1 Food aversion, unpleasant reactions caused by emotional responses to certain foods rather than to the foods themselves, which are unlikely to occur in blind testing when the foods are disguised.
2 Food allergy, physiological reactions to specific foods or ingredients due to an immunological response. Antibodies to the allergen are formed as a result of previous exposure or sensitization, and cause a variety of symptoms when the food is eaten, including gastro-intestinal disturbances, skin rashes, asthma, and, in severe cases, anaphylactic shock, which may be fatal.
3 Food intolerance, physiological reactions to specific foods or ingredients which are not due to immunological responses, but may result from the irritant action of spices, pharmacological actions of some naturally occurring compounds (e.g. caffeine), or an inability to metabolize a component of the food as a result of an enzyme defect.
See also amino acid disorders; disaccharide intolerance; genetic disease.