What is the definition of Protein-Calorie Malnutrition (PCM)?

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From the Guidelines

Protein-Calorie Malnutrition (PCM) is a condition characterized by a lack of adequate protein and calories to meet the body's nutritional needs, and can be defined by phenotypical criteria such as non-volitional weight loss, low body mass index (BMI), and reduced muscle mass, as well as etiological criteria including reduced food intake or assimilation, inflammation, or disease burden. According to the most recent and highest quality study 1, the definition of malnutrition includes these phenotypical and etiological criteria. The study highlights that in surgical patients, sarcopenic obesity may not be underestimated, and "severe" nutritional risk has been defined according to the ESPEN working group as the presence of at least one of the following criteria: weight loss >10-15% within six months, BMI <18.5 kg/m2, SGA Grade C or NRS >5, or serum albumin <30 g/l.

Key features of PCM include:

  • Non-volitional weight loss
  • Low body mass index (BMI)
  • Reduced muscle mass
  • Reduced food intake or assimilation
  • Inflammation or disease burden These parameters reflect undernutrition as well as disease-associated catabolism, and hypoalbuminemia is a clear surgical risk factor, although it reflects disease-associated catabolism and disease severity rather than undernutrition 1.

The diagnosis of PCM involves clinical assessment, anthropometric measurements, and laboratory tests showing low serum proteins. Treatment involves careful refeeding with appropriate protein and calorie supplementation, correction of electrolyte imbalances, and addressing any underlying conditions. It is essential to note that PCM can occur in various populations, including hospitalized patients, the elderly, and those with chronic diseases in developed nations, as well as in developing countries due to food insecurity 1.

In terms of management, nutritional therapy is crucial, and patients with PCM should undergo a structured dietary assessment, preferably by a dietician, to determine the best course of treatment. The therapy may involve refeeding by moderate hyperalimentation, with small meals evenly distributed throughout the day and a late-night snack, as well as avoidance of fasting 1. Additionally, the use of a multivitamin is generally recommended, although there are no firm data on the benefits of vitamin and mineral supplementation.

Overall, the definition and management of PCM should prioritize a comprehensive approach, considering both phenotypical and etiological criteria, as well as individual patient needs and underlying conditions.

From the Research

Definition of Protein-Calorie Malnutrition (PCM)

  • Protein-calorie malnutrition is defined as deficient intake or uptake of protein and energy that leads to physiologic alterations such as inflammation, loss in fat-free mass, and/or decreased response to medical treatment 2.
  • It is a specific type of malnutrition characterized by an imbalance of nutrition, including lack of adequate calories, protein, and/or other nutrients required for body functioning 2.
  • PCM can result from depleted body protein stores due to semistarvation, and its effects can be exacerbated by injury or illness 3.
  • The condition is also known as protein-energy malnutrition (PEM), and its central feature is often oedema, although other factors can also contribute to its development 4.

Key Characteristics of PCM

  • Deficient intake or uptake of protein and energy 2.
  • Physiologic alterations such as inflammation, loss in fat-free mass, and/or decreased response to medical treatment 2.
  • Depleted body protein stores due to semistarvation 3.
  • Oedema as a central feature, although other factors can also contribute to its development 4.

Diagnosis and Assessment of PCM

  • Currently, no single test can be used as a reliable indicator of malnutrition, but a combination of several tests can be used as prognostic indicators 5.
  • Body-composition analyses and functional tests hold promise for greater applicability in the future 5.
  • Anthropometric parameters, such as body mass index (BMI), can be used to assess chronic malnutrition in adults 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Protein-energy malnutrition: the nature and extent of the problem.

Clinical nutrition (Edinburgh, Scotland), 1997

Research

Assessment of protein-calorie malnutrition.

Clinical chemistry, 1984

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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