A condition in which the immune system reacts to substances some foods?

The correct answer is Food allergy.

Food allergy is an immune system response to certain foods. When a person with a food allergy eats the offending food, their immune system overreacts and produces antibodies called immunoglobulin E (IgE). These antibodies attach to cells in the body called mast cells, which then release histamine and other chemicals. These chemicals cause symptoms such as hives, swelling, difficulty breathing, and vomiting.