Protein-energy malnutrition

Last updated: July 19, 2022

Summarytoggle arrow icon

Malnutrition is a significant cause of morbidity and mortality worldwide, leading to ∼ 45% of all deaths in children under the age of five. Approximately 52 million children have wasting with one-third (17 million) suffering from severe acute malnutrition. Even more children (∼ 154.8 million) have stunted growth, indicating widespread chronic malnutrition. In severe cases, primary protein-energy malnutrition (PEM) can develop, which has two major clinical forms: kwashiorkor and marasmus. Kwashiorkor is characterized by muscle atrophy, pitting edema, and distended abdomen with an enlarged fatty liver. It is caused by a deficiency of dietary protein despite sufficient calorie intake (e.g., from carbohydrates). Marasmus is the diffuse loss of muscle and fat tissue (without edema or distended abdomen) due to a severe state of total calorie deficiency of all macronutrients. Secondary PEM occurs due to illnesses affecting appetite, digestion, absorption, metabolism, and/or increased energy/protein demand. In addition to muscle atrophy, it is possible for patients to have clinical features of either marasmus or kwashiorkor. All forms of PEM are primarily clinical diagnoses; for primary PEM, WHO diagnostic criteria involve a child's weight-for-length/height and mid-upper arm circumference. Thorough laboratory testing should also be conducted to evaluate for severity and complications. Treatment involves managing complications, rehydration, and careful nutritional rehabilitation to avoid refeeding syndrome. In the case of secondary PEM, underlying conditions should also be treated, as well.

Main types of PEM
Marasmus Kwashiorkor
Deficiency
  • Primarily protein, e.g., due to:
    • Premature cessation of breastfeeding
    • Chronic GI infection
    • Protein-deficient diet: inadequate intake of staple foods without the necessary amounts of proteins (e.g., sweet potatoes, cassava)
Calorie intake
  • Deficient
  • Variable (can be normal or even high)
Pathophysiology
  • Severe energy deficiency leads to a catabolic state → breakdown of adipose tissue, muscle, and, ultimately, organ tissue for energy

Epidemiology [3][4]

  • Widespread in children living in resource-limited countries in Sub-Saharan Africa, South-East Asia, and Central America.
  • Marasmus is more common than kwashiorkor.
  • ∼ 45% of children's deaths < 5 years of age are associated with undernutrition [5]
  • Growth stunting affects 144 million children < 5 years of age worldwide.
Key clinical features

Marasmic kwashiorkor

Protein-deficient KWick MEALS lead to Kwashiorkor: Malnutrition, Edema, Anemia, fatty Liver, Skin lesions.

Marasmus causes Muscle wasting but no edema.

PEM is primarily a clinical diagnosis. Laboratory testing should be conducted to assess the severity and complications. Additional testing may be required to determine the underlying condition for secondary PEM.

Clinical diagnosis [6]

Primary PEM

Secondary PEM

Laboratory tests

Refeeding syndrome is a frequent complication if nutritional rehabilitation occurs too rapidly (sudden shift from a catabolic to an anabolic state): It is characterized by fluid retention, hypophosphatemia, hypomagnesemia, and hypokalemia.

  • Approx. 50 million children < 5 years of age are malnourished. The fatality rate of severely malnourished children brought to the hospital still is 30–50%. With the right management, this rate can be reduced to approx. 5%. The following 10 steps (conditions to treat) are an attempt to drastically reduce the fatality rate. [8]
  • The first 9 steps usually take at least 1–3 weeks depending on the child's general status and recovery. [9]
10 steps for inpatient management of severely undernourished children [8][10]
Condition to treat Phase Management Maintenance
1. Hypoglycemia
  • Stabilization: initiate immediately and continue for up to 2 days
  • Blood glucose and body temperature should be managed simultaneously
  • Blood glucose
    • When unable to test blood glucose levels, treat as if the child were hypoglycemic.
    • Test blood glucose levels.
    • Administer glucose (oral liquid glucose if child is conscious; IV glucose infusion if child is unconscious).
  • Body temperature
    • When unable to take the temperature, treat as if the child had hypothermia.
    • Take axillary (hypothermia: < 35.0 °C) or rectal (hypothermia: < 35.5 °C) temperature
    • Rewarm the child, especially the head (with e.g., clothes, blankets, heating lamp, skin to skin with the mother).
  • Monitor blood glucose level, temperature, and consciousness.
  • Feed every 2 hours, also during the night
2. Hypothermia
  • Keep the child warm; also during the night (e.g., by avoiding bathing and drafts).
  • Keep the child dry (e.g., change wet diapers).
  • Feed every 2 hours, also during the night
3. Dehydration
4. Electrolyte imbalance
  • Stabilization and rehabilitation: initiate immediately and continue for up to 6 weeks
  • Test serum electrolyte levels.
  • Rehydrate with low sodium fluid.
  • Give low sodium food.
  • Administer potassium and magnesium.
  • Monitor serum electrolyte levels.
  • Continuously administer potassium and magnesium (e.g., by adding them to the solid food).
5. Infections
  • Stabilization: initiate immediately and continue for up to 7 days
  • Reassess general condition of the child and adjust antibiotics if necessary.
6. Micronutrient deficiencies
  • Stabilization and rehabilitation: initiate immediately and continue for up to 6 weeks
  • Reassess general condition of the child and adjust supplements if necessary.
7. Cautious feeding
  • Stabilization: initiate immediately and continue for up to 7 days
  • Feed orally (if oral feeding is not possible, feed enterally via nasogastric tube).
  • Feed low-osmolarity and low-lactose foods as soon as possible (e.g., milk-based formulas).
  • Feed small portions every 2–4 hours.
  • Gradually increase feeding volume and decrease frequency (over the course of 1 week depending on the child's general status).
  • Monitor vomiting frequency and the child's weight.
  • Compensate food loss after vomiting; if oral feeding is refused, administer via nasogastric tube.
8. Catch-up growth
  • Replace milk-based formula with higher caloric food (e.g., porridge).
  • Increase portion size slowly to prevent heart failure.
  • Monitor heart rate and respiratory rate.
  • Monitor the child's weight gain daily.
  • If child fails to respond to treatment, reassess 1 to 7 and adjust management if necessary.
  • If child is breastfed, continue feeding higher caloric food AND breastfeeding (breastmilk does not contain enough sufficient calories and/or protein for rapid rehabilitation).
9. Sensory stimulation and emotional support
  • Stabilization and rehabilitation: initiate immediately and continue throughout childhood
  • Create an emotionally stable environment.
  • Provide stimulation through playtime.
  • Restart physical activity once the child is well enough.
  • Involve parents as much as possible.
10. Prepare for follow-up after recovery
  • Educate parents about correct feeding practices and playtime for the child at home.
  • Recommend regular follow-up checks to parents.

We list the most important complications. The selection is not exhaustive.

  1. Manary MJ, Leeuwenburgh C, Heinecke JW. Increased oxidative stress in kwashiorkor. J Pediatr. 2000; 137 (3): p.421-424. doi: 10.1067/mpd.2000.107512 . | Open in Read by QxMD
  2. Smith MI, Yatsunenko T, Manary MJ, et al. Gut Microbiomes of Malawian Twin Pairs Discordant for Kwashiorkor. Science (80- ). 2013; 339 (6119): p.548-554. doi: 10.1126/science.1229000 . | Open in Read by QxMD
  3. Levels and trends in child malnutrition: Key Findings of the 2020 Edition of the Joint Child Malnutrition Estimates.
  4. Manary M, Heikens G, Golden M. Viewpoint: part 3:Kwashiorkor: more hypothesis testing is needed to understand the aetiology of oedema. Malawi Medical Journal. 2009; 21 (3). doi: 10.4314/mmj.v21i3.45630 . | Open in Read by QxMD
  5. Malnutrition. https://www.who.int/news-room/fact-sheets/detail/malnutrition. Updated: June 9, 2021. Accessed: June 21, 2022.
  6. WHO guidelines for the inpatient treatment of severely malnourished children. https://apps.who.int/iris/bitstream/handle/10665/42724/9241546093.pdf. Updated: January 1, 2003. Accessed: April 4, 2022.
  7. Baraki AG, Akalu TY, Wolde HF, et al. Time to recovery from severe acute malnutrition and its predictors: a multicentre retrospective follow-up study in Amhara region, north-west Ethiopia. BMJ Open. 2020; 10 (2): p.e034583. doi: 10.1136/bmjopen-2019-034583 . | Open in Read by QxMD
  8. Ashworth A, Jackson A, Khanum S, Schofield C. Ten steps to recovery.. Child Health Dialogue. 1996 : p.10-2.
  9. Protein-Energy Undernutrition (PEU). https://www.msdmanuals.com/professional/nutritional-disorders/undernutrition/protein-energy-undernutrition-peu. Updated: January 31, 2020. Accessed: September 1, 2020.
  10. WHO child growth standards and the identification of severe acute malnutrition in infants and children. https://www.who.int/nutrition/publications/severemalnutrition/9789241598163_eng.pdf. . Accessed: September 1, 2020.
  11. Kumar V, Abbas AK, Aster JC. Robbins & Cotran Pathologic Basis of Disease. Elsevier Saunders ; 2014
  12. Kliegman R, Stanton B, St. Geme J, Schor N. Nelson Textbook of Pediatrics. Elsevier ; 2015

Access full content

Sign up and get unlimited access.
 Evidence-based content, created and peer-reviewed by physicians. Read the disclaimer