Allergy versus intolerance
A true food allergy triggers IgE antibodies. The symptoms are fast and obvious: swollen lips, rash, breathlessness, vomiting. Intolerance instead gives bloating, fatigue after eating, or a headache hours later. Its cause is often not immune at all, but a missing enzyme such as lactase, or sensitivity to compounds such as FODMAPs.
An honest note on IgG panels
Food IgG panels are popular although the evidence is weak. IgG antibodies to a food can simply mean you have eaten it, not that you react to it. So we use IgG results as one pointer for structuring an elimination trial rather than as a permanent banned list. Anyone selling you forty forbidden foods on IgG alone is overpromising.
Structured elimination
For most intolerance cases, structured elimination is still the most reliable method. We remove the suspected foods for three to four weeks, then reintroduce them one at a time while recording symptoms. We build that schedule with you, so your nutrition stays adequate throughout. Read the gut health pathway and the guide to gut problems.