Does Insulin Causes Weight Gain?

I have type 11 diabetes, I feel very good for my age almost 70, and have rarely had a sick day in my life, I walk a mile every day now, and feel even better, I have lost about 38 lbs with about 18 more to go, I cut way back on almost everything, my sugar levels are down to 180 the highest they ever were that I am aware of while testing was 332 after I had eaten a large meal prior to the fasting Blood test. When I was diagnosed. I am currently on oral meds. and wonder if I will have a problem loosing weight after I must go on insulin down the road. I have heard that insulin causes weight gain is this a fact?