A narrative review of nutrition assessment in Crohn’s disease using anthropometric, biochemical and dietary indices.

Malnutrition is common in patients with Crohn’s disease and negatively impacts immunity and quality of life. The optimal tools for nutrition assessment in patients with Crohn’s disease are not clearly defined and lead to variations in practice. This review aims to appraise the existing evidence for nutrition assessment of patients with Crohn’s disease compared with healthy controls and provide a comprehensive guide with relevant measures applicable to clinical practice. A literature search using Medline, Embase and Scopus from inception to 1st October 2018 was conducted. Forty-one papers which assessed body composition, muscle strength, micronutrient status and/or dietary intake in adults with Crohn’s disease compared with an age and sex-matched healthy population were included. There were heterogeneous findings on nutrition status in Crohn’s disease compared with healthy controls. Only one paper reported a clinically significant difference for BMI; however significant deficits in fat mass, fat-free mass and muscle strength were observed in Crohn’s disease compared with healthy controls, with more pronounced differences with increasing disease activity and length of diagnosis. Most research reported significantly lower serum micronutrients in Crohn’s disease compared with healthy controls. Half of studies measuring micronutrient intake reported lower intakes in Crohn’s disease compared with healthy controls. Fruit and vegetable intake was also lower in Crohn’s disease. Difficulties characterising the type and prevalence of malnutrition exist due to the heterogeneous nature of Crohn’s disease and warrants continued investigation. This review advocates that a nutrition assessment should include more parameters than weight and body mass index.