Type1. Can long term low carbing cause insulin resistance?

[zicksi101]

I'm type 1 and have been 'liberal' low carbing for a year.

I'm on 120g of carbs a day, so my diet is not very low on carbs. For me this diet is not about weight loss; my BMI is 22 and my body fat is 10%, so while I could afford to lose a little more weight and get away with it, I would prefer to just maintain what I have. When I go lower than 120g, I end up struggling to eat sufficient calories. The primary reason I low carb is to manage my blood sugar levels, and more specifically, avoid dawn phenomenon on MDI.

Now in general, and up to this point my blood sugar results have improved, my latest a1c's have been consistently in the 7% range and I'm continuing to make progress. On a higher carb diet, my a1c's are generally in the 8% range.

One concern I have after recent reading is the possibility that a low carb diet could in fact increase insulin resistance in the long term. When I read that I thought, no way, we all know this works, right? What I am less sure of is what the long term implications are with respect to insulin resistance. Does it remain at a fixed level, get progressively worse, is it even an issue given my current carb intake, or is it just a lie based on skewed data?

The law of small numbers should be familiar to those who have read Dr B's book. I'm just trying to make sure that the insulin numbers I'm dealing with here remain small.

I do exercise a reasonable amount which generally improves my insulin sensitivity, so if there is any insulin resistance developing, I don't see any evidence of it. To the contrary, during half marathon training I've seen my insulin sensitivity improve by 16% over 4 weeks.

 

[Petrel]

Hi Zicksi
Great question about long-term implications of a low carb diet re insulin resistance. I'm new myself and it would be most interesting to see what long-term low carbers have experienced.

 

[tim2000s]

You need to take great care here and separate the two issues out in T1 and T2.

In T2, the issue is a link between too much insulin and insulin resistance (that seems to be linked to too much insulin and inflammation). Therefore low carbing reduces insulin resistance due to the body becoming used to not producing as much, and when not producing as much reducing body fat, so you end up with a virtuous circle.

In T1, its' a little different. In theory, the additional fat eaten could cause insulin resistance, however, from a purely anecdotal point of view, the things that decrease my insulin sensitivity are reduced exercise and increased carbs? Why? In principle, I think this is because eating more carbs needs more insulin and forces you to lock in fat, which in turn increases insulin resistance. Reduced exercise dials down my muscles ability to use store glycogen, and lets not forget, T1s do nearly all their conversion in their musculature unlike T2s who are doing 70% in the liver.

So my experience of eating low carb (which I've been doing for the most part for 18 months, isn't that I get an increase in insulin resistance from it.

 

[noblehead]

At 120g of carbs a day I doubt it, I was eating around this level before increasing it to my present level and didn't experience insulin resistance, some type 1's that do follow a very low-carb (<50g) can develop some resistance but usually find the drug Metformin is helpful in this respect.

 

[Wurst]

I low carbed strictly for 3 years i.e less than 30 grams per day. I ended up with cholesterol problems (high LDL) . Before I gave up low carbing I was experiencing insulin resistance. The immediate effect of dropping fats (especially saturated fats) improved my insulin sensitivity quite dramatically and once my LDL was back into normal levels, insulin sensitivity went to another level again (HB1AC was 4.9 %).

I later found out I have a hereditary cholesterol problem, so LCHF was never going to work for me long term. One thing that i find always improves insulin sensitivity no matter what diet you are on is strenuous exercise , so you're on the right path there!

 

[tim2000s]

I think it's an interesting one. The initial basis of eating low carb, will, for most people result in the loss of body fat. Just the basis of losing body fat will improve insulin resistance. From there it seems to be a multi-variable path which is somewhat dependent on your own physiology.

 

[zicksi101]

Thanks for the replies all, my experience so far is similar to @tim2000s in that low carbing has in fact improved my insulin sensitivity. This happened when I initially went on the diet and since then I haven't see any evidence to suggest insulin resistance. Refined carbohydrate is what I am most insulin resistant to at present.

I suspect that for T1, it becomes highly individual once you hit the weight loss plateau, and it is then largely a case of being mindful about the numbers.

 

[Roytaylorjasonfunglover]

As I understand if you go a on a very lowcarb diet for a prolonged period of time, you will get physological insulin resistance. If your body gets no substantial amounts of glucose regularly dumped in its system, your enzymes for carbohydrate metabolism is going to be downregulated. Look at this article for an explaination of the phenomen http://wholehealthsource.blogspot.com/2010/11/glucose-tolerance-in-non-industrial.html

 

[zicksi101]

Thanks @Roytalorjasonfunglover. To be honest I find it hard to draw conclusions from an older study like that because, for me as an individual, all carbs are not equal.

For natural carbs such as fruit, my ratio is lower than 1u for 25g (still working it out), this is actually less than what I have to bolus for protein! However I should caution here that many do not seem to tolerate fruit based carbs well and this causes their blood glucose to spike.

Refined carbohydrates, though, are a completely different matter. I have to bolus 1u for 10g in that case.

So, basically, the ideal diet for me is just to eat real food.

Mainly I was interested in sharing experiences here as it seems the conventional high carb low fat is a cause of insulin resistance in most cases for the world we live in today, despite what conventional therapy suggests.

 

[zicksi101]

So I thought I should come back to this to post my thoughts having recently developed insulin resistance. I have been offered Metformin for this.

I gave up low carbing and decided to actually go about getting some results.

The purpose of low carbing for me was not to lose weight, it was to limit insulin. However, I have looked back at my notes, and I see that, over time, I have tended to increasingly snack more on foods containing protein, resulting in more gluconeogenesis.

I feel perfectly satisfied when I eat foods containing carbohydrates, but eating foods with less carbs leaves me feeling somewhat deprived even today, with the result that I end up eating more protein.

When low carbing, I have never been in ketosis.

I am now doing an intermittent fasting diet, where I simply do not eat after dinner (unless hypo) which has had much better results for me. My resistance to insulin has reversed somewhat, with my evening levemir dropping from 16u to 13u, and blood sugar levels are no longer ending up high in the morning. During the day, I eat normally, can achieve controlled blood sugars, and certainly it is harder to eat a calorie surplus when you are busy and have work to do!

Then, nutritional ketosis. I didn't stay there for long, but my ketone level was 1.5 mmol/l towards the end of the fast on the 5th day, so it is clear that I have burned some fat there.

Hopefully that gives some context as to why it did not work for me. Just because a food does not contain carbohydrates, does not necessarily mean it is okay to eat it.

 

[kev1]

So I thought I should come back to this to post my thoughts having recently developed insulin resistance. I have been offered Metformin for this.

I gave up low carbing and decided to actually go about getting some results.

The purpose of low carbing for me was not to lose weight, it was to limit insulin. However, I have looked back at my notes, and I see that, over time, I have tended to increasingly snack more on foods containing protein, resulting in more gluconeogenesis.

I feel perfectly satisfied when I eat foods containing carbohydrates, but eating foods with less carbs leaves me feeling somewhat deprived even today, with the result that I end up eating more protein.

When low carbing, I have never been in ketosis.

I am now doing an intermittent fasting diet, where I simply do not eat after dinner (unless hypo) which has had much better results for me. My resistance to insulin has reversed somewhat, with my evening levemir dropping from 16u to 13u, and blood sugar levels are no longer ending up high in the morning. During the day, I eat normally, can achieve controlled blood sugars, and certainly it is harder to eat a calorie surplus when you are busy and have work to do!

Then, nutritional ketosis. I didn't stay there for long, but my ketone level was 1.5 mmol/l towards the end of the fast on the 5th day, so it is clear that I have burned some fat there.

Hopefully that gives some context as to why it did not work for me. Just because a food does not contain carbohydrates, does not necessarily mean it is okay to eat it.

Sorry, I meant to press the 'informative' icon not the heart! This thread has been really interesting and helpful.