Defining malnutrition: A plea to rethink.

Area of Science:

• Clinical Nutrition
• Pathophysiology
• Medical Diagnostics

Background:

• A recent consensus report proposed defining malnutrition based on low Body Mass Index (BMI) or low Fat-Free Mass Index (FFMI) and unintentional weight loss.
• This definition was endorsed by the European Society for Clinical Nutrition and Metabolism (ESPEN), despite a previously established different definition.
• The current approach is imprecise as low BMI doesn't always indicate malnutrition, and increasing BMI can coincide with decreasing Fat-Free Mass (FFM).

Purpose of the Study:

• To critique the limitations of the recent consensus definition of malnutrition.
• To propose a more comprehensive definition that incorporates key pathophysiological elements.
• To advocate for a diagnostic approach that improves the assessment and management of malnutrition.

Main Methods:

• Analysis of the proposed consensus definition for malnutrition diagnosis.
• Review of the pathophysiology of malnutrition, emphasizing the role of inflammation and nutrient balance.
• Comparison of the consensus definition with a proposed pathophysiology-informed approach.

Main Results:

• The consensus definition is imprecise, failing to account for the impact of inflammation on nutritional status.
• It does not assess functional abilities, hindering the prediction of patient outcomes and treatment effectiveness.
• Individuals with malnutrition often experience a combination of deficient nutrition and infection/inflammation, jointly affecting body composition and function.

Conclusions:

• A precise diagnosis of malnutrition requires assessing inflammation, negative nutrient balance, changes in body composition, and functional status.
• The proposed consensus definition is inadequate for accurately diagnosing malnutrition, particularly in clinical settings where inflammation is prevalent.
• An improved definition incorporating pathophysiology is crucial for effective treatment planning and outcome prediction in malnourished individuals.