A food allergy is a response from your immune system. Your body recognizes the food as a threat, which causes an inflammatory response which creates symptoms that can range from an itchy mouth to hives to difficulty breathing or even death in extreme cases.
A food sensitivity, also called a food intolerance, is harder to diagnose and there is no accepted definition of this reaction to food. It usually results when a food or an ingredient in a food is poorly absorbed in the digestive tract and results in symptoms such as bloating, diarrhea, skin rashes or hives. Some food intolerances are caused by the lack of an enzyme that may occur with age. Food sensitivity often depends on the portion size. A small amount causes no problem, but a larger amount activates symptoms.
There are no scientifically proven tests for food sensitivities. Those test that are available often give false-positive results which might cause diet modifications that are not needed nor helpful. The best way to diagnose a food sensitivity is to keep a food diary or do a 24 to 48 hour look-back after symptoms occur. Once you discover which food or foods are causing you symptoms, eliminate them for a week or two, and then reintroduce them one at a time to see if symptoms reappear. Go slowly, with small portions at first and work up to more of the food at one meal or snack.
