I’m really confused. I follow a 1 unit to every 9 g carb count and that’s what’s entered in on my pump. Sometimes when I eat and I check myself an hour or two after I am perfectly normal, meaning I took the right amount of insulin for the carbs I ate. But other times, I go really low. I don’t understand how this happens because I am entering the exact amount of carbs the box says it has. The first thing I would think is that my carb ratio is wrong, but it works half the time. For instance, tonight I ate yakisoba noodles. It said there was 35 carbs per serving (which the whole thing was 2 servings). So I took the right amount of insulin for 2 servings because I know I would eat the whole thing. An hour later I am 70 and it says I still have 4.50 IOB! What the heck!

How does this happen? Any suggestions on what to change or what I am doing wrong? Thanks!!!

this used to happen to me too until I took into account the fiber. If it is more than 5 grams per serving I have to subtract the fiber from the total carbs and I’m right on the money.

Hi Amanda,

I have totally different insulin to carb ratios (I:C) at different times of the day. Maybe you need to look into that too. For example, here’s what’s in my pump, and what works for me:

12:00am (to 2:30pm) 1u : 9g
2:30pm (to 7:00pm) 1u : 10g (I tended to go low around 6pm)
7:00pm (to 12:00am) 1u : 7g (I tended to go high during this time)

I also have different basal rates for different times of the day. Both work together.

My diabetes educator and I have tweaked the pump since June 1 until it’s working almost perfectly for me (except for those pesky unexplained high days). I send her the pump reports every week and she looks to see if anything stands out for her. It has several times, and we’ve made adjustments.

Hope this helps you.


I’ve been pumping nine years. No foods ever react the same, and carb counts on packages dont always mean a thing to me.
For instance, if I eat pasta and go accordingly, I go low.
It is all trial and error, for some of us really difficult.

I agree with Susi-

Depending on the time of day, your needs are likely to be very different. For example, I tend to need the most insulin in the morning, even though this isn’t the time of day that I eat the most carbs. In the afternoon, I am super sensitive, and my carb ratio is adjusted accordingly. I would try by testing with something with a known amount of carbs that has worked consistently before- not the yakisoba, just in case, and see if you get the same readings in the morning, versus in the evening. If so, then the yakisoba is likley to blame. if you are lower in the evening, adjust your insulin to carb ratio.

Ok thanks everyone! I’m new to this, so I had no idea. I tend to get low at night so maybe I’ll try adjusting my carb ratio 1: 10 g and see if my blood sugar stays more stable. I already have my basal rates set differently throughout the day and that seems to be working. I am taking the most in the morning.

Thank you! I’ll give it a try.

As far as the fiber, do you subtract the amount of fiber from the carbs? Like if it has 10 grams of fiber would you subtract 10 grams from the total carb count? Thanks.

Hey Amanda,
Also keep in mind, that some foods are way slower to digest, like pasta/rice, or meals with a higher fat content. For foods like these, it is helpful to use an extended bolus over a few hours, to avoid the chance of all the insulin working before the food is digested.

On your fiber question, anything over 5 grams of fiber per serving can be completely subtracted from the total carb count. Let us know how it goes!

Do you write your BG down somewhere? i find that I really only get a clear picture if I write them down and what I ate when I am not sure about what is going on. I am also new at the pump and during the first week I was on insulin I was doing my basal testing and wouldn’t you know I had PMS that week without realizing it. My period came a week early- got to love being 42! I haven’t really been eating pasta or rice for that matter so I don’t know how they work . I would see if you can see a pattern and call your diabetes educator and see what you can trouble shoot together.

No I don’t write it down, but I know I really should! I need to get on top of that!