Articles on: Interpreting your results

High scores most evenings? Transit time & FODMAP stacking explained!

If you've just started your breath testing journey with FoodMarble and you've noticed that your results trend upwards over the course of the day, most days, here are two important factors to consider when reviewing and interpreting your results:

Gastric Transit Time

Gastric transit time is the time it takes for ingested material to journey through your digestive system. Gastric transit times vary a lot from person to person, so the following information should act as a guide:

Ingested material can reach the small intestine within 1-2 hours and reach the colon within 3-8 hours.

Gastric transit times may vary depending on the foods consumed and may also be affected by stress, sleep quality, exercise, medications taken and so on. This is why we recommend logging all of these within the FoodMarble app.

FODMAP Stacking

FODMAPs in your foods are cumulative, meaning they stack. Even if you are following the low FODMAP diet, you still have to be mindful when eating, as quantity and portion size are very important considerations.

FODMAP stacking occurs when the FODMAPs in your food add up and push you over your threshold. A food that you ate for breakfast may be fine on its own, but when combined with other FODMAP-containing foods in your lunch and dinner, the cumulative effect means they can add up to become a problem over the course of the day.

This helps to explain why it's not always the most recent meal eaten on its own that has caused your fermentation levels to rise. Instead, the stacking effect may be causing your results to spike later in the day.


If you've noticed a trend in your results where your scores are generally low during the day, but begin to rise into the evening or at nighttime, consider both your gastric transit time and if the FODMAP stacking effect is having an impact on your digestion.

Updated on: 20/11/2023

Was this article helpful?

Share your feedback


Thank you!