Glucose Spikes and Dips

Possible a little complex for here but worth an ask anyway. Maybe @Dr_Alex_Harrison might have some thoughts. How harmful are glucose spikes to the normal no diabetic person?

I ask as i recently started using supersapiens just as a bit of fun and interest in data and it seems to appear from the data any decent amount of carbs ingested in a meal (over 40g) causes a big spikes, dip and then sometimes another spike again after.

If they are bad per say then how the hell does one get the recommended carb consumption in for a day without spiking this constantly which we know is bad for overall health. This does also go along with my previous thought of being rather carb and insulin sensitive.

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Answering a T1 diabetic, it depends on what you are eating (cake, potatoes will absorb quicker than rice and pasta and cause less of a spike), when you are eating, how long after exercising, how much fat is in the food you are eating (fatty foods slow consumption, pizza is a nightmare for me), and (along with a load of other things) what you are doing after you eat

I was told (as a T1) not to get to upset about the spikes, it’s always going to happen, it’s the average that matters

And what are you considering a big spike ?


I guess it comes down to the other nutrients you ingest along carbs thatreduce these spikes; namely healthy fats.

Also a variety of carbs, not just high glycemic ones but also lower and mid.

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This is the issue with these devices if you don’t know what it all means.
What you are describing, a spike, dip and rise again is normal.
Unless you have negative health and wellbeing associated with spikes and dips, then you are ok.
“spiking this constantly which we know is bad for overall health”…no
First read up on what it all means, then use the device. Now you are making conclusions that are wrong, possibly taking incorrect actions, etc.

From an artcle: Those with a biphasic curve display better insulin secretion during the first phase and have greater insulin sensitivity.

So better


Wearing a CGM at the moment too. Second time after a first dabble into it 3 or 4 years ago. It is interesting to note how different meals affect BG levels. My banana porridge produces only a small peak, white bread (which I actually eat with veggies … different story) a large peak. However, I’m down to fasting levels quickly.

One observation compared to a few years ago. Peaks are not as pronounced and disappear quicker now. I’m wondering if my training volume (15-20 h/wk for the last 4-6 years … don’t recall exactly when I bumped up volume) has anything to do with this. Isn’t this what all this zone 2 training is supposed to be good for.

However, I’m wondering myself about all these guidelines/recommendations on BG. Are spikes bad for the healthy athletic population? Or is it more important how fast these spikes decline? Once again one of these issues with new gadgets, we measure but we don’t really know how to interpret it. I don’t read too much into it, I’m just curious. I will wear it for the 2 weeks and that’s it.

By the way, this piece is sort of interesting:

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Yeah this is the issue i see. A lot of the information out there is for the unhealthy population who do little to no exercise and eat a less optimal diet.

Just for context this is the double dip i am referring to post dinner. Seems to happen with both my preferred carb sources that agree with my gut and IBS, white rice (basmati or sushi) and sweet/normal potato.

Well that doesn’t have a scale on it, so it’s just a very pretty graph, whats the top of the blue bar (on freestyle libre the range is configurable), second spike is probably the rice, first spike sweet potatoes

And when I say spike, I mean it went up, depending on what the upper scale is and how high those raises actually are, it looks like normal body behavior, food takes a while to digest and does it a different rates, it’s why when you have a glucose screening test (to see if you have diabetes) you are asked not to eat for 8hours+ before the test,

Did you do anything after eating (remember as a T1 doing and not doing the washing up makes a difference to bs)

Does the sappions give a estimates hbca1 ?

Sorry, should have said that is peaking about 175/180. Yes, the dip probs coincide with a post-meal walk.

Though im now thinking it isn’t accurate at all. I know it can be 5-10 mins behind due to the say it works but the app says 90ml/dl currently where a finger prick and my personal feelings (low sugar) give 50mg/dl which is hypoglycemic. This means those big spikes might not nearly be correct or as high.

Actually looking at this graph, if the bottom is 70, and you are currently 86, it would indicate the the top blue bar is about 108, which is bellow human normal range, so those “spikes” are about 126 … which would register on a 8hr fasted test as it would be normal range … I’m out of here

Top of the blue from the app states 140. The 86 is not live at that time but another day.

So the blue bar is normal fasted ranges

They claim glucose loading optimal 80-140mg/dl

If you go to the doctors and do a random blood test, anything under 200 is considered ok (don’t look at when you last ate) , and would not warrant investigation (over 200 doesn’t mean there is a problem just trigger investigation for a more specific test)

Their statement is miss leading and not entirely accurate, like I said … I’m out of here

I totally agree with @Thanas_Stefanes_V

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Yeah makes a lot of sense. almost like they are fueling the fire. That along with that i just tested from a finger prick being completely different gives me little to no confidence in them at all.

Yes it might show a trend but apart from that the numbers seem all but arbitary.

Do they not advise you to calibrate the CGM by confirming with a finger prick?

A couple of notes - my wife has been using a CGM for optimal metabolic health. She’s using a Dexcom.

Her doc wants her under 200 post meal. Glucose spikes are a normal fact of life so trying to eliminate them completely turns you to keto or a high fat/low carb diet.

To stay under 200, my wife ends up eating very metabolically healthy IMO. It forces her to severely limit things like rice, potatoes, cereal and sugar. For rice, she can have say 1/2 cup with a meal. For healthy carbs, she can seemingly eat unlimited kale, bok choi, broccoli and other vegetables.

Freestyle Libre don’t, which is what the sapeons is based on, but also there is always (or a lot of the time) going to be a difference between and a CGM and a finger prick, as CGM readings are delayed due to the diffusion time of glucose from the capillaries to the subcutaneous interstitial fluid and diffusion across sensor membranes (CGM sensor isn’t measuring from your blood, and what it measuring from isn’t a fluid)

Finger pricks can also been influenced by debris on the subjects hands

Saw this coming.

I’ll add this to my youtube vid prep list.

Answer: You’re fine. CGM’s are going to create a market of overly blood sugar-concerned perfectly-healthy people.


Exactly the answer i wanted.

That said this morning 1 hour post meal it claimed i was 90mg/dl but i did not feel right, tested with a finger prick and came back as 50mg/dl. Hello reactive hypo. Something is still not completely right but worrying the CGM didn’t pick that up!

Definitely chat with an MD and listen if they say “you’re fine, test less often or forget it entirely.”


Maybe a case again of to much data!

But it is worrying that the CGM’s could be putting doubt in people’s minds when it isn’t needed. What really is is listening to their bodies and performance.

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