Seriously, how do you maintain your weight when taking an anti-psychotic?

I'm on Zyprexa and Lithium and I put on about a kg a week. Didn't have a weight gain problem when I was just on the Lithium. I go on the treadmill everyday and most weeks I eat fairly healthy, I'm vegetarian so that eliminates most take out food but I only lose weight when I think I'm under eating.

Sigh. People think I'm f***ing pregnant with the gut I have now! :'(

All my clothes don't fit. What's the best why to hide a gut. High waist skirts? I don't know how to dress anymore. I just look fricken fat. >>

So close to just having water and celery sticks everyday.