My mother in law had had diabetes type 1 (so yes, she used insulin injections). She had actually lost weight (26 lbs) on Dr Bergs diet (which when she lived with us) I prepared for her/us (which was the low carb/keto diet).
She was staying with us while her home was being built for both her and her other son's family in another state (thats where she was to stay permanently). But she stayed with us for nearly a year. I watched her progress even with Diabetes 1 and she was able to reduce her injections even during that time.
I tell you this because there was something about her medicare coverage that she could not be out of the state she lived in for over 6 months (for whatever reason, I do not know) and her home was taking longer than they anticipated to build, so we had to fly her back to her home state just so she could set foot on it to keep her coverage (or something to that effect, it made no sense). And while she was there she visited her doctor, who was amazed when he saw her and tested her and said, whatever you are doing keep it up! He said, may I ask what you have been doing? And she told him my daughter in law (which was me) has me on a diet by a Dr Berg.
After he heard that he told her, "No no no, you cannot be on that quackery" and introduced all sorts of doubts into her mind about it (even though he himself just praised the results he was seeing in her). When she returned to us she looked concerned that she should not be on it, although she doubted her doctor for the first time because she felt so much better, lost weight, had more energy and was taking far insulin and her blood glucose levels were so much better than they were before.