FODMAP Diet Beginner’s Guide

The FODMAP Diet is temporary learning diet designed to help alleviate digestive symptoms in those who suffer from Irritable Bowel Syndrome (IBS).

The word “FODMAP” is an acronym that represents categories of short-chain carbohydrates known to cause digestive issues like gas, bloating, diarrhea, constipation, and stomach pain in certain individuals.

Fermentable
Oligo-saccharides
Di-saccharides
Mono-saccharides
And
Polyols.

Most Common FODMAPs

Within the FODMAP acronym categories, there are a few common culprits.

FODMAPCommon Food Examples
Fructans (Oligo-)Wheat, barley, rye, garlic, onion
Galactans (Oligo-)Large portions of lentils and chickpeas, soy beans,  pinto beans, and pistachios
Lactose (Di-)Milk, yogurt, ice cream, and other milk products
Fructose (Mono-)Mango, figs, honey, high fructose corn syrup, and some vegetables
PolyolsXylitol, sorbitol, mannitol and other sugar alcohols, stone fruit, and avocado

Further Reading
Complete list of FODMAP foods
Top 45 FODMAP Ingredients

3 Phases of the FODMAP Diet

After starting the diet, you will move through each of the 3 phases.

Phase 1: Low FODMAP Diet (2-6 weeks)
The goal of this phase is to identify any high FODMAP foods in your existing diet and make low FODMAP swaps. Common swaps include:

  • Milk –> Lactose-free milk
  • Apple –> Orange
  • Wheat bread –> Sourdough

Phase 2: Reintroduction (6-8 weeks)
The goal of this phase is to identify your triggers by reintroducing each FODMAP category back into your diet one by one. Here is an example of what this might look like:

  • Week 1: Fructose – honey
  • Week 2: Lactose – milk
  • Week 3-4: Fructans – wheat, garlic
  • Week 5: Galactans – beans
  • Week 6: Polyols – avocado (sorbitol)

Phase 3: Personalization
After identifying your triggers, the goal of this final phase is to adopt a long-term FODMAP diet plan that suits you. This means avoiding foods that caused digestive issues during the reintroductions phase and continuing to reintroduce foods from categories that are well tolerated.

We highly recommend working with a FODMAP-trained dietitian to help you plan and execute each phase.

FODMAP Diet Impact on IBS & Other Health Issues

Research suggests that ~75% of IBS patients benefit from adopting the FODMAP Diet. Most patients notice a steep decline in digestive issues like bloating, gas, diarrhea, and stomach pain (1) (2).

In addition to IBS, some evidence suggests that the FODMAP Diet can help patients with overlapping IBS symptoms and Irritable Bowel Diseases (IBD) like Crohn’s disease and ulcerative colitis (3).

If you suffer from IBS or IBD and have just started the FODMAP Diet, we highly recommend joining our Facebook Support Group in addition to downloading the Spoonful and Monash Apps.