How to Prevent Muscle Atrophy While on Weight Loss Medication

Weight loss can be a challenging journey, and while medications like semaglutide have proven effective in aiding this process, maintaining muscle mass during weight loss remains a critical consideration. Muscle plays a vital role in overall health, metabolism, and physical functionality, so preserving it should be a priority when working toward weight loss goals. Here are actionable strategies to help you maintain muscle mass while losing fat with the assistance of semaglutide.

Body composition changes with semaglutide: weight decreased from 146.5 lb to 141.7 lb, skeletal muscle mass dropped from 50.9 lb to 46.5 lb, while body fat percentage increased from 35.7% to 38.7%.

1. Understand Semaglutide and Its Effects

Semaglutide is a glucagon-like peptide-1 (GLP-1) receptor agonist that helps regulate blood sugar levels and suppress appetite. Initially developed for diabetes management, it has gained popularity as a weight loss aid. While semaglutide can promote significant fat loss, its appetite-suppressing effects might inadvertently lead to reduced protein and calorie intake, which can put muscle mass at risk. Understanding this helps in proactively countering potential muscle loss.

2. Prioritize Protein Intake

Protein is essential for building and maintaining muscle. In order to preserve muscle mass during a calorie deficit, it’s important to consume sufficient high-quality protein. When the body is in a calorie deficit and energy demands exceed the available glucose and fat stores, it may begin to catabolize muscle tissue as an alternative energy source. This process involves breaking down muscle proteins into amino acids, which are then converted into glucose through gluconeogenesis in the liver to supply energy for vital functions. While this mechanism helps maintain energy balance during prolonged calorie restriction, excessive muscle catabolism can lead to loss of strength, reduced metabolic rate, and impaired physical performance. Preventing muscle breakdown requires prioritizing protein intake, engaging in resistance training, and avoiding extreme calorie deficits. While the Daily Recommended Intake of protein (DRI) is about 0.8 grams per kilogram of body weight, in the absence of chronic kidney disease (CKD), you can safely aim for 1.2 to 2.0 grams of protein per kilogram of body weight daily, tailored to your activity level. Include protein-rich options like:

• Lean white and dark meats (chicken, turkey, and lean beef)

• Fish and shellfish 

• Eggs and dairy products (Greek yogurt, cheese, milk)

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

• Protein supplements (whey, milk, or plant-based protein powders) Always consult your doctor before starting any supplements, especially while taking semaglutide.

Distribute your protein intake evenly throughout the day to optimize muscle protein synthesis. try to have a portion of protein with every meal. Meals containing ≥30 g of high-quality protein, defined by a balanced profile of essential amino acids including ≥2.5 g of leucine, can optimize muscle health.

3. Strength Training is Essential

Strength training is one of the most effective ways to preserve muscle mass during weight loss. Incorporate resistance exercises into your weekly routine, aiming for at least 2-3 sessions per week. Focus on compound movements such as squats, deadlifts, bench presses, and rows, which target multiple muscle groups. Gradually increase the intensity or volume to continue challenging your muscles as you lose weight.

4. Manage Your Calorie Deficit

While semaglutide can suppress appetite and lead to a calorie deficit, it’s important to avoid excessive calorie restriction. Severe deficits can accelerate muscle loss. Work with a dietitian to calculate a moderate deficit that allows for steady fat loss while preserving muscle mass. A deficit of 500-1000 calories per day is generally considered safe and sustainable. Keep in mind that a more aggressive weight loss increases the risk of muscle loss and atrophy.  

5. Monitor Progress

Track your body composition regularly to ensure that you are losing fat, not muscle. Tools like bioelectrical impedance scales, DEXA scans, or even simple circumference measurements can provide valuable insights. Adjust your nutrition and training regimen based on your results.

6. Stay Hydrated and Get Adequate Sleep

Hydration and recovery are often overlooked but essential components of muscle preservation. Dehydration can impair muscle function, and sleep is crucial for muscle repair and recovery. Aim for 7-9 hours of quality sleep per night and drink plenty of water throughout the day.

7. Seek Professional Guidance

Weight loss and muscle maintenance are complex processes, especially when medications like semaglutide are involved. Work with a healthcare provider, dietitian, or fitness professional to develop a personalized plan that aligns with your goals and ensures safety.

Final Thoughts

Semaglutide can be a powerful tool for weight loss, but preserving muscle mass during the process requires intentional effort. By combining a protein-rich diet, regular strength training, a moderate calorie deficit, and smart supplementation, you can achieve your weight loss goals while maintaining the muscle that supports your overall health and performance. Remember, the key is balance—losing fat while keeping muscle intact will help you look and feel your best throughout your journey.

By Kamran Dehghan, RDN, CDN, CPT