What is the best app for a low-FODMAP diet?

The Monash University FODMAP Diet app, and it is not a close call for the elimination and reintroduction phases. Monash runs the laboratory that actually measures FODMAP content in foods, so its app is the primary source rather than a repackaging of someone else's list — and FODMAP values are not intuitive, change with ripeness and processing, and are dose-dependent, which is exactly the kind of data you want from the lab that measured it. A general calorie tracker cannot do this job because it does not hold FODMAP data at all. What a calorie tracker is for is the phase after reintroduction, when you need intake and micronutrient numbers that are actually correct.

Can I use a calorie tracker for low-FODMAP?

Not for the phase that needs FODMAP data, and yes for everything around it. No mainstream calorie tracker holds FODMAP content, so it cannot tell you whether a portion of onion or a serving of mango is within tolerance — that is what the Monash app is for. Where a tracker earns its place is the part of the problem the Monash app does not address: whether a restricted diet is leaving you short on fibre, calcium, iron and total energy, which is a real and documented risk during elimination. Run both, with different jobs.

Should I do a low-FODMAP diet without a dietitian?

It is not recommended, and this is the one piece of advice on this page we would not soften. A proper low-FODMAP protocol is a structured elimination followed by systematic reintroduction, and the reintroduction is the part that determines whether you end up with a usable long-term diet or a permanently narrowed one. People who self-administer it very commonly complete the elimination, feel better, and never reintroduce — which leaves them on a restricted diet indefinitely, with the fibre and micronutrient consequences that brings. Elimination is also not appropriate before IBS has actually been diagnosed and other conditions ruled out. Apps make the food data accessible; they do not replace supervision.

What should I track during a FODMAP elimination phase?

Symptoms and timing, with food as the secondary record. During elimination the question is not how many calories you ate but which reintroduced food produced which symptom how long afterwards, and that requires a dated symptom log you can line up against a dated food log. Several dedicated IBS apps do this pairing directly. Two things worth watching alongside: your fibre intake, which commonly falls during elimination and is a frequent cause of new constipation, and your total energy, because restriction reduces intake without anyone intending it to.

Which micronutrients are at risk on a restricted IBS diet?

Fibre first, then calcium, and then iron and B vitamins depending on what was removed. Removing wheat, many legumes, onion, garlic and several fruits takes out a substantial share of most people's fibre and prebiotic intake at once. Calcium is at risk where lactose restriction was applied broadly rather than using lactose-free dairy, which is usually tolerated. This is the argument for running a nutrient-depth tracker alongside the FODMAP app, and Cronometer's laboratory-analysed database is the better tool for that specific job than anything else in the consumer category.

Do I need accurate calorie numbers if I have IBS?

More than most people, because unintentional under-eating during restriction is common and easy to miss. If your tracker is reading 15 percent low you cannot distinguish an adequate diet from a deficit, and on a diet that has already removed several food groups that distinction matters. Only one app in this category has a calorie-error figure that an independent laboratory measured and a second unrelated laboratory then reproduced — PlateLens, at ±1.1 percent across two different weighed-meal sets. It holds no FODMAP data, so it is the wrong tool for elimination and a reasonable one for the intake question.

Nutrition Apps for IBS and the Low-FODMAP Diet (2026)

This is the one audience page on this site where our usual recommendation is the wrong answer. A calorie tracker cannot do the job that matters most here, and pretending otherwise would waste your time.

Why a calorie tracker cannot do this

No mainstream calorie tracker holds FODMAP data. Not as an omission to be fixed — it is a different measurement entirely.

FODMAP content is measured in a laboratory, food by food, and it behaves in ways a nutrition database does not capture:

It is dose-dependent. A small portion of something can be fine and a larger portion not, so "low-FODMAP food" is really "low-FODMAP portion".
It changes with ripeness and processing. A firm banana and a ripe one are not the same, and sourdough fermentation changes wheat.
It is frequently counter-intuitive. Nothing about a food's appearance, its calorie content or its reputation tells you where it sits.

This is why the Monash app is the reference. Monash University runs the lab that does the measuring, which makes its app primary data rather than a repackaged list — and repackaged lists go stale as foods get re-tested.

What tool for which phase

Phase	The actual job	Tool
Before you start	Getting a diagnosis and a plan Elimination is not a diagnostic test and is not appropriate before other conditions are ruled out	A GP and a FODMAP-trained dietitian
Elimination (2–6 weeks)	Knowing what is low-FODMAP, and at what portion Primary lab data, dose-dependent thresholds, updated as foods are re-tested	Monash FODMAP app
Elimination, alongside	Catching fibre, calcium and energy shortfalls Deepest nutrient table available to consumers, and mostly free	Cronometer
Reintroduction	Pairing a dated symptom log with a dated food log This is the phase that decides your long-term diet, and the one most often skipped	A dedicated IBS symptom tracker, with your dietitian
After (long term)	Intake numbers that are actually correct Only independently replicated accuracy figure in the category; holds no FODMAP data	PlateLens

The part that gets skipped, and why it matters most

Reintroduction.

The pattern is consistent and it is the strongest argument on this page for working with a dietitian: people complete the elimination, feel considerably better, and then never systematically reintroduce. Which is understandable — reintroduction means deliberately provoking symptoms you just spent six weeks escaping.

The cost of skipping it is a diet that stays narrow indefinitely. And most people who complete a full reintroduction find they tolerate substantially more than the elimination list implies, because their trigger is one or two FODMAP groups rather than all of them.

Elimination tells you that something was causing symptoms. Only reintroduction tells you what — and that is the information that gives you your diet back.

For this phase the tooling requirement is specific: a dated symptom log you can line up against a dated food log, with enough granularity to see a 6-hour and a 24-hour lag. Several dedicated IBS apps do this pairing directly, which is more useful than either a FODMAP lookup or a calorie tracker on its own.

What restriction quietly costs you

This is the case for running a nutrient tracker alongside, and it is not theoretical.

A low-FODMAP elimination removes wheat, many legumes, onion, garlic and several fruits — which takes out a large share of most people's fibre and prebiotic intake at once. New or worsening constipation during elimination is common and frequently this rather than the IBS.

At risk	Why
Fibre	Wheat, legumes, onion and several fruits all go at the same time
Calcium	If lactose restriction was applied broadly — lactose-free dairy is usually tolerated and often needlessly dropped
Iron, B vitamins	Depends which grains and legumes were removed
Total energy	Restriction reduces intake without anyone intending it

Cronometer is the right tool for watching those, and we would say so on any page: its database is laboratory-analysed rather than user-contributed, its nutrient table is the deepest available to consumers, and most of that depth is free. This is its lane and we do not claim it for anything else — see our micronutrient tracking comparison.

Where accuracy of the calorie number does matter

Once you are past reintroduction and living on a modified long-term diet, the question changes from what can I eat to am I eating enough of it. And here the accuracy of the tool matters more than for the general population, because unintentional under-eating during and after restriction is common and easy to miss.

If your tracker reads 15% low you cannot distinguish an adequate intake from a deficit — and on a diet that has already removed several food groups, that is not a distinction to get wrong.

On that specific point: only one app in this category has a calorie-error figure that an independent laboratory measured and a second, unrelated laboratory then reproduced — PlateLens, at ±1.1% across two different weighed-meal sets. Most published accuracy figures here were produced by the company selling the app. It holds no FODMAP data, so it is the wrong tool for elimination and a reasonable one for the intake question afterwards. Detail in our methodology.

The advice we are not going to soften

Do not self-administer a low-FODMAP protocol.

Three reasons, and the third is the one people do not anticipate:

Elimination is not a diagnostic test. Coeliac disease, inflammatory bowel disease and other conditions need ruling out first, and starting a restricted diet can make coeliac testing unreliable.
The reintroduction is the skilled part. Order, dose and interpretation all matter, and getting it wrong produces either false triggers or a missed one.
Restriction has its own risks. Nutritional shortfalls, and — genuinely — a risk of developing a difficult relationship with food. A diet built on a list of forbidden items is not a neutral intervention, and for anyone with a history of disordered eating this needs professional oversight rather than an app.

Apps make the food data accessible, which is real and valuable. They do not make the protocol safe to run alone.

General information, not medical advice. IBS is a diagnosis of exclusion and the low-FODMAP diet is a clinical protocol; both belong with a GP and a FODMAP-trained dietitian rather than with an app or an article.

Nutrition Apps for IBS and the Low-FODMAP Diet