What foods should I avoid in order to avoid a 'diabetic' situation? I have a family history.

Sweets. Soda, alcohol, sweets. Foods with the highest glycemic index include bananas, grapes, raisins and corn, so you want to limit these too. Maintain a healthy weight with a BMI less than 25.
Carbohydrates. You should avoid large amount of carbohydrate and high glucose index food. Eat more veg and fruit.