Subjective global assessment (SGA) - Diagnosing Malnutrition

Patients identified to be at nutrition risk require a diagnosis to confirm malnutrition. Subjective global assessment (SGA) is the gold standard for diagnosing malnutrition. SGA is a simple bedside method used to diagnose malnutrition and identify those who would benefit from nutrition care. The assessment includes taking a history of recent intake, weight change, gastrointestinal symptoms and a clinical evaluation. SGA has been validated in a variety of patient populations. 

CMTF’s 2022 SGA Video Collection© is a wonderful resource for all levels of clinicians and educators interested in learning about using SGA to assess malnutrition in adults. For more details on this tool, CLICK HERE.

How do I diagnose malnutrition? (expand +/-)

Subjective global assessment (SGA) ( is the gold standard for diagnosing malnutrition. It is also recommended by CMTF for triaging nutrition care. SGA is a simple bedside method used to diagnose malnutrition and identify those who would benefit from nutrition care. It provides an accurate diagnosis in 10 minutes. SGA has been validated in a variety of patient populations and is used extensively worldwide to diagnose malnutrition. The SGA assessment includes:

  • Changes in recent food/fluid intake
  • Weight change
  • Gastrointestinal symptoms and other reasons for low intake
  • Physical exam for wasting of muscle and fat
Remember that SGA only determines protein-energy malnutrition; there may be other reasons for a dietitian assessment and treatment of patients.

When should SGA be used? (expand +/-)

Dietitians or other trained professionals should conduct SGA within 24 hours of screening a hospital patient as ‘at risk’. SGA should also be used when nutrition risk screening is not possible or necessary for some patients (e.g. those with delirium, dementia, high risk conditions such as trauma, pressure ulcers or SIRS, language difficulties or receiving enteral or parenteral nutrition or recently transferred from critical care). In these cases, SGA should be automatically completed to rule out malnutrition, preferably on the first day of admission. When developing your screening and assessment process for triaging patients, make sure that staff knows the process (i.e. automatic referral) and what to do for these patients who cannot be screened.

How do I triage patients using SGA? (expand +/-)

The SGA score triages patients into SGA A, B or C. Within INPAC, the routes of care for each level are:

  • SGA A (well nourished): Despite screening at nutrition risk, SGA A patients do not require further advanced or specialized care.
  • SGA B (mild/moderate malnutrition): It is left to the discretion and clinical expertise of the professional doing the SGA to determine if a more comprehensive nutrition assessment is required to determine cause of malnutrition, potential micronutrient deficiency, or other investigations that could change the treatment plan.
  • SGA C (severe malnutrition): Patients should receive a more comprehensive assessment.

Key tips (expand +/-)

The following are tips to facilitate detection and treatment of malnutrition using SGA.

  • When the SGA is completed, it is more efficient to immediately continue with the comprehensive nutrition assessment for all SGA C patients, and if deemed appropriate, for SGA B patients.
  • Develop a plan for standardized follow up of patients. This plan is especially relevant to SGA B patients who may be put on advanced care strategies and do not receive a comprehensive assessment automatically.
  • To promote efficiency, SGA B patients can be followed by a diet technician or other nutrition staff member.
  • At the point of identifying malnutrition, consider what strategies can be put in place immediately for SGA B and C patients and order these (e.g. medpass, food preferences).
  • Medpass (small amount of oral nutritional supplement provided by nursing) is a common strategy used for all SGA B and C patients.

Subjective Global Nutrition Assessment (SGNA)

Subjective Global Nutrition Assessment (SGNA) is an abbreviated nutritional assessment and considered a gold standard for diagnosing pediatric malnutrition in hospitals. Dietitians or other trained professionals assess growth and weight change, food intake, functional status, and body composition. SGNA is a bedside method and takes approximately 15 minutes to complete. For more information on SGNA, CLICK HERE


INPAC & the INPAC Toolkit

Medical directive - Registered Dietitians to assess and implement, diagnose and communicate malnutrition
Thanks to St. Michael's Hospital in Toronto for sharing this document with CMTF.

Subjective global assessment (SGA) form – 2017 colour or black & white
The Canadian Malnutrition Task Force, under the leadership of Dr. Jeejeebhoy, revised the SGA form to better reflect the effect dietary intake has on body composition. As well, the form includes detail around the importance of understanding the difference poor appetite and cachexia have on body composition. The form has been incorporated into the 2022 SGA Video Collection.

How to use the SGA form - colour or black & white
This two page form provides the necessary details to assist you in understanding how to complete SGA.

SGA Presentation
This PowerPoint presentation explains why SGA is part of the algorithm INPAC and it shows examples of well-nourished (SGA A), mildly/moderately (SGA B) and severely malnourished patients.

Frequently Asked Questions from dietitians who use SGA

SGA in a Nutrition Assessment
Example of incorporating SGA into a nutrition assessment

A dietitian’s perspective of using SGA in her practice
This brief article describes the positive change in this dietitian’s practice

Review of SGA, focusing on when and how to effectively use it in everyday practice. Dr Khush Jeejeebhoy, MB
CMTF presentations from the Annual CNS Meeting – June 2014

The SGA form and guidance document in pocket guide format

Case study of patient and chart note
This is an example of a chart note using Nutrition Care Process Terminology

Statistics Canada reference values for maximum grip strength, by sex and age
The source of this information is the 2007 to 2013 Canadian Health Measures Survey

Differentiating malnutrition, cachexia and sarcopenia

Acknowledgment: The ideas and resources included on this page are provided in part by the hospitals involved in the More-2-Eat project.

SGA Video Collection© May 2022 copyright Canadian Malnutrition Task Force, Canadian Nutrition Society.

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