Dr. Stuart Phillips is a Distinguished University Professor in the Department of Kinesiology and a member of the School of Medicine at McMaster University. He is a Tier 1 Canada Research Chair in Skeletal Muscle Health. Dr. Phillips' work centers on the interaction of exercise/physical activity, aging, and nutrition in skeletal muscle and body composition. Dr. Phillips is a fellow of the American College of Sports Medicine (ACSM) and the Canadian Academy of Health Sciences (CAHS). His research focuses on the role of nutrition, hormones, and exercise and their interactive effects on human skeletal muscle protein turnover and phenotypic adaptation.
GLP-1 receptor agonists (GLP-1RAs) have emerged as powerful tools for weight loss in individuals with obesity and cardiometabolic disease. However, their efficacy in reducing body weight comes with a significant caveat: concomitant loss of lean mass, which can account for 25–40% of total weight lost during treatment. As skeletal muscle is not only critical for physical function but also a metabolically active organ essential for glucose homeostasis, immune function, and endocrine signalling, its preservation is vital for long-term health outcomes. This presentation will explore how targeted nutritional strategies, particularly adequate protein intake, combined with resistance training, can mitigate muscle loss and enhance the quality of weight loss, defined not merely by fat reduction, but by improvement in body composition. The session will address the emerging evidence on muscle changes during GLP-1RA therapy, discuss practical interventions for clinicians, and align with case-based learning relevant to the clinical management of weight loss in patients.
The ‘Power’ of Protein in Body Weight Regulation: Preserving Muscle in the Era of GLP-1RA Therapy
Learning Objectives:
- Describe the role of skeletal muscle as both a structural and metabolic organ, and explain the clinical consequences of its loss during weight reduction, particularly in the context of GLP-1RA therapy.
- Evaluate the evidence on the extent and implications of muscle loss with GLP-1RA-induced weight loss, including risks of sarcopenic obesity.
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Identify evidence-based strategies, including dietary protein intake and resistance exercise, to preserve muscle mass and improve the quality of weight loss during pharmacologically-induced weight reduction.