Written by Emmanuel and updated on November 21, 2025. Reviewed and approved by Anne-Charlotte Jalhay, dietitian specializing in digestive disorders and the low-FODMAP diet.
“Stacking” happens when:
- two low-FODMAP foods contain the same type(s) of FODMAPs
- and you eat them in the same meal
π Each food on its own is “low”. But their combined amounts can cross the threshold and make the whole meal high in FODMAPs.
A simple example:
- No issue with carrots (very low) + eggs (zero FODMAPs).
- But if you already eat 65 g of strawberries, you’re at the fructose limit. Adding another food that also contains excess fructose can tip you over.
On the other hand, you can freely combine foods from other FODMAP families (fructans, GOS, etc.) as long as you stay within each threshold.
This logic applies per meal.
If at lunch you eat canned green peas (close to the GOS limit) plus almonds (also high in GOS), you risk exceeding the GOS threshold. But you can perfectly eat those foods again at dinner.
You’re making me laugh — come on, give me a better idea to illustrate this concept! I’m waiting. π
Photo by Markus Spiske on Unsplash
Stacking is all about quantities
As a general rule, avoid combining several foods from the same FODMAP family if you aren’t following portion sizes precisely.
Can you “flirt” with the limits?
Yes — completely. In practice, most people do, and it works very well.
For example, being close to the fructan limit at lunch and again at dinner is not an issue.
What matters is leaving 3 to 4 hours between meals so the counters “reset”.
Just be careful with snacks too close to meals.
And if you go slightly over?
According to Monash researchers, most people tolerate:
- a moderate portion, even if the low portion is exceeded
- or even a small high-FODMAP portion in some cases
The real triggers for symptoms tend to be very high-FODMAP foods (onions, some legumes, etc.).
So: don’t panic if you go over a limit from time to time — it doesn’t cancel your efforts.
If your symptoms are already well-managed and you’ve never thought about stacking before, there’s nothing alarming. Understanding stacking is simply an extra tool to help you reduce the last remaining digestive issues.
Hidden stackings you don’t expect
Stacking often comes from combinations people don’t suspect.
One Fodmapedia Premium user realised her symptoms persisted simply because every morning she drank a large black tea with melon.
Consumed together, the two exceeded the fructan threshold — and she had never made the connection.
So remember to consider the whole meal: fruits, vegetables, drinks, sauces, cold cuts… not only the “obvious” pairs or fruit-fruit combinations.
The lactose exception (otherwise it would be too easy)
Stacking applies to all FODMAP families (GOS, fructans, mannitol, sorbitol, fructose) except lactose.
Why?
Because lactose isn’t handled the same way.
Digesting it requires the enzyme lactase — and people with lactose intolerance don’t produce enough. The lactose therefore reaches the intestine almost intact, where it ferments.
As a result, the recommended limit during phases 1 and 2 isn’t based on stacking but on physiology: around 1 g of lactose per meal.
This doesn’t “stack” between foods; it simply reflects the body’s capacity to produce lactase.
For all other FODMAP families, since the issue is not enzymatic, the logic is cumulative.
Key takeaways
- Two low-FODMAP foods can push a meal into high territory if they share the same FODMAP family.
- If you don’t weigh portions, avoid combining foods that are already moderate or high in the same family.
- Leave 3 to 4 hours between meals so levels reset.
- You can flirt with the limits across different families in the same meal — it actually improves food diversity and supports the microbiota.
- Always check levels and recommended portions in Fodmapedia.
Sources
- Source 1 : FODMAP stacking – can I overeat βgreenβ foods?? – Monash University blog
- Source 2 : How to avoid FODMAP stacking – Monash University blog
