My Guide to Choosing Soy Foods on a Low FODMAP Diet

Soy foods can be an important source of protein and other nutrients for vegetarians and vegans and a way to break away from the routine of eating animal protein for everyone else. Even Monash University recently recognized the importance of eating less animal protein by starting a Meat Free Week campaign on Instagram and posting vegetarian a recipe a day for a week on their blog.

Soy beans are indeed a source of FODMAPs - mostly galacto-oligosaccharides (GOS) and some fructans - and not allowed during the elimination phaseSoy milk that is made from soy beans (and soy yogurt, which is made from soy milk) is also high in FODMAPs, as it is made by grinding the beans and water together. Incidentally, there is a type of soy milk made from soy protein which is low in FODMAPs. It is popular in Australia but here in the US it is not as easy to find. The only brand I came across is 8th Continent but all their varieties are high in sugar and one of them also contains inulin.

However, many of the products made from soy beans become low FODMAP because of what happens during the food processing. As I described in a recent blog article, it turns out that the FODMAPs in soy are soluble in water. Hence, any technique that involves soaking the soybeans in water and straining them will allow the FODMAPs to leach into the water and considerably lower the FODMAP content of that food. This is the case with firm tofu. On the other hand, silken tofu is not drained and retains all the water and the FODMAPs. 

Another food processing technique that lowers FODMAP content is fermentation. This explains why plain tempeh (made from fermenting soy beans) is low in FODMAPs. Some varieties also have grains like rice or millet but most are free of wheat/gluten. Watch out for added high FODMAP ingredients like garlic, onions, or celery. See my Indonesian Tempeh Randang recipe for a tasty way to eat this less-known and appreciated soy food.

A second consideration when choosing soy products is that GOS and fructans are fibers, and the foods that are lower in fiber are also lower in FODMAPs. Immature soybeans (edamame) are an example. Monash University tested them and found them suitable in small amounts.

Soy burgers or meat substitutes have not been tested but most likely are high in FODMAPs as they may contain the fibers from soybeans. Soy protein powder may be low in FODMAPs depending on how it is processed. It is best to avoid it during the elimination phase as its FODMAP status is unknown.

Soy lecithin and soybean oil are not a source of FODMAPs and are ok. Soy sauce has been tested and found to be low in FODMAPs.

In summary, use this guide to navigate the soy aisle and don’t be afraid in experimenting with soy foods. 


  • Tofu (firm or extra firm)

  • Plain Tempeh (no extra high FODMAP ingredients)

  • Edamame

  • Soybean oil

  • Soy sauce


  • Soy beans

  • Soy milk (made from soy beans)

  • Soy yogurt

  • Silken tofu

  • Soy burgers/meat substitutes

  • Soy protein powder

Check out the Monash University App for appropriate serving sizes.

If, after completing the re-challenge phase, you find that you can tolerate GOS and fructans, you can experiment with the high FODMAP soy foods.

Tempeh Randang


2 inch- stalk of lemongrass (from the bottom white part), roughly chopped
2-inch piece of ginger, peeled, roughly chopped
2 tbsp water

1 tbsp sunflower seed or canola oil
8 ounces/225 g tempeh, cut into ½-inch pieces

½ lb. small red potatoes, scrubbed and cut into ½-inch cubes
¾ tsp ground fennel seed
½ tsp ground cardamom
¼ tsp ground cloves
½ cinnamon stick (about 2 inches)

1 small can (5.46 oz/160 ml) unsweetened coconut milk
½ cup water
½ tsp salt
A few grinds of black pepper 


1. Blend the lemongrass stalk and ginger with 1 tablespoon of the water. Scrape the sides of the blender, add the additional tbsp of water and blend until you have a paste (it will be a rough paste, due to the fiber in the lemongrass, but that’s ok).

2. In a nonstick skillet, heat the oil over medium high heat and sauté the tempeh until browned, about 3-5 minutes per side. Add the dry spices, cinnamon stick, the lemongrass-ginger paste and a little water, and sauté for 2 more minutes. Add the potato, coconut milk and water. Bring to a boil, lower the heat, cover, and simmer until the potato is tender, about 5 minutes, stirring occasionally.

3. Remove from the heat, season with the salt and pepper, and serve over red or brown rice.  


4 servings


Store in an airtight container in the refrigerator for up to 4 days.


Antonella Dewell, Registered Dietitian Nutritionist and Natural Chef 

5 Ways to Lower the FODMAP Content of Foods: Effect of Food Processing Techniques

Earlier this year, new research from Monash University highlighted the tremendous effect that some common food processing techniques can have on the FODMAP content of food. These are very useful “tricks” to know when preparing of choosing foods. They allow you to lower the content of some foods that otherwise would be out of a low FODMAP diet (at least during the elimination phase) and increase the variety of your diet.

5 Ways to Lower the FODMAP content of some high-FODMAP foods:

1. Boiling and straining

Some FODMAPs (fructans and galacto-oligosaccharides or GOS) are water soluble and they leach out in the water every time you boil and strain a food. The research showed that boiling dried red lentils and kidney beans decreased the FODMAP content more and more for every 5 minutes of boiling up to 30 minutes. And straining the boiled legumes reduced it even more. The ultimate boiling process is the one used for canning. There is the advantage that, while sitting in the liquid in the can, the beans/lentils leach out more FODMAPs. Tip: choose canned varieties during the elimination phase (chickpeas and lentils are low enough to be rated “green” by the Monash University App). Then, experiment with cooking other dried beans and lentils once you have passed the oligo-saccharide challenge.

2. Pressing and straining

This refers mostly to the making of tofu.  As firm tofu is made by coagulating the soy milk, then pressing and straining the liquid, it is low in FODMAPs. Conversely, silken tofu is made by coagulating the soy milk in the package it is sold in, where all the liquid (and FODMAPs) remain. Tip: buy only firm or extra firm tofu, strain it from the liquid it is floating in, and pat it dry before using.

3. Fermentation

This is where things get tricky: depending on the food, fermentation can either lower or increase the FODMAP content. Where fermentation helps is in the making of bread. If you know a bit about the low FODMAP diet, you know that wheat is not included, as it is high in fructans and GOS. When bread is made using a sourdough culture, however, the microorganisms in the culture feed on them, and lower the overall FODMAP content of the bread. On the other hand, fermenting raw cabbage to make sauerkraut or kimchi increases the content of the polyol mannitol, as this is a by-product of the fermentation. Tip: if you want to enjoy wheat bread while on a low FODMAP diet (and you don’t need to avoid gluten due to celiac disease), you can have small amounts of true sourdough bread. However, avoid sauerkraut and kimchi, unless you have passed the polyols challenge, and enjoy small quantities of regular cabbage.

4. Pickling

For the first time, this research showed that pickling onions, garlic, and beets reduced the FODMAP content by more than 80%, so much to make onions and beets “green”- rated foods. This is due to the fermentation that occurs when vegetables are immersed in brine, or to the lowering of the pH when they are immersed in vinegar. Tip: if you miss these vegetables, buy pickled varieties and check out the Monash University App for appropriate serving sizes.

5. Activating

This mostly pertains to nuts. Activating involves soaking the nuts in water for a minimum of 12 hours, then dehydrating them at low temperatures. The research showed that activated cashews and pistachios, which are the nuts highest in FODMAPs, had significantly lower FODMAP content than their raw counterpart, possibly because the FODMAPs leached out in the water. The decrease in FODMAP content was not sufficient to rate them “green” at a standard serving but a very small serving of cashews was rated green. Tip: buying activated nuts such as almonds, which are low in FODMAP at small serving sizes, may allow you to eat more of them. After you have completed the re-challenge phase, you can experiment and see how much of these nuts (or perhaps even cashews or pistachios) you can eat.

P.S. Thanks to all my readers! My blog recently was selected by Feedspot as one of the Top 50 Low Fodmap Blogs on the web. This is the most comprehensive list of Top 50 Low Fodmap Blogs on the internet.

4 Ingredients to Lower Cholesterol: The Portfolio Diet and How to Adapt It to a Low FODMAP Diet

I was sitting in the last row of a crowded shuttle bus that was taking me from my hotel to Loma Linda University, where I was attending the International Congress on Vegetarian Nutrition, when I noticed I was elbow-to-elbow with one of my nutrition research heroes: Dr. David Jenkins. I couldn’t believe it! My colleague and friend sitting next to me still remembers how excited I was – and teases me about it.

That day Dr. Jenkins would speak about the results of his recently published research on a new dietary approach that lowered blood cholesterol as much as a statin (cholesterol-lowering) drug: the Portfolio Diet. What are the highlights of this research?

  • This diet put together all the foods that, individually, had shown to lower LDL cholesterol in previous research into a “package” named the Portfolio Diet (vegetarian)

  • In the first study, research participants on the Portfolio Diet arm were fed all their food for 4 weeks

  • The average LDL (bad) cholesterol in this group decreased by 29%

  • This change was similar to that observed in the comparison group: participants took a statin drug while eating a low saturated fat diet and dropped their LDL by 31%

  • In a follow-up study, participants did not get their food but were taught the Portfolio Diet and the drop in LDL cholesterol was not as dramatic but still clinically significant (13-14%).

  • In this study, there was a range of response: the better the participants were able to stick to the diet, the bigger their cholesterol reduction (about 20%).

This was not a prisoners’ diet, but a palatable vegetarian diet: the participants liked it and felt it kept them full.  So, what does it look like? It has 4 main ingredients:

  1. Soy-based foods such as soy milk, tofu, and soy-based meat alternatives (instead of meat, poultry or dairy)

  2. Soluble fiber from grains like oats and barley, beans/lentils, certain vegetables (eggplant, okra, Brussels sprouts), and a daily serving of psyllium fiber

  3. Plant sterols as enriched margarine, fortified orange juice or yogurt, or taken in capsule form as a supplement

  4. Nuts. The research studies used almonds but other tree nuts can be substituted.

How much you need to eat of each of these components depends on your daily caloric intake. A registered dietitian can help you figure out how many grams of soy proteins, soluble fiber, plant sterols and nuts you need per day, and translate these into real foods and menu ideas.

If you are following a low or modified FODMAP diet, this plan can be easily fitted into your diet. First, I would advise you to complete the elimination and re-challenge phases of the diet. For starters, it is best to focus on one goal at a time, and first alleviate your IBS symptoms, then tackle the high cholesterol issue. The low FODMAP diet is very challenging to learn and you might be overwhelmed by having to change too many aspects of your diet at once.

Second, you will be in a much more relaxed state of mind, feel better, and be ready for a new challenge, once your symptoms have subsided. And finally, you will know which high FODMAP foods you can tolerate and expand the variety of foods you can eat. For example, you will be able to eat larger servings of okra, Brussels sprouts and beans/lentils if you have passed the oligo-saccharide challenge. If this is a problematic FODMAP category for you, you can focus on lower FODMAP sources of soluble fiber like oats, chia seeds, small servings of broccoli and sweet potato, and psyllium fiber.

Whether you have IBS or not, make sure you talk to your doctor if you decide to try this diet. This may not replace the need for medication for everyone but be a complementary therapy and perhaps allow you to lower the dosage of medications, if you are already taking them. Also, your doctor might know (or remember) about the Portfolio Diet. When I told my doctor how I was able to replicate the results of this research and she could see the 35% drop in LDL (bad) cholesterol in my new lab test results, she asked: do you mind if I use this with my patients? Of course, I answered: please, do!