Kewpie mayonnaise is likely low FODMAP based on its listed ingredients, but it comes with one caveat that matters: the label includes “natural flavors,” which could potentially hide small amounts of garlic, onion, or other high-FODMAP ingredients. None of the other ingredients in Kewpie mayo are known FODMAP triggers, and the product has not been formally tested or certified by Monash University or FODMAP Friendly.
Breaking Down the Ingredients
The U.S. version of Kewpie mayonnaise contains soybean oil, egg yolks, water, distilled vinegar, salt, sugar, mustard flour, red wine vinegar, rice vinegar, yeast extract, and natural flavors. The product also contains MSG. Running through that list from a FODMAP perspective, most of it checks out cleanly.
Soybean oil is a fat with no fermentable carbohydrates, so it’s not a FODMAP concern. Egg yolks are protein and fat, also fine. Distilled vinegar, red wine vinegar, and rice vinegar are all low FODMAP. Salt, sugar in the small amounts present in mayo, and mustard flour are similarly safe at normal serving sizes.
That leaves three ingredients worth a closer look: MSG, yeast extract, and natural flavors.
MSG and Yeast Extract
MSG (monosodium glutamate) is not a FODMAP. FODMAPs are specific types of fermentable carbohydrates, and MSG is a sodium salt of an amino acid. It contains no fructose, lactose, fructans, galactans, or polyols. Some people with IBS report sensitivity to MSG through other mechanisms, but from a strict FODMAP standpoint, it’s not a concern.
Yeast extract functions as a flavor enhancer and is similarly not classified as a high-FODMAP ingredient. It’s a source of free glutamate (the same compound in MSG) and appears on the ingredient list in a small enough quantity that it falls well below any FODMAP threshold. Monash University has not flagged yeast extract as problematic for the low FODMAP diet.
The “Natural Flavors” Question
This is where certainty ends. “Natural flavors” is a broad category that can include extracts from garlic, onion, or other high-FODMAP foods. In the United States, manufacturers are not required to specify what’s in their natural flavors blend unless it contains a major allergen. Garlic and onion are not allergens, so they can sit inside that term without disclosure.
For Kewpie’s Deep Roasted Sesame Dressing, at least one person contacted the company directly and confirmed it contains no garlic or onion in its natural flavors. No similar confirmation has been publicly shared for the original mayonnaise. If you want to be thorough during the elimination phase, contacting Kewpie directly to ask about garlic and onion in their mayo’s natural flavors is the most reliable approach.
That said, mayonnaise as a category rarely contains garlic or onion. The natural flavors in Kewpie mayo more likely refer to flavoring agents that contribute to its distinctive umami-rich, slightly sweet taste profile. The risk is low, but it’s not zero.
How Kewpie Compares to Other Mayonnaise
Standard mayonnaise made from oil, eggs, vinegar, and salt is considered low FODMAP by Monash University at typical serving sizes (around two tablespoons). Most store-bought mayo brands follow this basic formula and are safe on a low FODMAP diet. The main things to watch for across any mayo brand are added garlic, onion, honey, high-fructose corn syrup, or apple cider vinegar in flavored varieties.
Kewpie’s ingredient list is actually simpler than many American mayonnaise brands, which sometimes add soybean oil blends, calcium disodium EDTA, or other preservatives. The biggest difference between Kewpie and standard mayo is the use of egg yolks only (no egg whites), plus MSG and yeast extract for that characteristic savory depth. None of those differences create FODMAP issues.
Practical Tips for Using Kewpie on a Low FODMAP Diet
If you’re in the elimination phase, where precision matters most, stick to two tablespoons or less per serving. This is the portion size Monash has tested for regular mayonnaise. Kewpie’s richer flavor compared to standard mayo means you may naturally use less of it anyway.
Keep in mind that the Japanese-made version of Kewpie (sold in the squeeze bottle with the baby logo) may have a slightly different ingredient list than the U.S.-made version. Always check the label on the specific product you’re buying. The Japanese version traditionally uses a spirit vinegar or apple vinegar blend and may include different flavor components. Apple vinegar in small amounts is generally fine, but it’s worth scanning the label each time.
If the “natural flavors” uncertainty bothers you during elimination, consider using a mayo brand that has been formally certified low FODMAP, or make your own with oil, egg yolks, lemon juice, salt, and mustard. Once you’ve completed the elimination phase and moved into reintroduction, testing Kewpie mayo is a low-risk experiment since the overwhelming majority of its ingredients are clearly safe.