BMI part 3- The evidence against BMI- Transcript
Hi, everyone, it’s Ali from Ok2BeFat! And it’s time for some fat activism basics.
In this series of videos, I’ll be talking about BMI, or the body mass index.
If you haven’t watched part 1 & 2 yet, I suggest you go back and watch them now, so we’re all on the same page.
Ready? Great!
This is Part 3. The evidence against BMI.
In this video I will be discussing weight and weight loss. I will also be using the words “obesity” and “overweight” in the context of discussing and quoting scientific studies, even though these are not words I would normally use.
Before we start talking about debunking BMI and the evidence against it, let’s make sure we all have the same definitions.
Epidemiology is the study of how often diseases occur in different groups of people. When we discuss the scientific studies that are supposed to show how many fat people are dying and of what, the scientific field we are talking about epidemiology.
Epidemiologists research fatness by comparing groups of fat people to groups of thin people and cataloging the differences. These studies can give us correlations — show us that two things may be connected — but they can’t show causation, which is that one thing causes another.
Linda Bacon gives a good example of this in Health at Every Size. Her example is that balding men have been shown through epidemiology to have higher rates of heart disease than men who haven’t lost their hair.
Does this mean that the amount of hair on your head protects you from heart disease? It is recommended that bald men get toupees to reduce their risk of heart disease?
Not at all.
Further research showed that higher levels of testosterone may be causing both baldness and heart disease.
So when people talk about these studies, it’s incredibly important to keep in mind that correlation does not equal causation.
Or that because A and B are happening at the same time, that doesn’t mean that A caused B. B could be causing A. Or C and/or D could be causing them both.
And studies that show correlation may not apply to every individual person. Not everyone with high testosterone will lose their hair or have heart disease.
And while there are diseases that are associated with fatness, an association doesn’t prove a cause.
For example, in type 2 diabetes, research shows that the insulin resistance that eventually develops into type 2 diabetes may cause weight gain, not that gaining weight causes insulin resistance.
People like to talk as though simply being fat causes heart disease or diabetes, but there are no diseases that can be attributed simply to fatness. Because there are no diseases that only fat people get that thin people don’t.
In addition, when discussing rates of harm and death of fat people, we must always keep in mind that fat people are pushed into high risk weight loss methods, including medication with harmful or deadly side effects and dangerous and sometimes deadly surgery to mutilate their functional organs.
The cycle of repeatedly gaining and losing weight through yo-yo dieting is very dangerous. Just one instance of losing and then gaining back weight can damage blood vessels and increase the risk of cardiovascular disease.
It’s also important to keep in mind that fat people face significant medical discrimination and that medical personnel have repeatedly shown very high rates of both implicit and explicit anti-fat bias.
I’ve included two examples of the many studies into the issue of rampant fat bias in medical personnel in the sources list, one is called “Implicit anti-fat bias among health professionals: is anyone immune?” by B A Teachman and K D Brownell and the other is “Implicit and Explicit Anti-Fat Bias among a Large Sample of Medical Doctors by BMI, Race/Ethnicity and Gender” by Janice A. Sabin, Maddalena Marini, and Brian A. Nosek.
I also suggest “First, Do No Harm- Real Stories of Fat Prejudice in Health Care”, a series of first hand stories by fat people of the prejudice and harm they face at the hands of the medical profession. You can find a link in the source notes.
When faced with humiliation, scorn, and gatekeeping at the doctors office, many fat people choose not to go. And when they do go, they are often belittled, mocked and denied care.
Any study that discusses the health and mortality rates of fat people that doesn’t take these factors into consideration is basically worthless.
Now that we set up a proper framework, let’s dig into the studies.
In 2005, epidemiologist Katherine Flegal published a study in the Journal of the American Medical Association titled “Excess deaths associated with underweight, overweight, and obesity”.
In this study, she confirmed what Ancel Keys had found in the 1980s, that the risks of premature mortality associated with BMI actually forms a U-shaped curve, indicating increased risk for very underweight people as well as very overweight people.
Additionally, where death rates did go up, it wasn’t by much. In Harriet Brown’s book Body of Truth, Flegal called the differences “pretty tiny”.
This study was met with a complete uproar. The experts insisted there was no way these results could be trusted, that Flegal’s work was poor. They accused her of cherry picking data.
An epidemiologist from the University of Illinois-Chicago, S Jay Olshansky, replied to Flegal’s study with a journal article arguing that rising rates of fatness would shorten overall lifespans by between 2 and 5 years.
This was completely made up, as Olshansky’s co-author, David Allison, would later admit to Scientific American, saying that the prediction was never meant to be portrayed as precise.
That kills me. Why did you have it published then, dude? I guess because fear mongering is profitable?
So Flegal takes a look at the uproar and the criticism and decides to rebut it by spending the next 8 years collecting information about 97 different studies on weight and premature mortality.
The results of this meta-analysis, which was published in 2013 and included results from over 2.88 million people, were exactly the same as the results of the 2005 study.
Being fat does not put a person at greater risk for dying, and even being very fat only increases the chances slightly.
This second study provoked another round of denial and uproar. One of Flegal’s loudest critics has been Walter Willett, a nutritionist and professor at Harvard. He even organized a conference at Harvard solely to attack her work.
Selectively choosing which data to include is Willett’s criticism of Flegal, which is funny since the 2010 study that he published — the one that found early mortality risks the lowest among people with so-called ‘normal’ BMI — that study threw out over 80 percent of the data to get to that status quo upholding result. He deleted anyone who had ever smoked or had any history of cancer or heart disease.
So who picked the cherries here? Exactly?
I guess we’ll never know. Oh look, I’ve died from sarcasm poisoning.
In his book The Obesity Myth, Paul Campos discusses another famous study that is supposed to prove that a higher BMI leads to higher premature mortality.
The Nurse’s Health Study was published in the New England Journal of Medicine under the title “Body Weight and Mortality Among Women”. It followed 115 thousand nurses for 16 years. And although this study is cited constantly as proof that fatness kills, it has major flaws.
For one thing, only 4 thousand 7 hundred women died in this time period out of 115 thousand, or about 4.5% of the group.
This is not a very large number of deaths, and not really a percentage that should allow people to feel confident making sweeping statements about so-called excess weight being a danger to all people everywhere.
98% of this group of nurses was middle-aged, middle-class, white American women.
So maybe the safest thing we can say about this study is that middle class white women have really low overall mortality when they are middle-aged.
We could also safely say that smoking is a serious health hazard, as the death rate was significantly higher among smokers.
Because the thinnest women were nearly twice as likely to smoke as the fattest women, we could perhaps even say that wanting to stay thin is a risk factor for smoking.
A side note —
I am an ex-smoker and I don’t like the demonizing of smokers that you see basically everywhere. So let’s lay off turning people who smoke into demons. Rates of smoking are higher among marginalized groups and quitting is a painful daily agony with very little in the way of support.
Smoking is legitimately bad for you, but so is playing football or driving a car.
I will not turn one group of people into monsters to save another. People are people and we’re all doing the best we can.
So let’s not go there, ok? Great, thank you.
Back to Campos — The authors of the Nurse’s Health Study used percentages in misleading ways.
To give an analogy of the way the data was manipulated, consider this example,
if an overall 2% risk of rain is doubled to 4%, that’s still a quite small chance that it will rain.
You can either report an overall 2% increase in risk, or you can say the risk went up by 200%. Both are factually accurate, but the second one looks much scarier and bigger simply because 200 is a bigger number.
If you take out such manipulations of data, the Nurse’s Health Study actually finds that the women with the lowest risk of death are a lot larger than average.
And yet, the authors of this study claimed that being even mildly overweight is associated with a substantial increase in premature death, a conclusion which their own study does not support.
This disconnect between the data and the conclusions of a study are very common in studies that are supposed to prove negative claims against fat people.
When you take these fatphobic study conclusions, turn them into a press release that you run through the media machine of science reporters who report only screaming headlines, you add more stigma to a world that never stops harming and stigmatizing fat people.
Let’s add a few more studies, a bit more research for the “But Science” crowd, just to make sure we all know that studies debunking BMI and lifespan are very widespread.
In Health at Every Size, Linda Bacon lists the following studies that show that fat people were living as long as, and frequently longer than, so-called normal weight people.
The Established Populations for the Epidemiological Studies of the Elderly investigation which included more than 8 thousand senior citizens.
The Study of Osteoporotic Fractures investigation which included more than 8 thousand women.
The Cardiovascular Health Study which included almost 5 thousand people.
The Women’s Health Initiative Observational Study which included 90 thousand women
A study of almost 170 thousand people in China
A study of 20 thousand German construction workers
A study of 12 thousand Finnish women
A study of 1.7 million Norwegians, which found the lowest life expectancy among those defined by BMI as underweight.
And what has the scientific community done when faced with this research?
They label it a paradox and ignore it. They keep pushing outdated information. They actively work to keep the stigma against fat people in place, a stigma that ruins lives.
Because supporting the status quo is easy. And because that’s how so many of them get paid.
Harriet Brown says in Body of Truth- “I’ve been told by numerous researchers that the easiest way to get a study funded now is to include the word ‘obesity’ in the proposal. Even better, cite ‘childhood obesity’.”
So when faced with the question — why do we keep using BMI as a measurement of health when we know it doesn’t measure health at all? — I think the answer is clear.
BMI does actually do what it’s supposed to do. It’s just that what it is supposed to do has nothing to do with health.
BMI is a way to excuse the bigotry that is fatphobia.
BMI gives fatphobia rules. It makes hating fat people easy and bloodless. It keeps the worst and most deadly discrimination we face — medical discrimination — it keeps that discrimination discreet and private and hard to talk about or to prove.
BMI gives a culture than hates and fears fatness a science-y sounding basis to keep hating and fearing fat people. To keep hating and punishing the fat people that thin people are afraid they are going to become.
BMI makes stigmatizing fat people easy. It uses math and round numbers to put a little distance between the fatphobic person and the fat person they are harming.
BMI makes a fat person into a number, a medical problem, a disease that must be stopped by stripping fat people of our status as people and replacing our humanity with a moral indictment in the form of an equation.
BMI props up the weight loss industry, a harmful and useless industry that extracts $60 billion dollars a year out of the economy of the United States — money that it would not be possible to make without fat stigma. Money that could be put to better use doing almost anything else.
The profits of this agony machine are increased by increasing the pain and fear and deaths of fat people.
BMI makes hatred into math. And people feel comforted in their prejudice by having that math. And some people make obscene amounts of money from it. And so it remains.
But it doesn’t have anything to do with heath and it never did.
And that’s the end of Part 3! And the end of the BMI series.
Please see the notes for a list of the sources I consulted for this series.
If you have specific questions about BMI, leave a comment below!
Always and forever, I have to thank all the fat activists who came before me and those who will come after.
And thank you also to my supporters on Patreon, especially the ones scrolling by now.
You can support my work on Patreon at patreon.com slash Ok2BeFat. Your support helps me continue this work. See you again soon!
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Sources —
Adolphe Quetelet and the Evolution of Body Mass Index (BMI) — by
Beyond BMI — by Jeremy Singer-Vine
http://www.slate.com/articles/health_and_science/science/2009/07/beyond_bmi.html
Commentary: Origins and evolution of body mass index (BMI): continuing saga — by Henry Blackburn and David Jacobs, Jr
https://academic.oup.com/ije/article/43/3/665/2949550/Commentary-Origins-and-evolution-of-body-mass
NIH statement- “Health Implications of Obesity”
https://consensus.nih.gov/1985/1985Obesity049html.htm
Implicit anti-fat bias among health professionals: is anyone immune? — by B A Teachman and K D Brownell
http://www.nature.com/ijo/journal/v25/n10/full/0801745a.html
Implicit and Explicit Anti-Fat Bias among a Large Sample of Medical Doctors by BMI, Race/Ethnicity and Gender — by Janice A. Sabin, Maddalena Marini, and Brian A. Nosek
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0048448
First, Do No Harm- Real Stories of Fat Prejudice in Health Care
https://fathealth.wordpress.com/
The big fat truth — by Virginia Hughes
https://www.nature.com/news/the-big-fat-truth-1.13039
Tobacco Use Among Adults with Mental Illness and Substance Use Disorders
https://www.cdc.gov/tobacco/disparities/mental-illness-substance-use/index.htm
Body of Truth by Harriet Brown
Losing It by Laura Fraser
Big Fat Lies: The Truth about Your Weight and Your Health by Glenn A Gaesser, PhD
The Obesity Myth by Paul Campos
The Great Starvation Experiment by Todd Tucker
Fat History by Peter N. Stearns
Health at Every Size by Linda Bacon, PhD
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