We've written before about what to look for in a protein powder. This is the other half — the specific sources and ingredients that consistently cause trouble, so you know exactly what to check the label for.
What to avoid
Whey protein concentrate. Carries meaningful lactose. Even "isolate" versions aren't always fully clear — check for "less than 1% lactose" specifically.
Inulin and chicory root fibre. Added because it sounds healthy, but it's one of the most common bloating triggers in protein products, dairy or plant-based.
Sugar alcohols. Sorbitol, xylitol, maltitol, erythritol — used to sweeten "low sugar" products, and notorious for gas and bloating even in small amounts.
Silken tofu and whole soybeans. Soy protein isolate itself is generally fine, but whole soy foods carry more FODMAPs than people expect.
What to look for instead
Rice and pea protein, properly processed, are inherently gentle. Look for genuinely tested low FODMAP formulations rather than products that simply avoid mentioning the topic.
Frequently asked questions
What protein sources should I avoid if I have IBS?
Whey protein concentrate (lactose), protein powders with inulin or chicory root, and anything sweetened with sugar alcohols like sorbitol or xylitol are the most common triggers.
Is soy protein bad for IBS?
Soy protein isolate is generally low FODMAP, but whole soybeans and silken tofu are higher FODMAP — the processing matters more than the source.
Free UK delivery on orders over £30. Every That Protein blend is built low FODMAP from the ingredient list up.