Tests and Diagnostic Techniques
There are three main problems with foods that an individual can experience: food allergies, food sensitivities and food intolerances. All of these can be identified through an allergy elimination diet that may be followed for four to six weeks. After this time foods are added back into the diet while the individual watches for food allergy symptoms that may develop such as a drop in energy, muscle aches and pain, headaches, mood changes, bowel changes or stomach pain.
Skin testing for allergens (called RAST testing) is only useful for allergies where the body makes a specific antibody called IgE. But many times the antibody made against foods is IgG making the skin test largely ineffective at measuring food allergies.
A blood test can be used to detect food allergies by looking for both IgE and IgG. A blood sample is taken and sent to a lab where chemicals are added to the serum, which bind to and detect the blood antibodies.
There are other tests available for food allergies and sensitivities such as the Vega electronic test.