Bioelectrical impedance vector analysis in patients with irritable bowel syndrome on a low FODMAP diet: a pilot study

Background: The aim of this study was to determine the effects of a low fermentable oligo-, di- and monosaccharides and polyols (FODMAP) diet on the nutritional status and body composition, abdominal symptoms, quality of life, anxiety/depression and sleep quality of patients with irritable bowel syndrome (IBS). Methods: Consecutive patients were given a low FODMAP diet for 8 weeks. At baseline and after 8 weeks, blood tests were taken to evaluate nutritional status and a bioelectrical impedance analysis was performed to assess body composition. Anthropometric data, IBS Symptom Severity Score, results of a bowel habits questionnaire, Bristol Stool Chart classification, SF36, Hamilton Depression Anxiety Scale outcome and Pittsburgh Sleep Quality Index were also recorded. During the 8-week diet period, the patients were phoned periodically by the nutritionist to verify their compliance. Results: Twenty-six IBS patients with a mean age of 46.2 ± 13.8 years were studied. After 8 weeks, there were no abnormalities in anthropometric data, bioelectrical impedance parameters and blood tests. The patients’ IBS Symptom Severity Score improved (305.2 ± 84.1 vs 156.3 ± 106.4; p < 0.0001), as did bowel habits, Bristol Stool Chart classification, quality of life and HADS anxiety score, whereas sleeping quality and depression were unchanged. The degree of relief from symptoms and satisfaction with the diet was high. Conclusions: A low FODMAP diet improved IBS symptoms without effects on nutritional status and body composition.