Though this may be just adding a med to treat side effects, evidence has come to light that the diabetes medication metformin (glucophage) has been used to help against antipsychotic weight gain.

There is something called the Heart Association Type 2 diet I think and I believe that was combined in the study to help as well. They found the combination of the type 2 diet and metformin worked best at countering the weight gain.

Now I don't know what the type 2 diet is and I couldn't find anything really on the internet so this is something that you will have to ask your doctor about.

Because of my post count I can't post links but google "antipsychotic weight gain metformin" without quotes and you will be able to find the article within the first 10 results.

Best of Luck,
Andy...