Having a normal fasting blood glucose DOES NOT mean non-diabetic! In fact majority of diabetics have normal fasting glucose!!
This was discovered by Dr Joseph Kraft in the 1970s. He designed a test called the Kraft's Test which measures how insulin-resistant one is. Insulin resistance develops slowly over a period of decades. One can determine how insulin resistant one is using the kraft's test.
What is the Kraft's Test?
1. Consume 100 gms glucose drink in the fasting state.
2. Measure serum insulin levels at 0, 0.5, 1, 2, 3, 4 hrs.
3. The pattern of insulin response to 100 gm glucose challenge determines how insulin resistant one is.
4. Stage-1 people are non-insulin-resistant (perfectly normal glucose metabolism) and stage-5 people are fully diabetic. People in stages 2,3,4 are progressively more and more insulin-resistant.
5. With proper treatment, a person in stage 4 will regress to stage 3, then stage 2 and then finally come to stage 1.