How to Read Food Labels on a Low-FODMAP Diet

Settled Health

Ingredient lists are where the low-FODMAP diet gets tricky. A product can look healthy, contain no obvious trigger foods, and still be loaded with hidden FODMAPs. Here's what to look for, what to ignore, and why the "2% or less" section matters more than you think.

The Ingredients That Matter Most

Fructans (the most common hidden FODMAP):

Garlic and onion are the biggest offenders, and they show up everywhere. Sauces, dressings, seasoning blends, soups, marinades, chips, and stock cubes. Look for: garlic, garlic powder, garlic salt, garlic extract, onion, onion powder, onion salt, dehydrated onion, shallot, leek, and scallion.

Garlic powder is concentrated roughly 5:1 from fresh garlic. One teaspoon of garlic powder equals two to three fresh cloves. Monash University flags garlic powder as high-FODMAP at just one quarter of a teaspoon.

Also watch for prebiotic fibers: inulin, chicory root, chicory root fiber, FOS (fructo-oligosaccharides), and oligofructose. These are added to "high fiber" and "gut health" products specifically because they're fermentable, which is exactly the problem for IBS.

Fructose:

High fructose corn syrup, crystalline fructose, honey, agave syrup, and fruit juice concentrate (especially apple and pear). Regular table sugar is fine because it contains equal glucose and fructose. Fructose is only a FODMAP when it exceeds glucose in the same food.

Lactose:

Milk, cream, buttermilk, whey, whey protein concentrate, milk powder, and milk solids. Aged hard cheeses like cheddar, parmesan, and swiss are safe because aging eliminates nearly all lactose.

GOS:

Chickpeas (also called garbanzo beans), lentils, cashews, pistachios, lupin flour, and soy flour. Lupin is common in European gluten-free products and easy to miss.

Polyols (sugar alcohols):

Sorbitol, maltitol, xylitol, isomalt, and mannitol. In European products, look for E-numbers: E420 (sorbitol), E421 (mannitol), E953 (isomalt), E965 (maltitol), E967 (xylitol).

Why "2% or Less" Still Matters

Many ingredient lists have a "Contains 2% or less of:" section. For most dietary concerns, these trace amounts don't matter. For FODMAPs, they absolutely do.

In a 30g serving, 2% means up to 0.6g of that ingredient. The published FODMAP threshold for fructans is just 0.2 to 0.3g per serving (Varney et al. 2017). That means even at "2% or less," garlic, onion, inulin, and chicory root can exceed your threshold. Polyol thresholds are similarly low at 0.2g.

This is why garlic and onion should always be flagged regardless of where they appear on the label.

The Tricky Ones

"Natural flavoring" or "natural flavors" can contain garlic or onion extracts. There's no way to know from the label. If you're in the elimination phase and a product contains natural flavoring, treat it as suspect.

"Dehydrated vegetables" or "vegetable powder" almost always include garlic or onion.

"Spices" is technically regulated and shouldn't contain garlic or onion under US law, but the ambiguity makes many people cautious.

Safe Ingredients People Mistakenly Avoid

Erythritol is not a FODMAP despite being a sugar alcohol. It's absorbed in the small intestine and does not reach the colon for fermentation. Don't confuse it with sorbitol, maltitol, or xylitol, which are FODMAPs.

Maltodextrin sounds like maltitol but is a completely different compound. It's a glucose polymer and is FODMAP-safe.

Dextrose sounds like fructose but is just another name for glucose. Totally safe.

Corn syrup (not high fructose corn syrup) is glucose-based and safe.

Soy lecithin is safe. The GOS concern with soy comes from soy flour and whole soybeans, not the lecithin extract.

Stevia and monk fruit are safe sweetener alternatives.

What Labels Can't Tell You

Monash University has stated directly that "it is not possible to accurately determine the FODMAP content based on a list of ingredients." Processing changes everything. Sourdough fermentation for 12 hours reduces fructans by up to 69%. Canning and draining chickpeas reduces GOS because it leaches into the liquid. Garlic-infused oil is safe because fructans are not oil-soluble, but only if no garlic pieces remain.

Labels show ingredients, not quantities per subgroup. That's why scanning is useful as a first-pass filter, but precise tracking requires knowing the actual FODMAP composition of the food. For more on why hidden ingredients cause symptoms, read about FODMAP stacking and what to do during an IBS flare.

Settled's barcode scanner flags hidden onion, garlic, and inulin in packaged foods — including the '2% or less' section other apps miss. Free to start. Try Premium free for 7 days.