Preserving Lean Muscle Mass While on GLP-1 Receptor Agonist Therapy

Introduction

As a physician, one of my primary goals is to ensure that my patients achieve optimal health outcomes while minimizing potential side effects of their treatments. GLP-1 (glucagon-like peptide) receptor agonists, such as semaglutide and liraglutide, are effective medications for managing type 2 diabetes and obesity. They work by enhancing insulin secretion, slowing gastric emptying, and reducing appetite, which helps in weight loss. However, an important concern with any weight loss regimen is the preservation of lean muscle mass. 

You may have heard that these medications are great at helping us lose weight. But you may have also heard that not all of the weight that we are losing with these medications is just fat loss. Studies have shown that lean tissue mass is also declining. Depending on the study, this loss appears to be anywhere between 0-40%. Although that loss is concerning, it’s also not unique to this class of medications. The loss of lean mass happens with any caloric-restricted weight loss. You could even make the argument that since the majority of weight loss is still from fat, we are actually improving the overall ratio of lean mass/fat mass in the body, even with using these medications.  

 However, the preservation of lean mass is crucially important to our health. In fact, it’s so important, the pharmaceutical industry is now developing medications to help prevent this lean tissue loss that is happening with the expanding use of GLP-1 therapy. While that may be important for certain classes of patients, there are better, more natural ways at preventing lean tissue loss while on these medications. Furthermore, the same strategies I describe in this article are things you should already be doing to maintain optimal health. They are also crucial strategies for any weight loss program to both enhance the weight loss on therapy, and maintain that weight loss after discontinuing the medication. 

The Importance of Lean Muscle Mass to Overall Health 

I can’t stress enough the importance of lean muscle mass with regards to optimal health. Contrary to popular belief, our musculoskeletal system is actually the largest organ system in the human body. Furthermore, it is an organ system that we can directly influence and optimize through our daily habits. The fact that we can directly influence this organ system is incredibly empowering. Lean muscle mass is crucial for overall health. Let me explain why this organ system is so crucial, and what we can do to optimize and maintain this system for optimal health and longevity.   

Lean muscle mass is more than just a marker of physical strength or athletic prowess. It plays a vital role in numerous aspects of overall health and well-being. From metabolic function to physical capability, muscle mass influences many areas that contribute to a healthy, active life. Here’s an in-depth look at why lean muscle mass is so important. 

Metabolic Health: Basal Metabolic Rate (BMR): 

Lean muscle mass significantly contributes to the body's basal metabolic rate (BMR), which is the number of calories your body needs to maintain basic physiological functions at rest. Muscle tissue is metabolically active, meaning it burns more calories at rest compared to fat tissue. It produces much of the heat generated by our body. Higher muscle mass leads to a higher BMR, which can help with weight management and reduce the risk of metabolic disorders such as obesity and type 2 diabetes.  

Glucose Regulation: 

Muscles play a crucial role in glucose metabolism. Muscle tissue has a high appetite for glucose. It helps regulate blood sugar levels due to high metabolic demand. This is why placing a demand on this tissue through exercise and resistance training is crucial. The more we ask of our muscles, the better they will respond to that demand by upregulating the cellular machinery of energy production to meet that demand. Increased muscle mass also improves insulin sensitivity, reducing the risk of insulin resistance and type 2 diabetes. Engaging and challenges our muscles multiple times per week is a powerful tool we can engage in to improve our metabolic health. 

Physical Function and Mobility: Strength and Endurance 

Lean muscle mass is essential for physical strength and endurance. Strong muscles support daily activities, from lifting groceries to climbing stairs, and contribute to overall stamina. This becomes increasingly important as we age, as muscle mass naturally declines as we get older (a condition known as sarcopenia), leading to frailty and decreased physical capabilities. Resistance training and muscle strength are also closely linked to bone health. The stress that muscles exert on bones during weight-bearing activities stimulates bone formation and increases bone density. This can help prevent osteopenia/osteoporosis and reduce the risk of fractures.  

Numerous studies have linked higher lean muscle mass with overall reduced risk of mortality and improved health outcomes. You heard that right: more muscle mass reduces your overall risk of dying. Even more impressive, total quantity of muscle mass is one of the factors that contributes the greatest to overall risk reduction out of any modifiable health behavior. Fascinating!  

Alright, hopefully you are convinced on the importance of maintaining and even building up lean tissue mass. But how do we achieve this? Read on for the best, natural strategies to optimize lean tissue mass. 

Protein Intake: A Key Component 

 Adequate protein intake is vital for maintaining muscle mass. Protein provides the building blocks (amino acids) that muscles need to repair and grow. When on GLP-1 receptor agonist therapy, ensuring sufficient protein intake becomes even more important. These medications often lead to reduced appetite, which might result in lower overall food intake, including protein. 

How Much Protein Do You Need? 

For most adults, the recommended dietary allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day. However, during weight loss or when aiming to preserve or increase muscle mass, this requirement increases. Studies suggest that an intake of 1.2 to 2.0 grams per kilogram of body weight (around 0.9 grams per pound) per day is more effective for preserving muscle mass during weight loss. Even higher amounts may be beneficial, if we have a goal of growing our lean mass.  

Protein-Rich Foods 

Incorporate a variety of protein-rich foods into your diet. Good sources include: 

- Lean meats (chicken, turkey, lean beef) 

- Fish and seafood 

- Eggs 

- Dairy products (milk, yogurt, cheese) 

- Plant-based proteins (beans, lentils, tofu, tempeh, quinoa) 

Some people can benefit from supplementation with protein, including adding protein powders to foods, smoothies, or shakes. This may be particularly important for those patients who struggle with consuming large volumes of food or have a poor appetite, which can be a common effect on GLP-1 agonist therapy.  

The Role of Resistance Training 

While protein intake is crucial, it is not sufficient on its own. You can think of protein intake as the building blocks needed to make muscle. But we need the real-life stimulus of resistance training and engaging our muscles for our body to truly respond. Resistance training is another essential component for preserving lean muscle mass. Engaging in regular resistance exercise stimulates muscle protein synthesis and helps maintain, or even increase, muscle mass during weight loss. 

Types of Resistance Training 

Resistance training involves any exercise that cause muscles to contract against an external resistance. This can be achieved through: 

- Free weights (dumbbells, barbells) 

- Weight machines 

- Resistance bands 

- Bodyweight exercises (push-ups, squats, lunges, etc.) 

Exercise Recommendations:

Aim for at least three resistance training sessions per week, or more if possible. Focus on all major muscle groups, including the legs, back, chest, core, and arms. Compound movements that engage multiple muscle groups simultaneously are amazing for efficiently promoting muscle gain. While there are many different protocols highlighting the amount of repetitions and sets one should perform with each exercise, the main driver for driving growth is performing the exercise until you are close to failure. This ensures you are adequately placing a high demand on the tissue to cause the adaptative changes we are looking to achieve. Furthermore, consistency is key to seeing results and preserving muscle mass. 

Other factors for optimizing muscle mass 

 Although adequate protein intake and resistance training are probably the two most important factors to drive the results we are looking for, there are many other aspects of our health that are worth optimizing to enhance results. Briefly, these include: 

Hydration: Stay well-hydrated to support muscle function and recovery. 

Adequate Sleep: Aim for 7-9 hours of quality sleep per night to facilitate muscle repair and overall health. The first few hours of our sleep are particularly important, as this time period is crucial for growth hormone release, a hormone which has an important role in growth, repair, and recovery of lean tissue mass.  

Conclusion

Lean muscle mass is a cornerstone of overall health. It influences metabolic health, physical function, bone density, cardiovascular health, mental well-being, and longevity. By prioritizing strategies to build and maintain muscle, you can enhance your quality of life, reduce the risk of chronic diseases, and promote healthy aging. If you are on GLP-1 receptor agonist therapy or any other weight loss regimen, integrating these strategies is even more critical to ensure you reap the full benefits of your treatment while maintaining optimal health. Always consult with your healthcare provider before making significant changes to your diet or exercise routine to ensure they are safe and effective for your specific needs.