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How to maintain muscle mass while taking weight loss drugs such as Wegovy
Last reviewed: 03.07.2025
The development of glucagon-like peptide-1 (GLP-1) drugs such as Wegovy and Mounjaro has opened a new era in weight management. Although these drugs can lead to significant weight loss, researchers and health professionals have raised concerns about the associated loss of muscle tissue. This special feature examines the challenges associated with assessing changes in muscle mass that accompany weight loss from GLP-1 drugs, the potential impact of muscle loss, and ways to preserve it.
Lifestyle and medications
Lifestyle changes can lead to successful weight loss, but many people find it difficult to achieve and maintain a healthy weight long-term.
Bariatric surgery can cause significant and sustained weight loss, but is generally only recommended for severe obesity. In contrast, drugs such as Wegovy and Mounjaro have been shown to cause weight loss nearly comparable to bariatric surgery.
How do Wegovy and Mounjaro help you lose weight?
GLP-1 agonist drugs, such as Wegovy, mimic the action of the GLP-1 hormone secreted by the gastrointestinal tract. These drugs:
- stimulate insulin secretion,
- slow down gastric emptying,
- reduce the feeling of hunger.
Another hormone, glucose-dependent insulinotropic polypeptide (GIP), has similar functions, and GIP receptors are another target for weight-loss drugs.
For example, tirzepatide, sold under the trade name Mounjaro, binds to both GLP-1 and GIP receptors.
The problem of muscle loss
Although GLP-1 drugs are effective for weight loss, there is concern that they may contribute to loss of muscle mass and function.
Loss of muscle mass and function is common with age and is called sarcopenia. Sarcopenia is associated with:
- decreased physical function,
- deterioration in quality of life,
- increased risk of falls, illness and death.
Dr Christopher McGowan, a gastroenterologist and obesity specialist, said:
"Losing weight at the expense of muscle mass can lead to future problems including decreased basal metabolic rate, decreased strength, decreased fitness, decreased bone density and an increased risk of weight regain. Therefore, it is imperative to focus on maintaining muscle mass."
Why is weight loss associated with muscle loss?
Normal:
People who are overweight or obese usually have more muscle mass than those who are of normal weight. When you lose weight, you lose some of that muscle mass.Improved Muscle Composition:
Losing weight typically results in a decrease in muscle fat and an improvement in muscle composition, but also a decrease in muscle size.Insulin Sensitivity:
Losing weight increases your muscles' sensitivity to insulin, which helps prevent muscle protein breakdown.
How do you know if muscle loss is unhealthy?
Lack of direct measurements:
Most studies measure changes in fat and lean mass, not specifically muscle mass. However, lean mass includes not only muscle but also other tissues (organs, bones, fluids).Imaging techniques:
Magnetic resonance imaging (MRI) can directly assess changes in muscle volume and composition, including fat infiltration.Lack of standards:
Thresholds for defining "unhealthy" muscle mass have not yet been established and depend on gender, weight, height and body mass index (BMI).
Who is at risk?
The most vulnerable groups:
- Elderly people with sarcopenia.
- People with osteopenia or osteoporosis.
- Patients with chronic diseases such as kidney failure.
- People with a sedentary lifestyle or nutritional deficiencies.
How to Maintain Muscle Mass While Taking GLP-1 Supplements?
Protein nutrition:
It is recommended to consume 1.0-1.2 g of protein for every kilogram of desired body weight. For example, a person with a desired weight of 68 kg needs 70-80 g of protein daily.Physical activity:
Strength training (2 times a week for 30 minutes) helps maintain muscle mass and improve its function.Dosage Monitoring:
If side effects such as nausea or bloating interfere with dietary compliance, your dose may need to be adjusted.Dietitian:
Working with a dietitian can help you create a personalized meal plan and achieve optimal protein intake.Supplements:
Whey protein or amino acid supplements may be helpful in increasing muscle protein synthesis.
Conclusion
Although weight loss caused by GLP-1 drugs may be accompanied by a loss of muscle mass, these changes are generally as expected. However, it is important to focus on maintaining muscle mass through a protein-rich diet, physical activity, and medical supervision.