A low-FODMAP diet is designed to help people with irritable bowel syndrome (IBS) have better control over their symptoms by limiting certain foods. The diet involves three steps: restriction, reintroduction, and maintenance. It is not recommended that people try a low-FODMAP diet without a diagnosed gut condition.
Understanding FODMAPs
FODMAPs stands for fermentable oligo-saccharides, di-saccharides, mono-saccharides, and polyols. Put more simply, FODMAPs are certain types of carbohydrates -- the sugars, starches, and fiber in foods. For most, these foods are not a problem unless you eat too much of them. But some people are sensitive to them even in smaller amounts. This can worsen symptoms of IBS and other digestive conditions, such as bloating, diarrhea, cramping, and constipation.
These types of carbs are FODMAPs:
- Fructose: Fruits, honey, high-fructose corn syrup, agave
- Lactose: Dairy
- Fructans: Wheat, onions, garlic
- Galactans: Legumes such as beans, lentils, and soybeans
- Polyols: Sugar alcohols and fruits that have pits or seeds, such as apples, avocados, cherries, figs, peaches, or plums
Why are FODMAPs Difficult to Digest?
FODMAPs are fermentable short-chain carbohydrates. That means they are sugar molecules linked together in chains and can be fermented by bacteria in your gut. Molecules in chains need to be broken down into single molecules to be absorbed through your small intestine. But FODMAPs can’t be broken down, so they can’t be absorbed there. Your small intestine draws in extra water to help move the FODMAPs through to your large intestine. There, the bacteria living in your colon have a field day fermenting them (eating them). This produces gasses and fatty acids as byproducts inside your gut.
Are FODMAPs Bad for Everyone?
Not at all. In fact, our digestive systems are designed to process some foods that we can’t fully digest ourselves - for example, dietary fiber, which has an important place in digestive health. And feeding the bacteria in our gut is part of our symbiotic arrangement with those bacteria. But some people with sensitive guts experience a level of indigestion from these foods that significantly impacts their quality of life. For these people, the byproducts of fermentation cause chronic symptoms of gas, bloating, abdominal pain and distension. The extra water drawn by the small intestine may cause diarrhea in excess, or constipation if there isn’t enough.
Read also: Weight Loss with Low-FODMAP
Who Might Benefit from a Low-FODMAP Diet Plan?
The low-FODMAP diet is often prescribed for limited periods for people diagnosed with irritable bowel syndrome (IBS) and small intestinal bacterial overgrowth (SIBO). Studies show that a majority of people living with these conditions benefit from the diet. It can also be used as a short-term elimination diet for anyone who has digestive problems and wants to try and isolate the foods that are causing them. An elimination diet removes common problem foods and then adds them back in systematically to observe how your system reacts. The low-FODMAP diet is just one of many elimination diets that you can use to discover food sensitivities.
The Three Phases of the Low-FODMAP Diet
The low-FODMAP diet consists of three phases: elimination, reintroduction, and maintenance.
1. Elimination Phase
During the elimination phase, which lasts for two to six weeks, you’ll avoid all of the high-FODMAP foods. At first glance, the elimination phase of the diet may seem very limited. But there’s still a good list of foods in each category that you can eat. It takes some mental discipline to follow, but you won’t go hungry on the diet.
2. Reintroduction Phase
After two to six weeks, you’ll slowly reintroduce foods, one category at a time, to see which ones you can tolerate. The length of the reintroduction phase varies from person to person, but on average, it takes about eight weeks.
3. Maintenance Phase
In the maintenance phase, the goal is to figure out which foods trigger your digestive problems and create a long-term diet that gives you all the nutrients you need but includes only the FODMAPs you can handle. You may have different reactions to some FODMAP carbs than other people. The third phase keeps what works for you and leaves out what doesn’t.
Read also: Delicious low-FODMAP vegan recipes
Foods to Eat and Avoid on a Low-FODMAP Diet
You'll have many foods you can eat on this diet, but there's a steep learning curve about what items are high in FODMAPs and what you could choose instead. Certain fruits, vegetables, grains and proteins are higher and lower in FODMAPs. Some are OK to eat in limited amounts but will bother you in larger amounts.
Low-FODMAP Foods
Foods low in FODMAPs include:
- Vegetables: Bell peppers, carrots, cucumbers, spinach, kale, and other leafy greens, tomatoes, celery, bok choy, eggplant, green beans, pumpkin and winter squash, radishes, yams, zucchini
- Fruits: Most fruits are high in fructose, but these can be eaten in small amounts: Bananas, blueberries, raspberries, and strawberries, grapes, tangerines, cantaloupe, grapefruit, kiwi, lemons and limes, papaya, passion fruit
- Proteins: Plain cooked meats, including beef, chicken, lamb, pork, and turkey, plain fresh or frozen fish and seafood, firm tofu
- Dairy, dairy alternatives, and eggs: Almond, coconut, rice, and soy milks, lactose-free milk or yogurt, hard cheeses, eggs
- Nuts and seeds: Almond butter, macadamia nuts, peanuts, walnuts, seeds
- Grains and starches: Oats, potatoes, quinoa, rice
- Sweeteners: Dark chocolate, maple syrup, table sugar, aspartame
- Beverages: Coffee, diet soda, some teas (avoid chamomile, dandelion, fennel, and oolong)
High-FODMAP Foods to Avoid
Foods you should avoid, at least temporarily, include:
- Vegetables: Garlic, onions, artichoke, asparagus, leeks, mushrooms, sugar snap peas, broccoli, Brussels sprouts, cabbage, cauliflower, green and yellow beans, summer squash
- Fruits: Apples, applesauce, apple juice, mango, nectarines, peaches, pears, pineapples, bananas, apricots, avocados, dried fruit (raisins, currants, dates, figs, prunes), fruit juice, grapes, lychee, blackberries, canned fruit, cherries, plums, watermelon
- Beans and legumes: Beans, black-eyed peas, chickpeas, pinto beans, soy beans, split peas, lentils, lima beans, kidney beans, cannellini beans
- Meat, poultry, and seafood: Marinated meat, poultry, or seafood, sausages and salami, processed meats
- Dairy and dairy alternatives: Cow, goat, and sheep milk and all products made with them, coconut milk, soy milk, yogurt, custard, ice cream, soft, unripened cheeses and fresh cheeses like brie, cottage cheese, cream cheese, ricotta, sour cream
- Grains: Barley, rye, wheat
- Nuts: Cashews, pistachios
- Sweeteners: Agave, high-fructose corn syrup, honey, sugar substitutes, isomalt, lactitol, maltitol, mannitol, sorbitol, xylitol
Sample 14-Day Low-FODMAP Meal Plan
Here's a sample low-FODMAP meal plan to help you plan ahead:
Day 1
- Breakfast: Poached eggs on spelt sourdough with wilted spinach/kale
- Lunch: Quinoa, fried egg & sweet potato lunch bowl
- Dinner: Asian chicken salad
Day 2
- Breakfast: Porridge made with lactose-free milk, unripe banana, & cinnamon
- Lunch: Vegetable frittata
- Dinner: Vegan coconut curry
Day 3
- Breakfast: Spinach, feta, pine nut omelette
- Lunch: Tuna & sweet potato patties served with a green salad or steamed vegetables
- Dinner: Stir fried tofu and veggies with teriyaki sauce (carrots, broccoli, green beans) with rice noodles or rice
Day 4
- Breakfast: Cheese & tomato on toast
- Lunch: Carrot fritters served with poached eggs & rocket
- Dinner: Grilled salmon fillet with soy sauce, Asian greens (bok choy, choy sum) & brown rice
Day 5
- Breakfast: Oat and banana pancakes
- Lunch: Spelt sourdough sandwich with salad (rocket, sliced tomato, alfalfa, cucumber) + cheese
Day 10
- Breakfast: Smoothie bowl with lactose-free yogurt, strawberries (5 medium), kiwi, and a sprinkle of chia seeds. Served with gluten free bagel or English muffin.
- Lunch: Grilled chicken vermicelli bowl with shredded cucumber and carrots.
- Dinner: Pork tenderloin with mashed potatoes and sautéed spinach.
- Snacks: Hard-boiled eggs with carrots and cherry tomatoes (3).
Additional Meal and Snack Ideas
- Breakfast: Gluten free white toast + peanut butter (2 pieces), ¼ cup rolled oats + lactose free milk (cooked in microwave or stove), topped with ½ banana
- Lunch: Fresh Spring (Rice-Paper) Rolls (select a maximum of 3 veggies, and add a protein if you like), Quinoa Salad with Nuts
- Dinner: Chicken Nachos (omit taco seasoning, anything corn-based is gluten free, so that includes corn chips and corn tortillas)
- Snacks: 1 cup of carrot and cucumber sticks + 2-3 tbsp cottage cheese, Rice cakes with peanut butter, lactose-free yogurt, popcorn, hard boiled eggs or a handful of peanuts or walnuts
After following the entire plan for 14 days, simply choose your favorite recipes to have for the following 14 days. At this point, if you have noticed a significant improvement in your symptoms, it is time to start what is known as the Reintroduction Phase of a low FODMAP diet.
Read also: Delicious Low FODMAP Chicken
Tips for Low-FODMAP Meal Planning
Following an elimination diet like the low FODMAP diet takes some extra planning.
- Don’t think that you have to change your diet entirely. Instead, think about the meals that you would usually like to eat (e.g. spaghetti bolognaise or Thai green curry) and how it could best be adapted by swapping out foods that trigger your IBS with low FODMAP alternatives. Gluten-free alternatives and garlic-infused olive oils are great swaps for those fearful of losing wheat and garlic-based products!
- Educate yourself on label reading and how to spot FODMAPs in packaged foods so that you feel confident while shopping during step 1 of the FODMAP diet
- Spend some time on the weekend writing out what meals you want for the week (either on paper, in your phone notes, or even a whiteboard), from there you can write your FODMAP grocery list.
- Preparing some healthy low FODMAP meals in advance (Sundays are usually a good day for this) is also a great way to keep organized and avoid the stress of cooking or thinking of ideas throughout the week. So many delicious meals are easily frozen and are a real time-saver later on.
- Batch cooking: To reduce time spent in the kitchen, consider batch cooking a few times per week. Cook three or four servings of a recipe at once and eat the leftovers during the week. If you don’t eat the leftovers during the week, freeze them to last longer. Batch cooking can also help prepare lunches.
- Portion your food ahead of time: Portion your lunches into individual containers at the beginning of the week so they’re ready to load into your lunch bag.
- Consider buying pre-cut or frozen vegetables and fruits. Frozen produce is just as nutritious as fresh produce. Prepping fruits and vegetables can take time.
- Get creative with herbs and spices. Since onion and garlic are off-limits on the low FODMAP diet, experiment with different ways to enhance the flavor of your meals.
Low FODMAP Grocery Staples
- Grains: rice, rice noodles, gluten-free pasta, spelt sourdough/gluten-free bread, quinoa, oats
- Dairy/alternatives: lactose-free yogurt or milk if required, soy milk made from soy protein, almond milk fortified with calcium, firm cheeses
- Proteins: meat, chicken or fish that is not marinated or crumbed, eggs, firm tofu, canned legumes, seeds, walnuts, brazil nuts
- Vegetables: Aubergine/eggplant, green beans, bok choy, broccoli, carrot, cucumber, lettuce, potato, tomato, zucchini
- Fruits: Cantaloupe, kiwi fruit (green), mandarin, orange, pineapple, firm bananas, blueberries, raspberries
- Oils/fats: olive oil, garlic infused olive oil, butter
- Condiments/sauces: mustard, peanut butter, soy sauce, tahini, tomato sauce, vinegars, Worcestershire sauce, miso paste
Important Considerations and Potential Drawbacks
- The low-FODMAP diet can feel restrictive. It can be helpful to plan in advance and create a balanced meal plan that satisfies your taste buds and nourishes your body.
- Stress can exacerbate symptoms in individuals with IBS. If meal planning is something that causes you stress, try to spend some time on the weekend finding meals you might like during the week.
- If you eat some higher FODMAP meals by accident, don’t let it get you down! It won’t undo all of your hard work and is part of the learning process.
- Strict low-FODMAP diets may also lower levels of other helpful bacteria that produce butyrate, a substance that protects the gut lining while increasing the bacteria that damage it.
- Note: The low-FODMAP diet is unsuitable for individuals without IBS and may worsen food fears in people with eating disorders. It should also be avoided by people with restricted diets, such as vegans or those with food allergies, due to potential nutritional deficiencies. In addition, those with gastrointestinal issues have a higher prevalence of disordered eating.
- A low-FODMAP diet should be followed under the guidance of a dietitian who has specialty skills in managing IBS and using a FODMAP diet.
- You should also remember that a low-FODMAP diet isn’t designed to be a long-term or lifestyle diet. It should be used for managing the symptoms and identifying trigger foods while you’re treating the underlying causes.
- If you find the low-FODMAP diet too hard, you don’t need to cut out entire food groups. Simply try to eat less of the foods that bother you the most, such as garlic, onions, beans, apples, milk, mushrooms, and wheat.
- If your symptoms improved after 2-6 weeks on the Step 1 diet, it is time to move onto the Step 2 diet. If they did not improve, it might be that your IBS symptoms are not sensitive to FODMAPs and you need to consider other therapies, such as stress reduction, gut directed hypnotherapy, over-the-counter medications such as laxatives, fiber supplements, or prescription medications.
- Following a strict low FODMAP diet long-term is not recommended because it’s very restrictive. If you need help reintroducing foods to your diet after you’ve completed the elimination phase of the low FODMAP diet, a dietitian trained in gut health can help.