Lows after dinner

Hi again,
The past couple nights I’ve been going low right after dinner. I seem to be bolusing right, 1 unit to 15 carbs, and then not long after eating id start to drop rapidly. So then tonight I had my cheat meal some wings and fries, 40 grams of carbs for the fries so i only took 2 units to bolus for 30 grams of the fries to see if that extra 10 would keep me in range or even a little high but i again started to drop reaching 70’s. Treated the low with juice, 10 or 15 minutes and was still dropping to low 60’s. I was able to get it back up after about 30 minutes of juice and glucose tablets. I didn’t have a workout today or anything to strenuous that would make me drop like that. Any ideas as to why this happening or what i should do to correct this? And this only happens at dinner. I had oatmeal this morning (30 G’s) and did the correct bolus (2 units) and seemed to even be high later on in the afternoon maybe 200’s. Any help would be great.

From, Benjamin

hi @Ben115, I forget do you have a pump?

anyway, 2 things come to mind - 1 - fries and wings are SUPER fatty, meaning the carbs will be delayed for 2-3 hours. If you bolus fast acting insulin by pump or pen, it is very likely you will go low because the insulin starts to work before the carbs absorb.

or, 2- you are taking too much lantus (or long acting) or your basal is set too high and you were dropping right before dinner.

it could also be a bit of both


Hi Benjamin @Ben115, I agree with what @Joe wrote, and I’ll present one more point for your consideration.

If you are consistently, or frequently ‘going low’ at this time of day following a 1:15 ratio for your bolus insulin, how recently had you validated this ratio? Just because the 1:15 ratio was suggested for you “back then”, doesn’t mean that it will still be right. I know my ratios have changed many, many times over the years; and in fact, at suppertime following a day of heavy labor or exercise, I will use a lesser ratio - such as 1:20 rather than the heavier 1:14.

1 Like

I’m going to assume you have a pump. If you are going low right after dinner, that is more likely to be caused by previous IOB, insulin on board, from lunch or an afternoon snack. Do you check your IOB before calculating your dinner bolus? A second common problem is having your insulin duration, DIA, whatever your system calls it, set to too short a time. The default time for insulin duration is 3-4 hours. The typical actual duration for Novolog/Humalog is 5-7 hours. If the duration is set to 3 hours, you have more IOB than you realize, and it causes a low. I’m having the same problem, and I’ve done extensive tests the last few days to verify it is definitely residual insulin that’s causing my problem. In that case, I have to delay my evening meal bolus.

1 Like

Thanks guys all great information, I use a pen not a pump and have a meal and next dose of insulin always at least 4 hours after. And my long lasting I take about an hour or two before bed but I thought my ratio and or my long lasting might be off so thanks for the suggestions. I lowered my long lasting last night and I’m gonna see what happens tonight and adjust my ratio tomorrow night but try to have few enough carbs tonight not to bolus and see what my numbers do. Thanks @joe, @Dennis, and @mikefarley.

Sorry for that non-relevant info dump. Since you’re on injections, you might want to take a look at Christel Oerum’s blogs at Diabetes Strong, https://diabetesstrong.com/. She is a fitness person and diabetes coach who prefers multiple daily injections over insulin pumps for her personal use. She recently did a comparison of fast and long lasting insulins that might give you more ideas. She likes Levemir for long lasting, so if you search on that you’ll find the article. Good luck!

1 Like

As far as being high in the 200s after what seemed like the correct dose, I often had the same problem after eating oatmeal with nuts for breakfast. I was told to eat more protein instead of oatmeal for breakfast. As much as I like oatmeal (not instant) and thought I was carb counting correctly, I’ve eaten very little oatmeal since then. My endo also changed my morning insulin to carb ratio. In fact each meal is a different ratio.

I agree with the others on the delayed insulin effect when eating a meal with high fats. It has been hard for me to judge also. Its one of those challenges where a CDE can be helpful.

Using the Inpen Smart Pen has been very beneficial in dosing correctly and keeping my numbers more in range.

1 Like