Exercise, exercise, then more exercise. Five times a week, nothing
strenuous, even a simple walk will do. I find it's much more important than the foods you eat - what your body does with the food you eat, I mean.
Also, a waist size of more than 38 (I think) inches puts you at a far greater risk for developing Type 2 diabetes.
Also look for early symptoms such as weight loss, thirst (both warning signs for Type 2 diabetes), and believe it or not, high blood pressure - doctor said blood cholesterol levels, blood pressure, and blood sugar levels are all interrelated.
Good luck.