Traditional pho is not low FODMAP as typically prepared. The core problem is the broth: classic pho simmers whole onions (and often garlic) for hours, and the FODMAPs in those ingredients dissolve directly into the liquid. However, pho can absolutely be made low FODMAP at home with a few ingredient swaps, and you can make smarter choices when ordering at restaurants.
Why Traditional Pho Broth Is High FODMAP
A standard pho recipe calls for two large halved onions simmered in the broth alongside ginger, star anise, cinnamon, cardamom, cloves, and coriander seeds. Many versions also include garlic. You might assume that removing the onion pieces before serving solves the problem, but it doesn’t. Monash University, the leading FODMAP research institution, has confirmed that the fructans in onion and garlic are water-soluble. When you simmer them in liquid, those fructans leach directly into the broth. Pulling the solids out afterward makes no difference because the FODMAPs are already dissolved in every spoonful.
This is the single biggest issue with pho for anyone on a low FODMAP diet. The broth is the soul of the dish, and in its traditional form, it’s essentially onion-infused water seasoned with spices.
The Spices, Noodles, and Meat Are Fine
The good news is that almost everything else in a bowl of pho is naturally low FODMAP. Monash University lists star anise, cinnamon, cloves, cardamom, and ginger as low FODMAP at typical seasoning amounts. These are the spices that give pho its distinctive warm, aromatic flavor, and none of them need to be avoided.
Rice noodles, the standard noodle in pho, are naturally low FODMAP. Plain beef (brisket, flank, eye of round), chicken, and seafood are all FODMAP-free when prepared without high FODMAP marinades or sauces. The common garnishes are also safe: bean sprouts, Thai basil, fresh coriander (cilantro), mint, chili, and lime are all low FODMAP. Fish sauce, the condiment typically served alongside, is low FODMAP as well.
So the dish itself is mostly friendly. It’s really just the broth base that creates the problem.
Making Low FODMAP Pho at Home
The most reliable way to enjoy pho on a low FODMAP diet is to make the broth yourself. The key substitution is replacing whole onions and garlic with alternatives that deliver similar flavor without the fructans.
Fructans are water-soluble but not oil-soluble. This means you can infuse oil with onion or garlic flavor, then discard the solids and use that oil as a base. The flavor transfers to the oil, but the FODMAPs stay behind in the discarded pieces. Start your broth by gently heating sliced onion or garlic cloves in oil until fragrant, remove the pieces completely, and then build your broth from that flavored oil.
Other substitutions that work well:
- Asafoetida powder: A spice that delivers an oniony, garlicky flavor. Monash has lab-tested it and confirmed a low FODMAP serving size of about 1/4 teaspoon (2 grams). For best results, bloom a small pinch in warm oil before adding your liquid, similar to how you’d use curry powder.
- Garlic scapes (garlic shoots): The green shoots that grow from garlic bulbs. They have a mild garlic flavor and are low FODMAP up to about 30 grams. You can chop them the way you would scallion greens.
- Green parts of scallions: The dark green tops provide a mild onion taste without the concentrated fructans found in the white bulb.
Once you’ve handled the onion and garlic issue, the rest of the recipe stays the same. Toast your star anise, cinnamon, cardamom, cloves, and coriander seeds. Char your ginger. Simmer beef or chicken bones for depth. You’ll end up with a broth that tastes remarkably close to the original.
Watch Out for Commercial Pho Bases
If you’re tempted to use a store-bought pho concentrate or bouillon to save time, check the ingredients carefully. Commercial pho bases frequently contain onion juice concentrate, onion powder, garlic powder, or “natural flavors” that may be derived from high FODMAP sources. A typical commercial pho concentrate lists ingredients like sugar, salt, anchovy extract, ginger, spices, and then onion juice concentrate further down the list. Even small amounts of concentrated onion or garlic can be enough to trigger symptoms.
Look for products that specifically advertise as FODMAP-friendly, or stick to making your own bone broth seasoned with the safe spices listed above.
Ordering Pho at a Restaurant
Restaurant pho is the trickiest situation because the broth is almost certainly made with onions and possibly garlic, and there’s no way to remove those FODMAPs after the fact. Monash University’s general guidance for eating out with Asian food is to avoid sauces and heavily flavored, rich dishes and lean toward plain meat, fish, and rice noodle dishes with fresh vegetables.
Your practical options at a Vietnamese restaurant:
- Ask about the broth: Some restaurants may prepare a lighter broth or be willing to share what goes in. This is worth asking, though most traditional kitchens will have onion in the base.
- Limit your portion: If you’re in the reintroduction phase of the low FODMAP diet and know your personal tolerance for fructans, a smaller serving of broth may be manageable. Some people tolerate small amounts of fructans without symptoms.
- Consider alternatives on the menu: Rice vermicelli bowls (bún) with beef, chicken, or shrimp often come with fresh salad vegetables and peanuts on top, served with fish sauce on the side. Ask for no onion. These dishes tend to have less FODMAP exposure than a broth-based soup.
If you do order pho, the garnish plate is your friend. Load up on bean sprouts, Thai basil, lime, and chili. Skip any fried shallots or hoisin sauce that might be offered, as hoisin often contains garlic and onion. Sriracha-style hot sauces may also contain garlic, so check before adding.
Portion Size Still Matters
Even with a homemade low FODMAP broth, keep an eye on your total rice noodle portion. Rice noodles are low FODMAP at a standard serving, but very large amounts of any starchy food can contribute to digestive discomfort in sensitive individuals. A typical restaurant bowl of pho can contain a generous pile of noodles, so if you’re newly on the elimination phase, start with a moderate amount and see how you respond.
The bottom line: pho’s flavor profile is built on ingredients that are almost entirely FODMAP-friendly. Onion in the broth is the one major obstacle, and it’s completely solvable when you cook at home. With garlic-infused oil, asafoetida, or garlic scapes standing in, you can make a bowl that’s both authentic-tasting and gut-friendly.