Marasmus: The Protein-Energy Malnutrition Caused by Starvation

November 18, 2025 •

3 min read

According to the World Health Organization, around 45% of deaths in children under five in developing countries are linked to malnutrition. This severe nutritional deficiency state is most commonly identified as marasmus, which is the specific type of protein-energy malnutrition caused by starvation.

Quick Summary

Marasmus is a severe form of protein-energy malnutrition resulting from a prolonged and severe deficit of all macronutrients. It leads to extreme muscle wasting, loss of subcutaneous fat, and a visibly emaciated appearance, distinct from the edema seen in kwashiorkor.

Key Points

Marasmus is caused by starvation: This protein-energy malnutrition results from a severe deficiency of all macronutrients, including carbohydrates, protein, and fats.
Key symptom is severe wasting: Marasmus leads to a visibly emaciated appearance due to the extensive loss of both muscle tissue and subcutaneous fat.
Distinct from Kwashiorkor: Unlike kwashiorkor, marasmus does not typically cause edema (swelling) because it is a deficiency of all energy sources, not just protein.
Affects all body systems: Starvation causes the body to break down its own tissues for energy, impairing vital functions such as cardiovascular and immune systems.
Cognitive and developmental risks: In children, marasmus can lead to stunted growth and permanent cognitive impairment if left untreated.
Treatment requires caution: Rehabilitation for marasmus must be handled carefully in stages to avoid life-threatening refeeding syndrome.
Prevalent in developing countries: Marasmus is most common in regions with high poverty and food insecurity, often affecting young children.

Understanding the Effects of Starvation

Starvation is a state of extreme, prolonged, and inadequate nutritional intake, leading to severe consequences for the human body. When the body is deprived of essential macronutrients—proteins, carbohydrates, and fats—it enters survival mode. To meet its energy requirements, the body begins to catabolize, or break down, its own tissues, first from stored fat and then from muscle and organs. This profound deficit of both calories and protein is what defines marasmus.

The Physiological Response to Severe Nutrient Deprivation

In the initial stages of starvation, the body attempts to adapt by lowering its metabolic rate to conserve energy. However, as the deprivation continues, this compensatory mechanism is exhausted. The body's priority shifts to preserving vital organs, which it attempts to do by consuming less critical tissues. This results in the characteristic wasting seen in marasmus. The body's immune system is also severely compromised, making the individual highly susceptible to infections. Children, in particular, face additional risks, as the lack of nutrients impedes proper growth and development, potentially leading to permanent physical and cognitive impairments.

Marasmus: The Primary Form of Starvation-Induced Malnutrition

Marasmus is classified as non-edematous severe acute malnutrition, primarily affecting infants and young children, but it can impact any age group experiencing severe nutritional deprivation. Key features include extreme weight loss and the visible wasting away of fat and muscle, giving the affected individual a skeletal and emaciated appearance. The body is left with little to no subcutaneous fat, making bones and joints prominent. The face often appears old and wizened due to the loss of fat from the cheeks.

Common physical signs of marasmus include:

Severe weight loss, often more than 40% of normal body weight.
Apathetic or irritable behavior.
Dry, thin, and loose skin, which hangs in folds.
Visible muscle wasting and minimal subcutaneous fat.
The head may appear disproportionately large for the shrunken body.
Weakness and fatigue.

Distinguishing Marasmus from Kwashiorkor

While both are forms of protein-energy malnutrition, marasmus and kwashiorkor present with distinct clinical signs based on the nature of the dietary deficiency. Kwashiorkor, which is caused by a diet that is disproportionately low in protein but may have some caloric intake, is characterized by edema (fluid retention). This fluid retention can cause a swollen belly and extremities, masking the underlying malnutrition. In contrast, marasmus stems from a more general and severe lack of all macronutrients, meaning edema is not a primary symptom.

Comparison Table: Marasmus vs. Kwashiorkor


Feature	Marasmus	Kwashiorkor
Primary Cause	Severe overall deficiency of calories and all macronutrients, including protein.	Severe protein deficiency with relatively adequate calorie intake.
Appearance	Wasted, emaciated; skeleton prominent, loose and wrinkled skin.	Edema (swelling) in the face, limbs, and abdomen, masking wasting.
Body Fat	Near-complete loss of subcutaneous fat.	Subcutaneous fat is often preserved initially.
Muscle Wasting	Marked muscle wasting.	Less severe muscle wasting compared to marasmus.
Appetite	Often ravenous.	Poor appetite (anorexia).
Prognosis	Can be good if identified and treated early in infants.	Generally worse than marasmus; higher mortality rate.

The Severity of Starvation's Toll

Prolonged starvation, which results in marasmus, has cascading effects on all of the body's systems. Cardiovascular function is impaired, leading to a slow heart rate and low blood pressure. Respiratory rate and capacity decrease, and body temperature drops, contributing to hypothermia. The gastrointestinal tract begins to atrophy, which can ironically lead to malabsorption issues even when food is reintroduced. For children, the cognitive and intellectual development can be permanently compromised. The combination of a weakened immune system and declining organ function makes the individual vulnerable to fatal complications like sepsis and heart failure.

Conclusion

Marasmus is the quintessential form of protein-energy malnutrition caused by starvation, distinguished by severe wasting and the depletion of both fat and muscle reserves. It is a critical health condition, particularly for young children in poverty-stricken regions, and requires a cautious and staged approach to treatment to prevent life-threatening complications like refeeding syndrome. By understanding the specific impacts of complete calorie and protein deprivation, medical professionals can better diagnose and manage this devastating condition. Early intervention and consistent nutritional rehabilitation are crucial for recovery and to minimize long-term health consequences.

Frequently Asked Questions

The primary cause of marasmus is starvation, which is a severe and prolonged deficiency of all major macronutrients, including protein, carbohydrates, and fats.

The main difference is the type of nutritional deficiency. Marasmus is caused by a deficiency of all macronutrients, resulting in severe wasting. Kwashiorkor is primarily a protein deficiency, which leads to fluid retention and edema, masking the wasting.

The most common signs include severe weight loss, visible muscle and fat wasting (leaving bones prominent), and dry, wrinkled skin that hangs loosely.

The body first slows its metabolic rate and then begins to break down its own tissues—starting with fat and then muscle—to provide energy for essential organ function.

Refeeding syndrome is a dangerous metabolic shift that occurs when a severely malnourished person is fed too quickly. It can cause critical fluid and electrolyte imbalances, leading to cardiac and other systemic complications.

Yes, chronic marasmus, especially in young children, can cause stunted growth and long-term or permanent cognitive impairment, developmental delays, and a weakened immune system.

Infants and young children, particularly in areas with poverty and food scarcity, are most susceptible to marasmus. Other at-risk groups include the elderly, institutionalized individuals, and those with certain chronic illnesses.