I don't know if it's the same for us but when people would use insulin for muscle growth they tend to put on a good amount of fat. Usually this also increases visceral fat which is harder to lose if there is insulin resistance. But again don't know in what way this affects us. Furthermore visceral fat is in some ways connected to insulin resistance.
This all said the basis for losing weight is the same for diabetics and non diabetics. As a non diabetic would consume more carbs he would demand more insulin from his body and stack on some weight. Same for us though we supply the insulin ourselves. So generally eating less carbs will decrease your need for insulin and make it easier to lose weight. This and a moderate exercise program would help you well on your way.
On the other hand there are factors that can decrease your ability to lose weight. Your body type, age, not getting enough sleep, ... the list goes on. So if you're sure that on your current diet/exercise regime you should be losing weight and you're not it's worth looking into other things that might have an effect. There are plenty of pitfalls when you're trying to lose weight and it's a bit more tedious for us. Just think of doing a great workout and then having to drink double the amount you burned in calls because you suddenly have an hypo. So having your BG under control is a step more we have to take as opposed to non diabetics. And you can expect a bit of trial and error before you properly start to lose weight. For me i usually lose a couple the first week or two then stagnate or even rise again for a good week or more and then it starts going down in a straight line, but everyone will be different in this.