Here are some guidelines for FODMAP food challenges
Reintroducing the FODMAPs one at a time
All FODMAPs can cause IBS symptoms, and if they are eaten together, their effect is cumulative. Any meal is likely to contain a variety of foods and, therefore, a complex mixture of carbohydrates, which includes FODMAPs. The low-FODMAP diet aims to reduce the intake of all FODMAPs so that IBS symptoms are reduced as much as possible.
While all FODMAPs are potential triggers for IBS symptoms, which FODMAP has the greatest effect on you will depend on how much and how often you consume foods that contain them. In many cultures, fructose and fructans are the most widespread and frequently eaten FODMAPs. Lactose, GOS, and polyol intake can vary significantly.
Intake can also vary seasonally: Sorbitol intake is likely to be higher in summer when stone fruits are in abundance. Indian and Mexican cuisines, which are based largely on lentils and beans, will have a higher GOS content.
Once you have followed the low-FODMAP diet for two months and have seen an improvement in your symptoms, you can reintroduce the FODMAPs, one at a time, to determine which contribute to your symptoms and how much of each you can tolerate. This process is called a food challenge.
Here are some guidelines for FODMAP food challenges:
- Test only one FODMAP subgroup at a time.
- Choose an amount of food that reflects a normal portion size.
You will gain no useful information about your tolerance of a FODMAP group if you challenge yourself with a very large—or unreasonably small—intake in your trial dose. Any food consumed in excessive amounts is likely to induce symptoms.
- Where possible, choose a food that contains only one type of FODMAP, to enable a more accurate interpretation of your response.
- Continue to restrict all other FODMAPs until your tolerance (or intolerance) is confirmed.
- Maintain a consistent intake of caffeine and alcohol, or of any other foods you know are a problem for you.
- Challenge with one FODMAP per week.
- Eat the challenge food at least twice during the test week (or until symptoms are triggered).
FODMAP Challenge Printable
Although it is recommended to spend 2 months restricting all FODMAPs, most people following the diet are able to add various foods—sometimes in limited quantities—back into their diet.