Micronutrient Intake Changes With the Low FODMAP and mNICE Diets

Abstract

Introduction: The role of the low FODMAP (fermentable oligo-, di-, mono-saccharides and polyols) diet has gained increasing acceptance for the treatment of irritable bowel syndrome (IBS) but potential safety concerns have been raised regarding nutritional adequacy. Changes in micronutrient intake with a low FODMAP diet have not been previously investigated. Daily micronutrient intake after 4 weeks of a low FODMAP diet or a modified NICE (mNICE) diet was compared to baseline. Methods: A post-hoc analysis of a single-center, randomized-controlled trial of adult patients with IBS-Diarrhea (IBS-D) was utilized which compared the efficacy of a low FODMAP and the mNICE diets on IBS symptoms over a 4-week period. The Nutrition Data System for Research (NDSR) computer program was used to analyze 3-day food diaries at baseline and at 4 weeks. Results: Data from 78 patients who completed the study were included. 41 patients were randomized to the low FODMAP diet and 37 patients were randomized to the mNICE diet. The average BMI in the low FODMAP group was 27.7 ± 6.5 compared to an average BMI of 31.4 ± 7.9 in the mNICE group (p=0.003). Both diets resulted in fewer daily kilocalories and number of daily meals consumed (Table 1). Among the patients on the low FODMAP diet, a statistically significant decrease from baseline in the daily intake retinol, thiamin, riboflavin, calcium, and trans-fatty acids was observed. There was a statistically significant increase from baseline in the intake of vitamin B6. In the mNICE group, there was a statistically significant decrease in the daily intake of polyunsaturated fatty acids only. The remaining micronutrient differences compared to baseline were not statistically significant.Table: No Caption availableConclusion: During a 4-week dietary intervention, the average daily intake of most micronutrients remained stable and within recommended dietary allowances. A low FODMAP diet was associated with a significantly lower daily intake of retinol, thiamin, riboflavin, calcium, trans-fatty acids, while the daily intake of vitamin B6 was increased. The mNICE diet was associated only with lower daily intake of polyunsaturated fatty acids. While statistically significant, the clinical significance of these findings are unclear and suggest that for a short-term elimination diet, the low FODMAP diet is not associated with major micronutrient inadequacies. These findings reinforce the importance of diversifying a patient's diet through reintroduction of foods containing FODMAPs.