The type of basal testing we usually do seems to work out better than when we do fasting basals. Fasting basals are lower than the basals needed when she is eating food during the day. What works for us is to do a fasting basal starting four hours after dinner, continuing overnight and sleeping as late as possible. That’s an easy basal to get. For the rest, I give scrambled eggs, decaf tea, string cheese. Then a late lunch. This basal will cover the morning period until about 2pm. When testing basals during the lunch and dinner period, I give sliced chicken, salad, string cheese, make a large pot of home made chicken veggie soup, no noodles. For us, basals gotten in this method are more reliable than fasting basals. During a growth spurt, which happened frequently during puberty, we would double and even end up tripling basals for evening/early a.m. hours and basal testing did not help.