Episode Transcript
[00:00:01] Intro: Welcome to Obesity a Disease, the official Obesity Medicine association podcast exploring the many facets of the disease of obesity A Disease podcast is brought to you by the Obesity Medicine Association, a clinical leader in obesity medicine.
[00:00:22] Christopher Weber: All right, welcome, everyone, to the Obesity Medicine Association's podcast, Obesity a Disease.
My name is Dr. Christopher Weber. I'm the bariatric services medical director at Ascension Wisconsin and the obesity medicine director at Ascension Columbia St. Mary's Bariatric Center. So this is a new industry insight series, which I'm very excited about. And I'll tell you, I'm especially excited about this topic today that we're going to get into talking about metabolism. But this series, I'll be interviewing leading industry experts on timely and important topics in obesity medicine.
So today we're joined by doctors Cameron Garber and Marc Humbert. They work with Core Medical Technologies, and we're going to be talking about resting metabolic rate. I tell you, like I said, I'm very excited about this one in particular.
People love talking about metabolism. I love talking about metabolism. I'll tell you clinically. I personally use core devices in my clinic. So, Marc, Cameron, welcome. Happy to have you here.
[00:01:22] Cameron Garber: That's our pleasure. Thank you for having us.
[00:01:25] Christopher Weber: All right, so to start off with, you know, people know metabolism is important somehow, but it's kind of vague in a lot of people's minds. I know clinicians, obesity medicine clinicians included, use calculations and estimates for figuring out resting metabolic rate.
But why should we care about it? Like, why should we measure it?
And are the calculations helpful? So talk me through the importance of this.
[00:01:52] Cameron Garber: Yeah, you know, it's kind of funny. A lot of our patients don't really understand fully what metabolism even is. You know, they ask funny questions like, do I even have a metabolism anymore? Is it fast? Is it slow? And things. And so measuring it really is important. We see it as a vital sign that it's. It's a vital sign like many other things. And I kind of think of it this way. If we did an intervention for somebody's blood pressure to. If they had high blood pressure, low blood pressure, we're going to measure their blood pressure frequently to ensure that the intervention that we're giving, whether it be lifestyle or medication or whatever, that it's having the desired effect. We're going to test blood pressure often.
Often the things that we're doing to treat obesity will have an effect on someone's metabolism. And yet we rarely measure that unless we have RMR testing in our clin.
And so that, I think, really does set the table for why aren't we measuring this and why is that so important like you asked? And it's because energy balance is really central to weight maintenance and obesity medicine.
Because the largest component of the calories that we burn every single day are our resting metabolic rate calories. So that's the cost of keeping the lights on in our body is, is that resting metabolic rate. And so we should probably measure that to know what is the cost for, for their individual body for keeping the lights on.
[00:03:23] Marc Humbert: Yeah, well, and I think to your question about the equations, they are, it can be great for tracking trends and putting you in the general ballpark, but they're based on population data, right. That Bell curve. And so even the best equations tend to be like 10% off. Many of them are like 30% off or more. And so while it might do a good job at looking at things on a population level, when we look at the individuals, there's a wide degree of variability. And so while even the best prediction equations have an average prediction error about 20 calories. Right. So they underestimate or overestimate calories compared to the, to the measured their limits of agreement. So the range that 95% of values are expected to fall in, even the best ones are like 450 calories. Right. So, so 200 plus or minus 200 on either side. Ish. And so that presents a problem. Right? Someone thinks that they are in a calorie deficit based on, on their predicted RMR and they may not in fact be. And so being able to dial that in with their measured data. Right. We're getting it directly from real time physiology. And so it's responsive to that person's metabolism. And I think that the thing that people get mixed up about sometimes is what does metabolism entail. Right. They're like, oh, it's just, it's my muscle and my fat, but it's, it's all of your tissues and, and muscle. Like while it's great to have like we want muscle, it's so important, we'll get into that later. Muscle is about 13 calories per kilogram. Fat's about four and a half.
Other tissues like our brain account for about 20% of our resting metabolic rate, even though it's about 2% of our weight. And so it has a much higher tissue specific metabolic rate. And so we see similar things in lungs and kidneys and heart that are very energy hungry. And so that's where a lot of the variability comes from, is just the difference in organ sizes, the difference in organ Specific metabolic rates. And so that's all captured with, with the breath data. Right. With what we can measure with indirect calorimetry. And so it just helps us to get much more specific to that individual. And so when we're looking at change over time, as Cameron mentioned, we want to see how the intervention is performing, then we want to make sure we're measuring what's actually happening so that we can see real trends over time.
[00:05:53] Cameron Garber: Yeah, and when we're measuring some, a specific individual, it becomes so much more precise. Then instead of being, you know, sometimes hundreds of calories off, we're able to be more specific to that individual and, and have really meaningful conversations based on that.
Because often we think exercise and movement and activity is where weight loss happens. And that's part of it. Exercise helps tune up the machine so that we burn calories more effectively and so that we can preserve our resting metabolic rate. But weight loss happens where we burn the most calories, which is in our resting metabolic rate. So if we suppress that too much, the number of calories that we can burn becomes so much less. And then our lifestyle and activity, that definitely plays a factor. But exercise really isn't where weight loss happens. That's just where the machine gets tuned up for burning calories everywhere else. But it's the everywhere else that weight loss actually happens, where that calorie deficit is created.
[00:06:53] Christopher Weber: Man, you guys are coming out of the gate with some great stuff here. I mean, this is so fascinating.
So I just want to respond to a few things that you said. One is, what is metabolism? Right? Boy, when I, when I talk with patients, they, they use that term to mean all sorts of different things, right? Like how much energy I have, am I tired, you know, how quickly I have to use the bathroom after I eat something.
So when someone asks you, hey, what is metabolism? How do you respond to that?
[00:07:19] Cameron Garber: So I like to explain it to people that, so they often people have heard of like anabolic steroids, right? And so I say anabolic means all the building up processes in our body, and catabolic means all of the breaking down processes in our body, like using things for energy, breaking apart calories for energy.
And so essentially, metabolism is the sum of all of the building up processes and that, that uses some energy as well, as well as the breaking down processes. So our anabolic and catabolic metabolisms together equal our metabolism. And so it's all of the processes that are happening inside of our body, that's our metabolism. And most of those things require energy to be able to do.
And so that whole sum of all the things that our body needs to take care of, that's our metabolism.
And so like we said, that resting metabolic rate is essentially what it costs to keep the lights on in terms of calories. This is how many calories we need just to keep hair and skin and nails and eyes and teeth and everything functioning properly, including internal organs, like Mark said, that are some of the most energy hungry parts of our body that we don't really consider that our heart has to keep beating all the time, so it uses a lot of energy.
And so that sum of all of those things, that's our metabolism. And so even if you have a slow metabolism, you still have a metabolism.
[00:08:49] Christopher Weber: Yeah, so. And that's exactly what I tell patients like, you know, this, we're talking about the, the resting metabolic rate and say it's, it's just to keep you alive.
[00:08:57] Marc Humbert: Right.
[00:08:58] Christopher Weber: So there's something there to fuel your heart to beat. And people just, just don't think about that. Right. How much energy. And everyone is always surprised how high, you know, wow, I burned that much just laying in bed all day.
[00:09:10] Cameron Garber: Yeah.
[00:09:12] Christopher Weber: So Marc, if, if your brain uses that many, you know, that much energy is like using your brain more. Does that help burn more calories?
Right. If you're like studying for a test or just think harder will that,
[00:09:25] Marc Humbert: you know, to, to a point, the more, more use our brain, probably not super substantial. You know, it's the, the brain again is the master governor. It's controlling everything that's going on in our body. And, and so there's a lot to coordinate. Even when we're doing nothing, even when we're not, quote, unquote, not thinking, there's still processing going on. You know, it has to govern what's happening with the heart and what's happening with the lungs, all those things that, that go on below our conscious awareness. Right.
Again, brain is the master regulator. And so regardless of what we're doing, it's going to be very energy hungry. Just because it has the systemic role.
[00:10:00] Cameron Garber: Yeah. But if you've noticed when you do high cognitive activities like studying or things, and you get hungry, you kind of get the munch.
That's part of that.
We also, when working with athletes, one of the interesting things. So aside from doing the resting metabolic testing, we also do exercise metabolic testing.
And it's really fascinating to try to help athletes calm their mind down so that they burn fewer calories during an event, so that, you know, the more they're overthinking something, the sooner they're going to bonk because they're actually burning that many more calories. So if we can help an athlete calm their mind better, they actually do better. In terms of endurance activities, that is
[00:10:42] Christopher Weber: so fascinating because we see people who are stressed out all the time and struggle with weight loss, so we always talk about stress. But that component's interesting.
And then just to highlight one thing that you said about the resting metabolic rate is, by and far, it's the bulk of where the energy is used. I see the picture behind you there with someone exercising. So I'm sure you guys are all. All four exercise, but absolutely. It's clearly a much smaller part when it comes to energy expenditure.
[00:11:13] Cameron Garber: Right, right. So if you imagine during a decent workout, you're burning four to maybe 600 calories. If you're. If you're pushing it pretty hard, that seems like a lot of calories that you burned from that workout. But if you think about it, if I just did an extra 30 to 50 calories an hour for the other 13 hours that I'm awake or whatever, or more, you know, 15 hours that I'm awake, you're gonna burn significantly more calories just in leading a more active lifestyle than you would during that one workout.
And so it's more about leading the active lifestyle. And again, exercise is so critically important.
It's what tunes up the machine. But it's. It's actually the active lifestyle on top of preserving that resting metabolic rate. That's where we're going to see the calorie deficit come from. So one of the things that we look at in our results pages with the metabolic testing, it prints out onto a form. With the review device, it prints out onto a form that has a balance. It looks like a scale where you can kind of see the calorie balance of calories in and calories out. And I love to look at that and say, okay, look, here's your exercise. You know, your estimated exercise calories, your lifestyle calories, and your resting metabolic rate. The resting metabolic rate is a huge chunk. The lifestyle and activity calories is a smaller chunk, but big. And the exercise is actually the smallest one. And so not that it's not important. It's just not where we're going to lose weight. So we got to stop thinking about it as, this is my punishment for what I ate last night, or I've got to burn off the calories for, you know, exercise is more about tuning up the machine so that everything else runs more efficiently and more effectively. The that we can preserve that resting metabolic rate even as we change body composition. And that, that really is the key.
[00:13:12] Marc Humbert: So, so one thing that I would add and, and I definitely want to come back to Cameron's point. Cause I love what he just said.
But there are some outlier cases right? As, as always there's, there's exceptions to the rule. And so typically exercise accounts for about 5% of energy expenditure. Actually what might be helpful really quick is to kind of look at what makes up energy expenditure. So as Cameron mentioned, your, your basal metabolic rate or resting metabolic rate makes up about 60 to 75% of your daily energy expenditure. About 20% of that is typically from NEAT your non exercise activity thermogenesis.
5% roughly is exercise and then 5 to 10% is TEF the thermic effect of food. So just the cost for your body to break down and liberate energy from the foods that you eat. And so again 5% ish commonly in exercise but in certain athlete populations that can go pretty high. Right. That can be 20% or higher of daily energy expenditure. And that's actually where we see certain issues in athletes where we get relative energy deficiency in sport where they're under eating in terms of calories and then they're kind of over exercising and their body just can't match that equation. And and so they start to have dysfunction in several systems, reproductive system, immune system, they may start losing muscle mass, increase in injuries like bone stress and things like that. And so you know there are always outliers, there's always extremes. And I think it's like the general case for most people especially they're looking to lose weight is exercise is not a huge proportion of that. Like Cameron mentioned, those lifestyle components are so much bigger. But, but I do want to bring attention to those extremes of exercise and some of the sequelae that can come from that.
[00:14:52] Cameron Garber: Yeah, yeah. And exercise is so important as part of helping people with obesity kind of stay on track and make long term progress improving their health.
You know, for every point of VO2 max we improve it's about a 9% reduction in all cause mortality.
And so helping somebody improve their fitness is going to make a huge difference in their, in their overall health risks. And, and that's really why we're trying to battle obesity is trying to decrease all of the, the different ways that, that they can die essentially. Right. All cause mortality. And so if we can improve their entire health profile that's really helpful. And one of the things with improving VO2max, that's really fascinating is that VO2max, the equation for VO2max.
When we sample those gases, it's milliliters of oxygen consumed per kg of body weight per minute just by helping somebody decrease body mass.
We often see an increase then in that VO2 max number just because the kilograms of body weight per minute are lower than they were before. And so we see fitness increases just from the weight loss alone.
[00:16:12] Christopher Weber: Yeah, I think this is critical, you know, hearing this story from exercise experts like yourselves. Right.
Because a lot of times I feel that patients may feel that we're underplaying exercise. I mean, as far as saying it's not super important for weight loss, kind of rationalizing or encouraging that word, you know, a lot of people don't like exercise. Yeah, it hurts. It hurts my heart when someone says, I exercise for three weeks. I didn't lose any weight, so I stopped. Like, no, that's not the point. So hearing that, you know, all of this from you guys is, is super helpful. Super helpful.
[00:16:47] Cameron Garber: Yeah, yeah. And, and I hear that in the clinic all the time. It's like, oh, I've tried a million times. And it's like, yeah, you tried several times for a short window, but never a consistently long enough to actually be able to tune up that, that calorie burning machine. So that's part of it is sticking with it long enough, but it's also realizing that it doesn't have to be as hard as what we think. It's more about consistency than intensity. And so I like to let people start out very, very light and build the habit first and then worry about the rest. And that seems to be more effective of like whatever you want to count as exercise. That's where we'll start and then we'll build from there. And so if it's a walk out to the mailbox to get going, as long as you consistently walk out to the mailbox once a day and then we start building that up, that's great. So again, because exercise isn't where we lose weight, but it can be a really helpful factor in helping us stay consistent in that weight loss and avoid plateaus and making our muscles more efficient at utilizing calories, at helping us be better able to switch between fuel sources, fats and carbohydrates, so that we avoid insulin resistance and all kinds of other things. So it's, it's not that it's not helpful, it's just not where we're going to see weight loss. So trying to burn off what you ate last night. And using exercise as a punishment for your, you know, poor food choices is not really what it should be about. It's more about feeling better. And, and so if you don't enjoy exercise, that's fine. It doesn't have to be like doing the boot camp class at the gym. It can just be, I'm going to walk as far as I feel like walking today and try to do that as consistently as possible until that becomes a little bit longer and a little bit longer as I feel better. And then it becomes more fun to do it because it's like, oh, I'm regaining independence in my life and lifestyle versus this is your punishment because you made all these bad choices.
[00:18:42] Marc Humbert: I think one thing to note too is that while exercise isn't always super effective in terms of weight loss, it does contribute.
When we look at the data sets for long term successful maintainers of weight loss, they almost all exclusively exercise. That's very well represented in the literature. And so it's an important ongoing habit to build. And to Cameron's point, you know, like, how do we make it enjoyable for people? One analogy I like to use is if you want to try a new type of food, you know, I'm going to try a new restaurant, going in and ordering the most like exotic thing and you, you know, you, you taste that like, oh, this, that was not for me, right?
And so it gives you, you know, an inaccurate perception of, of everything available within that type of restaurant, right? Within that type type of cuisine. And so I liken that to like, oh, I'm just going to go do hit style training, right? That's what I've heard camera mentioned the, the, the booty burn camps. And so we get a taste of exercise and, and it's very extreme, right? It's like the most exotic food that we've tried and we decide I don't like it, right? I haven't had my taste buds adapt at all to that type of cuisine. And so starting off simple, right? Like maybe it's, it's, you know, rice and beans I start off with and it's like, okay, you know what? I like this, this is, this is, this is great. I can do this, I can eat this consistently. And then we start to branch out and try different types of exercise. There are so many different modalities of exercise. And so there's certain principles in exercise that are important, right? We want that consistency, we want to have progressive overload. But the way that we actually implement that can be so variable. Um, and so just understanding that there's so many different flavors of exercise and we can mix and match those to find the, the, the types that work best for people that they can enjoy, that they can buy into. And as Cameron said, most importantly, they can be consistent with, because that's what matters the most over the long term. Like, consistency beats pretty much every, every other metric. You know, intensity, duration, all those things. Is, is this something that I can stick to for, you know, years, decades?
[00:20:46] Christopher Weber: Yeah, no, I love that analogy. That's. I, like, I'm going to use that one. I want to get back to measurements.
So we can measure resting metabolic rate. When should, when should clinicians do it?
[00:20:59] Cameron Garber: So I'm a big fan of starting with baselines, getting a good baseline measure. So, you know, at the beginning, this is where we're starting, so we can see what the adaptations are over time. Are we seeing changes happen? Are we seeing a rapid drop in, in that resting metabolic rate? Are we seeing that preserved? You know, typically with slow sustained weight loss, we see about a one to one ratio of body mass lost to resting metabolic rate decrease.
So it's, it's very common that we're going to see a decrease in resting metabolic rate with body mass loss because there's just less body to take care of. And so we would anticipate that. And that's very normal and natural part of losing weight.
But that's kind of what we want to see is that stays pretty close to the 1 to 1.
Whereas with more extreme weight loss, when we see using stimulants or extreme calorie restriction or other things, we'll often see and stimulants often, I think more than anything, just because of the extreme calorie deficit, we see a more like 4 to 1 or whatever that we see like a 5% loss in body mass and a 20% loss in metabolic rate.
And depending on how much weight that person has to lose, that sometimes can be okay if you've got somebody with a very, very high metabolism because they're quite obese. And so we're talking, you know, a resting metabolic rate of 3,500 calories a day.
We know that we can drop that significantly and still be at enough calories to maintain their body and proper functions. And that even as they lose weight, they probably will go even lower than that. So, you know, if they had went from 3500 down to 2500, that that could be okay as long as we make sure that's sustainable. But if you've Got somebody with a 1600 calorie resting metabolic rate and we're dropping down to 1200 now. We're making it very difficult for them to lead a normal, active, healthy lifestyle because the number of calories that they have to eat to, to not be in a calorie surplus now is so low that fueling their, their muscles and keeping the lights on and exercising and leading an active lifestyle becomes very challenging now at that point. And so they, they wind up feeling very lethargic and, and struggle to be able to participate in an active lifestyle. One, one of the things we always see or say is that, that RMR is a vital sign, and that's one of the ways that we use it as a vital sign is by tracking that resting metabolic rate number to see how that fluctuates as someone's losing weight so that we can keep that pretty consistent and make sure that we're not seeing too big of a drop in that resting metabolic rate as they're losing weight. Because that's the sign to me that then we're losing too much in the way of muscle mass.
We're not doing enough in terms of preserving muscle mass through protein intake and through consistent regular exercise.
[00:24:21] Christopher Weber: And Marc, maybe you can answer this one, but you said you want to monitor it also. So you have the baseline. You want to monitor it like you would with other vital signs.
How frequently do you monitor it?
[00:24:32] Cameron Garber: Great question.
[00:24:34] Marc Humbert: Yeah, it really depends. Often six to nine weeks is kind of a great amount of time to check in during a weight loss cycle.
And it's just, it helps you to kind of titrate the, the, the dose of, of calorie restriction. Um, if we're checking in and things are, are going well, right, they're losing like half a percent to a percent of, of body weight elite a week, kind of for the average person.
Then, you know, we're not seeing major slowdowns in metabolic rate, then great. But if we're seeing really big drops, um, if they're telling us things like, oh man, I, I just, with my exercises, I'm, I'm able to lift fewer and fewer weights during my strength training. Right. What are, what are signs pointing that we're tightening things up too fast? And as Cameron mentioned, this goes back to like, every, every individual is going to be different, right? Someone who has a lot of weight to lose is going to be very different from someone who has, you know, less weight to lose. And individuals are, are, have different rates. We'll call of metabolic adaptation. So some people, when they Begin to restrict calories, tighten up efficiency really fast. Right. So it only takes a small deficit to get them to start losing. Other people can, can kind of afford a loss of a lot of calories, a steeper deficit before their body really tightens down the hatches and starts to make modifications in resting metabolic rate. And so tracking that can help us to see the difference between those individuals. So they call it like thrifty or spendthrift metabolisms. And so it's basically like do I have a highly adaptive metabolism or a less adaptive metabolism?
And it's interesting because on the weight loss side, right, they might have to go into a steeper deficit, but also they can go into a larger calorie surplus typically before they begin adding weight on. And so just again, there is high variability individual to individual. And so regular measurement, especially through a weight loss journey, helps us to make sure that we are individualizing the interventions, the rates of everything to that person and helping them lose weight in a healthy and sustainable way.
[00:26:50] Cameron Garber: Yeah, and Marc, spot on with that. Like six to nine weeks is typically about the time that it takes to see much of a change in things. That's, that's actually a measurable change.
But sometimes that can vary just based on the frequent or the, the speed of weight loss. So how, how rapid that changes. So occasionally I will test more frequently if somebody's losing weight very rapidly or you know, if they're closer to their goal weight and more in a maintenance phase or nearing that and, and they're not making a change quite as rapidly, so we're were less likely to see a change in their metabolic rate, then you can usually move to more of a maintenance amount of, of quarterly or half yearly.
At that point I'm in a follow up to that.
[00:27:38] Christopher Weber: So that's kind of the timing of when you would do it. Are there any clinical situations where you do it, you know, someone's, I don't know, not feeling well or they've leveled off with their weight loss or any, anything kind of based on the patient's story that would prompt you to do it.
[00:27:53] Cameron Garber: Absolutely. So where from a reimbursement standpoint, if you're reimbursing this through insurance, there's not really much of a cap to that. So I haven't seen that be a thing where you, it's limited on how much you can do. It's basically seen as a lab. And so really if there is some kind of clinical mishap, whether it's a plateau, accelerated weight loss, all of a sudden, anytime you just have a question of like, what's really going on here. I think it would be a good time to retest because it's very simple and easy to do. It just takes a few minutes and, and it gives you just a really good snapshot kind of like blood pressure. If somebody's complaining about being dizzy and, and you know, the medication may not be working for them. You're going to test their blood pressure in, in a couple different positions and things to see what's going on. You kind of want to do the same thing with their metabolic rate where you're going to investigate what, what's the change to that metabolic rate so that we can see, get a better insight into what may be happening. And so anytime you see a fluctuation or a big question even I've had people where they got sick and were, were down for a couple of weeks, especially with COVID And so retesting after they come through a bout of prolonged illness can be a really helpful time because that may have really shifted that metabolic profile just from that prolonged sedentarism. And so you'll see a depression in their metabolic rate just because their, their muscles were, were not being used for a while. And so that can be really helpful at making sure that the calorie recommendations we're giving them are, are more on point for where their body's at right now.
[00:29:31] Marc Humbert: And one little thing I'd add onto that is any conditions that are affecting metabolism, metabolic rate can be interesting to look into with, with this type of data. So things like hypo or hyperthyroidism, diabetes can just be a useful metric to track as that person is getting treatment, just as another data set to look at to see like, hey, are things trending in the right direction or do we need to change some things up?
[00:29:57] Cameron Garber: Yep.
[00:29:59] Christopher Weber: Cameron, I just want to follow up on one thing that you just briefly mentioned there, because this is one of the most common questions I get in clinical practice is cost reimbursement, those sorts of things.
Talk about that.
[00:30:11] Cameron Garber: So, you know, Medicare fee schedule reimbursing for the test done on the review device, that RMR test is about 5350 or something like that, around $55 or so. For Medicare reimbursement, most of your private insurances are 75 to. I think the highest I've seen kind of one of the federal premium insurances is like 110, 120 and so most are right between like 70 and $85 private. If people are doing cash pay private it's usually 75 to about 150, just depending on what else is kind of packaged with that.
So private pay typically is a little bit more, but you are also not always, but often they're packaging that with kind of more services, more counseling and things. And so it's a little bit more of a premium service in some of those settings.
[00:31:07] Christopher Weber: So it is reimbursable.
[00:31:09] Cameron Garber: It is reimbursable. Yeah.
Yeah. I was talking to a provider in Idaho and he was saying that his average reimbursement is just over $80 and he gets reimbursed 90% of the time, which, you know, when I was doing insurance billing, I don't know that I ever got reimbursed 90% of the time for anything. So.
So it was a pretty good reimbursement rate for sure. So, yeah, it gets reimbursed pretty well through insurance. Most insurances accept that. It's because it is a great measure of being able to track things and it's usually something that's going to cost the insurance less money in the long run because you're helping that person get healthier.
[00:31:48] Christopher Weber: So yeah, good. So. So we've talked about what resting metabolic rate is, why to measure it, why it's important and when to do it. How about. And you guys touched on this a little bit as we've been going along here, but what do you do with the report? Is it going to change anything that, that we recommend for the patient?
[00:32:08] Cameron Garber: Yeah, I think for me it does a lot in terms of that calorie recommendation. How many calories should they be eating? It really helps me inform.
Are we over under reaching with exercise or other things?
One of the kind of a case example, I think of how it can help play into decision making.
I once had two women come in that were the same age, height, weight and gender and ethnicity.
On paper, you would think they should be about the same.
The predictive equation put them at about 1800 calories.
When we tested though, one came in at 1500 calorie RMR and the other at 2,300 calorie RMR.
Fascinating to see what I loved about this case example, and this is really what the data allows me to do more than anything is ask the right questions. I interviewed both of them afterward because I saw these numbers and the gap of variation from a predictive equation.
I interviewed them all about their life and lifestyle and what was going on and exercise habits, habits and all of those things.
And the one was quite sedentary. So the one who had the 1500 calorie RMR, quite sedentary, had already been through menopause, had yeah, just her life was very quiet. I guess she was an empty nester, all of these things.
The other lady, even though she was the same age, was still kind of at the tail end of menopause and was still had three children at home, was still running around, active and tried to exercise some days of the week. And so because of that she had a much higher metabolic rate just because of her activity level. If we had given the same exercise and calories prescription, we would have been under serving one and over serving the other in terms of, of that calorie recommendation if we were just using the averages and estimates. So it really allowed me to very specifically prescribe how many calories they should be eating and it helped inform our exercise habits as well.
And so really, really important to have that individualization because of that number. It allowed me to tailor that plan of care to each person very specifically.
[00:34:41] Marc Humbert: I think another nice thing it does is it puts us on the same side as the client because the data is just the data.
And so that can help us to again adjust the education that we're doing, adjust the type of interventions.
And I would say people are not lying about what they're doing. They just maybe lack insight into some of their behaviors. And I feel like this is a different situation.
So there's a famous study from 1992, it was a metabolic ward study where they tracked individuals energy expenditure and their food intake and people overestimated their energy expenditure by about 50%. They underestimated their food intake by about 50%. And so again this is not like I'm consciously doing this. It's just we're not aware of all the things that we do. Right. Like just throughout a common yesterday I'm getting dinner ready and like I, I have a couple peanuts and then like I take a little, you know, bite of this and a little bite of that and I'm eating little things while I'm making the meal. But when I think back to track it, I'm like oh yeah, here's what I had for the meal. And so there's things that we, that we miss or I think I'm more active than I, than I am. And so again just the data is what it is. And using that to have a conversation and saying like hey look, what are some things? What are you struggling with most? Like how can we help here? Or I've identified that this seems to be an issue.
Let's help you with that. And so it's just instead of this adversarial relationship that it sometimes feels like in weight loss, it's, hey, we're in this together, we're with you all the way, and let's use this data to help you to make those improvements, to make those lifestyle changes that will actually lead to not just long term weight loss, but long term improvement in health.
[00:36:22] Cameron Garber: Yeah, yeah. I love that concept of sitting on the same side of the table with your patient versus across the table. And that's what I think the data helps us do do is be able to be like, oh, you know, it looks like that resting metabolic rate is dropping faster than we'd like. How's it going with protein intake? Okay. You know, it's maybe not quite where we want it to be yet, but it's trending in the right direction. And so we can encourage them like, hey, good job on increasing your protein intake based on the numbers, it's still not quite enough. And so let's keep trending in that direction of finding ways to get more protein in. So instead of beating them over the head with it and being like, you're not doing enough, it allows us to be like, oh, the numbers are saying we're not quite there yet. And so let's, let's continue on that path of finding ways in your lifestyle to get more calories in. Because I think that's the key and one of the hardest parts when we're using nutritional guidelines and all of those things is understanding that this is a real person with a real life and real lifestyle. And we have to understand that it takes time to learn new behaviors and put new things into practice. That the way, you know, ultimately, if somebody really does go through this transformation of, from being obese to being at a healthy body weight, it changes fundamentally who they are at birthday parties, at barbecues, at how, how they show up at the grocery store, how they, you know, all these different aspects of their life and lifestyle eventually need to change to become that healthy, active person that they want to be and that we would love for them to be. And so having patience with that, of saying, yeah, these changes are going to have to happen over time.
By using this as a guideline and something that we can again sit on the same side of the table and encourage and help them with and be understanding in the fact that, yeah, some of these lifestyle changes are going to take some time that I really do think that helps to be able to track those numbers and use the numbers to show whether they're being successful with that or not, instead of just beating them over the head over and over again of like, oh, you're failing, and it just adds to that bucket. Or that. I call it the backpack of failure. We all carry around our backpack of all our past failures, and if we can help lighten that load so that they don't feel that so much, it really does help them be more successful. And using concrete numbers really does help them to know and for us to soften that blow of like, oh, okay, so it looks like you're improving here and here, but we still have some work to do here. And the numbers reflect that. And so let's keep working in that area.
[00:39:00] Christopher Weber: Yeah, I love it. Cameron, those are some great real world examples that highlight the importance of measuring. And then, Mark. Yeah, I agree that the data is. The data we're on the same side with the patient is fantastic. I tell you one thing that I see all the time that you just, you couldn't address unless you measure the resting metabolic rate is someone who says, I'm hardly eating anything, right. And my weight's not moving. And he's, you know, like you said, people underestimate. But also sometimes and often they're absolutely telling the truth. You do the test and like, wow, 1100 calories, that boy. I eat that before I roll out of bed in the morning. So I believe you're not eating much, but it's, it's more than your body needs. Right.
So having that data there can be extremely helpful.
[00:39:43] Cameron Garber: Yeah, yeah. It's really, it's tricky, especially, you know, with the advent of GLP1s and other things. Sometimes we see metabolic rates decrease so much because of extreme calorie restriction that then that becomes really difficult for somebody to eat fewer calories than that and not have some of the difficulties of muscle wasting and other things. I tested somebody the other day that was at about 700 calories. And I think, oh, man, if I walk. If you walk by a Starbucks, you absorb 700 calories. Right.
And so it becomes challenging for people in that way. And so sometimes we may need to pause the weight loss journey to focus more on, let's build up some muscle mass and build up that metabolic rate again for a period of time where we focus not on eating more calories in terms of weight gain, but in muscle gain. Right. And so we're not going to say, oh, go eat whatever, and let's ramp your metabolism back up. It's more very calculated in. We need to be eating enough to stimulate muscle growth. And development or at least muscle preservation. And so we may curb how much we're restricting calories for a period of time to allow for muscle building and ramping that resting metabolic rate up a little bit more and then we can calorie restrict again.
[00:41:06] Christopher Weber: Yeah, I can't believe we made it almost 40 minutes before GLP1s came up. That's about the longest.
[00:41:10] Cameron Garber: I know. Yeah, that's pretty crazy.
[00:41:13] Christopher Weber: So you kind of just touched on it here. But just to, to highlight it a little bit, we have a lot of people on GLP1s obviously who are, you know, losing a lot of weight. What's, what's the point of measuring, you know, resting metabolic rate if someone's doing well, they're on a GLP1. Any specific considerations we have to have for someone on a GLP1?
[00:41:34] Cameron Garber: Yeah, I personally feel like it's, it's every bit as critical if they're on a GLP1 because we want to make sure that we're setting that person up for long term success, that we're, they may be losing weight now, but are we driving that metabolic rate down so low that it becomes something that's not as sustainable in the long term? So if that's part of the plan, and we know that's going to happen somewhat, that we're going to drive that metabolic rate down because of the rapid weight loss, as long as we make sure that part of the plan and that the patient is bought in on that part of the plan, that we bring that metabolic rate up at the end and that we focus more on body recomposition and things like that as we're nearing our goal weight, that's a very critical thing. So it's, it's fine to some degree as long as we're part of the, that's part of the game plan. But what often happens is the patient loses the weight, they're happy and they leave and they haven't done the work to kind of build things back up and restore that metabolic rate to kind of a healthy, manageable level. And then they, they maybe become a little bit more lax on taking the drug. And the next thing you know, they, they lost 65 and they've put 70 back on and we see that all too frequently. And so as long as we're aware of the fact that it can drive that metabolic rate down and then we make sure to build it back up and so tracking that through the entire kind of plan of care for that patient and that we then maintain that afterward as well, that we continue to bring them in, test their metabolic rate and make sure that things are happening the way we would plan it to be, then I think we're fine. GLP1s have been nothing short of a miracle. It really has been amazing to see and I think we can really help a lot of people. But just making sure we're doing that in a smart way that is healthy for people in the long run. I always tell patients, as much as I want to help you lose weight now, or as much as I care about the now you, I actually care more about the 85 year old you.
And so anything that we do, I want it to be part of a long term plan that allows you to be that healthy, active 85 year old that can put their luggage in the overhead bin as they're going on a vacation because they're able to enjoy life for the duration of their life. And so if what we're doing doesn't lead towards sustainability, then I think maybe it's a little bit too extreme for us to really help in the short term and the long term. And so let's focus on what's a sustainable amount of weight loss. And so in the obesity population, obviously, especially if people are morbidly obese, just getting the weight off initially is going to be one of the most important factors. But as we near more of their goal weight or more of a sustainable, healthy body mass, then we need to really take into consideration some of those things that we're helping them think more, you know, transition more into life and lifestyle and how we can sustain these results.
[00:44:39] Marc Humbert: Yeah, and I would add just the importance of maintaining muscle mass. Again, if we're seeing, with RMR testing, if we're seeing really big drops in metabolic rate, then that can be one indicator that we're wasting muscle faster than we want. And you know, think if we can talk about what's the quality of that weight loss with people, right? Like, do you want to lose 30 pounds? You know, you say you want to lose 30 pounds, do you want to lose 30 pounds of muscle?
Well, no, I'd like to lose 30 pounds of fat. It's like, okay, well some things are going to have to change if we want the quality of that weight loss to be different.
You know, in general, it's kind of assumed a fourth of the weight loss is going to be from, from lean mass, of which a proportion of that lean mass is muscle mass. But that doesn't necessarily have to be the case.
And so we're seeing with more recent research that People that are eating sufficient protein, so somewhere between like 1.6 grams per kg and 2.2 grams per kg, there seems to be kind of a break point at that 1.6. And then are doing regular resistance training, so at least two to three times a week can actually preserve that muscle mass and in some cases actually gain muscle mass. So they have that true body recomposition. They're losing fat while they're gaining muscle. There was a recent case series by Tinsley and Nadolski that tracked a few patients that looked at that and showing that there was in fact some lean mass gain during a dieting period. And so again, if we're seeing those really rapid drops in RMR and then we might be muscle wasting and that has just so many implications. You know, muscle again is a, is a master metabolic regulator. It's a great glucose sink.
But also we see past the age of 65, injuries from falls go up exponentially.
Metabolic rate in general, when we look at metabolic rate across lifetime. So Herman Poncer and colleagues came out with a really good study recently that looked at metabolism across the lifespan. And, and what we found is that metabolism actually stays remarkably similar from ages 20 to 60 and that most of the drops in metabolism after the age of 60 are actually in fact due to lean muscle mass loss. And so it becomes importantly, incredibly important at every stage of the life span, but especially as we get older to preserve muscle mass because of all of its implications for long term health.
Injury, avoiding injury, being able to recover, you know, regulating our metabolism.
Because the question is like, not if I have an illness or injury, it's like, when is that going to happen and do I have a big enough reserve to draw from when that happens? And so probably the physical therapy background, right, Importance of exercise and muscle, but I find that that's an actual, absolutely crucial thing to understand. And, and I think there's, with GLP1 specifically, you know, there, there's worry about muscle mass lost, but it's similar on any calorie restriction thing, right? Whether you do bariatric surgery or just calorie restriction, it's just because it's such an effective appetite suppressant. Often people just lose their interest in food and drop weight very quickly. And so when that's happening, losing muscle mass can be a major concern. And so making sure that we're getting enough protein and making sure that we're getting regular resistance training in and then tracking those changes with repeated RMR testing can just help us make sure that it's, it's more of the quality weight loss that we want. Right. That's more fat mass, less muscle mass, and that it's, as Cameron mentioned, sustainable.
[00:48:12] Cameron Garber: Yeah. And I think that's so important to note that it's not the GLP1 drug itself that is reducing muscle mass or bone density or things like that. It's the calorie restriction that's causing that. And it's just the appetite suppression from the GLP1 that, that allows that to happen. But it's the drug itself is. Is not causing that. It's just that we're not fueling, especially not getting enough protein to be able to have the building blocks to sustain muscle growth and development. We talked earlier about anabolic and catabolic pathways. And our muscles are constantly being kind of broken down and built back up and broken down and built back up. And the way we use those muscles is then what triggers do we build it up stronger or do we build it up weaker because we're not using it? And so when we have extreme calorie restriction in those cycles of building up and breaking down, it just says, well, I don't have enough building blocks to build it back up. And so we waste away muscle very rapidly when we're feeling very low energy because of calorie restriction on top of. So the sedentarism on top of just not having the building blocks, we lose muscle mass very quickly.
[00:49:23] Christopher Weber: No, I mean, super important points. And for our listeners, I recommend reading that study by Ponzer. It's.
It's super interesting. And, you know, I see a lot of people who, as they get older, they say, I'm doomed. You know, I can't lose weight because I'm getting older. Right. And this is another piece of evidence that says, no, hold on, we can do something about this.
[00:49:42] Cameron Garber: Right? Yeah. Yeah.
[00:49:43] Christopher Weber: So we wrap up with one more. One more question here for you guys. So the reason we're doing this series is one, we like talking to you guys and you're experts in the field, so I like learning things here. But it's for our audience too, and the clinicians to improve patient care and patient outcomes. So, you know, hopefully, and I suspect the answer is yes, that our clinicians will make a change in what they're doing. So if you had to pick, you know, the most important thing that you want clinicians to take away from this, to improve patient outcomes and how they practice, what, what would you tell them?
[00:50:16] Cameron Garber: Hmm, Great question.
I think the biggest take home for me, or the biggest point of emphasis was be it's hard to adjust something that you don't know what the numbers are behind it. And so by tracking that, it allows you to just make a more specific exercise prescription for that person's life and lifestyle.
And so by having the right numbers, we can ask the right questions that then lead us to the right solution for that person. Because we like to just, you know, say it's all about calories in and calories out. And it unfortunately isn't quite that simple because it's calories in, calories out within the framework of somebody's life and lifestyle. And how can we help them actually do that? So for me, that's the point of using these numbers to ask the right questions that are then going to help us individualize that care. We, we talk a lot about, you know, that specificity of care and, and you know, very targeted medicine for that person.
This, this to me is the pinnacle of that of being able to, you know, give very specific plan of care for that person.
[00:51:27] Christopher Weber: And what struck me that you said earlier on this topic was comparing it to blood pressure. Can you imagine if we did a, a calculation to figure out what someone's blood pressure should be on average and we didn't measure it?
[00:51:38] Cameron Garber: Right.
[00:51:38] Christopher Weber: No. That's great. And how about you, Marc? What do you think?
[00:51:42] Marc Humbert: Yeah, I think again, I'm such a fan of RMR testing.
At the end of the day, it's one tool among some really good ones. And so understanding that there's not just one thing that's going to be the magic bullet for weight loss, it's a combination of different tools and being able to take the time with patients to individualize it to them.
I think we can't separate physiology from psychology and I think sometimes we try to and that becomes really ineffective in terms of weight loss because we're dealing with real humans with real lives with real constraints. And so being able to use the tools that can help with measurement, but then also can help with behavior change and combining those to create really robust effects in terms of long term weight loss and management. Because if we just try to use the tool divorced from understanding what people are going through and like Cameron mentioned, using the tools to ask questions and get a deeper insight into what's happening in people's lives so that we can take all that data to put it together and create a plan for successful short term and long term change.
And so just it's this coordinated effort of different tools and different health professionals. Right. I think so often we get siloed in our own specialties. But it's using all the data that we have, using all the tools that we have, working together as a team, as a healthcare hub so that we can help people through the process of not just physiological change, but long term behavior change that, that results in better moments with people. One of the things that Cameron and I say is metrics are important, but moments are what matter. Can I, you know, do you get to walk your daughter down the aisle? Do you get to travel the world like you want? Do you get to play with your grandkids and be involved in their lives and activities? It's using these tools to create moments in patients lives.
[00:53:49] Christopher Weber: Man, I love that cross disciplinary approach. Right, so we have a physical therapist talking about behavioral health with the focus on patient quality of life. That is fantastic.
I love it. All right, so Marc and Cameron, great to talk to you. You know, as, as I predicted and hope this, this was a fantastic conversation. I learned a lot. I'm sure our audience did also.
Really thank you for sharing your insights and thank you to our listeners also for, for joining us on this industry insights episode of obesity, a disease. We look forward to having you with us again soon.
[00:54:20] Christopher Weber: Thanks again Marc and Cameron, appreciate it.
[00:54:22] Marc Humbert: Thank you.
[00:54:23] Cameron Garber: Thank you.
