Personal tools
You are here: Home Dietetics Our Hospital Based Services MUST- Malnutrition Screening Tool

MUST- Malnutrition Screening Tool

Malnutrition Universal Screening Tool(MUST)

‘MUST’ is a five-step screening tool to identify adults, who are malnourished, at risk of malnutrition (undernutrition), or obese. It also includes management guidelines which can be used to develop a care plan.

It is for use in hospitals, community and other care settings and can be used by all care workers.

When to use this tool

MUST should be measured for all inpatients on admission and then weekly during their hospital stay.

5 Steps to Assess Nutritional Status

Step 1

Measure height and weight to get a BMI score using the chart provided. If unable to obtain height and weight, use the alternative procedures shown in this guide.

Step 2

Note percentage unplanned weight loss and score using tables provided.

Step 3

Establish acute disease effect and score

Step 4

Add scores from steps 1, 2 and 3 together to obtain overall risk of malnutrition.

Step 5

Use local policy to develop care plan.

Body Mass Index (BMI) Ready-Reckoner

Why not try our online BMI Calculator (here)


Height (Feet & Inches)

Body Mass Index (BMI) Ready-Reckoner Chart

Height (Metres)

To calculate BMI using chart:

1 2 3

Weigh the patient without shoes

Measure the patients height without shoes

Place a ruler on the ready reckoner along the patients weight. Read the BMI score where their weight line crosses their height line


Height =......m



Alternative measurements


If height cannot be obtained, use length of forearm (ulna) to calculate height using tables below.

Estimating height from ulna length

olecranon3Measure between the point of the elbow (olecranon process) and the midpoint of the prominent bone of the wrist (styloid process) (left side if possible).


Estimating BMI Category from mid arm circumference (MUAC)


The subject’s left arm should be bent at the elbow at a 90 degree angle, with the upper arm held parallel to the side of the body. Measure the distance between the bony protrusion on the shoulder (acromion) and the point of the elbow (olecranon process). Mark the mid-point.


Ask the subject to let arm hang loose and measure around the upper arm at the mid-point, making sure that the tape measure is snug but not tight

If MUAC is < 23.5 cm, BMI is likely to be <20 kg/m2.

If MUAC is > 32.0 cm, BMI is likely to be >30 kg/m2.

Step 2

Calculate percentage weight loss

Why not try our online % weight loss calculator (here)


Step 3

Calculate Acute Disease effect score. If a patient is acutley ill and there has been or is likely to be no nutritional intake for more than 5 days then score 2.

Step 4

Add together scores from steps 1,2 and 3 and this is equal to the malnutrition risk Score

Step 5

Action plan


Document Actions