How long should I do the low FODMAP diet?

The strict first step lasts two to six weeks. After that you test foods back and keep only the limits you need.

Can I do low FODMAP without a dietitian?

Many people try, but Monash recommends a dietitian who specialises in IBS, and the NHS route to one is through a GP. The testing step is where people most often go wrong alone.

Does low FODMAP help bloating?

For many people with IBS it does, which is why it is widely recommended. If you have not been diagnosed with IBS, find out what is causing the bloating first.

Should I try the low FODMAP diet?

Updated 29 October 2026

The low FODMAP diet was developed at Monash University to help with IBS symptoms. It has three steps: swap high FODMAP foods for two to six weeks, test them back one group at a time, then eat as widely as you can. It is not meant to be a long-term diet, and Monash recommends doing it with a dietitian who knows IBS.

The three steps

Swap (2 to 6 weeks)
Replace foods high in FODMAPs with lower ones. If your symptoms do not improve in that time, the diet is probably not the answer.
Test
Bring the FODMAP groups back one at a time, usually a food from one group each day for three days, and note what happens.
Your version
Keep eating everything you tolerated, and limit only what you need to. Monash calls this a personalised FODMAP diet.

This is how Monash University describes it. The third step is the point: most people end up avoiding far less than the first step asked.

Who it is for

It was designed for people with IBS. If you have not been diagnosed, see a GP first: the same symptoms can come from coeliac disease and other conditions that need a different answer. The NHS suggests a GP if diet changes have not helped or you need to avoid many foods, and they may refer you to a dietitian.

Trying something smaller first

If your symptoms are mild and you have not kept a diary, two weeks of notes can show whether the problem follows food at all, or the time you eat. Our guide on finding your bloating triggers starts there.

Where Ojafi fits

Ojafi does not put anybody on an elimination diet. If you are doing low FODMAP with a dietitian, Ojafi can be the diary: you log meals and how they sat, and it shows which of the foods you tested back actually agree with you. For the foods themselves, the Monash FODMAP app is the reference.

Questions people also ask

How long should I do the low FODMAP diet?: The strict first step lasts two to six weeks. After that you test foods back and keep only the limits you need.
Can I do low FODMAP without a dietitian?: Many people try, but Monash recommends a dietitian who specialises in IBS, and the NHS route to one is through a GP. The testing step is where people most often go wrong alone.
Does low FODMAP help bloating?: For many people with IBS it does, which is why it is widely recommended. If you have not been diagnosed with IBS, find out what is causing the bloating first.

One size fits nobody.

Ojafi starts from your tastes, your routine and how food sits with you. Free to start, no card needed.

Get started

Sources

Ojafi gives general food guidance. It is not medical advice and does not diagnose or treat any condition. See our medical disclaimer.