In food allergy, an abnormal immune system response results in the body making antibodies to 'fight off' a food. Food allergy, either IgE antibody mediated or delayed non-IgE mediated allergy are reactions caused by the immune system, which affects approximately 1% of adults and 5-9% of children in the UK.

 

However, some people suffer symptoms after eating certain foods even when they are not producing antibodies against them. A variety of different mechanisms can cause foods to affect people in this way. These non-immune reactions are known as food intolerances.