Agreed, that seems like a very dangerous idea just to try and enhance your insulin spikes with CBL…

Kiefer actually said he's talked to be people (advanced athletes) that have done it.  He does not recommend it.

I know people who have used it, though not with anything like CBL. It works, you can do a lot with it, but I agree with Kiefer that I would never recommend it.

I wonder what kiefers beef is with it.

Same reason we just mentioned.  It's dangerous and unhealthy.

As others have said, using insulin incorrectly could kill you. It's very easy to use too much insulin, become dangerously hypoglycemic, and go into a coma. As a diabetic, I have to use insulin occasionally (though the combination of proper diet and tons of exercise usually obviates the need for injections). Despite being careful and following doctor's orders, I have become dangerously hypoglycemic on multiple occasions. You never know how your body will react to the insulin. Sometimes, a few units is just right; other times, a few units will knock you on your ass (I've been using insulin to varying degrees for nearly a decade and still get nasty surprises from time to time). Furthermore, nondiabetics who inject insulin risk developing insulin resistance and type II diabetes. Health threats aside, using insulin incorrectly will make you fat very, very quickly. Avoiding some fat gain is nearly impossible when you use insulin. If you use insulin and don't nail your nutrition perfectly all the time, you're screwed. But it can be really hard to maintain a perfect diet when you use insulin. For example, if you use too much insulin and become dangerously hypoglycemic, you have to ingest a bunch of carbs to get back into the safe zone in a hurry. There go your macros for the day--especially if it's a ULC day and you're trying to stay below 30 grams of carbs.  You're just asking for trouble if you start messing around with insulin--no matter how careful you are. The risks far outweigh any of the minor potential benefits.