Hi Heather,
Type 1 and Type 2 seem to be different and they don't know what clearly waht causes them though definitely there is a genetic predisposition.
Type 1 seems to be autoimmune and results in the pancreas B cells being destroyed. What triggers the autoimmune reaction, in some cases an illness, pregnancy, and other cases unknown. Insulin is always required as treatment.
Type 2 has insulin resistance as a major factor and lifestyle plays a big role, though there could also be something autoimmune going on. Weight normalisation, exercise and lower carb diet can be very helpful and even arrest or apparently revers the condition. However, if long term high blood sugars persist B cells can also be destroyed and insulin is required..
Do you think that we are born with a defect in our pancreas, that either presents early in childhood as Type I or starts acting up later, as Type II? I know that family history plays a large part, but so does our lifestyle.
If you are type 2, the diabetes can often be very well managed with low carb diet and exercise (read Dr. Richard Bernstein's "Diabetes Solutions").
However, if your pancreas is not working then insulin or meds are the way to go, in addition to diet and exercise management.