Gluten-Free Diet Adherence and BMI z-Scores in Pediatric Celiac Disease: Distinguishing Recovery From Excess Weight Gain.

BACKGROUND

Weight changes following gluten-free diet (GFD) initiation in children with celiac disease remain debated. The diet corrects malabsorption in underweight children but may promote excessive weight gain in those diagnosed at normal weight. We examined whether weight gain on the GFD represents physiological recovery or emerging obesity risk in a Turkish pediatric cohort.

METHODS

We retrospectively analyzed 117 children diagnosed with celiac disease between 2015 and 2025. Patients were stratified by dietary adherence: strict (n = 56), partial (n = 44), and non-adherent (n = 17). Adherence was assessed via clinical symptoms, tissue transglutaminase serology, and patient interviews. Body mass index (BMI) and height-for-age z-scores were calculated at diagnosis and follow-up (minimum 12 months) per WHO 2007 Growth Reference standards.

RESULTS

BMI z-scores increased significantly only in the strict adherence group (median Δ +0.27, p = 0.036), while partial adherence (p = 0.451) and non-adherence (p = 0.579) groups showed no significant change. Between-group comparison was not significant (p = 0.326). Height-for-age z-scores showed no significant change in the strict adherence group (p = 0.247); BMI gains reflected disproportionate weight gain rather than proportional growth recovery. Six patients (5.1%) exceeded the obesity threshold (z-score > +2) during follow-up.

CONCLUSION

Weight gain occurred primarily with strict GFD adherence. Without corresponding linear growth improvement, BMI increases in strictly adherent children may not represent catch-up growth alone. Low obesity frequency may reflect traditional Turkish dietary patterns. Dietary counseling for celiac patients should extend beyond gluten avoidance to address overall nutritional balance.