If you are pre-diabetic the number that a Dr uses is A1C which looks at the level of your blood gluose for the past 3 months. I'm diabetic and while my Dr does a fasting glucose he isn't quite as concerned with that number as the average. Do you know what your A1C is?
For a diabetic it's more important to cut back on carbs and exercise. Recommended amount is at least 30min 5x a week. Don't forget to drink lots of water as well as it flushes out the sugar.