I’ve been eating zero carbs Feb 2022 and since Sept 2022 started higher fat carnivore. I’m trying to reverse pre diabetes. I had A1C of 6.2 then went down to 5.9. My most recent blood work was to 5.7. I track my fasting bs and post meals bs really closely. Since going higher fat, I found that my protein threshold is about 20ish gram per meal with lots of added fat. I feel best that way. And glucose doesn’t spike too often if the protein is portion out.
Lately I found that I have become more obsess with recording the glucose and would get frustrated if the numbers would spike to low 100s fasting and after meals. Given that now I’m already lowering protein portion per meal in order to help with spikes.
I don’t want to lower my daily protein intake any lower with fear of muscle loss. So the question is knowing that I’m already eating zero carb, should I just don’t stress too much with the higher readings? I know body goes through gluconeogenesis and only makes glucose when body needs it. Do I just continue and trust the process and my body?
Glucose readings on zero carb
Firstly, glucose is supposed to go up and down. It’s supposed to stay within a fairly narrow range, of course, but Dr. Paul Mason believes that the absolute level is not so important as avoiding large swings. If we could test insulin at home, you’d see the reason for that.
Second, if the error margin of your home meter is ± 20%, then a blood sugar of 90 and a blood sugar of 100 are essentially the same.
If you are carnivore and you’ve been doing it long enough that your glucose has started to rise again, one possibility (as Amber O’Hearn suggests) is that you aren’t eating enough fat to meet your body’s energy needs, so the liver is making more glucose in compensation. That is a possibility, though not the only possible explanation, I hasten to add.
Along with @PaulL’s point above, I’ll add that many folks who, like you, stay on keto who carefully track serum glucose report that, over time, their baseline glucose levels gently rise to some extent. [E.g., mine wandered up from around 80’ish (dawn effect) to about 90-100’ish (dawn effect).]
Again, the most important consideration is how significant are those glucose swings and how quickly do they dissipate?
Large and longer-lasting excursions from “base” can tell a meaningful story about the extent to which your body is being flooded with insulin and the extent to which your tissues/muscles have become insulin-resistant (i.e., pre/T2D)
Somewhat elevated serum glucose as a baseline is very common, quite normal, and believed to be a healthy outcome by many who’ve looked closely at it. It’s a change in the supply vs demand dynamic.
In short, you are now seeing glucose levels that reflect your body’s natural demand (via GNG) for glucose it can produce from body fat, not the amount of glucose circulating from dietary supply (carb ingestion). It’s all good!
The other (somewhat esoteric) point worth noting relates to the calculation of HbA1c: The calculation presumes an average (90 days?) life span of red blood cells. To the extent that red blood cells are believed by some to “live longer” when dietary carbs are restricted, they are around longer than otherwise and pick up more glycation (thereby biasing upward the numerator that goes into the HbA1c metric).
In your case, the fact that your HbA1c is falling despite what may be longer-lived red blood cells also indicates that you are meaningfully improving your metabolic health through carb-restricted diet.
Kudos on your success thus far!
Thanks for the response. I do follow Amber O’Hearn’s higher fat way of eating. I feel great eating 80% if not higher in fat. Could fat be broken down to glucose from the glycerol back bone and cause my glucose to increase as my fat increase? I might’ve heard that somewhere but can’t remember from whom.
Thanks. My glucose pre meals and post meals are usually in 90s - low 100s. Sometimes 80s. It never goes any higher than 120 and that’s a rare case. Can I assume that those are within good ranges?
With my recent lab work, I had requested a fasting insulin as well. It was 1.5 which is reassuring for me. Can I assume that I’m now insulin sensitive and trending in the right direction for my health? Should I not worry too much with glucose after meals. I eat the same foods pretty much day in and day out with zero carbs.
FWIW, you’ve described perfectly how my own serum glucose levels now behave with 4 yrs of keto. After initially causing a little angst, I did oodles of reading/research on the topic (which has not yet been perfectly RCT-tested) but I’m perfectly satisfied it’s all healthy - and far better than any alternative.
As a result, I rarely even bother testing anymore, besides the occasional n=1 experiment to see how I respond to a particular food item, if ever.
My $0.02: Yes, you can assume you are within good ranges.
Since your glucose meanders within a narrow range and presumably comes back from your not-so-high max down within a reasonable timeframe and your HbA1c has trended downward, it sounds like you’re quite insulin-sensitive and doing fantastic.
Enjoy those hearty keto meals! 
Good move (assuming) it’s not already to low. You said your protein “threshold” is 20ish a meal? So 60g a day? If so that’s already super low.
Define “spike”, most people that become obsessed with recording glucose call everything a spike, most of which is just transient rises and drops.
On this, you’ve failed. Gluconeogenesis being a problem is LONG debunked, the days of the beleif of “too much steak turns to cake” are behind us. It’s demand driven, not supply.
Then you’re not dealing with spikes in any way, that’s barely moving.
Thanks for the responses. My protein usually anywhere between 65-80 g per day give or take. I’m only 4’11 and weigh 114.
That’s a speculation, but I don’t know whether it’s true or not. As you can tell from the names, glycerol and glucose are chemically related.
I do know that the glycerol does get reused a lot. Every time a bunch of fats needs to pass through a cell wall, the triglycerides need to be broken down, the ingredients moved to the other side of the wall and then the triglycerides get reassembled.
But if the glycerol gets turned into glucose, that would simply mean that the liver doesn’t have to make as much glucose by means of gluconeogenesis.
The only way to be absolutely sure is by means of an oral glucose tolerance test, in which you are given a measured dose of glucose, and your glucose and insulin levels are measured at baseline and at thirty-minute intervals over the next several hours. From the glucose and insulin curves that result, it is possible to diagnose insulin-resistance, often as much as two decades before a diagnosis of Type II diabetes is made. (Nobody likes to do this test, because it’s labour-intensive and therefore expensive.)
However, if your HbA1C is under 5.5 and your ratio of triglycerides to HDL is under 1.0 (U.S.) or 0.5 (rest of the world), then you can be pretty sure you are insulin-sensitive.
If insulin-sensitivity is of interest, a somewhat less disruptive and probably cheaper way to get gain insight might be from an NMR Lipid panel - inasmuch as lipid particle size profiles suggest a good bit about sensitivity vs resistance to insulin.
Not perfect, but easier than gulping syrup and taking blood tests every 30 minutes.