What Brings Marasmus? Exploring the Causes of Severe Malnutrition

December 30, 2025 •

4 min read

According to UNICEF, nearly half of all deaths in children under five are linked to malnutrition, with marasmus being a particularly devastating form of this condition. But what brings marasmus to a child or adult, causing extreme wasting and emaciation? The answer is a complex interplay of inadequate nutrition, underlying health issues, and socioeconomic factors that deprive the body of essential calories and nutrients.

Quick Summary

Marasmus is a severe form of malnutrition resulting from a prolonged and overall deficiency of calories and nutrients, primarily affecting infants and young children in resource-limited settings. It leads to severe muscle and fat wasting, stunted growth, and numerous systemic complications, often triggered by food insecurity, infectious diseases, and poor caregiving practices.

Key Points

Total Calorie Deficiency: Marasmus is caused by an overall lack of calories from all macronutrients, unlike kwashiorkor, which is primarily a protein deficiency.
Poverty is a Root Cause: The most significant driver of marasmus is food scarcity and poverty, especially in developing nations, compounded by poor sanitation.
Infection Creates a Vicious Cycle: A weakened immune system from malnutrition makes the body susceptible to infections, which in turn worsen malnutrition, creating a dangerous feedback loop.
Body Wasting is a Defining Symptom: The body consumes its own fat and muscle for energy, leading to the severe emaciation and stunted growth characteristic of marasmus.
Treatment Requires Careful Phasing: Medical management involves a slow, staged approach to avoid refeeding syndrome, a potentially fatal complication from a sudden increase in nutrition.
Long-Term Consequences are Severe: Untreated or prolonged marasmus can lead to permanent developmental delays, cognitive impairment, and increased susceptibility to chronic diseases later in life.
Not Just a Problem for Children: While most common in young children, marasmus can also affect adults, particularly the elderly with dementia or chronic illness, and those with eating disorders.

The Primary Nutritional Deficiencies that Bring Marasmus

Marasmus is ultimately a consequence of severe and prolonged protein-energy malnutrition (PEM), meaning the body is starved of both protein and calories over an extended period. Unlike kwashiorkor, which is a protein-specific deficiency, marasmus stems from an overall lack of all macronutrients: carbohydrates, proteins, and fats.

This nutritional deficit forces the body into a state of severe survival mode. After exhausting its stored glycogen, it begins to break down its own tissues for energy. First, it depletes the body's adipose tissue (fat), followed by muscle mass, resulting in the characteristic wasted, emaciated appearance.

Leading Social and Economic Drivers of Marasmus

While the immediate cause is nutritional deficiency, the root drivers are typically social and economic, especially in developing nations.

Poverty and food insecurity: This is the most significant factor. Families living in poverty lack the resources to access a consistent and nutrient-rich food supply. This can be exacerbated by war, natural disasters, and famine.
Lack of nutritional education: In many communities, caregivers lack proper knowledge about infant and child feeding practices. Inadequate breastfeeding or the early cessation of it can significantly increase the risk in infants. Furthermore, a misunderstanding of a balanced diet can lead to malnutrition even when some food is available.
Poor sanitation and hygiene: Unclean living conditions and contaminated water sources lead to infectious diseases like chronic diarrhea and parasites. These infections can further deplete a child's nutritional status by causing fluid and nutrient loss and reducing their appetite.
Inadequate maternal nutrition: Malnutrition in pregnant and lactating women leads to low birth weight infants who are already at a heightened risk for marasmus.

Medical Conditions that Trigger or Worsen Marasmus

Certain health issues can either cause or compound the effects of malnutrition, bringing on marasmus even when diet is not the sole factor. These conditions can interfere with nutrient absorption or increase the body's metabolic demands.

Chronic infectious diseases: Long-term infections, particularly HIV/AIDS and tuberculosis, increase the body's energy needs and suppress appetite. In pediatric AIDS, marasmus can be a severe complication in the final stages.
Gastrointestinal disorders: Conditions that impair nutrient absorption, such as celiac disease and chronic diarrhea, prevent the body from utilizing the nutrients it consumes.
Psychiatric conditions: In developed countries, eating disorders like anorexia nervosa can be a cause of marasmus. In the elderly, dementia and depression can lead to a reduced appetite and food intake.
Congenital issues: Certain conditions like congenital heart disease can increase metabolic demands and cause feeding difficulties from birth.

Comparison: Marasmus vs. Kwashiorkor

While both are forms of severe malnutrition, their presentations and underlying causes differ. This table highlights the key distinctions.


Feature	Marasmus	Kwashiorkor
Primary Deficiency	Total calorie and nutrient deficiency	Protein deficiency (with often sufficient calorie intake)
Appearance	Wasted, emaciated; prominent bones, sagging skin	Edema (swelling), especially in the abdomen and face
Body Composition	Severe muscle and fat wasting	Fluid retention masks underlying wasting; fatty liver often present
Appetite	Can be normal or even increased initially (food-seeking)	Typically poor or absent
Onset Age	Can occur in infants under one year	Often seen in children after weaning, typically over 18 months

The Vicious Cycle of Malnutrition and Infection

Marasmus is part of a dangerous feedback loop. The severe malnutrition weakens the immune system, making the body more susceptible to infections. These infections, in turn, reduce appetite, cause nutrient loss through diarrhea, and increase the body's metabolic needs, further exacerbating the malnutrition. This cycle can be lethal if not broken with comprehensive medical care.

How Marasmus Alters the Body

When the body is deprived of energy, it undergoes a series of critical, and often damaging, adaptations to survive.

Metabolic slowdown: The body reduces its metabolic rate to conserve energy, leading to low body temperature and a slow heart rate.
Atrophy of organs: Internal organs, including the heart and intestines, begin to atrophy from a lack of resources. The digestive system's atrophy can lead to malabsorption, making recovery difficult.
Hormonal changes: Levels of insulin decrease, while stress hormones like cortisol increase, promoting the breakdown of tissues for energy.
Immunodeficiency: The thymus gland atrophies, compromising the T-cell immune response and increasing vulnerability to opportunistic infections.

Conclusion: Preventing and Treating Marasmus

What brings marasmus to a population is a systemic failure of adequate nutrition and healthcare. Prevention is multifaceted and includes improving food security, promoting nutritional education, and ensuring access to clean water and healthcare. For those affected, treatment requires careful medical supervision to manage stabilization, nutritional rehabilitation, and follow-up care. By addressing the root causes of poverty and disease, we can effectively combat this life-threatening condition and secure healthier outcomes for the world's most vulnerable populations.

For more information, read the NCBI review: Recognition and Management of Marasmus and Kwashiorkor.

Frequently Asked Questions

Marasmus is characterized by severe muscle and fat wasting, leading to a thin, emaciated appearance with prominent bones. Kwashiorkor, in contrast, is defined by edema, or swelling, which can cause a distended belly and a round face despite the individual being malnourished.

Yes, marasmus can often be cured with proper nutritional rehabilitation and medical care. Treatment involves gradually reintroducing nutrients under medical supervision to avoid refeeding syndrome. With a stable, caring environment, many patients, especially children, can make a full recovery.

Yes, long-term effects of marasmus can include stunted growth, delayed cognitive and intellectual development, and a higher risk for chronic health issues like type 2 diabetes and cardiovascular disease in adulthood.

Infections cause marasmus by creating a negative feedback loop. They increase the body's energy demands while simultaneously reducing appetite and impairing nutrient absorption through issues like chronic diarrhea. This worsens the malnourished state and weakens the immune system further.

The most vulnerable populations include infants and young children in developing countries due to poverty and food scarcity. Other high-risk groups include the elderly living alone or in care facilities, and individuals with chronic illnesses or eating disorders.

While a lack of food is the most common cause globally, marasmus can also be triggered or exacerbated by other factors. These include underlying health conditions that hinder nutrient absorption, infections, psychiatric disorders like anorexia, or poor feeding practices, even if some food is available.

The body initiates a survival strategy by slowing its metabolism and breaking down its own tissues for energy, starting with fat and then muscle. This leads to cardiac, digestive, and immune system atrophy, and hormonal imbalances, impairing critical bodily functions.