The Decibel - The problems with linking weight and health

Episode Date: February 20, 2025

Body weight often gets conflated with overall health, and the BMI — body mass index — has helped solidify that belief. But in recent years, the measurement has come under increased criticism. Some doctors have started using a new measurement of health called the body roundness index, or BRI.But does BRI address the issues so many have with the BMI? And how do these measurements that tie weight and overall health together impact the experiences of fat people navigating the Canadian healthcare system?Dr. Kelsey Ioannoni is a critical health sociologist and fat studies scholar. She studies weight based politics and discrimination. Dr. Ioannoni joins the show to explain the benefits and drawbacks of BRI, and if it could change people’s experiences in the doctor’s office.Questions? Comments? Ideas? Email us at [e-mail] go here

Drugs used for weight loss, like Ozempic, have affected how we think about body size. Weight often gets tied to health, and that's in part because of the BMI, the Body Mass Index. For years, many doctors have used it to measure health. But the BMI has recently come under a lot of criticism, and so a new measurement is starting to be used instead. The Body Roundness Index, or BRI. Dr. Kelsey Iononi is a sociologist. She studies weight-based politics and discrimination. Today, Dr. Ioannoni will explain what's driving this shift to BRI, the drawbacks of using it, and if it could change people's experiences

in the doctor's office. I'm Maynika Ramen-Wilms, and this is The Decibel from The Globe and Mail. Dr. Ioannoni, thank you so much for being here. Thank you for having me. So before we get into the measurement that may take BMI's place, let's talk a little bit about BMI and just get a sense of what Body Mass Index is, because it's something probably a lot of us are familiar with. But can you give us some of the history of how and why it was created in the first place?

Yeah. So BMI is this really interesting measure when the history of how and why it was created in the first place? Yeah, so BMI is this really interesting measure when we look at how we use it today versus what it was created for. It was actually a population-based measure about 150 years ago by a Belgian mathematician, Adolf Kudelet. He was sitting out to figure out what the average man was like in Western Europe. And this is really different from how we use BMI today, that same measurement of looking at someone's weight in kilograms divided by their height squared in meters. But we use that number now to determine health

or really to apply determinations of health at an individual level, opposed to this population average that he was calculating before. I think it's really really interesting you pointed out the fact that he was a mathematician So this wasn't actually even devised as a start as kind of like, you know a health care practice thing No, absolutely not. He was a mathematician and a statistician and he was looking at like like I said large volumes of European men To see what the average or ideal European man's size was Okay, so how do we use BMI now then? Yeah, I'm sure you yourself and many of your listeners are familiar with going to the doctor and they make the chart or they point on the chart

where your individual BMI is. And they use that as a determinant of health, like what that number tells us about your health charted on underweight, normal, overweight and then into obesity. So currently, if you have a score of a BMI of 25 to 30, you're considered to be overweight. And over 30 puts you in that category of obese. 20 to 25 is about what we consider for normal. AMT – And as you mentioned earlier, so this is determined by dividing your weight in kilograms by the square of your height in meters, and this is supposed to give you this number.

You mentioned the term obese there. We hear that word a lot, but can we kind of define, I guess, what that means? I like to rely on a definition that comes from some critical obesity scholars that are very prominent out of Australia, Dr. Gard and Dr. Wright. They define obesity as excess fat that impairs health and is routinely measured using height and weight to calculate a BMI. That classification depends on the BMI and it appears to relate to increased occurrences of various non-communicable diseases. They also provide the caution in relying on this and other common definitions of obesity that these measures can be quite problematic because they're statistics, right? We can't just take a number, apply it to

a chart, and determine health. They require interpretation. Personally, I don't use the language of obesity in my own work to define my body as a fat woman. It's a very biomedical term. It really is focused on how you are in relation to a standard. I also tend to avoid terms that talk around fat like large body, plus size. I tend to just actively use the word fat. And so your listeners will hear me call myself or talk about other fat women.

It's not meant to be a negative. It's an adjective. It talks about and refers to a size and it's inherently neutral. But as a society, we've come to label fat as failure, as something you don't want to aim for or embrace or accept about your body. And so it's that application that makes fat a negative word. And in my work, we work to actively reclaim that word. So you will hear me use FAT quite a bit. And it's not meant to be a negative. It's actually just a descriptor of a large body. Thank you for saying that.

And I think it is important to look at those nuances of language and the implications there. So that is important. So over the years, the BMI measurement has become rather controversial. Let's talk about that. What are some of the criticisms that have been leveled at it? Yeah, absolutely. Many critical obesity scholars and fat study scholars talk about how BMI, it doesn't correlate directly with, say, levels of

fat on people's body. Scholars have found that it accounts for about 60 to 75 percent of body fat variation in adults, but also is completely inaccurate for measuring body composition in children. And yet, I'm sure many of us, myself included especially, despite this, have been exposed to the BMI scale since we were quite young. It also really fails to account for ethnic diversity or variation in how bodies are composed. So if you remember just a few minutes ago I mentioned how it was developed about Western European bodies, this ideal of a Western European man. Well, that's not a very diverse population. And scholars like Joy Cox and Sabrina Strings who do a

lot of work on race and fatness. Talk about BMI as an inherently racist tool to measure health because it only reflects what was assumed about those specific very white bodies, very male bodies. And women's bodies change over their lifespan too. So you have a child, your size, your shape, how your body holds fat is all going to change post-natally then pre-natally. So even that is not accounted for because men's bodies don't change in that same way. is all going to change postnatally than prenatally, right? So even that is not accounted for because men's bodies don't change in that same way. Another concern using BMI as an indicator of health

is that it doesn't really tell you more than a number, right? You get a number based on your height and weight, but it doesn't tell you what you eat in the day or how much you move or what stresses you're experiencing in your life. And we've seen this come up quite a bit recently in social media following the Olympics and with athletes like Alona Mar, who's a very muscular rugby player, female rugby player, whose BMI would absolutely put her in the overweight to obese category despite the way

her body actually physically exists and moves. And this isn't just unique to Alona. Many athletes would be considered overweight or obese based on the measure of BMI. Regardless of their health or fitness level, their muscle, it pushes them into those quote unhealthy ranges of the BMI whether overweight or obese. So Kelsey, it really sounds like what you're saying here is that BMI puts an emphasis on weight as an indicator of health, which then doesn't really give us a very accurate picture of health.

Is that fair to say? It really doesn't give us an accurate picture of health, especially if, as you know, doctors are often encouraging us to think about health as our lifestyle, as what we do, as who we are. It really only gives us a number. And there's been a lot of really interesting research both out of the US and Canada that have found that those concerns we're having about that overweight range to obese range of the BMI aren't actually as grounded in

the data as you know we're often led to believe in the media or in understandings of fears of becoming fat. There's some interesting research out of the CDC in 2005 and 2013. It found in both studies by the same authors and epidemiologists that the category of being overweight, so those are folks who have a BMI between 25 and 30, doesn't actually have high rates of mortality. In fact, it had significantly lower rates of mortality than those in the normal BMI range, suggesting that being overweight doesn't have that same all-cause mortality concern that we see represented. Even in those studies they found that being obese, and they stratify this a bit more, so they talk about grade 1 obesity, which is 30, a BMI of 30 to 35,

really doesn't have much difference in concerns around all-cause mortality as being in the normal BMI range as well. Just to clarify, this was like what we would call in in social science work a meta-analysis, meaning it reviewed study after study after study after study about the topic. So it was looking at already existing research on weight and health, and they found that negative health consequences in relation to mortality don't actually occur for at least 10 points higher on the BMI scale than what's used as that sort of categorization of normal body weight, a BMI of 25, and they're not really seeing those consequences until around 35, and they slowly increase from there. So I guess I wonder, with all of these issues that we've just discussed about BMI,

why has it continued to be used in such kind of a prevalent way? That's a really good question that I don't know that there's one clear answer to, unfortunately, because most doctors, if you ask them, will recognize, oh yeah, BMI is a problematic measure, and yet still use it in clinic, and yet still use it to determine health measures in practice. And you know, if I had to guess, I think it's because it's still very prevalent in public consciousness. It's a very easy measurement to determine. Doctors can easily point to it to sort of visualize for you, okay, this is a concern.

Look at how these numbers are changing. I think that as long as obesity continues to be represented as this giant social problem in need of treatment and intervention, whereas what you commonly hear of as the obesity epidemic, we're going to continue to see the use of BMI or other attempts at objective measurement tools to try and combat, diagnose, and intervene as a health measure. And now of course we have this other measurement that could replace BMI that people are talking more about.

This is called the Body Roundness Index. So this is the BRI. What is this based on, Kelsey? So the BRI, or the Body Roundness Index, was introduced around 2013, interestingly, Manika, by another mathematician, Diana Thomas. And this measurement tool uses waist circumference and height.

My understanding is that the rounder your body is, is based on a score provided by the body roundness index, the greater your risk is of all-cause mortality. But the major difference here with the BRI versus the BMI seems to be that by using measurements other than weight, less emphasis is being placed on weight as an indicator of health. Personally, though, I'm really skeptical that the introduction of another supposed objective measurement system will solve the concerns that are being flagged around the use of BMI and the stigmatization that comes from flagging bodies as obese by a body classification system and

using that to determine health. The BRI still constructs the fat body as a problem in need of a solution and it's still just a number with no indication like I mentioned earlier with the BMI of the lifestyle of the person that that number is being ascribed to. The one difference I think that people are pointing to though with the BRI is that, of course, it uses measurement at the waist, which you referenced before,

which is supposed to be a measurement of the fat surrounding the stomach and the liver. And this is supposed to be more of an indication of risk for kidney disease, diabetes, and cancer. So I guess that's the focus on that specific part of the body though. Isn't that supposed to be more accurate than in determining potential health risks as opposed to the BMI?

So that's what's being alleged, yes. But health risks, I would just caution, they come for people in all sizes, right? Just because you score well, score well for lack of a better term, on the BRI or the BMI doesn't mean you aren't at risk for potential adverse health outcomes. Doesn't mean you might not have a history of poor health outcomes related to kidney disease or diabetes, for example. We know there are genetic components to diabetes, but if you score well on the BRI, does that then get dismissed? I have the same concerns here around how the assumption that BRI can predict health risks would influence the interactions that healthcare providers have with their fat patients. It sounds like from your perspective, Kelsey, the BRI actually maybe doesn't address the main concerns that you have with the BMI.

Is that right? It still represents the fat or the round, in this case body, as a negative body, a bad one, re-entrenching all the stigma that comes along with that representation and really doesn't work to eliminate anti-fat bias in healthcare spaces. We'll be back in a minute. Kelsey, let's focus a little bit more on the healthcare experience then, because this is an important part of the conversation. And I know that in your work, you've spoken to dozens of Canadian women who identify as

plus-sized or fat about their experiences navigating the healthcare system. So I guess how do these general measurements that we've been talking about, like the BMI and the BRI, how do those factor into their experiences? So, we have a lot of quantitative work in medicine, in psychology, and sociology that tell us that the attitudes of healthcare professionals towards fat patients or overweight and obese patients impacts the care they might ultimately receive. Through my research, so I talked to a lot of different women and they shared their experiences of receiving weight loss advice from their doctors ranging from extreme dieting to starvation and even to surgical intervention. Often this weight loss advice was unsolicited

and unwanted. What's interesting is that this advice is often moralistic in nature, meaning their doctors would try and guilt them into weight loss or would represent their weight loss or lack of weight loss as something they were doing wrong. And in many instances when they could or would not lose weight, their healthcare concerns unrelated to their weight were not taken seriously by their doctors. Kelsie, I know you've spoken to many people. I guess are there any specific examples that come to mind that I guess illustrate these points that you're talking about? Yeah, so every woman I spoke to for my research shared experiences of fat phobia and anti-fat bias in health care spaces, often

starting in their childhood. So for example, one woman spoke to me about how her doctor encouraged her mother to put bells on their pantry, on their drawers, on their fridge, and any other space that food was so that everyone in the house would know if she tried to access food outside of designated meal times as a source of shame. Another example was a woman I spoke to who shared with me how when she wasn't successful or wasn't meeting her doctor's targeted weight loss for her, he asked her if she'd ever heard of the starvation diet and told her about how it worked really well for his

own wife to lose weight, encouraging her to starve herself and not eat as a way of losing weight, which both is unsustainable and incredibly unhealthy. So what is the impact of those kind of experiences in the healthcare system? The woman I talked to, they share these experiences of weight stigma resulting in a negative or non-existent relationship with their doctors, which ultimately led to either the denial of care by the doctor or avoidance of care by the patient. And avoiding care or denying care can have devastating or life-threatening consequences. If you don't go to your primary care doctor for primary interventions, like one I was really

interested in was mammograms and pap smears as women, how do you then get secondary care if something is flagging as abnormal, right? You're not going to receive that secondary care either. And what was even more of a concern to me is what if your doctor isn't putting the care into those exams that might be needed as well? And that was a concern that came up over and over from my participants was that doctors weren't giving them the time or referring them to, say, x-ray or CT or blood work, just prescribing, we would say, weight loss, telling them to come back when they've lost weight

and assuming health care problems would resolve themselves from weight loss. Yeah, so it sounds like the impact of those experiences, then, is that other aspects of their health, they're actually not getting those issues addressed in the way that they should be. Yeah, or they're not going back to the doctor the next time that they have an issue. One other participant I spoke to, she wasn't talking about her family doctor, but she was

talking about her psychiatrist. And her psychiatrist was talking about, you know, an antidepressant that she should go on. And it took my participant or this woman a couple of minutes to figure it out. But then the doctor ultimately said, I don't want to put you on that drug, the best drug for them, because it'll make you gain more weight. And this was not even a concern that the participant had brought up to the psychiatrist.

You know, I'm worried about starting a medication that might make me gain weight, but the psychiatrist was already navigating the decision based on whether or not a side effect was potential weight gain without consulting her if that was a concern she had. So Kelsey, when it comes to the experiences of plus sized and fat people in the Canadian health care system, I guess what would help improve the care that they receive? So from the people you've talked to, what would they say would be better? Yeah, so I frequently asked the women I spoke to about what changes could help improve their experience

in the healthcare system. And the number one answer that I got was, they wanted to be treated with respect and with autonomy and agency, and they want their doctors to recognize their humanity. They want to be seen as more than just a fat body in a doctor's office who is probably there for weight loss advice, because often they're not. Being in a doctor's office will not be the first time they have

been told they are quote obese or recognized as such, in fact it's probably not even the first time in that particular office. They want to be trusted when they discuss their health and concerns, and for doctors to recognize that just because they are fat doesn't mean they are necessarily unhealthy, or that fatness is the cause of the reason of ill health that they may be experiencing. You might not be healthy, but if you're coming in with pneumonia, right, perhaps your fat body is not the reason for the pneumonia, and prescribing weight loss might not be the solution. Many of the women I spoke to express how their doctors automatically assume they have unhealthy diets or that they don't engage in exercise. So they want to be asked, they don't want you to assume what their lifestyle is

or that they are quote unhealthy. People also just want to be respected. They want to be heard. They want to be seen as a whole person and not as someone quote living with obesity. They want to be asked what else is going on in their lives that might be contributing to their health. You know, healthcare providers recognize that there are these things called social determinants of health, which means more than just our biology and our physiology can contribute to our health. So example living in poverty, having insecure food access, your race, all of these different factors that we call social determinants of health also exist for fat people as well. They don't want to be offered unsolicited weight

loss advice over and over and over again. They just want to be heard and listened to about their health concerns. Just before I let you go here, Kelsey, just kind of coming off of that, are there any positive experiences that come to mind? So anything doctors have done that have made you or people that you've spoken to, I guess, feel more welcome in those healthcare spaces? So despite having many negative experiences with healthcare, and my own negative experiences are what sort of motivated me into this field, I currently have a healthcare team

that, personally, I'd describe as amazing. With my primary care doctor, one of the most important aspects of my care, for me, is that she listens to me, that she hears me, but that she still engages me in difficult topics and discussions. And what I mean by that is that my weight isn't off limits in a discussion. It's still a part of me. But my health and my weight are not the same thing.

And I think that this is what's important for all healthcare providers to keep at the forefront when they work with their fat patients. So for example, earlier last year, I went to my doctor and my blood pressure was quite high. It was abnormal for me, which meant my doctor wanted to have a discussion about what was going on. Now this discussion of course included my weight because I'm a large person that impacts your blood pressure, but it didn't just include my weight. We also talked about what was going on in my life. What does my work-life balance look like? And am I improving that work-life balance at all?

How things are going with my child? What exercise and movement I'm doing? She viewed these issues holistically and treated me as a whole person instead of only focusing on my weight. And funny enough, in this discussion, she said to me, you know, Kelsey, how do you feel about medical weight loss interventions like Ozempic? And before I could even say that I wasn't interested, she stopped and went like, actually, that doesn't solve the problem I have with you, Kelsey, is that you

go, go, go all the time. And you're not eating until like eight o'clock at night after you put your kid to bed. So Ozempic as anizer person, isn't going to work here. Let's talk about what else is going on in your life. So it wasn't that it wasn't a conversation we could have. It was one where she recognized the realities of my life. What else was going on to cause my high blood pressure. Did express to me that she was concerned about the impact my weight would have on my blood pressure, but did not just reduce me down to that weight and make that the only component of my life we're talking about. If you wanted to talk about a weight-related concern, ask if they want to talk about it, hear the yes or the no, and then respect that decision. Kelsey, really appreciated talking to you today. Thank you so much for being here.

Thank you so much for being here. Thank you so much for having me. That's it for today. I'm Maynika Ramon-Wilms. Our producers are Madeleine White, Michal Stein, and Allie Graham. David Crosby edits the show. Adrian Chung is our senior producer and Matt Frainer is our managing editor. You can subscribe to The Globe and Mail at globeandmail.com slash subscribe.

Thanks so much for listening, and I'll talk to you tomorrow.