Nutritional Status, Body Composition and Growth in Paediatric-Onset Ulcerative Colitis: A Systematic Review.

Background: Growth impairment and poor nutritional status are recognized complications of pediatric inflammatory bowel disease (IBD), yet data specific to ulcerative colitis (UC) are limited. This systematic review aims to provide an overview of current knowledge on growth, nutritional status, and body composition in children and adolescents with UC. Methods: A systematic literature search was performed up to August 2025. Studies including patients aged 5-22 years with confirmed UC were reviewed. Results related to growth, nutritional status, and body composition were narratively synthesized to summarize findings. Results: Fifteen studies with 1575 patients with UC met inclusion criteria, comprising 5 prospective, 5 cross-sectional, and 5 retrospective designs. Although the included studies were conducted in broader IBD cohorts, only UC-specific outcomes were reported. The data were limited by sample size, heterogeneity in patient characteristics, outcome definitions, and assessment methods. The majority of patients had prolonged disease with remission or mild activity. Growth failure prevalence ranged from 7% to 36%, with weight deficits being more common than height deficits. Undernutrition affected up to 25% of patients, with variability across studies. Overweight and obesity were also observed, though most studies showed no significant differences between UC patients and controls. Only five very small studies assessed body composition, reporting inconsistent findings regarding reductions in lean body mass. Conclusions: Growth impairment and poor nutritional status can occur in children and adolescents with UC. Larger, standardized, high-quality studies focused specifically on UC are needed to better characterize its impact on growth and nutritional status, including the essential integration of body composition assessment.