The development of type 2 diabetes is directly related to lifestyle factors. Overweight, obesity, unhealthy diet and lack of exercise are strongly correlated to the development of type 2 diabetes.
A diet with a high inclusion of simple carbohydrates, especially processed sugar, is the biggest dominant causative factor. Constantly elevated blood sugar levels trigger the cycle of high insulin levels, which causes the cells to become insulin-resistant.
It is believed that people with a family history of Type 2 diabetes have a higher risk of developing the condition. However it is not clear if this is related to the genetic factor, or because members of the same family tend to follow the same lifestyle patterns, or both.