Melanie Cole, MS (Host): Welcome to Better Edge, a Northwestern Medicine podcast for physicians. I'm Melanie Cole. And joining me today is Dr. Robert Kushner. He's a Professor of Medicine in Endocrinology and Medical Education, specializing in Obesity at Northwestern Medicine. As a member of the Lancet Diabetes and Endocrinology Commission, Dr. Kushner is here to discuss their newly-released set of global clinical recommendations that were established to redefine clinical obesity and how it's diagnosed, A Better Definition of Obesity: New Global Guidelines.

Dr. Kushner, thank you so much for joining us. As we know, defining obesity is not really straightforward. Using body max index, as you and I were just discussing, alone may miss out some unhealthy individuals, and mislabel others. Can you tell us what has historically been the defining criteria for obesity, why this needed updating, and how excess body fat can really impact a person's organ health, daily functioning, quality of life? 

Dr. Robert Kushner: We currently define obesity, both on population basis and individual basis, based on body mass index, or BMI, which is weight over height squared. It does not take into consideration your body fat, the distribution of your body fat, and more importantly, whether the excess body fat causes any harm to your health. So, it has multiple limitations. And there's been a call for moving beyond BMI for quite some time now. And that's exactly what the commission report addressed.

Melanie Cole, MS: I'm so glad about this. As an exercise physiologist for 35 years, way back when, I would look at somebody and say," This is a much more muscular person." I mean, I look at my son who's a gymnast and his weight versus his height, it just doesn't correlate. So, I'm so glad we're talking about this, Dr. Kushner. So, give us an overview of the new global clinical recommendations that were just released to redefine obesity and explain why you're doing that, the difference between the two new diagnostic categories that have been identified, clinical obesity and preclinical obesity, how these definitions are changing the approach to patient management.

Dr. Robert Kushner: You know, we've defined obesity for quite some time now as excess body fat that causes harm to health. But we've never really clearly identified obesity beyond BMI and what is the harm to health. So, the Commission tackled those two parts of that statement. The first is what is obesity? We reaffirmed that BMI is insufficient and has limitations, so we recommended that another measurement be added to BMI in order to identify excess body fat. We identified three additional anthropometric measurements that should be done in every individual before you identify them as having excess body fat. And what we are recommending is that you add either a waist circumference, a waist-to-height ratio or waist-to-hip ratio. These are measurements of size that are highly correlated with body fat. So, that's the first part of that definition.

The second is, what is the harm to health? So, one can have obesity, which is excess body fat, but have no harm to health. In other words, there's no signs or symptoms that the fat is causing organ impairment or illness to the individual or any limitations in daily activity. For that person, we would say as a new term, they have preclinical obesity. They have obesity, but no harm to their health. In contrast, someone can have obesity, which is excess body fat, but you are now having signs and symptoms or reduced daily activities that are directly related to having excess body fat. Examples would be chronic knee or hip pain, shortness of breath, urinary incontinence, headaches or snoring due to sleep apnea, or abnormal blood tests of elevated blood sugar, triglycerides, and a low HDL cholesterol. These would be signs or symptoms directly related to body fat, and we've introduced a new term for this condition, which we call clinical obesity.

Melanie Cole, MS: Thank you for sorting through that for us. Now, Dr. Kushner is a member of the Lancet Diabetes and Endocrinology Commission. Describe the process that was taken to arrive at these new definitions, what you just described. And tell us how it proposes to use objective measures of illness based on individual risk factors.

Dr. Robert Kushner: Melanie, it was an over a two-and-a-half-year process of monthly Zoom meetings. We had 58 commissioners who were experts in obesity, including individuals with lived experience of obesity, who participated on a monthly basis in order to come up with these guidelines. It was developed by consensus. And we had various statements that we voted on, separating out how do we define obesity and how do we define these new terms, and that is preclinical obesity and clinical obesity.

We took a pragmatic approach. That is, we did not want to use methods or systems that could not be generalizable around the world. So, for example, we did not call for a mandatory measurement of body fat by bioimpedance or by DEXA, although if you have it, it's fine. But we took a more realistic, practical approach by adding another anthropometric measurement.

Melanie, it is going to take time in order to implement these recommendations and have them used in the clinic. Our sole focus of the commission was to move beyond BMI and to start the conversation of how do we better identify individuals who truly have excess body fat, not just increased weight, which was BMI, and to start identifying individuals who had very early signs that that excess fat is impairing their health, and that's where the signs or symptoms or blood tests come in, so that they can obtain treatment and support early on. And to separate those individuals out who have excess body fat but no harm to their health, we call that preclinical obesity, where they could be monitored and have increased attention to their health because they are still at risk of having increased problems as time goes on.

Melanie Cole, MS: We're learning more and more, and we're hearing more and more about recognizing obesity as a disease, Dr. Kushner. So, what do you believe are the most significant implications of redefining clinical obesity as a chronic disease? Tell us how these guidelines might represent a significant shift allowing clinicians to identify those in need of treatment as opposed to just another risk factor.

Dr. Robert Kushner: That's a very important point, Melanie. Oftentimes, we talk about obesity as a gate through condition. And that is if you have an excess body weight, you are at risk of developing things like cancer, heart disease. And what the guidelines identify is that the excess fat itself can cause problems.

If you have what we now call clinical obesity, so you have excess body fat and having signs and symptoms of either organ or impairment or reduced activities of daily living, you should seek treatment early. From a population and clinician point of view, we hope to use our resources more effectively by providing care to individuals in need and not ovover-treatingndividuals who may have an elevated BMI but have no harm to their health.

Furthermore, we're hoping that this would reduce the stigma and bias that has really fallen upon obesity., shining a light on the fact that this is a disease where we could identify how fat is impairing one's health, and it's not just lack of willpower or not trying hard enough, society will take notice, reduce stigma, and allocate resources to those individuals in need.

Melanie Cole, MS: I'm glad you brought up stigma, Dr. Kushner. So, I'd like you to speak about how physicians should approach treatment planning differently for patients with clinical obesity versus those with the preclinical obesity. But also, please, speak to the fact that the stigma also exists within the medical community. And so, some other physicians, if an obese person is going to that physician, might really kind of grab onto that stigma as well. So, I want you to speak to these providers in how they can work with these patients to free them of that mentality so they can best help their patients.

Dr. Robert Kushner: It's very clear that obesity is a biologic disease. It's not solely due to lack of willpower and not having enough motivation. We also know that giving recommendations of moving more and eating less is not going to work. By identifying specific signs and symptoms or blood tests that are related to obesity, we hope that clinicians can better identify individuals who are at risk early on and allocate resources to these individuals at the beginning stages of signs and symptoms instead of waiting until medical problems move down the road and they develop more serious medical problems.

Melanie Cole, MS: What about challenges in implementing this new diagnostic framework within the current healthcare system? Do you see any?

Dr. Robert Kushner: The focus of the commission was to move beyond BMI and to start the conversation to better identify what is obesity and to introduce new terms of preclinical obesity and clinical obesity. To have this being implemented and generalizable in the clinic will take time. We expect there to be many more conversations and recommendations, particularly regarding signs and symptoms of how we define obesity. Our current coding system, which uses ICD-9, still uses a BMI classification of 1, 2, and 3. Our recommendations for treatment, particularly pharmacologic treatment, still requires an elevated BMI with an additional comorbidity. We are hoping that these recommendations will reframe some of the decisions being made now regarding who warrants treatment, and to directly provide care to those based on elevated BMI, and having these signs and symptoms that signify clinical obesity.

Melanie Cole, MS: Dr. Kushner, what important work you are doing, and I thank you so much. As we wrap up, how do you see this new classification of obesity impact future clinical trials, research initiatives? Give us a blueprint for future research, but also what you hope, what you want to see happen with these kinds of initiatives.

Dr. Robert Kushner: It's a very important insightful question. All of our trials with obesity are based on enrolling individuals with an elevated BMI who have risk factors, and we are changing the conversation to those that have obesity and have direct implications of causing clinical obesity.

I can envision as trials go forward that we will be enrolling or at least looking at the effect of these interventions in individuals we now define as having clinical obesity and not just having an elevated BMI. We also hope to have better allocation of our resources and treatments for individuals with clinical obesity rather than just an elevated BMI.

Melanie Cole, MS: Thank you so much, Dr. Kushner, for all the great work that you're doing and for joining us to explain it all. I hope you'll come back again as things progress and let us know what's going on. Thank you again. And to refer your patient or for more information, please visit our website at breakthroughsforphysicians.nm.org/endocrinology to get connected with one of our providers. That concludes this episode of Better Edge, a Northwestern Medicine podcast for physicians. I'm Melanie Cole.