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Calculator · Malnutrition risk, in three steps
MUST — malnutrition screening
Done on every admission by nursing staff and asked about on every ward round — which is a good reason to know how it is put together rather than reading the number off the chart.
What it asks
| Criterion | Points |
|---|---|
| BMI | Above 20 — 0 18.5 – 20 — 1 Below 18.5 — 2 |
| Unplanned weight loss in the last 3–6 months | Less than 5% — 0 5 – 10% — 1 More than 10% — 2 |
| Acutely ill AND no nutritional intake for more than 5 days Or likely to have none for the next 5 days — this step is about the trajectory, not today | No — 0 Yes — 2 |
How to read the score
| Score | Means | What to do |
|---|---|---|
| 0 | Low risk | Routine care, and repeat the screen weekly as an inpatient. MUST is a screen: a score of 0 on admission says nothing about day 10. |
| 1 | Medium risk | Observe. Document intake for 3 days; if it is inadequate, escalate to the dietitian. |
| 2–6 | High risk | Refer to dietetics, improve and increase intake, and monitor. In a genuinely starved patient, consider refeeding risk BEFORE feeding starts. |
Before you use it
The step people skip is the third: acutely unwell AND likely to have no intake for over five days scores 2 on its own, so a well-nourished patient nil by mouth after surgery can be high risk with a perfectly normal BMI. And a high score in someone profoundly starved is a REFEEDING warning as much as a feeding one — check phosphate, potassium and magnesium, and give thiamine before the calories.
Source: BAPEN Malnutrition Universal Screening Tool
Checked, and shown
Every threshold on this page was checked against its primary source by a practising doctor. Here is what that involved, and what it found.