Keeping after meal spikes under 180

From the books I’ve read, they all say to keep after meal spikes under 180, but is this realistic? I’ve been told to test my sugar an hour after my first bite of food and then again at the second hour and my numbers should be lower than 180. This looks okay as far as finger sticks go, because my sugar doesn’t start climing until 1 hour. But the cgm shows me a different picture. I am unclear if this means my sugar should never go above 180, which how can you tell if you are only going by finger sticks every hour. Or if it should be at 180 by the second hour, which is completely different. No matter how hard I try my sugar will climb and go over 180, but will fall back down to about where I started by the second to third hour after my first bite of food. I have tried eating 15 minutes before insulin, after insulin but nothing seems to help. My numbers seem to always climb. But it usually doesn’t stay that high for longer than half an hour. I’d like to know other people’s experience with after meal spikes.

Hello, I wear a CGM and I can watch my sugar level climb to 200 after a meal then comes back down. I’ve learned not to chase my numbers of I will see saw high and low. My rule is if at 2 hrs i’m close to 180 I may or may not Bolus depending on how rappid my sugar level is falling. Good luck and take care

hi @cierhianna, I assign “prefect control” as never going under 65 or over 140. it’s just my opinion.

a CGM can be 20+ minutes behind reality (actual blood/plasma sugar) because it is reading the content of interstitial fluid and not blood. The faster your actual bood glucose is changing, the more incorrect the CGM will be regarding actual, real-time blood sugar. What your CGM says might not be as real as you think.

A finger stick measures blood, so there is less lag(… just a pesky +/- 20% error that is inherent with your bs meter), if you wanted to make a science experiment out of it you would just read finger sticks every 15 minutes for 4 hours (6 is better). the beginnings and ends of each reading will be the test result (extra-credit, draw the error bars for each reading), the in-between values are interpolated (just draw a line between the points) and you will have a pretty good idea of an after meal “spike” looks like.

ways to flatten out the spike:
you are trying to match glucose absorption with insulin absorption and effect. it’s tricky. for most people, sugar absorbs quickly unless it is mixed with fats, fiber, or alcohol. i’d say from your description, unless we are talking about a high fat meal, your insulin starts out perfect then falls a little short (again - as long as the timing of the spike is real and not CGM lag). if your blood sugar returns to within 50 mg/dl of where you started at 4 hours after a meal… taking more insulin is not going to work for you- you’ll be low at + 4 hours.

one thing that might work is adding a 10-20 minute walk at about 45 minutes to an hour after your meal. the idea is that your circulation will increase and your metabolism will be more effective. it could kill that spike that you are seeing if it really does start at +1 hour. just a thought.

the other things that come to mind are messing with the fat/fiber content of each meal and with the total carbs at the meal. more complex solutions exist as well such as a “dual wave” insulin pump bolus (if you pump).

if your a1c is okay and you are not too high or low throughout the day, I honestly don’t think I would mess with it.

I have the same problem. My BG is fine 2 hours later, but those spikes still happen. I find that eating lower-carb meals (<30g) really helps minimize it though.

There are diabetes books and there are diabetes books - what really do the authors know? There are many theories about controlling T1 but I tend to listen more closely to authors who live day to day with their own T1D. The endo I was seeing apologized, after he was diagnosed with late-onset T1, for not fully understanding the complexity of our disease.

Just recently a medical professional told me that I was luck because I have the GOOD diabetes. My reply, “… yeah, just a life sentence that requires continuous minute by minute monitoring and without possibility of parole”.

As @abgivan suggests, your post meal spikes may be controlled by consuming very low carbs at meals; another method is to take your fast-acting insulin before taking that first bite. Be very careful with pre-meal bolus unless you are certain of the delay between injection and action.

When fast-acting insulin was approved in 1996 by FDA, it worked very quickly on me, now its peak action happens much later so I will only test one hour after eating on occasions.

If I have a BG over 100 one hour before a meal, I prebolus for that meal. The prebolus may be one hour, a half hour, or 15 minutes before the meal, as needed. I want my BG to be below 100 at meal time. Knowing how much one unit will lower your BG the first hour after injection is very important, and any active insulin must be considered. The exact routine will vary for all of us, so experimentation is necessary.

I usually avoid fast acting carbs like bread, pasta, rice, etc unless I am going to exercise soon after a meal. I have not had any kind of cereal for many years. A half cup of potatoes, pasta, etc is the max for me at a meal.

I have been a T1D for 70 years, and have no serious complications. I keep my BG below 160 one hour after meals at least 90% of the time.

Thanks everyone for your responses. I’ve only been Diagnosed about 2 years and got on the pump about 10 months ago, so still lerning how to deal. Type 1 is very hard. I have taken the advice about not eating more than 30 carb and waiting 15 minutes before first bite, but I still spike above 180. Even with 25 carbs mixed with fiber and protein I will rise about 100 points from where I started. I’m sure there are foods I can eat with less carbs, but always staying under 30 is a challenge for me. I have also tried taking a little bit of insulin half an hour before my meal dose to bring down my sugars, but I’ve gotten very close to going under 70 which makes me nervous, which prob doesn’t help my numbers. My A1C is at 6.1. I don’t know what scares me worse, long-term complications or severe hypo. I’m just trying to see what is normal, but I suppose normal and Type 1 may not be possible. Thanks again everyone.

I follow Dr. Bernstein’s diet; post meal spikes are hardest to prevent at breakfast, so he recommends only 6 gm of carbs. For Lunch, only 12, and for dinner only 12. ( If you start this you will have to reduce your boluses immediately). Do not eat ANY fast carbs: no potatoes, pasta, bread or even FRUIT. if you are hungry eat more protein foods like eggs, meat, fish, etc. Read his latest book,The Diabetes Solution. He is an endocrinologist and has type one and is now 81 YEARS OLD. He uses regular insulin for meals because that works better with the slow spike that follows a meal with slow carbs and protein.

Hello to Richard V.

From Rich VD.

same with me; it takes a good half hour to begin to see the effect of a Humalog bolus now, peaking around 1 to 1.5 hours, then tapering for the next five hours. When I first started, it hit strong within fifteen minutes.

I also noticed that if I eat before it peaks, I am not as hungry, and the glucose post-meal spike is not as severe. Timing is everything. If I eat too soon, though, the glucose spikes higher and it seems to take longer for the insulin to pull it back down.

Importantly, I learned that the higher my glucose level, the required insulin to act is not in direct ratio. So I need about 3 units at 200, 5 at 250, 6 at 300, and if I go to 400, I need 8 units and about three hours to pull it down all the way to normal.

by “prebolus” do you mean take an early partial bolus, then a mealtime bolus closer to eating time, or is that your full bolus for the meal?

I like my BG to be 80- 100 at mealtime I test one hour before a meal or snack. If I am above 100 I take a small bolus to have a number in that range at mealtime. Sometimes I delay my prebolus to 30 or 15 minutes before eating. All of this is to avoid a big spike one hour after eating. I try to keep my BG 70-160 at all times.

I have learned that when I test before eating a meal, I use the first two digits of the blood sugar number (unless it is a two digit number, and if it is I only use the first digit unless low) to calculate how long I should wait after bolusing before eating. for instance, if my blood sugar is 213, I use the 2 & the 1 to wait 21 minutes after I first bolus to begin eating. I have learned never to eat before bolusing and never to start eating without my waiting period unless I am under 80-85. if I am low, I will not wait, I will bolus and eat immediately.
hope this helps :slight_smile:

From the books I’ve read, they all say to keep after meal spikes under 180, but is this realistic?
Who the heck knows? This is one of those things which is going to vary from person to person. Some people can manage just a mild bump in the BG after a meal. For me on the other hand, I am never too surprised if I pop into the low 200's or perhaps higher. That's just how it works for me.

MY BG doesn’t always come back down after the meal. I use the same carb ratio, same carbs, different BG behavior on different days. It just happens that way for me.

I think the best approach for trying to moderate a postprandial spike is to pre-bolus, possibly also super-bolus, and to do both in conjunction with using a (reliable) CGM.

The CGM is the game changer. A pre-bolus is, after all, essentially just playing a game of “chicken” with a hypo. With the CGM though you can wait for your Sensor Glucose (SG) to start to trend down before you eat. In other words, wait until your bolus is beginning to take effect.

Usually this is about a 1/2 hour for me, but it can go longer.

Last Sunday I changed my infusion site and then pre-bolused for a meal. I then sat back and watched as my BG, which started around 100, just rose and rose while I had not yet eaten a thing. Around the time I was approaching 250 I pulled the set and inserted a new one.

Bad site. :slight_smile: