Low FODMAP Diet

What is the Low FODMAP Diet?

The Low FODMAP Diet is a specialised eating plan designed to help individuals manage symptoms of irritable bowel syndrome (IBS) and other digestive conditions. This diet works by reducing certain types of carbohydrates that can trigger bloating, gas, stomach pain, and changes in bowel movements.


What Are FODMAPs?

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. These are types of carbohydrates (sugars) that are poorly absorbed in the small intestine. When not properly digested, they travel to the large intestine, where bacteria ferment them. This fermentation can cause uncomfortable symptoms in some people.

Here’s what each part of FODMAP means:

  • Oligosaccharides: Found in foods like wheat, rye, onions, and garlic.
  • Disaccharides: Mainly lactose, found in milk, yogurt, and soft cheeses.
  • Monosaccharides: Fructose and glucose, found in apples, honey, and high-fructose corn syrup.
  • Polyols: Found in some fruits and vegetables, and in artificial sweeteners like sorbitol and mannitol.


Who Should Consider a Low FODMAP Diet?

This diet is commonly recommended for people with:

  • Irritable Bowel Syndrome (IBS)
  • Functional gastrointestinal disorders (FGIDs)
  • Chronic bloating and gas
  • Diarrhoea, constipation, or alternating bowel habits

It is not a weight loss diet or a general healthy eating plan. It is a targeted medical diet designed to reduce symptoms in people with sensitive digestive systems.


How Does the Low FODMAP Diet Work?

The Low FODMAP Diet is usually done in three phases:

1. Elimination Phase

This phase usually lasts 2–6 weeks. You remove all high FODMAP foods from your diet. This helps reduce your symptoms and identify whether FODMAPs are the cause.


2. Reintroduction Phase

You slowly reintroduce one FODMAP group at a time (for example, testing fructose one week and lactose the next). This helps identify which specific FODMAPs trigger your symptoms and how much you can tolerate.


3. Maintenance Phase

Once you know which FODMAPs affect you, you create a long-term eating plan that avoids only the FODMAPs you react to, while including the rest. This helps you eat a more varied and balanced diet.


What Foods Are High and Low in FODMAPs?

High FODMAP Foods to Avoid (During Elimination Phase)

  • Fruits: Apples, pears, watermelon, mangoes, cherries
  • Vegetables: Onions, garlic, cauliflower, mushrooms, asparagus
  • Grains: Wheat, rye, and barley 
  • Dairy: Milk, ice cream, yogurt, soft cheeses ( lactose)
  • Legumes: Lentils, chickpeas, kidney beans
  • Sweeteners: Sorbitol, mannitol, xylitol, maltitol


Low FODMAP Alternatives You Can Eat

  • Fruits: Bananas, blueberries, strawberries, oranges, kiwifruit
  • Vegetables: Carrots, spinach, zucchini, potatoes, eggplant
  • Grains: Oats, rice, quinoa, corn, gluten-free bread
  • Dairy: Lactose-free milk, hard cheeses (cheddar, parmesan), plant-based milks
  • Proteins: Eggs, meat, chicken, fish (not processed with high FODMAP ingredients)
  • Nuts and Seeds: Almonds, peanuts, pumpkin seeds


Benefits of the Low FODMAP Diet

  • Relief from digestive discomfort: Many individuals experience a significant reduction in symptoms like bloating, gas, abdominal pain, and irregular bowel habits.
  • Enhanced quality of life: With fewer digestive disruptions, people often report increased energy, confidence, and overall comfort in daily life.
  • Tailored nutrition: The reintroduction phase helps identify individual food triggers, resulting in a diet customised to your unique gut profile.
  • Healthy and balanced eating: With proper guidance, the low FODMAP diet can still offer a wide variety of nutritious foods that support long-term well-being.


Potential Downsides of the Low FODMAP Diet

  • Nutrient gaps: Restricting too many foods can reduce intake of fibre, calcium, and other key nutrients if the diet isn’t carefully balanced.
  • Prolonged restriction: Staying in the elimination phase too long may compromise gut health by limiting beneficial gut bacteria.
  • Social limitations: Dining out or travelling can become tricky due to limited food options and unclear ingredients.
  • Emotional and mental strain: Managing the phases of the diet without proper guidance can lead to stress, confusion, or frustration.
  • Disordered eating risks: The restrictive nature of the diet may trigger unhealthy eating habits or food anxiety in some individuals.
  • Financial cost: Low FODMAP alternatives can be pricey and harder to find, depending on where you live.
  • Diagnostic delays: Starting the diet without medical advice might mask symptoms of conditions like coeliac disease or IBD.


How Long Should You Stay on the Low FODMAP Diet?

The elimination phase should only be followed for a few weeks. Staying on a strict low FODMAP diet in the long term can reduce the diversity of beneficial bacteria in your gut. The goal is to identify triggers and develop a sustainable, flexible diet tailored to your needs.


What Happens if the Low FODMAP Diet Doesn’t Work?

If symptoms don’t improve after 4–6 weeks on the elimination phase, then:

  • It’s possible that FODMAPs are not your main issue.
  • Other conditions, such as coeliac disease, inflammatory bowel disease, or food allergies, may also be present.
  • It may be worth reviewing your food intake and symptoms with a healthcare professional to rule out other causes or potential errors in the process.


Tips for Success on the Low FODMAP Diet

  • Work with a dietitian: This helps ensure you're doing it correctly and safely.
  • Read food labels: Many packaged foods contain hidden FODMAPs like onion powder or high-fructose corn syrup.
  • Keep a food and symptom diary: This helps track what you eat and how you feel to spot patterns.
  • Be patient with the reintroduction phase: It takes time, but it is essential to personalise the diet.


Is the Low FODMAP Diet a Cure?

No, it is not a cure. The Low FODMAP Diet is a symptom management tool. IBS and other gut disorders are chronic conditions, but the diet helps reduce flare-ups and improve day-to-day comfort. The ultimate goal is to give you more control over your symptoms while allowing you to enjoy a wide range of foods.