Blood sugar levels above 180-200 mg/dL for extended periods after eating carbohydrates indicate pre-diabetes or diabetes.

“if your blood sugar raises 80 90 100 milligrams a deciliter or more or stays elevated above 180 or 200 milligrams per deciliter for long amounts of time after you eat carbohydrates you are essentially pre-diabetic or right at threshold or even frankly diabetic you've gone through the door”