The First Step in Identifying Those Who May Be at Risk of Malnutrition

November 21, 2025 •

3 min read

According to the World Health Organization, nearly half of all deaths in children under five are linked to undernutrition. This startling statistic underscores the importance of timely intervention. For both children and adults, the first step in identifying those who may be at risk of malnutrition is through a systematic nutritional screening process using validated tools.

Quick Summary

The initial phase of identifying at-risk individuals involves a nutritional screening process. This uses simple, validated tools to pinpoint risk factors like recent weight loss, decreased appetite, and underlying health conditions, distinguishing those needing further comprehensive assessment from those with low risk.

Key Points

Screening is the First Step: Nutritional screening is the initial, systematic process to identify individuals who are malnourished or at risk.
Use Validated Tools: Rely on standardized screening tools like MUST, MNA-SF, or MST for consistent and objective risk assessment.
Look for Key Indicators: Critical warning signs include unintentional weight loss, reduced food intake, low BMI, and the presence of underlying diseases.
Holistic Evaluation: Consider clinical and social risk factors such as psychological distress, social isolation, and financial limitations, not just physical signs.
Further Assessment is Next: A positive screening result should trigger a more detailed nutritional assessment by a qualified professional to confirm diagnosis and plan care.

Nutritional Screening: The Vital First Step

Nutritional screening is a rapid process to identify individuals who are malnourished or at risk. This initial step is different from a full nutritional assessment, which is a detailed evaluation by a registered dietitian. Screening allows for early detection and intervention, improving health outcomes and reducing malnutrition complications. A standardized screening should occur within 24 to 48 hours of initial patient contact in various settings.

Core Components of the Screening Process

Initial data collection: Gathering information on food intake, weight history, and changes in appetite or weight.
Identifying key risk factors: Looking for specific factors linked to an increased chance of malnutrition, often using a scoring system.
Utilizing validated tools: Employing standardized tools for reliable risk assessment based on metrics like weight loss.

Common Nutritional Screening Tools

Malnutrition Universal Screening Tool (MUST)

Developed by BAPEN, MUST is widely used. It assesses BMI, unintentional weight loss, and the impact of acute disease on nutrient intake.

Malnutrition Screening Tool (MST)

A simple tool focusing on recent unintentional weight loss and reduced appetite, the MST is quick and suitable for various healthcare settings.

Mini Nutritional Assessment (MNA)

The MNA is designed for older people, using a short questionnaire to identify those at risk before severe symptoms appear.

Table: Comparison of Nutritional Screening Tools


Feature	Malnutrition Universal Screening Tool (MUST)	Mini Nutritional Assessment Short-Form (MNA-SF)	Malnutrition Screening Tool (MST)
Target Population	Adults across all care settings	Elderly individuals (>65 years)	Adults in hospital, outpatient, or institutionalized settings
Key Parameters	BMI, unintentional weight loss, acute disease effect	Weight loss, food intake, mobility, acute illness, psychological stress, BMI	Unintentional weight loss, reduced appetite
Number of Steps/Questions	5 steps	6 questions	2 questions
Time to Complete	Very quick	Quick	Very quick
Risk Categorization	Low, Medium, High risk	Well-nourished, at risk, or malnourished	At-risk if score ≥ 2
Primary Goal	General adult screening	Early detection in older adults	Simple, fast screening

The Screening Process in Detail

Patient History and Anthropometrics

Unintentional weight loss: Significant weight loss over 3-6 months is a key indicator of malnutrition risk. Changes in clothing fit can also be a sign.
Reduced food intake: A decrease in food or fluid intake, often with loss of appetite, is another important sign. Causes can include illness, taste changes, or psychological factors.
Body Mass Index (BMI): While not a sole diagnostic tool, a BMI below 18.5 kg/m² for adults indicates risk. Different cutoffs may apply to older adults.

Clinical and Social Factors

Underlying medical conditions: Conditions like cancer or inflammatory bowel disease increase metabolic needs or hinder nutrient absorption, raising malnutrition risk.
Psychological and social factors: Depression, isolation, difficulty chewing, or financial constraints can affect eating. Screening should consider these factors.

The Role of Authoritative Tools and Further Assessment

Validated screening tools ensure a consistent approach. If screening identifies risk, a comprehensive nutritional assessment by a dietitian follows. This confirms diagnosis and guides intervention.

Conclusion: The Impact of Early Screening

Nutritional screening is crucial for effective malnutrition care. Using simple tools to identify risk factors allows for proactive health management and prevents negative outcomes. This first step is essential and cost-effective, leading to better recovery, reduced healthcare costs, and improved quality of life.

Visit the Academy of Nutrition and Dietetics website for more information on nutritional care processes.

Frequently Asked Questions

The primary purpose is to quickly identify individuals who are malnourished or at risk of malnutrition, to determine if a more detailed nutritional assessment is necessary.

Nutritional screening can be performed by various healthcare professionals or trained staff, and some tools are even designed for self-administration.

Screening should be performed within the first 24 to 48 hours of initial patient contact to enable timely intervention.

If a patient is identified as at risk, a comprehensive nutritional assessment is conducted by a registered dietitian to confirm the diagnosis and develop a care plan.

Yes, many validated screening tools are appropriate for use across various settings, including hospitals, long-term care facilities, and community health centers.

Yes, unintentional weight loss, particularly a significant amount over a short period, is a strong indicator of malnutrition risk and is a key component of many screening tools.

Undiagnosed malnutrition can lead to increased risk of infection, longer hospital stays, slower recovery, and higher mortality rates.