A food allergy is an abnormal immune response to specific foods, which can lead to various symptoms, including anaphylaxis, gastrointestinal distress, or skin reactions. Such allergies can affect fitness by limiting dietary options and leading to potential nutrient deficiencies if not managed properly. Athletes with food allergies must carefully plan their meals to ensure they receive adequate energy and nutrients. Ignoring allergies can hinder performance due to adverse reactions that impact health and stamina during physical activities.