Psychosocial Functioning, Dietary Patterns and Socioeconomic Determinants of Quality of Life in Polish Women with Fibromyalgia: A Cross-Sectional Study

Background: Fibromyalgia is a chronic pain syndrome associated with impaired psychosocial functioning, reduced quality of life, and substantial socioeconomic burden. Although nutritional approaches to fibromyalgia management are increasingly investigated, the relationships between dietary patterns, socioeconomic determinants, and quality of life remain unclear. This study aimed to assess associations between fibromyalgia severity, psychosocial functioning, dietary patterns (DPs), socioeconomic factors, and self-rated quality of life among Polish women with fibromyalgia. Methods: A cross-sectional online survey was conducted between March and April 2026 among members of nationwide Polish Facebook support groups for individuals with fibromyalgia. The final analysis included 201 women who self-reported a physician diagnosis of fibromyalgia. Fibromyalgia severity was assessed using the Modified Fibromyalgia Assessment Status (FAS), disease impact using the Revised Fibromyalgia Impact Questionnaire (FIQR), and quality of life using selected WHOQOL-BREF domains. Dietary patterns were identified using principal component analysis (PCA) based on the frequency of consumption of 33 food groups from the KomPAN questionnaire. Hierarchical linear regression models were applied to identify predictors of self-rated quality of life. Results: Four dietary patterns were identified: traditional, meat-and-fat, pro-healthy, and dairy-based. Participants reported low overall quality of life and moderate fibromyalgia severity. A better self-rated financial situation was associated with a higher quality of life only in the initial regression model (β = 0.325; p < 0.001). After adjustment for clinical and psychosocial variables, socioeconomic factors and dietary patterns were no longer significant predictors. Functional limitations (FIQR Functioning: β = −0.202; p = 0.022) and overall disease impact (FIQR Overall Impact: β = −0.189; p = 0.026) were negatively associated with quality of life, whereas psychological (β = 0.234; p < 0.001) and social functioning (β = 0.162; p = 0.023) were positive predictors. The final model explained 40.3% of the variance in quality of life. Conclusions: These findings support a comprehensive biopsychosocial model of fibromyalgia care.