The effect of protein in a T1 on low carb

[tim2000s]

By accident last night, I got an interesting trace on the Libre depicting the impact of protein on blood glucose levels.

I'd been the the gym, and as often I do, eaten a very low carb meal afterwards. The previous night I'd gone to bed with a lower glucose level that was perhaps a little too low so the protein in the meal had bounced me along the verge, but just held me up.

Last night I decided that I'd go to bed a little higher. I ate a 150g fillet steak at about 9pm, (33g protein roughly) with roughly30g of fried onions. If you look at the graph below, there is a rise from an 8pm hypo caused by protein shake and the end of the earlier levemir. I can't split those apart so I have to ignore it for these purposes. Ignoring the drop at about 1am, which I think was caused by the sensor playing up as the trace disappears for half an hour or so, you see that by a little after two, my glucose level is up at around 11, where it remained until I got up at 4.30. Blood tests confirmed the level to be correct.

Given there had been essentially no carb ingestion, I believe the only place this could have come from was the steak. Goes to show that 'complex' protein related increases can take sometime to kick in.

There is limited ability to bolus when eating for an increase like that as the increase occurred 5 hours after food. Unlike whey protein, which seems to have a much more rapid effect, I don't see that there is a lot that one can do, other than perhaps increase basal levels of insulin, or monitor and increase rapid acting as the levels start to rise.

In this case the increase is around 4mmol/l, which wasn't catastrophic, but isn't really what one wants to see.

 

[diamondnostril]

Hi Tim . . .

Protein has a big impact on my levels in the 18 hours or so after eating, if I eat too much of it.

When I eat Carbs, I must bolus for the immediate-term, and add extra Insulin the next day.

When I overeat Protein, I must add extra Insulin the next day.

(For me, "too much" Protein means more than 1g PRO for each KG of ideal body-weight, in my case 65)

To get around this problem I restrict my meat choices to Pork (pork-belly, bacon, high-fat pork sausages) and Duck and Lamb. For these meats the ratio of PRO/FAT allows me to eat a chunk of meat that satisfies me (250g - 300g) and still stay under the limit of PRO that will present problems over the next 18 hours. I can't do this with Chicken, Turkey, Beef, as the PRO ratios are too high.

For me, this delayed reaction (to both Carbs and Protein) is understandable. We know that excess Carbs and Protein are both directed to the liver to be stored as Glycogen, and that Glycogen is the fuel that powers Gluconeogenesis. What I found impossible to master regarding Gluconeogenesis was the timing. Often I would get a spike in the next morning, so-called dawn phenomenon, and sometimes the spike would not come until lunchtime or afternoon the next day. Therefore it was difficult to adjust Basal; I needed to wait for the spike and then correct. This made my control look awful, with a spike at some point every day.

I got fed up with this, and in the end just switched my choice of meats. This enabled me to continue eating enough to feel satisfied but without going over budget on the Protein. Now, spikes caused by Gluconeogenesis are pretty rare.

Regards
Antony

 

[tim2000s]

Interesting @diamondnostril . Were you seeing a sudden spike or a slower increase? My protein lifts tend to take around an hour when compared to the carb jumps which can take ten-fifteen minutes.

 

[noblehead]

For low carb meals I have to split-dose to allow for the slow digestion of protein, if I inject the full dose ahead I'd go hypo, so splitting the dose is the only option.

Before starting on insulin analogues I was using an insulin called Actrapid, on reflection this insulin would be better suited to low carbing as it has a longer profile that would be better suited to such meals.

 

[diamondnostril]

Interesting @diamondnostril . Were you seeing a sudden spike or a slower increase? My protein lifts tend to take around an hour when compared to the carb jumps which can take ten-fifteen minutes.

Can't answer this . . . maybe I collected more detailed information at the time; but if I did I can't remember it. I normally measure my level 4 times each day, so when I look back at my records of these times now, I only see the 4 daily numbers. I know you're a Libre fan . . . another argument in favour

 

[tim2000s]

For low carb meals I have to split-dose to allow for the slow digestion of protein, if I inject the full dose ahead I'd go hypo, so splitting the dose is the only option.

Before starting on insulin analogues I was using an insulin called Actrapid, on reflection this insulin would be better suited to low carbing as it has a longer profile that would be better suited to such meals.

Yes, I was on Actrapid some time back too. I think it would probably handle the protein rises better than Novorapid, although on a pump (or with an iport) a couple of boluses separate a little is no issue.

 

[noblehead]

Yes, I was on Actrapid some time back too. I think it would probably handle the protein rises better than Novorapid, although on a pump (or with an iport) a couple of boluses separate a little is no issue.

It would be a better insulin IMHO if your going to continue with very low carb diet in the long-term, they still make it so it might be worth enquiring about, with a pump you can use the extended bolus feature.

 

[tim2000s]

It would be a better insulin IMHO if your going to continue with very low carb diet in the long-term, they still make it so it might be worth enquiring about, with a pump you can use the extended bolus feature.

Looking at the macros on the food I am eating, this is going to require 3 insulins. Novorapid for higher carb (I do a cyclic pattern which means carb loading on Saturdays, although for brown rice and sweet potato, I'm not so sure that Novorapid is necessarily the most appropriate, looking at the Libre traces), however there are low carbs and they do have a more immediate effect that Actrapid necessarily gives.

Think I'm going to be doing the old "food testing" approach, whereby I ingest 10g of CHO or PRO of different types and track the blood glucose changes and then determine which insulins are best to handle it.

Hmmm. A pump, even with all its shenanigans, sounds a lot easier.

 

[Diamattic]

I have heard of this. I was told by my nutritionist that something like 1/3 - 1/2 of the protein eaten can end up being converted into sugars that can slowly elevate BG levels after 5-6 hours of eating the food. So 30g of protein, will act as if you've just eaten 10-15g of carbs 5 hours later..

I was told just to be aware of that after high protein meals, and that I may have to bolus for that.

 

[Ian DP]

I to have to watch protein. To much protein affects my BG levels for at least 6 hrs and sometimes I think as much as days. I am a T1 in the honeymoon period and not on insulin yet, so maybe I can see more clearly the effect of protein. I now avoid all lean meats, especially chicken breast. Lamb chops are great, as are pork chops and duck also find rump steak ok. Fried onions I always avoid, some sources indicate they are quite high carb. I avoid sausages, unless I know the ingredients (often high carb). If I eat meat in the evening I have seen my BG rise (very slowly) for hours, well into the next day.... I am only talking about a rise of 1mmol, but keep on rising it does.... Unless I do some exercising, this normally stops the rise. I have read 10g protein is equal to 5g carb, I think it is less than that, maybe 2.5 tor 3.5g.