Reliability of a Food Frequency Questionnaire in the Assessment of Dietary Intake Including FODMAPs in Different Populations, and Relationship With IBS Symptoms and the Degree of Self-assessed Physical Activity

Inclusion criteria

• 18 - 65 years;
• Provide written informed consent;
• Living in Belgium

Exclusion criteria

• Diet < 8 weeks prior to participation;
• Known or suspected eating disorder;
• Major psychiatric disorder;
• Known gastro-intestinal disease (IBS is allowed);
• Any malignancy in the past 3 years (basocellular carcinoma is allowed);
• Chemotherapy in the past 6 months;
• Infectious gastro-enteritis in the past 6 months (infectious gastro-enteritis defined as the concurrent presence of one of the following signs during 2 or more consecutive days: fever, vomiting, sudden onset of diarrhea, hospitalization because of these symptoms);
• Previous abdominal surgery (appendectomy and cholecystectomy are allowed);
• Alcohol abuse defined as > 14 U per week;
• Use of illicit drugs;
• Intake of drugs with known major gastro-intestinal side effects.
• Initiation of neuromodulators less than 3 months before participation. Neuromodulators are allowed when taken at a stable dose for at least 3 months;
• Pregnancy.