King Trumpet Mushroom
Serving sizes
King Trumpet Mushroom changes rating with portion size. Its rating is estimated from what it is made of, so the servings are described rather than weighed.
- Small serving
- Large serving
King trumpet mushrooms are High FODMAP, carrying the same fermentable sugar alcohol found across most mushrooms.
- The driver here is Mannitol, which mushrooms are naturally rich in; even a small serving sits at moderate and it climbs to high at a large serving.
- These meaty mushrooms show up in stir-fries, roasts, and as a scallop stand-in, and cooking them down doesn't remove the mannitol, so the amount on your plate is what really counts.
For a savory, umami hit without the mannitol, oyster mushrooms are a well-loved low-FODMAP swap in the same dishes.
Why king trumpet mushroom is rated high
King trumpet mushroom is rated high FODMAP overall, and mannitol is what drives it. The rating is estimated from what the mushroom is made of rather than a measured serving. Even at its smallest it is not a low FODMAP food: a Small serving reads MODERATE, and a Large serving reads HIGH. There is no rung where it comes in low, so cutting back lowers the load without making it safe for the elimination phase.
What changes your risk
- Serving size A Small serving reads MODERATE and a Large serving reads HIGH. The ladder has no low rung, so a smaller helping is less, not low.
- Cooking method Searing, roasting, grilling and frying do not lower mannitol, because heat does not break it down and the mannitol stays in the mushroom. Cooking drives off water and shrinks the pile on the plate, but all the mannitol from the raw amount is still there.
- Stacking with other mannitol foods Serving king trumpet with other mushrooms, cauliflower or celery in the same meal adds mannitol on mannitol and pushes the total further up.
- Mannitol-sweetened products Sugar-free sweets sweetened with mannitol add to the same total, so one after a mushroom dish stacks the load.
- Mixed mushroom packs King trumpet often comes in mixed or wild mushroom blends, and the other mushrooms in the pack are not a low FODMAP way to stretch the dish.
Swaps
King trumpet is prized for its meaty, chewy texture and its role as a plant-based scallop stand-in, and the honest swaps fill that role without mushrooms. Pressed firm tofu, cut into rounds and seared hard, takes the scallop shape and a golden crust well. Real scallops or other plain fish do the job if you eat seafood. In a stir-fry, zucchini batons, bok choy, green beans and bell pepper give bulk and bite, and grated parmesan brings back savoury depth in pasta or rice dishes. Other mushrooms, including oyster, button and portobello, are not a low FODMAP swap.
How to lower the load
Judge the portion raw, not cooked: king trumpet shrinks a lot in the pan, so a modest-looking cooked portion can come from a Large serving of raw mushroom. When buying, choose firm, dry stems with no soft or slimy spots, store them in a paper bag in the fridge, and slice just before cooking. If it appears on your plate, build the rest of the meal from low FODMAP foods with no mannitol, such as rice, potato, carrots and bok choy, rather than other mushrooms or cauliflower. When eating out, vegetarian scallops, mushroom stir-fries and mushroom risottos often use king trumpet, so ask what is in them. Tolerance is individual, and reintroducing mannitol is something to work through with a dietitian.
Common questions
is king trumpet mushroom low fodmap
No. It is rated high FODMAP overall because of mannitol, estimated from what it is made of. A Small serving reads MODERATE and a Large serving reads HIGH.
is king trumpet mushroom high in mannitol
Yes. Mannitol is the subgroup that drives its rating, which climbs from MODERATE at a Small serving to HIGH at a Large serving.
does cooking king trumpet mushrooms lower fodmaps
No. Searing, roasting and grilling do not break mannitol down, and because the mushroom shrinks as it cooks, a cooked portion can hold more mannitol than it looks.
what can i use instead of king trumpet mushroom scallops
Pressed, seared rounds of firm tofu give a similar shape and golden crust, and real scallops or other plain fish work if you eat seafood. Other mushrooms are not a low FODMAP swap.
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Learn more
Informational only, not medical advice. Individual tolerance varies. Talk to a healthcare professional or a dietitian for personal guidance.
King Trumpet Mushroom is an estimated rating: it is inferred from the food's ingredients and composition and cross-checked, not measured directly in the papers below. The low, moderate and high cutoffs are still those of Varney et al. (2017).
References
- Fructan and free fructose content of common Australian vegetables and fruit. Muir et al. (2007), J. Agricultural and Food Chemistry 55(16):6619-6627.
- Measurement of short-chain carbohydrates in common Australian vegetables and fruits by HPLC. Muir et al. (2009), J. Agricultural and Food Chemistry 57(2):554-565.
- Quantification of fructans, galacto-oligosaccharides and other short-chain carbohydrates in processed grains and cereals. Biesiekierski et al. (2011), J. Human Nutrition and Dietetics 24(2):154-176.
- Dietary sorbitol and mannitol: food content and distinct absorption patterns. Yao et al. (2014), J. Human Nutrition and Dietetics 27(Suppl 2):263-275.
- FODMAPs: food composition, defining cutoff values and international application. Varney et al. (2017), J. Gastroenterology and Hepatology 32(Suppl 1):53-61. Supplies the low, moderate and high cutoffs used on this page.
Last reviewed October 17, 2026.