A gluten-free diet involves avoiding foods that contain gluten, a protein found in wheat, barley, and rye. People with conditions like celiac disease or gluten sensitivity may experience adverse reactions when they consume gluten, leading to digestive issues and other health problems. Foods that are naturally gluten-free include fruits, vegetables, meat, fish, dairy, and grains like rice and quinoa. Many processed foods are also available in gluten-free versions, allowing those on this diet to enjoy a variety of meals while maintaining their health.