Understanding the Low FODMAP Diet: Foods, Phases and Tips for Managing IBS
Written by: Kelsey Moore, CDHF (BSc, RD), Andrea Senchuk (RD)
Updated: June 10th, 2026
What are FODMAPs?
The low FODMAP diet can improve bloating, abdominal pain, gas and altered bowel habits in roughly 3 out of 4 people. That success rate is incredibly appealing, so it’s not surprising that the diet is a hot topic these days.
Unfortunately, there is a lot of confusion among people with digestive disorders who are curious about the diet, so we’re on a mission to clarify a few things.
Today we’ll explore the low FODMAP diet, discover which foods contain FODMAPs, examine how FODMAPs affect the digestive system, and consider who may benefit from following the diet.
What is the Low FODMAP Diet?
The low FODMAP diet is a type of elimination diet that is used to improve digestive symptoms and identify foods that trigger those symptoms. It consists of 3 phases (stages):
- Elimination – In the elimination phase, which lasts roughly 2-6 weeks, a person eats only foods that are low in FODMAPs.
- Reintroduction – The reintroduction phase begins when digestive symptoms are under control. It involves a systematic process of testing the various FODMAP groups to see which ones trigger a person’s symptoms.
- Personalization – In the personalization phase, the person adds back into their diet foods from FODMAP groups that they tolerated well during the reintroduction phase, and limits foods from FODMAP groups that trigger symptoms.
A strict low FODMAP diet is not intended to be a permanent diet because not all FODMAPs trigger symptoms in all people. A person’s response to the types and amounts of FODMAPs is highly individual.
Therefore, a strict low FODMAP diet can impose unnecessary food restrictions that potentially reduce dietary variety. This, in turn, may negatively affect one’s microbiome and nutritional intake.
What Are FODMAPs?
FODMAPs are a group of carbohydrates found in everyday foods that are poorly absorbed in the small intestine. As they move through the digestive tract, FODMAPs draw water into the intestine and then undergo fermentation by gut bacteria in the large intestine. The fermentation of FODMAPs produces gas and other by-products.
It is estimated that up to 80% of people with irritable bowel syndrome (IBS) may benefit from a low FODMAPs diet. Those who benefit may experience improvement in overall symptoms, as well as reduction in abdominal pain, bloating, excessive gas and diarrhea (1, 2, 3).
What Does “FODMAP” Mean?
FODMAP is an acronym for Fermentable – Oligosaccharides – Disaccharides – Monosaccharides – And – Polyols. Each of these is explained below:
F- Fermentable
- Fermentable carbohydrates are sugars that bacteria in our large intestine break down, which causes the release of gas and other by-products.
O- Oligosaccharides
- Oligosaccharides are short chains of carbohydrate molecules linked together.
- There are two major groups of oligosaccharides: fructans and galacto-oligosaccharides (also called GOS).
- Fructans are found in fruits, vegetables, wheat and legumes but are found in particularly high amounts in garlic, and onion. Legumes and nuts typically contain GOS.
- These FODMAPs are highly fermentable and recent research indicates that IBS patients tend to be more sensitive to fructans on average compare to any other FODMAP group.
- These FODMAPs are highly fermentable.
D- Disaccharides
- Disaccharides are carbohydrates made up of two sugar molecules linked together.
- The disaccharide that is targeted by the low FODMAP diet is lactose, which is found in dairy and is made up of glucose and galactose.
- Lactose must be broken down by the digestive enzyme lactase before it can be absorbed in the small intestine. In people with lactose intolerance, the level of lactase enzyme is insufficient to properly digest lactose. As a result, lactose draws water into the intestine and travels to the colon, where it is fermented by bacteria, which may cause symptoms like diarrhea and bloating.
M- Monosaccharides
- Monosaccharides are carbohydrates made up of a single sugar molecule.
- Fructose, the sugar found in many fruits and some vegetables, is a monosaccharide that may trigger digestive symptoms in those with IBS that are sensitive to high amounts of this sugar.
- In foods containing equal amounts of fructose and glucose, glucose helps fructose be completely absorbed in the intestine. However, when fructose is present in greater quantities than glucose, the body doesn’t absorb fructose effectively.
A- And
P- Polyols
- Polyols, also called sugar alcohols, are a type of carbohydrate that humans can only partially digest and absorb in the small intestine.
- Polyols, such as sorbitol, mannitol, xylitol, maltitol and isomalt, mimic the sweetness of sugar.
- They are found naturally in fruits and vegetables, and are used as low-calorie sweeteners in sugar-free and diet products.
How Do FODMAPs Affect the Digestive System?
Although FODMAPs are not the cause of digestive disorders such as IBS, they can trigger gastrointestinal symptoms.
FODMAPs, especially fructose and polyols, draw water into the intestine, which propels intestinal contents forward quicker. Bacteria then ferment FODMAPs arriving in the large intestine and release gas. The gas and excess fluid distend (stretch) the intestine, which stimulates the many nerves that weave through the digestive tract.
In people with IBS, the nerves of the gut are unusually sensitive. Even a small change in the intestinal volume can cause the nerve network to overreact, and the brain interprets this as discomfort and pain.
Each person has an individual threshold for tolerating FODMAPs, with some people being sensitive to small amounts of FODMAPs and others being sensitive to larger amounts.
Additionally, each person is also unique with regards to which FODMAPs trigger symptoms. That being said, emerging research suggests that oligosaccharides (fructans and GOS) may be the most common triggers (4).
Which Foods Contain FODMAPs?
FODMAPs are found in foods that contain carbohydrates, such as fruits, vegetables, legumes, nuts, grains and flours, dairy, and sweetening agents.
Animal proteins, like beef, lamb, pork, poultry, eggs, fish and seafood do not contain FODMAPs, nor do fats such as oil, butter and ghee.
A diet lower in foods that contain moderate and high amounts of FODMAPs and manages the total FODMAP load at each meal may improve gastrointestinal symptoms.
Download the understanding FODMAPs PDF
The most comprehensive and up-to-date source of information on which foods contain FODMAPs is the Monash University FODMAP app. Monash University developed the low FODMAP diet, and their scientists regularly test the FODMAP content in a wide range of foods. FODMAP Friendly has another app that provides information on FODMAPs based on laboratory testing.
FODMAP content in foods can change over time; therefore, lists of foods may become outdated. It’s always wise to check the Monash app or FODMAP Friendly app for the most current food lists.
Table 1: High FODMAPs Foods
High FODMAP foods can be replaced with choices from the low FODMAP foods list (as seen in table 2) to help maintain a nutritious and well-balanced diet.
The Monash FODMAP app displays low FODMAP serving sizes for many of the high FODMAP foods listed below. This allows people to expand their food choices while on the low FODMAP diet.
Here is a list of generally high FODMAP foods that typically need to be temporarily eliminated during phase 1 of a low FODMAP diet. These foods are typically high FODMAP even in small serving sizes.
FRUCTANS
Vegetables
- artichokes
- beets
- brussels sprouts
- chicory root
- garlic
- hummus
- leek
- onions
- onion and garlic salt or powders
- pumpkin
- spring onions (white part)
Fruits
- apricots, dried
- banana, ripe
- cranberries, dried
- currants, dried
- figs, dried
- grapefruit
- honeydew melon
- nectarine
- persimmon
- pomegranate seeds
- prunes
- raisins
- watermelon
Grains
- barley
- couscous
- rye
- wheat
- fructooligosaccharides
- inulin
Sweeteners
- Corn syrup
GALACTO-OLIGOSACCHARIDES (GOS)
Legumes
- baked beans
- black beans
- bortolotti beans
- chickpeas
- green peas
- kidney beans
- legume flours
- lentils
- soybeans
- soy milk
- tofu, silken
Nuts
- cashews
- pistachios
LACTOSE
Milk Products
- milk (cow, goat or sheep)
- custard
- condensed and evaporated milk, dairy
- desserts
- ice cream
- powdered milk
- yogurt
Cheese
- soft and unripened (ricotta, cottage, cream, marscarpone)
EXCESS FRUCTOSE
Vegetables
- asparagus
- bell pepper – red, yellow, orange
- snap peas
Fruits
- apples
- cherries
- figs
- grapes
- mangoes
- pears
- watermelon
Sweeteners
- agave
- fructose-glucose
- honey
POLYOLS
Fruits
- apples
- apricots
- apricots, dried
- blackberries
- cherries
- lychees
- nectarines
- peaches
- pears
- plums
- prunes
- watermelon
Vegetables
- cauliflower
- celery
- corn
- mushrooms
- pumpkin
- snow peas
Sweeteners
- sorbitol
- mannitol
- isomalt
- maltitol
- xylitol
High FODMAP Beverages
Alcohol
- Port
- Rum
Tea
- Chai, strong
- Chamomile, strong
- Oolong, strong
Coffee
- Specialty espresso drinks with cow’s milk or soy milk
Juice
- Apple
- Orange
- Tomato
Other
- Cola, regular and diet
- Coconut water
Table 2: Low FODMAP Foods
Examine ingredients on gluten-free products such as breads, pastas and cereals, to ensure high FODMAP ingredients like honey, agave, legumes, glucose-fructose and inulin are not present.
Vegetables
- 2 cups arugula
- 2 cups bean sprouts
- 1/3 cup beets, canned
- ¼ medium green bell peppers
- 1 small or 1 cup bok choy
- ¾ cup broccoli, heads only
- ¾ cup red cabbage
- ¾ cup white cabbage
- 1 small carrot
- 1 cup collard greens
- ½ cup corn, canned
- ½ cup diced cucumber
- 1 cup eggplant
- 15 green beans
- ½ cup kale
- 1 cup leek, green parts
- 1 ½ cups lettuce, iceberg and romaine
- 7 okras
- 1 medium parsnip
- ¼ cup potatoes
- 4 radishes
- ¼ cup rutabaga
- 1/3 cup sauerkraut (red cabbage)
- 2 sheets seaweed, dried
- 1 ½ cup spinach
- ½ cup spaghetti squash
- 1 ½ cups swiss chard
- ½ cup tomato, canned
- ½ medium turnip
- 1/3 cup yam
- 1/3 cup sweet potatoes
Fruits
- 1 medium banana, firm
- 1 cup blueberries
- 4 tablespoons coconut, shredded, dried
- 4 medium cumquats
- 1 medium dragon fruit
- 1 medium guava
- 2 medium kiwis
- 1 medium mandarin orange
- 1 medium orange, navel
- 1 cup papaya
- 2 medium passionfruits
- 1 cup pineapple
- 1 cup rhubarb
Grains
- 2 slices bread, sourdough
- 2 slices bread, gluten-free
- ½ cup buckwheat groats
- 1 slice corn bread
- 2 small corn tortillas
- 2/3 cup flour – arrowroot, buckwheat, corn, millet, quinoa, rice, sorghum
- ½ cup millet
- ½ cup gluten free oats
- 124 g cooked pasta – gluten-free and made from low FODMAP flours
- 1 cup quinoa
- 1 cup rice – white and brown
- 4 cakes rice cakes
- ½ cup rice noodles
- 1/3 cup soba noodles (100% buckwheat)
Legumes
- 1/4 cup chickpeas, canned and rinsed
- 1/3 cup lentils, canned and rinsed
- 1cup firm tofu
- 1 cup tempeh
Nuts and Seeds
- 10 Brazil nuts
- 2 tablespoons chia seeds
- 3 tablespoons hemp hearts
- 32 peanuts
- 15 pecan halves
- 2 teaspoons pine nuts
- 3 tablespoons pumpkin seeds
- 15 macadamia nuts
- 3 tablespoons sesame seeds
- 15 walnut halves
Milk Products
- 1 cup almond milk
- ½ cup cream, whipped (35% milk fat)
- 2 slices hard cheese – cheddar, mozzarella, parmesan, swiss
- 1 cup lactose-free milk
- ¾ cup lactose-free yogurt
- 2 tablespoons lactose-free soft cheese (cottage, cream, ricotta)
- ¾ cup lactose-free ice cream
Sweeteners
- ¼ cup brown sugar
- ¼ cup cane sugar
- 1 teaspoon coconut sugar
- 2 tablespoons maple syrup
Low FODMAP Beverages
Alcohol (Note: alcohol in general can be a gut irritant for some individuals and it’s best to limit or avoid consumption)
- 1 375 ml can beer
- 1 oz brandy
- 1 oz gin
- 1 oz tequila
- 1 oz vodka
- 150 ml glass wine, white and sparkling
Tea
- 1 cup black, weak
- 1 cup green
- 1 cup peppermint
- 1 cup rooibos, weak
Coffee (Note: caffeine can be a gut irritant for some individuals)
- 1 cup coffee, drip
- 30 ml espresso
- 1 cup specialty espresso drinks with lactose-free milk or almond milk
Juice
- ¾ cup cranberry, 100%
- ¾ cup lemonade
Who May Benefit from the Low FODMAP Diet?
If you experience any of the symptoms commonly associated with IBS, consult your physician.
In addition to other treatments your doctor may recommend, the low FODMAP diet may be an effective strategy to ease the pain, gas, and altered bowel patterns commonly experienced in IBS.
Research indicates the low FODMAP diet is best implemented under the supervision of a qualified health care professional, such as a registered dietitian.
We encourage you to seek additional sources that are supported by recent scientific evidence.
FAQs
- Is the low FODMAP diet gluten-free?
Yes, in phase 1 of the low FODMAP diet it is a gluten-free diet. However, the temporary elimination of gluten does not mean you need to eliminate it long term. Only those with a diagnosed Celiac disease need to avoid all gluten.
Foods that contain gluten often contain fructans so some people notice a reduction in symptoms when eliminating gluten but this is often mistaken for a fructan intolerance not a gluten intolerance.
Your dietitian can help you determine if you have a possible gluten intolerance or fructan intolerance.
- Low FODMAP substitutions for onions and garlic?
Garlic or onion infused oils are great replacements for their whole counterparts. These oils do not cause IBS symptoms because fructans found in these foods are not soluble in oil, meaning they will not leech out of the oil and cause unwanted symptoms.
- Are there low FODMAP diet risk and nutritional deficiencies possible on this diet?
Potentially. If not followed carefully to ensure all nutrient needs are met it is possible to have nutritional deficiencies on this diet. Common nutrients of concern are: calcium, iron, zinc, magnesium and B vitamins.
Work with a registered dietitian to reduce the risk of deficiency.
Other Approaches to IBS Treatment
While the low FODMAP diet is well researched to treat a majority of IBS patients with symptom management, this diet is not the best approach for everyone.
Namely, children, those with cognitive impairment, or those with a history of disordered eating or diagnosed eating disorder are advised to follow a strict low FODMAP diet.
Further, those with a busy schedule, limited cooking time/skills may also benefit from other treatment methods.
Other treatment strategies include:
- IBS targeted supplements
- Medications for symptom management
Work with your medical doctor to determine which approach is best for you and your individual needs.
This guide is meant to explain the basics only, and CDHF encourages any IBS patients who are thinking about attempting this elimination diet for themselves to do so under the guidance of a registered dietitian. Use the contact form below to reach out to CDHF if you’d like to be connected with a dietitian in your area.
Want to learn more about low FODMAP? Check out these articles to learn more:
- Low FODMAP Diet: Dietitian Tips to getting more Fibre
- Low FODMAP Smoothie Options
- The Low FODMAP Diet for Children
- Low FODMAP Breakfast
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