This means adding another medication, but 2 come to mind. You could try the antidiabetic medication Glucophage (generic metformin), or Topamax (as a side effect of the drug is weight loss; it's generic now too in the US).

As always diet and exercise precedes using medication.

Recommendation: If you have a Wii, get the Wii game called Just Dance.

It will really help in keeping you moving when you play the game.