What kinds of foods should I eat to bring up my potassium level?

Potassium blood levels must be maintained within a very narrow range. Too little potassium or too much potassium can both cause problems.

I had blood work done recently before having surgery.  I was told that my potassium level is low.  What kinds of foods should I eat to bring up my level, without raising my blood sugar level?  I have type 2 diabetes.