Key takeaways
- Sweet potato is low FODMAP at 70 g (roughly half a small sweet potato).
- At 100 g and above, mannitol content rises into the moderate/high range.
- This is a meaningful portion limit — a typical baked sweet potato weighs 200–250 g.
- Regular white potato has no meaningful FODMAP limit — a useful swap when you want a larger portion.
Sweet potato is nutritious and delicious, but it comes with a genuine portion caveat that catches many people out. A standard restaurant or home serving of sweet potato often well exceeds the low-FODMAP limit.
FODMAP status at a glance
- —Sweet potato, 70 g (roughly half a small potato): low FODMAP
- —Sweet potato, 100 g: moderate FODMAP — mannitol approaching limit
- —Sweet potato, 200 g (a standard baked sweet potato): high FODMAP
- —Sweet potato fries (restaurant portion): likely high FODMAP
Mannitol is a sugar alcohol (polyol) that is poorly absorbed in the small intestine. It draws water into the gut and ferments in the colon — contributing to both diarrhoea and bloating.
When to swap for regular potato
Using sweet potato within limits
- —Add 70 g of diced sweet potato to a stir-fry or soup for sweetness and colour
- —Serve a small portion alongside a main rather than as the bulk carbohydrate
- —Pair with regular potato in dishes requiring a larger carb volume
- —Roast and weigh before serving — it shrinks during cooking
References
- 1.
