Hi. I have a son aged 17, who has had Type 1 for 5 years.
I think you will learn over time, that different foods break down at different rates. For my son, brown rice would be very slow and therefore the insulin would be at its peak effect 1-2 hours after the dose, but the rice would barely have hit his system - resulting in a low blood sugar and a high blood sugar hours later. The trick is to learn to match up the dose to the food, with a combination or carb-counting so that you can select the appropriate number of units to give and by timing the dose according to the sort of food. This may sound daunting at this stage, but with support from your team and more experience, you will become an expert. If you haven't already got it, I strongly recommend getting a copy of Ragnar Hanas's book 'Type 1 Diabetes in Children, Adolescents and Young People'.