Sugar Surfing : "Watching the bend in Dexcom"

Sorry if this has been covered elsewhere:
I just started to read Ponder’s Sugar Surfing and read the part about watching the bend about pre bolus, and when to eat. It makes a lot of sense, for example, if the pre meal BG is 100. There is a 20 min lag with the CGM. As the CGM starts to indicate BG trending down, the insulin has started to work.=> Ok to eat.

Does it still make sense to “watch the bend” if pre meal BG is 80? If someone pre - bolus with a BG =80, is there a risk of hypo as insulin begins to work and food has not yet begun to digest? perhaps a shorter pre bolus time?

If the BG at dosing is 80, then you could fingerstick at 15 minutes or so and see if your BG is dropping. From experience you may learn how much time it takes for insulin to make your BG trace bend. For me it’s 45-60 minutes in the morning and 30 minutes for dinner. I usually like to wait for the bend but if it’s impractical, like when your BG is relatively low, then taking an educated guess is the next best thing.

i wonder about this too. why do i need to wait for the insulin to start doing its thing and trending down when i want/need to eat? maybe this is an idiotic question. i usually wait 10 minutes after pre-bolus for my meals. this seems to work for me. also, when i go out to a restaurant i am too nervous to bolus after i order; i want to see the food on my plate before i bolus. could you share your opinion? am very curious.

Insulin action can vary from meal to meal. “Waiting for the bend” is an advanced technique that does work but is not without its own risk. Like many insulin-dosing techniques, it is not for everyone. As you well know, diabetes has no trouble producing anxiety even under the most normal of circumstances. We each need to balance risk and reward. If this method adds anxiety then it’s probably not worth it for you.

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10-15 minutes was what I was always told from back when I was on MDI. But since getting a CGM I’ve been much more aware of how high I’m spiking post-prandially, particularly lunch time which is when I give myself permission to have some carbs. So I’ve been “watching the bend” to keep that in check, and I find I need to bolus about an hour in advance, not the 15 minutes I was originally told.

Obviously this is another of those YDMD things and totally depends on your own metabolism and sensitivity and weight and activity and…


I took me a long time to realize that people who give advice like this are thinking of the average diabetic. They are hyper-fearful of anything risky. In my opinion, so risk-averse they lose much of their value. I learned my best management practices once I decided to question everything the medical establishment taught me from diet to exercise to insulin dosing. They’re not talking to me; they’re talking to a larger diabetic population with one eye on their legal defense.


"I find I need to bolus about an hour in advance,"
Wow, bolusing about an hour in advance is not easy because “life happens”, and you may not be able to eat as planned.

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If I bolused an hour ahead of eating, I’d be in trouble. Are we talking about bolusing an hour ahead, using Novolog or Humalog??? LOL!!

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Humalog, and yes. In fact today it was about an hour and 20 minutes before the curve finally started to bend down. Sometimes its sooner–more like 30-40 minutes. Seems to vary with factors such as the level of stress at work (currently high), whether I’ve ridden my bike to work (too rainy today), and where my BG is when I test (today, 144; see previous note re stress).

The point is not about bolusing an hour or more in advance; it’s about using the Sugar Surfing technique of waiting for the bend in the CGM trace before eating. Ponder makes it abundantly clear to always have your safety glucose nearby and also no impediments to plating your food on short notice. This book’s thesis is that diabetes is a dynamic disease that responds best to living and reacting in the moment. We differ from each other and ourselves, when compared day to day.


I’ve had times when I’ve done boluses simply because I’m high–no intention to eat, so I can understand that aspect of it, OR the possibility that there are times when ones bg’s simply don’t want to descend to normal or hypo levels using our usual amounts of insulin. By and large, I bolus a few minutes before eating, or right when I start, or shortly thereafter, depending on my bg readings, AND their stability, or lack thereof.

Back before “fast acting” insulins we were told to wait an hour. And I remember as a kid, life happens. But when you go through those advance insulin classes they had way back then, life doesn’t happen. They just always think we life perfect days, that always behave he same way everyday. I have found everyday is different and what worked last week might not work this week. So right now waiting that 20-30 minutes seems to work except when at work and I only have that 30 minute lunch. I don’t usually watch for that “bend” but I will start looking for it. Once again, learning something new. I have learned I never know it all even after 45 years.

I don’t remember that. I remember the “rule” being roughly 30 minutes. I looked up onset for regular and it’s 30-45 minutes. In practice, back in the bad old days of regular, I couldn’t last an hour after a bolus, without eating.

It’s so weird how much variability there is in this stuff. When I was on R/NPH I just did 'em both in one combined shot in the a.m. I always understood from the graphs and info they gave me that that gave me two peak times, one around lunch time and the other around dinner. And it seemed to work out that way. I certainly never bolused for meals separately. On the other hand, when I finally got a referral to Joslin the first thing my new endo told me was “Well, you’re not doing too bad at managing this considering the way you’re doing it makes no goddamn sense” (he was a bit of a crusty old guy). So who knows. Hey, I was just doing it the way they told me (for twenty years!). I’d tried to get my physicians to considering putting me on basal-bolus MDI, which I’d heard about at a party from a T1 who was tthe ex-husband of a friend, but I could never get past The Great Wall of “Your numbers are ok let’s not change anything.”

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I’ve never been one of those that follows the rules. Here I sit waiting for that bend. Tested at 6 94. Tested at 7:10 for meal 92 steady arrow. Bolused and waiting. It is now 7:50 and still no bend 91 with steady arrow. Everyone’s diabetes may vary and probably will at some point. I’ve said before and will say it everyday, what works for me today may not work for me tomorrow. Makes it very challenging to manage this, doesn’t it?

What did you do? Did you finally eat? What were your post-meal numbers? Do you think this scenario is typical for you? I’m just curious; I’m not challenging your report.

I pre-bolus anywhere from 20 minutes to an hour before eating. If I’m on the low end and don’t have much to drop then it’s 20 minutes. If I’m on the high end, it’s 30-45 minutes. If I’m quite high, then I wait until I come down, which can be an hour or more.

I do not eat low carb (but I do eat moderate-low GI and limit carbs to at most 50g in a meal) and pre-bolusing makes a big difference in my after meal spike. I can only imagine the difference it might make for high-GI meals!

The insulin peak is anywhere between 1.5 to 2 hours from time of injection. If someone begins to eat at 1 hour (or even longer) after injection, wouldn’t the food peak and the insulin peak be mismatched? I understand the reason to delay if the pre meal BG is high, then one would want to wait until the BG number is lower before eating.

My question : Is BG management primarily about trying to match the “food/digestion and their peak effect on BG” with insulin peaking?

what on earth do any of you guys do at a restaurant w/ all this pre-bolusing? and, just a point of reference, i can show a straight arrow on my cgm while my bg is still trending up or down. i haven’t been finding that trending arrow that helpful. not to say i don’t rely on them at all; but, if something seems out of wack, i do a finger stick to double check. also, as far as those arrows go, i have many many times, seen the arrow pointing down fast one minute, and a minute later it has straightened itself out. how do you deal with this? i’m very curious.

I rarely eat at restaurants (I have severe food allergies in addition to diabetes), and when I’m “forced” to eat out due to work or social events, I typically get a salad which tends to be low carb anyway. When I used to eat at restaurants more often, I would bolus for what I thought I’d be eating when I sat down (underestimating if I wasn’t quite sure), and then I’d bolus the rest when the food came. Usually it’s at least half an hour between first sitting down and actually beginning to eat a meal. But this was all without benefit or a CGM or pump, so I’m not sure if I’d do things differently now.

I also ignore the CGM arrow. I find it quite useless, actually, as it only picks up pretty sharp rises or falls in blood sugar. I have the “rise” and “fall” alerts on my CGM turned on, but usually by the time they go off I’m already aware that I’m rising or falling. I find it much more useful to look at the actual line to determine if it’s trending up or down.