Exposing a patient to a substance to which the patient is thought to react adversely. Ethically, the test cannot be performed without the patient’s permission, but for accuracy the test foods should be disguised during the test. Typically, food challenges are performed after the patient has eliminated the suspected food from his or her diet for 1 or 2 weeks. To eliminate bias, the patient should agree to ingest several disguised foods that he or she is known to tolerate, in addition to the suspected food.
A food challenge involves the systematic re-inclusion of a suspected food into the diet, which was previously believed to cause adverse symptoms. Typically, this method is applied after an individual has been adhering to an elimination diet.