Many people starting a low FODMAP diet ask one thing right away: “Is garlic low FODMAP?” The short answer is no: garlic and onions contain fructans, a type of FODMAP that commonly triggers IBS symptoms like bloating, gas, or cramps.
But here’s the good news: temporarily eliminating them doesn’t mean eating bland food. As a dietitian specializing in IBS and the low FODMAP diet, I want my clients to enjoy a variety of delicious food without missing out on flavor.
Even though garlic and onions are high in FODMAPs, you can still enjoy rich flavor through smart substitutes and techniques. Let’s dive in!
Why Are Garlic & Onions IBS Triggers?
Garlic and onions are very concentrated sources of fructans, a type of oligosaccharides (the “O” in FODMAPs). Because our bodies lack the enzymes needed to break oligosaccharides down into single sugars, these carbohydrate chains move through the digestive system largely untouched.
When they reach the large intestine (colon) our gut bacteria – who do have the right enzymes – break them down, producing gas as a natural byproduct. In people IBS, who have a more sensitive digestive system, this gas production can trigger bloating, abdominal pain, and changes in bowel habits, including diarrhea or constipation. Fructans are one of the top 3 most common triggers for people with IBS.
Garlic & Onions: What You Can’t Eat (in Elimination)
When starting a low FODMAP diet, avoiding garlic, onions, and other members of the allium family can greatly reduce IBS symptoms.
High-FODMAP aromatics to avoid:
- Garlic cloves (fresh, chopped, minced)
- Onion bulbs (yellow, white, red, etc.)
- Garlic & onion powders
Shallots, leeks, and scallions (whole bulb)
These all contain fructans — oligosaccharides that are poorly absorbed and can trigger IBS symptoms.
Do You Need to Avoid Garlic & Onions Forever?
No, you don’t need to eliminate garlic or onions forever! A core principle of the low FODMAP diet is that elimination is temporary.
Once your symptoms improve, you’ll systematically reintroduce FODMAP groups (including fructans) to see what you tolerate. Many of my clients discover they can tolerate garlic, onion (or both) well, or at least in smaller amounts.
Can You Use Garlic & Onions on a Low FODMAP Diet?
While you are working on getting relief from your IBS symptoms with a low FODMAP diet, you can still use garlic and onions to give flavor to your dishes, with a few tricks!
Infuse flavor safely:
Fructans are not oil-soluble. That means you can sauté garlic or onions in oil to release their aroma and then completely remove the solids, leaving flavorful infused oil behind that’s low FODMAP.
Do NOT make broth or stock using garlic/onions.
Because fructans are soluble in water, they will leach into the liquid and raise the FODMAP content.
Flavor Substitutes You Can Use
There are many garlic and onion substitutes you can use during the elimination period of the low FODMAP diet.
✔ Garlic-Infused Oils
Create your own or choose a Low FODMAP Certified brand (the Monash FODMAP App is the best resource for approved brands). You can use it for stir-frying, dressings, making hummus, etc.
Tip: some “garlic flavored” oils contain garlic solids and are not low FODMAP. The safest ones are those with the Monash or FODMAP Friendly Low FODMAP logo.
✔ Green Parts of Alliums
The green tops of scallions (also called spring onions) and leeks are low FODMAP and add mild onion flavor. Chop the green parts and saute them in oil as you would when a recipe calls for onions.
✔ Garlic & Onion-Type Seasonings
Look for low FODMAP certified garlic salts, garlic scape powders, or onion replacements: they can deliver flavor without the fructans.
✔ Pickled products
Pickled onions and garlic have a small low FODMAP serving (check the Monash FODMAP App), and you can enjoy them during the elimination process.
✔ Herbs, Spices, & Aromatics
You can expand flavor using herbs and spices:
- Chives or garlic chives
- Asafoetida (use very sparingly)
- Ginger, lemongrass, citrus zest
- Fresh herbs (parsley, cilantro, thyme, rosemary)
Even though these don’t mimic garlic perfectly, they build complexity and depth of flavor.
How to Add Garlic & Onion Flavor on a Low FODMAP Diet – It’s a Wrap!
Although fresh garlic and onions are high in fructans and must be avoided during the elimination phase, you don’t need to give up their flavor.
You can still enjoy dishes with aromatic richness through infused oils, low FODMAP seasonings, and creative use of herbs and substitutes. This is just temporary and, once you identify your triggers, you can find your personal tolerance.
If you’d like help navigating the low FODMAP diet or figuring out your personal triggers, I’d love to help!
Get started by clicking on the button below and scheduling your complimentary IBS Clarity Call. We will review your symptoms and history and discuss the best next steps for you! You will come out of this call feeling relieved and hopeful that you can take control of your IBS.
Let’s work together
Book a free IBS Clarity Call today!
Published March 25, 2024. Updated February 23rd, 2026.
Antonella Dewell, MS, RDN | IBS Resolution Expert
Antonella Dewell is a registered dietitian and IBS specialist based in California. She has over 2 decades of experience working in clinical research at Stanford. Since 2018, she has been running a private practice. She helps people with IBS gain real, lasting relief from IBS symptoms in just 2-4 weeks without giving up all the foods they love, so they can stop feeling anxious around food and get back to fully enjoying food and life again.
