Food allergy or intolerance?

Food allergy

• It involves the immune system, most often through IgE antibodies.
• Reactions usually appear quickly after eating, sometimes with very small amounts.
• They can affect the skin, digestion or breathing, and can be severe.
• Diagnosis is made by a doctor or allergist (clinical history, skin tests, blood tests, sometimes a supervised food challenge).

Food intolerance

• It is not an allergic reaction: it is often difficulty digesting or absorbing a component (e.g. lactose, fructose).
• Symptoms are mainly digestive: bloating, pain, changes in bowel habits.
• They often depend on the amount eaten: a small portion may be well tolerated.

Coeliac disease is a separate case: an autoimmune disease triggered by gluten, which must be tested for before gluten is stopped.

What is best avoided

• Cutting out foods without medical advice, based on a feeling or an unvalidated test.
• Stopping gluten before coeliac testing, which can distort the results.
• Piling up exclusions: the diet becomes poorer and the risk of deficiencies rises.

The dietitian's role

• Turning the doctor's diagnosis into practical meal guidance.
• Learning to read labels and spot hidden sources.
• Replacing avoided foods to keep a complete intake (calcium, fibre, protein).
• Supporting gradual reintroduction when medically possible.