• Guest, the forum is undergoing some upgrades and so the usual themes will be unavailable for a few days. In the meantime, you can use the forum like normal. We'd love to know what you think about the forum! Take the 2025 Survey »

Carb Counting & Pen Types

DisFanJen

Well-Known Member
So, I'm fairly new to this insulin lark but doing pretty well (Now I've got the regime sorted it's 4s and 5s most of the time, and the highest being a 6.), however I'm on a fairly strict carb regime so I don't have to vary my insulin intake.

I'm off on a cruise soonish (Woohoo, Disney UK Staycation cruise!) so need to look at varying the insulin to the carbs rather than the other way around.

So, does anyone have a semi-definitive calculation I can throw into excel to work out my carb ratios & correction dosage ratios? (I know my diabetes team should go over this with me, they screwed up and there referral to talk to the right team again might not come in until after the cruise). I've got my injections, carbs, and levels all in a spreadsheet (like I said new to this so overcompensating) so should be easy to apply a calculation.

Please note I understand anything said here is a personal opinion and the diabetes team should be my first port of call. I'm just trying to get something in place if they don't get back to me in time.

I grabbed the RapidCalc app for my phone and it looks pretty good, but the numbers in there at the moment best guesses. I'm not actually using the numbers it suggests yet, but rather seeing if the numbers it thinks I should have are close to what I'm currently taking given the carbs I'm eating.

Also, what are peoples thoughts on re-usable pens? I'm on disposable right now and I'm thinking the chance to do .5 of a unit would be very helpful as a couple of times I've thought I should drop by .5 as my evening numbers were a little lower than I'd like (luckily no hypos yet, well, one potential one but that was because I was distracted and injected too much, so I nommed down on something sugary before it could hit).

Lastly, Hi, I'm new! How's everyone? ;)
 
Calculating insulin base don what we eat is down to what our insulin to carb ratios are.
If you eat similar meals all the time and know how much insulin to take you could try calculating the ratio that you are using - count the carbs and divide by the units of insulin that you take.
As as guide (but only a guide), it is common to start on 1 unit of insulin to 10g carbs and then adjust accordingly.

Regarding re-usable pens - yes, yes, yes. I have no idea why anyone would want to use disposable ones if they had a choice (I appreciate we don't always have a choice). Not only do they come in half unit doses, they are more robust, the cartridges take up less space in the fridge (or luggage when travelling) and produce less waste so better for the environment. It is very easy to change the cartridges so there should be nothing to worry about there.
They don't last for ever so make sure you get two pens per type of insulin - one main one and one spare. And try to get different colours for bolus and basal so you don't confuse them.
 
I've got my injections, carbs, and levels all in a spreadsheet
This sounds like you already have the calculations. If you know how many carbs you had, how much insulin you took and if this works out well, you know how much insulin you need for that amount of carbs on that time of day (bar all the other variables like exercise, illness, sleep, being on holiday, etc.).

[The numbers in the next piece are an example, and NOT a suggestion to use this amount of insulin, as our ratio's differ from person to person!]
For instance, if your breakfast was 20 gr of carbs, you took 2 units and this kept your levels where you want them, it looks like your I:C ratio for this meal is 1:10. To see if this is right, next time try a 10 or 30 gr of carbs breakfast with the same ratio and see if this works.
I grabbed the RapidCalc app for my phone and it looks pretty good, but the numbers in there at the moment best guesses. I'm not actually using the numbers it suggests yet, but rather seeing if the numbers it thinks I should have are close to what I'm currently taking given the carbs I'm eating.
I don't use apps to work out my doses, but I can understand how they could be useful. What does this app base it's decisions on? I'd expect if you feed it your ratio it would come out with the same dosing advice as you would.
Also, what are peoples thoughts on re-usable pens? I'm on disposable right now and I'm thinking the chance to do .5 of a unit would be very helpful as a couple of times I've thought I should drop by .5
Yes, disposable pens all the way! Especially if you take low doses being able to use .5 units is very useful!
It also means less waste, and much less room in your fridge :)
I don't know what insulins you use, but if it's Novorapid or Fiasp, the Novopen Echo also has a little screen where you can see your last dose, very useful!

edit:
Lastly, Hi, I'm new! How's everyone? ;)
Hi @DisFanJen , and welcome!
I'm fine, thanks for asking. Hope you're doing well as well. :)
 
Calculating insulin base don what we eat is down to what our insulin to carb ratios are.
If you eat similar meals all the time and know how much insulin to take you could try calculating the ratio that you are using - count the carbs and divide by the units of insulin that you take.
As as guide (but only a guide), it is common to start on 1 unit of insulin to 10g carbs and then adjust accordingly.

I think what I'm after is a calculation to dial in the ratio.

Something like <before GL> - <After GL> / units = carb ratio
(I know that calc is BS, I just needed to put something in there :) ).

Regarding re-usable pens - yes, yes, yes. I have no idea why anyone would want to use disposable ones if they had a choice (I appreciate we don't always have a choice). Not only do they come in half unit doses, they are more robust, the cartridges take up less space in the fridge (or luggage when travelling) and produce less waste so better for the environment. It is very easy to change the cartridges so there should be nothing to worry about there.
They don't last for ever so make sure you get two pens per type of insulin - one main one and one spare. And try to get different colours for bolus and basal so you don't confuse them.

That's my thought too. It's got to be better all round, going to contact the team and see if I can switch once I've used up my current allocation.
 
This sounds like you already have the calculations. If you know how many carbs you had, how much insulin you took and if this works out well, you know how much insulin you need for that amount of carbs on that time of day (bar all the other variables like exercise, illness, sleep, being on holiday, etc.).

[The numbers in the next piece are an example, and NOT a suggestion to use this amount of insulin, as our ratio's differ from person to person!]
For instance, if your breakfast was 20 gr of carbs, you took 2 units and this kept your levels where you want them, it looks like your I:C ratio for this meal is 1:10. To see if this is right, next time try a 10 or 30 gr of carbs breakfast with the same ratio and see if this works.

I think I was hoping for a definitive formula I could apply to the spreadsheet figures. I'm an IT geek and we like facts and figures.

I don't use apps to work out my doses, but I can understand how they could be useful. What does this app base it's decisions on? I'd expect if you feed it your ratio it would come out with the same dosing advice as you would.

That's exactly how it works. I put in the numbers, 1:6 for b'fast and dinner, 1:5 for lunch (I'm Type 2 and they still have me on two Metformin a day strangely so the absorption is better when I take those) and it works out the units based on a carb slider. It seems pretty close but the correction numbers are a bit of a guess so I don't 100% trust it yet.

Yes, disposable pens all the way! Especially if you take low doses being able to use .5 units is very useful!
It also means less waste, and much less room in your fridge :)
I don't know what insulins you use, but if it's Novorapid or Fiasp, the Novopen Echo also has a little screen where you can see your last dose, very useful!

I'm on NovaRapid and Lantus. The Lantus at 18 seems dialled in so I'm going to ask for a switch to the Echo. :)

Hi @DisFanJen , and welcome!
I'm fine, thanks for asking. Hope you're doing well as well. :)

Yup, took a health scare but I'm the healthiest I've been in years so the scare was the kick up the butt I needed.
 
I think I was hoping for a definitive formula I could apply to the spreadsheet figures. I'm an IT geek and we like facts and figures.



That's exactly how it works. I put in the numbers, 1:6 for b'fast and dinner, 1:5 for lunch (I'm Type 2 and they still have me on two Metformin a day strangely so the absorption is better when I take those) and it works out the units based on a carb slider. It seems pretty close but the correction numbers are a bit of a guess so I don't 100% trust it yet.



I'm on NovaRapid and Lantus. The Lantus at 18 seems dialled in so I'm going to ask for a switch to the Echo. :)



Yup, took a health scare but I'm the healthiest I've been in years so the scare was the kick up the butt I needed.
Hi. To switch to an Echo pen your Basal insulin would need to change to Levemir. It's slightly more expensive and usually needs split injections but is a good insulin many of us use.
 
Hi. To switch to an Echo pen your Basal insulin would need to change to Levemir. It's slightly more expensive and usually needs split injections but is a good insulin many of us use.
Or use Lantus in a different type of reusable pen. I have never had single use pens and been using Lantus for over 15 years.
I think it use the AutoPen. Not sure if has the countdown counter though.
 
Back
Top