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Question about blood sugar rising instead of falling when I fast

LizH76

LizH76

Newbie
Messages
3
Type of diabetes
Don't have diabetes
Treatment type
Diet only
Hi, I'd really like some advice as I'm completely stumped. I am 50 years old and my last HBA1C was 37, down from 41 a year or so ago since I made diet and life style changes. So I feel pretty good about it, but I've gained weight recenltly which I'm trying to lose, and I've been advised by my PT to extend my overnight fast by a few hours in the morning. However, since I bought a finger pricker a year or so back I have become aware that not eating regularly really makes my blood sugar rise, rather than fall. An example is this morning: I ate at 7.30 this morning and absolutely nothing since then till now (4 hours). I had a decaf black coffee at 10 with stevia and I did a blood sugar test before and after to see if it spiked my blood sugar which it didnt. However the readings went from 5.2 at 10 am (before the coffee), to 4.9 at 10.15 am (after the coffee), but then to 6.2 at 11.35 a.m., i.e. after 4 hours of not eating anything at all. I've done this before and found that my blood sugar was high and rising after an 18 hour fast. Is this normal? I also feel pretty terrible (weak and shakey) so I'm going to go have some lunch! I don't know whether to just rule out fasting as a strategy or to stick with it. Any advice about what is happening would be greatly appreciated! (My blood sugar is also often higher before breakfast than an hour after breakfast...!)
 
LizH76 said:
Hi, I'd really like some advice as I'm completely stumped. I am 50 years old and my last HBA1C was 37, down from 41 a year or so ago since I made diet and life style changes. So I feel pretty good about it, but I've gained weight recenltly which I'm trying to lose, and I've been advised by my PT to extend my overnight fast by a few hours in the morning. However, since I bought a finger pricker a year or so back I have become aware that not eating regularly really makes my blood sugar rise, rather than fall. An example is this morning: I ate at 7.30 this morning and absolutely nothing since then till now (4 hours). I had a decaf black coffee at 10 with stevia and I did a blood sugar test before and after to see if it spiked my blood sugar which it didnt. However the readings went from 5.2 at 10 am (before the coffee), to 4.9 at 10.15 am (after the coffee), but then to 6.2 at 11.35 a.m., i.e. after 4 hours of not eating anything at all. I've done this before and found that my blood sugar was high and rising after an 18 hour fast. Is this normal? I also feel pretty terrible (weak and shakey) so I'm going to go have some lunch! I don't know whether to just rule out fasting as a strategy or to stick with it. Any advice about what is happening would be greatly appreciated! (My blood sugar is also often higher before breakfast than an hour after breakfast...!)
Click to expand...

Hi @LizH76 ,

Welcome to the forum.

What are your BG test numbers when you are “weak and shakey.?”
 
It seemed to peak at 6.2 and about 15 mins later was 4.9. I ran out of the test strips then, and I then ate!
 
Yes. It was wierd because it was 4 hours after eating but higher than 2 hours earlier.
 
LizH76 said:
Hi, I'd really like some advice as I'm completely stumped. I am 50 years old and my last HBA1C was 37, down from 41 a year or so ago since I made diet and life style changes. So I feel pretty good about it, but I've gained weight recenltly which I'm trying to lose, and I've been advised by my PT to extend my overnight fast by a few hours in the morning. However, since I bought a finger pricker a year or so back I have become aware that not eating regularly really makes my blood sugar rise, rather than fall. An example is this morning: I ate at 7.30 this morning and absolutely nothing since then till now (4 hours). I had a decaf black coffee at 10 with stevia and I did a blood sugar test before and after to see if it spiked my blood sugar which it didnt. However the readings went from 5.2 at 10 am (before the coffee), to 4.9 at 10.15 am (after the coffee), but then to 6.2 at 11.35 a.m., i.e. after 4 hours of not eating anything at all. I've done this before and found that my blood sugar was high and rising after an 18 hour fast. Is this normal? I also feel pretty terrible (weak and shakey) so I'm going to go have some lunch! I don't know whether to just rule out fasting as a strategy or to stick with it. Any advice about what is happening would be greatly appreciated! (My blood sugar is also often higher before breakfast than an hour after breakfast...!)
Click to expand...
Those numbers look perfectly normal to me. 6.2 mmol/l is not "high". Am I right in thinking that you have not had a diabetes diagnosis? I'm unsure why you're testing your blood.

Blood glucose levels will naturally vary across the day in response to many things, not only food. Your liver will adjust levels according to what it thinks you need at the moment - and not eating is often one of those. Most people find that things such as stress, illness, ambient temperature, or exercise are also reflected in BG ups and downs.

You also need to be aware that fingerprick readings have an allowable error of 15% or so. In practice this means that a given true blood glucose value of (eg) 6.0mmol/l might return a fingerprick result anywhere or somewhere in the range 5.1 to 6.9 and still be acceptably accurate. You can, for example, take two separate readings using the same drop of blood and the machine will return different values.

So I'd guess that's what happening is that when you fast, your liver is creating glucose from body stores to keep you fuelled. If you're fasting to lose weight, this would be what you want to happen, as some of that stored energy is stored as body fat. Many people who fast report that it takes a bit of time to adjust to it, sometimes feel a bit weak and shaky in the early days, and that wouldn't be unusual.
 
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