A practical label check
What should you check on the packet?
- Check the ingredient list for an inulin-type fibre (inulin, chicory root fibre, chicory fibre).
- Check for a polyol sweetener (maltitol, sorbitol, xylitol, erythritol) and any laxative-effect warning.
- Check for a gum thickener (guar gum, xanthan gum).
- Compare the labelled serving with the amount you actually ate — a whole bar can be more than one serving.
What the label can tell you
The label can show whether an inulin-type fibre, a polyol sweetener and a gum thickener are present, their approximate order by weight, and whether the pack states more than one serving per bar.
What the label cannot tell you
It cannot usually show the grams of chicory root fibre or maltitol, the combined fermentable load of all three ingredient families together, or your personal threshold.
Worked UK label
How to reason through this ingredient list
Fixture: chocolate peanut high-protein bar
Milk protein, chicory root fibre, sweetener (maltitol), peanuts, cocoa butter, guar gum, cocoa mass, natural flavouring. 60g bar, nutrition information per bar.
- What stands out
- All three bloating-relevant ingredient families are present in one product: chicory root fibre (an inulin-type fructan), maltitol (a polyol) and guar gum (a fermentable thickener). The bar is sold and normally eaten as a single 60g serving. Bars such as Quest list a related pairing among their main ingredients — soluble corn fibre and erythritol, a fermentable fibre and a polyol sweetener — showing this is not a pattern unique to one fixture or brand.
- Reasonable conclusion
- The label shows three separate, plausible clues rather than one; treating any single ingredient as “the” cause would miss the other two.
- What we cannot conclude
- None of the three quantities is stated, so the label cannot show whether their combined amount is unusually high or fine for a particular person.
Common questions
Questions people ask about this label
Why do protein bars seem to cause more bloating than other snacks?
They often combine more bloating-relevant ingredient families in one product than a typical snack: an inulin-type fibre used to boost the fibre count, a polyol sweetener used to cut sugar, and a gum used to hold the bar together. Each is an established clue on its own; a bar can present two or three of them at once.
SourcesEFSA inulin opinionPolyol systematic reviewUK approved-additives list
Is the protein itself the problem?
Protein is not a FODMAP and is not the ingredient class linked to bloating in this research. The more checkable clues in a protein bar are the added fibre, the sweetener and the gum used to reach its protein and texture targets, not the protein content shown on the front of the pack.
Does “high fibre” on a protein bar tell me how much chicory root fibre is in it?
Not usually. “High fibre” is a claim about total fibre from every source in the bar, which can include chicory root fibre, oat fibre and others together. The label rarely states chicory root fibre in grams on its own.
Why does “no added sugar” not mean no polyols?
Maltitol and similar polyols are commonly used to replace sugar while keeping a bar sweet and chewy. A “no added sugar” claim describes sugar, not polyols, so a bar can carry that claim and still contain a substantial polyol dose.
Why does eating one bar sometimes mean more than one labelled serving?
Some bars are formulated and labelled as two or more servings even though people normally eat the whole bar in one go. Fermentable fibre, polyol and gum amounts scale with however much of the bar was actually eaten, not with the manufacturer’s serving size.
SourcesMonash FODMAP-stacking guidanceUK food-labelling guidance
When should bloating after eating protein bars be discussed with a clinician?
Speak with a GP if bloating is regular, persists despite trying different products, or occurs with unintentional weight loss or blood in the stool. Seek urgent help for sudden severe pain, vomiting blood, a severely swollen abdomen, or being unable to pass urine, stool or wind.
SourcesNHS bloating guidance
Evidence and uncertainty
Why protein bars make you bloated (even the ‘healthy’ ones): how strong is the evidence?
Human evidence supports dose-related gastrointestinal effects for inulin-type fructans, several polyols and guar gum individually. There is no dedicated human evidence testing the three combined in a commercial protein bar, so the combination is a reasonable inference rather than a directly studied exposure.
SourcesEFSA inulin opinionFibre-tolerance reviewPolyol systematic reviewUK food-labelling guidanceUK approved-additives listMonash label-reading guidanceMonash FODMAP-stacking guidanceNHS bloating guidance
References
Sources used for this page
- EFSA Panel (2015), Chicory inulin and maintenance of normal defecation
- Mysonhimer and Holscher (2022), Gastrointestinal effects and tolerance of nondigestible carbohydrates
- Lenhart and Chey (2017), Systematic review of polyols and gastrointestinal health
- UK Government, Food labelling: giving food information to consumers
- Food Standards Agency, Approved additives and E numbers
- Monash University, Label reading and how to spot FODMAPs
- Monash University, FODMAP stacking explained
- NHS, Bloating
Written and evidence-checked by the GutGuard editorial team. We favour official UK guidance, systematic reviews and primary human research, and label animal, laboratory and exploratory findings clearly. Read our editorial method.