we add in an avocado. We didn't used to say avocados because they weren't Mediterranean, but now we'll add an avocado in there as well. Fish and seafood and plenty of fresh fruit and vegetables. Actually, the Mediterranean diet is predominantly carbohydrates, but we don't talk about that as much anymore. Wine with a meal, no other alcohol, only occasional sweet treats. That's the Mediterranean diet in a nutshell. There's a pyramid that kind of came out. Well, I'm getting ahead of myself. I do beg your pardon. Let's start at the beginning, shall we?

So where does this whole Mediterranean diet come from? We have this idea that Mediterranean diets are the right lifestyle advice, and that's what the GP, the endocrinologist, the nurse, the midwife, whatever, is going to advise you to do. Follow the Mediterranean diet. So where does it come from?

It started in the 1950s with a man named Ancel Keys. You may have heard of Ancel Keys. I talk about him quite a lot. He is the reason that we have the Body Mass Index. In fact, the Body Mass Index exists as part of Ancel Keys' greatest works. He is also the lead researcher for the Minnesota Semi-Starvation Experiments from the 1940s, so he's quite well known amongst us who are interested in fat history, because he personally is responsible for a lot of the shit that we get nowadays. All thanks to Ancel and his Seven Countries Study, which was started in the 1950s and basically found that certain populations had less heart disease than others, and this was specifically the case in Crete, Greece, and Japan.

From his study, we sort of ignored Japan. It was the 1950s, there was some history, and we just put Japan to one side and we focused on Crete and Greece and Mediterranean diets. And in 1975, Ancel Keys and his wife Margaret literally released the first Mediterranean diet book. In 1972, Ancel Keys introduced us to the Body Mass Index, and in 1975 he brought out the Mediterranean Diet Book. And he started it all.

Around the 1980s and 90s, so he sort of did this all in the 70s, and in the 80s and 90s there was very much a low-fat diet dogma, right? All the doctors were: don't eat fat, fat is bad for you, cut as much fat out of your diet. And you know, they were saying don't eat eggs because eggs are high in cholesterol. Nowadays we know that's not true, but that was what we were saying to people in the 1980s and 90s. And that's because, well, we knew that fatty buildups in the arteries cause heart disease, so we assumed that fat in the diet must be causing the fatty buildups in the arteries. We're sometimes very basic, very simple. We don't think outside the box. We're very literal. We're like, oh, there's fat in the artery, that must be because you ate too much fat. So that was very much the dogma at the time.

But in the mid-1990s, and I'm really curious to know who funded this. I have a theory that it was the olive oil industry. I don't know if there is like an olive oil industry. I don't know if the olive oil industry is the same as like Big Pharma or like, you know, life insurance companies. I don't know that it has the same kind of industrial complex feel to it. Like I'm trying to imagine like the CEOs of like olive oil companies, you know, getting together to like secretly fund this PR campaign. It's possible, though. I don't know. I think it's possible, but I haven't researched, so I couldn't say for sure.

But in the mid-90s there was a collaboration of a lot of people who were very pro-Mediterranean diet, and they kind of offered this counter-narrative. So instead of low fat, try Mediterranean instead. Try this new thing. And they published this pyramid, I think it was in the Journal of Clinical Nutrition or something, some journal, in the mid-90s. And then over time that's been replaced. And it's probably familiar to you. At the top of the pyramid are the things you're not supposed to eat, which is like red meat and sweet things. And then in the middle of the pyramid it's things like seafood and fish and poultry and dairy. And then at the bottom of the pyramid is like your vegetables and your carbs, which you're supposed to eat lots of.

But then it kind of got a bit like, we sort of tried to ignore the carbs bit because we're in this kind of very low-carb mentality now, so we're kind of ignoring the very base of our pyramid is kind of no longer something that we're too enthusiastic about. But that was the pyramid, and we began to see it everywhere, wherever we looked, you know, this pyramid.

There's only one study, really, proper study that looked at whether Mediterranean diet actually prevented disease. One major randomized control study, and that was the PREDIMED. And it's, I believe, a Spanish, like it stands for something Spanish, so I'm not going to attempt to tell you what it stands for. But PREDIMED was the study. It was released in 2013, had mass media coverage. Everyone was enthralled. We were convinced: Mediterranean diet prevents heart disease, prevents cancer, prevents this, prevents that. We were like, that's it, we're sold.

Five years later they had to retract the study because it turns out there were fatal flaws with their methodology. Really problematic stuff. So the randomized part of the randomized controlled trial didn't happen. If you're not randomizing, not really, it's not an RCT. Well, it's by definition not an RCT. So they had to retract the study. Interestingly, very minimal media coverage, alright? Because by this point in time we were all obsessed with the Mediterranean diet. It was republished, I think the same year that it was retracted, with the same conclusions but with slightly different numbers. Didn't seem to matter, is what I'm saying. But there's only one RCT.

So this is where I really want to get into how we interpret evidence. I've done podcasts like this in the past. I find it hard to get my head around, so I can understand why other people find it hard to. There is no question that people in certain parts of the Mediterranean have lower incidence of heart disease. Also people in Japan. Also could be people in lots of other countries we didn't bother to study because the Seven Countries Study was seven countries, right? Like he picked seven.

And what's more interesting is now when we look at the epidemiological studies and data, we find that, for example, southern Italy, Crete, much lower incidence than northern Italy. When we look at Greece and Turkey, it's mainly on the coast. So it's not, you know, parts of France, specific parts of France where they have much lower incidence of heart disease, but not all of France. But that being said, there is definitely evidence that people in the Mediterranean have lower incidence of heart disease, alright? No one's disputing that.

But let's just think for a moment: what could explain that? It could be that they have a diet, you know, high in olive oil and all that stuff. It could be. But it could also just be Mediterranean populations, they don't just eat differently, right? They live differently. It could be because they walk more, or they have closer communities, or they have different work-life balance, or they have more sunshine and more vitamin D, or you know, like they have siestas in the middle of the day, they don't, driving cars, I don't know. Like there's so many different reasons why people in the Mediterranean might have a lower incidence of heart disease. I'm just making some up, but all of these things apply.

They could have different access to healthcare. They could have different levels of like community, and we know that social isolation and loneliness absolutely contribute to heart disease. So it could be the community feeling. It could be access to healthcare. It could be pollution, right? Pollution is definitely a part of it. Environmental factors. You could go on and on and on.

So when you observe Mediterranean people are healthier, right? In general, that's actually a generalization. But when you observe that people in Crete, Greece, and Japan are healthier, what you're observing is that everything about living in these countries is making them healthier. You can't pick certain bits. You can't just be like, oh, it's the diet, but it's not the other bits. You can't assume it's the olive oil, folks. Like you're observing everything about that population. That's the whole point of an observational study. You're observing everything about the population, and it's just an observation.

Again, we talked about this last week: correlation versus causation, association versus causation. If it was just the Mediterranean diet, right? If that's the reason why people in Crete and Greece were living longer and weren't getting as much heart disease, then theoretically speaking we could take that Mediterranean diet and we could feed it to people in inner cities in, you know, countries like the UK and the US and Australia, and you would expect to see the same results. Because you shouldn't need to move these individuals to Crete. You should just be changing their meals, and that should be enough if it's just the diet.

Like if you've left them in their inner city urban life, the same weather, the same stress, the same commute, the same air quality, the same levels of social isolation, but you've changed their diet and their heart health improved, then we can say without a shadow of a doubt, yeah, the Mediterranean diet does prevent heart disease. Otherwise we don't know. We don't know.

I'll give you another analogy, right? If you observe smokers, you'll notice that they carry around lighters, right? Well, I don't carry around a lighter because I don't smoke, but smokers tend to carry around lighters. It makes sense. So does this mean that lighters cause lung cancer?

We're not stupid. We know that the reason that people who carry around lighters are more likely to have lung cancer is because they smoke. We understand that smoking is the underlying factor at play here. So what would happen if you said, alright, so what we'll do is to reduce levels of lung cancer, we'll take away the lighters. We'll ban lighters, or we'll recommend that smokers don't carry lighters around with them, or whatever. Like I don't know, like we just ban lighters. That's the key. We're going to fix it by getting rid of the lighters.

Are you going to accomplish anything? Not really. To be fair, maybe to some degree, to begin with, if I'm a smoker and I'm no longer allowed to carry around a lighter, I'm not going to be able to smoke as much, right? How will I light my cigarette? But over time I'm going to find a solution to the problem. If I want to smoke, I'm going to smoke. I'll find a way around. I'll use matches. I'll bum a light off someone else. I'll create, you know, a prison lighter. I don't know. There are so many different ways that I could get around the situation. Getting rid of lighters isn't a solution to lung cancer. It's not going to make any difference on lung cancer rates. Otherwise we'd be recommending it, right? It doesn't work.

So that's what I'm saying. Just because you observe something about a particular population doesn't mean that altering that thing is somehow going to fix the situation. And so the same applies to the Mediterranean diet.

Here's what you have to understand about this population. So say you have a study, like the Seven Countries Study. Actually, let's move on beyond that. Now we take a group of people and we conduct either a retrospective study, so we look back in time. We look at a group of people who had a heart attack, say, and we say, over the last 20 years have you followed a Mediterranean diet? And we find that people who followed a Mediterranean diet are far less likely to have a heart attack than those who didn't. That's a retrospective study. Or we take a group of people and we follow them over a period of 10 years, and we see, like, what's your diet like? And those who adhere to a Mediterranean diet end up with fewer heart attacks. That's a prospective study. That's going into the future as opposed to a retrospective study that goes into the past. Say we took a group of people on the Mediterranean diet and compared them with a group of people who are not on the Mediterranean diet. But these are observational studies. We're not intervening.

An interventional study is when we take a group of people and we put them on separate diets and we do it randomly. One person goes on a low-fat diet, one person goes on a Mediterranean diet. That's separate. That's a randomized controlled trial. We're going to look at that in a minute. I'm just talking about observational studies now.

So if we have an observational study that finds that people who follow a strict Mediterranean diet have a lower rate of heart disease, how do we explain that? What is it about this Mediterranean diet that suddenly, you know, is reducing their rates of heart disease? It could be lots of things, but one of the things you have to really understand is that the people who carefully follow a structured dietary pattern are by definition different, right?

They almost certainly have more money to spend on food, because, you know, if they're following, they're adhering to a strict diet that's high in like olive oil. Olive oil is fucking expensive. So they've got money, right? They've probably got more time, especially if they're making all of their food from scratch. They've got more money, they've got more time. And if that's the case, there's a good chance that they experience less stress. And that could explain why people who are adhering to this diet have lower rates of heart disease, just because of their general kind of social advantage.

People who follow structured diets, who adhere to medical advice, tend to be more engaged with health promotion in general. If you follow a strict diet, chances are you also attend your cancer screenings and your blood pressure screenings, and you're more likely to engage with healthcare professionals. If you're following advice from a doctor, chances are you're engaging with doctors. A lot of people who are stigmatized don't engage with doctors. It's actually the people who tend to follow diets tend to be more engaged with health promotion. They're more likely to take medications. They're more likely to see doctors regularly. They're more likely to avoid smoking. So the adherence to the diet actually is the marker of a person who does healthy things, in quotation marks.

The question isn't whether Mediterranean diet followers have less heart disease or cancer, because they do. We know this. The question is whether the diet causes that, or whether there are other differences between the groups that could explain it. Do you see where I'm coming from here?

So to claim that eating a Mediterranean diet reduces heart disease, we need a randomized controlled trial. We need to take a group of random people, and we need to either put them on a Mediterranean diet or put them into the placebo group or the control group, which is either not on any diet at all or on a different kind of diet. Ideally not on any diet at all, but sometimes it might be like they're on a low-fat diet, so we're comparing the Mediterranean diet with a low-fat diet, which is exactly what I said. There's one study, the PREDIMED study, and they compared low-fat, which is where the problems lay, to Mediterranean diets with or without nuts.

Observational studies, let me tell you, they found yes, some degree of reduction in heart disease rates. A relative reduction. So say 20%, 30%. However, if you look at the actual numbers, how many people had, you know, how many fewer heart attacks were there, it was very small numbers. It was very small numbers because the majority of people in this study were not at particularly high risk anyway.

And that's the other thing. Like I can tell you, I've said this before, I can say to you, oh, this particular diet reduces your risk of heart disease by 25%. But if your risk of heart disease is only 2%, then reducing it by 25% means nothing in the grand scheme of things. If your risk of heart disease is 10%, reducing it by 25% really doesn't mean much. You went from 10% to 7.5%. Like that's not big numbers. And that's almost always the case in these studies. So yeah, there were some relative risk reductions, but they were not absolute risk reductions. The numbers needed to treat were not impressive at all.

And that's before you take into consideration that this one and only randomized controlled trial was also fatally flawed, methodologically flawed. Like I can't believe we still talk about it. To this day we're still talking about it like it was a thing, right? When a study gets published and then a few years later they go, you lied in your study, usually the study gets retracted and we move on. But no, we're still talking about it like it's a thing.

So I went and found a really good meta-analysis from the British Medical Journal. I think it was 2024. That was recent anyway. They looked at 121 randomized controlled trials. That was over 22,000 participants basically in total. They looked at 14 named diets plus low carb, low fat, and compared that to like usual diet. They were interested in blood pressure, in cholesterol, in CRP, which is a marker of inflammation, and in weight.

And what they found was that at 6 months there were some very modest blood pressure reductions with several of the programs. So as I said, there were 14 named diets. Mediterranean was one of them. A small but very modest reduction in blood pressure of about 3 to 5 millimeters of mercury in the first 6 months. The Mediterranean diet showed a significant reduction in LDL cholesterol at 6 months. There was no improvement in markers of inflammation in CRP. There was a reduction in weight, but a very modest one at that. Actually, no, I'm not even sure there was a reduction in weight to be honest. I think I might be exaggerating that. But we were not talking about weight. Remember I said we're not talking about weight loss today, so that's not relevant. We're just talking about health.

So all things considered, you know, that's not very impressive. Like I wouldn't call that a marker of success. But the reality check comes at 12 months when all of the benefits disappeared. That was literally what the authors said: effects on weight reduction and improvements in cardiovascular risk factors largely disappear.

So it doesn't work. Lifestyle advice doesn't work. And that's not just one RCT, not one randomized controlled trial. That is 121 randomized controlled trials.

So we know that lifestyle advice doesn't work. How does this translate into our evidence? In 2023, the National Institute for Healthcare and Excellence produced their most updated guidance on cardiovascular disease. And this included lipid modification, or cholesterol lowering. 2023 NICE guidance says: no available evidence comparing the effectiveness of dietary cholesterol strategies, lifestyle advice, with normal diets for adults with and without cardiovascular disease.

That's what they found. No available evidence. There was no evidence that met their inclusion criteria comparing the effectiveness of lifestyle interventions, diets, specifically diets, not exercise. So no evidence comparing any number of diets to like a normal diet for adults, either adults who didn't have heart disease but were trying to prevent heart disease, or adults that had already got heart disease but were trying to prevent progression of heart disease. No evidence.

So the committee updated the recommendations based on their clinical experience and expert opinion. Their clinical experience and expert opinion. Even if they have lots of clinical experience and are experts in cardiovascular disease, which almost certainly they are, right? Otherwise they wouldn't be on the guidelines committee. They only see the people who went on a diet, succeeded in the diet, and then that improved their cholesterol levels. The people who didn't succeed probably didn't go back to them. The people who did succeed but then like that didn't last were discharged from their care. Their clinical experience and expert opinion is massively biased. Massively biased.

Especially the more specialized you are, you've failed to see the vast majority of people out there who are following the Mediterranean diet and having absolutely no impact on their cholesterol whatsoever. You're only seeing the ones in a very controlled environment. So their clinical experience and their expert opinion is massively biased. It's also funded by the weight loss industry and possibly the olive oil industry. I don't know. I don't want to say for sure, but like, you know, big olive oil, not Big Pharma, big olive oil. You never know. Don't know if you can trust them.

I don't want to say it because like I keep thinking of like Palestinians with their olive trees and it makes me really sad. So like buy Palestinian olive oil and, you know, don't give in to big olive oil. Like, you know, buy local, buy from the people on the ground, is what I was going to say. Anyway, I got distracted.

So we have healthcare professionals that are following guidelines that are not built on any evidence. So to be fair, like doctors are lecturing their patients about the Mediterranean diet because they're being told to, because of a set of guidelines that there's no evidence, just based on clinical experience and expert opinion. You are being given advice that you assume is evidence-based when it's not.

There is a huge gap between what we think we know and what we actually know. Think about how this is impacting you. Think about the stress of like believing that there's a certain way to eat correctly and you're falling short of the mark. Oh, I'm not doing enough, and it's my fault, and that's going to mean that I get sick. And if you do get sick, then you blame yourself for getting sick. But also think about the cost. Like I said, olive oil isn't cheap. Neither are omega-3s and, you know, fresh vegetables.

Think about all the people that got excluded. Think about all the cultures specifically that got excluded. Like I said, Japan was one of the seven countries. We didn't have a pyramid based on Japanese food, right? It was the Mediterranean diet. And to this day there are certain large swathes of the population that are being told that their diet isn't healthy. You should eat Mediterranean. This is racist as fuck. Who says their diet isn't healthy?

Did you study it? Did you do a randomized control trial where you compared the Mediterranean diet to the, I don't know, like pick another diet. South American diet. Southeast Asian diet. Did anybody actually do a randomized control trial comparing the two? Fuck no, you didn't.

If you're going to look at certain populations and go, yeah, well, look at those guys, like they just have much higher risk of heart disease, so clearly their diet is wrong, then you have a genuine lack of understanding of how science works and evidence works. That's not how we do it. And yet we punish, in reality we punish certain groups, certain groups more than others. Black, brown, indigenous cultures who have been eating the same way for centuries and millennia are now being told you've got to switch to the Mediterranean diet because that's what's healthier for you. If you don't want to have a heart attack, you need to have a Mediterranean diet. So there's some casual racism.

As I said, it's affecting your bottom line. It affects how much money you're spending on your groceries every week. It affects how you see yourself, how you eat, you know, what you believe about yourself. All of this stuff. And there's just no evidence.

So the next time you're offered dietary advice from your doctor, even if there's no weight loss focus, even if there's no mention of weight loss, it's just dietary advice, you need to remember that there was at best a 6-month window of improvement and then it all disappeared. That the people creating the guidelines have admitted that the evidence doesn't exist and they're going on expert opinion only.

If we don't have evidence that dietary changes prevent disease, you need to ask, we need to ask ourselves, all of us, what business do we have making it a cornerstone of medical advice? Why are doctors giving out nutritional advice? Why are nutritionists giving out advice about disease prevention when there's no evidence that it actually works? What is going on here? How has this become our reality? And what are we going to do to change that reality?

You know, you need to start, we need to, everyone needs to start demanding better from their doctors. If you're going to sit there and lecture me about dietary cholesterol improvements, if you're going to print out some fucking sheet that you got off the internet, or you know, you're going to lecture me about eating more of this oil and less of that oil, and don't eat that bad food, and you're going to tell me that my food choices are wrong and my cultural food is wrong and all of that stuff, if you're going to do that, you best have the evidence to back it up. I want the names of the studies. I want to know what the evidence showed. I want to know how much I can expect my blood pressure to improve. How long my cholesterols will be lowered. What did the study show? Which studies compared two different diets? Do you have a single study that compares this diet to that diet? Any evidence that it works?

And if they say the guidelines, just go, oh, hang on, hang on a second. That's not good enough. I don't care what the guidelines say. I want the evidence. I want the evidence basis for your actions, because the guidelines will often lie. Or the guidelines will not lie. They'll say we didn't have the evidence, but we made recommendations anyway. So we need to start demanding more from our doctors.

And you know, I don't have it in for the Mediterranean diet. I should point out that like a lot of my family comes from these areas. Not Greece or Crete, but you know, parts of the Mediterranean where we are eating a lot of olive oil and a lot of fresh fruit and all of that stuff. Like it's, you know, the diet they're describing is probably the diet that I eat. But just because I do, because it's how I was raised, because those are the dishes that I grew up on, not because it's superior in any way. And this Eurocentric superiority bullshit, it makes me super, super uncomfortable.

But I don't have a problem with the Mediterranean diet. I have a problem with the doctors that are promoting the Mediterranean diet. I have a problem with the websites belonging to the organizations that we're supposed to trust and get our medical information from. I have a problem with them promoting the Mediterranean diet because they're lying to the general public. They are implying that this is based on evidence when it's not. And we need to be better, I think, at questioning what the evidence actually shows and making our decisions based on that.

That is the very epitome of autonomy. If I want to consent to something, I need to have the right information. I need to have the evidence before I can make an informed choice. And so doctors aren't going to do it. They're not going to do it for you. You have to demand it from them.

So yeah, I'll link the paper that I was talking about into the show notes. I will put it in the YouTube description, and so the people who get upset with me can go to the actual study and get upset with the study. Don't shoot the messenger. I'm just telling you what the study said.

And next week we're going to be talking about a concept called disease mongering and how that has impacted us as fat people. I look forward to sharing it with you. Don't forget, all of the stuff about the Mediterranean diet and lifestyle advice is part of Chapter 3 of my book, No Weigh. And if you just listen a little bit longer, you can find out how you can join my book club and let me read the chapter to you out loud, like soothingly and lovingly, and then we'll have a discussion about what you thought and you can ask me any questions. It's exclusive to members of the Weighting Room. And yeah, it's been a pleasure. As always, take care of yourself. I'll see you next week. Bye bye!