Malnutrition is highly prevalent among critically ill patients admitted to intensive care units (ICUs) and is strongly associated with poor clinical outcomes including prolonged ICU stay, increased duration of mechanical ventilation, higher risk of infections, and increased mortality. Accurately diagnosing malnutrition early in these patients is essential to initiate timely nutritional interventions and improve clinical outcomes. Traditionally, the Subjective Global Assessment (SGA) has been the reference standard tool for diagnosing malnutrition in hospitalized patients. However, the SGA has limitations in ICU settings, where patients are often sedated, mechanically ventilated, or unable to provide their clinical history, reducing its applicability and accuracy.

The Global Leadership Initiative on Malnutrition (GLIM) criteria, developed in 2018, offer a new consensus framework for diagnosing malnutrition through a two-step process: first identification of nutritional risk, followed by diagnosis using phenotypic criteria (such as weight loss, low BMI, or reduced muscle mass) combined with etiologic criteria (such as reduced food intake or inflammation). Recent research suggests that combining GLIM criteria with validated nutritional risk screening tools like Nutritional Risk Screening 2002 (NRS-2002) and modified Nutrition Risk in Critically Ill (mNUTRIC) score enhances the detection and prognostic accuracy of malnutrition in ICU patients.

This prospective observational study conducted in the Indian ICU setting aims to compare the diagnostic accuracy and predictive validity of GLIM alone, GLIM combined with NRS-2002, and GLIM combined with mNUTRIC against SGA. The study will also evaluate the prevalence of malnutrition detected by these tools and their ability to predict important ICU outcomes, including length of stay, duration of mechanical ventilation, vasopressor use, and mortality. The findings will provide critical data to validate and optimize malnutrition assessment protocols in critically ill Indian patients and support better clinical decision-making toward personalized nutritional support in critical care.