Flour and FODMAPs: 20 foods rated

Chickpea flour is a milled pulse, where the GOS survives the milling. A flour concentrates whatever the seed held into a form used by the cupful, which is why the same plant can be low as a portion and high as a baked good. This food is not among the 55 grain products behind this axis's per-portion figures, so its level is a placing and not a measurement.

• Biesiekierski J et al., J Hum Nutr Diet 24 (2011) 154-176, fructans and galacto-oligosaccharides per portion as eaten
• Whelan K et al., Int J Food Sci Nutr 62:5 (2011) 498-503, fructan measured in wheat, rye and gluten-free breads

Lupin flour is a legume flour and carries legume GOS, and it turns up in gluten-free bakery as a protein and colour booster - so a bread bought precisely to avoid wheat can be high here. It is also a declared allergen in the EU, which is a separate matter on a separate axis.

Rye flour concentrates a grain that was already the highest of the cereals in FODMAPs, and it is used in dense breads eaten in thin slices - which is the only thing working in its favour. A single slice of pumpernickel is a smaller dose than a sandwich made of wheat bread.

Soy flour keeps the whole bean's GOS with nothing washed out, and it is used as a protein booster in bread, protein bars and meat substitutes - foods that do not announce themselves as soy. Fermented soy is the exception: tempeh's mould consumes these same sugars.

Wheat flour concentrates the grain's fructans into something eaten by the hundred grams - a loaf, not a spoonful. That quantity is what puts flour here rather than the concentration, and it is why bread is the single biggest fructan source in most Western diets. Long sourdough fermentation lowers it; a two-hour rise does not. Across the bread aisle the brand decides more than the type, gluten-free loaves included.

• Whelan K et al., Int J Food Sci Nutr 62:5 (2011) 498-503, fructan measured in wheat, rye and gluten-free breads

Coconut flour carries both sorbitol and fructans, and it is used in large proportions in gluten-free baking - a cup of it where wheat flour would have gone. The quantity is what puts it here, not the concentration.

• Tuck C et al., J Hum Nutr Diet 31 (2018), FODMAP content of common plant-based and processed foods
• USDA FoodData Central, the national nutrient database, queried for the sugar profile
• Lenhart A. & Chey W.D., Adv Nutr 8 (2017) 587-596, systematic review of the effects of polyols

Wholemeal flour keeps the bran and the germ, and it measures slightly higher in FODMAPs than white for the same weight. The gap is small - smaller than most people expect from how differently the two are marketed - and it is portion size, not the choice between them, that decides the outcome. Across the bread aisle the brand decides more than the type, gluten-free loaves included.

• Whelan K et al., Int J Food Sci Nutr 62:5 (2011) 498-503, fructan measured in wheat, rye and gluten-free breads

Almond flour is ground almonds, low at a quarter cup. A flour concentrates whatever the seed held into a form used by the cupful, which is why the same plant can be low as a portion and high as a baked good. This food is not among the 55 grain products behind the per-portion FODMAP figures, so its level is a placing and not a measurement.

• Biesiekierski J et al., J Hum Nutr Diet 24 (2011) 154-176, fructans and galacto-oligosaccharides per portion as eaten
• Whelan K et al., Int J Food Sci Nutr 62:5 (2011) 498-503, fructan measured in wheat, rye and gluten-free breads

Flax flour is a seed, used a tablespoon at a time. A flour concentrates whatever the seed held into a form used by the cupful, which is why the same plant can be low as a portion and high as a baked good. This food is not among the 55 grain products behind the per-portion FODMAP figures, so its level is a placing and not a measurement.

• Biesiekierski J et al., J Hum Nutr Diet 24 (2011) 154-176, fructans and galacto-oligosaccharides per portion as eaten
• Whelan K et al., Int J Food Sci Nutr 62:5 (2011) 498-503, fructan measured in wheat, rye and gluten-free breads

Oat flour is milled oats and nothing is removed by milling, so it carries what the grain carries — 0.11 g of fructan per portion as eaten in the measured oat.

• Biesiekierski J.R. et al., J Hum Nutr Diet 24 (2011) 154–176, fructans and short-chain carbohydrates in 55 grains, breads and pulses, reported in grams per portion as eaten

Rice flour is the milled form of the one grain that measured 0 g of fructan per portion as eaten in a survey of 55 grain products. What was measured is the grain and not the flour, and milling removes the bran rather than anything this axis counts.

• Tuck C et al., J Hum Nutr Diet 31 (2018), FODMAP content of common plant-based and processed foods
• Biesiekierski J et al., J Hum Nutr Diet 24 (2011) 154-176, fructans and galacto-oligosaccharides per portion as eaten
• USDA FoodData Central, the national nutrient database, queried for the sugar profile

Spelt flour is a wheat, and sourdough spelt is lower than yeasted spelt. A flour concentrates whatever the seed held into a form used by the cupful, which is why the same plant can be low as a portion and high as a baked good. Long fermentation is the one process that lowers it: the yeast eats the fructan given hours rather than minutes. This food is not among the 55 grain products behind this axis's per-portion figures, so its level is a placing and not a measurement. Across the bread aisle the brand decides more than the type, gluten-free loaves included.

• Biesiekierski J et al., J Hum Nutr Diet 24 (2011) 154-176, fructans and galacto-oligosaccharides per portion as eaten
• Whelan K et al., Int J Food Sci Nutr 62:5 (2011) 498-503, fructan measured in wheat, rye and gluten-free breads