In this episode, we dive into a recent study led by Dr. Carla Prado published in Lancet Diabetes & Endocrinology, which explores the impact of GLP-1 receptor agonists on muscle loss during weight loss treatments. These medications are widely used for their effectiveness in reducing body weight, but Prado’s research highlights an important concern: the significant loss of lean mass, including muscle, which can make up as much as 39% of the total weight lost with GLP-1 agonists. This rate is notably higher than that seen with non-pharmacological weight loss, where muscle loss is typically 10-30%.

Why does muscle loss matter in weight loss? Muscle is essential not only for strength and movement but also for regulating blood sugar, supporting immune function, and storing amino acids needed for recovery and health. Losing muscle mass, particularly at such a rapid pace, can lead to long-term impacts on physical and metabolic health, especially for older adults or individuals with chronic health conditions. The study raises concerns about potential declines in strength and function and underscores the importance of muscle preservation strategies.

The episode also covers the concept of sarcopenic obesity—a condition marked by low muscle mass and high fat mass—which is associated with increased risks of falls, fractures, and metabolic complications. Sarcopenic obesity is particularly concerning for aging adults and those with comorbidities, and it underscores the need for weight loss approaches that do more than just reduce the number on the scale.

Another key takeaway from Prado’s study is the focus on muscle quality, not just quantity. The study emphasizes that muscle infiltrated with fat, a condition known as myosteatosis, can lead to weaker, less functional muscle even if total muscle mass seems sufficient. Quality of muscle tissue, therefore, is just as important as preserving its mass, and this has implications for assessing muscle health in clinical settings.

Interestingly, research on bariatric surgery patients reveals that muscle strength—particularly handgrip strength—can be maintained even when muscle mass declines. This finding challenges the traditional emphasis on muscle mass alone and supports using strength as a marker of functional health and resilience.

As Prado argues, we may need to shift our approach to weight loss treatments, especially with powerful medications like GLP-1 agonists. Preserving muscle through interventions such as resistance training and adequate protein intake should be prioritized to help individuals maintain physical and metabolic health over the long term.

Join us as we explore these insights and discuss what they mean for anyone considering or undergoing weight loss treatment. Whether you’re a healthcare provider, a patient, or someone interested in the science behind muscle health, this episode offers valuable perspectives on preserving strength and function during weight loss.

Recommended reading:

https://www.thelancet.com/journals/landia/article/PIIS2213-8587(24)00272-9/abstract