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Foods that cause bloating/Onions

Food + bloating

Do onions cause bloating?

Short answer

Onions are rich in fructansOnions are one of the clearest high-fructan foods. Cooking softens the onion but does not remove the water-soluble fructans from the dish.
FODMAP readHigh

Brown, red and white onion are high in fructans.

01

Two ways it can happen

  1. 01

    Fructans can pass through the small intestine and ferment in the colon, producing gas.

  2. 02

    Onion powder concentrates the same issue and hides in stock, seasoning and sauces.

02

Portion changes the test

A visible onion slice is easy to spot; powder in a sauce can be harder to count.

03

Run a clean meal test

Cook the same meal with green spring-onion tops or chives. Keep garlic out so the onion test stays clean.

Use the free 7-day food diary

04

Check the rest of the meal

Does garlic cause bloating?Garlic packs a concentrated fructan doseDo beans cause bloating?GOS and portion explain the classic reactionDoes bread cause bloating?Wheat fructans and portion are strong suspects

Stop guessing from one meal

Bloatless checks the pattern across your week.

Snap each meal, tap how you feel an hour later, and get a ranked Trigger Report based on your own logs.

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Sources and scope

We use these references for the general digestive mechanisms on this page. Food tolerance still depends on your portion, preparation and health history.

This page provides general information, not a diagnosis. Talk to a clinician about severe or persistent bloating, vomiting, blood in your stool, fever or unexplained weight loss. Ask about celiac testing before removing gluten from your diet.