FODMAP Diet Not Linked with Micronutrient Inadequacies for IBS with Diarrhea Treatment

A comparison of the FODMAP and the mNICE diets during a 4-week dietary intervention showed that the mean daily intake of most micronutrients remained stable and within recommended allowances for both diets among patients with irritable bowel syndrome (IBS) with diarrhea, according to a study published in Journal of the Academy of Nutrition and Dietetics.

What is the FODMAP Diet

The FODMAP diet is a diet low in fermentable, oligosaccharides, disaccharides, monosaccharides, and polyols that has become commonplace in the treatment of IBS. The diet starts with a 2- to 4-week restriction phase where foods high in FODMAPS are swapped out for low-FODMAP alternatives. Later these categories of food are reintroduced one at a time.

Concerns have been raised about a diet low in FODMAPS though, and this study was designed to look at changes in the mean daily nutrient content of all meals and snacks before and after 4-weeks of a low FODMAP-diet and to identify nutritional inadequacies compared with a National Institute for Health and Care Excellence (NICE)-guided diet.

The study included 78 patients with IBS with diarrhea recruited from gastroenterology and primary care practices at the University of Michigan Medical Center from 2012 to 2015. Low FODMAP was used in 41 patients and mNICE in 37.

Overall, patients on either diet consumed fewer daily kilocalories, daily meals, and carbohydrates. Patients on the low-FODMAP diet did have a significant decrease in several micronutrients compared with patients using the mNICE cohort. After the researchers adjusted for calorie-adjusted nutrient intake, this difference in micronutrients was only significant for riboflavin.

Finally, fewer patients using the low-FODMAP diet met Dietary Reference Intakes for thiamin and iron compared with the mNICE group, but fewer patients in mNICE met requirements for calcium and copper.

FODMAP Does Not Lead to Nutrient Deficiencies

“These findings suggest that for a short-term elimination diet, the low-FODMAP diet is not associated with major micronutrient inadequacies,” the researchers wrote. “Subsequent studies will be required to better understand the reintroduction and maintenance phases of the low-FODMAP diet plan, in the case that any persistent long-term differences develop during this maintenance phase, and whether or not nutrient supplementation should be considered, especially given the baseline nutrient intake in this population.”

Eswaran S, Dolan RD, Ball SC, et al. The impact of a 4-week low-FODMAP and mNICE diet on nutrient intake in a sample of US adults with irritable bowel syndrome with diarrhea. J Acad Nutr Diet. 2019 May 15. Pii:S2212-2672(18)31544-2. Doi:10.1016/j.jand.2019.03.003.