An estimated one-third or half of the population believe that they have food intolerance. However, studies have indicated that such intolerance is less common. Health care professionals as well as patients mix up food intolerance and food allergy and mistake one for the other. The symptoms of food intolerance vary in time and involve many organs; the pathomechanism of food intolerance is often unknown. Therefore, diagnosing or exclusion of food intolerance may be quite difficult and challenging. Poor diagnostic feasibility leads to an inadequate and inappropriate restricted diet which can cause malnutrition, particularly in children.
The overview is focused on aetiology, reaction type (enzymes, pharmacological, non-specific) and diagnostic tools.