Endoscopic disease activity (OR = 7.30, 95%CI 1.80–28.14), high annual healthcare utility (OR = 5.58, 95%CI 1.79–17.40), abdominal pain (OR = 3.41, 95%CI 1.03–11.27), 18.5 ≤ BMI ≤ 22 kg/m2 (OR = 9.53, 95%CI 3.20–28.37), CRP > 0.5 (OR = 9.15, 95%CI 2.39–35.05) and steroid therapy (OR = 7.23, 95%CI 1.75–29.84) were all positively associated with malnutrition development after adjustment for disease duration, age of diagnosis and MUST score (Supplementary Table S3). The gene discussed is CRP; the disease is malnutrition.