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Fasting and Rising BG

Element137

Well-Known Member
Messages
128
Type of diabetes
Type 2
I have been experimenting recently with intermittent fasting, aiming for 18-24 hour fasts to begin with, but I am seeing my BG level rise post fast ?, and I wondering what other people's experience has been when first starting to use IF as a tool. My levels are generally good, over the last year ( according to my meter ) my averages levels have been :
AM Fasted = 6.0
Pre Meal = 5.4
Post Meal (2 hours) =5.8
All done with 20-30g of carbs per day as a general rule.
My Hba1c is roughly aligned with these averages so I am pretty confident in the data. Yesterday, fasted from Sunday evening(6PM) to Monday evening (6PM). My BG at 6.00 PM post fast was 5.5 ( not as low as I would have hoped after 24 hr fast ) and post meal was 6.3 ( usual low carb evening meal ) - wake up this morning, fasting BG = 6.8, one of the highest FBG's I have had in the last year - now I know its a small sample, only done it a handful of times, but with similar results - and I will have to repeat a number of times yet to see any significant pattern, but has anyone else experienced this ?- I did some reading last week on low carb induced physiological insulin resistance and was wondering if that is what I am seeing ? , if so, anyone experienced how to break it ?
 
I don't think meters are as accurate as we would expect them to be, so that 6.8 reading could have been lower. Also, all sorts of factors affect our levels - the weather, stress, a virus. Maybe fasting triggers the liver to release glucose at a higher rate than you would get from eating a low carb meal. I think that's why I get temporarily higher readings in the morning - my liver dumps a bit more than I need, and then I have to walk it off.
My own personal opinion is that it's easy to get too caught up in all the statistics, but there are millions of chemical reactions taking place in our bodies and we aren't perfectly tuned machines. It looks to me like you are doing very well with your diabetes control so why not find a new interest instead?
 
This is my interest , don't get me wrong, I am not in anyway concerned about my levels, far from it, very happy with my level of control, this is about curiosity and gaining deeper understanding - and I have found the most useful insights are from people doing the same thing, with all the same real world variables in play, hence my request for other peoples experience, thanks for yours.
 
Ah yes, I'm sorry, I see where you're coming from now - disregard the last bit of my message! Did you feel that your glucose was low at the end of your fast, possibly prompting a liver dump? I think my liver over does it a bit when this happens, prompting higher readings.
 
I felt entirely normal - fasting is not hard to do, especially when just continuing from a nights sleep into the day - for me anyway - what's got me curious is I am seeing increased BG rather than reduced BG via fasting - I am trying to understand from other peoples experience of doing IF if there is an adaptation period, or, due to a year of low carb I am actually seeing a different type of insulin resistance ? - the results are at odds with what I expected - hence - got me curious.
 

Physiological Insulin Resistance can happen after a period of time on a very low carb or ketogenic diet. It happens when your body detects that available glucose is low. It then sends messages to all the cells to reject this glucose in order to spare it for the brain. Those are the mechanics and I can understand how this happens.

From everything I have read, it sends up fasting and pre-meal levels (your normal basal level) I have no idea how this happens as the science goes over my head.

Apparently, if you increase your carb consumption for a few days, it goes away and you can then resume a low carb diet.

http://ketopia.com/physiological-insulin-resistance/
 
Thanks for that - fascinating stuff - I have wondered for some time now whether to experiment with introducing more carbs and measuring the results - just never want to give up the gains I have made - the link at the bottom of the page
http://www.diabetes-warrior.net/201...-may-rest-now-glucose-tolerance-test-results/
is a fascinating (home) study of OGTT testing direct from low carb, and then from a short ( 3 day moderate carb intake 150gs) - I am considering whether I would be brave enough to try it .
 

That link is indeed interesting.

I myself am considering doing a home GTT using Lucozade. I happen to have an old bottle of the original full sugar stuff in a cupboard as a left over from times past. My concern is the carbing up for a few days beforehand and whether that may have long term effects. I know it is essential if you want a true result. The test itself doesn't bother me. I actually like Lucozade and it is only 2 hours out of a morning after fasting overnight.
 
If you are brave enough to do it - be fascinated to see the results ? - I cant help feeling its a bad thing to do ( short term ) - but I really have become conditioned to eating to my meter- and its proved to be an immensely powerful motivator - I am very wary of trying this - however - I do feel like egging you on........, go on, you first......
 

LOL. When I do the carbing up I think I will put my meter away in a locked drawer! I also eat to my meter, which is also a powerful motivator for me along with my detailed data sheets. I would not like to see my lovely averages and graphs disintegrate. I go away mid August and am thinking this may be a good time to do it. Extra carbs on holiday with no guilt and no meter readings may be a pleasant treat, (thinking ice cream and real toast here) plus we do tend to do a lot more walking on holiday, which may help.

No ............ you first
 
I also have rising BG whenever I fast.
It's a lot worse if I don't drink enough water while fasting.
I think there is a lot of benefit to fasting, but I wonder if that benefit is eradicated by the higher sugar levels.
I am relatively at the beginning of a LCHF wol, and I have asked myself if the rising BG when fasting is something that would get better after I have been doing it for awhile, or after I manage to lose a lot more weight.
I'd really like to know, as well.
 
This is how I started smoking at the tender age 12...LOL - (another addiction I have got rid of). I am starting to think that a challenge to the system once in a while though may prove to be beneficial, problem is it feels wrong. I am going to continue experimenting with Intermittent Fasting just to see if the results remain consistent, albeit not what I was hoping to see - will keep posting the results. I always face the same dilemma with my meter if I am going to eat off plan, part of me wants to see the result, every opportunity to learn about how my body reacts is valuable, part of me not want to look at the meter result .
 
Have a look at this link - explains how prolonged Low Carb can raise Fasting BG
http://high-fat-nutrition.blogspot.com/2007/10/physiological-insulin-resistance.html

 
I have found that with a days fast, dong a 20 mile walk stopped BG increasing. Resistance training at the gym may be a lot more effective, as more parts of the body will be burning up BG while they recover. (As by BG no longer increases when I skip two meals, I can't test this out.)

FrancebrunNY said:
I also have rising BG whenever I fast.
It's a lot worse if I don't drink enough water while fasting.
Click to expand...

So drink a lot more water and have a little salt.

I think water is needed to burn fat, so you may be seeing the liver damping out its glycogen store, once the liver has less glycogen in it, then it will become more sensitive to insulin, and hence should give better BG control after the fast, Provided you are controlling your carb intake at all times.

I think (unless on a strict LCHT) it takes over 2 days for the body to adjust to fasting and start burning fat. So a short fast for most people will "just" help to empty the liver of glycogen and maybe remove a little fat from the liver. However emptying the liver of excess glycogen can then enable our body to burn more fat even when we are not fasting provided we have long times each day with a low insulin level.

Bluetit1802 said:
My concern is the carbing up for a few days beforehand and whether that may have long term effects.
Click to expand...

It may take 3 weeks for your body to once again become happy to live on fat once you go back to low carb.
 
Beat you! - I was 11 and started smoking when me and a fried bunked a domestic science lesson - I then smoked like a trooper until diabetes diagnosis when I finally gave up and stayed given up
Wrt fasting - I find the way I fast makes a difference - 24+ hour fasts always produce an initial drop in sugars followed by steadily rising bounce back to silly levels, even if Im eating nothing Under 16 hr fasts or fastining mimicking ( low cal and low carb) sees the drop too but not the bounce back rise
 
I have had a bit more of a serious attempt at this over the last three weeks - trying to get a bigger sample size - been fasting min 20 hours, three days per week (Mon, Wed, Thu) - so from 8.00PM on Sunday night to 6.00PM Monday for example - without fail every fasted day I see Increased levels both first test in the morning, and before eating at 6.00PM ( effectively at the end of the fasting period ) I cannot make sense of it - I would have expected to see lower levels - yet always they are higher than my typical levels - also struggling to see any meaningful explanation anywhere regarding what mechanism is at play ? - anyone experienced this ? - is this just a case moving glucose out of the liver ?- a good thing ? which will eventually stop ? - I presume my liver is intervening/dumping to stop going too low and maybe overshooting ?- at this point I am questioning whether to continue with it as it means higher levels for three days of the week, the very opposite of what I was trying to achieve - Very confused.
 
Hi @Element137 - interested to read your latest experiment, because I found exactly the same response. I did daily fasts recently for 10 days straight, 1st-10th October, eating only evening meal, though I continued with tea/coffee/water as normal. My BS levels were raised at every test, sometimes by as much as 2mmol/L. Previously my rise had been around 0.5-0.8mmol/L. This was totally the opposite of what I was trying to achieve, and I stopped the fasts, and returned to my two meals a day from 11th October onwards. What I find even worse - is that my numbers have remained higher, still in the 6s, whereas previously I had always been in the low-medium 5s. My meals were no different from those I usually eat - it's very disconcerting when you haven't a clue why things have gone awry.
 

I suspect (and I only suspect) that it is insulin resistance causing your problems. You can't stop your liver dumping glucose if it is triggered to do so by low levels. It is what our livers do, and it keeps us alive in times of fasting and between meals/overnight. In normal healthy people this still happens, but the pancreas jumps in and secretes insulin to balance out the livers's efforts, keeping glucose levels stable, and at the same time tells the liver to stop dumping. This system is regulated by hormones (glycogen, cortisol and human growth hormones.)

In diabetics, this well regulated system breaks down. The liver and other cells are insulin resistant, so when the liver dumps from its stores, the insulin secreted by the pancreas can't do its job. The end result is the dumped glucose takes much longer to clear and the liver will keep dumping.
There could also be other factors such as a worn out pancreas that doesn't produce enough insulin, or even wonky hormones.

Does that help?
 
If I fast my numbers go up - I find that if I eat two meals a day well spaced out, with a few carbs with the first and the rest later I get low numbers - last time I checked I got 6 mmol/l just before two hours after eating - I was going out so I was a bit early but wondered if I could eat dessert before I went.
 
The same thing happens to me when I fast. BG drops slowly throughout the day and then starts to rise a little in the evening even though I haven't eaten. ? Baffles me too ?
 
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