Wholegrain Bread
Serving sizes
Wholegrain Bread changes rating with portion size. These are the amounts tested in the literature behind our ratings.
- 2 slices (52g)
- 2¾ slices (73g)
Wholegrain Bread sits at Moderate FODMAP, driven by the Fructans and GOS from its wheat and grains.
- The Fructans and GOS in wheat-based wholegrain bread put it at moderate at 2 slices (52g), a comfortable landing spot for many people.
- As the slices add up, both subgroups climb together and the load tips into high, so portion size is really what matters here.
Enjoying it around the 2-slice mark, or reaching for sourdough or oat-based options, can keep things gentle.
Per 2 slices (52g): 0.36g fructans, 0.31g GOS.
Why wholegrain bread is rated moderate
Wholegrain bread carries two FODMAP subgroups at once, fructans and GOS, both coming from the wheat and the grains baked into it. Together they put it at moderate at 2 slices (52g), the smallest serving tested, so the everyday two-slice sandwich is already the portion to respect rather than the easy option. What makes this loaf worth watching is how short the climb is: the ladder turns high at 2¾ slices (73g), which is less than one whole extra slice past the moderate rung. Two subgroups rising together is why it tips so fast.
What changes your risk
- How many slices This is the lever that matters most, and the margin is thin. Moderate sits at 2 slices (52g) and high arrives at 2¾ slices (73g), so less than one extra slice separates the two rungs.
- Stacking on the fructan side Wholegrain bread shares its fructans with wheat pasta, couscous, wheat crackers and wheat breakfast cereal. A wholegrain sandwich at lunch and a pasta dinner add their fructans together even though each is counted separately.
- Stacking on the GOS side The GOS in this loaf lands in the same pile as the GOS in legumes such as chickpeas, lentils and baked beans, and in cashews and pistachios. A wholegrain sandwich next to a bean soup is a bigger GOS load than either one suggests on its own.
- A long sourdough fermentation A slow, traditional sourdough starter breaks down much of the fructan in wheat and spelt before the loaf is baked, which is why traditional sourdough wheat and spelt loaves are treated differently from ordinary yeasted wholegrain bread. A quick loaf labelled sourdough flavoured has not had that fermentation.
- Added fibre in the loaf Some wholegrain and high-fibre breads have inulin or chicory root fibre added to the dough. That is extra fructan on top of what the grain already brings, and it is only visible in the ingredients list.
Swaps
For the hearty, seeded, chewy role that wholegrain bread plays, a wholegrain gluten free loaf or a traditional sourdough spelt loaf are the swaps that genuinely fill it, and pumpkin seeds or walnuts on top bring back the texture people miss. Oats make the same sort of breakfast, and potato, rice, quinoa and polenta cover the starch when bread is not essential. What does not work as a swap is any other ordinary wheat, rye or barley bread, including multigrain, seeded wheat and light rye, because those carry the same fructans, and a loaf with inulin or chicory root fibre in it is going the wrong way. Legume-flour breads are not the answer either, since they lead with the same GOS this loaf already has.
How to lower the load
Weight matters more than slice count here, because wholegrain loaves are cut very differently: a dense bakery tin loaf and a soft supermarket sandwich loaf both give you two slices, but only one of them is near 2 slices (52g). Check the pack for the slice weight if it lists one, and treat a thickly cut artisan loaf as more bread than the ladder describes. Read the ingredients before buying, since inulin and chicory root fibre turn up in exactly this kind of loaf. Freezing the bread and pulling out only the slices you intend to eat keeps the portion deliberate, and an open sandwich or a sandwich built with one slice of wholegrain and one of gluten free bread keeps the wholegrain side of the meal below the tested serving.
Common questions
how many slices of wholegrain bread can i have on low fodmap
The published serving data has wholegrain bread at moderate at 2 slices (52g) and high at 2¾ slices (73g). No smaller serving has been tested, so the moderate rung is the lowest rung there is.
why is wholegrain bread moderate and not low
It carries two subgroups at once, fructans and GOS, both from the wheat and grains in the loaf. Their combined load is already moderate at the smallest tested serving of 2 slices (52g).
is wholegrain bread high in gos
GOS is one of the two subgroups in wholegrain bread, alongside fructans. It is part of what makes 2¾ slices (73g) high, and it is the reason a wholegrain sandwich eaten with chickpeas, lentils or baked beans adds up faster than it looks.
is wholegrain bread better than white bread on a low fodmap diet
Both sit at moderate at their smallest tested servings, so neither is the relaxed choice. Wholegrain brings GOS as well as fructans, which matters when the rest of the meal includes legumes or cashews.
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Informational only, not medical advice. Individual tolerance varies. Talk to a healthcare professional or a dietitian for personal guidance.
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 September 22, 2026.