Insulin lowers blood sugar and must be administered by people with type 1 diabetes before each meal. So called hybrid closed loop systems are insulin pump systems that to some extent determine the insulin dosage themselves. In order for these systems to accurately estimate how much insulin is needed after a meal, the user must estimate the carbohydrate content of the meal very precisely. This can be time-consuming and challenging.

In this study, we test whether a simplified estimate of the carbohydrate content of a meal (small, medium or large portion) can achieve similar blood glucose control as when the exact estimate is used.