Green Lentil (boiled)
Serving sizes
Green Lentil (boiled) changes rating with portion size. These are the amounts tested in the literature behind our ratings.
- ½ cup (92.5g)
- ⅝ cup (109g)
Boiled green lentils are Moderate FODMAP at a small serving, driven by their GOS content that climbs to high as the portion grows.
- Green lentils naturally carry GOS (galacto-oligosaccharides), the same family found across many legumes, which puts them at moderate at ½ cup (92.5g) and pushes them into high territory as the serving increases.
- Boiling and draining canned or cooked lentils can help lower the overall load, since some GOS leaches into the cooking water, making a controlled portion more manageable.
Sticking to ½ cup (92.5g) and rinsing well lets you enjoy their earthy, hearty flavor without overdoing the GOS.
Per ½ cup (92.5g): 0.43g GOS.
Why green lentil (boiled) is rated moderate
Green lentils boiled from dried sit at moderate because of their GOS, the carbohydrate group that runs through legumes generally. The published serving data puts ½ cup (92.5g) at moderate and ⅝ cup (109g) at high, and the space between those two rungs is narrow: one extra spoonful over the side of a serving spoon covers most of it. That is why moderate here means a portion to measure and respect rather than a food to relax about. The rating is not about the lentil being difficult in some general way, it is about how quickly the GOS load climbs once the bowl gets generous.
What changes your risk
- The gap between the two rungs is small ½ cup (92.5g) is moderate and ⅝ cup (109g) is already high. Serving straight from the pot with a ladle makes that difference very easy to cross without noticing.
- The cooking water GOS is water-soluble, so boiling lentils in plenty of water and pouring that water away carries some of it off. Simmering them until the liquid is absorbed, or cooking them in stock that stays in the dish, keeps it all on the plate. Heat itself does not destroy GOS, no matter how long the pot runs.
- The canned form runs lower Canned lentils that are drained and rinsed under cold running water have their own record, and it is lower than the record for lentils boiled from dried. The rinse is the mechanism, so do it properly in a sieve until the water stops clouding.
- Stacking GOS in one meal A moderate food is the one most likely to tip a meal on its own. Putting these lentils alongside chickpeas, kidney beans, baked beans, soy beans, cashews or pistachios in the same sitting stacks the same subgroup and pushes the meal well past what any one component suggests.
- The onion and garlic around them Lentil salads and lentil soups are usually built on an onion and garlic base or a commercial stock, and those bring fructans that no amount of careful lentil portioning fixes. Garlic-infused oil, chives, leek leaves and the green tops of spring onions give the same savoury base without them.
Swaps
Because the moderate rating applies at ½ cup (92.5g), the sensible move is usually to let something else carry the bulk of the dish. Quinoa works in a cold salad where the lentils used to, firm tofu brings protein to a stew, and potato, polenta or rice fills out the plate. Carrots, green beans and zucchini bulk a braise without adding anything to the same subgroup, and walnuts or pumpkin seeds give a salad the bite the lentils were providing. Swapping to chickpeas, kidney beans or baked beans does not solve anything, since they carry the same GOS. If the lentil flavour is the point, canned lentils drained and rinsed are the lower running form of the same food.
How to lower the load
Measure cooked, not dry, since lentils roughly double in the pot and a dry measure tells you nothing useful about what lands in the bowl. Boil them in plenty of water rather than the exact amount they will absorb, and drain them properly, since the water you tip away takes some GOS with it. That also means cooking them in stock is the wrong move: the stock cannot be drained off, and most of it carries onion. Portion at the stove into ½ cup (92.5g) servings, dress them afterwards, and freeze the rest already measured. Eating out, a lentil salad or a bowl of lentil soup arrives in a quantity nobody has weighed, which is a different situation from a pot cooked at home.
Common questions
how much green lentils can you eat on low fodmap
½ cup (92.5g) is moderate and ⅝ cup (109g) is high. There is no lower tested serving for green lentils boiled from dried, so ½ cup (92.5g) is a portion to measure rather than a green light.
are green lentils high in gos
GOS is the subgroup driving their rating. At ½ cup (92.5g) the GOS load puts them at moderate, and at ⅝ cup (109g) it puts them at high.
does draining the cooking water lower the fodmaps in lentils
Some of it, yes. GOS dissolves in water, so boiling in plenty of water and pouring it away removes a portion of it. Cooking alone does not destroy FODMAPs, so simmering them dry or cooking them in stock leaves everything in the dish.
are canned lentils better than boiled green lentils
Canned lentils that are drained and rinsed have a lower record than green lentils boiled from dried, because the water-soluble FODMAPs leach into the canning liquid. The two forms are rated separately, so use the record for the form actually on the plate.
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Informational only, not medical advice. Individual tolerance varies. Talk to a healthcare professional or a dietitian for personal guidance.
References
- Fructan and free fructose content of common Australian vegetables and fruit. Muir et al. (2007), J. Agricultural and Food Chemistry 55(16):6619-6627.
- Measurement of short-chain carbohydrates in common Australian vegetables and fruits by HPLC. Muir et al. (2009), J. Agricultural and Food Chemistry 57(2):554-565.
- Quantification of fructans, galacto-oligosaccharides and other short-chain carbohydrates in processed grains and cereals. Biesiekierski et al. (2011), J. Human Nutrition and Dietetics 24(2):154-176.
- Dietary sorbitol and mannitol: food content and distinct absorption patterns. Yao et al. (2014), J. Human Nutrition and Dietetics 27(Suppl 2):263-275.
- FODMAPs: food composition, defining cutoff values and international application. Varney et al. (2017), J. Gastroenterology and Hepatology 32(Suppl 1):53-61. Supplies the low, moderate and high cutoffs used on this page.
Last reviewed September 22, 2026.