Weight loss is also more common among people with Type 1 Diabetes, Doherty says. The loss of calories is due to frequent urination. You lose a lot of glucose that way. “The body doesn’t store it and other good stuff properly anymore,” she adds. The sugar is not getting to the cells for storage. When diabetics are given insulin to better control their blood sugar, they retain more of it in their cells and this can lead to weight gain.