It's common in foods such as bread, pasta, pizza and cereal. Gluten provides no essential nutrients. People with celiac disease have an immune reaction that is triggered by eating gluten. They develop inflammation and damage in their intestinal tracts and other parts of the body when they eat foods containing gluten.

What happens if you don't eat gluten?

Common symptoms are diarrhea or constipation, vomiting and weight loss, malnutrition, anemia (low levels of red blood cells), tiredness or fatigue, bone or joint pain, depression, stomach bloating and pain, and short stature in children.

Can you survive without eating gluten?

"You can eat a healthy diet without gluten, but you have to be very knowledgeable, and most people aren't," Tallmadge said. People who go gluten-free may feel better because, to avoid the protein, they end up cutting out desserts and junk foods, thus losing weight.