So your insulin is high, but still in the normal range. It’s understandable that your physician is concerned. It certainly bears watching. If you are staying in the blood ketone range that you posted, then it would seem that your glucagon must also be high, for you to be doing that well in ketosis.
And I beg to correct your doctor. Your HbA1C functions as a three-month average of your serum glucose, but that’s because the average lifespan of your red blood cells is 90 days. What it really measures, however, is how glycated your haemoglobin is, and that is useful to know, regardless of your glucose levels. Yours was borderline pre-diabetic at last measurement, and I would guess that it’s come down a bit, but is still not great. Once you’ve been eating ketogenically for six months, however, I would expect it to be a really good number, unless you are severely insulin-resistant.
Do you have any recent measures of your inflammatory markers (white blood cell count, CRP, ferritin)? This would tend to tell something about your degree of insulin resistance, which I am guessing is still fairly high, hence the high fasting insulin. Your glucose is so nice, because your insulin is pushing it down. But it’s taking a lot of insulin to do so, is my guess.
Tell your doctor to stop bugging you, until you’ve been ketogenic for another four months, at which time he should retest, and get all the numbers I’ve mentioned. It’s far too soon to be making course corrections yet. If your insulin resistance fully resolved, you would see it from really nice inflammatory markers, HbA1C at 5.0 or below, a lower fasting insulin, and glucose levels below 90. Note that after fat-adaptation, glucose tends to rise somewhat, while HbA1C stays low. This is normal and not a problem.
You can tell your doctor from me that he shouldn’t be obsessing about transient variations in your blood work, and that if he really wants to know how insulin-resistant you are, he should order an oral glucose tolerance test (OGTT). (Be sure to tell him I was smiling as I wrote that.) And no, I’m not a doctor, but I’ve learned a fair amount from hanging around with smart people.
No, and you probably shouldn’t be attempting one meal a day, this early on. Once you find yourself skipping meals because you’re not hungry, or especially if you keep forgetting to eat (“accidental fasting”), then it’s time to think about fasting on purpose. Till then, listen to your body.
P.S.–It’s great that your doctor wants you in ketosis and fasting, but listen to your body. Too much too soon is counter-productive. Tell him that for me, too!