MedPage Today has a brief article on “diabulimia,” a disorder in type 1 diabetics who withhold insulin in order to lose weight.
After following the women for 11 years, the researchers found that those who restricted insulin had increased rates of diabetes complications, shortened lifespan, and increased mortality risk.
Factors that were associated with insulin restriction included greater eating disorder symptoms, diabetes-specific distress, overall psychological symptoms, and fear of hypoglycemia at baseline.
Diabulimics believe the theory that insulin is a major fat-storage hormone. Furthermore, the high blood sugar levels resulting from inadequate insulin dosing lead to loss of calories (sugar) via urine.
Paleo Diabetic 
Someone needs to tell Stephan Guyenet;
Gary Taubes already knows.
– In the video, Hunt said that the heightened attention to food associated with managing type 1 diabetes is a risk factor for diabulimia. In addition, insulin promotes weight gain.
The more one has control over blood glucose sugar, the less progressive their weight gain, Garber said. But patients often overcompensate. “It’s a trap for weight gain,” he said. “If you’re prone to low sugar, the extra insulin puts on even more weight. But these women realize that if they withhold or reduce their insulin, they will excrete the sugar and keep their weight down.”
I’ve see this practice common in young type I diabetic women, especially.