Nutritional safety and status following a 12‐week strict low FODMAP diet in patients with irritable bowel syndrome

Background A low FODMAP diet (LFD) is an established dietary treatment for patients with irritable bowel syndrome (IBS). However, knowledge on the extended effects of the restriction phase regarding nutrient intake, symptom severity, and quality of life (QoL) is sparse. Therefore, our objectives were to evaluate the safety of a dietitian‐led 12‐week strict LFD on measures of blood biochemistry, nutritional status, symptom severity, and QoL. Methods In this open‐label dietitian‐led 12‐week strict LFD intervention for IBS patients with predominantly diarrhea or mixed stool pattern (IBS‐D/−M), we collected data on diet intake (3‐day dietary record), overnight fasting routine blood samples, body weight, IBS symptoms (IBS Severity Scoring System (IBS‐SSS)), and IBS‐related QoL (IBS‐QoL) at baseline and after 12 weeks. Key Results Thirty‐six participants completed the 12‐week follow‐up (mean age: 37 years, 67% women, IBS‐SSS: 242 (101)). All blood parameters measured were within established reference values at both time points. We found no change in intake of macro‐ or micronutrients, but several micronutrients were below the recommendations both before and after 12 weeks. BMI slightly decreased, primarily driven by participants with BMI >25 (p