Those who do not have celiac disease (gluten allergy) probably have not noticed how many different foods have gluten in them. But those who are allergic know exactly what to avoid. Wheat gluten is a protein that is found in wheat as well as some other grains. You will see it in pizza, pasta, bread, and even beer. Gluten is not bad for you, per se, unless you are allergic. However, eating excessive foods with wheat gluten can cause weight gain.