Dear sir i can understand your concern i can understand your concern i would like to explain a small concept called glycemic index. The glycemic index (GI) is a ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise blood sugar levels after eating. Foods with a high GI are those which are rapidly digested and absorbed and result in marked fluctuations in blood sugar levels. mango fall in the group of high glycemic index foods so by taking this high glycemic index food in excess quantity can fluctuate your blood sugars. take balanced food and go for exercise to regularize your diabetes. hope this explains your query Regards