[belyro]

This question may seem odd, has anyone else found that their insulin:carb ratio actually changed with different levels of carbs?

I've been eating lower-carb meals lately than usual. Normally I take 9 units for a 55g lunch. That would tell me that if I have a 20g lunch I should take 3-4 units, right? Well that sent me up to 15 (270). There weren't any other variables or "hidden carbs" that I could think of. This has happened more than once.

Anyone have any possible explanations or similar experiences?

[Funnygrl]

I use a higher carb ratio with pizza than I do other foods. I know when people have a higher bs they often need more insulin than with a lower bs, so it may be the same concept.

[MJM]

Originally Posted by belyro

This question may seem odd, has anyone else found that their insulin:carb ratio actually changed with different levels of carbs?

I've been eating lower-carb meals lately than usual. Normally I take 9 units for a 55g lunch. That would tell me that if I have a 20g lunch I should take 3-4 units, right? Well that sent me up to 15 (270). There weren't any other variables or "hidden carbs" that I could think of. This has happened more than once.

Anyone have any possible explanations or similar experiences?

Beth, I use different carb ratios for each meal. It's not just one thing that has to be taken into account, I think. I'm not an expert on this, so it's just my opinion, but the GI index of the food can determine what carb ratio you might use. For instance with a low GI (Glycaemic Index) food your release of glucose will be spread out over a longer period of time. High GI foods on the other hand release the glucose quickly/immediately, ie. glucose itself would be instant. This of course would tend to give you a spike and you may require y more insulin for this. I've tested this out but only once. I took the same food for both breakfast and lunch but I still needed a different ratio. That's something you will learn by experience. In fact it changes for me also with the seasons.
I might be odd but that's what happens. So don't worry about it if you have to change your ratios.
Someone with more knowledge than me might give you better advise on this. I do know, for sure, it's nothing to worry about though.

[belyro]

I definitely know that there are a lot of variables (e.g. time of day, GI, amount of grease in the food, etc.), and I do adjust my ratio accordingly.

I'm just wondering if there's any chance that the level of carbs alone (i.e. without the influence of any of these other variables) could change my ratio.

[linda53]

MJM where have you found the best GI book or info on the net.? I don't want to go and buy a book that doesn't give me what I need.

Thanks
Linda

[BlueSky]

Originally Posted by belyro

....I'm just wondering if there's any chance that the level of carbs alone (i.e. without the influence of any of these other variables) could change my ratio.

The short answer to that is "yes". The reason being that insulin doesn't only get used in the metabolism of glucose. It is also used in lipolysis (the breakdown of fat) and in the uptake of amino acids (metabolism of protein). So if you had a meal that wal all fat/protein and no carb, you would still need insulin with it. And if you didn't supply any, your blood glucose would go up. Simply because the basal insulin that should be keeping youBG down would be used for other things.

The net effect of this is that, the less carb you eat in a meal, the higher your insulin:carb ratio needs to be. I inject 8 units of Actrapid to cover a breakfast that is virtually all fat and protein. And if I don't do it, my BG goes through the roof.

[belyro]

Originally Posted by BlueSky

The short answer to that is "yes". The reason being that insulin doesn't only get used in the metabolism of glucose. It is also used in lipolysis (the breakdown of fat) and in the uptake of amino acids (metabolism of protein). So if you had a meal that wal all fat/protein and no carb, you would still need insulin with it. And if you didn't supply any, your blood glucose would go up. Simply because the basal insulin that should be keeping youBG down would be used for other things.

The net effect of this is that, the less carb you eat in a meal, the higher your insulin:carb ratio needs to be. I inject 8 units of Actrapid to cover a breakfast that is virtually all fat and protein. And if I don't do it, my BG goes through the roof.

AHA!!! That's exactly what I was waiting for someone to say!

Thanks! This is helpful, because it happened again today! I'm 14 (250) 2 hours after my meal. Ew.

[Injecto]

Wow, that's weird, but your explanation makes total sense. I haven't experienced that as of yet, but for as long as I'm supposed to hang on I'm sure it will happen. I've had ratios being inconsistent as carbs get higher, for example: I need 1 unit for 10 carbs, but I only need 2 units for up to 30 carbs, and 5 units will cover 70 carbs, which makes it hard for me to figure out a ratio.

[belyro]

Ok...so then are you saying that if I have a zero-carb meal, I still need to take insulin?

[Cyborg]

I don't bolus for fat, but I do bolus for protein and carbs. Check this out...

[BlueSky]

Originally Posted by belyro

Ok...so then are you saying that if I have a zero-carb meal, I still need to take insulin?

Yes, absolutely. In fact eating anything that distends your gut will make your BG go up because it causes Glucagon to be released (The Chinese Restaurant Effect). But if the meal contains protein, you definitely need to bolus for it, even if the meals contains no carb.

There is not much helpful mainstream advice available on this, probably because low-carb meals are discouraged. All nutrients are lumped together and a coverage ratio is worked out to cover the combined effect. Because carb is the strongest driver, it is used in the calculation of insulin coverage ratios. Keeps it clean and simple. But, as you have observed, it doesn't always work that way.

In addition to it being poorly understood, covering for protein complicates the control process. Carbohydrate increases BG very quickly (1-2 hours), whereas protein is metabolised over a much longer period (3-8 hours is my guess). So typical advice is to cover for carbs when you eat and do corrections afterwards, which effectively covers the protein.

If you have a pump, you can do an extended bolus, which is suggested in Cyborg's reference. But it is more difficult with MDI. Humalog, Novorapid or Apidra injected when you eat won't do the trick. Their action is mostly over by the time protein starts increasing BG. Either you can split the dose, taking some of it when you eat (this also covers carb in the meal) and the rest 2+ hours later. Or you can use regular insulin (Actrapid, Humulin R), which acts over 8 hours, instead. I always use Actrapid before breakfast, which is mostly fat and protein. And it works very well.

[LancetChick]

Yeah, I use Regular when I eat a fair amount of protein. A breakfast of 3 eggs and 4 pieces of bacon without any carbs costs me 2 units of Regular. If I were to add toast, I'd mix the Regular with Humalog.

[belyro]

This is helpful! Thanks guys!

[Cyborg]

Originally Posted by BlueSky

In fact eating anything that distends your gut will make your BG go up because it causes Glucagon to be released (The Chinese Restaurant Effect).

I'm still doubtful of this theory. I don't ever seem to need to over bolus when if I happen to eat a lot. And I've never seen my bg rise due to extending my stomach with water...

[tanyatype1]

Hi Belyro! I don't bolus for a 0 carb meal and I don't go high. I have eaten steak and no change to bg. Same with chicken wings - I have eaten them dozens of times since dx and never take insulin and my bg's don't go up. I've been adding extra insulin lately for high fat/protein meals if I'm also having carbs in the meal, but otherwise, notta!