Comparison of gastrointestinal symptom burden, dietary habits, and quality of life between women with Hashimoto’s thyroiditis and healthy controls: a cross-sectional study

Aims: To compare nutrition-related behaviors, gastrointestinal (GI) symptoms, food insecurity, and health-related quality of life between women with Hashimoto thyroiditis (HT) and healthy controls, and to explore factors associated with HT. Methods: In this case-control study conducted in Adana, Turkiye, 214 adult women (107 HT; 107 controls) completed a face-to-face questionnaire including a nutrition habits survey, the Mediterranean Diet Adherence Screener (MEDAS), the Food Insecurity Experience Scale (FIES), the Gastrointestinal Symptom Rating Scale (GSRS), and the Short Form-36 (SF-36). Group comparisons used chi-square and Mann-Whitney U tests, correlations were assessed with Spearman’s rho, logistic regression explored factors associated with HT, and path analysis examined interrelationships among food insecurity, MEDAS, GSRS, and SF-36. Results: Compared with controls, the HT group had lower Mediterranean diet adherence (median MEDAS 7 vs 8; p=0.023), higher constipation and reflux symptom scores (p=0.006 and p=0.023), and lower mental health scores (SF-36 mental health; p<0.001). In univariable analysis, higher MEDAS was inversely associated with HT (OR=0.834; p=0.005). In multivariable analysis, regular exercise remained inversely associated with HT (OR≈0.38; p=0.012). Higher GI symptom burden was associated with lower SF-36 scores (β≈-4.11 per unit; p<0.001). Food insecurity did not differ significantly between groups. Conclusion: HT was associated with poorer GI symptom profiles and lower Mediterranean diet adherence. These findings suggest that care for women with HT may benefit from attention to dietary pattern quality, individualized dietary counseling, routine GI symptom assessment, and support for regular physical activity.