Understanding What are the 3 degrees of malnutrition?

October 9, 2025 •

5 min read

According to the World Health Organization (WHO), nearly half of all deaths in children under five are linked to undernutrition. This grim statistic underscores the vital importance of identifying and classifying the severity, as in what are the 3 degrees of malnutrition.

Quick Summary

The degrees of malnutrition, traditionally classified by systems like the Gomez method based on weight-for-age, denote severity. They are categorized as first-degree (mild), second-degree (moderate), and third-degree (severe), each with distinct symptoms and treatment needs.

Key Points

Three Degrees of Malnutrition: The Gomez classification system defines malnutrition severity in three degrees based on weight-for-age: mild (75–89% of median), moderate (60–74% of median), and severe (<60% of median).
Mild Malnutrition Signs: First-degree or mild malnutrition often presents with subtle symptoms like irritability, fatigue, and slight weight stagnation, making early detection difficult.
Severe Acute Malnutrition (SAM): The third-degree is a medical emergency, identified by extreme wasting (marasmus), bilateral pitting edema (kwashiorkor), or both. It carries a high mortality risk without immediate treatment.
Modern Assessment Tools: Modern clinical practice uses WHO Z-scores for children and BMI with additional criteria (weight loss, muscle mass) for adults to more accurately diagnose and grade malnutrition severity.
Refeeding Syndrome Risk: Treating severe malnutrition requires careful medical supervision, especially during refeeding, to prevent dangerous electrolyte shifts known as refeeding syndrome.
Targeted Treatment: Treatment varies significantly with severity, from simple dietary adjustments for mild cases to complex inpatient care involving therapeutic foods and managing complications for severe cases.
Malnutrition is Broader Than Undernutrition: Malnutrition also includes overnutrition (obesity) and specific micronutrient deficiencies, reflecting a more complex challenge than simple calorie deficiency.

Malnutrition: An Overview of Severity

Malnutrition encompasses deficiencies, excesses, or imbalances in a person's intake of energy and nutrients. While the term is often associated with undernutrition, which is a deficiency of calories and protein, it also includes overnutrition and specific micronutrient deficiencies. Assessing the severity of undernutrition is crucial for appropriate diagnosis, management, and treatment. One of the earliest and most referenced classification systems, particularly for children, is the Gomez classification. This system provides a clear framework for understanding the three degrees of malnutrition based on weight-for-age.

The Gomez Classification and the Three Degrees

The Gomez classification, developed in 1956, uses a child's weight relative to the median weight for their age to determine the degree of protein-energy malnutrition. While modern criteria, such as the WHO's Z-scores, are more widely used, the concept of mild, moderate, and severe degrees remains foundational to nutritional assessment. This classification serves as an important historical and conceptual tool for grasping the progression of malnutrition. The three degrees are defined as follows:

First-Degree (Mild) Malnutrition: Characterized by a weight-for-age measurement between 75% and 89% of the standard median.
Second-Degree (Moderate) Malnutrition: Defined by a weight-for-age measurement between 60% and 74% of the standard median.
Third-Degree (Severe) Malnutrition: The most critical stage, marked by a weight-for-age measurement of less than 60% of the standard median.

First-Degree (Mild) Malnutrition

At the mildest level, malnutrition can be insidious and easily missed. The body has not yet undergone significant breakdown of its own tissues. The signs are often subtle and can be mistaken for other issues. Early detection is key to preventing progression to more severe stages. A child might experience stagnation or a slight, persistent weight loss. In adults, an unintentional weight loss of 5-10% over 3-6 months can indicate mild malnutrition.

Symptoms: Symptoms are often nonspecific, including a slightly reduced appetite, irritability, and mild fatigue. In children, a lack of typical cheerfulness may be a sign. The body is not yet overtly emaciated, and the impact may seem minor.
Causes: A slight deficiency in calorie or nutrient intake is the primary cause. This can result from poor dietary habits, lack of knowledge about proper nutrition, or social/environmental factors like limited food access.
Treatment: Management typically involves dietary adjustments and education. Increasing the energy density and nutritional variety of meals is often sufficient. No drastic medical interventions are usually required.

Second-Degree (Moderate) Malnutrition

When malnutrition progresses to a moderate degree, the symptoms become more pronounced as the body begins to break down its fat and muscle reserves for energy. The individual's health is more noticeably impaired, and their vulnerability to illness increases significantly.

Symptoms: Moderate weight loss becomes evident, and fatigue worsens. The immune system starts to weaken, leading to more frequent infections that are harder to fight off. Mental and emotional changes, such as increased lethargy, apathy, and poor concentration, may appear. In children, irritability is accentuated.
Causes: A sustained and more significant inadequacy of protein and energy intake is the main driver. This can be exacerbated by underlying infections or illnesses that increase metabolic demands.
Treatment: Requires more than simple dietary advice. Treatment may involve high-energy and protein nutritional supplements, along with addressing any concurrent infections. Regular monitoring is essential to track weight gain and overall recovery.

Third-Degree (Severe) Malnutrition

This is a critical and life-threatening condition where the body's energy and protein reserves are severely depleted. The body is in a state of organic bankruptcy, and its ability to function is profoundly compromised. Severe acute malnutrition (SAM) is characterized by extreme wasting (marasmus), edema (kwashiorkor), or both.

Symptoms: The clinical picture is stark. In marasmus, there is severe muscle wasting, a lack of subcutaneous fat, and the child's face may have an "old person" look. Kwashiorkor is characterized by bilateral pitting edema (swelling) of the extremities, which can mask the underlying wasting. Apathy, a lack of appetite, skin changes, and susceptibility to overwhelming infections are common. Without immediate and careful medical intervention, the risk of death is very high.
Causes: Chronic, extreme deficiencies in protein and energy, often worsened by persistent infections or poor living conditions. For children, it can result from being weaned to a low-protein, high-carbohydrate diet.
Treatment: Requires immediate inpatient medical care to stabilize the patient. The 10-step WHO plan includes managing hypoglycemia, hypothermia, dehydration, electrolyte imbalances, and infections before initiating refeeding. The refeeding process must be done cautiously to prevent refeeding syndrome, a potentially fatal complication. Special therapeutic foods like F-75 and F-100 are used to facilitate gradual recovery.

The Role of Modern Nutritional Assessment

While the Gomez classification is historically significant, modern healthcare uses more refined tools to diagnose and classify malnutrition. The World Health Organization (WHO) recommends using Z-scores to compare a child's weight-for-age, weight-for-height (wasting), and height-for-age (stunting) against a standard population median. Similarly, for children, the mid-upper arm circumference (MUAC) tape provides a simple and effective measure of wasting, especially in community settings.

For adults, the body mass index (BMI) is a common indicator, with a BMI below 18.5 indicating undernutrition. However, BMI alone is insufficient, and healthcare professionals also consider involuntary weight loss, loss of muscle mass, reduced grip strength, and clinical signs of nutrient deficiencies. The Global Leadership Initiative on Malnutrition (GLIM) provides a consensus framework combining etiologic (cause-related) and phenotypic (physical) criteria for diagnosis and severity grading in adults.

Comparison of the Three Degrees of Malnutrition


Feature	First-Degree (Mild)	Second-Degree (Moderate)	Third-Degree (Severe)
Classification (Gomez)	75-89% weight-for-age	60-74% weight-for-age	<60% weight-for-age
Physical Appearance	No obvious signs of wasting; weight may be stagnant or slightly low.	Noticeable weight loss, reduced fat and muscle reserves.	Extreme wasting (marasmus) or fluid swelling (kwashiorkor).
Common Symptoms	Irritability, low energy, mild fatigue, reduced appetite.	Pronounced fatigue, reduced concentration, increased infections.	Apathy, extreme weakness, bilateral pitting edema or severe wasting.
Immune Function	Largely intact.	Noticeably weakened, increased risk of infection.	Severely compromised, high risk of serious, opportunistic infections.
Treatment Focus	Dietary improvement, nutritional education.	High-energy/protein supplements, addressing underlying illness.	Inpatient medical care, stabilizing metabolism, careful refeeding.
Mortality Risk	Low.	Moderate, with increased risk compared to normal.	Very high without timely intervention.

Conclusion

Understanding what are the 3 degrees of malnutrition provides a critical framework for identifying, assessing, and managing nutritional deficiencies. While modern assessment tools have evolved, the concept of mild, moderate, and severe malnutrition remains essential. Early intervention through dietary changes and education can effectively reverse mild malnutrition. As the condition progresses, more intensive medical care, including targeted nutritional supplements and careful refeeding, becomes necessary to manage complications and reduce mortality risk. Addressing the underlying causes, whether socioeconomic, medical, or educational, is vital to breaking the cycle of malnutrition and promoting long-term health. For further information on the broader spectrum of malnutrition, including obesity and micronutrient deficiencies, consult the World Health Organization's factsheets.

Frequently Asked Questions

Mild malnutrition involves minor weight loss or stagnation with subtle symptoms like irritability and fatigue. Severe malnutrition is life-threatening, with extreme wasting (marasmus), severe swelling (kwashiorkor), significant health complications, and a high risk of death.

Malnutrition in children is measured using standardized tools like WHO growth charts based on Z-scores for weight-for-height (wasting), height-for-age (stunting), and weight-for-age (underweight). Mid-upper arm circumference (MUAC) is also a simple and widely used indicator.

Yes, you can be overweight and malnourished. This can occur due to an excess of energy intake combined with a deficiency of essential micronutrients, a phenomenon sometimes called 'the double burden of malnutrition'.

Moderate malnutrition is associated with more pronounced symptoms than mild cases, including noticeable weight loss, heightened fatigue, reduced immune function, and apathy or poor concentration.

The treatment for severe malnutrition typically begins with inpatient medical care to stabilize the patient by managing immediate dangers like low blood sugar, hypothermia, and infection. A slow, careful refeeding process is then initiated to prevent refeeding syndrome.

Severe malnutrition results from chronic, extreme deficiencies in protein and energy, often exacerbated by underlying infections, diseases, or extreme poverty. It can be a consequence of long-term underfeeding and nutrient deprivation.

Early detection of malnutrition is crucial because it allows for simpler, less invasive interventions, such as dietary changes and education, preventing the condition from progressing to more severe and life-threatening stages that require intensive medical care.

Marasmus is a form of severe acute malnutrition characterized by extreme wasting and a lack of subcutaneous fat due to a severe, prolonged deficiency in both protein and energy.