Yes.
Insulin has several jobs in the body: the best known is managing Blood Glucose - by balancing (or "covering") the amount of carbs you eat at each meal with insulin you can maintain better BG levels, which is clearly a good thing

. BUT it is a careful balancing act; as too much insulin increases appetite, and is also responsible for laying down fat stores and preventing them from being burnt as fuel... thus the weight gain
I believe the trick is to limit the amount of insulin you require to maintain a normal BG, by carefully limiting the amount of carbs and sugar that you eat.
