Leek is low FODMAP only up to a point. Safe serving: Green leaves 54 g; white bulb high FODMAP. Beyond that it becomes a problem. The FODMAP group responsible is fructans. Same split as spring onion. The dark green leaves are low FODMAP at 54 g and give you a genuine allium note; the pale bulb is high in fructans and is the part most recipes tell you to use.

Vegetables

Is Leek Low FODMAP?

Portion-dependent

Low FODMAP only up to the serving size listed — larger servings stack.

Safe serving

Green leaves 54 g; white bulb high FODMAP

FODMAP group responsible

Fructans — Oligosaccharides. Wheat, onion, garlic. The most common trigger and the hardest to avoid.

Why

Same split as spring onion. The dark green leaves are low FODMAP at 54 g and give you a genuine allium note; the pale bulb is high in fructans and is the part most recipes tell you to use.

This entry is compiled from published Monash-aligned guidance rather than our own laboratory testing, and thresholds are revised as new data arrives. For the elimination phase the Monash app is the authority. See the full food list for how the categories fit together, orcheck another food.

Is Leek Low FODMAP?

Why

Low-FODMAP Elimination Phase Starter Kit