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!

Is a Low FODMAP Diet a Healthy Diet?

This is a question I get a low from my clients, worried that this may be just another fad diet. The low FODMAP diet was created by the researchers at Monash University in Australia to alleviate symptoms in people with Irritable Bowel Syndrome (IBS). It is currently considered the best dietary approach for this condition and several research studies have shown it is successful in 50-80-% of people with IBS. 

The answer to the question “is the low FODMAP diet healthy” depends on how it is implemented. Let me digress for a moment to a better-known diet concept, that of a vegan diet. Most people would think that the vegan diet is very healthy as it brings to mind pictures of environmentally friendly, animal-loving people feasting on salads, nuts, and tofu.

However, the definition of vegan diet verges on what it excludes – all animal products – rather than what it includes – plant-based foods. You could, in principle, be eating French fries, cookies made without eggs or butter and drink sodas and you would be considered a vegan. Although I have exaggerated with this example (at least I hope so!), you get the idea: having a bagel with jam for breakfast, a vegan burger on a white bun with lots of ketchup for lunch and a big plate of pasta with tomato sauce for dinner may be closer to what uninformed vegans may be eating and hardly be called a nutritious diet.

Going back to the low FODMAP diet, whether it is healthy or not depends more on what you include than what you exclude. The low FODMAP protocol teaches you to avoid high FODMAP foods (at least during the elimination phase) or minimize them according to tolerance once you have figured out your own personalized FODMAP diet. Many people, however, end up avoiding all high FODMAP foods long term either because they are afraid of re-challenging them or they don’t know that the low FODMAP diet is not supposed to be a life-long diet. And, especially during the elimination phase, they may get into a routine of eating the same few types of vegetables and fruit, or avoiding some foods, like legumes and dairy altogether.

The message I am trying to bring home here is that a poorly planned low FODMAP diet can lacking in important nutrients like calcium and B vitamins, and in fiber. Working with a dietitian who is an expert in the low FODMAP diet can help you avoid this common mistake. Here are a few questions you may ask yourself to get an idea about how healthy your low FODMAP diet is:

1. Am I eating enough fiber?

You don’t need a nutrition software to know whether you are eating enough fiber. Write down what you eat for a few days or a week and look back at your diary: are you eating vegetables at your main meals and at least one snack? Are you occasionally eating low FODMAP servings of canned lentils or chickpeas? Are you including some nuts and seeds? See my 5 Tips to Eat More Fiber on a Low FODMAP Diet for more ideas. 

2. Am I eating enough calcium?

Contrary to common belief, the low FODMAP diet is not a lactose-free diet. It is a low lactose diet and can include small portions of some hard cheese and cream cheese. Small amounts of lactose can be tolerated even by lactose-intolerant people. It is not a dairy-free diet either and you can eat plain lactose-free dairy freely. If you are avoiding dairy for other reasons (allergy to milk protein, ethical reasons, or you just don’t like them), there are many alternative calcium sources. And, yes, even vegans can eat enough calcium if they plan their diet well.

3. Am I eating the colors of the rainbow?

Is your diet white and red (gluten-free pasta and tomatoes) or do you choose vegetables and fruit with all the colors of the rainbow? This is an easy way to ensure you get the bounty of vitamins, minerals, and phytochemicals that vegetables and fruit have to offer. Chard, kale, spinach, carrots, red peppers, eggplant, kabocha and summer squash are just some of the vegetables that have either negligible or small amounts of FODMAPs and can be eaten freely or in fairly large portions. Fruit can be usually enjoyed in half-cup portions per meal or snack. In the spring and summer, strawberries, raspberries, blueberries and cantaloupe or honeydew are great low FODMAP choices, whereas in the fall/winter look for the citrus fruits and kiwi just to name a few.

If you answered yes to all these questions – great job! If you answered no to at least one of these questions, try some of the suggestions above and look at the Monash University Low FODMAP Diet App for guidance on foods and serving sizes.

Is a Low FODMAP Diet a Lactose-Free Diet? 5 Tips to Get Enough Calcium

It is a common misconception that a low FODMAP diet is a lactose or dairy free diet. It can be (if you have established that you are lactose intolerant or have a milk protein allergy) but it doesn’t have to.

A low FODMAP diet needs to be low in lactose as this is one of the short-chain carbohydrates that may trigger symptoms in people with Irritable Bowel Syndrome (IBS). If your body does not produce enough lactase – the enzyme that can split the lactose molecule into its singles sugars (glucose and galactose) – the unabsorbed lactose attracts water and travels to the large intestine undigested. There, our friendly bacteria ferment it, leading to unpleasant symptoms such as bloating, gas, stomach cramps, and diarrhea.

Calcium (together with vitamin D) is an important nutrient that helps build and maintain strong bones and teeth and has a role in keeping our muscles working (including our heart) and in helping nerves carry messages from the brain to other parts of our body. If you don’t get enough, we may become at risk for osteoporosis and fractures later in life. So, how can you make sure to get enough calcium on a low FODMAP diet? Here are a few tips.

1. Include some dairy products if you can

Small portions of certain dairy products, such as hard cheeses and cream cheese, contain minimal amounts of lactose and can be tolerated even by people with lactose intolerance. If you include lactose-free milk, yogurt, or kefir in your diet, you are less likely to be deficient in calcium. If you don’t, no worries: it is feasible to get enough calcium in your diet even without eating dairy. There are many other foods that are high in calcium.

2. Eat low FODMAP legumes

Beans and lentils contain good amounts of calcium. While on the elimination diet, you can only safely eat small portions of canned chickpeas and lentils. Soy beans and soymilk are high in FODMAP but edamame and firm tofu (drained) are excellent low FODMAP sources of calcium. If you have completed the re-challenge phase and know you tolerate them, you can experiment with other beans such as black, kidney and others and different kinds of lentils.

5. Go fishing

Well, you don’t really need to go fishing yourself. But if you are a pescatarian, you can enjoy canned fish with bones, especially salmon and sardines. The bones are small and soft and are edible, so throw them on a salad for an easy lunch.

3. Don’t forget the nuts and seeds…

Almonds and brazil nuts are high in calcium even at the low FODMAP serving of about 10 nuts. Nuts and seeds are also used to make non-dairy milk. In addition to almond milk, other low FODMAP varieties are hemp and macadamia. Although most kinds of non-dairy milk are fortified with calcium (and vitamin D), check the labels as some are not. I talked previously about chia seeds as a fiber superstar but this tiny seed is also high in calcium. If you haven’t yet, check out my recipe for Cocoa Chia Pudding (it has almond milk too!).

4. …and the vegetables!

Kale does not need a PR campaign as a superfood (one of its many benefits is that it is high in calcium) but the less-known Bok Choy certainly does. The baby variety is very easy to handle and prep fast. See this delicious, easy recipe for my Colorful Asian Stir-fry (guess what? It also has tofu!).

If you are not sure you are meeting your calcium needs, ask for the help of a dietitian who is versed in the low FODMAP diet. He/she can help you maximize your intake without risking unpleasant symptoms.

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Colorful Asian Stir-Fry


1 tablespoon high sunflower or avocado oil

8 oz. firm or extra firm tofu, cut into cubes

1-inch piece ginger, minced (about 2 teaspoons)

2 cups chopped (5 oz.) baby Bok Choy, stems and leaves separated, chopped

1 medium red or orange bell pepper (6 oz.), thinly sliced

1 medium carrot (2 oz.), thinly slices on the diagonal

1 tablespoon oyster sauce*

½ teaspoon toasted sesame oil

½ teaspoon sesame seeds (optional)

*gluten-free, if following a gluten-free diet


1.     Heat a large heavy-bottomed skillet or wok on medium-high heat, add 1 teaspoon of the oil and the tofu. Let it cook for about 3 minutes or until browned, then turn the tofu pieces with a spatula and let them brown (2-3 minutes). Set aside.

2.     Add the remaining oil to the skillet or wok and, when hot, add the ginger. After 30-60 seconds, add the Bok choy stalks, bell pepper, and carrot (make sure the skillet is wide enough so not to overcrowd it or the vegetables will steam instead of stir-fry). Cook for 1- 2 minutes, stirring often until vegetables are crisp-tender.

3.     Add the baby Bok choy leaves and stir-fry for another 30-60 seconds, or until just wilted.

4.     Add oyster sauce and tofu and stir until the vegetables and tofu are coated. Turn the heat off and add the toasted sesame oil.

5.     Serve on top of brown rice and sprinkle with the sesame seeds, if desired.

Yield: 2 servings

Storage: Store in an air-tight container in the refrigerator for up to 3 days.

Author: Antonella Dewell, Registered Dietitian Nutritionist & Natural Chef