Type 2 Diabetes is a disease caused by Insulin resistance.
Insulin is a hormone produced by your pancreas that tells your cells to absorb energy and store fat. Your liver also has a lot to do with how your body stores fat and digests your food.
As we age, and as we gain weight, our cells become more and more resistant to Insulin and our bodies will try to produce more of it. At some point, if we don't change our diet, it becomes too much for our bodies to handle and it can damage our pancreas permanantly.
Many doctors do not understand that diabetes is a dietary issue can be fixed by simply changing how, what and when we eat (all three are important).