Effect of Increased Physical Activity and Stopping Evening Snacking in Metabolic Health in Youth With Prediabetes

Insulin sensitivity index for glycemia (ISI \[Gly\]) will be calculated with a formula using insulin and glucose area under the curves during oral glucose tolerance tests (OGTT) as described previously (Belfiore et al., Metabolism, 2001): ISI (Gly) = 2 / \[INSp x GLYp) + 1\] INSp: insulinemic area during OGTT with 3 (0, 1h and 2h) or 5 sampling (0, 30, 60, 90 and 120 min) GLYp: glycemic area during OGTT (0, 1h and 2h) or 5 sampling (0, 30, 60, 90 and 120 min) INSp and GLYp are expressed by taking the mean normal value as 1, i.e., by dividing the value observed in the person under study by the mean normal value so that, if INSp (or GLYp) is 1.5-fold the mean normal values, it will be considered as equal to 1.5, and so on. We will use appropriate "mean normal values," which will be derived from data obtained in our laboratory.