What you need to know about FODMAP Stacking
When you’re on a low FODMAP diet and trying to avoid triggering your IBS symptoms, you get very familiar with what foods contain what FODMAPs and what is considered a “safe” serving size. But what if you are sticking to safe servings sizes and you’re still having symptoms? This may be the result of FODMAP stacking.
What is FODMAP stacking? When you have multiple “safe” servings of different foods containing the same FODMAP, or multiple servings of foods containing different FODMAPs and the combined effect causes you distress, this is what we refer to as FODMAP stacking.
Important note: There is no need to worry about FODMAP stacking if your symptoms are well controlled. If, however, you’re still having symptoms while following a low FODMAP diet, then FODMAP stacking may be a contributing factor. Read on.
This article is adapted from this post by Monash University
Are FODMAP amounts cumulative?
The short answer is, yes. In one sitting, the total amount of FODMAPs consumed (be it from fructose, fructans, lactose, GOS, or polyols) influences whether the meal is tolerated or whether symptoms are induced.
The Monash University FODMAP diet app uses a traffic light system to indicate the rating of each FODMAP in individual foods (fructose, sorbitol, mannitol, lactose, fructans, and GOS), and the overall FODMAP rating (low (green), medium (yellow), high (red)) of foods at different serving sizes. But we know that people don’t just eat individual foods, they eat mixed meals including multiple different foods. For this reason, the Monash recommendations for low FODMAP serving sizes were set conservatively, allowing people to include more than one green light serving of food per sitting.
Everyone’s threshold level of FODMAP tolerance is different. While FODMAP stacking will be relevant to some people who may find they experience IBS symptoms when multiple green light servings are eaten in one sitting, for many, the conservative FODMAP serving sizes set by Monash means they will achieve good symptom control even when consuming a varied diet that includes numerous green light servings at each sitting.
Does FODMAP stacking relate to the foods eaten over a whole day or just in one meal?
As a general rule, the concept of stacking relates to a single sitting or meal. This of course assumes that meals are spaced out over the day, with at least 2-3 hours between each meal or snack. This allows food to be digested between meals and slows the rate at which the gut is exposed to the FODMAPs. If you find you are constantly snacking and experiencing IBS symptoms, then spacing out your meals may help.
Do I need to track what FODMAPs I eat to avoid stacking?
First of all, if your symptoms are well controlled and you haven’t been thinking about FODMAP stacking, then don’t start worrying about it now! It doesn’t apply to you and the low FODMAP diet is working for you just fine.
You only need to consider FODMAP stacking if you notice that a low FODMAP diet has improved most of your symptoms, but not all of them.
For some people, it will be factors other than FODMAPs that are affecting their IBS symptoms such as stress, hydration, exercise, or anxiety. For others, it might be a higher sensitivity to FODMAPs and thus a need to consider FODMAP stacking as a possible trigger. If you think this applies to you, keeping a food and symptom diary is the best way to work out what your individual IBS triggers are, and whether FODMAP stacking is an issue for you.
Key Tips and Takeaways to Avoid Consequences:
Space out your meals. Leave at least 2-3 hours between eating or drinking anything other than black coffee or water (that includes meals, snacks, and beverages) to avoid potential stacking effects.
Avoid snacking. If you find you are getting hungry between meals (and I’m referring to actual hunger, not boredom, stress, or emotional eating) make sure your meals include enough protein, fat, and fiber to fill you up and keep you satisfied until the next meal.
If you must have a snack, choose a snack that is low in FODMAPs and high in food value such as a protein food (eggs/meat/fish/nuts/nut butter), a complex carbohydrate (whole grain such as whole grain sourdough bread or brown rice), or plants such as carrots or cucumbers.
What does that look like? How about a hard-boiled egg and some black olives? Or a brown rice cake with a slice or two of turkey and some sliced cucumbers on it? Or, a slice of whole grain sourdough with peanut butter on it. Or, a small handful of mixed nuts such as macadamia, pecans, almonds, etc. More snack ideas can be found on my blog here.