Lentils

Lentils: pulses are high in FODMAPs because of their galacto-oligosaccharides (GOS), which humans have no enzyme to digest. Canned and well-rinsed pulses measure lower than dried ones boiled at home, because the GOS leach into the water - and a small serving is usually tolerated.

Lentils carry the same GOS as the other pulses but less of them, and they cook without soaking - which is why the level is set by how the pot was handled. Boiled in plenty of water and drained, they land far below the same lentils simmered into a dal that keeps its liquid. 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.

Lentils are near the top of every low-nickel diet sheet, and for a reason that is built into the plant: nickel is the cofactor of urease, the enzyme legumes need to handle nitrogen, so they take it up from the soil deliberately. Soaking and discarding the water removes a little; it does not change the level.

Lentils are high, and they are the pulse that does not get soaked - they cook in twenty minutes straight from dry, which skips the step that would have removed part of the oxalate. Cooking them in plenty of water and draining is the substitute; a dal keeps its liquid and keeps the oxalate. Quinteros measured that on the pulses themselves and found every cooking method lowers the soluble fraction, with microwave and industrial processing more effective than ordinary domestic cooking.

Lentils carry biogenic amines like other pulses, and the amount depends on what happened to the seed: measured content rises during germination and falls with cooking in water that is then discarded. Dried and boiled is the lower form; sprouted lentils and lentils left in their cooking liquid are the higher ones. That pattern was measured in broad bean, chick pea and lupine rather than in the lentil itself: cooking left those seeds free of biogenic amines, which turned up in the boiling water instead.

Lentils are low in salicylate, like most pulses. They matter more on the FODMAP axis than this one.

Lentils are a legume and contain no gluten. They are flagged because dried pulses are grown in rotation with wheat and cleaned on shared equipment, so a stray grain in the bag is the real risk - which is why rinsing and picking over lentils is worth doing for more than one reason.