First of all, make sure you communicate your dietary choices with your doctor and psychiatrist. That will ensure your choices aren't interfering with your medications, they may have some recommendations that will fit within your desired plan.

Secondly, talk to them about Metformin. I'm not sure about this medication and Depakote but it is worth asking them. I am on Seroquel which tends to cause weight gain. While Metformin is in fact a diabetes medication more and more doctors are prescribing it off label for the management of weight gain owing to some psychiatric medications. Some complain about become far to 'regular' as a side effect but I've personally haven't experienced this. My weight is now under control, I've even lost a little. The important thing is that I am no longer gaining 3-5lbs per month anymore.