The primary objective of this study is to compare the BIA parameters, including Phase Angle, Fat Free Mass and Fat Mass, between women with functional dyspepsia and healthy women. All woman will undergo a bio-electrical impedance monitoring for this.

Inclusion Criteria:

• Women aged 18 - 75 years
• Fulfilling the ROME IV criteria for functional dyspepsia (for FD patients)
• FD unexplained by upper GI endoscopy during the past 12 months (mild gastritis allowed) (for FD patients).

Exclusion Criteria:

• Clinical suspicion of an organic disorder different from FD (patients can be included when this disorder had been excluded);
• Abnormality on upper GI endoscopy other than mild gastritis (for FD patients).
• Known reflux oesophagitis Los Angeles grade C or D, known Barrett oesophagus, peptic stricture.
• H pylori infection, unless treated at least 6 months before;
• Known inflammatory bowel disorder;
• Known major intestinal motility disorder;
• Alcohol (defined as more than 14 U per week) or other substance abuse;
• Active psychiatric disorder;
• Known systemic or auto-immune disorder with implication for the GI system;
• Prior abdominal surgery (with the exception of cholecystectomy or ap-pendectomy);
• Any prior diagnosis of cancer other than basocellular carcinoma;
• Current chemotherapy;
• History of gastro-enteritis in the past 12 weeks;
• Dietary supplements unless taken at a stable dose for more than 12 weeks;
• Treatment with neuromodulators (one neuromodulator taken at a sta-ble dose for more than 12 weeks is allowed);
• Treatment with PPI's during the past 8 weeks
• Pregnancy.

female patients with or without FD between 18 and 75 years