Short Wave - Should race affect BMI guidelines? Doctors are split

Episode Date: September 14, 2026

BMI is a quick, cheap way for doctors to estimate body fat and screen for conditions like heart disease and diabetes. But medicine has long known that BMI is problematic and unnuanced. By using it, groups of people have fallen through the cracks and conditions have been caught late. So, some doctors want to add nuance – to consider race when using BMI. But using race in medicine comes with its own problems. So what’s the way forward? To find out, we talk to Katie Wu, a science writer at The Atlantic.Read more of Katie’s reporting on BMI and race.Interested in more science health stories? Email us your question at [e-mail] public media with NPR+ and enjoy perks for over 25 podcasts like this one. This show’s perks include sponsor-free listening. Learn more at plus.npr.org. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. You're walking into your doctor's office for your annual checkup. You probably fill out a form or two. Then your doctor starts going down a checklist. Taking your temperature, blood pressure, height, and weight. These last two are used to figure out your body mass index or BMI, the bane of many people's existence. That's used to determine your risk for a whole bunch of dangerous common health conditions like heart disease. and type 2 diabetes.

And okay, that's probably not news to you. But you know what was news to me? BMI was never intended for medical use. This is a roughly 200-year-old metric that was invented by, honestly, some random scientist dude who was European. And his goal was not to invent, like, oh, this is going to be the ultimate medical measure to define overweight or obesity or give people a, a, diagnostic or screening tool.

Now, he truly just wanted to look at the people around him and determine the characteristics of the ideal form. And because it was, you know, the 1830s, it was like the ideal white male form. That's Katie Wu. She's a staff writer at the Atlantic who looked into BMI. And why, despite this origin story, researchers still found it useful. And over time, it became a blunt way of lumping people into four groups, obese, overweight, healthy weight, and underweight.

And that is still essentially the categorization system we have in place today. You can go on the CDC's website, the World Health Organization's website. The cutoffs are pretty similar, and for the most part, it's quite universal. And that's the issue a lot of regular people and doctors today have with BMI, because people are really varied. I think any time you try and apply some sort of universal categorization metric to an entire species with Billy. and billions of people from all around the globe where there are different sexes, different genders, different cultures, different heritages, different people with different muscle mass, different lifestyles. It's not going to work. It's complicated. There are people with, you know,

quote-unquote, high or overweight or obese BMIs who are extremely healthy. Many athletes are a classic example. And conversely, plenty of people in the technically healthy weight category who are experiencing all sorts of metabolic issues. And that has issues. Research suggests that certain racial groups have been underscreened for type 2 diabetes. So why haven't doctors just scrapped it for something better? It is simple and easy. I mean, it is something that factors in height and weight. These are in everyone's chart. A lot of doctors can't imagine their practice without it. But so much goes on beneath the surface and BMI doesn't account for most of it. And in an attempt to change that, experts have started considering another factor when deciding BMI cutoffs, race.

So today on the show, what led to race-specific BMI cutoffs, the pushback against it, and whether we should be using BMI in medicine at all? I'm Regina Barber, and you're listening to Shortwave, the science podcast from NPR. Okay, Katie, from reading your article, it's clear that there's a lot of issues from using BMI. So why are so many doctors and researchers recommending considering race when deciding BMI cutoffs for conditions like type 2 diabetes where the body doesn't regulate insulin well? Yeah, I think this issue is just one really clear symptom that we're having trouble letting BMI go. This has been kind of a movement that's been really more than a decade in the making. And it started at a time when BMI wasn't being as heavily questioned as it is now.

you know, even a decade ago, BMI was diagnostic. Oh, yeah. You get a number. And that's just who you are. And, you know, there's a whole host of other issues with over-fixiting on those terms and people feeling body-shamed. And researchers were noticing that a lot of Asian-Americans were developing conditions like type 2 diabetes at BMI's that were way below the threshold typically considered for obese and

overweight, like BMI's of 23, 22, you know, around the range that you would normally consider. that are healthy weight and not worry so much unless there are other, you know, big, major red flags in your chart, you're probably fine, right? The answer was just so often no, yeah, that a lot of researchers were saying, okay, we've got to do something about this. They're developing complications, and their health is really suffering. Wow. So is that what sparked this change? Like, seeing people in the Asian community just, like, not being diagnosed early in them. Definitely. I think, you know, in a lot of practices, people were using the BMI cutoff of, you know, roughly what's considered overweight, 25 or higher, as, okay, here's one clear risk factor for diabetes,

but so many Asian Americans were falling below that threshold that they basically weren't getting scored as highly as they could be for diabetes risk. And that was leaving them to fall through the cracks. A lot of the researchers I talked to were even talking about how they had family members who fell into that category. And, you know, their cases were almost caught too late. They were thinking, this is my community. I have to be able to do something. So let's lower the cutoff. There was this whole movement that became described as screen at 23, targeted toward Asian Americans and Pacific Islanders. And, you know, it is still a general recommendation today. Wow. Okay. And that's because you wrote in your article that certain subsections of the Asian

community are more likely to carry fat around our midsection. Like, why is that important? Yeah. There are definitely subgroups. of people who fall into the giant bucket that is Asian Americans that do seem to have like a biological underpinning for what's going on. So there are different types of fat in our body. And the fat we worry about most for, you know, metabolic conditions like diabetes is called visceral fat. This is the fat that accumulates more centrally in our body. It's not going to be the fat that you can kind of pinch on your arm. It's going to accumulate around your organs. It can cause inflammation. It can, you know, start to drive things like insulin resistance where you

can't regulate your own blood sugar. And it seems like certain subgroups of Asian Americans tend to carry more of this fat. So they may weigh exactly the same as another person who is not Asian American, but have more of this dangerous fat in a way that won't be caught by something like just regular old BMI. Yeah, I mean, I'm of Asian descent. You are of Asian descent. It's a huge category, right? So including race in medicine has been a point of controversy. So how effective has it been to include race in BMI cutoffs? This has been hard to track, honestly, in part because Asian Americans weren't well represented in a lot of national health surveys until 2011. There hasn't been like a systematic analysis of like how big of a tangible impact

has screened at 23 had. Certainly the researchers and doctors I'm talking to say that they talk to a lot of their patients about this. They have been actively increasing awareness themselves. And it seems like there's some data that suggests that cases of undiagnosed diabetes have gone down in this population over time, which is really encouraging. But honestly, a lot of them are advocating for more awareness, which puts them in a tricky situation. Because exactly, as you said, we're also at this moment where doctors across fields of medicine are trying to de-emphasize race as a factor. Right, that it's not biological. Exactly. Yeah, race is the social construct that is kind of this poor proxy for

socioeconomic status, culture, lifestyle, environment, all of these other things that can correlate what someone's stated race or ethnicity, but it's not a perfect predictor. And we don't want to overinflate, you know, the role of genetics in what's going on here. It's really tricky because having a kind of race-sensitive BMI scale both does address some of the universal BMI scale shortcomings, but it at the same time highlights some of the issues with relying on race to any capacity, right? Yeah, it opens another can of worms, right? Like, I myself am half Chinese and half Mexican, so I'm not, I don't even fit into those bins, right? Exactly. And in a lot of clinical settings, like when you go to the doctor, they're not looking at you and saying, oh, Gina, like,

I'm going to put you in this category. You self-identify. You sort of choose what sort of risk factors to talk about with regard to race in the city. Yeah. Another big complication is researchers don't have enough information to really carefully stratify, oh, maybe there's a, um, maybe there's a, higher risk among South Asian people should be stratified there. Right now it's just kind of, if you're Asian American, let's lower your BMI cut off, I guess. Yeah. And that's still a really huge group of people. Yeah. We can't continue to rely on a system that has, I wouldn't say, 100% failed us, but it's

really not as good as we can do. We need something that can take into account. Actual fat mass, actual muscle mass, you know, things that actually tell us about body composition and the types of cells in our body that are actually putting us at higher or lower risk of specific diseases. Then are there alternative measurements that could be used instead? Right. And this is where it gets tricky. We can't give everyone a full body scan. You know, certainly our healthcare system is not set up to offer that technology to everyone. Just an unfortunate work of living in this country. So what do we use instead? It has to be something easy to measure. It has to be something relatively cheap. And it has to be something that is not going to be really prone to user error. Like depending on who is doing the measurement, you're not going to introduce all sorts of noise into the data. That's a really, really, really hard set of criteria to meet. And so some people talk about, like, we could measure people's waist circumference, compare it to their hip circumference maybe, compare it to their height. But oh my gosh, where do you measure waist circumference? Is it at the very top, the exact middle? What about people with different

body shape? What if I had a really big lunch day? What if I breathed in really sharply right when you took out the tape measure? Yeah. It's a mess. And just to put the cherry on top, There's data suggestion that just like with BMI, it may help to include some race sensitivity to that. And so there's kind of no escaping this degree to which we do need to personalize for everyone, but also what's the ceiling on how much we can personalize without, you know, adding hours to the schedules of clinicians who are already so overstretched, especially in primary care. Yeah. So are there any other options doctors are looking at? So another option that people are considering, especially in the diabetes world, is

why don't we just screen everyone? Let's stop relying on these messy screening techniques, maybe everyone above a certain age. Oh, so you mean like what we do for colonoscopies? Yeah, sure, right. Like, let's stop saying you need to be tested further and you don't need to be tested further. Let's just test more people. And so there are a bunch of ways we can look more directly at how people are regulating their blood sugar, including this blood sugar test called A1C. You know, there are ways to go about this that sort of skip the grading question, but not everyone agrees that this is going to be cost effective. And also, some of these tests also have their own issues, like, are the cutoffs low enough for different

racial and ethnic groups? Yeah, it seems like it's also difficult to have these conversations about race with patients, right? Totally. I spent so much of my time reporting this story, thinking about how easily so much of this could be misinterpreted. Like, you set these different cutoffs for Asian American populations, and you so easily open the door to, well, I'm not fat, but I'm Asian fat, and I feel horrible about that, or just reinforcing unfortunate body standards. And I would just love to get away from any system that makes it easy to make those errors. But at the same time, I'm not sure I see one. You know, medicine is so much about, like, we do need to do things quickly. But at the same time, it's so important to talk to your patients,

to listen to them. And that takes so much time that our health care system is not built for. Yeah. Where do you see all of this going? Like, now that we're Medicine is now looking at these issues. What can we do with that information? Yeah. I think all of this is pointing toward medicine evolving away from factoring in race and BMI, both separately and together, moving away from factoring in those things in the ways that we traditionally have. But I don't think this is going to happen overnight. I think there's kind of multiple reckoning happening here. One is reckoning with the fact that we can't rely on these things as much as we have, but also reckoning with the fact that it is really hard to change

things in medicine. And just because something has stuck around in medicine does not mean it's perfect and does not mean it can't be improved upon. Katie, thank you so much for bringing us the story on BMI. I learned so much. Of course, anytime. If you like this episode, please share it with a friend. You know, that friend that's like, BMI matters. And you're like, does it? Kind of. It's complicated. This episode was produced by Arundez. Nair and edited by our showrunner Rebecca Ramirez. Tyler Jones checked the facts. Robert Rodriguez was the audio engineer.

I'm Regina Barber. Thank you for listening to Shorewave from NPR.