GLP-1 Weight Loss: What Are You Actually Losing?
If you’ve spent any time online lately, you’ve probably noticed that it seems like everyone is talking about GLP-1 medications. Some people think they’re a miracle, while others think using them is cheating. And if you’ve read enough opinions, you’re probably more confused than when you started.
At Marino’s Fitness, we’ve had the opportunity to work with several members taking GLP-1 medications. They’ve had tremendous success losing weight, and we’re genuinely excited for them.
However, we were paying even closer attention to the weight they weren’t losing: their muscle.
Why?
When most people say they want to lose weight, what they really mean is they want to lose body fat.
The problem is, your body doesn’t always know the difference.
Whenever you lose weight, whether it’s through diet, increased activity, or a GLP-1 medication, your body typically loses a combination of fat and muscle. The goal isn’t simply to lose weight. The goal is to lose as much fat as possible while holding onto as much muscle as you can.
That distinction matters more than most people realize.
Expert Perspective
Melissa Bradley, CRNP, Director of Clinical Quality at Christine Meyer, MD and Associates, sees that distinction as an important part of the GLP-1 conversation:
“As a nurse practitioner in internal medicine with a degree in sports medicine, I emphasize that there is no such thing as a magic weight loss medication. GLP-1 therapies can be a valuable tool, but they are most effective when combined with consistent lifestyle efforts that support long-term health. The goal is not simply weight loss, but preserving a body that is strong, functional, and capable of lifelong activity. Prioritizing strength, mobility, and muscle maintenance helps ensure people can continue doing the activities they enjoy, from hiking and running to playing with children and grandchildren. The definition of health is about far more than the number on the scale!”
Melissa Bradley, CRNP, Director of Clinical Quality at Christine Meyer, MD and Associates
Muscle plays a role in almost every aspect of your health.
It contributes significantly to your resting metabolic rate, meaning it helps determine how many calories your body burns throughout the day, even when you’re resting.
It’s one of the primary places your body stores and uses glucose, making it incredibly important for healthy blood sugar regulation.
It allows you to stay active, recover from injuries, maintain your balance, and continue doing the hobbies you love.
As you get older, muscle often becomes the difference between needing help and maintaining your independence.
In other words, muscle isn’t just something you build in the gym.
It’s something you rely on every single day.
The challenge is that we’re already losing muscle as we age
One of the realities of getting older is that we naturally begin to lose muscle over time.
If nothing changes, that loss gradually adds up year after year. It can eventually affect strength, mobility, balance, and overall quality of life.
For many people, strength training becomes less about looking better and more about preserving the abilities they want to keep for decades to come.
That’s one of the reasons we believe resistance training is one of the best investments you can make in your future health.
Where GLP-1 medications fit into the picture
GLP-1 medications have helped many people lose weight who struggled for years to do so.
For the right person, under the guidance of their healthcare provider, they can be an incredibly effective tool.
But like any significant weight loss, there is something to pay attention to.
Because these medications often lead to rapid weight loss, there is a risk of losing muscle along with body fat if steps aren’t taken to protect it.
Muscle loss isn’t inevitable. You have the power to protect it. Muscle preservation needs to become part of the plan.
Who should pay the closest attention?
Preserving muscle is important for everyone, but it’s especially important if you fall into one of these groups:
Older adults who are already experiencing age-related muscle loss.
People who begin their weight loss journey with relatively low muscle mass.
Individuals who aren’t regularly strength training.
Women in perimenopause and postmenopause, when hormonal changes can make maintaining muscle more challenging.
For these individuals, protecting muscle isn’t just about improving body composition. It’s about protecting long-term health and quality of life.
What we’ve seen firsthand
This is exactly why we’ve been so encouraged by the members we’ve worked with using GLP-1 medications.
They didn’t just lose weight.
They maintained their muscle mass throughout the process.
That wasn’t luck.
They consistently strength trained, prioritized protein, and monitored more than just the number on the scale. By tracking body composition, we were able to see what was actually changing inside their bodies, not just what the scale happened to say that day.
To us, that’s the real success story.
Because nutrition plays such an important role in preserving muscle during weight loss, we asked Jennifer Barr, a registered dietitian at Downingtown Nutrition and one of our trusted partners, what she focuses on with patients using GLP-1 medications.
“Muscle breakdown or sarcopenia can be minimized with a high-protein diet and consistent strength training. Monitoring body fat and muscle with a tool such as InBody is also essential for success.”
Jennifer Barr, MPH, CDCES, RDN, Owner of Downingtown Nutrition
If your goal is to lose body fat, here are your priorities
Whether you’re taking a GLP-1 medication or not, the fundamentals don’t change. If your goal is to lose body fat while preserving as much muscle as possible, these should be your top priorities:
1. Eat enough protein
Protein provides your body with the building blocks it needs to maintain muscle while you’re in a calorie deficit. If you’re eating less, every bite becomes more important. Prioritizing protein at each meal can go a long way toward protecting the muscle you’ve worked hard to build.
2. Strength train consistently
Your body adapts to the demands you place on it. Strength training tells your body that your muscle is still needed, giving it a reason to hold onto it during weight loss. You don’t have to become a powerlifter. You just need a well-designed program that challenges your muscles on a regular basis.
3. Track more than just your weight, schedule regular Inbody tests
The scale can tell you how much weight you’ve lost, but it can’t tell you what you’ve lost. That’s why we use InBody assessments. They allow us to track changes in body fat and skeletal muscle over time, helping ensure that your weight loss is moving in the right direction.
The takeaway
If you’re taking a GLP-1 medication, don’t let the scale be your only measure of progress.
Losing weight can absolutely improve your health.
But preserving the muscle that supports your metabolism, helps regulate blood sugar, keeps you strong, and allows you to stay independent is just as important.
At Marino’s Fitness, our goal has never been to help people simply weigh less.
Our goal is to help people become healthier and live better.