A test method that helps identify foods that may be causing a reaction in an individual involves the individual entering into a computer a daily log of all the foods they routinely eat and any reactions that they may experience. The reactions may be headaches, fatigue, physical pain, depression, etc. The test method can be done without the individual having to follow any prescribed diet. After recording several weeks or months of data, the computer analyzes the data to determine if any significant mathematical correlations exist between a reaction and any of the foods, whereby a high positive correlation may suggest that the food is perhaps related to the reaction. In addition to food items, the method can analyze the correlation of other influencing agents such as environmental exposures, inhalants, menses, and stress.