How to Check Degree of Malnutrition: A Comprehensive Guide

November 21, 2025 •

4 min read

According to the World Health Organization (WHO), malnutrition encompasses undernutrition, micronutrient deficiencies, and overnutrition. Accurately assessing nutritional status is a critical first step in determining how to check degree of malnutrition and implementing appropriate interventions for better health outcomes.

Quick Summary

This guide details the multidimensional process for evaluating the severity of malnutrition in both adults and children. It covers key methods including physical measurements, laboratory analyses, and dietary evaluations, emphasizing the need for comprehensive and standardized assessments.

Key Points

Combine Methods: Assessing malnutrition requires a combination of anthropometric, biochemical, clinical, and dietary methods to get a complete picture.
Use WHO Standards for Children: For young children, rely on WHO growth charts and MUAC measurements to accurately classify malnutrition severity, distinguishing between moderate and severe cases.
Consider BMI and Weight Loss in Adults: A low BMI (below 18.5) and significant unintentional weight loss (over 5% in 3-6 months) are key indicators for adults.
Look for Clinical Signs: Physical signs like muscle wasting, fluid accumulation (edema), and poor skin or hair quality can be visual cues for nutritional deficiency.
Use Lab Tests for Specific Deficiencies: Biochemical tests for proteins (e.g., prealbumin), vitamins, and minerals can help identify specific nutrient shortfalls.
Incorporate Dietary History: Gather information on recent food intake, appetite changes, and eating habits using tools like a 24-hour recall to understand the root causes.
Utilize Screening Tools: Healthcare professionals can use validated screening tools like MUST and MNA to quickly identify individuals at risk for malnutrition.

Understanding the Fundamentals of Malnutrition Assessment

Assessing the degree of malnutrition is a complex process that relies on multiple indicators rather than a single measurement. The Global Leadership Initiative on Malnutrition (GLIM) and other health organizations recommend a holistic approach, combining phenotypic criteria (physical signs) with etiologic criteria (causes). A comprehensive nutritional assessment is often summarized by the 'ABCD' method: Anthropometric, Biochemical, Clinical, and Dietary assessments.

Anthropometric Measurements

Anthropometry involves taking physical measurements of the body and is a foundational method for identifying undernutrition, particularly in children.

Body Mass Index (BMI): Calculated as weight in kilograms divided by height in meters squared ($BMI = rac{weight(kg)}{height(m)^2}$), BMI is a simple tool to screen for underweight, overweight, and obesity in adults. A BMI below 18.5 is considered underweight and an indicator of possible malnutrition.
Mid-Upper Arm Circumference (MUAC): This measurement is particularly effective for screening children aged 6 to 60 months for severe acute malnutrition (SAM). A MUAC tape is used to measure the circumference of the upper arm, and a reading below 115mm is indicative of SAM.
Growth Charts for Children: For infants and children under five, plotting measurements like weight-for-age, height-for-age (stunting), and weight-for-height (wasting) on WHO growth standards charts is crucial. A z-score below -2 standard deviations of the median often signals moderate malnutrition, while a score below -3 indicates severe malnutrition.
Unintentional Weight Loss: Unexplained, rapid weight loss is a significant indicator of malnutrition in adults. A weight loss of more than 5% within the last 3-6 months or more than 10% in a longer period is a warning sign.

Biochemical Assessments

Laboratory tests provide important objective data that can reveal specific nutrient deficiencies and overall health status.

Proteins: While not a perfect measure, low levels of serum albumin can suggest long-term protein malnutrition. Prealbumin has a shorter half-life, making it a better indicator of recent nutritional changes.
Complete Blood Count (CBC): A CBC can detect anemia, which is often associated with deficiencies in iron, folate, and B12.
Micronutrient Levels: Blood tests can also measure the levels of specific vitamins (e.g., Vitamin A, C, D) and minerals (e.g., zinc, iron) if a deficiency is suspected.
Electrolytes: Monitoring electrolyte levels is critical, especially during the refeeding process for severely malnourished individuals, to prevent potentially fatal complications.

Clinical and Dietary Assessments

Clinical examination and dietary history are essential for a complete diagnosis.

Clinical Signs: A physical examination can reveal many telltale signs, including muscle wasting, loss of subcutaneous fat, pale eyes or inner eyelids (pallor), edema (swelling), brittle hair, and slow wound healing. Observing a child for bilateral pitting edema on the feet is a specific clinical sign for severe malnutrition.
Dietary History: A thorough dietary assessment involves asking about eating habits, food preferences, appetite changes, and recent food intake. Tools like a 24-hour recall or a food frequency questionnaire can help quantify intake and identify potential deficiencies.

Comparison of Malnutrition Assessment Tools

Healthcare professionals use various screening and assessment tools to check the degree of malnutrition. While screening tools identify those at risk, assessment tools provide a more detailed diagnosis.


Feature	MUST (Malnutrition Universal Screening Tool)	MNA (Mini Nutritional Assessment)	GLIM (Global Leadership Initiative on Malnutrition)
Target Population	Adults, especially hospital and care home residents	Elderly patients	Adults in clinical settings
Components	BMI, unintentional weight loss, acute disease effect	Diet, weight changes, mobility, psychological stress	Phenotypic (weight loss, low BMI, reduced muscle) and Etiologic (food intake, inflammation) criteria
Severity Grading	Low, Medium, High risk	Malnourished, At risk, Normal	Moderate (Stage 1), Severe (Stage 2)
Process	Screening tool to identify risk	Screening and assessment tool	Two-step process: Screen then assess
Pros	Quick, simple, widely validated	Comprehensive for geriatric population	Global consensus, clear criteria for diagnosis and severity

Determining Severity in Children

The World Health Organization provides clear guidelines for classifying the severity of acute malnutrition in children aged 6 to 60 months. Moderate acute malnutrition (MAM) is defined by a Weight-for-Height Z-score (WHZ) between -2 and -3 or a MUAC between 115mm and <125mm. Severe acute malnutrition (SAM) is defined by a WHZ below -3 or a MUAC below 115mm, or the presence of bilateral pitting edema. A comprehensive assessment, including clinical examination and checking for complications like bilateral pitting edema, is crucial for determining the appropriate treatment pathway.

Conclusion: A Multi-faceted Approach

Checking the degree of malnutrition is not a one-step process but requires a multi-faceted approach involving anthropometric measurements, biochemical analysis, clinical observation, and dietary history. These methods, along with standardized screening and assessment tools, provide a comprehensive picture of an individual's nutritional status. For accurate diagnosis and proper management, especially in severe cases, the expertise of healthcare professionals, such as dietitians, is essential. Early and accurate assessment, combined with timely intervention, is vital to prevent long-term health complications associated with malnutrition.

For more detailed information on clinical assessment and nutrition care, consult the NCBI Bookshelf resource on Nutritional Assessment.

Frequently Asked Questions

Screening is a quick, initial process using simple tools like questionnaires to identify individuals at risk of malnutrition. Assessment is a more detailed and comprehensive evaluation conducted by a qualified professional to confirm a diagnosis and determine its severity.

In children, severity is often determined using WHO growth standards and z-scores for weight-for-height and height-for-age, along with mid-upper arm circumference (MUAC) and checking for bilateral edema.

Unintentional weight loss is a key indicator in adults. Losing more than 5% of body weight in 3-6 months or having a low Body Mass Index (BMI below 18.5) suggests possible malnutrition.

Visible signs can include muscle wasting, depleted fat stores, brittle hair, pale skin, weakness, fatigue, and swelling (edema) in the arms, legs, or abdomen.

While not always required for screening, biochemical tests (blood samples) are very useful for identifying specific micronutrient deficiencies and monitoring certain protein levels (like prealbumin), especially in clinical settings.

Yes, it is possible to be overweight or obese due to excessive energy intake but still suffer from malnutrition if the diet is deficient in essential vitamins, minerals, and other micronutrients.

A detailed dietary history helps healthcare professionals understand the patterns of food intake, identifying insufficient consumption, poor food quality, or difficulty with eating, which can all contribute to malnutrition.