Implementation of the GLIM (Global Leadership Initiative on Malnutrition) Criteria in Gastrointestinal Oncology: A Narrative Review of Systemic Impact and the Role of Dietitians.

Malnutrition is a common yet frequently underrecognized condition among patients with gastrointestinal cancers, significantly impacting treatment tolerance, postoperative recovery, and long-term outcomes. This narrative review explores the clinical implementation of the Global Leadership Initiative on Malnutrition (GLIM) criteria in gastrointestinal oncology, with a particular focus on its impact on multidisciplinary workflows and the evolving role of clinical dietitians. A structured literature search was conducted using PubMed to identify English-language publications from 2018 to 2025 that included the terms "GLIM," "malnutrition," "gastrointestinal cancer," "nutritional assessment," and "oncology." Fifty-three articles were selected for inclusion based on their relevance to GLIM criteria implementation and interdisciplinary care models in oncologic settings. In clinical practice, the GLIM framework has elevated nutrition care from an ancillary task to a core component of oncology management. The adoption of GLIM criteria encourages interprofessional collaboration, involving surgeons, oncologists, nurses, and dietitians. It also necessitates the use of tools such as bioelectrical impedance analysis and computed tomography to assess muscle mass, as well as laboratory markers of inflammation, further reinforcing the technical competencies required of dietitians. However, barriers remain. Implementation is hindered by limited training, workflow inconsistencies, time constraints, and disparities in access to diagnostic tools, particularly in resource-limited settings. Additionally, institutional variability and lack of integration into reimbursement systems pose systemic challenges. To support sustainable adoption, many institutions have established structured referral pathways, interdisciplinary training initiatives, and electronic health record algorithms for GLIM-based assessment. These efforts are crucial for overcoming barriers and standardizing care. Furthermore, GLIM-based protocols have improved patient engagement and empowered patients to participate more actively in their nutritional care, especially through the use of standardized tools like the Patient-Generated Subjective Global Assessment. Looking forward, further research is needed to validate simplified diagnostic methods, improve equity in access, and assess long-term impacts on survival and quality of life. Policy reforms, including the recognition of GLIM-based malnutrition in coding systems, could enhance institutional incentives for implementation. Ultimately, the GLIM criteria provide not only a diagnostic tool but also a foundational framework for advancing equitable, interdisciplinary, and patient-centered nutrition care in oncology.