The best way to check for food allergy is first to keep a diary and correlate the symptoms of discomfort perceived by you at your age. If food allergy is suspected, and if you do not know which food is causing the problem, skin tests for all food items will be practical. Blood tests for all items of food can be very expensive. When I say blood tests , I mean tests for IgE antibodies such as RAST tests. Many tests based on detection of IgG antibodies are not always clinically relevant – the tests may mean nothing to your in your situation. Once identified avoidance and challenge will be helpful to decide if it is relevant to you.