2 Hours After Meal Spike

Hi everyone I’ve been a T1D for 26 years and pumping for 19,

So to start I’ve been on the 670G loop system for 3 weeks now and my educator and Endo are out of ideas as to why my blood sugar spikes to 250 2 hours after every meal. I take my carb correction/bolus 30 minutes before my meal and everything seems fine but then 2 hours after I have eaten my blood sugar rises very rapidly to 250.

Has anyone else experienced this and what did you find that helped? I have already reduced my carb ratio as low as my Endo feels comfortable doing (going to 13 to 10 in the mornings/afternoons and then from 11 to 9 in the evenings). And all my educator keeps telling me is to bolus at least 15 minutes before my meals even though I keep telling her I am bolusing 30 minutes before meals. Any and all help would be greatly appreciated.

You control the two most influential factors in this scenario: dose size and timing.

Your optimal insulin to carb ratio (I:C) is more about what your body says works and not so much about your doctor’s comfort level. When you do spike at two hours post-meal, does your BG level return to pre-meal levels at the four or five hour mark without any added insulin corrections?

If it remains elevated, then you need to make your I:C more aggressive. It it returns too low at 4-5 hpurs post-meal, then your I:C needs to be made less agressive. Try eating the same meal several times so that you can optimize the best dose size for that meal. A kitchen scale can help you to accurately quantify your actual carb consumption.

If your BG returns to pre-meal BG levels then that suggests that your insulin dose is correct but your timing is off. Stephen Ponder, author of Sugar Surfing, counsels readers to watch for a characteristic downward bend following a meal insulin dose before they start to eat. He calls this “waiting for the bend.”

Living with a fixed pre-bolus time, like 15 minutes, does not allow your body to signal when it’s best to begin eating. I’ve found that my optimal pre-bolus time is indicated by the characteristic downward deflection on my CGM trace. Sometimes its 15 minutes but can take as long as 60 minutes. Your ideal pre-bolus time can change from meal to meal and from day to day.

Diabetes is not a static disease, it’s dynamic like a lot of physiological things. Static formulas are just a starting point. You need to modify them by doing experiments and letting your body tell you what is needed.


It is possible your carb ratios or sensitivity are not working for the 670G as they were with your former pump. I suggest talking to your educators about the lowering your sensitivity or / and increasing carb ratios.

I had to do both to get my 670 on track.

Note: I am a Medtronic ambassador. My opinions are my own. They did not pay me to say nice things about Medtronic devices or the company. OK, they sent me a shirt and a cup but even I am more expensive than that.


Do an extended bolus or square wave bolus or whatever Medtronic calls it.

If your BG is good for a while after you eat and then spikes later, you need a little more insulin later.

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While in auto mode/closed loop I cannot alter how a bolus is given. There is no way to do a square or duel wave bolus. Thank you though.

Excellent disclosure. Do I sense guilt? LOL
Too bad, there’s not much competition to medtronic.
Animas? Another one bites the dust.
Tandem, please hang in there.

Tandem is looking amazing from a financial perspective so far this year.
Market Cap is up over 15 times in the last two months.
Tandem has their Q1 conference call coming up next week on Thursday if anybody is interested. Often times lots of interesting bits of information particularly at the end of the financials when they hit the Q &A portion.

I know I am certainly looking forward to the approval and release of the Tandem t:slim X2 Basal-IQ (PLGS) update which is expected this Summer.

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How can you guys discuss a BG spike at 2 hours and not even ask about the food and amounts in the meal.

Yeah we are all different.

And all respond differently to insulin.

BUT the greatest variable of all is the food we eat.

For example I enjoy a beef stew. All the carb is from vegetables except when I also have a small dinner roll or biscuit. 6 or 8 hours after the meal my BG will start to rise and continue to rise slowly for 2 or 3 more hours. A great healthy meal but hard to deal with from the front end.

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Because changing the insulin amount and timing of delivery is a better fix than changing what or how much you eat.

I don’t change my choice of food, I change my choice of insulin amount and timing of delivery.

Otherwise people are limited in what they eat. And I don’t like to be limited.

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You are implying that you spike regardless what you eat.

Is that true?

I am suggesting that what and how much you eat may be part of the issue.

Sorry for sugesting the obvious.

No, I am not implying that I spike.

The original poster said they rise after 2 hours. So I suggested they do an extended bolus to prevent that rise.

You asked this :arrow_down:

And the reason I didn’t ask about the food is because is doesn’t matter to me if it is cornbread or pizza or potatoes. If they are spiking 2 hours later, they should consider trying an extended bolus.

If the food is causing the spike 2 hours later, why do I have to know the food type before I suggest an extended bolus?

Anyway, that’s why I didn’t get into questions about the food type.


This is so frustrating, I know!! Another real consideration (since you’ve been T1 for so long) is that you may be experiencing delayed digestion due to gastroparesis. Do you use a CGM? If so, experiment with the timing of your bolus. Instead of pre-bolusing, bolus when you start the meal or as soon as you see the graph trending up. Best to experiment with low fat meals so that you don’t add that complication into the equation. Extended boluses could help in this scenario too but will require extensive trial and error.

Maybe too many carbs at meal times?, or the timing of your bolus? you should be able to change and lower your carb ratio too and where is your insulin sensitivity setting set at? also is your bg in range before your meals? are you counting your carbs accurately? are you eating high fat and not accounting for that? i would also think your Endo should be able to figure it out, or maybe a second opinion from a different Endo?

I agree, many of my post meal spikes are simply due to timing of the insulin. I try to wait at least 15 minutes but there have been times, that I wait 45 until I see that “bend” on my CGM.
And even with pizza, using my extended bolus, I can handle most of that later post meal(extra cheese!) rise.
Over the years, I have come to realize all those times when I said I don’t understand where that number came from, I can now with all the knowledge and education I have gotten from my medical team, clinical trials and all of my friends on line, most of those outliers are very explainable. Just a little analysis and most times, I can find the answer.
This one seems to be all about timing. And I think trying Terry’s suggestions could bring the timing issue into line. Good luck and remember everyday is an experiment. The key is to learn from those experiments.

Okay, about me, T1 for almost 40 years, Tandem and Dexcom. I have found in the last month or so that the insulin kicks in before the food starts to have an impact. My meal bolus will cause me to tank (major low) and then in about 1-2 hours the food starts to kick in, the insulin peak is over and my bg skyrockets. Thanks to John Walsh and Gary Scheiner’s books, I am dealing with meals like someone with gastropariesis would. I give the meal bolus when I start to eat (or up to 15 minutes after first bite) and use the extended bolus for just about every meal.

In anticipation of questions on what foods are involved, I eat very low carb (the carbs are from vegetables) and minimal calorie as well. It is frustrating that the Endo I have to use (health plan, ya know?) insists that bolusing 15 minutes before eating will solve the problem. That is counter-intuitive (like everything T1D!) to me.

Admittedly I am very aggressive in my D mgt, and having the patience for the correction bolus - that is required to cover the food that kicked in so late - is really difficult for me. It takes strength of will not to keep dosing and ending up stacking.

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Tim35Parent of a Type 13d
Tandem, please hang in there.

“I know I am certainly looking forward to the approval and release of the Tandem t:slim X2 Basal-IQ (PLGS) update which is expected this Summer.”

What are the chances of the PLGS actuallt being released this summer. When I first got the Animas in 2009, one of the reasons for doing so was the belief that the Dexcom integration would soon be available. Hah. So how good are the announcements from Tandem?

Don’t know how to quote from previous comment.

With your mouse, highlight the portion of text from the other person’s comment then hit the “Reply” button on that other person’s comment.

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It is true that nothing is guaranteed until it happens. One of the things I look for is consistency in public statements from a company. Results of related clinical trials are also helpful to show real progress. Misleading consumers is a fact of life and happens every day. However misleading investors is a US Federal Crime which routinely results in convictions.

I pay no attention to what a salesperson might say about future products.

I consider what the CEO tells investors about the status of upcoming product releases to be fairly reliable.

= = = = = =

March 1, 2018
Tandem CEO, Kim Blickenstaff

In 2018, we expect to build on our commercial momentum while advancing our robust product pipeline. To that end, we recently submitted a PMA application to the FDA for the t:slim X2 Pump with Basal-IQ technology, a predictive low glucose suspend feature, and we’re preparing for a U.S. launch this summer to existing and new t:slim X2 Pump customers, pending FDA approval.


Just practicing, thanks.

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You should sense absolutely no guilt. I am proud to do it. I do the disclosure as a matter of course when I comment on anything about Medtornic. I also hope Tandem holds on. We need choice.

I suggest you examine my record on this board before you make any additional comments like this.