Mundane, yet challenging: the assessment of malnutrition in inflammatory bowel disease.

Protein-energy malnutrition (PEM) is defined as a "state of nutrition in which a deficiency or excess (or imbalance) of energy, protein, and other nutrients causes measurable adverse effects on tissue/body form (body shape, size and composition) and function, and clinical outcome". Although this definition resulted from a long discussion among experts, it lacks concise assessment criteria. Essential to an effective practice of nutrition support, however, is the ability to identify who actually needs medical nutrition therapy. Patients with active inflammatory bowel disease (IBD) are a high risk group for protein-energy malnutrition, with a prevalence ranging up to 75%.