How to Prevent Muscle Loss While Taking Weight Loss Drugs
Reading Time: 7 minutes, 31 seconds
BY: ISSA
DATE: 2024-04-21
Ozempic. Wegovy. Mounjaro.
Medications like these are rewriting the rules of weight loss - helping people drop pounds faster than ever before. But there's a hidden cost to the number going down on the scale: you might be losing muscle mass, not just fat.
That's a problem. Muscle isn't just about looking toned, it's your engine for mobility, metabolism, and long-term health. And if you're on GLP-1 medications (like semaglutide) or supporting someone who is, understanding how to eat and train to protect lean muscle mass is mission-critical.
Weight loss drugs work in a variety of ways. Some lower body weight by increasing the excretion of glucose in the urine. These are referred to as sodium-glucose co-transporter 2 (SGLT2) inhibitors. Invokana, Farixga, and Jardiance all fall into this category. Though they’ve not been approved for weight loss, they are sometimes prescribed for this purpose.
Other medications assist with fat loss by reducing appetite. This makes it easier for people to follow a low-calorie diet. Weight loss drugs known as glucagon-like peptide-1 (GLP-1) receptor agonists fall into this category. Wegovy and Ozempic are both GLP-1 RA medications.
Research indicates that prescriptions for SGLT2 and GLP-1 drugs have increased by 114.6% and 221% respectively. (1) While access to a prescription weight loss medication can help people lower their body weight, many users also face muscle loss.
Connection Between Weight Loss Medication and Muscle Loss
To be fair, lean mass loss isn’t a direct effect of these drugs. Put another way, the drug itself doesn’t “eat” lean muscle, causing it to go away. Instead, the effect is often a result of rapid weight loss.
When a person consumes drastically fewer calories than they’re used to, the body looks for other sources of fuel. Unfortunately, it can choose muscle as its fuel source. Research confirms this.
In a 2021 study, 1,961 adults with obesity took either semaglutide or a placebo. (Semaglutide is the active drug in Wegovy.) After 68 weeks, the mean weight loss in subjects taking the active ingredient was 14.9% of their original body weight compared to a 2.4% loss in the group taking the placebo or sham drug. (2)
If you look at the supplementary appendix for this study, it breaks down these losses. The sham group only lost 0.19% of their fat mass while the semaglutide group lost 10.4% of their fat. But they also had less muscle loss as well. Specifically, those taking the placebo lost roughly 0.11% of their lean mass, of which muscle mass is a part. Those taking semaglutide lost much more or approximately 3.61% of their lean mass. (3)
This discrepancy in muscle mass loss is due, in part, to the semaglutide group achieving a higher level of weight loss. In short, the more weight you lose, the more muscle you risk losing too, especially if you're not strength training or consuming enough protein.
Consequences of Losing Muscle
Generally speaking, losing weight is good—especially for people with obesity. Obesity can increase one’s risk of heart disease, type 2 diabetes, and musculoskeletal issues. It can even lead to poorer mental health.
One study found that children with obesity have a 7.15 times greater risk of having a mental health disorder in their teenage years than children with a normal weight. (4) Anxiety and mood disorders are a common concern. So too is attention-deficit hyperactivity disorder (ADHD). That said, with weight loss, there are also consequences of losing muscle mass.
When you lose muscle, everyday activities can be harder to perform. You might struggle to open a jar, for example. Or you may find it more difficult to push the mower around the yard.
A certain amount of muscle wasting or loss is common with age. This is referred to as sarcopenia. If too much muscle is lost, it can affect the older person’s level of independence. It can also increase their frailty according to the Cleveland Clinic. (5) This raises their risk of falls and fractures.
Losing too much muscle at a younger age can have the same effect. That’s why it’s important to find ways to protect muscle mass when on weight loss drugs. How can you do this?
How to Prevent Muscle Loss While Taking Weight Loss Drugs
Ask any personal trainer how to build muscle and they’ll likely give you two pieces of advice. They’ll tell you to eat more protein and to engage in resistance training. So, it only makes sense that these same strategies can also help protect against the loss of muscle mass.
Eat More Protein
Protein is the building block of muscle, which is why it's important to understand how to get enough protein on semaglutide to help preserve lean mass during weight loss. The body uses amino acids for both muscle growth and repair. Research has found that eating more of your calories in the form of protein helps prevent muscle loss. (6) And this approach appears to offer the greatest impact when protein intake is distributed evenly across one’s meals.
Animal-based foods are often high in protein. This includes lean meats, eggs, and dairy products. Those following a plant-based diet can also increase the protein in their diet by eating more nuts, seeds, and beans. Tofu is another good plant-based protein source, as are soy and grains. Eating more of these foods can provide the body with the nutrients it needs to maintain muscle mass.
The recommended protein intake for the average person is generally between 0.7 and 0.9 grams per kilogram of body weight per day. However, some need more, such as those with higher levels of physical activity. A dietitian or nutritionist can help determine the best amount to consume based on a person’s situation and needs.
Add Strength Training Into Your Exercise Routine
Another way to protect lean mass when taking weight loss drugs is with resistance training. Resistance training promotes muscle growth. It makes muscle bigger and stronger. This helps combat muscle mass loss.
Gaining muscle provides another positive effect for people interested in losing weight. It increases calories burned. The body requires more energy to maintain muscle than fat, which means greater fat burn all day long. This makes weight loss easier by contributing to a higher calorie deficit. This leads to a reduction in body fat.
There are numerous ways to structure a strength training workout. You can do full-body workouts, hitting every muscle group in the same session. Or you can do more of a split schedule, working one muscle group one day and a different one the next. Both approaches can help protect and grow muscle mass. Aim to work on each muscle group 2-3 times per week.
Combine Nutrition and Exercise for Long-Term Results
A weight loss drug is a tool available for people interested in losing weight. But it isn’t necessarily designed to be the only tool used. The Obesity Medicine Association reports that this type of drug is “most effective when they are used as part of a comprehensive treatment plan.” (7) In short, diet and exercise are also important.
Eating healthy foods and getting regular exercise helps protect lean body mass while contributing to weight loss. They’re also critical for weight management. If you achieve weight loss with only medication, you haven’t developed the habits necessary to sustain that loss. You may even set yourself up for weight gain when stopping the drug.
Working with a personal trainer and nutritionist can go a long way in supporting lasting weight loss. These professionals can teach you how to develop lifelong habits for better body composition. You can also learn both aspects of the fitness industry through certification courses, enabling you to help yourself and others achieve and maintain effective weight loss.
Frequently Asked Questions About Weight Loss Medications and Muscle Loss
Do weight loss drugs actually cause muscle loss?
Not directly. The medication itself isn't "eating" your muscle, but when you lose weight quickly (especially without enough protein or strength training), your body might break down muscle along with fat. It's more about how you lose weight than the medication itself.
Why does losing muscle matter if I'm still losing weight?
Because muscle keeps you strong, independent, and more active. It also helps burn calories, even at rest. Losing too much muscle can make everyday tasks harder and may slow your metabolism, making it tougher to keep the weight off long-term.
How much protein should I eat to hold onto muscle?
Most people do well with around 0.7 to 0.9 grams of protein per kilogram of body weight each day. But if you're exercising regularly or losing weight, you might need more. A dietician or nutrition coach can help you determine what is right for your goals.
Can strength training really make a difference?
Yes, 100%. Strength training is one of the best things you can do to protect (and even build) muscle while losing weight. It also helps keep you strong, improves your posture and can make everyday movement feel easier.
Do I still need to focus on my diet if I'm taking a GLP-1?
Definitely. GLP-1 medications are tools, not magic. A healthy, balanced diet (especially one that includes enough protein) gives your body what it needs to stay strong and support long-term results. The goal isn't just weight loss, it's better overall health.
Help Clients Lose Weight the Healthy Way with Dual Certification
If you want to go deeper, ISSA offers certifications in both Personal Training and Nutrition - so you can build a complete understanding of how to protect muscle, support healthy weight loss and help others do the same.
Want to learn how to support your clients (or yourself) though healthy, sustainable weight loss? Contact an ISSA Fitness Education Advisor and enroll today to become an ISSA Certified Personal Trainer and Nutrition Coach. Simply call 1-800-892-4772.
References
Dzaye, O., Berning, P., Razavi, A. C., Adhikari, R., Jha, K., Nasir, K., Ayers, J. W., Mortensen, M. B., & Blaha, M. J. (2022). Online searches for SGLT-2 inhibitors and GLP-1 receptor agonists correlate with prescription rates in the United States: An infodemiological study. Frontiers in Cardiovascular Medicine, 9. https://doi.org/10.3389/fcvm.2022.936651
Wilding, J., Batterham, R. L., Calanna, S., Davies, M. J., Van Gaal, L. F., Lingvay, I., McGowan, B., Rosenstock, J., Tran, M. T. D., Wadden, T. A., Wharton, S., Yokote, K., Zeuthen, N., & Kushner, R. F. (2021). Once-Weekly Semaglutide in Adults with Overweight or Obesity. The New England Journal of Medicine, 384(11), 989–1002. https://doi.org/10.1056/nejmoa2032183
Wilding, J., Batterham, R. L., Calanna, S., Davies, M. J., Van Gaal, L. F., Lingvay, I., McGowan, B., Rosenstock, J., Tran, M. T. D., Wadden, T. A., Wharton, S., Yokote, K., Zeuthen, N., & Kushner, R. F. (2021c). Once-Weekly Semaglutide in Adults with Overweight or Obesity - Supplementary Appendix. The New England Journal of Medicine, 384(11), 989–1002. https://doi.org/10.1056/nejmoa2032183
Beltrán‐Garrayo, L., Solar, M., Blanco, M., Berna, M. G., & Sepúlveda, A. R. (2023). Examining associations between obesity and mental health disorders from childhood to adolescence: A case-control prospective study. Psychiatry Research, 326, 115296. https://doi.org/10.1016/j.psychres.2023.115296
Professional, C. C. M. (n.d.). Sarcopenia. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/23167-sarcopenia
Carbone, J. W., & Pasiakos, S. M. (2019). Dietary Protein and Muscle Mass: Translating science to application and health benefit. Nutrients, 11(5), 1136. https://doi.org/10.3390/nu11051136
Obesity Medicine Association. (2024, January 29). Top weight loss medications. Obesity Medicine Association. https://obesitymedicine.org/blog/weight-loss-medications/