Yup same here. I lost LOTS and LOTS of wweight when I was on welbutrin. My physician explained to me that welbutrin is a suppressant used for such things as stop smoking, losing wieght, stop drinking and so on besides being used as an antidepressant. which is why the PDR (Physicians Desk Reference (Physicians Medication dictionary) states that welbutrin shouldnt be used for very long for those with eating disorders such as anerexia.

Talk to your prescribing physician and he/she can adjust your dosage and diatary intake so that you dont loose too much weight.