Gluten is a natural protein found in wheat, rye, barley, oats and triticale. It acts as a kind of glue, helping foods hold together and maintain their shape. Eaten on its own, gluten has a chalky taste, comparable to corn starch.
Common foods containing gluten include breads, baked goods, pasta, soup, cereals and food coloring. There is no way to identify foods containing gluten based on appearance or coloring.
People with celiac disease have an allergy to gluten and must eat a gluten-free diet to avoid symptoms such as fatigue, diarrhea and headaches. For people without gluten sensitivity, eating a gluten-free diet is not healthier than more traditional diets, according to WebMD.