Table 5.
Studies included to assess nutritional adequacy of the LFD
| First author, year (country) | Study design | Number of IBS subjects | Intervention | Study duration | Methodology | Results |
|---|---|---|---|---|---|---|
| Eswaran, 2019 [56] (USA) | Parallel | 78 | LFD vs. traditional IBS diet (NICE) | 4 weeks | 3-day food diary (at baseline and last week of intervention period). Post hoc analysis of [70] | Reduction in energy-adjusted carbohydrate (− 31.6 g/day), total sugar (− 17.4 g/day), sodium (− 0.5 g/day) (all P < 0.01) and riboflavin (− 0.2 mg/day) intake (P < 0.05) vs. baseline, compared to no changes in traditional IBS diet; increase in energy-adjusted niacin (0.7 mg/day, P < 0.05) and vit B6 (0.3 mg/day, P < 0.01) intake vs. baseline, compared to no changes in traditional IBS diet; fewer patients met the DRIs for thiamin and iron in the LFD group, vs. fewer patients meeting the DRIs for calcium and copper in the control group |
| O’Keeffe, 2018 [54] (UK) | Prospective follow-up study | 103 | LFD vs. habitual diet | 6–18 month follow-up after initial 6-week LFD | Semi-quantitative FFQ (at follow-up) | No statistically significant differences between groups at long-term follow-up for energy and (micro)nutrient intakes, except for higher folate (398 µg/day vs. 318 µg/day, P = 0.02) and vitamin A (2147 µg/day vs. 1429 µg/day, P = 0.045) compared to habitual diet |
| Ostgaard, 2012 [55] (Norway) | Prospective follow-up study | 114 | LFD advice vs. no advice vs. healthy controls | 2-year follow-up after LFD advice | Semi-quantitative FFQ (at follow-up) | No difference in calories or macronutrients between LFD guided patients, unguided patients and healthy controls; no difference in micronutrients between LFD guided and unguided patients; lower intakes of riboflavin (1.9 mg/day vs. 2.1 mg/day) and calcium (1065 mg/day vs. 1184 mg/day) and higher intakes of β-carotene (3.9 mg/day vs. 3.6 mg/day) and vitamin B6 (1.7 mg/day vs. 1.6 mg/day) for LFD guided patients vs. healthy controls |
| Pourmand, 2018 [51] (Iran) | Cross-sectional | 3362 (number of confirmed IBS cases NR) | Quintiles of FODMAP intake | – | 106-item semi-quantitative food frequency questionnaire | Individuals with the highest adherence to the low FODMAP diet had lower dietary intakes of all measured foods groups and (micro)nutrients (P < 0.001) |
| Staudacher, 2019 [57] (UK) | Parallel | 130 | LFD vs. habitual diet; LFD vs. sham exclusion diet | 4 weeks |
7-day food record (at baseline and last week of intervention period); diet quality according to Healthy Diet Indicator and Healthy Diet Score; Diet Diversity according to Diet Quality Index-Revised Dietary Diversity and Dietary Diversity Score |
Lower intake of starch vs. habitual control diet (109 g/day vs. 128 g/day, P = 0.03); no difference in micronutrient intakes except for higher intake of vitamin B-12 vs. habitual and sham control diets (6.1 μg/day vs. 3.9 μg/day and 4.7 μg/day respectively, P < 0.01) and higher intake of selenium vs. sham control diet (52 μg/day vs. 42 μg/day, P = 0.03); no difference in proportion of patients meeting micronutrient DRIs; overall scores for diet quality were lower after low FODMAP advice vs. habitual control diet (P < 0.01) |
| Only macronutrient data | ||||||
| Böhn, 2015 [63] (Sweden) | Parallel | 67 | LFD vs. traditional IBS diet (NICE and BDA) | 4 weeks | 4-day food diary (at screening and during last week of intervention period) | Reduced mean intake of carbohydrates (159.1 g/day vs. 193.1 g/day, P = 0.007) and dietary fiber (15.1 g vs. 20.2 g, P = 0.003) vs. traditional IBS diet |
| Zahedi, 2018 [42] (Iran) | Parallel | 101 | LFD vs. traditional IBS diet (BDA) | 6 weeks | 3-day food diary (at baseline and last week of intervention period) | Reduced mean intake of carbohydrates (266.1 g/day vs. 360.9 g/day, P < 0.001) and increased mean intake of fat (65.2 g/day vs. 51.4 g/day, P = 0.04) vs. traditional IBS diet |
BDA British Dietetic Association; DRI dietary reference intakes; FFQ food frequency questionnaire; FODMAP fermentable oligo-, di-, monosaccharides and polyols; GI gastrointestinal; IBS irritable bowel; LFD low-FODMAP diet; NICE National Institute for Health and Care Excellence; QoL quality of life