Are the low FODMAP serving sizes for foods per meal or per day?

Oh my friends, this is hands down one of the most frequently asked questions we get when people are starting the low FODMAP diet. So if you’ve been wondering are the low FODMAP serving sizes for foods per meal or per day, then we’ve got you covered.

First off let’s look at why serving sizes are important then we can chat about serving sizes in your meals.

 

Why are serving sizes important?

Most foods, apart from oils and proteins, will contain some level of FODMAPs – this is because FODMAPs are carbohydrates that naturally occur in fruit, vegetables, grains, legumes, dairy and processed products.

Laboratory testing is used to determine if a food contains low, moderate or high levels of FODMAPs. Often we find that a food can have different FODMAP ratings at different serving sizes.

For example, according to Monash University, sweet potato is low FODMAP at a 1/2 cup serving, moderate FODMAP in a 2/3 cup serving and high FODMAP at a 3/4 cup serving.

The above example shows that the larger the serving size of the food the more FODMAPs are present. This means that understanding portion sizes is an important part of the low FODMAP diet.

 

So, does that mean low FODMAP serving sizes for food are per meal or per day?

While you are in the first phase of the low FODMAP diet, your goal is to focus on eating low FODMAP serving sizes and foods to see if this helps you improve your gut symptoms.

The low FODMAP serving size amounts are per meal. This means you can avoid FODMAP stacking and eat the same food again after a to 3–4 hour time period (2). Leaving a few hours between each serving will help make sure that the FODMAP load from that food is spread out and keep your tummy happy.

For example, you could have a 1/2 cup serving of rolled oats for breakfast and then 3-4 hours later have 2 oat-based cookies for afternoon tea and this would still be low FODMAP.

If you want to increase your serving size of a food, make sure you check the serving size notes in the Monash University FODMAP Diet App first so you can avoid moderate and high FODMAP serving sizes until you’ve identified your personal level of tolerance.

 

Can I combine multiple foods with low FODMAP servings sizes in a meal?

Yes, the low FODMAP serving size recommendations have been developed so you can combine multiple low FODMAP serving sizes for different foods in one meal (1). We recommend that you try not to overthink your food combinations – many people find that just focusing on eating low FODMAP foods is enough to settle symptoms.

 

Where do I find serving size information for low FODMAP foods?

The best place to find serving size information for high and low FODMAP foods is in the Monash University FODMAP Diet App. This app has been developed by the lead researchers of the low FODMAP diet and has the most up-to-date and extensive lists of high and low FODMAP foods. Also, the small one off payment you make to purchase the app helps to support low FODMAP and IBS research.

You can learn more about the Monash University FODMAP Diet App here (FYI this isn’t an affiliate link, we just love their app).

We also have lots of helpful FODMAP handouts available in our FODMAP Wellness Club where you can also access FODMAP courses, dietitian-led classes, low FODMAP meal plans and more.

 

Final Thoughts

During the first phase of the low FODMAP diet focus on eating low FODMAP serving sizes and foods. Just remember that low FODMAP serving sizes for foods are per meal and not per day. This means you can repeat the same food later in the day after a 3 to 4 hour break.

 

References:

1. Monash University. Monash University Low FODMAP Diet App. 2021-Feb-17. Sourced from: https://www.monashfodmap.com/ibs-central/i-have-ibs/get-the-app/
2. Dwyer, L, McNamara & J. Varney. How to avoid FODMAP Stacking. Monash FODMAP Blog. 2019-04-17. Sourced from: https://www.monashfodmap.com/blog/how-avoid-fodmap-stacking/