There is an individual's susceptibility to certain foodstuffs. These reactions are divided into immune-mediated and non immune-mediated reactions. The term food allergy is commonly used for immune-mediated reactions, while non immune-mediated reactions are reffered to as food intolerance. Food allergy can be further divided into IgE-mediated and non IgE-mediated reactions. Non immune-mediated food adverse reactions, or food intolerance, are definitions used when the history and/or the provocative tests clearly prove the causative role of a food but there is no evidence of an immunological mechanism. Adverse reactions to food are listed together with the possibilities how to decrease their unwanted effects.