Zyprexa is known for causing weight gain and the sleep eating problem is exactly why. I experienced the same thing with Zyprexa and by the time I realized what was going on I gained around 40 pounds. There are other medications such as Seroquel that may or may not cause the same problem for you. I'd suggest talking with your doctor. Let him/her know what is going on and see if there is another med that would be more appropriate for you.