Oats

Why oats is rated low

Rolled oats are low FODMAP at about ½ cup (50g) weighed dry, which is a full breakfast bowl once they swell, and that is a large part of why they are such a dependable breakfast on this diet. The margin above that is narrow, though. At larger portions the level is moderate and at much larger portions it is high, driven by GOS, so a noticeably heavier scoop is enough to tip the bowl. The serving applies to rolled oats weighed dry, and the rating says nothing about the honey, dried fruit or milk that usually arrives with the bowl.

What changes your risk

• Serving size, weighed dry About ½ cup (50g) of rolled oats, weighed dry, is low, larger portions are moderate and much larger portions are high. Oats swell a great deal, so judging the portion after cooking is unreliable.
• Rolled versus quick oats Quick oats are cut finer and pack more densely into a cup, so a half cup scoop of quick oats is not the same as a half cup of rolled. Check which kind is in the pantry and weigh rather than scoop if you can.
• What goes into the bowl GOS builds as the oat portion grows, and the toppings bring their own load on top. Honey, dried fruit, apple, pear, cashews and pistachios each add to it, while lactose free milk or lactose free yoghurt, strawberries, blueberries, raspberries, walnuts, pecans and maple syrup fill the same roles.
• Muesli and granola are not plain oats They are oats plus dried fruit, honey, inulin or chicory root fibre and often cashews or pistachios, so a cereal built on oats can behave very differently from the oats themselves.
• Cooking does not change the rating Stovetop porridge, microwaved oats, overnight oats and baked oats all sit wherever the dry amount you weighed belongs. Soaking and heat do not break FODMAPs down.

What else works

If you want to rotate breakfasts rather than replace oats, quinoa, polenta, rice and buckwheat all make a warm morning bowl, and gluten free bread, eggs, lactose free yoghurt with strawberries or blueberries, and a handful of walnuts or pecans cover the rest of the morning. For sweetening, maple syrup, rice malt syrup and table sugar do the job that honey usually does. The things people assume are the same but are not: muesli and granola loaded with dried fruit, honey and cashews, wheat based cereals and biscuits, oat milk, which is a separate food with its own rating, and anything listing inulin or chicory root fibre among the first ingredients.

How to keep it low

Measure the oats dry before they go anywhere near liquid, since that is the only point at which the portion is honest, and with moderate not far above the low serve, a kitchen scale beats a cup measure. Buy plain rolled oats with oats as the single ingredient rather than flavoured sachets, which are mostly sugar and dried fruit pieces by weight. Overnight oats work well here because you build them in a jar the night before, which fixes the portion before you are hungry and half awake. If the bowl feels small, add volume with things that are low rather than more oats: lactose free milk or yoghurt, a scoop of strawberries or blueberries, a spoon of peanut butter, a few walnuts, and maple syrup instead of honey.

Common questions

are oats low fodmap

Yes. Rolled oats are low at about ½ cup (50g) weighed dry. At larger portions they are moderate and at much larger portions they are high, from GOS, so the size of the bowl is what matters.

how much oats can i eat on a low fodmap diet

The low serve is about ½ cup (50g) of rolled oats, weighed dry before cooking. A larger portion is moderate, so it is worth weighing rather than heaping the scoop.

is oat milk low fodmap

Oat milk is a different product with its own rating, so the serve for oats does not carry over to it. Lactose free milk is the straightforward option for a bowl of porridge.

can i eat overnight oats on the elimination phase

Yes, built from about ½ cup (50g) of plain rolled oats weighed dry before soaking. Keep the toppings low as well, since honey, dried fruit and ordinary milk are usually what lifts the bowl.