QD Clinic: Managing Muscle and Fat Loss with GLP-1s Save
Dr. David Liew, Melbourne, presents this QD Clinic as part of RheumNow's "The Obesity Imperative" campaign presented in September 2026.
Transcription
David Lou here for RheumNow. This is my QD clinic about what to talk about in terms of muscle mass and fat mass with GLP-1 receptor agonists. So I think this must happen to everyone who listens. You get approached by one of your patients and this seems to happen to me on a you know day-to-day basis. Patient wants to take a GLP-1 receptor agonist. Doctor, is there anything I should be worried about or anything? Is that okay if I go ahead? Firstly, thank you for asking me. But what am I thinking about in terms of giving proactive advice?
And so naturally I think about the patients that now you think about maybe 3 or 4 years ago started a GLP-1 receptor agonist and then lost weight and then stopped it a lot of the time and then put weight back on. How their journey has gone and maybe what we could have done better or worse. I think about the patients who have kind of gone through that process and have managed to lose substantive amounts of weight. And anytime you lose substantive amounts of weight, you risk not just losing fat, but you lose muscle as well. Maybe not quite as much as fat, but you certainly lose muscle. And that's something that's been borne out in the GLP-1 receptor agonist registration studies. We've seen that especially in semaglutide studies and tirzepatide studies. And it's not to say that there's not more fat loss than muscle loss, but you can't inherently miss out on losing muscle mass in that process.
The problem is at that point where you stop the medicine and if you put mass back on, which we know happens in the context of stopping, that's been well proven, that actually we see that you put on disproportionately more fat than muscle, especially early on. Now, this is not something that you see in lifestyle-based weight loss. It's more progressive and you seem to be able to maintain muscle mass more.
And the reason why I talk about this is because it's fundamentally important to a lot of the biomechanical issues that we deal with with our patients in clinic. If it's going to drive joint pain and joint function, muscular pain and muscular function, then we really got to try and address this proactively.
So what can we do about this? Well, basically trying to think about what we can do proactively to give that advice about muscle mass retention is what I wish I'd given my patients 4 years ago. We obviously know more now, but isometric strengthening with appropriate amounts of protein intake, I think, are really the key. And there's reasonably good evidence for isometric strengthening in the context of retaining muscle mass. We know how important that is in our patients in general. But in this situation where you're about to really test the body in terms of how it goes with retaining that muscle, it seems all the more important to be proactive about this.
Now, I think there are lots of ways about going through this and physical therapy can be really useful and that kind of upfront education, but of course there are some really good websites as well. I just want to make a plug for two Australian websites: mykneeexercise.org.au and myhipexercise.org.au, which are free websites with actual exercise plans to really go about and grade up in that case knee and hip muscle strength. We know that the AAOS, the orthopedic surgeons, and the Arthritis Foundation also have some really good resources online about how to maintain some of this muscle strength.
And we don't need to go overboard with the protein either, but we certainly need to have enough to be able to fuel that muscle maintenance. Sometimes there's a bit of talk about ketogenic diets and whether they're superior in this context. And the data for that is actually limited. There's a little bit of poor quality evidence about it, but really I think getting too far into the unsustainable details is probably not what we're looking to do for our patients. What we're looking to do is kind of give some really solid achievable advice. That is: when you start the GLP-1 receptor agonist, not later, but when you start, make sure that you maintain a little bit of protein intake, but most importantly, do those isometric strengthening exercises.
For plenty more on this obesity campaign and all the fantastic content, you know where to go. RheumNow.com.
And so naturally I think about the patients that now you think about maybe 3 or 4 years ago started a GLP-1 receptor agonist and then lost weight and then stopped it a lot of the time and then put weight back on. How their journey has gone and maybe what we could have done better or worse. I think about the patients who have kind of gone through that process and have managed to lose substantive amounts of weight. And anytime you lose substantive amounts of weight, you risk not just losing fat, but you lose muscle as well. Maybe not quite as much as fat, but you certainly lose muscle. And that's something that's been borne out in the GLP-1 receptor agonist registration studies. We've seen that especially in semaglutide studies and tirzepatide studies. And it's not to say that there's not more fat loss than muscle loss, but you can't inherently miss out on losing muscle mass in that process.
The problem is at that point where you stop the medicine and if you put mass back on, which we know happens in the context of stopping, that's been well proven, that actually we see that you put on disproportionately more fat than muscle, especially early on. Now, this is not something that you see in lifestyle-based weight loss. It's more progressive and you seem to be able to maintain muscle mass more.
And the reason why I talk about this is because it's fundamentally important to a lot of the biomechanical issues that we deal with with our patients in clinic. If it's going to drive joint pain and joint function, muscular pain and muscular function, then we really got to try and address this proactively.
So what can we do about this? Well, basically trying to think about what we can do proactively to give that advice about muscle mass retention is what I wish I'd given my patients 4 years ago. We obviously know more now, but isometric strengthening with appropriate amounts of protein intake, I think, are really the key. And there's reasonably good evidence for isometric strengthening in the context of retaining muscle mass. We know how important that is in our patients in general. But in this situation where you're about to really test the body in terms of how it goes with retaining that muscle, it seems all the more important to be proactive about this.
Now, I think there are lots of ways about going through this and physical therapy can be really useful and that kind of upfront education, but of course there are some really good websites as well. I just want to make a plug for two Australian websites: mykneeexercise.org.au and myhipexercise.org.au, which are free websites with actual exercise plans to really go about and grade up in that case knee and hip muscle strength. We know that the AAOS, the orthopedic surgeons, and the Arthritis Foundation also have some really good resources online about how to maintain some of this muscle strength.
And we don't need to go overboard with the protein either, but we certainly need to have enough to be able to fuel that muscle maintenance. Sometimes there's a bit of talk about ketogenic diets and whether they're superior in this context. And the data for that is actually limited. There's a little bit of poor quality evidence about it, but really I think getting too far into the unsustainable details is probably not what we're looking to do for our patients. What we're looking to do is kind of give some really solid achievable advice. That is: when you start the GLP-1 receptor agonist, not later, but when you start, make sure that you maintain a little bit of protein intake, but most importantly, do those isometric strengthening exercises.
For plenty more on this obesity campaign and all the fantastic content, you know where to go. RheumNow.com.
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