It all depends on your body and how sensitive you are at that time. As you use it, you will get used to the insulin and you might be able to get away with less, but the only way to know is to start with 10g per IU and then start reducing. After you are sure that 10g works, then go to 9g and so on. Just keep some simple sugar on hand, in case you start to go hypo. Keep in mind though, the idea of using insulin, it that it allows you to utilize more carbs more effectively. Insulin is a storage hormone, plan and simple. So the idea is to use it to make better use out of large quantities of food. So for me, the question is never how few carbs can I use, but how many more can I add! Remember, insulin works very well and you can end up storing a lot more fat than you would otherwise. So if you are prone to getting fat, insulin may not be the right tool for you. Its best for guys that are ecto and struggle to gain muscle. 

For anyone interested in working one on one with me, message me at the Next Level Nutrition page, here at Naps. I will build you a plan based off your goals, expereince and lifestyle.