Fat, cancer, and the 1 in 20 lie

 Cancer Research UK calls being fat the second biggest cause of cancer in the UK. It's a claim built on manipulated statistics, false assumptions, and funding from the weight loss industry - and it's actively killing people. In this episode, I show why the evidence for weight and cancer doesn't come close to the evidence for smoking, why population attributable fractions are a chocolate teapot, and why the breast cancer data is far more complicated than anyone is letting on. If you've ever been told your cancer risk is your own fault, this one's for you. 

The study on weight stigma as a barrier to cancer screening: Amy NK, Aalborg A, Lyons P, Keranen L. Barriers to routine gynecological cancer screening for White and African-American obese women. Int J Obes. 2006;30(1):147-155. 

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Transcript

Hello, and welcome to Episode 10 of Season 6 of the Fat Doctor Podcast. I am your host, Dr. Asher Larmie.

I am getting ready to record a series of three podcasts on today, which is World Obesity Day. Not my favourite day of the year. I have heard rumours that some fat liberationists have also named today International Fat Liberation Day, which is fantastic. I love that. The counterpoint to World Obesity Day, a day that was created by the World Obesity Federation — an organisation that I will be talking about sometime later on in the season.

By the time you listen to this, it'll be several weeks in the past, but if you have found that you were inundated with news articles, podcasts, radio programmes, social media posts, and all sorts about being fat, and you're wondering what the fuck is going on — why has it got so much worse all of a sudden? — the reason is World Obesity Day. The World Obesity Federation put out a report about children, because of course it's all about Save the Children now, and lots of PR campaigns followed, with reputable newspapers picking up on these campaigns and basically reciting everything that the Federation — which makes me think of Star Trek — has to say.

Terrible times. And as I'm writing the book and doing some deep-dive research into how the weight loss industry pays for this kind of marketing and branding — how do they get away with it, what do they do? — the more I go in search of the money, and it's not easy to find, the more I realise just how sinister, but also how planned out it is. Like, there's a fucking playbook. They know exactly what they're doing. And there is absolutely no accountability whatsoever. Even when organisations try to hold the weight loss industry to account — especially drug companies, especially Eli Lilly and Novo Nordisk, who are responsible for a great deal of this nonsense — even when they're held to account for unethical practice, most times there's not enough proof, and even if there is, they get a slap on the wrist. Nothing actually happens. So we are being actively harmed by this industrial complex that has no checks and balances, no accountability. It's just allowed to happen. And it's destroying us.

Today I'm going to talk about cancer — so a bit of a content warning there. In fact, the next few episodes will have a content warning. If you have cancer, or know somebody close to you who is going through cancer right now, you might want to skip this episode. I'm going to be bringing the facts and hopefully validating people, but I appreciate it's not the easiest conversation. It's also something I haven't been through personally, although I lost my mum to cancer, so I have some personal experience. But I have no idea what it's like to be given a diagnosis of cancer and then to be told it's your fault because you're fat. And that's what's happening.

So I'm going to be talking about cancer, the narrative around weight and cancer that has really appeared in the last decade, and I'm going to be telling you why this is happening, whether it's true, and what you can do about it.

First things first — there is a really brilliant study, which I will link in the show notes, that looked at over 500 people in the US. It was a study of females of all sizes, with no BMI cut-off, so they actively tried to get as diverse a sample as possible in terms of size, race, and background. They were asking questions about cancer screening, and what they found was: the heavier you were, the more likely you were to delay cancer screening. Over 90% of the sample were insured, so access wasn't the problem. The real barriers were disrespectful treatment, embarrassment at being weighed during procedures, negative provider attitudes, unsolicited weight loss advice — you know, nobody wants to have their breasts squeezed and at the same time be told they're really fat — and medical equipment that was too small to be functional.

All of these things came up as reasons why people were delaying cancer screening, in spite of the fact that the majority of the same sample said they were moderately or very concerned about their cancer symptoms. They knew the risks. They weren't skipping screening out of ignorance or laziness — they were actively avoiding the humiliation, actively avoiding the stigma. So when I say weight stigma kills people, I am not being hyperbolic. I am not making it up. I am being literal. Weight stigma kills people. In order to avoid humiliation, people are delaying or cancelling cancer screening. And that's a problem.

Now, at the same time. If you live in the UK, you'll remember this. If you live outside the UK, allow me to paint you a picture. I think it was 2018 or 2019. There was a campaign by an organisation called Cancer Research UK. It is one of the leading cancer charities, not just in the UK but internationally. It's hugely platformed around the world, and of course we're supposed to trust them implicitly — they're literally fighting cancer. They had this campaign, and you won't forget it if you were exposed to it. It was basically an image of a cigarette packet, and instead of being full of cigarettes, it was full of french fries. And instead of a normal cigarette brand, it had the name "obesity" on it. And the question was something along the lines of: guess what is the second most common cause of cancer?

That was really upsetting. It was all kinds of offensive, and it was meant to invoke a visceral response.

Here's the thing. Cancer Research UK has received millions of pounds of funding over the years from an organisation called Slimming World — a weight management company very similar to Weight Watchers, and probably the most popular weight management company in the UK. I'm talking around £25 million over the last decade or so. And of course, healthcare experts and public health experts were very concerned about this campaign, saying there was a conflict of interest — you're getting money from Slimming World, and then you've got this big campaign. Cancer Research UK said one had nothing to do with the other. And of course it's impossible to prove. That's why there are no checks and balances. They could just say that, and that was the end of it.

The campaign stayed up. And to this day, if you go to Cancer Research UK's website, there is an entire page dedicated to the O-word. It says overweight and obesity is the second biggest cause of cancer in the UK, causing more than 1 in 20 cases. Causing. Really? You are claiming that being fat causes cancer. That's a bold statement. And it's also one big, giant fucking lie. There is no evidence of causation.

Let's look at smoking. I think it's fair to say that smoking causes cancer. We know there is a dose-response relationship — the more you smoke, the higher your risk. There are established biological mechanisms linking smoking to cancer. And we know that if you stop smoking, you reduce your risk of cancer. We've seen this across populations and in individuals. There is really no doubt that smoking causes cancer.

We don't have any of this for weight. We have observations that certain cancers — not all cancers, but certain cancers — are more common in fat people than in non-fat people. There's no dose-response relationship. There are no established biological mechanisms — they try, they come up with theories, but none are established or proven. There's no evidence that reducing your weight reduces the risk of cancer, treats cancer, or prevents recurrence.

The evidence is not comparable. The only reason weight gets a special mention is because it's common. And if you're a weight loss organisation or drug company and you want to make money selling weight loss, tell people they're going to get cancer. Nobody wants to get cancer — it's one of our biggest fears. So of course it's a great way to sell your wares.

I find this webpage so offensive because it's not true. And you know what they don't talk about? UV radiation. Infections. Occupational hazards. Alcohol. All of these things have a much stronger case for being preventable causes of cancer. If you want to prevent melanoma, UV protection is fairly well established — stay out of the midday sun, use sunscreen. But you don't see that on their website. There's no big campaign for sunscreen, because there's no money in it.

It's the same with infections. There is an HPV vaccine that is going to prevent this younger generation from contracting HPV and going on to develop cervical cancer. I think it's around 95% of cervical cancers that are caused by HPV — it's miraculous that we're going to all but eradicate cervical cancer with a vaccination. Infections are linked to all sorts of cancers — hepatitis, all sorts. Why don't we talk about that? These things are preventable, and relatively easily preventable, not just with vaccinations but with safe sex practices. But we're not bombarded with billboards at train stations talking about sunscreen or the HPV vaccine — and we should be, because these are really meaningful ways to reduce our risk of cancer.

There's no money in that. You have to spend money to get people screened, but you make money by selling weight loss.

I can't begin to explain how problematic the calculations are. Where does the 1 in 20 figure come from? I'm not going to go into great detail because it gets technical, but it's based on what we call population attributable fractions — PAF calculations. Great for branding and marketing, not so great for your health and wellbeing. Why? Because population attributable fractions assume, number one, that the association we've observed is causal. We all know association is not the same as causation, but they assume that it is. They assume there are no other factors at play — stress, stigma, weight cycling — all of which could be responsible, but they're ignored completely. And they assume that reducing weight would reduce risk. That's why they call it preventable. None of these assumptions have ever been proven.

And so here we are with the figure of 1 in 20, which has no basis in actual evidence, but is used to threaten, to provoke, and to instil fear in people, so that they will buy into weight loss — purchase the drugs they can only get privately, pay privately for bariatric surgery, whatever. That's what they're counting on.

And here's the thing — the biggest predictor of cancer is age. Age is the biggest predictor of cancer, for obvious reasons. But we never use population attributable fractions to calculate what percentage of cancers are attributable to age, do we? First of all, because it's kind of offensive, and second of all, because you can't sell anti-ageing. Yet. Until that day comes, there's no money in telling people that age predicts cancer, so we don't do it. There's no money in sunscreen, no money in alcohol reduction, no money in vaccinations and cancer screening. That's why it doesn't make the headlines.

We also know, of course, that weight is not a modifiable risk factor any more than age is a modifiable risk factor. Weight loss is unsustainable for the vast majority of people, so it's kind of useless telling people that being fat increases their risk of cancer — even if that were true — when they can't stop being fat any more than they can stop getting older. Logically, we should be talking about weight and cancer the same way we talk about age and cancer. But of course we don't.

A population attributable fraction calculation built on a number of false assumptions is as useful as a chocolate teapot. The minute you pour hot water into it, it's done. It's useless, and it also ruins your tea. So, fuck Cancer Research UK and their 1 in 20 figure. It's just not true.

But if you have cancer — wow. To be told that it's your fault. I know this is the case with many cancers, but I'm going to deep-dive into breast cancer specifically, because it's a common cancer with a lot of available evidence. And how we can start to challenge the narrative here can be applied to a lot of other things.

The narrative is simple: you're more likely to get breast cancer if you're fat, because you produce oestrogen in fat cells, and excess oestrogen increases your risk of breast cancer. That's the narrative. That's what scares people. So let's challenge it. Let's take a closer look.

There is a study called the Million Women Study — a very large study — that found that the higher your BMI in your 60s, the higher your risk of post-menopausal breast cancer. That's what the Million Women Study found. But here's an interesting fact that we never talk about: the higher your BMI at the age of 10 and 20, the lower your risk of post-menopausal breast cancer. So if you were a fat kid and a fat person in your 20s, you are at much lower risk than if you were only fat in your 60s. How does that work? It doesn't make sense.

There was also a meta-analysis of 89 studies that found that fat post-menopausal people had a 39% higher risk of receptor-positive breast cancer. But this is just an observation. And when you dig deeper, you find that that increased risk was only in people who had never used HRT. Among HRT users, the risk was significantly smaller — in fact, pretty much uncertain and statistically insignificant. There's also no link between fatness and receptor-negative breast cancer. And in the same study, fat pre-menopausal people — and I'm using the language of the study, noting that people with breasts aren't necessarily women — had a 22% lower risk of receptor-positive breast cancer.

So it's only post-menopausal people who have never been on HRT, with receptor-positive breast cancer, who seem to have an increased risk if they're fat. Everyone else, not so much. That doesn't make sense. With smoking, it's obvious — the more you smoke, the more likely you are to have cancer. The maths isn't mathing here.

If excess fat causes excess oestrogen, which causes cancer, then why does oestrogen-only HRT appear to reduce the risk of breast cancer? It shows us that the relationship between weight and breast cancer is complicated, that it's hormone-dependent, and that we can't really draw the conclusions we've been drawing.

Now, here's some other information about breast cancer, and I'm presenting this neutrally, without judgment. Aside from the observation that higher-weight people are at an increased risk of breast cancer, we also have similar observations that people who have had one child have a 13% reduced risk of breast cancer versus people who've had no children. Two children: 19% reduced risk. Three children: 29% reduced risk. If the first birth was under the age of 20 compared to people who had their first child over 30, there's a 24% difference in risk. And for breastfeeding: for every 12 months that you breastfeed — cumulatively — your risk of breast cancer is reduced by 4.3%, plus 7% for each birth.

So there is evidence that breastfeeding and childbirth reduce the risk of breast cancer. There isn't any evidence that reducing weight reduces the risk of breast cancer.

Now let's think about this logically. When somebody gets diagnosed with breast cancer, does the nurse or doctor turn around and say, "If only you'd had children earlier" or "If only you'd breastfed"? I should hope not. Do we tell teenagers to go out and get pregnant to reduce their risk of breast cancer? I should hope not. Why? Because giving birth is very risky — it comes with all sorts of complications and risks. And it's the same with weight loss. We talk about weight loss like it's some magic thing with absolutely no long-term consequences, when the opposite is true.

Why do we feel so comfortable talking about weight, but not comfortable talking about age, or giving birth, when it comes to cancer risk? We can't tell people when to have children or how to feed them. We can't tell people to be younger or blame them for getting older. And in the same way, we shouldn't be telling people to lose weight. Doctors have no right to tell people when and how to have a family. Why don't we feel the same way about telling people about their weight?

I want to end this episode by saying a few things. First and foremost, if you have cancer — it is not your fault. There is nothing you could have done to prevent it. There is nothing you can do with your weight to prevent recurrence. I have met people who are being told to go on a diet while actively fighting cancer. That is ludicrous. Cancer causes muscles to waste away — we call it cachexia — it reduces appetite, reduces weight, makes you frail, makes it harder to fight the disease. The last thing you want to do is intentionally deprive yourself of nutrition. Please don't do that.

I've met people who were told they had to lose weight or their cancer would recur. There is no evidence that that is the case. Please do not force yourself to starve thinking it will prevent recurrence. I'd love to be able to offer you an alternative — I'd love to tell you, don't lose weight, try this instead, and it will prevent recurrence. I can't. But I can tell you that you are not to blame. That losing weight has never been shown to reduce your risk, to treat your cancer, or to prevent recurrence. And most importantly: you are not to blame.

Part of the fight is a mental one. It takes place up here, in the brain.

For those of you who have been told you're fat and that's why you're at increased risk of cancer and that's why you should lose weight — bullshit. It's a lie. You can turn around and say: take your population attributable fractions and shove them where the sun don't shine. I don't believe you. And you can remind them there is no dose-response relationship, there is no established biological mechanism, and there is no proven risk reduction from weight loss.

And if they bring up a study from 2018, you can tell them to fuck off. I'm covering all of this in the book — it's part of one of the chapters, so you'll be able to refer to that.

If you are a healthcare professional listening to me right now, and at some point you made a person feel that they were to blame for their cancer diagnosis because of their weight — you need to go and atone for that. Find the person. Get on your knees and beg for their forgiveness, because the psychological damage you did in that moment is unforgivable.

That's it for today. Next week we'll be doing something else — I should know what, maybe I'll click a button and find out. I hope you enjoyed today's episode.

Stay tuned for some updated information about my book, coming out soon. I finally got a deadline in place. The autistic part of my brain kept wanting to keep going, keep adding, keep writing, but I had to give myself a deadline. So — I'm going to put it out there: the 22nd of April is the day I plan to make the book available for pre-order. God help me, I've said it now. It's got to be done.

A lot is happening. Those of you who are part of The Weighting Room and have been coming to Book Club — we've been having a whale of a time. It's been so invaluable, your feedback. Every week I'm reading a chapter of my book and opening up the floor for questions and conversation, which has been really lovely. It's a small gathering, which is how I like it. You're welcome to come along — all you have to do is become a member of The Weighting Room. It's a paid community, but it's only £15 a month, and you get a whole bunch of stuff when you join. So if you're enjoying this podcast and you want to know more, and you want to ask questions and be part of the conversation, why not join The Weighting Room? And if you can't wait for the book to come out, please — on the 22nd of April — will you pre-order it? That would really make my life.

Alright, that's me for now. Enjoy the rest of your week, and I'll see you next Wednesday.