Supposedly the best way to determine insulin resistance is a Five hour Glucose Plus Insulin resistance test. Almost no doctor will order that if there is even a lab that does it.

There is a much simplier and quite inexpensive Fasting Insulin Test that some doctors use, and then they plug that and fasting glucose into the HOMA-IR formula. HOMA-IR stands for Homeostatic Model Assessment of Insulin Resistance. The meaningful part of the acronym is “insulin resistance”. It marks for both the presence and extent of any insulin resistance.

It's not perfect, a LC doctor needs to interprete the HOMA-IR score in the context of your overall health, but it does explain why some "think" LC causes insulin resistance.

Dr Naiman's terrific post on this seemingly contrary but perfectly normal result of LC eating:

https://www.dietdoctor.com/fasting-...l-high-low-carb

I would not assume this is what is happening with you until you have Fasting Insulin tests consistently under 5 for a period of time. Since there is no home test for Insulin, so usually only tested annually. If remembered correctly, after about two years of VLC I was at a healthy BMI and in that range. EDIT: My insulin was 9.6 near the start (but after having been LC about 6 months so that is not a real baseline), under 5 since, 3.6 last tested. I am the classic example used in this post. My FBG hangs around 100 but with a 3.6 insulin, HOMA-IR is .88. Multi-day fasting will drop my FBG much lower, and a longer pre-blood draw fast also dropped my insulin "below normal" (works , but not recommended )

Great Video on IR:
https://www.dietdoctor.com/member/p...dge#more-830243

And the Very Simplest and Free measures of Insulin Sensitivity is a Waist to Height ratio less than .5. Dr Naiman discusses his measures in his video.

http://www.thefatemperor.com/blog/2...8gxxvi5xklrzr2c

how to measure: https://www.dietdoctor.com/simple-w...lth-measurement