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Blood sugar low then high after lunch

EngineerMe

Active Member
Messages
25
Location
Cardiff/ Bath/ Kent
Type of diabetes
Type 1
Treatment type
Insulin
Hi all!

So I've been using the Libre for a couple of weeks now which has been making me look more at the peaks and try to get tighter control.

But the past 4 or 5 days I've had some weird trends post-meal
Breakfast is a pretty normal peak then gradual decline all the way to lunch. I do my basal insulin (levemir) at 8am then cycle 20 min to work. But after eating lunch my blood sugar has been going low (at about the 2 hour mark). I eat something to bring it up- e.g. an apple, then it soars up to 12, 13 or even higher by the 4 hour mark.

I don't tend to get rebounds that would take me that high, and the amount I'm eating for the hypo isn't any more than I normally would. I also don't really prebolus so its not that.

Any suggestions? I'm thinking maybe it could be to do with my basal or bolus doses...?
 
How low is low? And what are you having for lunch?
 
What do you eat for lunch?
I have found food with lots of fat like chocolate have a similar effect for me. I believe this is because the fat delays the carbs getting into my blood.
 
EngineerMe said:
But after eating lunch my blood sugar has been going low (at about the 2 hour mark). I eat something to bring it up- e.g. an apple, then it soars up to 12, 13 or even higher by the 4 hour mark.
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Could you not just change your insulin-to-carb ratio to put a stop to the lows, if your unsure if it's a basal issue just do a basal check first @EngineerMe
 
The question is why it goes low. I get why it goes high, because you ate lunch and then ate for a low 2 hrs later. What is it at 6 hours after lunch, still high? You might just be taking too much insulin at lunch.
 
I agree with too much insulin if you have to feed a low. I would require insulin for an apple. Maybe find a less carby food to bring it up slowly without overshooting. Perhaps 1/4 Apple would be enough depending how low you are.

I know one carb raises me about 7(US) so I calculate how much I want to go up and the amount of carbs needed.

I always had that problem when eating carbs or random meals. Keto keeps me much steadier and I enjoy the food more.
The other options are to split the bolus or time the bolus.
 
azure said:
How low is low? And what are you having for lunch?
Click to expand...
Hypo, between 3 and 4
helensaramay said:
What do you eat for lunch?
I have found food with lots of fat like chocolate have a similar effect for me. I believe this is because the fat delays the carbs getting into my blood.
Click to expand...
For lunch I'm eating at the work canteen, so it's unfortunately pretty carby stuff - e.g. lasagne, pie and mash, pasta, meat and potatoes etc.

noblehead said:
Could you not just change your insulin-to-carb ratio to put a stop to the lows, if your unsure if it's a basal issue just do a basal check first @EngineerMe
Click to expand...
TheBigNewt said:
The question is why it goes low. I get why it goes high, because you ate lunch and then ate for a low 2 hrs later. What is it at 6 hours after lunch, still high? You might just be taking too much insulin at lunch.
Click to expand...

Thanks guys, that sounds like the best idea. If I prevent the hypo then I can see if I still end up going high in the afternoon, or if it's just because of the low.
6 hours after lunch it would still be high if I didn't correct to bring it down.

I carb count to work out the bolus dose, but it's sometimes difficult to work out with canteen food that I haven't made myself!
 
I find lasagne needs an extended Bolus on my pump (or split injection on MDI) due to both the lower GI pasta and the fat in it.

Could this be part of the problem? It would also explain the later rise.
 
EngineerMe said:
Thanks guys, that sounds like the best idea. If I prevent the hypo then I can see if I still end up going high in the afternoon, or if it's just because of the low.
6 hours after lunch it would still be high if I didn't correct to bring it down.
Click to expand...

Getting the basal dose right is the foundation to good bg control, so I'd start with a basal test, just eat breakfast (make sure its a low-fat breakfast) and test around 4-5 hours after, if your bg ends up going high in the afternoon then you'll know it's a basal issue rather than your I:C ratio or rebound high.

The following link has some good info on basal testing:

https://mysugr.com/basal-rate-testing/

EngineerMe said:
I carb count to work out the bolus dose, but it's sometimes difficult to work out with canteen food that I haven't made myself!
Click to expand...

That's the trouble and no doubt the portion sizes will vary from day to day, you could download the Carbs & Cals app which might come in handy, but if you don't get the hang of estimating the carb content of the food at work then just take a packed lunch, that way you'll know the carb content of your lunch and can bolus accordingly.

Agree with @azure about high-fat foods such as lasagna, it can cause a delayed bg rise and such meals often require a split-dose bolus.
 
I agree with azure as well. When I was eating carbs or random meals and bolused before them I would often dip then spike. Or spike and not come back down.
It takes about 20 min for humalog to start working so I prebolus but if it's a large meal or heavy animal fat I have tonsplit the bolus to prevent the hypo and the spike. My MDI way of a pump.
 
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