Self-Reported Food Triggers and Food Fears Impact Nutrient Intake and Quality of Life in Patients with Irritable Bowel Syndrome and Functional Dyspepsia.

Background/Aims: Self-reported food triggers are common in patients with irritable bowel syndrome (IBS) and functional dyspepsia (FD), often leading to dietary restrictions which can be exacerbated by "fear of food." This study aimed to evaluate the frequency of self-reported food triggers and food-related fears in IBS and FD patients and assess their impact on nutrient intake and health-related quality of life (HRQoL). Methods: Patients meeting Rome IV criteria for IBS or FD, along with healthy controls (HCs), were enrolled. Dietary intake was assessed using a validated questionnaire; food-related fear using the 'Fear of Food Questionnaire-18', and HRQoL using the PROMIS Global-10 tool. Results: Total 811 participants (FD: 244, IBS: 160, HCs: 407; mean age: 42.3±12.3 years; males: 58.5%) were included. IBS and FD patients reported significantly more food triggers than HCs, the most frequent being spicy/fried foods in FD (50.4%) and constipation-predominant IBS (39.7%), and milk in diarrhoea-predominant IBS (70.1%). Total intake of energy, protein, fat, carbohydrates, and FODMAPs was significantly lower in IBS and FD patients compared to HCs. Food-related fear scores were significantly higher in IBS and FD patients and showed a strong correlation with both the number of food triggers and reduced nutrient intake. Food triggers negatively impacted HRQoL, both directly and indirectly, through food-related fear. Conclusions: Patients with IBS and FD report significantly more food triggers which correlates with reduced macronutrient and FODMAP intake. Food-related fear is strongly associated with diminished nutrient consumption and lower HRQoL. These findings highlight the importance of personalized psychological and dietary interventions in management of IBS and FD.