Protein-Energy Malnutrition (PEM) | Marasmus and Kwashiorkor

According to WHO protein-energy malnutrition (PEM) refers to “an imbalance between the supply of protein and energy and the body’s demand for them to ensure optimal growth and function”.

PEM is classified into two types:

  • Primary PEM
  • Secondary PEM

Primary PEM

Primary PEM is a type of protein-energy malnutrition that is found in children in the initial few years after birth. In children, PEM is primarily of two types:
(a) Kwashiorkor
(b) Marasmus

Dietary deficiency of proteins and total food calories results in malnutrition which is widespread in many underdeveloped countries of South-East Asia, South America, West, and Central Africa. The effect of malnutrition is more prominent in children than in adults.

Protein-energy malnutrition (PEM) may affect large sections of the population during drought, famine, political turmoil, chaos, disorder, disturbance, and mess. A case study from Bangladesh during the liberation war and in Ethiopia during the severe drought in the mid-’80s. PEM affects infants and children resulting in Marasmus and Kwashiorkor.

It has been observed that in both Kwashiorkor and Marasmus, physical and mental development is affected, emerging in serious illness and severe health issues.


Marasmus is produced by a simultaneous deficiency of proteins and calories. It occurs in infants having an age of less than a year if the mother’s milk is replaced too early by other foods that are poor in both proteins and calorific value.

This often happens if the mother has second pregnancy or childbirth when the older infant is still too young. In marasmus, protein deficiency impairs the growth and replacement of tissue proteins, extreme emaciation of the body, and thinning of limbs occurs; the skin becomes dry, thin, and wrinkled.

Growth rate and body weight decline considerably, The growth and development of the brain and mental faculties are also impaired.

Symptoms of marasmus

  • Children become weak and get fatigued easily
  • Depressed eye
  • Old man’s face
  • Wasted muscles
  • Very little fat
  • Prominent ribs
  • Very underweight
  • No subcutaneous fat
  • Severely emaciated (abnormally thin)


Bulging eye symptom of Kwashiorkor | Protein-energy malnutrition
Bulging eye symptom of Kwashiorkor

Kwashiorkor is also known as edematous malnutrition in medical terms. It generally happens in the child having more than one year old.

Kwashiorkor is produced by protein deficiency unaccompanied by calorie deficiency. It results from the early replacement of the mother’s milk by a high-calorie and low-protein diet in a child.

Like marasmus, kwashiorkor shows wasting of muscles, thinning of limbs, failure of body growth, and brain development. But unlike marasmus, some fat is still left moreover, extensive edema and swelling of body parts are seen.

In this condition, extensive edema can be observed. Subcutaneous fat is still present below the surface of the skin. Wasting of muscles and thinking of limbs also occur in children having Kwashiorkor. Muscle wasting decreases body strength and the ability to move. Skin appears to be swollen and children remain underweight in this disease.

Symptoms of kwashiorkor

  • Retarted mental and physical growth
  • Loss of appetite
  • Bulging eye
  • Protruding bellies
  • The skin becomes dry, lusterless, and appearance of black spots
  • Hair feels dry, textureless, lusterless and may turn reddish yellow to white in color which results in sparse, brittle, and can be pulled out easily
  • Nail plates are thin and soft, fissured, or ridged
  • Wasted muscles can be observed which means a weakening, shrinking, and loss of muscle
  • Enlarged liver with fatty infiltrates
  • Fat present beneath the subcutaneous layer of skin
  • Underweight
  • Edema (Swelling caused by excess fluid trapped in your body’s tissues) of ankles, feet, and belly
  • Children become lazy and irritated

Difference between marasmus and kwashiorkor

1.Occurs in a child below one year of ageOccurs in a child more than one year of age
2.Deficiency of protein and calories bothDeficiency of protein only
3.Skin is dry and wrinkledSkin appears swollen
4.Subcutaneous fat disappearSubcutaneous fat is still present
5.Extreme emaciation of the body and thinning of limbs occursWarring of muscles and thinning of limbs occur
6.No edemaExtreme edema observed
7.Severely emaciatedUnderweight children
8.Children become weak and get fatigued easilyChildren become lazy and irritated
Protein Energy Malnutrition (PEM)

Secondary PEM

It is caused due to disorders of the gastrointestinal tract (GIT). It may also be caused due to infections, hyperthyroidism, trauma, burns, and other critical illnesses. Secondary PEM decreases the appetite and impairs nutrient metabolism.


  1. Poverty and food insecurity: In many countries, poverty and food insecurity are the main causes of PEM. People living in poverty often have limited access to a variety of nutritious foods, and this can lead to an inadequate diet that does not meet their nutritional needs.
  2. Poor sanitation and hygiene: Poor sanitation and hygiene can also lead to PEM, as contaminated food and water can cause infections that can further impair the absorption of essential nutrients.
  3. Unhealthy lifestyle: An unhealthy lifestyle can also contribute to PEM. Not getting enough physical activity, smoking, and consuming too much alcohol can all lead to inadequate nutrition.
  4. Certain medical conditions and illnesses: Certain medical conditions and illnesses can also contribute to PEM. For instance, digestive disorders like celiac disease, Crohn’s disease, and irritable bowel syndrome can interfere with the absorption of essential nutrients.


  1. Impaired immune system: Malnutrition can lead to a weakened immune system, making people more vulnerable to illnesses and infections.
  2. Stunted growth: Malnutrition can delay the physical and mental development of children.
  3. Anemia: Malnutrition can cause anemia, a deficiency of iron that can result in fatigue and lack of energy.
  4. Delayed development: Malnutrition can cause delays in children’s physical, mental, and emotional development.
  5. Increased risk of chronic diseases: Malnutrition increases the risk of chronic conditions, such as diabetes and heart disease.
  6. Cognitive impairment: Malnutrition can lead to impaired cognitive functioning and memory problems.
  7. Organ failure: Malnutrition can lead to organ failures, such as liver and kidney failure.
  8. Death: Malnutrition can lead to death in severe cases.


The pathophysiology of PEM involves several interrelated processes. First, inadequate dietary intake leads to an imbalance of essential nutrients in the body, resulting in a depletion of cellular energy stores. This leads to decreased activity of metabolic enzymes, resulting in decreased energy production and increased fatigue.

Additionally, inadequate dietary intake leads to decreased absorption of essential nutrients, resulting in a decrease in the utilization of proteins, fats, and carbohydrates. This causes a decrease in the production of essential hormones, enzymes, and other proteins, leading to a further decrease in energy production. Finally, inadequate dietary intake leads to decreased immune system function, leading to increased susceptibility to infection.


  1. Dietary Therapy: The primary treatment for PEM is dietary therapy. Eating a balanced diet with adequate calories, proteins, and other essential nutrients is essential to reversing the effects of PEM. Foods such as lean meats, fish, eggs, legumes, nuts, and seeds are excellent sources of protein and should be included in the diet. Fruits, vegetables, and whole grains are also important sources of nutrients.
  2. Nutritional Supplements: For individuals with more severe cases of PEM, nutritional supplements may be necessary to help restore nutrient levels. These supplements may include high-protein drinks, meal replacement shakes, or vitamin and mineral supplements.
  3. Medications: In some cases, medications may be prescribed to treat underlying conditions that contribute to PEM. These medications may include antibiotics to treat infections or steroids to reduce inflammation.
  4. Intravenous Feeding: In severe cases of malnutrition, intravenous (IV) feeding may be necessary. IV feeding supplies the body with a balanced mixture of nutrients, including proteins, carbohydrates, fats, vitamins, minerals, and electrolytes. This type of therapy is typically used in a hospital setting.


The prognosis of Protein-energy malnutrition (PEM) depends on the severity of the condition and the response of the patient to treatment. If treated promptly and adequately, most patients can make a full recovery with no long-term complications.

If left untreated, or if the treatment is inadequate, PEM can lead to long-term health problems, such as stunted growth, impaired cognitive development, and increased risk of infection and other diseases.


What is Protein-energy malnutrition (PEM)?

Protein-energy malnutrition (PEM) is a condition caused by an inadequate intake of calories and protein, leading to a decrease in muscle mass, a weakened immune system, imbalances in the body’s ability to function normally, and other health problems. It is most common in developing countries, but can also occur in developed countries due to poor diet, poverty, and lack of access to adequate nutrition.

What are the symptoms of PEM?

Symptoms of PEM include thinning hair, reduced muscle mass, fatigue, poor growth, and a weakened immune system. In severe cases, it can also lead to organ failure, stunted growth, and even death.

How is PEM treated?

Treatment for PEM usually involves an increased intake of calories and protein, combined with increased physical activity, if possible. Other treatments may include nutritional supplements, vitamin and mineral supplements, and other medications as appropriate.

What are the long-term effects of PEM?

Long-term effects of PEM can include stunted growth, organ failure, weakened immune system, and other health problems. It is also important to note that if PEM is not treated, it can lead to death.

What are the causes of Protein-energy malnutrition (PEM)?

Common causes of PEM include poor dietary intake, chronic infection, inadequate access to healthcare, and poor sanitation.

What are the symptoms of Protein-energy malnutrition (PEM)?

Symptoms of PEM can range from mild to severe and include weight loss, weakness, fatigue, poor appetite, irritability, impaired immunity, and anemia.

What are the health complications associated with Protein-energy malnutrition (PEM)?

Health complications associated with PEM can include organ failure, growth and development delay, cognitive impairment, stunted growth, and increased risk of infection.

What nutritional interventions can be used to help treat Protein-energy malnutrition (PEM)?

Nutritional interventions used to help treat PEM can include dietary supplementation, fortified foods, food fortification, and nutritional counseling.

How can Protein-energy malnutrition (PEM) be prevented?

PEM can be prevented by eating a balanced diet, getting enough physical activity, and regularly visiting a doctor for check-ups.

Are there any medications that can be used to treat Protein-energy malnutrition (PEM)?

Medications used to treat PEM can include vitamins and minerals, zinc, and iron supplements.

What is the prognosis for individuals with Protein-energy malnutrition (PEM)?

The prognosis for individuals with PEM is generally good with proper treatment. Early diagnosis and intervention are key to improving the outcome.

What is the difference between Protein-energy malnutrition (PEM) and Marasmus?

PEM is a general term used to describe any form of malnutrition that results from inadequate intake of protein and energy. Marasmus is a specific form of PEM where the body has an extreme lack of both protein and energy.

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