Julie’s Blood Sugar Changes Throughout the Day After an overnight period of not eating, Julie's blood sugar is relatively low at 70 milligrams per deciliter (mg/dl). After breakfast, which included peanut butter toast, a banana and milk at 7:30 am her blood sugar went up to 110 mg/dl. Julie had a math test at 9: 00 and did very well. Her blood sugar gradually decreased until lunch at 11:30. Julie ate a turkey sandwich with low fat chocolate milk, an apple and 2 chocolate chip cookies. Her blood sugar went back up to 110 mg/dl. Her blood sugar decreased a little bit until she had a snack at about 2:45 pm. Julie had the snack because she knew volleyball practice would be strenuous, and she wanted to fuel her muscles. Julie's blood sugar dropped pretty quickly by 5:00 pm because of her workout. For dinner she had a hamburger on a bun, peas, a side salad and low fat milk, which caused her blood sugar to go back up. There was another decrease until her snack of vanilla frozen yogurt with strawberries at night which brought her blood sugar back up again. After 10:00 pm we can expect her blood sugar to gradually decrease to 70 mg/dl until breakfast the next morning.