"I looked at a site about celiac disease and the only weight problem they mention was losing it. I do have some of the other symptoms, but not that one. Can you have celiac and be 100 lbs overweight?"

Yup.

Your body can't absorb the nutrients it needs while it is being ripped up by the whole gluten-thang. So it keeps telling you it is hungry, and you eat and eat and eat. Desperately trying to get minerals and vitamins, your body only manages to absorb a ton of calories and it's still starving!

A lot of folks with celiac will lose excess weight very quickly once they get the ALL the gluten out of their menus. Their intestine heals, and suddenly (within a couple weeks) they can absorb nutrients again. They aren't starving for trace elements any more, so they aren't as hungry. Some are still very difficult to absorb (vit D and vit B12 especially) but some over-the-counter supplements take care of that. (sometimes in massive doses, but that depends on what your doctor recommends)