Front Burner - Introducing The Dose with Dr. Brian Goldman

Episode Date: February 29, 2020

The Dose is a new weekly podcast that answers everyday health questions like: What vaccines do adults need? Does your Fitbit actually make you fitter? Or, should I bother taking vitamins? Dr. Brian Goldman and the team behind White Coat Black Art bring you the best science from top experts in about the same amount of time as an appointment with your GP. Subscribe to The Dose at smarturl.it/thedosecbc

In the Dragon's Den, a simple pitch can lead to a life-changing connection. Watch new episodes of Dragon's Den free on CBC Gem. Brought to you in part by National Angel Capital Organization, empowering Canada's entrepreneurs through angel investment and industry connections. This is a CBC Podcast. Hey everybody, so we have a very special bonus episode for you this week. It is called The Dose with Brian Goldman. It's a new health podcast from the team behind CBC Radio's White Coat Black Art. And so each week, Dr. Goldman is going to bring you the best science from the top experts in plain language, stuff that you can actually understand. And he's going to be exploring questions like, what vaccines do adults need?

Does your Fitbit actually make you fitter? Or should I be taking my vitamins? The dose is really going to help you cut through all of the confusion in health news. In episode one, Dr. Goldman dives into the pros and cons of body mass index to find out whether you should really worry if your BMI is too high. Have a listen.

Hi, I'm Dr. Brian Goldman. This is The Dose, a weekly CBC Health podcast that cuts through jargon and confusion to give you smart health information you can use. This week, the BMI and whether you need to stop worrying about it. The BMI or body mass index has been around for around 200 years. You know those charts where you plug in your height and weight and it spits out a number that tells you what your BMI is. Having a high BMI is supposed to be a call to get serious about your health by losing weight. But here's the thing. Recent studies say BMI is both inaccurate and misleading.

So, should you care about your BMI? To cut through the BS about BMI, I've dialed up Dr. Arya Sharma, who is a professor of medicine at the University of Alberta and who just happens to be Canada's obesity guru. Hi, Arya. Hi. So, for people who might not know what BMI is or maybe just aren't sure how it's calculated, can you give us a simple rundown? Sure. Body mass index has been around for a long time, and we might get into the history of BMI. But what it basically is, it's a number that's calculated based on height and weight.

So you measure your height, you measure your weight, and then there's a simple formula. So you measure your height, you measure your weight, and then there's a simple formula. You plug the numbers in and you end up with this number, which for an adult can be anywhere between 15 and over 100. And what body mass index actually is, it's a number that's often used to diagnose obesity. And it's a number that's been used for a long time for exactly that purpose, but it's not a very good number to be using for that purpose. And I guess that's what we're going to be talking about. In just a moment. So give us a sense of what the numbers are supposed to mean if you have a BMI of, say, 30 or 35, for example.

The conventional cutoff that if you open any medicine textbook or you check up, you know, look at any of those charts, what you'll normally find is that anything below 25 is considered normal weight. And once you get past a BMI number of 25 to 30, it's considered overweight. And then you go from 30 to 35. And now we start calling it obesity. And you have class one obesity. And then 35 to 40 is class two obesity. And anything over 40 is class three obesity. Have you ever figured out your own BMI? Well, my own is, yeah, it's hovering around 25. So that's good. So it's on the edge if you want. It's supposed to be good.

Well, we'll get into that. Where did this measurement come from? Well, the BMI number used to be called the catalytic index. And it was actually, it's almost 200 years old and was figured out by a mathematician who liked, you know, putting numbers to things. And he actually developed the number or looked at the number when he was describing the sizes of people, I believe it was in the Belgian troops at the time. And that's where the number came from. And it kind of found its way into the medical literature probably more

in the early 70s, where there was a guy called Ansel Keys, and he then actually called it the body mass index and started using it in a lot of studies that he was doing on body composition. And actually, he's best known perhaps for what we call the Minnesota starvation experiments, where they took a bunch of conscientious deniers who didn't want to go out to Vietnam, and they said, well, then you volunteer for a good cause. And they put them in these camps and they starved them as a way of studying what would happen to soldiers who were being held in concentration camps and prisoner camps and would be starving to death.

And so they took these guys and they put them on these basically starvation diets. They starved them. These were, quote, unquote, volunteers and very carefully measured their metabolism and their body composition and how they lost fat mass, et cetera. And so in the context of those studies, somehow the body mass index was used and that's how it found its way into the medical literature and then became this measure of body composition. What's the biggest myth that's out there about BMI? Well, I think the biggest myth in general is that you can step on a scale and decide whether you're healthy or not.

The biggest problem out there is the so-called healthy weight because the term healthy weight implies that there's a weight that you have to be at to be healthy when we all know that there's actually a wide range of weights that people can be at to be healthy when we all know that there's actually a wide range of weights that people can be at to be healthy. You know, in the same way that not everybody who's big, you know, is sick or has a health problem, not everybody who's skinny is healthy. So this idea that there's a healthy weight or there's a BMI number or there's a certain amount of, you know, pounds or kilos that your scale needs to show, which defines whether or not you're healthy or not, I think that's the biggest misunderstanding in all of this.

If I'm doing a population study, say I'm Statistics Canada and I want to know, is there going to be more obesity across Canada? Well, then BMI is okay for that because we're looking at populations. Where the problem is is not everybody who falls into that higher BMI category actually has a health issue and not everybody who is below that category is healthy. But chances are that the higher the BMI, the more health problems you have and chances are the lower the BMI, the fewer health problems you have. But when you take this down to the individual level, when you say – when I look at the guy sitting in my office and all I know about him is his BMI or his body weight, that's not enough information to base any kind

of decision on. So it works nicely for population studies. It does not work in medical practice when I'm trying to come up with a treatment plan for someone or even trying to figure out if somebody actually needs a treatment at all. So if it's not useful when it's applied to an individual, why are we still using it? Well, I think it's logic because it's simple. It's a number. We like numbers and we like things that are simple. And I think a lot of the thinking in medicine has often been, for many conditions, has been around numbers. If you think about what's a normal blood pressure, well, there's a number. What's a normal cholesterol level?

There's a number. What's a healthy blood sugar level? There's a number. So for a lot of, you know, things that we do in medicine, we have certain numbers, and those numbers, they define the cutoff. and those numbers did define the cutoff. But the problem is that obesity doesn't work that way because one of the things we've learned about obesity is not just that it's not about the amount of body fat that you have, but it's really about the kind of body fat that you have.

And when I say the kind of body fat, we're talking about quality of the fat but also location of the fat. And that has a huge impact on whether or not that body fat is affecting your health. The body fat that's not so good and the one that seems to cause a lot of problems is the body fat that's inside your body. So it's not body fat that you can pinch using your fingers. So this is the fat that's inside your abdomen. It's around your internal organs. So that in itself actually explains why you can see some people, they have a lot of body fat, but all of this body fat is located on their thighs, it's on their hips,

and doesn't seem to cause a lot of health problems. Now, they might not like it, they might not like the appearance. But in fact, there's actually even data showing that if you have large thighs and large hips, your risk for diabetes might actually be lower and not higher in contrast to someone who has all their excess body fat inside their abdomen or around their belly. In the Dragon's Den, a simple pitch can lead to a life-changing connection. Watch new episodes of Dragon's Den free on CBC Gem, brought to you in part by National Angel Capital Organization, empowering Canada's entrepreneurs through angel investment and industry connections. Is BMI affected in any way by ethnicity or genetic background?

Well, we know that ethnic background and ethnicity and ultimately genetics plays a huge role in whether people develop certain health problems when they gain weight or not. And so it absolutely does play a role. And what we do know about ethnicity and weight gain is that people from South Asia, for example, are much more sensitive to changes in body weight. So let's take somebody who comes from East India. If that person simply by gaining two or three pounds can make all the difference between not having diabetes and having diabetes. So they're very, very sensitive changes in body fat. And there's other people of other ethnicities who are much more resistant.

So they can gain quite a considerable amount of weight and not have health problems. So, yes, ethnicity plays a role. Genetics plays a role. And that's exactly what makes this so complicated. I like to think of body mass index as a clothing size. So when you tell me, you know, there's someone with a body mass index of 45, I know that that's a pretty big guy. But it doesn't really tell me much about health. I mean, let's talk about a sumo wrestler.

You know, those are high-performance athletes, and they'll all clock in at BMIs of, you know, 45 and 50. So, you know, you'll say, whoa, that's severe obesity. But I wouldn't call it severe obesity because, like I said, they're athletes. So just having that number doesn't really tell me much about health. Yet we still see those charts in offices and you can go online and plug in your height and weight to get the number. Yeah, but I wouldn't make too much of that number. I would look at those numbers more as a screening tool. So yes, as people's body mass index goes up, the likelihood or the chances that they might end up with a health problem related to their body fat or their

body weight goes up. And the heavier you get and the larger you get, the greater the risk. And when you talk about health, you're talking about trying to connect some number to what? Fatty liver? To elevated triglycerides? Is that what you're talking about? Type 2 diabetes? Exactly. Whatever the problems are.

So as I said earlier, there's about 200 conditions, well-defined conditions or medical diagnosis which you want. And fatty liver is one of them. Sleep apnea is another. Type 2 diabetes. High blood pressure. We've got osteoarthritis. We've got a whole one of them. Sleep apnea is another. Type 2 diabetes. High blood pressure. We've got osteoarthritis. We've got a whole bunch of conditions. There's a lot of cancers that may be caused by and may be driven by excess body weight if you want.

But not everybody has all these problems. And so what a lot of people don't like about throwing out the body mass index is that now when you say obesity is something where we need more information, well, now we're really talking about a visit to your doctor's office and we're talking about running some lab tests and we're talking about, you know, doing a physical exam and we're talking about a whole bunch of other things. And suddenly this thing becomes complicated, but it is complicated. I mean, it's no different from a lot of other medical problems where you have to actually go to see a doctor to find out if you have the problem. Do you think some people might avoid that visit to their doctor because they're ashamed of how high their BMI is?

Well, absolutely. You know, very few doctors have actual training in obesity. And even today, I always say, you know, if you want a mic drop moment, you know, we're still graduating people from medical school who have never spent even 30 minutes treating someone for their obesity. We had the CMA come out and say obesity is a chronic disease six years ago. You ask them, well, what have you done about it? Nothing. We've not trained one extra doctor since then. So your chances of seeing an obesity specialist in your lifetime is virtually zero if you live in Canada or anywhere else. Mic drop.

There you go. Canada or anywhere else. Mic drop. There you go. Okay. All right. So is there a better number than a BMI that we should be using instead? Well, unfortunately, there's not a number. You know, and that's what people don't like about this discussion. You know, they want numbers, but there is no number. Some people, some experts I've spoken to have been talking about measuring your waist

circumference. Well, again, you're talking in numbers. So, you know, there's people who have large waist who have, you know, who have health issues and there's people who have large waist who don't have health issues. It doesn't add a lot to the clinical test. So again, you know, if you measure your waist circumference and you're above one of those cutoffs on a chart, then again, maybe you want to bring this up at your next doctor's visit. But it doesn't – it's not diagnostic and that's the key issue here. In medicine, we want something that differentiates people who have a health problem or people who are sick if you want from people who are healthy. if you want, from people who are healthy.

And unfortunately, body weight, BMI, waist circumference, there's simply not enough information in those numbers for me to, as a doctor, make a diagnosis or decide what the best plan of action is. Obesity is not a diagnosis that you can make by looking at someone on the street or by even having them step on a scale. Obesity is a diagnosis that should be made in a doctor's office after having run the appropriate tests. And what's the tripwire to talking to your doctor about doing something about being overweight or obese if you're worried about all those diseases like heart disease and

type 2 diabetes? Well, a lot of these diseases start very early, you know, with early signs. And so your first step is to see if you have any of those early signs. And sometimes it's not just the early signs. Sometimes it's just having a strong family history. So if there's a lot of type 2 diabetes in your family, you know, that you're gaining weight or that your weight is up, then once again, we're back to the doctor's office. Run the test and see if you have prediabetes. And if you do, then you need to start thinking about what it is that you want to do about the body weight. Ultimately, it comes down to the question, is your body weight

or is your body fat affecting your health? That's the question you're really asking. And if it is, then you need to do something about it. And if your doctor runs all the tests and they look and see your cholesterol is fine, your triglycerides are fine, you don't have sleep apnea, your blood pressure is fine, your kidney function is fine, your liver seems to be fine, well, then hopefully your doctor is going to tell you that this is not something you need to worry about. On the other hand, this might prompt your doctor to run a few tests and they might find something that actually is wrong and that needs treatment. So I look at it as a screening tool, maybe as a conversation starter, but not as a diagnostic tool.

So what's the bottom line on BMI? The bottom line on BMI is don't obsess about it. Use it as a screening tool. So if you're interested and you check your own body mass index on one of those calculators or look at a body chart, then I would advise to bring this topic up the next time you see your doctor. But don't lose sleep over it because chances are that it doesn't mean much. Dr. Sharma, I want to thank you for joining us today on our very first episode of The Dose. I got to run.

Take care. Bye. Yeah, bye. Arya Sharma is a professor of medicine at the University of Alberta. You can find out more about the work he does at obesitycanada.ca. So what's the dose of advice on your BMI? At best, it's a signal that might tell you to lose some weight. But the BMI tells you nothing about your health. Your blood pressure, triglycerides, blood sugar, liver tests, and family history will tell you far more about your health. Your blood pressure, triglycerides, blood sugar, liver tests, and family history

will tell you far more about your health. If you want to talk about BMI and any other questions you'd like us to tackle on The Dose, tweet me at NightshiftMD or at CBC Podcasts or at CBC White Coat using the hashtag TheDoseCBC. You can also email us. Our address is TheDose at CBC.ca. You can find The Dose whereverBC. You can also email us. Our address is thedoseatcbc.ca. You can find The Dose wherever you get your podcasts.

The Dose was produced by Nicole Ireland, Donna Dingwall, and me with digital support from Olivia Pasquarelli and Fabiola Carletti. This week we had help from Austin Pomeroy. Shout out to Alison Broadle, Managing Editor at CBC Radio, Arif Noorani, the Executive Producer of CBC Podcasts, and Leslie Merklinger, CBC's Director of Audio Innovation. And one more thing.

The dose wants you to be better informed about your health, but if you're looking for medical advice, see your health care provider. I'm Dr. Brian Goldman. Until your next dose. If you liked what you heard, you can listen wherever you get FrontBurner. Just search The Dose.