What Makes a Food Low FODMAP?
FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols — five families of short-chain carbohydrates that are poorly absorbed in the small intestine. In people with IBS they draw water into the bowel and are rapidly fermented by gut bacteria, producing the gas, bloating, cramping, urgency and irregular bowel habits that define the condition.
A food is classified as "low FODMAP" when a normal serving contains less of these carbohydrates than the threshold most people with IBS tolerate. That is why nearly every entry on this page comes with a portion. Zucchini is low FODMAP at ¾ cup and high FODMAP at two cups. Avocado is safe at one-eighth and a trigger at half. Very few foods are unlimited, and very few are banned outright — dose is what matters.
The Five FODMAP Groups at a Glance
- Fructans (oligosaccharides): wheat, rye, barley, garlic, onion, inulin/chicory root. The most common trigger by far.
- GOS (oligosaccharides): legumes, beans, cashews, pistachios, soy milk made from whole beans.
- Lactose (disaccharide): cow, goat and sheep milk, yogurt, ice cream, soft cheeses.
- Excess fructose (monosaccharide): apples, pears, mango, watermelon, honey, agave, high-fructose corn syrup.
- Polyols: sorbitol and mannitol in stone fruit, blackberries, cauliflower, mushrooms, and the sugar-free sweeteners ending in -ol.
Most people are only sensitive to two or three of these groups. That is the entire point of the reintroduction phase described further down — the strict list below is a temporary diagnostic tool, not a permanent way of eating.
