Timing of Bolus for certain foods

Can anyone help me with the timing of fast acting doses? My 7 year old was diagnosed in August, so we are just approaching 6 months with this new lifestyle. I thought I had a good handle on his numbers a few weeks ago. Then, just as my confidence peaked, he started getting high numbers again after meals. He always comes down to normal range after 3 hours of eating, but during that 3 hours, it isn’t abnormal for him to hit 300 and stay there or in the high 200’s for the majority of that time.

I have tried playing with the dose during different time of the day. For example, I have gone from 1:30 for breakfast to 1:20 and it seems to be good for one day and then the next day, not so good. I am dosing him 15 to 20 minutes prior to his meal but he still spikes. Am I getting the timing wrong? Could I be missing the insulin once his food processes? Should I be dosing after he eats if he eats things like bread, toast or pasta?

He is on Humalog injections, but we are anxiously waiting for insurance to approve a pump. Does anyone have anything they can offer on when they dose for different foods? I really want to get a handle on his numbers so he can focus better in school.


hi @Karolyn7

okay, so you’ve noticed that “fast-acting” insulin is not as “fast” as it needs to be. this is something I have also observed.

the other observation I want to mention is that if you do inject enough and early enough, you will most likely “crash” "(very low blood sugar) at +4 to +5 hours after a meal, this is because our “fast” insulin hangs around for (on the average) 4-5 hours, which is way longer then insulin is supposed to hang out.

so the protocol for figuring out if your fast acting injection was enough, is that at +2 hours after the meal, your blood sugar is approximately +50 mg/dl above your pre-meal blood sugar. That’s it. That can mean you may see a +100mg/dl spike at +1 hours after a meal or a +whatever at 30 minutes, etc. flattening a post meal spike is very difficult to do. most people do not bother checking before +2 hours, honestly, most people just check right before the next meal. even a cgm can miss the peak because it can lag reality by 30 to 40 minutes.

please check out “Using insulin” or “think like a pancreas” for much better reading on this subject.

there are a couple of ways that I have found that can work. 1) toy with glycemic index, really fast absorbing carbs will spike your bs in the hundreds directly after you eat because they absorb much faster than insulin. IN contrast, pizza or ice cream will absorb much much slower than fast acting insulin and cause spikes many hours after eating them. by mixing carbs with fat and protein… you can come up with combos that will work better, or 2) eat much smaller amounts of carbs. limiting carbs will limit that spike very consistently, finally 3) introduce mild exercise, such as a post meal walk. even 15 minutes of mild activity can double the action of insulin.

please work with an endo or CDE especially if you are not comfortable with making medication changes. insulin is tricky but you seem very observant so I think you will get pretty good at it! A pump will not change this particular thing, as it uses humalog/novolog/apidra which are all essentially the same as what you are doing now. good luck.

We have an 8 yr old son, dx’d at 12 months. I have been experimenting with adding fat first to slow down the carbs while the insulin catches up. This seems to be helping. I bolus for the carbs right before he eats, if I add a few min before there is less of a bump but no spike either way. Too long of a prebolus and he went low. I did have to tweak I:C ratio and basal when I first started.

I totally agree with Joe about contacting CDE or endo if you need help adjusting insulin.

Ditto what Joe says. But having a pump will help you with certain foods. Your pump trainer and CDE will have him eat very low-fat foods with very precise carbohydrates (ex. boxed dinners like Lean Cuisine or a sandwich on packaged bread) so they can help get his basal (baseline) rates and bolus (fast-acting) ratios set up right, and chances if his post-meal BG’s have been high then the ratios will need to be higher. Then once that’s set, you can start experimenting with higher-fat foods like pizza or ice cream. The “dual-wave” feature allows you to deliver a percentage of insulin up front, and delay the remainder for anywhere from :30 to 8 hours. It’s much more like a normal pancreas functions.

Keep in mind your son may still be in the “honeymoon phase”, where he is still producing some insulin but not consistently, so that might be throwing off the numbers too. Usually they like kids to have been diagnosed at least a year ago before approving the pump because of this possibility. Hang in there…it is a lifelong process trying to learn to mimic a busted pancreas, and unfortunately it is by no means an exact science. So you do the best you can.

Thank you! I am taking your advice and re-reading my Think Like a Pancreas Book… I am also going to try charting his 2 hour post meals as suggested. I usually wait for three hours because that’s when I have been instructed to correct by our Endo. Hopefully the 2 hour check will confirm the dosing. I think I depend too much on the CGM and it starts to drive me mad.

And yes… the honeymooning keeps me on my toes. I was starting to think maybe we were heading out of that phase with these higher numbers.

Thanks for the responses. I really appreciate the support!

Hey there Karolyn.
I thought I should pitch in a little knowledge of the ancients. Remember that during digestion everyone has a spike in sugar levels so be careful of over control using insulin. Exercise is great after meals. After 49 years of this I just did 2 miles in 24 minutes. CGM is the best tool in combination with Lantus. IMHO
Good luck and press for the cure!

Hi Karolyn,

I have been trying another approach to keep from going so high after meals. I am using a symlin injection along with all the other tools: dual wave, paying attention to food type and mixing, pre-dosing, etc. that have been addressed. It further complicates things but it has allowed me to drop my A1c and lower my post meal spikes. Many people have figured out how to lower the post meal spike without using Symlin but for me for now it has helped me and I don’t mind the additional injection along with the many ways the dosage from the pump can be tailored to you.

Have a great day!


I wanted to send post a quick update and a big Thank You to those who responded to my post. As it turns out, I was not giving my son a large enough dose of insulin. I did some experimenting at the two hour mark sugar checks and started increasing his insulin to almost double the dose I was giving him. He maintained much more reasonable numbers with this new dose. Of course, I sent all my data to our Endo, who liked our new ratios and results.

He even ate cereal yesterday for breakfast and maintained a decently flat line on his CGM! :slight_smile:

I really appreciate the support and comments.