Curiously weird BG and ketone readings


I have been doing keto pretty religiously now for six months and have done several 36 and 42 hour fasts. This last month though I must admit I have been doing “Lazy Keto” and just making sure my carbs were low (20g or less) and then eating till I wasn’t hungry. On the 4th though I went off the wagon and ate some things with sugar and such, and maybe a little too much vino… Anyway, I am now on hour 37 of fasting after my 4th of July celebration. I have been taking my blood measurements since I woke up this am, and my blood glucose continues to climb and my ketones drop. I woke about 4 hours ago. Upon waking my BG was 102 and my ketones were 1.2. Now, they are at 110 and .8 respectively. I have had nothing to eat, only black coffee (2 cups) and water.

I use the keto Mojo, and I assume that is accurate. Any thoughts? I plan on fasting till these numbers start going in the right direction. That might mean 42 hours, maybe 48, or who knows?

(Full Metal Keto) #2

This sounds like the dawn effect, BG is naturally higher in the morning because of glucose released by the liver, ketones generally rise as the day goes on from a minimal morning reading, I suspect ketone production is lower early because of the glucose present. As the glucose is used ketones should rise. Your experience seems a bit off kilter but given the recent binge will probably resolve quickly. :cowboy_hat_face:


Well, now at 39 hours and BG is at 100 and ketones are back to 1.2. Right direction but still not encouraging. This fast may take a bit longer.

(Michael - Don't expect miracles and you won't be disappointed.) #4

Things sometimes take longer to resolve themselves than you might think. See this:


That’s pretty interesting. It seems that our bodies don’t respond in a linear fashion. While this might seem intuitive, I guess I need reminding. I bet that the rates of change are not constant based on the type, quantity, and timing of the the food. Vino et. al, probably plays a mostly negative role too.

(Michael - Don't expect miracles and you won't be disappointed.) #6

Keep in mind, also, that you consumed ethanol in addition to carbs. The effects of eating just 72 grams of carbs took the better part of a day and a half to go through me. I suspect you consumed way more carbs than that. Depending how much you drank, your liver would proceed to metabolize the ethanol to the exclusion of anything else until completely gone. The combination of food/ethanol slows the metabolism of ethanol. See this:


The concomitant ingestion of various foods with alcohol resulted in a decreased area under the blood alcohol concentration curve, a lower peak concentration and an increased time to reach peak. Michaelis-Menten kinetics indicated a decreased alcohol metabolism rate after the ingestion of carbohydrates or fats.

And this.


I hate being reminded why drinking is a suboptimal idea when trying to lose weight! I suspect you are correct though. I think my actual carb consumption might not have been too much higher than you are speaking of, but the alcohol quantity was definitely in excess. Plus of course, red wine has carbs too…Well the 4th only comes once a year. I’ll live.

(Carl Keller) #8

Consider also that according to FDA standards, blood ketone meters made after 10/31.16 should have:

95% of all measured blood glucose meter values must be within 15% of the true value (a lab measurement); and

So your 102 could be a 117 or it could be an 87. Your goal should be to see it trending downward. Just realize that it may not be as high as your meter says it is.