Dietitian Cynthia Sass writes that people often make mistakes when experimenting with a gluten-free diet because they do not understand what gluten is or the products that contain the protein. She says some people equate gluten-free with weight loss and others focus on gluten-free junk food and ignore the rest of their dietary needs. "In people who have celiac disease, consuming even small amounts of gluten triggers unwelcome symptoms, including belly pain and bloating," she writes. Such patients must avoid gluten, but others may benefit as well, Sass notes. "People like me, who test negative for celiac disease, may be experiencing a condition called gluten intolerance."