I would guess that a really small wafer would probably not be a problem diet-wise but if it's a large wafer it could be problematic. If it's "bite sized" then it's probably fine.

Besides, remember that this is a way of life (WOL), not a "diet." If going to Church and taking the host is important to you spiritually, then I wouldn't recomend abandoning it. It's part of your life.

Now, if there's a huge potluck after services are over, THAT'S when you need to exibit self control!