Dr. Jason Fung explains the causes and non-pharmaceutical method of treating Type II Diabetes here:
OK, you say, but what about Type I Diabetes? Is it simply a matter of taking insulin, or are there other, complementary treatments that can be used by the diabetic?
This blog post says yes, there are other tactics. Low Carb High Fat diet is also helpful for Type I Diabetes. You say this contradicts your doctor's advice? Perhaps. But read the post all the way through before deciding if it makes sense for you.