All About Tomatoes & FODMAPs
Ketchup, tomato sauce, crushed tomatoes, tomato purée and paste – these are common pantry items and along with fresh tomatoes they can fit into a low-FODMAP diet, but we have to take heed with serving sizes.
Let’s Talk Fresh Tomatoes
Monash has tested cherry tomatoes, common beefsteak tomatoes and Roma plum tomatoes. They state approved Green Light serving sizes are as follows (updated 8/2019):
- Cherry Tomatoes – 5 cherry tomatoes at 75 g
- Common Beefsteak Tomato – 1 small tomato at 119 g, but know that NO FODMAPs were detected in lab tests.
- Roma (plum) Tomato – 1 small Roma plum tomato, which is 75 g
Does this make sense? Here’s the deal. The tomatoes that Monash tested were particular tomatoes, at a particular level of ripeness, grown in a particular place and harvested at a particular time. As with any agricultural item, lab results could be very different with a different lab sample.
We extrapolate and suggest you try up to 119 g of any kind of \fresh tomatoes and see how you do.
Note that some folks find tomatoes very acidic and their digestion is triggered negatively, but this is not a FODMAP issue.
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A Note On Ripeness
Please take note that the tomatoes that Monash has tested were ripe tomatoes. As of now they have not tested green, unripe tomatoes, so we do not know the FODMAP level of those. We have seen very different FODMAP levels in ripe and unripe produce, going both ways, so we cannot extrapolate about green tomatoes.
If you have cherry tomatoes at hand, try our Sautéed Baby Heirloom Tomatoes.
How About Prepared Tomato Products?
We have listed below the presently tested Monash tomato products – but we have some extrapolations to make here, too. There have been several tomato sauce products certified by Monash, such as FODY Marinara Sauce and Tomato and Basil Pasta Sauces, for instance.
All of these have been approved in 125 g amounts, which equals a generous ½ cup. We can therefore surmise that tomato sauces can be tolerated, if prepared correctly and taking care not to include high FODMAP ingredients, such as onion and garlic.
Several RDNs have reported that their patients do very well with Rao’s Sensitive Formula Marinara Sauce, which can be ordered by the case! We have actually never seen it in the stores, so you might have to order it. It is also lower in sodium.
In terms of tomato products, Monash has tested:
Canned Tomatoes (⅗ cup; 92 g allowed)
Ketchup (scant tablespoon; 13 g allowed; not that this is for both sucrose sweetened and ketchup that contains high fructose corn syrup)
Sun-dried tomatoes (3 pieces; 8 g allowed)
Tomato Paste (2 Australian tablespoons; 28 g allowed)
Tomato Sauce: caveat – Monash shows a ketchup bottle as the image next to this entry, which is because this is the term used for what some countries call “ketchup”. It states that 13 g or a scant tablespoon is allowed, which aligns with the “ketchup” entry.
We know from their certification program of low FODMAP pasta sauces that up to 125 g or ½ cup is allowed.
For our purposes we have made some extrapolations in regards to the “canned tomatoes” that Monash has tested and have made some educated comments below on tomato sauce, diced tomatoes, crushed tomatoes, tomato purée, etc.
Keep it Clean
Brands vary with additional ingredient content as well; some products might be flavored with basil, jalapeno, garlic or “Italian herbs” and while this can be a time saving measure for some cooks, we suggest that you purchase unadulterated tomato products for the best low-FODMAP cooking approach.
A Fruit By Any Other Name
While we all treat tomatoes as a vegetable, they are in fact a fruit (even though you will find them listed with the veggies in the Monash University app) and they contain a fair amount of fructose, which can be problematic for some of us. Now, if you are in the Elimination Phase of things, you have to be more conservative. If you have gone through the Challenge Phase and know that fructose and you get a long pretty well you can eat more liberally.
Here Is Our Guide to Buying Prepared Tomato Products
When it comes to servings sizes, use your Monash app to help guide you. Here are some things to watch out for when buying tomatoes and tomato products:
Many contain high fructose corn syrup as well as onion. Some natural brands, such as Annie’s, rely on cane sugar for sweetening, but still include onion.
Luckily, Monash has tested ketchup and even with onion and/or high fructose corn syrup the condiment is allowed and tolerated in small amounts. The app recommends “1 sachet”, which they specify as 13 g. This is the equivalent of a little more than 2 U.S. teaspoons (1 U.S. tablespoon is 17 g).
So dip your fries, just don’t slather it on. And, by the way, if you would rather not have high fructose corn syrup, try Simply Heinz.
We were shocked when we looked at labels of tomato sauce; not marinara and spaghetti sauce but plain old cans of “tomato sauce”. Who knew they often contained garlic and onion?
We like and recommend Nature’s Promise Tomato Sauce, which contains organic tomato purée, sea salt, organic sugar, organic red pepper and naturally derived citric acid or Whole Foods 365 Everyday Value Organic Tomato Sauce, which contains organic tomato purée, sea salt, organic sugar, organic red pepper and citric acid and we always have Pomi Tomato Sauce in the Test Kitchen, which has one ingredient- tomatoes! See the full entry on Pomi.
Within the Monash app you can find that ½ cup (120 ml; 92 g) of “canned tomatoes” is an acceptable amount. The low-FODMAP tolerance tips at 180g, which is just shy of ¾ cup (180 ml), so stay we suggest that you stay below that amount.
Brands like Muir Glen have a very clean label and contain tomato purée (water, organic tomato paste) and citric acid; brands with a similar label would be a good choice.
Whole Peeled Tomatoes
Again look for very clean, simple ingredient labels such as 365 Everyday Value brand from Whole Foods: tomatoes, tomato juice, salt, calcium chloride and citric acid.
Diced or Petite Diced Tomatoes
It should be easy to find a good low-FODMAP choice such as Whole Foods 365 Everyday Value Organic. Label should look like this: tomatoes, organic tomato juice, sea salt, calcium chloride and citric acid.
These terms are used interchangeably by various brands but all refer to a fairly liquid sauce that has some texture. Consider this texture more chunky than tomato sauce but less chunky than diced tomatoes.
Looks for labels with a nice short list of ingredients such as Contadina’s Crushed Tomatoes: tomato purée, crushed unpeeled tomatoes, water, salt, citric acid, calcium chloride.
Contadina Tomato Paste has one ingredient on the label – tomatoes! If you want organic, look for Whole Foods 365 Everyday Value Tomato Paste, which contains organic tomatoes and citric acid. Either would be a good option or look for similar label listings.
Sundried Tomatoes (Semi, per Monash terminology)
Processing of ingredients can change their FODMAP profiles. Think about how you can eat 1 cup (150 g) of grapes but just 1 Australian tablespoon (13 g) of raisins, for instance (this is almost 1 ½ tablespoons U.S.). Same goes for tomatoes. When they are dried the fructose concentrates.
That said, Monash has tested sun-dried tomatoes and 3 pieces (8 g) are within low-FODMAP guidelines. This is a perfect example of exploring the Yellow Light items within the app. Sun-dried tomatoes are indeed Yellow Light, and you might therefore passed them by and not realized that you can indeed have a small amount.
Muir Glen has both Crushed and Diced Fire Roasted Tomatoes and we love these products. The tomatoes are roasted until the skins are charred and this lends a slightly, but not overpowering, smoky flavor.
Whole Foods also has 365 Everyday Value Organic Diced Fire Roasted Tomatoes, which contain Organic unpeeled fire roasted tomatoes, Organic tomato juice, Sea salt, Calcium chloride, Citric acid
Most brands that we have investigated contain onion, garlic and/or bell pepper, celery, high fructose corn syrup, herbs and spices among other ingredients. At this point we suggest that you steer clear of this particular item.
A Special Mention For Pomi Brand Tomato Products
These aseptic packaged, shelf stable items have a nice short ingredient list, which makes them great for FODMAPers. Their Chopped Tomatoes, Finely Chopped Tomatoes and Strained Tomatoes all have one ingredient – tomatoes! They also now have organic versions of the Chopped and Strained.
Some General Tips
- If organic is important to you, scan the shelves. Many of the larger companies are now making an organic version of their standard offerings.
- Also, it is common to be able to find sodium free or reduced sodium versions and this might be more desirable for you.
- As always read labels. Many canned tomato products come flavored and would not be low-FODMAP such as tomato pastes with roasted garlic or diced tomatoes that contain onion, garlic and high fructose corn syrup. It is easy to grab the wrong product, as they are side-by-side with the items we are looking for.