Understanding Protein Energy Malnutrition: Types, Causes, and Treatment

Across pediatric wards and rural health centres, a quiet crisis continues to play out: children who look far younger than their age, mothers who never quite recover their strength after pregnancy, and elderly people whose bodies simply lack the fuel to heal. The medical name for this cluster of conditions is Protein Energy Malnutrition, or PEM. It is one of the most pressing public health concerns in the developing world, and despite decades of policy attention, it still claims lives and futures every single day. Understanding what PEM is, how it shows up, why it happens, and what can be done about it is the first step toward changing that story.

What is Protein Energy Malnutrition? 🔗

The World Health Organization describes PEM as an imbalance between the supply of protein and energy and the body’s demand for them to ensure optimal growth and function. In simpler terms, it is what happens when the food a person eats does not provide enough calories, enough protein, or both, over a sustained period. The body, denied its building blocks and fuel, begins to break down its own tissues to survive.

PEM affects every age group, but its impact is most devastating in children under five, pregnant and lactating women, and elderly adults. In India, the burden is particularly heavy. According to data published in the Journal of Family Medicine and Primary Care, the prevalence of stunting among under-fives is around 48%, wasting is close to 20%, and underweight prevalence stands at roughly 43% – among the highest figures globally. The more recent NFHS-5 (2019-2021) survey continues to show that 32.1% of children under five are stunted and 19.3% are wasted, signalling that progress has been slow and uneven.

PEM is measured using three core indicators: underweight (low weight for age), stunting (low height for age, reflecting chronic malnutrition), and wasting (low weight for height, reflecting acute malnutrition). Each tells a slightly different story about how long deprivation has lasted and how severe it currently is.

The three faces of PEM 🔗

PEM is not a single disease. It presents in distinct clinical forms, each with its own appearance, biology, and prognosis. The three most recognized forms are Kwashiorkor, Marasmus, and Marasmic Kwashiorkor.

Kwashiorkor 🔗

Kwashiorkor is primarily a protein deficiency disorder, even when calorie intake from carbohydrates may be roughly adequate. The word itself comes from a West African language and historically described the illness a first child develops when displaced from the breast by a newborn sibling. It usually appears in children between one and five years of age, often during or shortly after weaning.

The clinical picture is unmistakable. The Cleveland Clinic notes that kwashiorkor is marked by edema, particularly in the ankles and feet, a bloated abdomen with fluid accumulation, dry brittle hair, hair loss, and loss of skin pigmentation. Children may also show a characteristic “moon face,” apathy, irritability, and an enlarged fatty liver. Behind the swelling lies a biochemical story: low protein intake causes hypoalbuminemia, which reduces the blood’s ability to hold fluid inside vessels, so fluid leaks into the tissues.

What makes kwashiorkor especially deceptive is that the child may not appear underweight at first glance. The fluid retained in the body masks the muscle and fat loss happening underneath, which sometimes delays diagnosis until the condition has advanced.

Marasmus 🔗

Marasmus is the result of severe deficiency of both calories and protein – essentially, starvation. It typically affects infants under one year of age and produces the haunting “wasted away” appearance that gave the condition its Greek-derived name. Marasmus involves a deficiency of all macronutrients, leaving the child shriveled, with visible ribs, sunken cheeks, and an aged, monkey-like face.

There is no edema in marasmus. Instead, there is extreme growth retardation, almost complete loss of subcutaneous fat, severe muscle wasting, and a head that looks disproportionately large compared to the rest of the body. The child is often alert but irritable, with thin sparse hair, dry loose skin, and a weak, feeble cry. Clinical literature classifies marasmus as a form of non-edematous severe acute malnutrition characterized by wasting due to prolonged deficiency in energy intake.

Marasmic Kwashiorkor 🔗

Marasmic Kwashiorkor is the most severe form of PEM, combining features of both conditions. The child shows the extreme wasting of marasmus along with the edema and skin changes of kwashiorkor. In children with marasmic kwashiorkor, body weight is typically less than 60% of the standard weight for age, and immediate medical treatment becomes essential. As the condition advances, recovery becomes progressively harder and the chances of survival drop sharply.

What causes PEM? 🔗

PEM is rarely the result of a single failure. It is the end-point of a long chain of biological, social, and economic factors that interact and reinforce one another.

Low birth weight and poor maternal nutrition 🔗

The story often begins before birth. When a pregnant woman is undernourished, anaemic, or too young, her baby is more likely to be born with a low birth weight. These infants start life with reduced reserves and immature organ systems, which makes them more vulnerable to infection and growth failure. Poor maternal nutrition is therefore not just a women’s health issue – it is the first link in the chain of childhood PEM.

Inadequate or interrupted breastfeeding 🔗

Exclusive breastfeeding for the first six months provides the perfect mix of nutrients, antibodies, and energy. When breastfeeding is stopped too early – sometimes because of the birth of another child, sometimes because of cultural beliefs or maternal employment – the infant loses both nutritional support and immune protection. Bottle-fed infants in low-income settings often receive over-diluted formula or unhygienic feeds, dramatically increasing the risk of malnutrition and diarrhoea.

Delayed or poor complementary feeding 🔗

From six months onward, breast milk alone is no longer enough. Children need semi-solid foods rich in protein, energy, and micronutrients. In many Indian households, complementary feeding is delayed, restricted to thin gruels low in nutrients, or offered too infrequently. The National Institute of Public Cooperation and Child Development highlights that misconceptions, food fallacies, poor child-rearing practices, and improper distribution of food within the family all contribute meaningfully to PEM.

Repeated infections 🔗

Infection and malnutrition feed each other in a vicious cycle. Diarrhoea, pneumonia, measles, tuberculosis, and intestinal worms all increase the body’s nutrient needs while reducing appetite and impairing absorption. A malnourished child is more likely to catch these infections, and each infection deepens the malnutrition. Poor sanitation, contaminated drinking water, and crowded living conditions amplify this risk substantially.

Low socioeconomic status 🔗

Poverty sits behind almost every other cause. Families that cannot afford diverse, protein-rich diets are forced to rely on cheap, starch-heavy staples. Add to this low parental literacy, lack of awareness about nutrition, gender bias in food distribution, and limited access to health services, and the risk multiplies. Severe acute malnutrition is closely linked to food insecurity, conflict, and inadequate health infrastructure.

Treatment of PEM 🔗

Treating PEM is not as simple as offering a hungry child a big meal. Severely malnourished children have profoundly altered metabolism, and aggressive refeeding can actually be fatal – a phenomenon known as refeeding syndrome. The World Health Organization has developed a structured 10-step protocol used in hospitals and Nutrition Rehabilitation Centres (NRCs) across India.

Stabilisation phase 🔗

The first 24 to 48 hours focus on saving life rather than rebuilding the body. Clinicians treat or prevent hypoglycaemia, hypothermia, and dehydration, correct electrolyte imbalances, and begin treating any infection. Rehydration in severely malnourished children uses special low-sodium, high-potassium solutions such as ReSoMal, since standard ORS can dangerously overload a depleted heart. Antibiotics are usually given even when no obvious infection is visible, because immune function is so suppressed.

Cautious nutritional rehabilitation 🔗

Feeding begins slowly with low-protein, low-lactose formulas such as F-75, given in small frequent feeds. Once the child is stable and the appetite returns, the team transitions to F-100 or Ready-to-Use Therapeutic Food (RUTF), which is calorie- and protein-dense and supports rapid catch-up growth. Micronutrient supplementation – including zinc, vitamin A, folate, and iron – is added in a specific sequence; iron is delayed until the recovery phase because giving it too early can worsen infections.

Follow-up and community linkage 🔗

Recovery does not end at discharge. Children need sustained follow-up to prevent relapse, along with family counselling on feeding practices, hygiene, and immunisation. Programs such as Anganwadi Services, the Integrated Child Development Services (ICDS), and the National Nutrition Mission play a key role in linking discharged children back to the community for ongoing care.

Prevention: where the real victory lies 🔗

Because PEM is rooted in social conditions, prevention requires action well beyond hospitals. Several strategies have proven effective when combined.

Promoting maternal and infant nutrition 🔗

Improving the diets of adolescent girls and pregnant women breaks the intergenerational cycle of malnutrition. Iron-folic acid supplementation, antenatal care, and education on dietary diversity all reduce the risk of low birth weight. Exclusive breastfeeding for the first six months, followed by timely and adequate complementary feeding, remains the single most powerful protective measure against childhood PEM.

Government programmes and policy 🔗

India’s flagship nutrition programme, POSHAN Abhiyaan, was launched in 2018 with the goal of reducing stunting, undernutrition, anaemia, and low birth weight through a convergent, technology-driven approach. It uses real-time monitoring through the Poshan Tracker app, social and behavioural change communication, and multi-ministerial convergence to create a people’s movement around nutrition. Alongside it, the Mid-Day Meal Scheme, Public Distribution System, and Janani Suraksha Yojana provide complementary support.

Infection control and sanitation 🔗

Because infections drive so much malnutrition, clean drinking water, sanitation, hand hygiene, and full immunisation are nutrition interventions in disguise. Deworming programmes and oral rehydration salts for diarrhoea management reduce the nutrient losses that push borderline children into severe malnutrition.

Community education 🔗

Lasting change comes from changed practices at home. Anganwadi workers, ASHAs, self-help groups, and school teachers all play a role in spreading practical knowledge: how to prepare protein-rich, low-cost recipes from locally available foods like pulses, millets, eggs, groundnuts, and green leafy vegetables; how to recognise early signs of malnutrition; and how to seek help quickly.

Why PEM still matters 🔗

Even when PEM does not kill, it leaves long shadows. Children who survive severe malnutrition often face permanent stunting, reduced cognitive ability, weaker immunity, and lower earning capacity as adults. The economic cost to a nation is enormous, and the human cost – measured in lost potential – is incalculable. Reducing PEM is not just a medical task; it is a development imperative that requires food security, women’s empowerment, sanitation, healthcare, and education to move forward together.

What do you think? If you had to choose one intervention to prioritise for ending childhood PEM in your district – better antenatal care, improved sanitation, more nutritious school meals, or stronger community awareness – which would create the largest ripple effect, and why do you think the others might not be enough on their own?

References

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC4005205/
2. https://journals.lww.com/jfmpc/fulltext/2014/03010/protein_energy_malnutrition_in_india__the_plight.15.aspx
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC12705002/
4. https://my.clevelandclinic.org/health/diseases/23099-kwashiorkor
5. https://my.clevelandclinic.org/health/diseases/23296-marasmus
6. https://www.ncbi.nlm.nih.gov/books/NBK559224/
7. https://www.medicalnewstoday.com/articles/313185
8. https://www.nipccd.nic.in/file/elearn/faq/fq22.pdf
9. https://mitaksharaacademy.com/protein-energy-malnutrition/
10. https://spmiasacademy.com/poshan-abhiyaan-scheme-and-its-importance/