What's the goal of diet therapy for diabetic?

Diabetic control: The goal of diet therapy is the same as the goal of pharmacologic therapy: glucose control. Typically, glucose control is assessed by the hemoglobin a1c. This test gives an estimate of average blood sugar over a 3 month period. For most people a value < 7% is considered to be controlled. If you're asking about weight loss, a reasonable goal is to lose 5-10% of your body weight.