Nearly all pure cooking oils are low FODMAP. Because FODMAPs are types of carbohydrates, and oils are made entirely of fatty acids with no carbohydrates or protein, they simply don’t contain the sugars that trigger digestive symptoms. That means olive oil, coconut oil, canola oil, avocado oil, sesame oil, and most other pure oils are safe choices during the elimination phase of a low FODMAP diet.
Why Oils Are Naturally Low FODMAP
FODMAPs are short-chain carbohydrates: specific sugars like fructose, lactose, and fructans that pull water into your intestines and ferment quickly in your gut. Pure fats don’t contain any of these sugars. When a seed, nut, or fruit is pressed into oil, the carbohydrates and proteins stay behind in the pulp. What you’re left with is pure fat, which your body processes through a completely different pathway than carbohydrates.
This is why even oils from high FODMAP sources can be safe. Avocado flesh, for example, becomes moderate to high FODMAP at larger servings. But avocado oil contains none of those problematic sugars because they weren’t fat-soluble enough to make it into the final product.
Oils Confirmed as Low FODMAP
The following oils are all low FODMAP in standard cooking amounts:
- Olive oil (including extra virgin)
- Coconut oil
- Canola oil
- Avocado oil
- Sesame oil (including toasted)
- Sunflower oil
- Peanut oil
- Vegetable oil
- Rice bran oil
- Safflower oil
- Flaxseed oil
- Walnut oil
- Hempseed oil
- Almond oil
Ghee (clarified butter) also falls into the safe category. The clarification process removes nearly all the milk solids, including the lactose that makes regular butter a potential concern for some people.
Garlic and Onion Infused Oils
This is the detail that surprises most people on a low FODMAP diet. Garlic and onion are two of the highest FODMAP foods, yet garlic-infused and onion-infused oils can be perfectly safe. The reason comes down to chemistry: the FODMAPs in garlic and onion are fructans, and fructans are water-soluble, not fat-soluble. When garlic cloves sit in oil, their flavor compounds dissolve into the fat, but the fructans stay trapped in the garlic itself. You get the taste without the trigger.
There’s an important distinction here, though. A properly infused oil has had the garlic or onion removed after infusing. If you see pieces of garlic or onion still sitting in the bottle, those solids can continue releasing fructans, especially if any water is present. For the safest option, look for commercially produced infused oils that carry the Monash University Low FODMAP Certified logo, which means the product has been lab-tested and falls below FODMAP cutoff levels. Cobram Estate, for example, produces a range of infused extra virgin olive oils that have received this certification.
If you’re making garlic-infused oil at home, heat the oil gently with whole peeled garlic cloves, then strain the garlic out completely before using or storing the oil. The same process works for onion. Just don’t leave the solids in the oil.
Where Oils Can Get Tricky
Plain oils are straightforward, but flavored, seasoned, or blended oil products deserve a closer look at the ingredient list. A “garlic oil” that contains garlic powder or garlic extract is not the same as a garlic-infused oil. Garlic powder is ground-up garlic, fructans and all. Similarly, stir-fry sauces, marinades, and seasoned cooking sprays often contain onion powder, honey, high fructose corn syrup, or other high FODMAP additives blended into an oil base.
The rule is simple: if the label lists a high FODMAP ingredient as an actual component (not just as a flavor infused into the oil), treat it as high FODMAP. “Natural flavors” on a label is vague enough to warrant caution, since it could include concentrated garlic or onion extracts.
Serving Sizes and Practical Limits
While oils themselves don’t contain FODMAPs, some low FODMAP guidelines still suggest a serving size of about one teaspoon for cooking and salad oils. This isn’t because the oil becomes high FODMAP at larger amounts. It’s because large quantities of fat can trigger digestive symptoms on their own, especially in people with IBS. Fat slows gastric emptying and can increase intestinal contractions, which may cause bloating or discomfort regardless of FODMAP content.
In practice, most people on a low FODMAP diet use oils freely in normal cooking quantities (a tablespoon or two for sautéing, a drizzle on salad) without issues. If you notice that high-fat meals consistently bother you, reducing oil portions is worth trying as a separate variable from your FODMAP elimination.
Choosing the Right Oil for Cooking
Since so many oils are safe, the choice really comes down to flavor and how you’re cooking. Every oil has a smoke point, the temperature at which it starts to break down and produce bitter flavors and harmful compounds. Matching your oil to your cooking method makes a bigger difference in your food than which specific oil you pick.
For high-heat cooking like frying, stir-frying, or roasting above 400°F, rice bran oil is a standout with a smoke point around 490°F. Avocado oil, refined coconut oil, and light (refined) olive oil also handle high heat well. For medium-heat sautéing, regular olive oil, canola oil, peanut oil, and sesame oil all work. For salad dressings, dips, and finishing drizzles where the oil won’t be heated, extra virgin olive oil, walnut oil, flaxseed oil, and toasted sesame oil offer the most flavor. Unrefined sunflower oil has a much lower smoke point (around 225°F) and isn’t a great choice for frying, though the refined version handles heat better.
Nut-based oils like walnut and almond oil are low FODMAP because the pressing process leaves the carbohydrates behind, just like other oils. This holds true even though whole nuts have FODMAP limits (generally fewer than 10 per serving). The oil and the whole nut are different products with different compositions.