Protein energy malnutrition – Classification, causes and symptoms

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Protein energy malnutrition (PEM) is the term given to a group of clinical conditions which occur due to inadequate protein and calorie intake, especially in children.

Protein energy malnutrition – Classification, causes and symptomsIt is a grave problem in developing countries as pregnant mothers do not get enough nutrition and healthy food, which puts the baby at a disadvantage even before he/she is born.

Classification of protein energy malnutrition

Protein energy malnutrition has been classified in many ways, two of the important types are mentioned below.

Clinical classification

  • Kwashiorkar
  • Marasmus
  • Marasmic Kwashiorkar

Gomez classification

Grade 1- 90-75% of expected weight

Grade 2 – 75-60% of expected weight

Grade 3 - <60% of expected weight

Causes of protein energy malnutrition

  • When PEM is purely due to dietary deficiency, it is termed as the primary type. This begins at the foetal stage and continues into infancy and childhood. Nearly 25% of the paediatric hospital beds in India are occupied by children suffering from malnutrition and around 80% of hospitalised children are malnourished to some extent. Hence this contributes to the infant mortality ratio in a big way.
  • Secondary malnutrition arises due to a serious illness like tuberculosis, cancer or inability of the body to absorb nutrients for e.g. in bowel disease like ulcerative colitis, metabolic syndromes and long standing gastro-enteritis.
  • Dietary factors contributing to PEM are inadequate breast feeding by the mother due to inability of mother’s body to make milk due to inadequate nutrition, stopping breastfeeding early in case of working mothers and inadequate supplementation of other foods, ignorance of weaning and weaning foods, inverted or cracked nipples in mother causing difficulty in breastfeeding. Another important reason is nipple confusion when the baby is switched from breast to the artificial nipple and bottle. Formula milk may not be well tolerated leading to diarrhoea.
  • Problems in the mother such as mental or psychiatric illnesses, post-natal depression (severe cases), poor maternal health like anaemia and having too many children in quick succession or having twins may lead to the mother producing not enough milk to meet the demand of the infants.
  • Traditional methods which are harmful to the baby may be practised in villages and rural areas such as not offering colostrum (the fluid that comes out of the nipple in the first few hours after delivery) which is very healthy and boosts the baby’s immune system and withholding breast milk when the baby has diarrhoea. Even in remote areas, health professions should conduct antenatal classes for mothers-to-be and educated them.
  • All kinds of infections in the baby such as oral ulcers, gastroenteritis, food poisoning, diarrhoea and serious conditions such as congenital heart or kidney disease may cause inability to suckle which causes malnutrition. Thus, infection and malnutrition is a vicious cycle as one contributes to the other.
  • Low socioeconomic status of the people coupled with the desire to have more children (especially boys) is the social malady that many uneducated people suffer from.


Kwashiorkar comes from an African word meaning `displaced child’ referring to the illness of the older infant who is denied breast milk when the new baby is born. Kwashiorkar is common in children between one and five years. It is due to a protein deficiency which occurs after protein rich foods are discontinued during weaning and the child is given food low in proteins and calories.

Symptoms of kwashiorkar

  • Children appear smaller than their age
  • Skin is pale, dry and flaky, hair turns reddish
  • Muscles are limp and underdeveloped
  • Children frequently have digestive problems
  • Fluid retention in the body causes a distended abdomen, swollen hands and ankles. This is called oedema
  • Very thin limbs, liver may be enlarged
  • Children lack enthusiasm and look unhappy


This condition is generally seen in infants less than one year old. It occurs due to a deficiency of proteins, carbohydrates and fats. Marasmus is the childhood equivalent of starvation in adults and is more serious than Kwashiorkar.

Symptoms of marasmus

  • A large face over a shrunken body
  • Eyes are sunken, cheeks are hollow giving a prematurely aged look
  • Oedema is absent, abdomen is curved inwards
  • Skin is dry, loose and wrinkled due to loss of fat below the skin
  • Hair may be normal or dry, thin and light coloured.
  • Muscles are wasted and have poor tone
  • Bones are prominent due to absence of fat around them

Marasmic Kwashiorkar

This includes symptoms of both Marasmus and Kwashiorkar and represents the gravest form of PEM.

Photograph via

Written by Dr Nisreen Nakhoda, General Physician

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