Body mass index in children with newly diagnosed celiac disease: A systematic review and meta-analysis

Clinical manifestations of celiac disease (CeD) in children are often associated with malabsorption, malnutrition, and underweight. Recent evidence suggests an increased prevalence in normal-weight and obese children. Under-recognition of patients with normal or high BMI can lead to delayed diagnosis and serious complications. The present study aimed to determine the BMI status of children with CeD at diagnosis and before gluten-free diet (GFD). A systematic review and meta-analysis was conducted following the PRISMA and MOOSE guidelines and after PROSPERO registration (CRD42023390243). The information sources, including PubMed, Scopus, and Web of Science, were systematically searched through 30 September 2025 to identify relevant articles. The study's eligibility criteria included observational studies, such as retrospective, cross-sectional, and prospective designs, with participants whose CeD diagnosis was confirmed by a gastroenterologist and who reported BMI data at the time of diagnosis. Heterogeneity among studies was assessed using the I² statistic. Funnel plots and Egger's test were also used to examine publication bias. The risk of bias of studies was assessed using the Newcastle-Ottawa (NOS) scale. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework was used to determine the certainty of the evidence. Overall, 32 studies including 14,169 children with CeD were investigated. The pooled prevalence of underweight and overweight/obesity at diagnosis was 15.3% (10.8-20.4%) and 10.5% (5.7-16.4%), respectively. Subgroup analysis by WHO region revealed a marked heterogeneity (I² > 90%), with the highest prevalence of underweight observed in the Eastern Mediterranean Region (EMRO) (31.9%). On the other hand, the highest prevalence of overweight/obesity was observed in the European Region (EURO) (12.0%) and the Western Pacific Region (WPRO) (21.4%). A key finding was a significant difference across World Bank income groups; underweight prevalence was nearly four times higher in low- and middle-income countries (LMICs), 35.48 (24.29, 47.51), compared with high-income countries, 9.58 (6.88, 12.63). The certainty of the evidence for all pooled prevalence estimates was rated as very low due to serious inconsistency and imprecision.

The prevalence of normal weight and overweight/obesity in children with celiac disease at diagnosis was higher than that of underweight, mainly in high-income countries. This finding challenges the traditional belief about the CeD and emphasizes its diagnosis in children with suspicious symptoms, regardless of their BMI status. This approach will lead to earlier diagnosis, improving clinical outcomes and quality of life for patients in the long term.

• The clinical presentation of celiac disease is evolving, and its association with underweight is inconsistent. • The structural effects of COVID-19 on the developing brain remain poorly understood due to limited pediatric imaging studies.

• This is the first meta-analysis focused exclusively on children, revealing that the majority (70.2%) present with a normal BMI at diagnosis. • The clinical inconsistency in BMI presentation is strongly linked to income levels; underweight prevalence is nearly four times higher in LMICs (35.5%) than in high-income countries (9.6%).