Frequently Asked Questions


Will I be on the low FODMAP diet forever?

No. In fact, the goal is for you to not to be on the diet forever.

  1. You'll eliminate all FODMAPs only until you feel better (about 2 to 4 weeks).
  2. Then, you'll slowly test each FODMAP group to figure out which groups are your triggers (about 6 to 8 weeks).
  3. After that, you'll know which FODMAPs to avoid or limit (these are your triggers), and which are well tolerated. Because everyone is a little different, the goal is to find your low FODMAP diet.

How soon will I start to feel better

Most people feel better in 2 to 4 weeks, but some take as little as a few days.

Don't we sound like repair guys? "We'll be there to fix your plumbing sometime between Friday and next month." But food is complicated, and one answer does not fit all.

If you don’t feel better, and that can happen, about half the people who try a low FODMAP diet do not feel better, consider working with a doctor or dietitian to make sure you’re following the diet properly. Or, you might look into medications to help your symptoms.

When I eat a challenge food, how long does it take for me to feel symptoms?

The short answer is: less than 1 day, up to 3 days.

The long answer is: it depends on two things…

  1. Transit time. Food moves through each of us at slightly different rates (that's called transit time). For some people, the food they eat today moves all the way through within 24 hours. For other people, it can be up to 3 days or even longer.
  2. Where symptoms happen.
    • If symptoms are in the stomach, they'll appear sooner (minutes to hours).
    • If symptoms are in the small intestine, they usually occur within 6 hours.
    • If symptoms are in the large intestine, they'll appear later (several hours to even days).

Who the diet is for

Does the FODMAP diet help everybody?

No. It only helps:

  • People who are sensitive to FODMAPs. These people most often have problems with bloating, lots of loud belly noises, excess gas, belly pain or cramping, or diarrhea.
  • People with certain GI disorders and diseases, like IBS (irritable bowel syndrome), IBD (inflammatory bowel disease) who are not in a flare but still have symptoms, and SIBO (small intestinal bacterial overgrowth) after antibiotic treatment.

Do all FODMAPs cause the same symptoms?

No. Different types of FODMAPs act differently in the body and cause different symptoms. Visit the Symptoms page to learn about each FODMAP group.


Is the low FODMAP diet expensive?

It can be. It depends on how you shop and eat.

Let's take wheat as an example. Wheat-free or gluten-free bread is more expensive than regular bread. If you really want to eat bread, buying special bread will cost more.

On the other hand, if you choose something different for your grain while you're on the diet (like brown rice, oatmeal, corn tortillas, or potatoes), there might be no change in the cost to you.

Will I have to shop at a specialty grocery store to eat a low FODMAP diet?

No. A lot of the low FODMAP foods (fruits, vegetables, rice, potato, meats, eggs) are typical items in most grocery stores. Most major grocery stores also carry lactose-free milk, sourdough or gluten-free bread, and gluten-free pasta (check in the gluten free section or in the freezer aisle for the bread).

Can I still have…

Can I still eat fruits and vegetables?

Please do! The idea is not to have you exclude all fruits and vegetables – just ones that are more likely to cause symptoms because they contain FODMAPs. There are a lot of fruits and vegetables that people on the low FODMAP diet can still enjoy.

Follow the Low FODMAP Food List to see which fruits and vegetables are safe to eat.

Can I drink alcohol?

In moderation, vodka, gin, whiskey, wine, and beer are OK for most people. But no more than 1 serving per day for women and 2 servings per day for men. Rum is the only liquor high in FODMAPs (it has fructose). Be careful of mixers that might have high fructose corn syrup, like regular soda.

One serving means:

  • Liquor: one 1.5-ounce shot
  • Wine: one 5-ounce glass
  • Beer: one 12-ounce can or bottle

Can I eat regular table sugar (sucrose)?

Yes, in moderation. Sucrose is actually made up of glucose and fructose. Most people can tolerate fructose when equal amounts of glucose are eaten at the same time. But if you have too much sucrose, you'll be eating more fructose, too, and some people may get symptoms if they eat too much.

A safe rule of thumb to keep sugar intake in check is to limit desserts that are high in sugar to one serving at a time. For example, according to a food label, one serving of vanilla lactose-free ice cream is ½ cup. This would be an appropriate amount of this food to eat when following the low FODMAP diet. Larger amounts may trigger symptoms.

Can I have artificial sweetener?

Some types. View the Low FODMAP Food List to see sweeteners that are low in FODMAPs.

Onion and garlic are added to a lot of packaged foods and seasonings. How strictly do I need to avoid these?

It’s important to check labels for onion and garlic. For the best results, try your best to completely avoid these foods during the elimination phase. Even the powdered forms should be avoided.

Can I still dine out in the elimination phase?

Yes. Here are a few tips:

  • Look up the menu ahead of time.
  • Avoid the obvious offenders like pasta dishes and bread.
  • Skip meals with sauces or soups (they will almost always contain onion and garlic).
  • Safe bets may include:
    • Grilled salmon with lemon (ask for no seasoning other than salt and pepper), steamed vegetables, and a baked potato with butter
    • Entrée salads with vinegar and oil or lemon juice as a simple dressing
    • Sushi (but avoid teriyaki sauce, spicy mayo, miso soup, and edamame)

Being healthy during the elimination phase

Is this a healthier diet than my regular diet?

It depends on the choices you make. If each meal includes a lean protein, a whole grain, healthy fat, and a fruit or vegetable from the low FODMAP list, it can be very healthy.

Do I need to take supplements if I'm on the low FODMAP diet?

No. If each meal includes a lean protein, a whole grain, and a fruit or vegetable from the low FODMAP list, you most likely will not need a supplement. In fact, some supplements contain FODMAPs, so be sure to check for additives.

It's best to talk to your doctor or dietitian to be sure.

Can I still eat a balanced diet?

Please do!

The low FODMAP diet doesn't entirely cut out any food groups. There are still some fruits, vegetables, proteins, beans, nuts, and grains you can eat. Making careful choices within each of these categories means you can still eat a balanced diet.

Will I lose weight on the diet?

Not necessarily. It depends on:

  • The choices you make. Making healthy choices about low FODMAP foods and portion size could mean you lose or maintain your current weight. On the other hand, there are low FODMAP foods that are unhealthy and could cause you to gain weight. Just like with any food, some low FODMAP foods are healthier than others, and the choices you make could affect your weight.
  • How you feel. When symptoms are at their worst, some people feel pretty awful, don't eat much, and may lose weight. After eliminating FODMAPs, some people feel a whole lot better and get their appetites back. In this case, following a low FODMAP diet may actually cause (or help) weight gain, simply because it’s possible to eat more when feeling better.

What are some low FODMAP sources of fiber?

Here are a few suggestions:

  • whole grains (like oatmeal, brown rice, quinoa)
  • baked potato with the skin
  • low FODMAP fruits, vegetables, nuts, and nut butters
  • adding chia seeds or hemp seeds to your lactose free yogurt
  • adding ground flax seeds to your oatmeal or low FODMAP rice cereal
  • adding chopped walnuts, almonds, or sunflower seeds to your salad

Where do I get my protein on the low FODMAP diet if I don’t eat meat and can’t eat beans?

While most beans and lentils are restricted on the low FODMAP diet, small amounts of canned, rinsed, and drained chickpeas and lentils can be used. Other good sources of plant-based protein include firm tofu, seitan, tempeh, quinoa, nuts, seeds, and seed butters. If additional protein is needed, you may also try mixing a brown rice protein powder into your oatmeal, cereal, smoothie, almond milk, or help milk.

It's not just dairy-free, gluten-free, or low carb

Is the low FODMAP diet dairy-free?

No, but it is lactose-free. Lactose is a sugar found in some dairy products, but not all dairy products are high in lactose. For example, hard and aged cheeses are very low in lactose because of the way they are made, so it's ok to eat them in small amounts.

Visit the Low FODMAP Food List to see which dairy products you can still eat. (Spoiler alert: there are quite a few!)

Is the low FODMAP diet gluten-free?

No. Low FODMAP is not the same as gluten-free. FODMAPs are carbohydrates and gluten is a protein. Watch this video to better understand how wheat can cause gut symptoms.

There is overlap between the two diets because FODMAPs and gluten are found in the same foods: wheat, rye, and barley. A gluten-free diet eliminates some FODMAPs (wheat, barley, and rye), but not all gluten-free items are okay for the low FODMAP diet. Say you buy a gluten-free bread. This loaf of bread could be sweetened with honey or agave, or it could have added chicory root to increase its fiber content. These ingredients are FODMAPs and should be avoided.

The point is: you will need to read the ingredients of gluten-free products to make sure there are not other FODMAPs in them.

Is the low FODMAP diet a low carb diet?

No, the low FODMAP diet only limits the carbohydrates (carbs) that are poorly absorbed and cause symptoms.

Challenge phase

If I don’t like a food, should I still challenge it?

Basically, yes… but we have two slightly different answers:

  1. First, let's say you don't like mango. That's easy. During your fructose challenge week, just choose a different food that has only fructose in it, like 1 teaspoon of honey or agave.
  2. Second (this one's harder), during the fructans challenges, we recommend two separate challenges for onion and garlic. Even if you don't like garlic, we'd recommend you challenge it anyway.

Here's why: garlic and onion are hidden in a lot of foods, especially in the ingredient "natural flavors." If you choose not to challenge garlic, you won't know how careful to be when reading food labels down the road.

Think of it this way (for foods you don't like): you're not challenging to see if you can eat it… you're challenging to see if you should actively avoid it.

I feel great and don’t want to bring back my symptoms. Do I still have to do all of the challenges?

Yes. The FODMAP diet is not meant to be a forever diet. The goal is to identify your trigger foods and increase the variety in your diet. We recommend starting with a small portion of your challenge food on the first day to test your tolerance. If you feel okay and don’t have symptoms, then increase the portion size for day 2 and day 3. If your symptoms return at any time during the challenge phase, remember that they are temporary and will go away by removing the challenge food. Remember, there is no benefit to avoiding foods that don’t bother you.