Last month I had my 1st fasting blood sugar, it was 104mg/dl. Afr 1 month of diet and exercise it came down to 81mg/dl. Is it good? Am I prediabetic?

Very good, no longer. Excellent job with diet and exercise. At 104 you qualified as prediabetic but now your sugars are well within the normal range, so as long as you maintain a healthy diet ; exercise you are no longer prediabetic. But ron rosedale, a diabetes specialist, says we are all prediabetic in the sense that anyone might develop diabetes unless they maintain a healthy diet ; lifestyle. Keep up the good work!