Leek (green part)

Why leek (green part) is rated low

Leek greens come in low at 1 cup chopped (75g), and no FODMAP subgroup is recorded for the green leaves, which is what makes them one of the most useful foods on the diet: they bring a soft onion flavour to a pot without the part of the plant that causes the trouble. For this purpose the leek is really two foods. The dark green tops are the low part, while the white and pale green base is a high FODMAP food of its own. The rating is estimated from what the leaves are made of, and 1 cup chopped (75g) is the tested serving, so that is the amount to build a soup or braise around.

What changes your risk

• Where you cut This is the lever that matters most. Keep the dark green leaves and stop where they turn pale and tightly wrapped. The pale green and white section is the bulb, and a few rings of it in the pot undo the whole swap.
• Serving size 1 cup chopped (75g) is the tested serving and the only one published for the greens, so it is the figure to measure against. Larger amounts are not tested here.
• The stock and seasoning around it Leek greens usually go into soups and braises, and those are often built on stock cubes, bouillon, gravy granules or spice blends that carry onion and garlic powder. The greens stay low; the dish does not if the stock is the problem.
• Stacking across the meal A low rating is per serving, not per meal. A soup that piles several vegetables into the pot at their full tested servings adds up to a bigger total load, so keep the other vegetables at modest amounts too.
• Dried leek and soup mixes Dried leek flakes and packet soup mixes rarely say which part of the plant they use, and drying concentrates whatever is there, so fresh green leaves are the reliable choice.

What else works

For the same mild onion note, the green tops of spring onions and chives do the job raw or scattered at the end, and garlic-infused oil is the base to start the pan with, as long as no pieces are left sitting in the oil. A pinch of asafoetida in hot oil adds a savoury allium depth to soups and curries. What is not a swap, however it is labelled: the leek bulb or its pale green section, onion of any colour including shallot, the white part of spring onion, garlic, and onion powder, garlic powder, onion salt and most stock cubes.

How to keep it low

Buy leeks with plenty of dark green top left on, since some shops trim most of it away. Cut the greens off where they turn pale, split them lengthwise and wash them in a bowl of water: grit hides between the layers and settles to the bottom when you lift the leaves clear. Slice them thinly for soups, braises and stocks and measure 1 cup chopped (75g) per serving. The greens are tougher than the bulb, so give them a little longer in the pan, and freeze extra sliced greens flat in a bag for the next pot of soup.

Common questions

are leek greens low fodmap

Yes. The dark green leaves are low at 1 cup chopped (75g). The white and pale green base is high FODMAP, so cut where the leaves turn pale.

how much leek greens can i eat on low fodmap

1 cup chopped (75g) per serving is the tested amount and the one to measure against. Larger amounts are not tested here.

can you use leek greens instead of onion

Yes, that is their main job on a low FODMAP diet. Soften the greens in garlic-infused oil as the base for soups, stews and sauces, and add chives or spring onion greens at the end for a fresher note.

is leek soup low fodmap

Only when it is made with the green leaves, not the bulb, and a stock without onion or garlic. Most leek soups use the white part and a standard stock, which puts them well above low.