The FODMAP diet consists of removing foods that arefermentable oligosaccharides, disaccharides, monosaccharides and polyols from your diet. Examples include fruits like apples, pears and mangoes, dairy products, white wheat and beans.

These types of foods are poorly absorbed by the intestine, and trigger intestinal bacteria to ferment for longer periods. This can lead to symptoms such as indigestion, abdominal pain, excess gas, and diarrhea that can alternate with constipation.

Foods rich in FODMAP are normally excluded from diets to manage and prevent the symptoms of irritable bowel syndrome, a chronic inflammation in the intestine that can be caused by stress or poor diet.

How to start the FODMAP diet

To start the FODMAP diet you should remove all foods that are included in the list below for a period of 6 to 8 weeks, and monitor for any improvement in symptoms. If there is no improvement, the diet can be stopped after eight weeks and a new treatment should be started.

If the symptoms do improve, after eight weeks you should gradually reintroduce each food again, starting with one group at a time. For instance, you can start by introducing fruits first, such as apples, pears or watermelon, and see if the intestinal symptoms return.

This slow reintroduction of foods is important in order to identify foods that can worsen bowel symptoms, and that should be avoided or consumed in very small quantities.

Precautions

The FODMAP diet can lead to a low intake of important nutrients, such as fibers, carbohydrates or calcium. Thus, it's important for a doctor and a registered dietitian to supervise the diet to ensure the person remains in good health.

In addition, it's important to remember that this diet is effective for about 70% of patients with IBS. For those that do not benefit from this diet, a different treatment approach should be considered.

FODMAP foods to avoid

FODMAP foods that should be avoided can be classified into five different groups:

FODMAP Type	Natural Foods	Processed foods
Monosaccharides (fructose)	Fruits: apple, pear, peach, mango, green beans and beans, watermelon, preserves, dried fruits, fruit juices, and cherries.	Sweeteners: corn syrup, honey, agave nectar, and fructose syrup, which may be present in some foods, such as cookies, sodas, pasteurized juices, etc.
Disaccharides (lactose)	Cow's milk, goat's milk, sheep's milk, cream, ricotta, and cottage cheese.	Cream cheese, ice cream, yogurt, and other foods that contain milk.
Fructooligosaccharides	Fruits: persimmon, peach, apple, lychees, and watermelon. Legumes: artichokes, asparagus, beetroot, brussel sprouts, broccoli, cabbage, anise, garlic, onion, peas, abelmosk, shallot, red chicory. Cereals: wheat and barley (in big quantities) and couscous.	Foods with wheat flour, pastas with wheat, cakes, cookies, ketchup, mayonnaise, mustard, processed meats such as sausages, nuggets, prosciutto, and mortadella.
Galactooligosaccharides (GOS)	Lentils, chickpeas, tinned chickpeas, beans, peas, soy whole grains.	Products that contain these foods
Polyols	Fruits: apple, apricots, peach, nectarine, suckling pig, pear, plum, watermelon, avocado, and cherry. Vegetables: cabbage, mushrooms, and peas.	Sweeteners: xylitol, mannitol, maltitol, sorbitol, products with glycerine, erythritol, lactitol and isomalt

It is also very important to pay attention to the list of ingredients on processed food labels, since they may contain some of these foods.

What you can eat

The foods that can be included in this diet are:

Fruits, like tangerines, oranges, grapes, pineapples, passion fruit, starfruit, kiwis, strawberries, blueberries, papayas, lemons, bananas or melon;
Vegetables, like pumpkins, celery, chives, eggplant, olives, red peppers, tomatoes, spinach, zucchini, lettuce, carrots or cucumbers;
Lactose-free dairy products, like lactose-free milk, lactose-free yogurt, lactose-free cheeses, or ripened cheeses such as parmesan, brie or camembert cheeses;
Proteins like meat, tofu, fish, eggs or chicken;
Seeds, like chia seeds, flaxseed, sesame seeds, pumpkin seeds or sunflower seeds;
Nuts, likepeanuts, pine nuts, macadamia nuts, walnuts or Brazil nuts;
Tubers, such as cassava, potatoes, sweet potatoes, yams or tapioca;
Plant-based milks, such as coconut milk, oat milk or almond milk.

Your dietitian may also consider the use of probiotics as a complement to regulate the bowels, as it's proven that people who suffer from irritable bowel syndrome sometimes have an imbalance in gut bacteria. Some studies show that probiotics can help to directly relieve symptoms.

FODMAP diet meal plan

The following table gives an example of a three-day meal plan for a FODMAP diet:

Meal	Day 1	Day 2	Day 3
Breakfast	Banana smoothie: 200 ml of chestnut milk + 1 banana + 2 tablespoons of oats	Grape juice + 2 slices of bread without gluten with mozzarella cheese and egg	200 lactose-free milk + 1 tapioca with egg
Morning Snack	2 watermelon slices + 7 cashews	yogurt without lactose + 2 teaspoons of chia seeds	1 mashed banana with a tablespoon of peanut butter
Lunch/Dinner	Chicken risotto and vegetables: tomato, spinach, zucchini, carrot, and eggplant	Rice pasta with minced duck and tomato sauce with olives + lettuce, carrot, and cucumber salad	Boiled fish with vegetables: potato, carrot, leek and cabbage
Afternoon Snack	Pineapple juice + banana and oat cake	1 kiwi + 6 gluten-free oat cookies + 10 chestnuts	Strawberry smoothie with lactose-free milk + 1 slice of gluten-free bread with cheese

It's important to remember that you must monitor for foods that trigger bowel symptoms. This diet needs to be followed for six to eight weeks, under the supervision of a doctor or nutritionist.

The quantities included in the above plan may vary according to age, gender, physical activity and associated health conditions. Ideally, you should visit a registered dietitian for a thorough assessment in order to develop a more individualized meal plan according to your needs.