GLIM Malnutrition Criteria Interpreter
GLIM Malnutrition Criteria Interpreter
The GLIM consensus criteria applied exactly as published: one phenotypic criterion and one aetiologic criterion are both required, and severity is graded on the phenotypic criteria alone. A positive screen comes first.
GLIM criteria for the diagnosis of malnutrition
3 phenotypic, 2 aetiologicWeight loss 8% over 4 months; BMI 21.5 at age 54; muscle mass not assessed; intake under half of requirement for 10 days; acute pneumonia
The GLIM criteria, as published
Non-volitional weight loss above 5% within 6 months, or above 10% beyond 6 months
Low BMI: below 20 if under 70 years, below 22 if 70 or over (Asia: below 18.5, or below 20)
Reduced muscle mass, by validated body-composition measuring techniques
AND at least ONE aetiologic criterion
Reduced food intake or assimilation: 50% or less of requirement for more than 1 week, any reduction for more than 2 weeks, or any chronic gastrointestinal condition impairing assimilation
Inflammation: acute disease or injury, or chronic disease-related
- one of each, not two of five
- the commonest misreading. All three phenotypic criteria with neither aetiologic criterion does NOT meet GLIM, and nor does both aetiologic criteria with no phenotypic one. This page names both situations rather than returning a bare negative
- severity is phenotypic only
- stage 1 (moderate) and stage 2 (severe) are graded on the three phenotypic criteria alone, and the most severe finding sets the stage — so florid inflammation does not upgrade a patient whose weight loss is 6%. The thresholds are in the table below
- screening comes first
- GLIM is two-step: screening with a validated tool, then assessment against these criteria. This page does the second step only, and reproduces no screening instrument — ‘MUST’ is distributed under a BAPEN permission scheme with a published commercial fee schedule, so it is named here and left alone, with no paraphrase offered in its place
- which version, and the muscle-mass gap
- the 2019 consensus report. The 2025 five-year update states that “no revisions of the weight loss, low BMI, or reduced food intake/assimilation criteria are suggested”, so these thresholds are current; what it changed was guidance on HOW to assess muscle mass and inflammation. GLIM names no single muscle-mass cut-off, because validated thresholds are method- and population-specific, so this page takes the assessor’s categorisation rather than computing it
Worked example
Weight loss 8% over 4 months; BMI 21.5 at age 54; muscle mass not assessed; intake under half of requirement for 10 days; acute pneumonia
Weight loss 8% within 6 months falls in the 5–10% band: phenotypic criterion met at the stage 1 level
BMI 21.5 at age 54 is at or above the cut-off of 20 for under-70s: not met. Muscle mass not assessed: cannot contribute. Phenotypic criteria met: 1 of 3, which satisfies the "at least one" requirement
Intake under 50% of requirement for more than a week, and acute pneumonia: 2 of 2 aetiologic criteria
One phenotypic and one aetiologic: the criteria are met. No phenotypic criterion reaches the stage 2 threshold, so stage 1, moderate malnutrition
Change the weight loss to 12% over 4 months and the same patient becomes stage 2 — one phenotypic criterion at the severe threshold is enough
Now remove both aetiologic criteria and the answer becomes criteria not met even with 12% weight loss. One of each is required, and the page says which half is missing
Phenotypic criteria, and the severity thresholds
| Phenotypic criterion | Stage 1, moderate | Stage 2, severe |
|---|---|---|
| Non-volitional weight loss | 5–10% within the past 6 months, or 10–20% beyond 6 months | Above 10% within the past 6 months, or above 20% beyond 6 months |
| Low body mass index (kg/m²) | Below 20 if under 70 years; below 22 if 70 or over | Below 18.5 if under 70 years; below 20 if 70 or over |
| Reduced muscle mass | Mild to moderate deficit, by validated body-composition measurement | Severe deficit, by validated body-composition measurement |
Aetiologic criteria, either of which is enough
| Aetiologic criterion | As published |
|---|---|
| Reduced food intake or assimilation | 50% or less of energy requirement for more than 1 week, any reduction for more than 2 weeks, or any chronic gastrointestinal condition impairing assimilation |
| Inflammation or disease burden | Acute disease or injury, or chronic disease-related. The 2025 update states that clinical judgment “may suffice” here |
One of each, and severity from the phenotype alone
Before GLIM there was no agreed way to diagnose malnutrition, and studies could not be compared because each used its own definition. The Global Leadership Initiative on Malnutrition — ESPEN, ASPEN, PENSA and FELANPE together — published a consensus set in 2019 with a deliberately simple structure: three phenotypic criteria that describe the state, two aetiologic criteria that attribute it to a cause, and a requirement for at least one from each group.
That requirement is the part most often got wrong. Two phenotypic criteria are not enough however severe: a patient with 20% weight loss, a BMI of 17 and a severe muscle deficit does not meet GLIM unless reduced intake or assimilation, or inflammation and disease burden, is also present. Nor do two aetiologic criteria alone mean anything — a septic patient eating nothing has not met GLIM until a phenotypic criterion appears. This page reports those two situations separately and says which half is missing, because a bare negative hides the difference between a well-nourished patient and an incomplete assessment.
Severity is graded on the phenotypic criteria alone, and the most severe finding sets the stage — so florid inflammation does not upgrade a patient whose weight loss is 6%. The time frames matter as much as the percentages: 8% over six months is a finding and 8% over two years is not.
Two honest limitations. The muscle-mass criterion has no single cut-off by design, because validated thresholds are method- and population-specific; the 2025 five-year update says assessment “should be guided by experience and available technological resources”, and confirms the weight loss, BMI and intake criteria are unchanged. So this page takes the assessor’s categorisation, and a muscle mass recorded as not assessed cannot contribute — which makes an incomplete assessment look negative unless the reader notices. And GLIM is the second step of a two-step approach, applied after a positive screen with a validated tool that this page does not perform and deliberately does not reproduce: ‘MUST’ is distributed under a BAPEN permission scheme with a published commercial fee schedule and the requirement that it “needs to be reproduced exactly”, so it is named here and left alone, with no lookalike offered in its place. Albumin-based indices answer a different question and are not GLIM criteria — see the Geriatric Nutritional Risk Index and the Prognostic Nutritional Index. This page computes a figure and prints the published targets beside it with the guideline each comes from. The prescription is the clinician’s, taken with the patient in front of them.
Frequently asked questions
What are the GLIM criteria?
Three phenotypic criteria — non-volitional weight loss above 5% within 6 months or above 10% beyond; a low BMI, below 20 under age 70 or below 22 at 70 and over, with Asian cut-offs of below 18.5 and below 20; and reduced muscle mass by validated body-composition measurement — plus two aetiologic criteria: reduced food intake or assimilation, and inflammation or disease burden. At least one from each group is required.
How many criteria are needed for a GLIM diagnosis?
One from each group, not two from the five. Three phenotypic criteria with no aetiologic criterion do not meet GLIM, and two aetiologic criteria with no phenotypic criterion do not either. This page names both situations so it is clear which half is missing.
How is GLIM severity staged?
On the phenotypic criteria alone, with the most severe finding setting the stage. Stage 1: weight loss 5 to 10% within 6 months or 10 to 20% beyond, BMI below 20 under 70 or below 22 at 70 and over, or a mild to moderate muscle deficit. Stage 2: weight loss above 10% or above 20%, BMI below 18.5 or below 20, or a severe muscle deficit. The aetiologic criteria do not affect the stage.
Which version does this implement, and has GLIM changed?
The 2019 consensus report, checked against the 2025 five-year update, which states that “no revisions of the weight loss, low BMI, or reduced food intake/assimilation criteria are suggested”. What it changed was guidance on how to assess the other two: muscle mass “should be guided by experience and available technological resources”, and clinical judgment “may suffice” for inflammation.
Do I need a screening tool first?
Yes. GLIM is a two-step approach and this page performs only the second step. It reproduces no screening instrument: ‘MUST’ is distributed under a BAPEN permission scheme, free for UK health and social care and for education and research but carrying a published commercial fee for apps and electronic records, with the requirement that the tool “needs to be reproduced exactly”. Use whichever validated tool your institution licenses.
Related calculators
References
- Cederholm T, Jensen GL, Correia MITD, et al. GLIM criteria for the diagnosis of malnutrition — a consensus report from the global clinical nutrition community. Clin Nutr. 2019;38(1):1–9. The three phenotypic and two aetiologic criteria, the requirement for at least one of each, and the stage 1 and stage 2 severity thresholds reproduced on this page.
- Jensen GL, Cederholm T, Correia MITD, et al. GLIM consensus approach to diagnosis of malnutrition: a 5-year update. JPEN J Parenter Enteral Nutr. 2025;49(4):414–427. “No revisions of the weight loss, low BMI, or reduced food intake/assimilation criteria are suggested”; muscle-mass assessment “should be guided by experience and available technological resources”.
- BAPEN. ‘MUST’ user categories and costs, and the application form for permission to use ‘MUST’. Free for UK health and social care and for education and research worldwide; £20,000 + VAT for an international app or electronic patient record, and “‘MUST’ needs to be reproduced exactly”. The reason ‘MUST’ is named on this site and not reproduced.
- Volkert D, Beck AM, Cederholm T, et al. ESPEN practical guideline: clinical nutrition and hydration in geriatrics. Clin Nutr. 2022;41(4):958–989. Recommendation 1, a guiding value of 30 kcal per kg body weight per day; recommendation 2, at least 1 g protein per kg body weight per day. Both Grade B.
Not medical advice. For healthcare professionals and education. Reference intervals vary by laboratory and assay — always use your own laboratory's. Never base a dose or a treatment decision on this page alone. Full disclaimer at calcengines.com/disclaimer/