Is moong dal (split green gram) low in Fermentable Oligo-, Di-, Mono-saccharides, and Polyols (FODMAPs) for individuals with Irritable Bowel Syndrome (IBS)?

Is Moong Dal Low FODMAP?

No, moong dal (split green gram/mung beans) is NOT low FODMAP and should be avoided during the elimination phase of a low FODMAP diet due to its high galacto-oligosaccharide (GOS) content.

FODMAP Content of Legumes

Moong dal belongs to the legume family, which is universally high in galacto-oligosaccharides (GOS), one of the five main FODMAP subgroups 1.

• Legumes, including beans and pulses, are explicitly listed as high-FODMAP foods that must be eliminated during the restriction phase of the low FODMAP diet 2
• GOS are found abundantly in beans and legumes, making them problematic for individuals with IBS 1
• These oligosaccharides are poorly digested in the small intestine and undergo rapid bacterial fermentation in the proximal colon, triggering symptoms of gas, bloating, abdominal pain, and altered bowel habits 1

Implementation During Low FODMAP Diet Phases

Elimination Phase (4-8 weeks)

• All legumes, including moong dal, must be completely eliminated during the initial restriction phase 3, 2
• This strict elimination is necessary to determine if symptoms are linked to FODMAP intake 3

Reintroduction Phase (6-10 weeks)

• After successful symptom control during elimination, moong dal can be systematically reintroduced as part of the GOS challenge 3, 2
• Introduce in increasing quantities over 3 days while monitoring symptom responses 2
• GOS (found in legumes) is one of the three most common FODMAP triggers, along with fructans and mannitol 2

Personalization Phase

• If moong dal is well-tolerated during reintroduction, it can be incorporated into the long-term personalized diet in tolerated portions 3
• If symptoms recur, it should remain restricted 3

Potential Processing Modifications

• Food processing techniques, particularly canning, can reduce FODMAP content in some legumes 4
• However, specific data on moong dal processing is not available in the current evidence
• Sprouting, pickling, and fermentation have shown variable effects on FODMAP reduction in plant-based foods 4

Clinical Context for Mediterranean Diet Approach

• For patients with mild gastrointestinal symptoms or those with moderate-to-severe anxiety/depression who are poor candidates for strict FODMAP restriction, a "gentle Mediterranean diet" approach may be considered 5
• This modified approach would initially incorporate only legumes that are low in FODMAPs (not moong dal) and small amounts of high-FODMAP vegetables 5
• This gentler approach has not been tested in trials but is used anecdotally in practice 5

Important Caveats

• The low FODMAP diet should be implemented under supervision of a registered dietitian with gastrointestinal expertise 3, 2
• Do not continue strict FODMAP restriction long-term (beyond 4-8 weeks) without progressing to reintroduction, as this can negatively impact the gut microbiome and reduce beneficial bifidobacteria 3, 2
• Approximately 70% of IBS patients respond to the low FODMAP diet, with 52-86% reporting significant symptom improvement 2, 6