how much should blood glucose levels vary?

If you can limit your glucose rise to 2mmol around 2hrs after eating then you're doing amazingly well. (Tell us how you do it).

Don't get worried about individual readings or even 1 day's readings unless they are massively off from what you expect. Meters are not the most accurate devices, they have a variance of up to 15% either way and there are many variables with finger prick tests anyway, so look for trends and repeatability.

We mostly all would agree with testing. The whole anxiety argument is one I’ve gotten from my gp but I’m more anxious not knowing what’s going on. It’s fundamentally about cost and various excuses used to avoid admitting that.

Test on getting up. That may be higher than you hope due to dawn phenomenon. (You liver “helping” you get up with a morning shot of glucose. Otherwise test before eating and 2 hrs after. (Some people also test at 3hrs in case of slow digestion or slow rise). That should give you a better idea of which foods work for you and which don’t. You’re looking for no more than 2mmol rise between them. I tend to get lower readings as the day goes on.

Dehydration, stress, illness, lack of sleep, medications can all affect the readings too. As can food combinations. Eg eating fat with a carb helps slow down the rise.

Which foods to choose? Well you may or may not get the standard balanced diet/ eatwell plate / eat starchy carbs rubbish from your appointment. We as diabetics struggle with carbs. Therefore, to me at least, it makes a huge amount of sense not to eat many of them. Read labels for carbs not just sugar. Dietdoctor.com and ditchthecarbs.com both helped me a lot with food ideas. There are lots of others too. How far to take it depends how much change you’re willing/able to make.

randomwoman said:

Thanks, this is helpful. I'm guessing from your first sentence that "massively off" means something outside the standard NICE-defined levels then?

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If something raises me by 3, 5 or even 10 mmol I wouldn’t eat it again! Make sure your finger was clean though and take note of other factors eg stress sleep depravation, illness etc

randomwoman said:

Just to clarify (sorry I'm new to all this), we're talking in whole numbers here right? 3.0 rather than 0.3?

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Yes whole numbers. So if i went from 5.2mmol to 6.4mmol after 2 hrs I’d be ok with that. If I went up to 8.7 I wouldn’t repeat the food/meal as is. If I went to 10.1 I’d avoid it like the plague.

randomwoman said:

Thanks, this is helpful. I'm guessing from your first sentence that "massively off" means something outside the standard NICE-defined levels then?

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As a T1 my situation is quite different to yours but every now and then I get a blip. I go through the motions of glucose checking, expecting the result to come in at say 8.5ish and it will be 12 or something and I'll have no idea why.

But I wouldn't worry about this kinda stuff just yet!

randomwoman said:

Thanks, that's hugely reassuring given where my readings have been.

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Just remember its the amount of rise from before eating to after - not the specific numbers - for food testing.

And ideally the overall trend of the actual number to be heading downwards. There will always be blips as said above. When I started before meals were often 6’s, 7’s or sometime 8’s. Now they’re usually 5’s and 6’s and even a few 4’s this week.