The Role of the Dietitian in Incretin-Based Obesity Therapies in Italy: Practical Clinical Challenges, Professional Clarity, and the Sarcopenic Obesity Perspective

Background: Incretin-based therapies, including glucagon-like peptide-1 (GLP-1) receptor agonists and dual GLP-1/glucose-dependent insulinotropic polypeptide (GIP) receptor co-agonists, advance obesity treatment by promoting weight loss and lowering the risk of type 2 diabetes and cardiovascular disease. Methods: This narrative review synthesizes clinical evidence to highlight the role of dietitians in obesity management when incretin-based therapies are used. Results: GLP-1 receptor agonists and dual GLP-1/GIP receptor co-agonists achieve 15–21% weight loss and reduce cardiometabolic risk. Their effectiveness and safety are optimized when integrated with medical nutrition therapy (MNT) and personalized nutrition strategies. In Italy’s aging population, the rising burden of sarcopenic obesity requires dietitian-led care to preserve fat-free mass while reducing fat mass. Dual GLP-1/GIP co-agonists show superior reductions in visceral adiposity, but effects on fat-free mass remain inconclusive, underscoring the need for dietitian oversight to prevent adverse body-composition changes. Sarcopenic obesity is associated with increased mortality and functional decline. Dietitians are uniquely qualified to ensure adequate protein intake and protect muscle during pharmacologic interventions. In Italy, role clarity in clinical nutrition remains limited; however, under national law (DM 744/94; Law 42/1999), dietitians are recognized as the professionals authorized to provide medical nutrition therapy (MNT). Conclusions: The dietitian’s expertise maximizes therapeutic efficacy, minimizes adverse effects, and safeguards long-term outcomes. Integrating dietitians into pharmacological treatment pathways is essential to optimize outcomes, ensure patient safety, and safeguard long-term metabolic health.