Assessment of ultra-processed food consumption and pro-inflammatory dietary load in adults diagnosed with fibromyalgia syndrome: A case-control study.

Background: Fibromyalgia syndrome (FMS) is a chronic condition marked by widespread musculoskeletal pain, persistent fatigue, and cognitive impairment. Its pathophysiology involves central sensitization, neuroinflammation, oxidative stress, and gut microbiota dysbiosis. Emerging evidence suggests that dietary factors-particularly the consumption of ultra-processed foods (UPFs)-may exacerbate these mechanisms and contribute to increased symptom burden. Aims/Objectives: This study aimed to examine the dietary patterns, inflammatory potential of the diet, and body composition profiles in adults diagnosed with FMS compared to healthy controls. Methods/Methodology: A case-control study was conducted with 89 adults (45 with FMS and 44 healthy controls). Dietary intake was assessed using a validated semi-quantitative Food Frequency Questionnaire. Food items were classified using the NOVA system, and the Dietary Inflammatory Index (DII) was calculated. Anthropometric data, body composition, and clinical variables-including pain intensity (Visual Analog Scale, VAS), fatigue (Fatigue Severity Scale, FSS), and Fibromyalgia Impact Questionnaire (FIQ)-were recorded. Statistical analyses included t-tests and Mann-Whitney U tests (significance set at p < 0.05). Results/Findings: Patients with FMS consumed significantly more UPFs (34.5 ± 8.9% vs. 26.7 ± 7.1% of total energy intake; p < 0.001) and had higher DII scores (45.3 ± 8.7 vs. 35.1 ± 9.2; p < 0.001). The FMS group exhibited higher body mass index (27.5 ± 4.2 vs. 24.9 ± 3.8 kg/m²; p = 0.014), increased fat mass (34.5 ± 5.3% vs. 28.1 ± 4.7%; p = 0.011), and lower muscle mass (47.5 ± 4.8% vs. 49.3 ± 4.2%; p = 0.019). Clinically, they reported greater pain (VAS: 6.8 ± 1.9 vs. 1.2 ± 0.5; p < 0.001) and fatigue (FSS: 5.1 ± 1.1 vs. 2.4 ± 0.7; p < 0.001), with significant impairments in FIQ scores. Nutritional analysis showed lower intakes of magnesium, vitamin C, and polyphenols, and higher consumption of saturated fats and refined carbohydrates. Conclusion: Adults with FMS display a pro-inflammatory dietary profile characterized by high UPF consumption and reduced intake of protective nutrients. These patterns are associated with worsened symptomatology and adverse body composition, underscoring the potential role of anti-inflammatory dietary strategies in multidisciplinary FMS management.