Prevent Muscle Loss on GLP-1s and After Bariatric Surgery
GLP-1 medications and bariatric surgery can be life-changing. However, they also come with challenges, including reduced muscle mass. As a result, taking steps to prevent muscle loss while losing weight is essential. Otherwise, losing too much muscle can slow metabolism, reduce strength, and make long-term weight maintenance more difficult.
What to Know About Muscle Loss While Losing Weight
What if, in just over a year, you lost the same amount of muscle your body would naturally lose over two decades? According to research, trials show that individuals on GLP-1 medications, like semaglutide or tirzepatide, as well as those who have undergone bariatric surgery, can lose 10% or more of their skeletal muscle mass while on treatment—a rate comparable to two decades of aging-related muscle loss in adults over 30.
Losing too much muscle can slow metabolism and make weight maintenance more difficult. To prevent muscle loss, it’s essential to focus on protein intake, strength training, and balanced nutrition to help ensure weight loss comes primarily from fat rather than muscle.
How GLP-1 Medications and Bariatric Surgery Contribute to Muscle Loss
GLP-1 medications and bariatric surgery promote weight loss by reducing appetite and calorie intake, but they also alter how the body processes and absorbs nutrients. While effective, these treatments can disrupt muscle protein turnover—the balance between muscle breakdown and rebuilding.
- GLP-1 medications work by reducing appetite and slowing digestion, which can make it harder to eat enough protein—a key nutrient for muscle maintenance. Less protein means less muscle-building support, which may contribute to muscle loss over time.
- Bariatric surgery can permanently alter how the body absorbs nutrients, making it more difficult to get enough protein, vitamins, and minerals needed for muscle preservation—even if eating a high-protein diet.
Due to these effects, proactively supporting muscle retention through diet and exercise is essential to prevent excessive lean mass loss during weight loss.
Strategies to Preserve Muscle While Losing Weight
1. Get Enough Protein Throughout the Day
Protein intake is critical for muscle preservation. As a result, without enough protein, the body may break down muscle for energy instead of prioritizing fat loss.
The recommended intake is 1.2 to 1.6 grams per kilogram of ideal body weight. Spreading protein intake throughout the day helps optimize muscle preservation. Aim for 20–30 grams per meal and include protein-rich snacks to support recovery and muscle maintenance.
| Ideal Body Weight | Daily Protein Goal |
| 150 lb (68 kg) | 82–109 g |
| 175 lb (79 kg) | 95–127 g |
| 200 lb (91 kg) | 109–145 g |
Be sure you’re tracking your intake, using Baritastic, most days to ensure you’re reaching your protein goals!
Here are some high protein food sources:
- Meat, Fish, and Poultry – Chicken, turkey, beef, pork, lamb, venison, bison, duck, veal, rabbit, quail, pheasant, goose, and organ meats (liver, heart, kidney)
- Fish and Seafood – Salmon, tuna, cod, halibut, tilapia, sardines, mackerel, trout, shrimp, crab, lobster, scallops, oysters, mussels, and clams
- Eggs and Dairy – Whole eggs, egg whites, Greek yogurt, cottage cheese, ricotta cheese, kefir, hard cheeses (cheddar, parmesan), soft cheeses (mozzarella, feta), and milk
- Soy Products and Meat Alternatives – Tofu, tempeh, seitan, textured vegetable protein (TVP), soy curls, and miso
- Beans and Legumes – Lentils, edamame, chickpeas, black beans, kidney beans, navy beans, pinto beans, fava beans, etc.
- Whole Grains and Seeds – Quinoa, amaranth, buckwheat, hemp seeds, chia seeds, flaxseeds, sunflower seeds, pumpkin seeds, and nutritional yeast
- Protein Supplements – Whey protein isolates, meal replacements, clear protein drinks, pea and rice protein, or protein bars
2. Strength Training for Muscle Retention
Strength training signals the body to preserve muscle and counteract natural muscle loss. To maximize muscle retention, at least two to three resistance training sessions per week help maintain lean mass and support metabolism.
If you’re new to exercise, it’s best to start with bodyweight exercises or resistance bands at home. Then, once you feel comfortable, progress to weights or machines at a gym. A certified personal trainer can help design a routine that matches your fitness level and goals.
Beginner-Friendly Strength Training Options:
- Bodyweight exercises – Squats, lunges, push-ups, glute bridges, and wall sits
- Resistance bands – Rows, lateral raises, bicep curls, and shoulder presses
- Weight training – Dumbbells, kettlebells, or resistance machines
- Functional exercises – Stair climbing, carrying groceries, and sit-to-stands
Before beginning any new workout program, it’s crucial to consult with a healthcare provider. This is especially important if you have underlying medical conditions.
3. Stay Hydrated for Muscle Function
In addition, hydration supports muscle recovery, protein synthesis, and overall performance. Dehydration leads to fatigue and muscle cramps, increasing the risk of muscle breakdown.
- Drink 2–3 liters (8–12 cups) of fluids per day.
- Eat hydrating foods like cucumbers, watermelon, oranges, and leafy greens.
- Monitor hydration by checking urine color—light yellow is ideal.
- Electrolyte beverages support hydration balance.
4. Support Muscle with Micronutrients
In addition, deficiencies in certain vitamins and minerals can impair muscle contraction, slow recovery, and increase the risk of muscle wasting. A high-quality multivitamin helps fill gaps in nutrient intake.
GLP-1 Users:
- High-potency multivitamin with minerals – Over-the-counter multivitamins may not provide sufficient nutrients like vitamin D, iron, and vitamin B12, which are critical for muscle and metabolic health.
- Calcium citrate (1000 mg/day) – Supports bone and muscle function.
- Protein supplementation (if dietary intake is inadequate) – Helps meet daily protein goals.
Bariatric Surgery Patients:
- Bariatric-specific multivitamin with iron – Contains 45 mg iron, 75 mcg (3000 IU) vitamin D, and 350 mcg vitamin B12.
- Calcium citrate (1200–1800 mg/day) – More easily absorbed than other forms.
- Protein supplementation (if dietary intake is inadequate) – Helps preserve muscle mass.
Above all, preserving muscle during weight loss is key to metabolism, strength, and long-term health. By focusing on protein intake, strength training, hydration, and micronutrient support, individuals using GLP-1 medications or undergoing bariatric surgery can optimize weight loss and support lean body mass.
This content is not intended as a substitute for professional medical advice, diagnosis, or treatment. Individuals should always consult with their healthcare professional for advice on medical issues.
References:
- Mechanick et al., 2025. DOI: 10.1111/obr.13841
- Yeh et al., 2022. PMC9285034
- Almandoz et al., 2024. DOI: 10.1002/oby.24067
- Moore et al., 2014. PMC4939566
