prediabetes is diagnosed when your blood glucose levels begins to venture out of the normal zone. prediabetes brings an elevation of fasting blood sugar to 100-125 mg/dL. when you have a diagnosis of prediabetes, that means you're on the fast track to developing types 2 diabetes unless you take steps to reverse it. think of the diagnosis of prediabetes as a blessing, which is irreversible. although it is known that diabetes can be prevented or delayed among adults at high risk through modest weight loss and increased physical activity, a study published in the April 2010 issue of the American Journal of Preventive Medicine revealed that only half of America adults with prediabetes reported attempts to lose weight or exercise more in the past year.