2 hour postprandial readings:- 2 hours from start or finish of meal????

lindisfel

Expert
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5,659
Hi all, Let's look at this logically. The datum has to be from first bite! We all eat at different speeds and we masticate differently as well as digest differently with different guts and health issues. The only thing that isnt variable is the first bite datum. regards D.
 

Mr_Pot

Well-Known Member
Messages
4,573
Type of diabetes
Type 2
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Diet only
Hi all, Let's look at this logically. The datum has to be from first bite! We all eat at different speeds and we masticate differently as well as digest differently with different guts and health issues. The only thing that isnt variable is the first bite datum. regards D.
We all have a last bite as well, so that could equally be the datum. I would try taking my BG every 15 minutes during a long meal except I eat very quickly and I am not sure my fingers are up to it. Maybe someone with CGM could provide some data. As others have said, the important thing is to be consistent with your timings. I measure 90 mins after last bite which @azure does not allow me to call post-prandial but seems to me to be a good measure of the effect of a meal. Note that I am type 2 on no medication, those who are type 1, type 2 on insulin or have RH no doubt have other requirements and regimes of testing.
 

Bluetit1802

Legend
Messages
25,216
Type of diabetes
Type 2 (in remission!)
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Diet only
We all have a last bite as well, so that could equally be the datum. I would try taking my BG every 15 minutes during a long meal except I eat very quickly and I am not sure my fingers are up to it. Maybe someone with CGM could provide some data. As others have said, the important thing is to be consistent with your timings. I measure 90 mins after last bite which @azure does not allow me to call post-prandial but seems to me to be a good measure of the effect of a meal. Note that I am type 2 on no medication, those who are type 1, type 2 on insulin or have RH no doubt have other requirements and regimes of testing.

I would say 90 minutes after last bite would give you a fair indication. Last bite wouldn't work for me because I have a mug of tea after I finish eating. From my Libre sensor I peak between 60 minutes and 90 minutes after first bite depending on what combination of foods I've eaten. I rise steadily from about 10 minutes after I start.
 

lindisfel

Expert
Messages
5,659
We all have a last bite as well, so that could equally be the datum. I would try taking my BG every 15 minutes during a long meal except I eat very quickly and I am not sure my fingers are up to it. Maybe someone with CGM could provide some data. As others have said, the important thing is to be consistent with your timings. I measure 90 mins after last bite which @azure does not allow me to call post-prandial but seems to me to be a good measure of the effect of a meal. Note that I am type 2 on no medication, those who are type 1, type 2 on insulin or have RH no doubt have other requirements and regimes of testing.

We all have a last bite as well, so that could equally be the datum. I would try taking my BG every 15 minutes during a long meal except I eat very quickly and I am not sure my fingers are up to it. Maybe someone with CGM could provide some data. As others have said, the important thing is to be consistent with your timings. I measure 90 mins after last bite which @azure does not allow me to call post-prandial but seems to me to be a good measure of the effect of a meal. Note that I am type 2 on no medication, those who are type 1, type 2 on insulin or have RH no doubt have other requirements and regimes of testing.
We don't have to live by logic Mr Pot! Do whatever ticks all your boxes! I'll do what old blue eyes sang....I'll do it my way! :)
 
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geemacwilly

Member
Messages
18
Type of diabetes
Type 2
Treatment type
Tablets (oral)
Saw the diabetic consultant on Tuesday and she said it doesn’t matter if its 2 hours after starting or finishing a meal as long as you are consistent.
 

rosieP

Newbie
Messages
2
Type of diabetes
Other
Treatment type
Diet only
This video has the most helpful explanation of gluose challenge testing I've found so far:

Great video. I am a doctor but still learning!!
My HbA1C is creeping up despite all my efforts. I will definitely try to find the spike. Fasting BG always around 6.3 preprandial below 6 but post...all over the place. Here goes!
 

Bluetit1802

Legend
Messages
25,216
Type of diabetes
Type 2 (in remission!)
Treatment type
Diet only
Great video. I am a doctor but still learning!!
My HbA1C is creeping up despite all my efforts. I will definitely try to find the spike. Fasting BG always around 6.3 preprandial below 6 but post...all over the place. Here goes!

Welcome to the forum! There are many, many things to learn about how best to manage diabetes on this forum. Have a good read round, and join in. :)
 

LittleGreyCat

Well-Known Member
Messages
4,233
Type of diabetes
Type 2
Treatment type
Tablets (oral)
Dislikes
Diet drinks - the artificial sweeteners taste vile.
Having to forswear foods I have loved all my life.
Trying to find low carb meals when eating out.
I think that testing 2 hours after first bite is probably the most repeatable and consistent.
The last bite is very much a variable - especially if you get distracted during the meal.

Nothing is absolutely accurate - you could eat exactly the same meal by scoffing it in two minutes or picking at it for two hours and get completely different glucose test results.

I think we are trying to measure effective insulin response and as far as I know the insulin secretion is triggered by the first bite of food.

Granted that if you graze on LCHF food for an hour or so then lay into an apple crumble with caramelised brown sugar on top at the two hour point you may not capture the spike by either method!

As others have said, first test at frequent intervals (probably best measured from first bite for consistency) and work out when your BG tends to spike. Then structure your testing to measure the spike and how long it takes for your BG to recover.

Slow acting foods can be interesting (or so I read); for example the fat in pizza can delay the response to the carbohydrate in the base so the spike can be after the two hour point.