Type 1 diabetics can’t put on fat without insulin injections. I already explained why, if you don’t believe me open any random textbook on metabolism.

As Type 1 diabetic to lose weight all you need to do is stop insulin and live your life, sooner or later all the fat will be gone: Under normal circumstances we’re always burning a little, regaining a little, as Type 1s can’t gain without injections you’d only lose.

On the flipside doctors will try to make sure that Type 1s do have enough fat on them to survive for a while, mortality rate before insulin was discovered was insanely high: Eat something and lose consciousness because your blood sugar is too high, don’t eat enough and you’ll starve sooner than later, hard to strike a balance there without any help from modern medicine.

As Type 2 it’s not really harder to lose weight than as a non-diabetic, thing is though people who become type 2s generally have lifestyle (and/or other) issues that brought them there in the first place. Correlation, not causation.