The limitations of Body Mass Index (BMI) measurements are well documented in health and medical research and yet it remains the sole diagnostic tool for obesity.
The Lancet Commission on Clinical Obesity, composed of over 50 global health experts, launched groundbreaking guidelines to redefine obesity as a chronic, systemic illness by introducing a nuanced framework that diagnoses and treats obesity more accurately – ultimately shifting away from using BMI and ensuring equitable evidence based care.
For our December Speaking of Science webinar, we were lucky to hear from one of the global health experts, Professor Louise Baur AM of the University of Sydney to discuss is obesity a disease or a risk factor and the changing paradigms with new definitions.
Professor Baur AM shared her insights from being involved in the Lancet Commission on Clinical Obesity, and discussed how we can better improve early interventions, accurate diagnoses and healthcare systems to prioritise care for the most in need.
Listen to the thought-provoking discussion below.
Recorded on Thursday 4 December 2024 from 1:00PM – 2:00PM AEDT.
- Video transcript
00:40 Professor Steve Wesselingh
Okay, I think we might start. I can see that people are still joining us, but because of the time, I think we might start and by the time people have joined us, we'll have our speaker speaking, and then that's why you are here, not necessarily to listen to me.00:57 Professor Steve Wesselingh
Welcome everyone, and thank you for joining us today, for Speaking of Science, our webinar series where we delve into the stories of the nation's outstanding researchers and talk about their topics and how they came to work in that area, and what they've achieved.01:17 Professor Steve Wesselingh
Before we start, I'd like to acknowledge the traditional custodians of the land that we're meeting on the Ngunnawal people, and pay my respects to elders past, present and emerging and also acknowledge any Aboriginal and Torres Strait Islander people who may be present with us today. For a bit of housekeeping, I'd like to remind everyone that there'll be an opportunity at the end to ask questions, and so please put that in in the chat, and also remind people that we're recording. This will be available to look at later, and also that you can look at all of the other webinars that we've had in the past year, and also highlight that this is the last one for the year.02:03 Professor Steve Wesselingh
I think it's been a really exciting year when we had some fantastic webinars from really the best health and medical researchers across a range of topics in Australia, including mental health, brain cancer, Aboriginal and Torres Strait Islander social and emotional well being, consumer involvement, all sorts of things. But today, both the speaker and the topic are really inspiring and really important.02:32 Professor Steve Wesselingh
It's estimated that about a billion people currently live with obesity worldwide, and this probably will go up to about one and a half billion people by 2035 and this clearly is a major issue in the world today. As most of you know, we tend to use BMI or body mass index, to diagnose obesity, and that obviously uses height and weight. But there are lots of problems with the BMI, and it doesn't necessarily look at a person's overall health, and doesn't really help you tailor the treatments to that person. Recently, the Lancet Commission on clinical obesity, composed of over 50 global health experts, launched groundbreaking guidelines to redefine obesity as a chronic systemic illness published in The Lancet Diabetes and Endocrinology, the guidelines introduced a much more nuanced framework to diagnose and treat obesity, ensuring more accurate care and reducing the risk of over diagnosis by shifting away from using BMI. The guidelines highlight two stages of obesity, pre clinical obesity, where excess body fat that does not yet cause organ dysfunction or health issues but poses a future risk, and clinical obesity, where excess body fat has led to health complications such as high blood pressure, obesity linked heart failure, failure, sleep apnea, hip or knee joint pain, requiring immediate medical interventions.04:13 Professor Steve Wesselingh
These new guidelines aim to improve the accuracy of clinical obesity diagnosis and ensure that we don't unnecessarily treat people, but we also ensure equitable, evidence based care for the people who need it. They also highlight the urgency of addressing obesity's role in driving non communicable diseases such as heart disease, diabetes and certain cancers, by focusing on early intervention, accurate diagnosis and healthcare systems that can better allocate resources and prioritise care for those most in need, as actually the WHO recently mentioned in terms of the new obesity drugs and some of the equity issues around those obesity drugs that are availabile across the world today.05:05 Professor Steve Wesselingh
I think I've told you enough about obesity, but we're going to actually hear from one of the experts who was on the Lancet Commission on Clinical Obesity and who has done amazing work in the area, Professor Louise Baur. Louise is the Professor of Child and Adolescent Health and an NHMRC Leadership Fellow at the University of Sydney. She's a consultant paediatrician in the weight management services at the Children's Hospital at Westmead, a programme she established for the multidisciplinary care of children and young people with severe obesity. She's made research contributions in many aspects of treatment and prevention of child and adolescent obesity and paediatric nutrition and aspects of food policy. She's also the director of the NHMRC Centre of Research Excellence on the early prevention of obesity in childhood, which is now in its 10th year of operation, clearly being funded twice. She's also the current President of the Australian Academy of health and medical sciences and the immediate past president of the World Obesity Federation. In 2010 she was made a member of the Order of Australia. What an amazing CV, what an amazing Australian researcher for us to hear from, and I'm glad to say, an Australian researcher funded by NHMRC, so thank you, Louise, and really looking forward to your talk.06:37 Professor Steve Wesselingh
You're muted. Louise. Professor Louise Baur AM 06:48 Thank you, and thank you NHMRC for funding my research work. It's always very, very welcome.07:00 Professor Louise Baur AM
Hello, everybody and welcome to this session. As I start, I would like to acknowledge the traditional custodians of the lands on which I am. I'm meeting from Western Sydney, Westmead region. So that's the Dharug people. Aboriginal and Torres Strait Islander people were our nation's first scientists, innovators and healers and and had a rich tradition of caring.07:41 Professor Louise Baur AM
Can you hear me again? I just got muted. Okay, good.07:49 Professor Louise Baur AM
I welcome in the Aboriginal and Torres Strait Islander people here today. As I start, I'd like to just tell you about the disclosures. The Lancet Commission, which I'm going to talk about in some detail, received no funding by any of the commissioners, received no industry money or anything like that. The logistics support was provided by King's Health Partners, which was sort of equivalent to a Lancet to a local health district. My own personal disclosures are shown there, and I will be talking largely about this paper that was published early this year. It came out mid January, paper published in March, and has had multiple citations this year, and it's created a lot of broad interest. But let me tell you about how we came to do this work.08:52 Professor Louise Baur AM
We can all use the same words, but mean different things. The word body mass index can be used by an epidemiologist and is seen as an epidemiological tool and concept, and I'll show you a bit later on how that could occur. It can also be used as a clinical tool for screening and for clinical diagnosis and for other purposes. We can reflect a little bit later soon about some of the limitations there. But obesity itself can be seen as a risk factor, say, for heart disease or diabetes. I'm also going to be say that I see it as a clinical disease in its own right, and when is it. But for many people, it's a very stigmatising term. All of these can be correct in different circumstances, and this is part of the challenge of being able to talk about these issues.09:49 Professor Louise Baur AM
Now I want to help us spend a bit of time thinking about what is a disease. So many textbooks will have a definition of disease that you can see here on the left, a harmful deviation from the normal structural or functional state of an organism associated with certain signs and symptoms and limitations of daily activities. Think about many diseases, and you can see how that would fit in now the WHO definition of obesity, or until very, very recently, talked about an abnormal or excessive fat accumulation that presents a risk to health.10:29 Professor Louise Baur AM
The first concept here is that when we talk about a disease, we talk about a negative impact on health at present, whereas a risk to health, the risk may and may not materialise in the future, and this has been one of the challenges, I think, that we use when talking about obesity, about when it might be a disease. If we think about the anatomy of disease, and we think about the aetiology, there could be a number of causes, genetics, infectious, environmental or unknown, there's a specific range of pathophysiological abnormalities that could be there as the disease mechanism, that may include one or more of autoimmune or inflammatory or degenerative or endocrine or metabolic or cancer mechanisms.11:20 Professor Louise Baur AM
Then there's an illness which typically has signs and symptoms that are are an expression of that organ dysfunction. It's often very characteristic for that disease directly linked to the pathophysiology and typically evolves over time. If we think about diabetes, there are in presumably, they're often infectious, certainly, environmental, certainly and genetic and many other factors that contribute to the development of diabetes. There are a range of known disease mechanisms, so including insulin resistance and impaired beta cell function and autoimmune abnormalities, and when it presents, it typically has issues such as fatigue or polyuria or polydipsia or weight loss or weight gain. Of course, over time, there'll be complications such as retinopathy or blindness or kidney disease or heart disease.12:24 Professor Louise Baur AM
But what about obesity? Obesity has lacked a definition of illness. We do understand the causes of obesity, or we have a reasonable understanding of many of the causes. We have increasing knowledge about the specific pathophysiological abnormalities. But it's been really hard to define what is the illness of obesity. We tend to talk about it in a different way from talking about diabetes or cancer. Now, if we think about what is an illness, it's a subjective and objective experience of disease, and diseases are fundamentally characterised by the ability to cause illness. Illness is essentially the identity of a disease that allows the clinical diagnosis, and it allows a differential diagnosis from other problems.13:16 Professor Louise Baur AM
We can see here cartoons of 2 figures, both of whom are of large body size, one of whom seems to be in good health, the other of whom seems to have health problems. One would be seen to not have an illness. The other may well have an illness related to that high body size. We'll come back to those people later on. when you have other complex diseases, a number of them have agreed constellation of signs or symptoms or manifestations that go towards making that diagnosis. If we think about systemic lupus erythematosus, the American College of Rheumatology have agreed definition, agreed criteria for the diagnosis, so you can see some of those there, and you need 4 or more of those criteria to have lupus, or think about clinical depression, which is actually quite common in our community, in many communities around the world, and the DSM 5 criteria have a range of clinical criteria that need to be met, and you need to have 5 or more to be diagnosed for the confirmation of clinical depression. This sort of background was important in thinking about obesity.14:45 Professor Louise Baur AM
The aims of the Lancet Commission was to define clinical obesity and identify objective criteria for its diagnosis. We conceived obesity as a clinical obesity as a state of illness that reflects a substantial deviation from the normal functioning of tissues, organs and all the organism as a whole. We wanted to do this to inform decision making of clinicians and policy makers, and perhaps to prioritise clinical interventions and public health strategies. This was led from King's Health Partners in London, and there was a globally representative multidisciplinary group of experts, including academic clinicians specialising in obesity care. I was one of them. I was one of the 3 paediatricians in that. But I'm here today talking not with a paediatric hat on. There were scientists who worked in the area of obesity. There were public health specialists, patient representatives and WHO officers. The whole process took quite a bit of time. You'll see in the next slide, just how long. We initially met online and had presentations by guest experts and commissioners, and we had surveys to help us understand about what these issues that we're going to do could be. We then had a Delphi like consensus development. This is where you ask people, what do you agree? You know, do you agree with this statement, with this one, that one, etc, and we had 3 rounds of that. We had to have everybody respond for those and each time they were refined. The whole idea was to get 90 to 95% agreement by the commissioners in each of the statements. We then sought feedback from patient organisations around the world and various professional societies. Then time spent writing a report, a lot of peer review, and then we launched the results in mid January this year, and then there have been regional launches and dissemination.17:07 Professor Louise Baur AM
Now all of this sounds like it was very efficiently done, but the concept originally arose about 5 years before the actual paper was done, and you can see that we started proceedings in mid 2022, we had a bit over a year later, consensus document we support, and then it went for peer review the end of 2023 and then accepted towards the end of last year, and then published early this year. Quite a long period of time that you need to be future focused and not want immediate gratification if you do research or clinical work often.17:49 Professor Louise Baur AM
Let me just go back to the figures that I taught the 2 people that I told you about before. Here is Jack with a BMI of 37 that's kilogrammes per metre squared. He has symptoms of fatigue, shortness of breath on exertion. He has recurrent bilateral knee pain. He has reduced mobility. He has heart problems. He has reduced diastolic function. He's got lung problems, a restrictive pulmonary defect. He's got bilateral pain, knee pain and stiffness. He doesn't have diabetes, but he has his other health problems. He's currently unemployed. He used to work for a moving company, but he was no longer able to run his jobs duties, so he had to leave his work.18:35 Professor Louise Baur AM
Then there's Maria, who also has a BMI of 37 and who's basically well on her medical assessment, her blood test showed mildly raised triglycerides, but no other health issues. She's currently employed, and she looks after her family. She has a busy working and family life.18:58Professor Louise Baur AM
Who has the illness? Does she have the illness? And so this was part of the question. This helped us think through these issues.19:07 Professor Louise Baur AM
I want to just have a little side step now to think about body mass index, or BMI, weight over height squared. This has been used for many decades as an epidemiological tool to compare populations. You look at differences between countries, this country versus that, or changes over time, so longitudinal changes, or differences between males and females and I'm going to show you now 2 maps showing population prevalence of obesity in adult women in 1990 and most recent. This is a women living with obesity. This is from the global obesity observatory of the World Obesity Federation, which is a really good website, I might add. Here, the darker the colour, the higher the prevalence of high BMI. This is based on a BMI of 30. We can talk about how appropriate that is for some populations later on and what you can see here is in 1990 there was a higher prevalence of high BMI in the USA, parts of South America, parts of the Middle East, parts of Australia, New Zealand and Europe. But now just look, there are also data that they weren't present, but look now at what's changed over time to the most recent data.20:43 Professor Louise Baur AM
First of all, there are more data available, but there's also more darker colours, and so we're seeing this in many parts of the Americas, in North Africa, but also South Africa, in Australia, New Zealand, parts of Europe, there's actually parts of Asia where this is a higher prevalence. What you can't see here, because the countries are so small to see, is that it's particularly an issue in the South Pacific and the Western Pacific region and in the Caribbean, where there's very high prevalence, just based on this BMI. That's telling you some things have changed over time.21:26 Professor Louise Baur AM
BMI can be useful as an epidemiological tool to tell you something must have changed over time. But it's also used clinically to categorise individuals into weight status groups into underweight, healthy weight, overweight or obesity. Of course, as Steve has pointed out, if we're trying to get a sense of particularly body fat, maybe there's problems with that. Maybe there are limitations and there are, indeed limitations if you just use BMI to get a sense of obesity when it's used clinically.22:06 Professor Louise Baur AM
If we look at the person on the left, who's an elite athlete, who has high muscle mass, they may have a high BMI, but they don't have a high body fat, and of the 2 people on the right hand side, both of them have a high BMI, and they do have high body fat. One of them, Jack on the right, has a lot of health problems that are seen to be related to his high BMI. The woman on the left, Maria, lives a very fit and active life. She doesn't have health problems linked to her high BMI and her high body fat at the moment.22:51 Professor Louise Baur AM
How do we distinguish between all of these? In the Commission, we had this concept here, and I'll just walk you through that. You need to work out if somebody has high body fat, and we can come and talk about that in just a little while. But if you have excess body fat, there are people with no ongoing illness, they may have a high body fat, but if there are any, there are almost no changes in alterations of cells and tissue, or not too many changes in their organ structure. They have no clinical manifestations of health problems, versus those in the red zone, where there are now starting to be alterations of organ function and indeed end organ damage. Where there are signs and symptoms and alterations of day to day activities and health complications. Clearly, it's not one or 2 other it's a gradation. But I want you to get this idea of excess body fat with no ongoing illness, and excess body fat with an ongoing illness.24:05 Professor Louise Baur AM
The commission was thinking about this. What were our recommendations? Well, first of all, we think it's really important to work out if someone is presenting for clinical treatment, and you think this may be an issue, or if there is to work out in an appropriate way whether someone has excess body fat or an abnormal fat, body fat distribution. I might add that all of this needs to be done in a very thoughtful, consultative, non stigmatising manner. You can ask me questions about that later on. It's not the main focus of my talk today, but I'm very happy to discuss that.24:46 Professor Louise Baur AM
We said, as general recommendations, is there body fat? You say yes, you can continue to use BMI, but please include some measure of fat distribution there. If you have access to a gold standard measure of body composition, such as DEXA, dual energy X ray, absorbed geometry, and you can see a photograph of one from the kids hospital here, then please use it. We wanted to be pragmatic. We we would love to live in a world with no resource constraints. That's why I put all those exclamation marks. Because ideally, you might use a gold standard measure of body fat and of fat distribution, such as dual energy X ray absorb geometry. We have one at the kids hospital here at Westmead, where I work, but we only ever use that for research. We never use it clinically or not routine clinical work. However, in the real world, we use BMI as a screening tool for high body fat, and we would recommend, we actually would really insist that you use an anthropometric measure of body of fat distribution, such as waist circumference or waste to height ratio, still imperfect, still not based on body fat measure, but pragmatic, or if you have a very high BMI, and we said, if your BMI was greater than 40, then we could probably assume that you had a high body fat.26:12 Professor Louise Baur AM
These recommendations that we came up need to work globally with most environments in the world being very resource constrained. It was interesting with this group of experts, those who came from elite institutions with enormous amounts of money seem to have very different views from those who worked, I would say, in a more reasonable setting. I just want to highlight most environments in Australia are reasonably resource constrained as well. Then I've just been really reminded in recent weeks that there are countries around this world where there are problems with access to weight scales, height stadiometers in many places, and trained clinical staff who can do these measures effectively, accurately, with precision and in a way that is non stigmatising. Plus, I was reminded that in some countries, there may have cultural barriers to assessing waist circumference, especially in women and of course, it's an issue that I as a woman tend not to have in dealing with female patients, but just highlighting some of the challenges in being able to do this in real world settings.27:30 Professor Louise Baur AM
The question is, yes, there's a high body fat, but is there preserved health, or is there ill health? Is it a Jack or a Maria? This is where taking a clinical history, examining the patient and considering investigations for potential health consequences is really important. I love this because I was trained to do this as a medical student, and I love training my medical students to actually do good old fashioned medical things, listening to the story of a patient examining them, considering investigations as needed. Because if there aren't health problems, this is what we would call pre clinical obesity, and if there are, then that is what is clinical obesity. I want to highlight that it's not just organ dysfunction, but limitations of day to day activities that need to be taken into account.28:26 Professor Louise Baur AM
Now, what were some of these diagnostic criteria for clinical obesity? Here's the cartoon of the adult. We spent a lot of time trying to work out what were the 18 diagnostic criteria for clinical obesity for adults. These included, for example, if you think about upper airways apnea or hypopnea, so during sleep due to increased upper airway resistance in heart disease, we might think about heart failure with reduced ejection fraction due to left reduced Left Ventricular Systolic function. We talked about chronic or recurrent atrial fibrillation. In terms of liver disease, we talked about metabolic dysfunction associated stereotypic liver disease with fibrosis renal disease, micro albuminuria and so on. Just want to highlight so quite a number of things there, including lymphatic abnormalities, musculoskeletal abnormalities and so on. Always recognising that there would be people for whom there were substantial age adjusted limitations of daily living.29:45 Professor Louise Baur AM
In my paediatric practice, I have some patients who find it hard to actually just be able to go to the toilet and wipe themselves in an appropriate way afterwards, and because of their very large body size that would be included. For children and adolescents, we came up with 13 criteria. Some of the adult ones were not relevant in childhood or adolescence, and there are some specific musculoskeletal abnormalities in children and young people where you've still got growing bones, and with the impact of increased weight on joints or on bones can actually lead to musculoskeletal abnormalities, and again, there were limitations of day to day activities. So people, for example, continents, toileting, bathing, dressing.30:42 Professor Louise Baur AM
That's it in a nutshell. But I've been asked lots of questions, and we tried to address these in our paper. Does this mean we should not use BMI in assessing people with obesity, possible obesity? I would recommend, and we do recommend, that we continue to use BMI as it's a useful and simple screening tool, screening tool, but it's very limited on its own, and we should supplement it with anthropometric measures of fat distribution, or if you were able to get body composition measure. Plus you should clinically assess the patient for obesity related health problems, nothing like taking history and examining a patient.31:26 Professor Louise Baur AM
We're also asked, why didn't you include type 2 diabetes in the criteria? In fact, some people said this very loudly to us, why weren't we concerned about diabetes? In fact, we were, and we spent an enormous amount of time talking about this, but we didn't want to define clinical obesity based upon the sole presence of another disease, including diabetes. What we have included in the diagnostic criteria is the cluster of hyperglycemia, high triglyceride levels and low HDL cholesterol, so what you might call like the metabolic syndrome. But it is interesting, and when I met recently with one of the other paediatric commissioners, we both felt that if we had a young person who had a high BMI, a high body fat, and they had type 2 diabetes, they had clinical obesity without going any further. But that's an issue that we could talk about later on.32:26 Professor Louise Baur AM
Also, why weren't we concerned about mental health problems? Why weren't they included in the diagnostic criteria and petition, particularly depression? Because they are certainly linked. Again, we had much discussion about this, and my view changed as we talked about this, because I originally wanted it included, and there's a bi directional association between obesity and depression, one can lead to the other, and vice versa, and that makes it difficult to have obesity.32:56 Professor Louise Baur AM
Depression listed solely as a consequence of obesity. Further, we know that treatment of obesity does not necessarily, in and of itself, lead to improvement in mental health if the mental health problems are themselves not being addressed at the same time. We see this with, for example, some of the long term follow ups of people with bariatric surgery. We were also asked about existing obesity staging strategies. How are they different? These in fact, are very useful in clinical practice. However, they're not aimed at the specific rationale for the Lancet Commission was what specifically defines clinical obesity as a disease, and we would, in fact, encourage incorporation of staging systems into the broader clinical assessment of people with clinical obesity.33:47 Professor Louise Baur AM
Here, for example, the Edmonton Obesity Staging System from Canada, which looks at, you know, you can have stages, zero, 1 2, 3, or 4, and it looks at things such as medical problems, mental health problems, or functional problems, and you can stage people that way. Or The King's Obesity Staging Criteria have quite a number of criteria, airway BMI, cardiovascular diabetes, etc. There's stages 0,1,2, or 3 and the idea is, the higher the number of stages that you've got, the worse the disease, the more likely you're going to intervene and do things. They they assess overall risk from obesity and other health problems, but they don't describe a specific illness alone.34:36 Professor Louise Baur AM
Then, of course, we're asked about what specific cut points for BMI and for health problems. For BMI, we did not specify those in the report, but the supplementary tables provide a summary of potential BMI cut points in people of different ethnicities. This was really important, and it's an important area of ongoing work, because as we would know, particularly here in Australia, where we're so multicultural, and the region where we are that people from particularly South Asia, East Asia, Southeast Asia, and people of Aboriginal and Torres Strait Islander backgrounds tend to develop problems such as type 2 diabetes at a lower BMI than people of, say, Northern European background, they are more likely to have an increased abdominal fat at a lower BMI.35:32 Professor Louise Baur AM
This is part of the idea about being very careful about that. I might add, in contrast, people from Pacific and Maori backgrounds tend to develop their risk for diabetes and so on at higher BMI than people of Northern European backgrounds. You can't just use the same BMI and have the same thinking about it each time.36:01 Professor Louise Baur AM
What are the ethnic specific differences in BMI cut points? Well, this is a bit of a challenge. The WHO has tried to look at this over many, many years, and this was a commission that was an expert consultation that was published just over 20 years ago, where they looked at what were the BMI cut points for Asian populations and they came up with a number of possibilities here, but they ultimately weren't redefined.36:32 Professor Louise Baur AM
What's interesting is that different countries, India, China, other, some other Asian countries, have somewhat different BMI cut points for their individual countries. This is why I think it's actually very useful to go. You need to know what the cut points are if you're going to talk about it at an epidemiological level. But why? Being able to think about health problems also is very important in terms of making clinical decisions. Let's go and think about what this might mean for clinical care or public primary prevention.37:10 Professor Louise Baur AM
Let's think again. Here we have Maria on the left and Jack on the right. They both have high body fat. In the sense of high body fat obesity, they both have that, but Maria has preserved health, and we would say that she has pre clinical obesity, whereas Jack has health problems, and he would have he has an illness, and we would say he has clinical obesity. There are implications here for what might be done in terms of level of intensity of treatment, if you are going to do that and and so on. Let me just take you so someone such as Maria, we may have said, would need monitoring, and potentially may want to have prophylactic intervention. I'll come and talk about that, whereas someone like Jack may well need disease treatment and therapeutic intervention.38:13 Professor Louise Baur AM
Let's think about clinical obesity to start with. Its intent is to aim for remission of clinical manifestations of obesity. Think of obesity as a long term condition. It's say, not an acute care once treated, that's its problem. We're aiming for long term rehabilitation, long term remission and the treatment options are not mutually exclusive, and they may be used individually or combined, so in inverted commas "lifestyle interventions" or "support for behaviour change."38:48 Professor Louise Baur AM
I have some challenges with the user lifestyle, but also increasingly new options for pharmacological therapy, as well as long standing options for surgical treatment. We can talk about access issues, but these are all part of a suite of options available. What we would say is that when you have clinical obesity, you need timely access to evidence based treatment and availability will depend on, when we're thinking globally, but even within Australia, on local and regional policies and resources. It's a very common problem, and there are challenges with resources in almost every country.39:31Professor Louise Baur AM
What about if we're thinking about the Maria's of the world, pre clinical obesity? Well, it's really important, broadly to potentially talk with that person about risk reduction, so that somebody such as Maria, if she had a high risk family history or if she had other concerns, you would be listening to her and then planning options. For potentially more intensive therapy, depending on what you found. But as it is at the moment, she doesn't have any major health problems.40:09 Professor Louise Baur AM
What about public health policies? Well, these clearly should be evidence based. It's really important that we don't blame individuals. Obesity is not due to a failure of personal responsibility. It's a physiological response to what is, in many cases, a pathological environment known as early 21st Century Australia, early 21st century world. For an individual, you may elect, if they've got low risk, screen and monitor them over the time. If they're cool, that's fine, But if they're high risk, for some reason, they may require a therapeutic intervention, such as the ones I was discussing earlier.40:55 Professor Louise Baur AM
Questions I've been asked, does this mean that people with pre clinical obesity can't be offered more intensive therapies, and the whole answer is not at all. It will depend upon risk and change over time and the person's preferences. There's a concept of a graduated level of risk. It's not simply yes or no. It's not Maria there and Jack there. It's about a graduated level of risk, and I think it may be especially the case in children and adolescents, where they've got a whole lifetime ahead, where you may well want to intervene earlier to avoid development of long term health problems.41:35 Professor Louise Baur AM
Another question I've been asked is clinical guidelines for drug therapy and bariatric surgery in many parts of the world, often use straight BMI cut points above 30, above 35, above 40 to determine access to therapy. What are the implications for that? Well, the Lancet criteria imply a broader assessment when you're dealing with individuals of body fat and fat distribution, as well as health consequences before you make a decision about treatment options. While this can be done at an individual clinical level, that's okay, but it can be challenging to implement at a health policy, a health service level where people love cut points, where BMI cut points are often used pragmatically, and this is a challenge, because we're actually saying maybe we need to do this broader assessment. In fact, we should be doing this broader assessment.42:31 Professor Louise Baur AM
As I'm nearing the end of my talk, the Lancet Commission of the concept of a clinical obesity offers a way of thinking of obesity as a disease, or when it is a disease, a clinical obesity is a disease. However, at the same time, obesity may also be a risk factor for a range of other health problems that's no different from a range of other diseases, eg. diabetes, is it so which everybody acknowledges is a disease, is itself also a risk factor for heart disease and for chronic kidney disease.43:10 Professor Louise Baur AM
I've got 4 areas I'd like to suggest for future areas of work, we're using existing epidemiological data that rely solely on BMI trying to get a sense of prevalence of clinical obesity or or pre clinical obesity, but they're limited by incomplete historical information. People didn't collect all the information that was needed. Can we update those to reflect the range of clinical presentations of obesity by using measures of broader health status, so that we can ultimately work out what is the population prevalence of pre clinical and of clinical obesity in different populations.43:52 Professor Louise Baur AM We need better work, more work, to stratify clinical obesity and better identify disease subtypes based on clinical presentation or pathophysiology, and also, many people with preclinical obesity may only require risk mitigation, but others will require more intense intervention. How do we identify these people, and how do we modify our models of care and treatment pathways in light of the new criteria. These are all really important research and practice questions. Steve, more grant applications coming your way as people try to work out these issues.
44:35 Professor Louise Baur AM
But I want to just take a step aside and think more broadly about obesity, and I'm happy to take questions on these issues later on as well. I want to highlight the issue of the 3 zeros for obesity. Now, these were inspired by the UN AIDS 3 zeros. The World Obesity Federation is working on refining these. I want to ask us, can we imagine a world where there is zero stigma towards people living with obesity, zero barriers to accessing really good clinical care, and zero increase in prevalence? Big question marks, big queries, and a lot of work is needed to try to address these.45:21 Professor Louise Baur AM
I want to encourage you to read the paper. It's freely available, and there are fantastic linked infographics, as you may have picked up. There is much work that lies ahead as we work on these issues and we work out the implications of clinical obesity, and no doubt, do further refinements over time. Thank you. Just stop sharing now.45:47 Professor Steve Wesselingh
Thank you so much, Louise, it was terrific. Really, really terrific and such a big, big issue. We've already got lots of questions, and I actually have a whole lot of questions too. But I might go to the questions online first.46:07 Professor Steve Wesselingh
Joy has asked, how can we account for the major role of social determinants, food, environment, housing, stress, when labelling obesity as a disease?46:18 Professor Louise Baur AM
You highlight really important issues here. Clearly, there are major environmental and social determinant factors influencing why some people develop obesity and others don't. You remember I talked before about obesity being occurring when there's genetic predisposition that becomes manifested in a given environment. Particularly if you live with social deprivation and other challenges. I might add, this is no different from the same for heart disease or diabetes or other very common non communicable diseases where there is very strong genetic and other biological processes causing these diseases, but where they become manifested or become more difficult to treat.47:09 Professor Louise Baur AM
In places where people live with, say, social disadvantage, or live in parts where there may be more challenges for accessing good care in remote and regional parts of this country, poverty is really, really important to try to address. I don't disagree with you. Those issues doesn't mean there isn't a disease, it just means it's made worse by those social determinants of ill health. I hope that's a reasonable answer for you. I share your pain.47:39 Professor Steve Wesselingh
We also have a question from Ruth and Cameron, which actually are addressing, I think the same thing.47:45 Professor Steve Wesselingh
Ruth has asked is there an effort to remove labels for different BMI numbers, eg. 30 plus equals obese.47:54 Professor Steve Wesselingh
Then Cameron talks about the Queensland ambulance department use of BMI, and the fact that a student could satisfy all criteria, but still be refused placements because their BMI exceeds a certain level, exceeds a cut point. I think that does go to a lot of what you've talked about. But could you comment about those 2 questions?48:23Professor Louise Baur AM
I think that. I think yes, labelling. I think it's you. I talked about the epidemiological approach, which I think can tell you things, what happens over time. Why is this population in this country different from that population? That can tell you a lot, but when you're talking about individuals, I think you need to come down to clinical assessment. It's just way too easy to just label people in terms of their BMI, and I hope I was just reinforcing that issue.48:53 Professor Louise Baur AM
Of course, there are big mostly individuals who have good health, and they're even maybe people with high body fat, who may be in very good health, who may well be able to do a heap of things that people have more in inverted commas "normal BMI" may not be able to do. We shouldn't just judge people based on their BMI. We don't know their history. We don't know their body composition or anything like that. I agree with you. I think there should be moves towards more nuanced approaches to things.49:24 Professor Louise Baur AM
I might just say I particularly don't like labelling people as the word as obese, because that's an adjective I like to use person first language. If I'm talking about it clinically, I'd say a person living with obesity, rather than an obese person and things like that, just as we would with other diseases. Just I'm sure you would agree with that. Thanks.49:48 Professor Steve Wesselingh
Thanks for that and I just encourage people to put more questions up on the Zoom link there. I guess maybe I just ask a question about in aged care, I guess so when we look at people who are becoming elderly and frail and there does seem a correlation between frailty and actually ill health and death with low body weight. What are we saying to people who are entering, we're getting older, like some of us, and do we need different criteria? Because there does seem to be evidence that entering that period of your life, you might have an advantage if you carry a bit of extra weight.50:35 Professor Louise Baur AM
Well, first of all, just reminding everyone, I am a paediatrician rather than a geriatrician, but I have got some broad concepts here.50:43 Professor Louise Baur AM
Part of this may relate to the idea of you can have sarcopenic obesity as well. This has been some of the anxiety so it's not just your weight, but actually, what is your body made of? Your body composition. What is the amount of lean tissue that you have muscle tissue, as opposed to body fat tissue? I suppose, ideally you'd like to enter go through adulthood and enter older age with a healthy BMI, with good lean tissue, relatively low body fat in terms of, you know, on the lower side, so you're not high, high risk for health problems. Then to enter your elderly area, sorry, I'm not saying this well, into older age with good muscle mass, you're being physically active. You've got resistance and cardio respiratory activity in your daily life, and you're eating well, that would be the ideal. One of the challenges in being frail is certainly a risk for lots of problems, and sometimes having obesity as you enter can actually mask some of that muscle and musculoskeletal frailty as well. I'm not answering that very well, but part of it is trying to optimise your body composition at whatever age you are, if you have that opportunity to do so.52:14 Professor Steve Wesselingh
Okay, thank you so Rosemary Stanton has asked should we have better labelling information on foods, more emphasis on the problems of ultra processed foods? Professor Louise Baur AM 52:26 Thank you for one. Thank you Rosemary for that great question ad you are one of my public health and nutrition heroes for decades. Thank you Rosemary for that question.52:35 Professor Louise Baur AM
Yes, we should be doing this. I think we're all aware of the the rise of ultra processed foods, one of the consequences of that, for example, these sort of long shelf life foods with high fat, sugar and salt, foods that my grandmother and possibly the great grandmothers of many of you would not recognise are associated with decreased protein intake. They're designed to be highly palatable and they're not nutrient rich. There's lots of issues like that. I agree that we need better health labelling of foods, so that, and you shouldn't have to have a PhD in nutrition, very good eyesight and lots of time available to you to be able to work out what it is that you're eating. It should be really obvious to most people what is there. That is an issue that many public health advocates are really wanting to do. We want to be able to give information to the consumer so they can make healthy decisions quickly. Of course, one of the challenges too is that high quality foods, high quality nutritious foods, are often more expensive and shorter shelf life, often less available to people, and that's not good and particularly a challenge in remote and regional parts of our country. Thanks.54:08 Professor Steve Wesselingh
There's a couple of people who wanted to know about GLP-1 agonists. Are we going to see that have a big impact on the field? Will we have a situation like statins, where we have a significant portion of the population taking GLP agonists.54:27 Professor Louise Baur AM;
Well, statins, which are used for the treatment of hypercholesterolemia, I know that when I was doing my postdoc over 30 years ago, they were because I remember talking, listening, reflecting on this with people. It was used essentially just for people who'd had, like, for example, a heart attack. Were used in very specific circumstances because they were expensive.54:54 Professor Louise Baur AM
But as experience grew with those, as new versions of those drugs became available as competition decreased the price, as evidence grew around the effectiveness in terms of many other health benefits, they became widely used. Not just for people who've had a heart attack, but in order to stop people being at risk of a heart attack.55:18 Professor Louise Baur AM
I think we're going to be seeing something like this with the GLP-1 receptor agonists or incretins, not just those, but similar medications. We've got about 10 years of experience, initially in people with diabetes, but now with people with obesity in their use, they really have been quite amazing, when used appropriately. People with clinical obesity, in terms of the trials show improvements, not just in weight status and body composition or risk factors for heart disease, but in terms of sleep apnea, musculos, people needing surgery for their osteoarthritis, their liver disease, development of various heart failure and many other health problems have been improved. These are very interesting medications, and I think when used in the treatment of people with clinical obesity, they can be part of a tremendous of a really changed armamentarium for treatment.56:27 Professor Louise Baur AM
For many years, most of what we had available was support for behaviour change, and there is a subgroup of people who really respond well to that and need that, who can do that. But for many people, there may be an initial change and improvement in weight status, but then there's a rebound effect, because this is hard. You live in the 21st Century. It's really hard to keep on making those changes. In fact, our body set point brings out, tends to bring our body fat back to the same level.56:59 Professor Louise Baur AM;
Bariatric surgery, for which there is very good evidence, but is really only appropriate at those with more severe obesity. To have new pharmacotherapy is fantastic, but we have to use those well. We're starting to get a sense of it, they work. They are useful for many people. They do have side effects, which mean that they may not be appropriate for some people but we're waiting to see as new medications become available. People are trying that there's new versions of these that are in phase 3 trials. We have 2 major types that are available to zepetide and semaglutide that are approved for use in people with obesity in Australia. None of them are available or supported, sorry, none of them are supported on the pharmaceutical benefit scheme for people with obesity in Australia. I think that over time, that will change as medication costs come down as more evidence comes in about the cost effectiveness of these.58:04 Professor Louise Baur AM;
But don't think that these are a simple solution. They need to be given within the context of wraparound support for the other health problems that people have, and for support with changes in diet and physical activity. It's really important if your diet, if you're on these medications that, amongst other things, decrease appetite, it's really important that every morsel that you eat is nutrient rich, and it's also important at the same time that you are able to exercise and preserve your muscle mass. These aren't something to be taken lightly.58:41 Professor Steve Wesselingh
Thanks so much. We are getting to the end of time, and actually, when I asked for more questions, I got so many.58:46 Professor Steve Wesselingh
We will give the questions to Louise, and if Louise doesn't mind that, she could answer those questions, and we could get back to you, but I might finish with the last question, which is a very long question, I'll try and summarise it. But essentially, the question is that this person's made some observations around rural and remote traditional and First Nations lifestyles, and asked the question whether moving away from traditional lifestyles to what let's call Western lifestyles, or ultra processed lifestyles, is the wrong direction, and we perhaps should be looking at some of the benefits of more traditional lifestyles.59:33 Professor Steve Wesselingh
I think I've got that question right. But Louise, would you like to comment on that?59:37 Professor Louise Baur AM
I very much agree with that. In fact, a wonderful person called Kerryn Aday who, who died fairly recently, did some amazing work as a nutritional scientist some years ago, where she accompanied some Aboriginal men who had high weight and health problems and observed them living, going back to a traditional lifestyle, eating off the land, things like that, and was able to document dramatic improvements in diabetes risk, heart disease risk and so on. I still remember hearing about that and just highlighting, again, how important those traditional lifestyles, traditional ways of doing things were for the health and well being of not just the Aboriginal people, but that of all of us. So yes, I agree that move away from traditional lifestyles can be a tremendous problem for so many people.1:00:36 Professor Steve Wesselingh
I think we'll end on that. I'd just like to thank you, Louise for a fantastic talk and I'd like to thank the audience for terrific questions and as I said, there are more questions, and we will make sure Louise gets them and and that she can answer those for you.1:00:57 Professor Steve Wesselingh
I'd like to thank everyone for joining us for our last Speaking of Science for this year, and just mentioned that actually, this is a new initiative for NHMRC and and I think it's going really well. We've had fabulous speakers. We've had great turnout, really good questions and and we definitely will be continuing this in the new year. We just encourage everyone to look out for the next Speaking of Science in February 2026, but we're also interested, if people want particular researchers or experts or topics, please let us know and we can see what we can do.1:01:39 Professor Steve Wesselingh
There's a recording of the webinar, which will be online shortly. We encourage everyone to have a look at that. Thanks again, Louise, dealing with this really, really important problem and a fabulous talk about a really complex area. Thanks everyone else, and enjoy the rest of your day.End of transcript.