Low FODMAP Diet Scientifically Proven to Improve IBS

Low FODMAP Diet: Scientifically Proven to Improve IBS

This article was written by dietetic intern Rachel Evans and edited by Katie Dodd, MS, RDN, CSG, LD, FAND

  • Do you have ongoing problems with stomach pain, bloating, excessive burping, gas, diarrhea or constipation?
  • Have you been diagnosed with Irritable Bowel Syndrome?
  • Have you noticed your symptoms get worse after eating certain foods?

If you answered “yes” to these questions, the low FODMAP diet might be good for you to try. Of course, before starting any new diet, it is important to talk to your Doctor or Registered Dietitian to see if this is a good treatment plan for you.

Low FODMAP Diet

The low FODMAP diet was designed to help people find relief from digestive issues through eliminating and then reintroducing specific foods. By doing this, the low FODMAP diet can help pinpoint which foods are tolerated and which ones are causing trouble.

This blog will detail how to implement a low FODMAP diet safely as well as some meal ideas and tips for success; but first we will learn a little bit more about irritable bowel syndrome…

What is IBS

What is Irritable Bowel Syndrome?

Irritable Bowel Syndrome (IBS) is a chronic functional disorder of the gastrointestinal system. The symptoms of IBS vary from person to person but often include bloating, gas, diarrhea, constipation or a combination of both. There is no known cause, but genetics, diet, lifestyle, infection or a change in intestinal bacteria may play a role (1).

The severity and frequency of symptoms of IBS is different from person to person. However, there are symptom “triggers” that many people have in common.

What are common IBS triggers?

Both stress and diet can have a big impact on IBS symptoms.

Stress can wreak havoc on your body. Nerves extend from the brain down into the GI tract. When a person is experiencing stress, the brain communicates this through these nerves. As a response, the GI tract is stimulated, and digestive issues may worsen (2).

Diet is a big factor for most people who have IBS. Eating large meals and eating specific types of foods often cause a flare of symptoms. (2) One thing “trigger” foods often have in common is that they contain “short chain carbohydrates” (5). We’ll learn more about these soon!

What makes up our food?

FODMAPs foodsGiven that diet is a major factor in IBS, it is important to understand what is in food. And, particularly what nutrients are more likely to aggravate symptoms.

The foods we eat are comprised of three types of nutrients: proteins, fats and carbohydrates.

FODMAPs are only found in carbohydrates- not proteins or fats. Therefore we will focus on learning more about carbohydrates and how they are digested and absorbed.

Carbohydrates

Carbohydrates, also known as sugars and fibers, are the biggest source of energy for your body. There are several different kinds of carbohydrates. Some are comprised of single sugar molecules while others are comprised of multiple sugar molecules which we will call “sugar chains” (3).

As mentioned earlier, “trigger” foods often contain “short-chain carbohydrates”.  These troublemakers are referred to as FODMAPs and this is why a low FODMAP diet can help relieve symptoms! Let’s dig deeper…

What does FODMAP stand for?

FODMAP is an acronym for different types of foods. It stands for:

  • Fermentable- Easily turned into gas
  • Oligosaccharides – Sugar chains that contain 3 or more sugar molecules linked together
  • Disaccharides– Two sugar molecules linked together
  • Monosaccharides– single unit sugars
  • And
  • Polyols– sugar alcohols

How do FODMAPs Cause Symptoms?

FODMAPs contribute to IBS symptoms in these ways (5):

  • They are poorly absorbed in the small intestine– Unabsorbed FODMAPs continue down the digestive tract into the colon where lots of bacteria live.
  • They are bacteria’s favorite food– Bacteria feed on FODMAPs and quickly turn them into gas, which may cause abdominal bloating and discomfort.
  • They act as a sponge -FODMAPs draw an excessive amount of water into the colon which can lead to watery stools.

All of this can cause significant discomfort in those with IBS.

Digestion and Absorption of Sugar Chains

To understand why FODMAPs can be a problem, we need to understand how sugar chains are digested and absorbed.

Sugar chains cannot be absorbed into the body unless they are first broken down into single sugar molecules. This is a process called digestion. Enzymes in the intestine work to break down your food. Absorption happens when the digested foods pass through the intestinal membrane into the blood stream for your body to use as energy (3).

Why Aren’t FODMAPs Absorbed Well?

Here is a quick description of each type of FODMAP and an explanation of why they may not be well absorbed.

  • Oligosaccharides – Fructans are one type of oligosaccharide and are found in wheat, onions, asparagus and garlic. Galacto-oligosaccharides, another type of oligosaccharide is found in beans and legumes. Humans do not have enzymes that can break down these chains so these cannot be absorbed (3).
  • Lactose– Lactose is a disaccharide, made up of glucose and galactose. Lactose intolerance occurs when enzyme activity to break it down is lacking. When lactose is not broken down it cannot be absorbed. (3)
  • Fructose– Fructose is a monosaccharide. Although it is single sugar unit and does not need digestive enzymes to break it down, it cannot pass freely across the intestinal membrane for absorption; it needs to be transported. The body’s system for transporting fructose is limited and can get overwhelmed when a lot of Fructose has been eaten at once (8).
  • Polyols– Polyols are slowly absorbed and like fructose. If an excessive amount is eaten, not all polyols will be absorbed (3).

More FODMAPs in the diet = an increase in symptoms

high fodmaps and ibs symptomsConsistently eating a diet high in FODMAPs can have an effect like what is illustrated in this image.

A repeated cycle of:

  • High FODMAP diet
  • Unabsorbed FODMAPS in GI tract
  • Increased gas and water in the colon
  • Increased severity & frequency in IBS symptoms

The key to stopping symptoms is to stop this cycle.

High FODMAP Food list

Here is a list of common high FODMAP foods (3). These are the foods you will want to avoid if you decide to start a low FODMAP diet. Don’t worry, this doesn’t mean you will never be able to eat any of these foods ever again! We are investigating which individual foods trigger you, but we start with all of them.

  • FRUIT: Apples, Apricots, Blackberries, Cherries, Currants, Dates, Figs, Guava, Lychee, Mango, Nectarines, Peaches, Pears, Pineapple, Pomegranate, Plums, Prunes, Raisins, Watermelon
  • VEGETABLES: Artichokes, Asparagus, Baked Beans, Beetroot, Canned Re-fried Beans, Edamame, Garlic, Garlic Salt, Garlic Powder, Leeks, Mushrooms, Onions, Onion Salt, Onion Powder, Pumpkin, Shallot, Sweet Potatoes, Watercress
  • BREAD/CEREALS: Wheat products such as bread, crackers, pasta, cereals and pastries, Rye bread, Rye crackers, Sweetened breakfast cereals, Chickpea flour, Bean flour, Naan, Cous Cous
  • DAIRY/DAIRY ALTERNATIVES: Milk, Buttermilk, Cream Pasta sauce, Evaporated milk, Flavored milk, Custard, Mascarpone cheese, Ice cream, Soy milk, Yogurt
  • PROTEIN: Meat of Fish that is commercially breaded, Pistachios, Cashews
  • SWEETENERS: Agave syrup, Coconut sugar or nectar, Date sugar, Fructose, Fruit Juice Concentrate, High Fructose Corn Syrup, Honey, Mannitol, Maltitiol, Molasses, Palm sugar, Sorbitol, Sucralose, Xylitol
  • OTHER ITEMS: Hummus, Tahini paste, Milk chocolate, White chocolate, Cocoa powder, carob chocolate, Carob powder, Sugar free gum, mints and cough drops
  • DRINKS: All fruit juice, Soft drinks or sports drinks containing high fructose corn syrup, Sweetened milk, Soy milk

Low FODMAP food lists and recommended intake per day

Now that we have covered what not to eat let’s focus on what you can eat! Be sure to eat foods from all the different groups.

Fruit

It is recommended to eat 2 servings of fruit from the low FODMAP list per day. Avoid having more than 1 serving per meal and stick to a serving size of ½ cup.

Remember when a low FODMAP food is eaten in large amounts it can become high FODMAP!

LOW FODMAP FRUITS, SERVING SIZE= ½ CUP
banana, blueberries, cantaloupe, cranberries, grapefruit, grapes, honeydew melon, Kiwi, Lemon, Lime, oranges, papaya, pineapple, raspberries and strawberries

Vegetables

It is recommended to eat at least 3 servings of vegetables from the Low FODMAP list per day to help meet the recommended daily intake of fiber. Eat a variety of types and colors to get all the vitamins and minerals your body needs.

LOW FODMAP VEGETABLES, SERVING SIZE= ½ CUP
arugula, bamboo shoots, bean sprouts, bell peppers, bok choy, cabbage, carrots, chives, chili pepper, cucumbers, dill pickle, eggplants, green beans, kale, lettuce, olives, parsnips, radishes, rutabaga, spinach tomatoes, turnips, potatoes, water chestnuts and zucchini

Breads and Cereals

It is recommended to get at least 6 servings of grain products each day. Low FODMAP diet is not a gluten free diet, only foods that contain a high amount of wheat are restricted such as bread, cereal, crackers, pasta, most desserts. You may choose the gluten-free version of these items.

LOW FODMAP BREADS AND CEREALS
amaranth, gluten free breads, gluten free cereals, gluten free crackers, corn, cornmeal, corn or rice tortilla, grits, millet, oatmeal, oat bran, porridge, sorghum, tapioca and brown or white rice

Dairy/Dairy Alternatives

Aim for 3 servings of dairy or dairy alternatives each day. This food group is a good source of Vitamin D and Calcium which is essential for bone health in seniors.

LOW FODMAP DAIRY/DAIRY ALTERNATIVES, SERVING SIZE= 1 CUP MILK, 6-8 OZ OF YOGURT OR 1.5 OZ OF NATURAL CHEESE
lactose-free milk, Greek yogurt or lactose-free yogurt not containing high fructose corn syrup, cheese, unsweetened rice milk, oat milk, almond milk or hemp milk

Protein Foods

Include a protein rich food on the low FODMAP list with each meal and snack. It is import for seniors to get enough protein in their diet to prevent the loss of lean muscle mass and to support a healthy immune system.

LOW FODMAP PROTEIN FOODS
meat, beef, poultry, pork, fish that is fresh, not commercially breaded, fish that is tinned without sauce, eggs, flax seeds, poppy seeds, pumpkin seeds, sesame seeds, sunflower seeds, chia seed, firm tofu

Sweeteners

The low FODMAP diet is not a sugar-free diet, although, too much sugar should not be consumed for a healthy diet. Use the low FODMAP sweeteners in moderation.

LOW FODMAP SWEETENERS
aspartame, NutraSweet, equal, erythritol, glucose (dextrose) maltodextrin, saccharine, sweet-n-low, sugar twin and stevia

 

Implementing Low FODMAP

Now that you know which foods are high and low in FODMAPs, we are ready to get started implementing a low FODMAP diet. Remember, this process takes time and you are becoming an investigator. We are searching for your trigger foods.

phases of FODMAP diet

Phase One: elimination phase

This stage is very strict, and it is important to follow the diet as closely as you can to get maximum benefits. This phase removes high FODMAP foods from the diet and essentially “starves” the bacteria in your gut, allowing your gut to rest.

You should find some relief from IBS symptoms during the elimination phase (usually within 4-8 weeks). Once this has occurred phase two will begin. If symptoms do not improve within this time frame, consult your Doctor or Registered Dietitian. It is not safe to follow the elimination phase of the Low FODMAP diet for a long period of time (5).

Phase Two: reintroduction phase

Slowly reintroduce FODMAPS into the diet beginning with a food containing only one type of FODMAP (See list below for guidance). Start with a small amount of this food on Day 1 and gradually increase each day.

If symptoms do not worsen, this FODMAP may not be troublesome for you. If you experience a flare in IBS symptoms, do not proceed (you have found a trigger food!). Go back to following a low FODMAP diet again. Once your symptoms improve, you may start the process over. with a different FODMAP food (5).

Below is an example of how to reintroduce a FODMAP (5):

For reintroducing lactose, try skim or low-fat cow’s milk:

  • Day 1: 1/4 cup
  • Day 2: 1/2 cup
  • Day 3: 1 cup

The following are other FODMAPs to re-introduce with their suggested food (3):

  • Fructose: Honey or mango
  • Sorbitol: blackberries or avocado
  • Mannitol: cauliflower or sweet potato
  • Fructose + Sorbitol: Apples
  • Fructans- wheat: Bread
  • Fructans- fruit: Grapefruit
  • Fructans: Onion
  • Fructans: Garlic
  • Galacto-oligosaccharides: black beans, kidney beans, or almonds

Food and symptom diary

food diary for FODMAPsMake sure to keep track of the foods that are being reintroduced and any symptoms that occur after eating them.

The KEY is to figure out which foods can remain in your diet and which foods will need to be avoided long term.

This is a long process and it’s easy to forget what was done, so writing things down you go is so important!

Low FODMAP tips

Here are some general tips to make sure you do the low FODMAP diet the right way.

  • Balance out your meals-Aim to include a food from each food group at meals. Eat snacks in between meals if needed.
  • Eat Fiber-Fiber is important for a healthy diet, chose high fiber foods that are on the low FODMAP list such as oatmeal, brown rice, quinoa, pumpkin seeds or sunflower seeds. Don’t forget to eat 2 servings of low FODMAP fruit and 3 servings of low FODMAP veggies each day.
  • Drink Water- at least 8 cups a day to stay hydrated and avoid constipation. Stay away from excess caffeine and alcohol, these can dehydrate you and worsen IBS symptoms.
  • Gluten free ≠ FODMAP free Not all gluten-free foods pass as FODMAP free. Bean flour, chickpea flour or added inulin or chicory root can sometimes be found in gluten-free products. When in doubt, read the ingredients list- Watch out for ingredients likes onion salt or powder and garlic salt or powder, often these are found in store-bought soups or broths, flavored potato chips, salad dressings and store-bought pizza or pasta sauce.

low FODMAP breakfast

Low FODMAP Breakfast Ideas

Here are a few Low FODMAP breakfast ideas to get you started:

Low FODMAP Breakfast 1:

  • Oatmeal sweetened with cinnamon topped with sunflower or pumpkin seeds
  • ½ cup blueberries
  • Lactose-free milk
  • Hard-boiled egg

Low FODMAP Breakfast 2:

  • Breakfast Burrito: Spinach, tomato and egg scramble with cheddar cheese in a rice or corn tortilla
  • ½ cup of cantaloupe or kiwi
  • Lactose-free milk

Low FODMAP Breakfast 3:

  • Corn Chex or Rice Krispies with lactose free milk
  • 4 oz strawberry Greek yogurt
  • Turkey bacon

Or you can try a delicious low FODMAP smoothie in the breakfast- or any time of the day!

Low FODMAP Smoothie Recipe

INGREDIENTS:

  • ½ cup frozen raspberries or strawberries
  • ¼ cup fresh spinach
  • 1 tablespoon chia seeds
  • 4 oz lactose-free yogurt
  • ½ unsweetened almond milk

DIRECTIONS: Add all ingredients into a blender. Blend until smooth! So easy.

Potential risks of a Low FODMAP diet

Although low FODMAP diet is amazing in helping people relieve their IBS symptoms, it is important to know the potential risks and issues that may arise. It is a complicated diet and one best followed with the support of a dietitian or other FODMAP trained professional.

Not eating enough leading to unintentional weight loss

Simply taking high FODMAP foods out of the diet and not replacing these foods with other low FODMAP foods can lead to decreased nutrient intake and unintended weight loss. This can be a really big deal for older adults as it can lead to muscle loss and loss of independence.

Remember: a low FODMAP diet is not eating less, it is eating different. If you are finding it hard to maintain your weight, you may want to add more calorie dense foods like olive oil, seeds and nuts, cheese, full fat Greek or lactose-free yogurt and lactose-free whole milk.

Stress and anxiety surrounding eating

Restricting many foods from your diet can potentially cause increased stress around eating. As discussed earlier, stress can worsen symptoms!

Planning meals and snacks ahead of time can help put your mind at ease. Keep in mind this diet is not recommended for individuals with a history of or currently struggling with disordered eating.

Reduced prebiotic intake

Prebiotics act as food for the bacteria in your gut. Bacteria in the gut isn’t a bad thing. In fact, having a healthy balance of bacteria in your gut has been linked to improved immune function and mental health (11). Prebiotics are found in high fiber foods like fruits and vegetables. As we now know, many of these high fiber foods contain FODMAPs. By reducing FODMAPs in the diet, prebiotics are reduced as well.

During the elimination phase of a low FODMAP diet we are essentially starving the gut bacteria. This is good for relieving the IBS symptoms; although, reduced prebiotic intake for a long period of time may be a cause for concern. It is unknown what changing our gut bacteria long-term means for our overall long-term health.

We do know that fructans and galacto-oligosaccharides are prebiotics. Therefore, determining if you can tolerate them during phase two is important! If we can add them back that would be the best case senario. We would not want to restrict these foods in the diet unless it is necessary (meaning if these foods trigger your IBS) (6).

Low FODMAP success rate

The research and studies that have been done on low FODMAP diet show positive outcomes. One study showed 76% of people were satisfied with the results and reported less abdominal pain, bloating and flatulence. Another study showed 70% of participants reporting a decrease in IBS symptoms after only one week on a low FODMAP diet. (9,10)

Potential benefits of Low FODMAP diet

There are many benefits to following a Low FODMAP diet including:

  • Identify your trigger foods
  • Take control of bathroom habits
  • Enjoy food again!
  • Have more energy and a better quality of life

It’s a long and complicated process, but can have amazing benefits in the end. And there will be an end.

low fodmap diet older adults

Role of the Dietitian in a Low FODMAP Diet

Every individual is different when it comes to IBS triggers and symptoms. A registered dietitian can work with you to:

  • Ensure you are meeting all your nutritional needs during the strict elimination phase
  • Help you identify FODMAPs that are your biggest triggers during the reintroduction phase
  • Create a customized diet plan that you can follow long term

Conclusion

The low FODMAP diet is scientifically proven to help relieve IBS symptoms and to help with managing symptoms over time. If you or a loved one is suffering from chronic digestive issues that affect your everyday life, a low FODMAP diet may be right for you! Hopefully this article has given you a better understanding of how the low FODMAP diet works and how to follow it. Best of luck as you or your loved one work to improve IBS symptoms.

Low FODMAP Food List Infographic

High FODMAP Food List Infographic

References:

 

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  1. Alexis C. Prince, MRes, RD, Clio E. Myers, MRes, RD, Triona Joyce, PhD, RD, Peter Irving, MD, Miranda Lomer, PhD, RD, Kevin Whelan, PhD, RD, Fermentable Carbohydrate Restriction (Low FODMAP Diet) in Clinical Practice Improves Functional Gastrointestinal Symptoms in Patients with Inflammatory Bowel Disease, Inflammatory Bowel Diseases, Volume 22, Issue 5, 1 May 2016, Pages 1129–1136.
  1. J E Riby, T Fujisawa, N Kretchmer, Fructose absorption, The American Journal of Clinical Nutrition, Volume 58, Issue 5, November 1993, Pages 748S–753S, https://doi.org/10.1093/ajcn/58.5.748S [Accessed 4 Mar. 2020]
  1. Staudacher HM, Whelan K, Irving PM, Lomer MCE. Comparison of symptom response following advice for a diet low in fermentable carbohydrates (FODMAPs) versus standard dietary advice in patients with irritable bowel syndrome. Journal of human nutrition and dietetics: the official journal of the British Dietetic Association. https://www.ncbi.nlm.nih.gov/pubmed/21615553/. Published October 2011. [Accessed 10 Mar. 2020]
  1. Halmos, E., Power, V., Shepherd, S., Gibson, P. and Muir, J., 2020. A Diet Low In Fodmaps Reduces Symptoms Of Irritable Bowel Syndrome. [Accessed 10 Mar. 2020]
  1. Mayo Clinic. 2020. Prebiotics, Probiotics And Your Health. [online] Available at: <https://www.mayoclinic.org/prebiotics-probiotics-and-your-health/art-20390058> [Accessed 19 March 2020].

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