Vegetables and oligosaccharides: 61 foods rated

Same reason as the FODMAP level: the artichoke stores its reserve as inulin, a long fructan chain, and inulin is the textbook oligosaccharide. It is the plant this whole family of compounds was first isolated from. Muir measured the fructans in 60 vegetables and put these five at the top — garlic, artichoke, shallot, leek bulb and onion — across a range of 1.2 to 17.4 g per 100 g fresh weight for the group. The paper does not rank them against one another.

• Muir J.G. et al., J Agric Food Chem 55 (2007) 6619–27 and 57 (2009) 554–65, fructans and short-chain carbohydrates measured in Australian vegetables and fruit

Same reason as the FODMAP level: black bean GOS, and a cooking tradition that keeps the liquid on purpose. Where the water stays, the oligosaccharides stay. Pulse oligosaccharides are water-soluble, and that is the practical point: the level here follows work on pulses AND on what cooking does to them, because soaking and boiling move part of them into water that is usually thrown away.

• Reddy N. et al., Food Chemistry 13 (1984) 25-68, and Wang N. et al., Food Res Int 43 (2010) 589-594, oligosaccharides of pulses and the effect of cooking

Same reason as the FODMAP level: asparagus stores fructooligosaccharides in the spear, and the spear spends them after cutting. Fructans are water-soluble, so the cooking water takes a share - one of the few kitchen levers that works here. The spear's fructooligosaccharides are the measured part.

• Shiomi N et al., J Appl Glycosci 54 (2007), fructooligosaccharides of asparagus
• Muir J et al., J Agric Food Chem 55 (2007) and 57 (2009)

Leek: same reason as the FODMAP level, with the same split: the fructans sit in the white bulb and the dark green leaf carries far less. It is the one allium you can use half of. Muir measured the fructans in 60 vegetables and put these five at the top — garlic, artichoke, shallot, leek bulb and onion — across a range of 1.2 to 17.4 g per 100 g fresh weight for the group. The paper does not rank them against one another.

• Muir J.G. et al., J Agric Food Chem 55 (2007) 6619–27 and 57 (2009) 554–65, fructans and short-chain carbohydrates measured in Australian vegetables and fruit

Onion carries mostly GF2 - three units, about as short as a chain gets while still counting. Short chains ferment quickly, which is why onion produces symptoms faster than the long-chain inulin in a fibre supplement does. Muir measured the fructans in 60 vegetables and put these five at the top — garlic, artichoke, shallot, leek bulb and onion — across a range of 1.2 to 17.4 g per 100 g fresh weight for the group. The paper does not rank them against one another. One figure puts this in proportion, and it is about the diet rather than the plant: in a survey of more than 15,000 Americans, WHEAT SUPPLIED ABOUT 70 PER CENT of all the inulin and oligofructose eaten, and onions about 25 - two foods for roughly 95 per cent of the total, against a daily average of 2.6 g of inulin and 2.5 g of oligofructose. That share belongs to a particular cuisine, not to the crop: a diet built on chicory or artichoke would divide differently.

• Muir J.G. et al., J Agric Food Chem 55 (2007) 6619–27 and 57 (2009) 554–65, fructans and short-chain carbohydrates measured in Australian vegetables and fruit
• Moshfegh A.J. et al., J Nutr 129:7 Suppl (1999) 1407S-1411S, inulin and oligofructose in the diets of Americans

Same reason as the FODMAP level: pinto bean GOS. Refried beans are reduced rather than drained, so the chains that would have gone into the cooking water are concentrated back into the dish instead. Pulse oligosaccharides are water-soluble, and that is the practical point: the level here follows work on pulses AND on what cooking does to them, because soaking and boiling move part of them into water that is usually thrown away.

• Reddy N. et al., Food Chemistry 13 (1984) 25-68, and Wang N. et al., Food Res Int 43 (2010) 589-594, oligosaccharides of pulses and the effect of cooking

Same reason as the FODMAP level: shallot fructans, among the most concentrated of the alliums by weight. The quantity that flavours a sauce is enough, which is why this is the one that catches people eating out. Muir measured the fructans in 60 vegetables and put these five at the top — garlic, artichoke, shallot, leek bulb and onion — across a range of 1.2 to 17.4 g per 100 g fresh weight for the group. The paper does not rank them against one another.

• Muir J.G. et al., J Agric Food Chem 55 (2007) 6619–27 and 57 (2009) 554–65, fructans and short-chain carbohydrates measured in Australian vegetables and fruit

Same reason as the FODMAP level: artichoke inulin. The heart is the part sold in jars, and jarring helps - inulin is water-soluble and part of it leaves for the brine. The fresh whole artichoke sits higher.

Bitter gourd's oligosaccharides are galacto-oligosaccharides: 1.12 g per 100 g in Prichard's measurement, with no fructans detected. That split matters on this axis, because the two classes are absorbed by different routes and a diet that limits one does not necessarily limit the other.

• Prichard R et al., Int J Food Sci Nutr 67 (2016) 383-390, FODMAP content of foods commonly consumed by ethnic minority groups
• contents per 100 g, not per serve

Broccoli's FODMAP level comes from fructans and from nothing else, so the two axes must agree. The fructan sits mainly in the stalk: trimmed to the florets, the same weight measures lower.

Same reason as the FODMAP level: the GOS accumulate as the soya bean matures, and edamame is picked before that is finished. Less time on the plant means fewer chains.

• Švejstil R. et al., Sci Agric Bohem 46:2 (2015) 73-77, raffinose-series oligosaccharides in soybean products

Kimchi is fermented cabbage, and lactic fermentation consumes sugars - but kimchi is seasoned with garlic, and generously. The fermentation lowers the cabbage's oligosaccharides and does not remove the garlic's.

Spring onion is the allium that can be cut in two: the green tops carry little fructan and the white bulb carries it all. Slicing off the white part is the single most useful substitution on this axis, because it keeps the flavour.

Brussels sprouts carry a small amount of fructan, and their reputation for causing wind comes mostly from the sulphur compounds instead - a different molecule with a different mechanism. A few sprouts is low here; a plateful of them is where the chains start to count.

Cabbage is leaves wrapped around each other, not a storage organ, and it measures low for oligosaccharide chains. Blanching lowers it further, since what little is there dissolves into the water.

Cauliflower is high on the FODMAP axis for a polyol - mannitol - and polyols are the P of the acronym, not the O. Its fructan fraction is small, so the two axes part company here, and a mannitol problem is not solved by anything that helps with chains.

Chicory leaf is low in fructans, and the confusion on this axis comes from its root. The plant's ROOT is the industrial source of inulin — industrial inulin is sold as 'chicory inulin' — and chicory is a Compositae, the family a survey of fructooligosaccharides puts highest of all. But a family rank is not a food rank, and the leaf has been measured since: its fructans run around 0.1% of fresh weight, against 15 to 20% in the root, and the Monash app puts both endive and witloof in the green. The LEAF is the blanched head eaten as a salad; the root, ground for coffee or farmed for inulin, is a different food on this axis and stays high.

• Campbell J.M. et al., J Agric Food Chem 45 (1997) 3076-3082, fructooligosaccharide composition of foods and feeds
• Perovic J et al., Food Chemistry 339 (2021), chicory as a food ingredient, for the leaf-versus-root figures

Dulse is a red alga, and red algae store floridean starch rather than fructans - a glucose-based polysaccharide closer to glycogen than to anything on this axis. It is also eaten in flakes, a gram at a time.

Fennel is a swollen leaf base rather than a true bulb, which is why it does not carry the onion's oligosaccharides despite looking the part. The fronds and seeds are lower still, and the seeds are used in pinches.

Jicama does store inulin, unlike the other roots here - but the measured amount at a normal serving stays low, and it is eaten raw in slices rather than by the bowl. It is the one low root on this axis that is low by quantity rather than by chemistry. Fruit oligosaccharides are the part of this axis least visible on a label: they are not sweetness and not fibre in the usual sense, and two fruits that taste alike can differ several-fold. The level follows measurements made on fruit specifically.

• Muir J. et al., J Agric Food Chem 55 (2007) and 57 (2009), and Jovanovic-Malinovska R. et al., Int J Food Prop 17 (2014), oligosaccharides in fruit

Parsnip is a root that stores starch rather than fructan, which is what separates it from the chicory root it resembles. Two roots that look alike can store their winter reserve in completely different molecules.

Red cabbage answers like white cabbage - the pigment is an anthocyanin and has nothing to do with carbohydrate. Raw in a slaw or braised, it stays low in oligosaccharides either way.

Rocket is a leaf, and leaves store nothing - a plant's fructan reserve goes into roots, bulbs and tubers, the organs that have to survive a winter. Salad leaves are the safest category on this axis for that reason.

Sauerkraut is cabbage that lactic bacteria have already worked on, and they consume the cabbage's oligosaccharides as they go - the fermentation does to the cabbage what the colon would otherwise do. What it produces instead is mannitol, which belongs to the polyol axis.

Seaweed is not a land plant, and fructans and GOS are what land plants store. Algae store different carbohydrates - laminarin, carrageenan, alginate - which human enzymes also cannot split but which are longer chains and ferment more slowly.

Sweet potato stores starch, not fructans - a polysaccharide hundreds of units long rather than a chain of three to ten. Its FODMAP level comes from mannitol at larger servings, which is a polyol and a different letter of the acronym.

Taro is a corm - a swollen stem base - and it stores starch. Starchy tropical staples are consistently low in oligosaccharides, which is why taro, cassava and green plantain do the work potato does elsewhere.