Habits of a Great A1c: Carbohydrate Intake

No great surprises here …

Diabetes Daily Poll


I do have a problem of course with them extrapolating that because only 22% of type 1’s consume a low carbohydrate diet, only 22%, but then they derive 22% means it is better being low carb? When 78% do not low carb and have the same A1C? But again somehow 22% is better? In type 2’s it is more, but still only 32%.

Sure a higher percentage of people are low carb in the controlled under 6.5% group versus than the amount in the over 8%. But a vast majority do not low carb, so why say it’s better?

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I just re-read the entire article and didn’t see where they stated low carb is better?

They did say

“A lower level of carbohydrate intake was associated with having a more optimal A1c level among patients with type 1 and type 2 diabetes in this survey study”,

but they also said

“… there was a considerable proportion of people who ate >100g per day in the lower A1c group (~22% among the type 1 population and ~11% among the type 2 population), highlighting that it is certainly possible to achieve recommended A1c targets on a higher carbohydrate intake”.

My takeaway is they’ve concluded it’s easier to maintain an A1C under 6.5 with a carb intake lower than 20 grams/day than it was for those who consumed > 100 grams/day.

BTW, I had a pizza Monday night and ate > 120 grams of carbs :crazy_face:. I stayed in range 100% of the following 24 hrs with an average BG of 5.1 mmol/L (92 mg/dl), so as long as you know what you’re doing, anything is possible :yum:


What they are saying is eating very low carb is correlated with lower A1cs among diabetics in that 22% of the lower A1c group eats very low carb, but only 7% of the higher A1c group eats very low carb. It’s not in any way suggesting you need to be low carb to be in the lower group (clearly not, as a majority do not), but that if a T1 diabetic does eat very low carb, their odds of being in the lower A1c group are higher. So those data do support a possible beneficial effect of low carb diets, not as the only way to have a low A1c, but it may be that if you eat low carb, it’s then easier or in some way more feasible to have tighter control. (Granted, it’s also entirely possible that there’s some unmeasured confound, like people who eat low carb are also more likely to do X other thing or have X other characteristic, and that’s actually the reason they are doing better.)

Same interpretation for all of the results—each one is a factor that increases odds of being in the low A1c group, which means basically a disproportionate number of people doing that thing (using a pump for example) have lower A1cs, enough so that it is unlikely to be due to chance alone.


The research is very interesting,

@Jim_in_Calgary I guess I mean this as a takeaway…it just seems like 22% or 32% for low carb should not be listed in the common management, when CGM, settings etc are way more common? And more common is the other 78% that don’t do low carb?

And I get a higher percent use low carb to control their levels versus the percent that use it and are still high, but it is not the majority of the people that do control it at those levels so how can that be a key takeaway?

Key Takeaways

Based on this survey data, the common diabetes management habits reported among patients with lower (<6.5%) A1c as compared to those with higher (>8%) A1cs are:

Type 1 and Type 2 Diabetes
  • Consume a lower-carbohydrate diet on a regular basis.
  • Use an insulin pump.
  • Exercise regularly.
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I get what you’re saying to @cardamom, in that if you low carb you are more likely to be controlled, but that would be if you low carb. If you don’t low carb you are more likely to not be under 8%.

I get that…but I also get that still most do not low carb and that is still not the higher numbers of being under 6.5% that say CGM usage is or even CGM alert settings, so why pull out the low carb as a takeaway?

I’m scratching my head how you could eat <40 carbs a day and end up with an A1C over 8… did I read that right??

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Well, your basals and ratios can be totally off.


@Jim_in_Calgary ooh pizza and stayed within range!!! I know you enjoyed that!!!

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People who purposefully eat less carbs primarily because they are more conscientious of their BG, are also more likely to do so many other things helpful to manage their diabetes than those who just eat whatever they want and do not care about their BG.

That’s the problem with these types of reports.

A much better comparison would be two groups of people who are very involved and meticulous about their diabetes management, one group is low carb and the other is high carb. Compare those groups.


@Eric2 Even better would be a group with next to no carbs (< 20 g/d) vs higher carbs (> 100 g/d).

As I mentioned to @Marie20, I ate > 120 grams / carbs the other night and stayed in range. What I didn’t mention is that I had to pre-bolus / bolus / extended bolus 18 units of insulin just for the pizza. That’s more insulin than my typical total daily dose. It’s a lot of work - not sure I’d want to do that 365 days a year.

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@Jim_in_Calgary yea, I would say it’s definitely easier if you don’t have to figure carb ratios and extended boluses because you’re not eating the carbs in the first place to have to do that.

It has been pretty easy for me as usually I am low fat, So the basic half a half hour before I eat and then the rest when I eat usually works pretty well. I just put it into my pump a half hour before I eat and extend the rest for when I’m going to eat.

But for me throw in a very high protein food with low carbs and I struggle to figure it out. Throw in a higher fat food and I am usually okay as long as it’s something like avocado on a salad, a handful of nuts in my veggie bowl. But the fats can vary what else I am eating sometimes. And sometimes that’s harder to judge. Usually I just add more insulin if needed later.

I had coconut whipped cream the other night, first mistake eating at night. My hubby had just brought it home a few hours earlier. But I thought 6 carbs not a big deal, I’ve had 6 carbs at night off and on. no problem, dosed for it. But coconut whipped cream 6 carbs, 4 grams of fat, the ratio!!! I just didn’t think of that. Duh, 2 hours after I’m asleep my BG shot up to 160 and of course pretty much stayed there because mostly no extra for it then! And from 90 to 160 why???

Well it was meant to be a treat, but I am not seeing it in very good light right now lol!!!

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I’ve found fats are always challenging to deal with, be they with carbs or protein. I’m a lot better at it now but I watch my CGM like a hawk and micro-bolus (sugar surf) to keep the numbers in range.

We all have bad nights. That’s why they created new days :slightly_smiling_face:


I think studies like this are very useful and very needed! Most people struggle to get an A1c within the target range (≤ 7.0%). I was one of them for many years, and even now, I can easily hit 7.0% if I’m having control difficulties. It can be really helpful to look at a list like the one generated from this study and compare the habits of those in the study to what you are currently doing to see if anything could be improved. It doesn’t necessarily mean any one of these factors is “better” than another, but all of them are things people can try if they are trying to lower their A1c.