Johnny, when you're prediabetic, your blood sugar goes up and the pancreas works faster and produces more insulin to be able to keep the blood sugar at a normal level but sometimes, it produces too much insulin and your blood sugar goes down too low.
Eventually, the pancreas gets tired of working so hard and slows down and the blood sugar goes up and now you're a diabetic.
First of all, when your doctor says you're close to diabetes, what does he mean? How high was your blood sugar?
By the way, drinking all that fruit juice is not a good idea. Fruit juice is sugar. That's why when diabetics have low blood sugar we give them juice.
So you're drinking a bunch of sugar and juice will only last you about half hour and if that's the only thing you had then in half hour your blood sugar will come crashing. You need to have protein. It will last you much longer and won't cause a big spike in blood sugar.
P