Fasting Glucose Went Way Low

fasting

#1

I am on Day 5 of a fast (water, seltzer, tea, HWC and coffee) that I planned to end today at dinner. Starting on Day 3 in the afternoon I would get nasuea in the later afternoon. Took some electrolytes and it went away. Same thing on Day 4. I have 50 lbs to lose to be at a 25 BMI and that is the very least and that assumes I am big boned which I am not. So I have over 1500 calories of fat available.

No health conditions except hashimotos which I take synthroid, Keto for over a year. Fasted often for 5 days but not recently. This never happened to me except during my first month on keto. I did not get the flu, I got nausea whether I ate or not. It went away.

This morning was slightly nauseous again and was planning to take my blood sugar when I got up, I like to do this on the last day, no real reason. My BG which I take about once a month is normally between 80-90 on keto. This morning is 43! I have never seen that. I have no idea what my ketones are, the cheap breathalyzer that I use barely works on me. It was showing 0 after 3 days. Yesterday it showed .3 which is what it showed when I checked this afternoon.

I know the normal numbers do not apply to fasting if you are not on medication but this combined with the nasuea makes me wonder. It went away as I started my day. I took some psyllium in water which I take on the last day of the fast anyway, although usually a little later in the day. I managed to do what I had to do and not eat. Went shopping at a big box store (lesson learned never go food shopping on Day 5 of a fast, my bill was easily twice what it usually is). I feel ok, not amazing, A little foggy but not terrible. Is this a sign of hypoglycemia or simply a coincidence that my BG is low along with nausea


(Todd Allen) #2

I’ve had readings in the 30s without any adverse effects, though glucose monitors aren’t super accurate to start with and their accuracy falls off outside of the range they are designed for, typically 70-140 mg/dl. When I get an unexpected result I’ll retest and take care to follow guidelines rigorously, wash and carefully dry hands, etc. as even a little moisture/sweat/dirt can have a big impact. I have Raynaud’s and it is more pronounced when I fast. When it flares I have a harder time getting a sufficient blood drop and when I force it with a lot of squeezing I tend to get a lower result than if I soak my hand in warm water for a few minutes and have good circulation. I’m guessing very slow moving blood may get more sugar depleted or maybe it has something to do with just getting a barely sufficient sized drop of blood.

If ketones are high the brain doesn’t require glucose levels as high as typical although I’ve never seen a chart quantifying the effect. Mature red blood cells are glucose dependent but their metabolism is minimal and we typically have an over abundance and fast regeneration when needed so I’d expect rbc’s are even less of a concern than the brain with respect to hypoglycemia.

Hypoglycemia is a major threat to diabetics whose glucose regulation is poor and can be hugely impacted by medication dosing. But for healthy people not monitoring their blood glucose the only way to know one is hypoglycemic is through symptoms such as dizziness, racing pulse, blurred vision, brain fog, etc. If you aren’t experiencing significant symptoms I wouldn’t worry much over a low glucose monitor reading even if you are pretty sure it is accurate. If you get symptoms and especially in combination with low readings then I would break the fast.


#3

Thank you.

The nausea I have been getting is pretty not typical for me. I waited until an early dinner but was a little foggy.

What scares me is that I had nausea and the low reading at the same time. It is the same monitor I always use. About an hour ago I had a 62. I was a little foggy, definitely cranky although not hungry.

I have since lightly broken the fast and while I am still tired, I am in a much better mood overall


#4

So long as you’re not diabetic, don’t fret over fasting BG. Your body will produce as much insulin as it needs. It is not constant, it varies throughout the day and is also impacted by activity level, stress, and hormonal fluctuations (ie. menstrual cycle, testosterone).


#5

Thank you but I am not really concerned about insulin, I am wondering why I got nausea on this fast? And whether the 43 was random or whether it was the reason for the nasea

I ate last night as planned and feel great today except for a weird backache. Feel so much better today otherwise. The backache started around 4pm yesterday when I started the psyllium to break the fast but had not really eaten. I got some stiffness in my lower back (happened to me once before on a fast but did not progress and I thought it was strange then too) this time I woke up today and my lower back is completely out. Could not bend down to pick up clothing. Was dropping something off and had to ask a neighbor to release my trunk latch as I could not bend down. This happened to me on a few occasions while on Sad but I usually thought it was gluten intolerance (I have Hashimotos and a child with Celiac but I do not have it). I find it so bizarre that this would happen at the end of a fast.

The only things I have eaten during the fast were HWC (used a different brand than usual in the last 48 hours), coffee, tea, seltzer, whatever is in my supplements (they say no gluten and fillers usually but I have not checked each one), my synthroid and some psyllium to break the fast (same jar I have been using for the last month without a probelm). IAnyone have an explanation? Inflammation without eating? No new stress. Makes me wonder if I have a dairy intolerance although I eat tons all the time without a problem. I cannot remember the last time I had a back problem, if anything minor aches and pains have been going away faster over the last year.

On prior fast on Day 3 or 4 if I bent down to quickly I would see spots but felt great otherwise. On this one I did not have a spot problem but I definitely did not feel great on Day 4 or 5 but feel really good today except for the backache


(Todd Allen) #6

Some medications for diabetics to lower blood glucose will continue to do so in a fasted state which is what I was experimenting with to get very low blood glucose when my ketones were very high but I don’t think you’ve said anything about being diabetic so that probably isn’t a factor in your case.

I’ve read that as blood glucose falls into the 60s mg/dl growth hormone, norepinephrine and adrenalin should be kicking in to stimulate the liver to dump glycogen and kickstart a little gluconeogenesis as glycogen depletes which it will when fasting. If blood glucose falls into the 50s cortisol should crank up and turn on gluconeogenesis full bore in the liver and kidneys. Blood glucose going lower might indicate something like cortisol insufficiency/adrenal fatigue or maybe something with your liver and/or kidneys impacting peak gluconeogenesis or maybe excess glucose demand such as if the muscles haven’t shifted sufficiently from glucose and ketones to fatty acids - though that shouldn’t be an issue for someone long term keto who is solidly fat adapted. I’m guessing that your ketones also came down somewhat from typical fasting highs to produce the symptoms you experienced with your blood sugar in the 40s.


#7

Thank you. This is what I was wondering about. Maybe I am not fat adapted? I lost 35 lbs between March and September and have at least that to lose still. Completely stalled by December, no loss of inches since then.

I am not on any medication other than synthroid. My BG in the morning is generally between 80-90 but it has been 96 on occasion. Both my parents are diet controlled T2Ds. I rarely check it.

When I got the breathalyzer in June it would show .4 - .8 and now even on Day 5 it barely showed anything but then it was $10! I may go back to ketostix. Not spending for blood.

What makes me really wonder is even though I have only cheated 3 times in a year, I do overindulge in the 4 Horsemen of keto, berries (and sometimes very small pieces of other fruits), nuts, peanut butter and cheese. I only use swerve a couple of times a month. Given my family history I may be more IR than I realize (not in a position to get a fasting insulin test, live in a non self testing state) which means that even berries and macadamia nuts will prevent fat adaption? Personally I think the fact that I have not cheated is a sign that I probably am fat adapted. I did read Amy Berger’s essay on it. I would say I am good except that I do not always have the mental clarity. This last fast really makes me question it. It was as if I hit a wall late on Day 3 or early on Day 4. Note on Day 3 I was more active than usual, I cleaned out my porch which involved taking a lot of kids toys they have outgrown to the trash

My back is mostly better this evening which has to be a record for recovery but usually gets worse in the morning so will see


(Todd Allen) #8

It sounds like you are fully fat adapted. 35 lbs in 6 months is a great rate of fat loss and I think stalling without a major rebound is a good sign too. On most any diet people can lose for 6 months or so but most rebound after that. Sustaining the weight loss suggests you are on track with keto. When I was in my early fast weight loss phase I also had a much easier time reaching much higher ketone readings on my breathalyzers. It’s actually a good sign of fat adaptation when the readings come down suggesting that the muscles have switched from ketones to fatty acids such that one isn’t using nearly as much ketones.

Which does make it a bit of a puzzle as to why your blood sugar began to crash. But seeing as it didn’t start happening until you were deep into your fast and after higher activity my thought would be that if/when you try fasting again you might supplement with a little fat, especially coconut oil or MCT oil which should boost ketones and see if that helps.


#9

Thank you! I am so happy you said you think I am fat adapted! Was really starting to worry that eating too many nuts and berries had ruined my fat adaption. I definitely have at least 50 lbs of fat if not more so that is a little bizarre. I will try maybe adding butter next time although I think the next long fast I want to try without the HWC to see if I have a reaction to dairy. My backache is almost completely gone but it was bizarre that it would happen at the end of a fast like that