The difference between a food allergy and a food intolerance primarily lies in the body's response. A food allergy triggers an immune system reaction, which can result in severe symptoms like anaphylaxis. Common allergens include nuts, shellfish, and dairy. In contrast, food intolerance typically involves the digestive system, where the body has difficulty processing certain foods, leading to symptoms such as bloating or gas. Intolerances tend to be less severe and don't involve the immune response. Notably, individuals can sometimes outgrow food intolerances, while allergies can persist throughout life.