No, celiac disease typically does not cause weight gain. One of the common symptoms of untreated or undiagnosed Celiac Disease is unexplained weight loss. The inflammation and damage to the small intestine lining interfere with the absorption of nutrients, leading to malabsorption and weight loss. People with celiac disease often experience gastrointestinal symptoms, such as diarrhea, abdominal pain, and bloating, rather than weight gain.