A gluten-free diet eliminates all foods containing gluten, a protein found in wheat, barley, and rye. It is essential for individuals with celiac disease or gluten sensitivity, as consuming gluten can trigger harmful immune responses or digestive discomfort in these conditions. The diet includes naturally gluten-free foods such as fruits, vegetables, meat, fish, eggs, and gluten-free grains like rice, quinoa, and corn. Many packaged foods also offer gluten-free alternatives. While necessary for those with gluten intolerance, the diet requires careful planning to ensure adequate intake of essential nutrients, such as fiber and B vitamins, which are often found in gluten-containing grains.