Lentils and spikes!

[nabilla]

I've been wearing a cgm over Christmas. I've only had three incidences where I had spikes of over 7.9, backed up with finger prick tests. Twice times, I'd eaten red lentils. The first time it was a lentil and cauliflower curry. I also had three tablespoons of white rice and some onion bajis. The second time was some lentil and ham soup with no bread or any other food. The third time was when I added a small tangerine to my usual breakfast which I know doesn't spike me (30g jumbo oats with 60ml whole milk and water). I'm a little confused as I've not been spiked by having two small slices of Christmas cake or a big slice of spinach and cheese pie with roast potatoes. I'm back to my lowish carb diet tomorrow after these two weeks or relative excess at Christmas. I was diagnosed prediabetic in July and have brought my HBA1c down through lowish carb diet over 6 months to within normal range for UK. I'll keep using my glucose monitor to see how I'm doing when I have pulses and maybe try a tangerine another time, but wondered if it's possible to be sensitive to some foods (like lentils) and not others (pastry,!!). I also wondered if the spinach pie and roast potatoes were helped along by the fact they had lots and lots of butter, olive oil and feta through them whereas the lentil and cauliflower was low fat? The fact my cgm predicts an HBA1c of 27 after two weeks of high carb living makes me believe that raising my b12 levels has solved the problem. I've talked in other threads about the fact I was told I was low on B12 at the same time I was told I was prediabetic and there's some evidence to show low b12 can cause false high HBA1c readings

 

[Jo123]

I was pre diabetic over 10 years ago and have maintained a normal hba1c ever since.
Pulses spiked me too in the beginning.
I can eat them now, but only at lunchtime, a portion of 75gms is fine for me, but it would put me too high if I ate at the evening meal.

 

[KennyA]

You should expect your BG to rise after eating carbs. That's what they do. I don't consider a BG post-carby meal of over 7.9 to be a "spike" - sounds like a bang normal response. If you have a look at how non-diabetic people respond to carby meals through CGM responses -

Continuous Glucose Monitoring Profiles in Healthy Nondiabetic Participants: A Multicenter Prospective Study - PMC

Use of continuous glucose monitoring (CGM) is increasing for insulin-requiring patients with diabetes. Although data on glycemic profiles of healthy, nondiabetic individuals exist for older sensors, assessment of glycemic metrics with new-generation ...

pmc.ncbi.nlm.nih.gov

you'll see that non-diabetic people respond this way too. So it's maybe unhelpful to refer to these normal rises and falls as "spikes" which makes them sound a bit more dramatic than they actually are. The issue for those of us whose systems do not deal well with glucose is avoiding prolonged BG rises over time, which helps to avoid damage from higher levels of glucose. You'll have seen from your CGM that the peak BG normally occurs later in the first hour after eating, and what we're really measuring is the effectiveness of our systems in reducing that peak glucose to somewhere back near starting point.

There's also what's called the "pizza effect" where eating fat and carbs together can delay and/or slow the absorption of carb/glucose by the body. Some people report that this means a much longer period at higher levels. Personally, I would always prefer a shorter/higher rise and fall rather than a longer period spent at elevated levels, even if that never reaches as high.

I do think that we definitely show different responses to different sorts of carbs. Interestingly, I am fairly OK with lentils and pulses, BG hardly shifts, but cannot tolerate any amount of pastry at all. It seems with me to be an inability to deal with carb from flour.

Good luck with the B12 thing. I had a look in my Bilous and Donnelly Handbook of Diabetes, but they don't mention anything about B12 affecting HbA1c - there are several things that do.

 

[nabilla]

Thanks for the info about the 'spikes'. Very clear. What kind of level is an issue if it doesn't fall over a period of 2 or 3 hours? Here are some of the studies looking at false high HBA1c levels and B12 anaemia, which I had at diagnosis: https://pmc.ncbi.nlm.nih.gov/articles/PMC9677059/ this mentions b12 as well as other forms of anaemia https://www.sciencedirect.com/science/article/abs/pii/S1871402113000052 and https://scholar.google.com/scholar?...=#d=gs_qabs&t=1736002308612&u=#p=eE9xCJ07nHoJ
I have access to these peer reviewed papers but they are behind a paywall unless you're an academic or student. The studies are not massive, but there appears to be a clear link. My HBA1c was only slightly above the UK level for prediabetes on two occasions a year apart. I treated my b12 deficiency at the same time as adopting a lowish carb diet, so I dnt really know what's worked for me. What I do know is that my cgm projects an HBA1c of 27 after two weeks of eating a fairly high carb and sugary diet over Xmas. I show no signs of prediabetes or diabetes. This is backed up by 6 months of using a blood glucose meter for pre and post-prandial readings. I also had my HBA1c redone in Dec and it was at 37 instead of 42.

 

[SimonP78]

Thanks for the info about the 'spikes'. Very clear. What kind of level is an issue if it doesn't fall over a period of 2 or 3 hours? Here are some of the studies looking at false high HBA1c levels and B12 anaemia, which I had at diagnosis: https://pmc.ncbi.nlm.nih.gov/articles/PMC9677059/ this mentions b12 as well as other forms of anaemia https://www.sciencedirect.com/science/article/abs/pii/S1871402113000052 and https://scholar.google.com/scholar?hl=en&as_sdt=0,5&q=hba1c+and+vitamin+b12+deficiency+&btnG=#d=gs_qabs&t=1736002308612&u=#p=eE9xCJ07nHoJ
I have access to these peer reviewed papers but they are behind a paywall unless you're an academic or student. The studies are not massive, but there appears to be a clear link. My HBA1c was only slightly above the UK level for prediabetes on two occasions a year apart. I treated my b12 deficiency at the same time as adopting a lowish carb diet, so I dnt really know what's worked for me. What I do know is that my cgm projects an HBA1c of 27 after two weeks of eating a fairly high carb and sugary diet over Xmas. I show no signs of prediabetes or diabetes. This is backed up by 6 months of using a blood glucose meter for pre and post-prandial readings. I also had my HBA1c redone in Dec and it was at 37 instead of 42.

What were your HbA1c readings? The first study only shows a decrease of 0.24% (in the actual values, rather than as a percentage change of the values, which would be much much smaller) with treatment for B12 deficiency - I don't know whether the treatment brought the patients' haemoglobin values into the expected range mind you but one assumes it did or they would hopefully have commented on the fact!

The ones about iron deficiency and anaemia are more interesting, from a quick scan of the 2nd paper there certainly seems to be scope for quite a large overestimation of HbA1c for those with an iron deficiency and equally an underestimation for those with other types of anaemia. It's a shame they didn't put a summary table in the paper as wading through all the descriptions of the studies they studied (it was a meta-analysis) is painful.

 

[KennyA]

Thanks for the info about the 'spikes'. Very clear. What kind of level is an issue if it doesn't fall over a period of 2 or 3 hours? Here are some of the studies looking at false high HBA1c levels and B12 anaemia, which I had at diagnosis: https://pmc.ncbi.nlm.nih.gov/articles/PMC9677059/ this mentions b12 as well as other forms of anaemia https://www.sciencedirect.com/science/article/abs/pii/S1871402113000052 and https://scholar.google.com/scholar?hl=en&as_sdt=0,5&q=hba1c+and+vitamin+b12+deficiency+&btnG=#d=gs_qabs&t=1736002308612&u=#p=eE9xCJ07nHoJ
I have access to these peer reviewed papers but they are behind a paywall unless you're an academic or student. The studies are not massive, but there appears to be a clear link. My HBA1c was only slightly above the UK level for prediabetes on two occasions a year apart. I treated my b12 deficiency at the same time as adopting a lowish carb diet, so I dnt really know what's worked for me. What I do know is that my cgm projects an HBA1c of 27 after two weeks of eating a fairly high carb and sugary diet over Xmas. I show no signs of prediabetes or diabetes. This is backed up by 6 months of using a blood glucose meter for pre and post-prandial readings. I also had my HBA1c redone in Dec and it was at 37 instead of 42.

Anaemia is a well-known (well-known according to Bilous etc. anyway) cause of "spurious measurements" in HbA1c.

The standard advice re testing is that the post-meal reading at +2hrs should be within 2mmol/l of the initial pre-meal result, and not above 8.0. As an illustration, I have just run a test on some homemade tiramisu - I ate my meal at mid-day today so this evening was able to have a very generous portion of dessert in isolation and run a number of tests.

Before eating - 5.1.
At 45 minutes, probably around peak - 7.8
At 1 hr, 7.1
At 2hrs, 6.8
at 3 hrs, 5.6.

That's OK, just about, at two hours (double checked). The level didn't go up all that much but stayed up a bit longer than I'd like. That has probably something to do with the vast amount of cream in the pudding. Still not something I'm going to be doing all that often.

Those sort of values work for me in realation to a food I'm going to eat rarely - I'm used to my BG almost never shifting above 6. Others might take a different view about acceptable peak points etc.

 

[nabilla]

What were your HbA1c readings? The first study only shows a decrease of 0.24% (in the actual values, rather than as a percentage change of the values, which would be much much smaller) with treatment for B12 deficiency - I don't know whether the treatment brought the patients' haemoglobin values into the expected range mind you but one assumes it did or they would hopefully have commented on the fact!

The ones about iron deficiency and anaemia are more interesting, from a quick scan of the 2nd paper there certainly seems to be scope for quite a large overestimation of HbA1c for those with an iron deficiency and equally an underestimation for those with other types of anaemia. It's a shame they didn't put a summary table in the paper as wading through all the descriptions of the studies they studied (it was a meta-analysis) is painful.

Hi, the changes shown in the first study reflect almost exactly my own experience and give good results. If we convert the hbA1c measurements from percentage to mmol/mol, then the group begin at 42 mmol/mol (IFCC) +/- 2mmol/mol, so a range of 40-44 and by the end of the three month treatment with B12, have dropped to 40 +/- 3mmol. For me, that's enough to move from the UK's definition of prediabetic to normal. I was also treated for iron deficiency anaemia at the same time though and there have been studies showing this can cause odd readings, as Kenny A notes. It would be good to see larger, linger term studies as B12 deficiency and other anaemia are quite common, as is prediabetes. I intend to continue my lowish carb diet now then festive period is over, and I'll get my HBA1c done again next December. I'll be on B12 as well for the duration. The way I'm looking at it, I enjoy the lowish carb diet and it makes me.eat a lot more healthy and if I can break the rules now and then (ie Xmas, birthday, maybe a bit when we go on holiday) then I'll probably feel.better for longer regardless of whether or not I ever was actually showing signs of prediabetes or not.

 

[nabilla]

Anaemia is a well-known (well-known according to Bilous etc. anyway) cause of "spurious measurements" in HbA1c.

The standard advice re testing is that the post-meal reading at +2hrs should be within 2mmol/l of the initial pre-meal result, and not above 8.0. As an illustration, I have just run a test on some homemade tiramisu - I ate my meal at mid-day today so this evening was able to have a very generous portion of dessert in isolation and run a number of tests.

Before eating - 5.1.
At 45 minutes, probably around peak - 7.8
At 1 hr, 7.1
At 2hrs, 6.8
at 3 hrs, 5.6.

That's OK, just about, at two hours (double checked). The level didn't go up all that much but stayed up a bit longer than I'd like. That has probably something to do with the vast amount of cream in the pudding. Still not something I'm going to be doing all that often.

Those sort of values work for me in realation to a food I'm going to eat rarely - I'm used to my BG almost never shifting above 6. Others might take a different view about acceptable peak points etc.

Thanks, this is really useful. I'll look back through my notes and graphs

 

[Chris24Main]

Looks like you have this totally covered @nabilla - really impressive work.

 

[nabilla]

Anaemia is a well-known (well-known according to Bilous etc. anyway) cause of "spurious measurements" in HbA1c.

The standard advice re testing is that the post-meal reading at +2hrs should be within 2mmol/l of the initial pre-meal result, and not above 8.0. As an illustration, I have just run a test on some homemade tiramisu - I ate my meal at mid-day today so this evening was able to have a very generous portion of dessert in isolation and run a number of tests.

Before eating - 5.1.
At 45 minutes, probably around peak - 7.8
At 1 hr, 7.1
At 2hrs, 6.8
at 3 hrs, 5.6.

That's OK, just about, at two hours (double checked). The level didn't go up all that much but stayed up a bit longer than I'd like. That has probably something to do with the vast amount of cream in the pudding. Still not something I'm going to be doing all that often.

Those sort of values work for me in realation to a food I'm going to eat rarely - I'm used to my BG almost never shifting above 6. Others might take a different view about acceptable peak points etc.

Hi Kenny A,

I did a similar test to you and I wondered if this is normal for a non-diabetic? I think it is, but not sure:

I ate a small portion of black chickpeas (Kala chana) with a salad and one very small bite of a wholemeal chapatti with ghee. After, I had a bowl of full fat yoghurt with 6 blackberries, milled linseed and 4 walnuts. I used my blood glucose meter (fingerprint tests)

Before eating: 5.2
1h after eating: 8.9
2h after eating: 6.3
3h after eating: 5.7

Any thoughts? I'm having a much lower carb dinner tonight, so I'll test again with that.

 

[Chris24Main]

@nabilla - I had a meal around new year that was about half chick peas - I love chick peas, and probably miss them more than any other pulse -

But - I felt totally different in the way my body digested the meal - I swear after a year of very low carb, I can feel when food is diverting to the liver.. I wasn't wearing a CGM at the time, but I felt all the symptoms I would expect from this kind of spike, and all gone in about the same time.

My sense - while you are in a state of transition, you are simply much more sensitive to these kind of things - that portion of Chick Peas will affect you in ways that you wouldn't have thought possible, and you would never have even noticed previously.

What I'm looking forward to figuring out, is what can I do after this period of transition - I'm not willing at this moment to commit to never having chick peas again...

 

[nabilla]

@nabilla - I had a meal around new year that was about half chick peas - I love chick peas, and probably miss them more than any other pulse -

But - I felt totally different in the way my body digested the meal - I swear after a year of very low carb, I can feel when food is diverting to the liver.. I wasn't wearing a CGM at the time, but I felt all the symptoms I would expect from this kind of spike, and all gone in about the same time.

My sense - while you are in a state of transition, you are simply much more sensitive to these kind of things - that portion of Chick Peas will affect you in ways that you wouldn't have thought possible, and you would never have even noticed previously.

What I'm looking forward to figuring out, is what can I do after this period of transition - I'm not willing at this moment to commit to never having chick peas again...

Hi, how does your body feel after the chickpeas--what are your symptoms? Do you have any thoughts on the BG readings I shared?

 

[Chris24Main]

... ok - so I was trying to avoid describing this, but I guess I asked for it....

When I eat mainly fat and protein together - I do not feel "stretched" in the stomach, but I feel full. Then - I can feel that food progressing straight "down" and after some time I have a fairly well defined bowel movement, after which my entire system feels "empty".

When I have pulses, or anything with starch - I feel quite bloated during the meal itself, and full, but not in a satisfied way. I can feel that food progressing "sideways" - I've taken to thinking that I can literally feel food being diverted straight to the liver - but I just don't know if that is even possible, all I can say is that it feels different, now that I'm so attuned to .. not eating starches.

I also feel a kind of tight, slightly sick feeling around my stomach. Ringing in my ears, slight buzzing, often a bit of a headache. After some time, I have a bowel movement that feels totally unsatisfying, like I immediately need to go back to the toilet.

My energy levels fluctuate in ways that I can relate to swings in blood glucose - (this sounds a little vague, but mainly because I was not wearing a CGM, so I cannot say for sure, but I would put money on my blood levels being pretty close to yours through this time period).

More generally - thoughts... I hear over and over how these blood glucose rises and drops are totally natural and a biological response to food that we all have. At the same time, others call them inflammatory and aging. I think both are true. I think a hangover is a totally natural reaction to alcohol, but it is inflammatory and aging also.

So - while trying to transition to being more metabolically flexible, I think it's better to keep insulin low, and allow my body to manage the blood glucose by producing it when necessary.

 

[KennyA]

Hi Kenny A,

I did a similar test to you and I wondered if this is normal for a non-diabetic? I think it is, but not sure:

I ate a small portion of black chickpeas (Kala chana) with a salad and one very small bite of a wholemeal chapatti with ghee. After, I had a bowl of full fat yoghurt with 6 blackberries, milled linseed and 4 walnuts. I used my blood glucose meter (fingerprint tests)

Before eating: 5.2
1h after eating: 8.9
2h after eating: 6.3
3h after eating: 5.7

Any thoughts? I'm having a much lower carb dinner tonight, so I'll test again with that.

It looks like a fairly standard response to some carb. I can hit mid nines in the first hour after a small latte (hot milk seems to get processsed very quickly), so I'm not that concerned, within reason, about how high a very short rise goes.

I guess the issue for me with that sort of result might be that if that's the response to "a small portion", I might not want to be adding any more carb to that meal.

Your response is on target at 2 hours and probably effectively over by three. Depending on what else is going on, that looks OK, for now. I will occasionally re-check things I think I know about, just to be sure nothing has changed.

 

[Omar51]

I've been wearing a cgm over Christmas. I've only had three incidences where I had spikes of over 7.9, backed up with finger prick tests. Twice times, I'd eaten red lentils. The first time it was a lentil and cauliflower curry. I also had three tablespoons of white rice and some onion bajis. The second time was some lentil and ham soup with no bread or any other food. The third time was when I added a small tangerine to my usual breakfast which I know doesn't spike me (30g jumbo oats with 60ml whole milk and water). I'm a little confused as I've not been spiked by having two small slices of Christmas cake or a big slice of spinach and cheese pie with roast potatoes. I'm back to my lowish carb diet tomorrow after these two weeks or relative excess at Christmas. I was diagnosed prediabetic in July and have brought my HBA1c down through lowish carb diet over 6 months to within normal range for UK. I'll keep using my glucose monitor to see how I'm doing when I have pulses and maybe try a tangerine another time, but wondered if it's possible to be sensitive to some foods (like lentils) and not others (pastry,!!). I also wondered if the spinach pie and roast potatoes were helped along by the fact they had lots and lots of butter, olive oil and feta through them whereas the lentil and cauliflower was low fat? The fact my cgm predicts an HBA1c of 27 after two weeks of high carb living makes me believe that raising my b12 levels has solved the problem. I've talked in other threads about the fact I was told I was low on B12 at the same time I was told I was prediabetic and there's some evidence to show low b12 can cause false high HBA1c readings

I eat lentils, only lentils and very little. Lentils and rice give me a big spike. So I don’t eat rice at all. I use to eat steel cut oats with little milk and that gave me a big spike too. So no more oats for me. Now I have been eating very very low carbs or sometimes no carbs.
Obviously in diabetic world we all are one of a kind. I have been calling myself pre diabetic for about fifteen years, and no medicine. If I eat regular food within days I am Type two diabetic.

 

[nabilla]

I eat lentils, only lentils and very little. Lentils and rice give me a big spike. So I don’t eat rice at all. I use to eat steel cut oats with little milk and that gave me a big spike too. So no more oats for me. Now I have been eating very very low carbs or sometimes no carbs.
Obviously in diabetic world we all are one of a kind. I have been calling myself pre diabetic for about fifteen years, and no medicine. If I eat regular food within days I am Type two diabetic.

Hi, I don't eat rice at all now either, or chapattis/bread/naan etc. anything with flour seems to put my glucose levels very high. However, I do not have issues with jumbo oats if I measure a small portion (30g) and eat with 60ml whole milk and water and half a pear with toasted almonds. This morning I was at 5.6 before eating this breakfast and two hours after I was at 5.5 (using finger prick meter). I was told I was prediabetic in July but low carb diet has reduced my HBA1c levels to normal. I enjoy it for the most part, but do miss some foods!