Blood glucose while fasting

(Utility Muffin Research Kitchen) #1

After going OMAD for a few months I switched to 48h fasts recently (usually twice a week, say Sun evening to Tue evening and Wed evening to Fri evening). I was a bit surprised that my blood glucose pattern were changed, after registering an 80 yesterday morning (second day of the fast) instead of my usual ~105 (dawn effect, insulin resistant) my bg went up to 100 in the afternoon. No physical activity which would cause a spike.

Any insight what the expected behavious is for bg during a 2-day fast? Fung says elevated glucose levels are due to the liver releasing stored glucose, but I wonder where that should come from with a keto diet. As for gluconeogenesis, that should in theory only produce glucose when it’s needed and not for storage, or am I wrong there?

(bulkbiker) #2

Not sure how good your meter is but 2 readings of 90 would be within the margin of error for most meters… so it could just be that.

Blood glucose is extremely dynamic influenced by all sorts fo things… time of day, stress, even walking slowly or briskly… not sure a 20 mg/dl change is anything significant.

Haven’t done any fasting for a while but last time I did an extended I saw pretty much the same levels that you are. My lowest BG reading was usually on the third day in the afternoon then going back up after that.

(Utility Muffin Research Kitchen) #3

The fact that my fasting glucose was very reliably between 100 and 105 indicates that the meter may be off, but at least it gives consistent results :slight_smile:
So there appears to be a real change of +20, give or take a bit. Yes, it’s not much, and I’m certainly not worried, but I’d like to know why this happens.

(bulkbiker) #4

Complete guess … your body wasn’t happy at 80 so your liver pushed your blood sugar up… homeostasis wins again…?

(Utility Muffin Research Kitchen) #5

This answer reminds me of an old joke that was making the rounds when I was a student :slight_smile:

2 people fly a balloon and get lost. They find someone on the ground and ask him “Where are we?” He answers “in a balloon!”. One guy in the balloon turns to the other and says “That was a mathematician”. Asks the other “how do you know it was a mathematician?” Answer: “Well, his answer was 100% correct and 100% useless”.