decreased appitite but did anyone have an increased appitite or gain weight because I wont take it if it makes me gain weight

Zyban is basically wellbutrin marketed for smoking cessation. I took that, and I did not gain weight.. although the other side effects are worse.. some people get really paranoid and some lose sexual appetite or it increases... read the risks, some people get suicidal, etc...
weight gain or loss is the least of your worries with that stuff...

I was on Wellbutrin....mainly for depression tho. They use it to quit smoking and maybe weight loss too which are both things that went along with my depression. Me personally, I didn't have any neg. side effects. No weight gain, head aches, sickness...nothing. It really helped with the depression and smoking.....but it didn't seem to have any effect on decreasing my appitite. I still ate the same.

http://www.anxiety-and-depression-soluti...
You should really read this.

Most common are headache and tummy upset. Side effects will usually go away in 1-2 weeks. If they are bothersome or do not go away you may want to try something else. The great thing about Wellbutrin (Zyban) is that you feel a little better the very first time you take it. It will take a couple weeks for the full effects. If your appetite is huge or small before you start, it may change for the better when you are feeling better. In general, people do not get fat on it so don't stress! t also does not interfere with sex drive like some other SSRI's do. Wellbutrin/Zyban is an antidepressant first and foremost. Yes, it is also used to quit smoking.
From Davis's Drug Guide for Nurses:
ADVERSE REACTIONS AND SIDE EFFECTS*
*CAPITALS indicate life threatening underlines indicate most frequent.
CNS: SEIZURES, agitation, headache, insomnia, mania, psychoses.
GI: dry mouth, nausea, vomiting, change in appetite, weight gain, weight loss.
Derm: photosensitivity.
Endo: hyperglycemia, hypoglycemia, syndrome of inappropriate ADH secretion.
Neuro: tremor.