What are Food Intolerances (Lactose, Fructose, FODMAP Sensitivity)?
Food intolerances involve difficulty digesting certain components of food, resulting in gastrointestinal discomfort rather than an immune reaction. Common examples include lactose intolerance, fructose malabsorption, and FODMAP sensitivity. FODMAP refers to Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols, a group of short-chain carbohydrates that are poorly absorbed in the small intestine. When these sugars are not properly digested, they can be fermented by gut bacteria, triggering bloating, pain, excess gas, and altered bowel habits. Unlike food allergies, intolerances are not life-threatening but can significantly impact quality of life.
What are the Causes of Food Intolerances?
Food intolerances arise from problems digesting or absorbing specific sugars and carbohydrates.
Lactose intolerance may result from:
- Reduced lactase enzyme levels
- Intestinal injury (coeliac disease, infection)
- Genetic predisposition
- Fructose intolerance/malabsorption may be caused by:
- Impaired fructose transport in the small bowel
- High fructose load in the diet
- Underlying bowel disorders
FODMAP sensitivity may be linked to:
- Poor digestion of short-chain carbohydrates
- Gut hypersensitivity
- Irritable bowel syndrome
What are the Symptoms of Food Intolerances?
Symptoms vary by person and food trigger, but may include:
- Abdominal bloating and distension
- Cramping or pain
- Diarrhoea, constipation, or alternating patterns
- Excess gas
- Nausea
- Urgency after meals
Symptoms often appear within hours of eating and improve with dietary modification.
How are Food Intolerances Diagnosed?
Diagnosis is based on medical history, dietary assessment, and symptom correlation. Tests may include breath tests for lactose and fructose, elimination diets, or structured FODMAP trials with professional supervision. Coeliac disease and inflammatory disorders may be excluded through blood tests or endoscopic evaluation.
What are the Treatment Options for Food Intolerances?
Management focuses on identifying triggers and adapting intake. Strategies may include reducing lactose, limiting high-fructose foods, or following a structured low-FODMAP diet. Digestive enzymes, probiotics, and nutrition support may help. Working with a dietitian ensures safe, balanced nutrition while minimising symptoms long term.